Delay-line anode detector based on MCP electron multiplier detect the incident photon’s location by the arrival time difference of the MCP output charge pulse at each end of delay line. Due to their high spatial resolution and high counting rate, photon counting detectors with delay line anode have been widely used in ultraviolet spectral imaging systems. Operational principle of ultraviolet photon detector based on delay line anode is analyzed, and a novel two-dimensional serpentine delay line anode is designed. Electron cloud output from MCP is collected only by the anode surface. The upper serpentine delay line receives the MCP output charge directly, while the lower serpentine delay line receives the charge using a series of pads and vias. This anode is made of printed circuit board instead of laser etching, which greatly simplifies the fabrication process. Photon counting detector with this type of anode achieves a 92 μm FWHM resolution. And the image linearity is better than 100 μm. The results of theory analysis and experiments demonstrated the feasibility of ultraviolet photon imaging system. It provides a theoretical basis and experiments guidance for the development of ultraviolet imaging spectrometers.

Emission spectroscopy was used to analyze the plasma spray physical vapor deposition (PS-PVD) jet of different gas compositions and Abel inversion was used to calculate the spectral intensity of radial point to get the gas distributions of different gases. Multispectral line slope method was used to study the impact of radial distance and gas composition on electronic temperature. Radial distribution of electronic density was calculated by stark broadening. The results showed that: in Ar/H2 gas, H2 was well-distributed in the 0-30mm area and increased with radial distance in the 30~60 mm area; After adding He gas, the concentrations of Ar and H2 were low at the centre of jet and increased with radial distance, and He gathered at the centre of plasma jet; Electronic temperature and density decreased with the increase of radial distance, at the same time, influenced by H2 and He.

Collisional deactivation rate constants, k5(M) for HBr(Χ1Σ+ ν″=5) by M= H2, N2, CO2, and HBr were obtained using the degenerated stimulated hyper-Raman (OSHR) pumping method in a pumping-probe configuration. High- resolution transient laser induced fluorescence (LIF) was used to detect collisionally relaxed HBr. For M=CO2, an efficient near-resonant 1-1 vibration-to- vibration (V-V) energy exchange was observed. It appeared that the presence of a strong infrared-active vibrational mode was a favorable situation for an efficient V-V energy transfer. A 1-1 resonance exciting the infrared forbidden N2(1←0) vibration was also observed, but it was 2 orders of magnitude smaller than that of CO2. Self-relaxation rate constants of HBr (ν″=5) were measured. Single quantum relaxation accounted for about 70% of the total relaxation out of state ν″=5, and two-quantum relaxation made contributions (25%) to the vibrational relaxation at this vibrational energy. Direct evidence for 2-1 resonance in HBr (ν″=5)+H2 was observed. Initial preparation of HBr (ν″=5) resulted in nearly no population in HBr (ν″=4), but direct population of HBr (ν″=3). Therefore only 2-1 resonant energy transfer was important for H2 relaxation. The state specific rate constant for HBr was obtained by the analysis of the state-to-state relaxation data. It was found that the data could be fitted with one adjustable normaligation parameter using a single-quantum relaxation model, which restricted the rate constant. A strong mass effect on the vibrational relaxation rate constant was observed. A further check of the character of the V-V resonant energy transfer in highly vibrationally excited HBr was the temperature dependence of the rate constants. For M=CO2, the temperature dependence of the 1-1 near-resonant energy transfer rate constats was found to be inverted. In contranst, the temperature dependence of the relaxation rate constants for M= H2 and HBr was normal. For M=N2, a weak but position temperature dependence was found. It suggested that this resonance occurred by a different mechanism compared with that in CO2.

In the non-invasive tissue composition detecting, the diffuse reflectance spectroscopy could be affected by the measurement conditions, especially the tissue deformation induced by the contact pressure. In this paper, the physical model was simulated to quantify the changes of tissue thickness, optical properties and diffuse reflectance induced by the contact pressure, respectively. Firstly, based on the physical complex model and solid-liquid mixture composition of biological tissue, the deformation and changes of the water under contact pressure were quantitatively analyzed. In this model, the skin tissue was modeled as the elastic structure filled with Newtonian fluid. Then, the finite element method was applied to simulate the time-varying deformation of tissue under certain contact pressure. Secondly, the scattering and absorption coefficients of tissue were calculated with the quantitative results of the deformation and water migration in the three-layered skin tissue. After that, Monte Carlo method was used to simulate the light propagation within the tissue under different pressures. Finally, the effective information contained in the diffuse reflectance spectrum was analyzed to quantify the influence of the contact pressure. The results showed that the reduction of thickness and water content in dermis resulted in the decrease of effective information contained in the diffuse reflectance spectrum. The conclusions of this paper are beneficial for optimizing measurement strategy and improving accuracy and repeatability of the in vivo diffuse spectroscopy measurements.

As an in-situ, fast and noninvasive mid-infrared spectroscopy technology, ATR-FTIR has been increasingly applied in many engineering fields, particularly in in-situ real-time measurement of the solution concentration during a crystallization process. Water is a common solvent for crystallization, which has very strong absorption peaks in the mid-infrared range but has different spectra absorbances under different temperature. Thus, the affects from water and its temperature could not be ignored in measuring the solution concentration in the mid-infrared range. Based on the Lambert-Beer’s law, it is proposed in this paper to subtract the pure solvent spectra from the solution spectra under the same temperature to accurately measure the solution concentration. Take the L-glutamic acid (LGA) solution as a case for illustration. Three calibration models were established for comparison by using the original spectra of LGA aqueous solution, the original spectra deducted uniformly by the water spectra under room temperature (25 ℃), and the solution spectra deducted by the water spectra and measured under the same temperature, respectively. The results demonstrated that the proposed temperature-related differential spectra measurement method could effectively eliminate the influence of solvent on the spectra. The proposed method has a referential value for improving in-situ ATR-FTIR spectra measurement accuracy in practice.

Artemisinin and its derivatives: dihydroartemisinin, artemether, artesunate, are a group of sesquiterpene lactone with a 1, 2, 4-trioxane ring system and possess a rapid action against malaria. Due to its pharmacological features such as efficiency, low toxicity, low cost, safety and so on, they have become one of the most widely used antimalarial drugs. However, there are still some ambiguity in the current terahertz fingerprint spectrum data, which is difficult for the rapid and nondestructive identification of these drugs. In order to further improve the terahertz fingerprint data of artemisinin and its derivatives, here, the terahertz time-domain spectroscopy (THz TDS) was used to measure the THz spectra of artemisinin, dihydro artemisinin, artesunate and artemether, and the characteristic absorption spectra were obtained in the range of 0.2 to 2.7 THz. Compared with the experimental results and the previous reported data, our experimental data showed that most of the resonance peaks were consistent with the literature [3], but the peak position and intensity were slightly different, and some new peaks were observed. Furthermore, the influence of sample preparation, data processing method on the results and the relationship between molecular structure and peak position were discussed, and the validity of the data was confirmed. This study provides a reference for the further study on the properties of artemisinin and its derivatives, and provides a rapid and effective method for the identification and quantitative analysis of artemisinin and its derivatives.

Terahertz (THz) radiation is the electromagnetic spectrum lying between the microwave and infrared portions, and covers wavelength between 3mm and 30um. Terahertz spectroscopy has been used in qualitative and quantitative analysis since molecular vibrations and rotations of a great large number of materials lie in this region. Many techniques, such as principal component regression (PCR) and partial least square regression (PLSR), have been applied in quantitative analysis of terahertz time-domain spectroscopy. However, those “soft-modeling” methods, though effective in many cases, all require a large number of samples and have poor extrapolation capability, and the utilization is also restricted in some cases (samples lack or requirement of extrapolation). A parametric method of spectrum, Indirect Hard Modeling (IHM), was proposed to resolve terahertz spectral matrix and quantify the mixtures. Savitzky-Golay method was used to eliminate the influence of noise. Moreover, the features of terahertz spectra were considered and the artificial baseline was also resolved as a signal spectrum to improve spectrum extraction accuracy. Subsequently, the analysis of IHM was carried out, and the ability of prediction and accuracy of the model in the case of low training samples were discussed. In order to validate the capability of the proposed method, quaternary systems of Rifampicin, Lactose monohydrate, microcrystalline cellulose and magnesium stearate were tested. The regression correlation coefficient (R) and root mean square error (RMSE) were employed to estimate the performance of the model. Finally, the comparison of IHM and PLSR were carried out, and theoretical analysis and experimental results indicated that the number of samples required by IHM modeling could be reduce to two during calibration, at the same time, the accuracy of quantitative and extrapolation capabilities were also improved.

Leaf moisture is an important parameter of plant health, and Terahertz is sensitive to leaf moisture. When terahertz spectra penetrate the leaf, the leaf can be imaged according to different moisture contents at different positions. In this research, Terahertz technology was used to detect the isolated leaf moisture. The relationship between leaf moisture and terahertz spectroscopy data was studied. Terahertz data were obtained by scanning the leaf in vitro. Then the time domain amplitude was obtained and the frequency domain spectra were extracted to rebuild the leaf images. The distribution of the leaf moisture could be clearly observed. This study showed that the image quality with the minimum time domain performed the best. Also, the optimal model was established. The correlation coefficient and the root mean square error of the prediction model were 0.981 7 and 0.023 7 g, respectively. The result of the research provides a guidance to predict live leaf moisture using Terahertz technology in the future.

LaSi3N5∶Ce3+blue phosphors were prepared by carbothermal reduction method. The influence of C content and heat-dealing on purity and luminescence of samples were investigated. The phosphors were characterized by X-ray diffraction (XRD) and fluorescence spectrophotometer (PL). XRD patterns revealed that LaSi3N5∶Ce3+could be combusted at 1 600 ℃. There was a single-peak broadwide emission spectrum between 380~600 nm due to the electron transfer of Ce3+ from 5d-4f excited by 360 nm. The luminescence intensity reached the maximum value atnC/nLa=4/1 followed by a continuous decline with a red shift and then a blue shift appeared in the spectrum. The luminescence intensity of samples improved 60%~345% after heat-dealing. WLED were fabricated by applying a blend mixture of the sample and commercial YAG on a UV chip (λ blend m), which indicated that LaSi3N5∶Ce3+blue phosphor had a potential application value in WLED.

In the case of infrared spectroscopy for the monitoring of unknown gas components, it is necessary to qualitatively identify the gas components. LASSO variable selection technique based on multiple linear regression model is widely used in data analysis. In this paper, the LASSO method is introduced into the field of infrared spectroscopy, and a qualitative identification method based on LASSO variable selection technique combined with cyclic least squares (LCLS) analysis is proposed and verified by relevant experiments. The absorbance spectra of six components of CO, C2H4, NH3, C3H8, C4H10, C6H14, and the absorbance spectra of a mixture of C2H4 and NH3 were measured. The LASSO method was used to analyze the collected spectra with the spectra library build by our lab, and then the LCLS method was used to eliminate the interfering components. The experimental results show that LASSO combined with LCLS can effectively identify the target components in the spectrum, even in the spectral band with serious interference, most of the interference components can also be removed.

The good near-infrared spectrum quantitative analysis models -of edible oil and the model sharing between different instruments can improve the utilization of the models and meet the needs of edible oil industrial development. The research mainly investigated the application of the direct standardized algorithm in the calibration transfer of the acid value and peroxide value of edible oil. 50 samples were selected including soybean oil, peanut oil, sesame oil and corn oil. The experimental instruments were VERTEX 70 Fourier Infrared Spectometer and Antaris Ⅱ Fourier Near-Infrared Spectrometer (including fiber probe and transmission probe). Three groups of experiments were carried out: The first group used the master instruments, VERTEX 70 and the slave instrument, Antaris Ⅱ (fiber optic probe components); the second group used the master instrument, the VERTEX 70 and the slave instrument, Antaris Ⅱ (the transmissive component); and the third group used the master instrument, Antaris Ⅱ (Transmissive Part) and the slave instrument, Antaris Ⅱ(Fiber Part). Depending on the direct standardization algorithm and the partial least square correction model of the master instrument, the calibration transfer was studied on the near-infrared spectroscopy model of the acid value and the peroxide value of the edible oil. The experimental results showed that for VERTEX 70 and Antaris Ⅱ (fiber optic probe components), the mean square errors of the acid value and peroxide value before and after the calibration transfer were 54.675 6 and 1 912.219 4, respectively, and their mean square errors reduced to 0.560 13 and 4.835 6, respectively, after using the direct standardized algorithm. The direct standardization algorithm has fairly good effects on the calibration transfer of the acid value and peroxide value of edible oil between the instruments with the same principle and acid value compared to the peroxide value. The research results are of importance for the wide application of the quick quantitative analysis model of edible oil.

The current unmixing of rock thermal infrared spectrum mostly focuses on granule forms, which can’t meet the requirements of high accuracy when applied to natural massive rocks. This paper aims to study the influence of rock surface roughness on spectral unmixing, which will influence the spectral emissivity and unmixing accuracy. Three grades of roughness were defined according to the natural rock surface morphology, and according to their structural forms, three kinds of samples were simulated by the method of mineral block mosaicking. The effects of roughness level on rock spectrum and unmixing were investigated by unmixing experiments using the same and different roughness grades. The results showed that good unmixing could be achieved when the mineral endmember and rock shared the same roughness, while in terms of different roughness grades, 48.3% of the 60 unmixing results presented errors over 5%, and the maximum was 25.3%. Therefore, we suggest that the effects of roughness on spectral unmixing should be completely considered in the quantitative hyperspectral remote sensing of natural massive rock.

In order to rapidly determine the content of raw juice in blending pear juice by near-infrared spectroscopy (NIR), experiments using the same soluble solids content of fresh pear juice and juice powder were conducted. Four common swarm intelligence optimization algorithms, including Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Glowworm Swarm Optimization (GSO) and Firefly Algorithm (FA), were combined with PLS to select wavelength variables. The results showed that the four kinds of models could remove most of the wavelength variables, and the FA-PLS model achieved the optimal performance, which simplified the model and improved the accuracy of prediction. Then, the successive projections algorithm (SPA) was used to select wavelength variables after Firefly Algorithm (FA). The results indicated the generalization ability were as follow: FA-PLS>PLS> FA-SPA-PLS>SPA-PLS. The root mean square errors of prediction (RMSEP) was 0.029 1, 0.033 3, 0.033 9, 0.137 0, respectively, and the corresponding wavelength variables number were 367, 765, 20, 18. The wavelength variables of SPA-PLS model were the least, but RMSEP was much higher than the other three models. Considering the prediction precision and the number of wavelength variables, the FA-SPA-PLS model was validly improved with less wavelength variables and higher prediction accuracy. This study provides a convenient way for rapid identification of blending fruit juice using NIR.

In order to study the adaptability of using different kinds of spectra to analyze the quality of Ginkgo biloba leaves quickly, 58 samples of Ginkgo biloba leaves were collected. The contents of the active components of flavonoid glycosides and terpene lactones were determined as dependent variables (y) by high performance liquid chromatography (HPLC), and the independent variables (x) included ultraviolet (UV), visible and near infrared spectra signals. Quantitative analysis models of flavonoids and lactones in Ginkgo biloba leaves were established by partial least square regression (PLSR) and an innovative method of keeping a same relationship between X and Y space (KNN-KSR method for short). The method predicted dependent variables based on the object’s independent variables and the relationship between the object and its K nearest neighbors in independent variable space. Correlation coefficient R between the measured values and the model values, root mean square error of prediction (RMSEP), and the average relative error of the prediction (MRE) were applied to evaluate the models. All evaluated indicators of PLSR models based on three kinds of spectral information were inferior to those of KNN-KSR method, and the results of PLSR models based on UV spectra were very poor; However, when KNN-KSR method was used to predict the flavonoids and lactones in Ginkgo biloba leaves based on three kinds of spectral information, R was higher than 0.8; RMSEP of flavonoids and lactones were less than 0.05 and 0.025, respectively; MRE of flavonoids and lactones content were below 8%. UV, NIR and multi-source composite spectral information combing KNN-KSR method could achieve rapid analysis of four kinds of flavonoid glycosides and three kinds of terpene lactones in Ginkgo biloba leaves. The present work broke through the limitation of existing work that only analyzed total flavonoids in Ginkgo biloba leaves by PLSR method based on NIR; The proposed new ideas to rapidly determine flavonoids and lactones in Ginkgo biloba leaves using UV and multi-spectral information by KNN-KSR method provided more available methods and choices for the quality analysis of ginkgo biloba leaves. The multi-source composite spectrometer, which can provide spectral information of various types, is portable, of small volume and low cost. It is very suitable for the rapid detection of on-the-spot Ginkgo biloba leaves acquisition and follow-up product quality analysis and monitoring.

Fritillariae thunbergii Bulbus, as one of the famous “Zhe Ba Wei”, is often used as expectorant and antitussive medicine. Sulfur fumigation is commonly good for whitening, mothproofing and extending the shelf-life of medicines. However, excessive sulfur fumigation will affect the quality of traditional Chinese medicines, even damage human health. Therefore, using non-destructive detection method of Fritillariae thunbergii Bulbus with sulfur fumigation is beneficial to monitor the quality of traditional Chinese medicines. This paper used near infrared spectroscopy (NIR) (900～1 700 nm) combined with chemometrics to detect the Fritillariae thunbergii Bulbus fumigated with different concentrations of sulphur. “Boxplot” was adopted to analyze the difference among the samples in the range of 1 000～1 100 nm. Principal component analysis (PCA) was also used to cluster analysis of six different samples. Then successive projection algorithm (SPA) was applied to extract ten different characteristic wavelengths and establish the partial least squares-discriminant analysis (PLS-DA) models. Results showed that PLS-DA model had the similar results with full spectra analysis. Furthermore, NIR combined with chemometrics can be used to analyze the Fritillariae thunbergii Bulbus fumigated with different concentrations of sulphur. It provided a theoretical reference for the analysis of the quality of Fritillariae thunbergii Bulbus and the design of the portable instruments.

A method for detecting melamine in milk powder was developed based on near infrared (NIR) auto-correlation spectroscopy. Forty pure milk powder samples and forty adulterated milk powder samples with different relative factions of melamine (10-4%~40%, w/w) were prepared. The NIR reflectance spectra of all samples were collected in the range of 10 000~4 000 cm-1. Synchronous two-dimensional (2D) NIR correlation spectrum was calculated under the perturbation of melamine concentration, and the 7 000~4 200 cm-1 region was selected to establish a model. Then, based on the extracting information of auto-correlation spectra, the classification and quantification models of adulterated milk powder were established using partial least square (PLS) method. The 100% classification accuracy and the root mean square errors of prediction (RMSEP) of 0.63% were achieved, while the classification accuracy and RMSEP were 96.2% and 0.84%, respectively, using conventional one-dimensional NIR spectra, which showed that the auto-correlation spectra could provide better results, probably because more characteristic information could be extracted than conventional one-dimensional NIR spectra.

There are various salmons of different varieties and prices at domestic salmon market. As Norwegian salmon can be sold at higher prices, the counterfeit problem of Norwegian salmon has become extremely serious in China. However, the identification methods are limited and it’s hard for consumers to identify different salmons. Therefore, a quick and accurate identification method is urgently needed. In the paper, infrared spectroscopy and partial least squares discriminant analysis (PLS-DA) were used to detect Norwegian salmon and three counterfeit Norwegian salmons (Heilongjiang salmon, freshwater rainbow trout, Chile Pacific salmon). The study used Fourier transform infrared (FITR) spectrometer and KBr pressed pellet method to acquire the original spectrum of the above four salmons. To eliminate interference factors such as noise and particles scattering, original spectra were preprocessed with multiplicative scatter correction (MSC), Savitzky-Golay, first derivative, standard normal variate (SNV) and peak area normalization respectively and the impact of each method on the model was studied as well. To establish PLS-DA model, spectra of the above four salmons were assigned reference score -3, -1, 1, 3 respectively at threshold range 1 to test the accuracy of the model. The results showed that PLS-DA model achieved the best performance when peak area normalization was used, with determination coefficient of calibration sets 0.97, cross validation sets 0.96, root mean square error of calibration sets(RMSEC) 0.37 and root mean square error of cross validation(RMSECV) 0.52. The model could significantly distinguish four salmons and achieved 96% accuracy when test sets was predicted. Mahalanobis distance method was also used in the study to find the differences of four kinds of spectra. The results showed Norwegian salmon had largest mahalanobis distance with rainbow trout and had smallest mahalanobis distance with Chile Pacific salmon, which was consistent with the difference of salmons’ species and living environments. In summary, infrared spectroscopy combined with PLS-DA is proved to be an effective method for detecting counterfeit salmons and the method may provide a way to distinguish other kinds of meat.

A new method of real-time identification of tissue’s thermal damage level based on near infrared (NIR)scattering spectroscopy was established. Firstly, 808 nm pulse lasers of 3.5, 5, 6.5 and 8 W were introduced separately into fresh in vitro porcine livers to make thermal damage. The NIR scattering spectra and temperatures were acquired respectively during heating at a distance of 10 mm from the center of the damage, and slopes of spectra between 830 and 900 nm (S830~900) were obtained by least-square estimation. Laser was switched off as S830~900 arrived at different times of original values. Secondly, tissues around the spectra sample points were taken to obtain histological analysis, and grades were given according to the tissues’ histological characteristics using 3 grades scoring system (score of 3 means full damage, score of 2 means partial damage and score of 1 means invalid damage). Finally, Correlations among S830~900’s largest rising amplitude during heating and its final steady value after cooling and thermal damage levels were analyzed-. Results showed that a full damage was received generally as S830~900 increased more than 4 times of its original value and finally stabilized at 3.5 times after cooling; an invalid damage was usually obtained as S830~900 increased 2 to 5 times and finally dropped to 1 to 1.5 times; and others could be identified as partial damage. In conclusion, based on the analysis results, relationships between spectra and thermal damage levels were established for the first time. For thermal damage identification, S830~900’s largest rising amplitude during heating combined with its final steady value after cooling has good evaluating effects which can decrease the impact on the results induced by individual differences and make a high accuracy of above 90%. Identification of tissue’s thermal damage level in real-time with a high accurate rate has been achieved, providing a new method for in vivo monitor of tissue thermal damage.

In order to discuss the feasibility of chemical composition of complete tobacco by near infrared spectroscopy analysis technique, we used near infrared spectroscopy analysis technique to study spectrum acquisition of the complete flue-cured tobacco leaves and total alkaloid quantitative analysis modeling methods. The samples of the flue-cured tobacco in this research were collected from different towns and different varieties in Kunming city of Yunnan province. Respectively with tobacco leaf tip, the middle part of leaf, leaf base spectrum and the three parts of the average spectrum to establish quantitative analysis model for total alkaloids of flue-cured complete tobacco leaves with Partial Least Squares (PLS); respectively use KS and SPXY methods to divide flue-cured tobacco samples into calibration set and validation set and use back interval partial least squares (BiPLS), no information on variable elimination method (UVE) and competition adaptive re-weighted sampling method (CARS) to select characteristic variables to optimize the model. Research results showed that, the prediction accuracy of the model established with tobacco leaf tip, the middle part of leaf, leaf base spectrum the three parts of the average spectrum improves 8.5%~9.5% compared to the model established with the spectra of the individual parts. Compared with full-spectrum modeling, using KS-BiPLS to establish the model can significantly improve the model’s predictive ability and the prediction accuracy of the model is improved by about 10%. The correction coefficient and root mean square error of the model are 0.917 4 and 0.226 1 respectively. The determination coefficient and root mean square error of the validation set are 0.902 0 and 0.200 7 respectively. This method is applied to flue-cured complete tobacco leaves and it can be used to estimate total alkaloids of flue-cured complete tobacco leaves content rapidly and non-destructive. It will save a lot of time for a large number of flue-cured tobaccos. And it will also help to provide technical support for the classification of the flue-cured tobacco leaves and improve the quality of raw materials and provide scientific basis for the process control of cigarette production.

Proteins are essential for living organisms because they are main components of the physiological metabolic pathways of cells. As an ultrasensitive technique, surface-enhanced Raman scatting (SERS) has been proved having a great potential in high throughput biomolecules detection, especially in proteins detection. In this paper, recent advances of the development of SERS probe technology were presented, such as immunogold-based method, Raman-active nanomaterial-based sensors, enzymatic-based sensors, and reagent-based sensors.

Great chemical and thermal gradient exists in deep sea hydrothermal vent environments, and rapid and turbulent mixing and biologic processes produce a multitude of diverse mineral phases and foster the growth of a variety of chemosynthetic micro-organisms. Raman spectrometer system is well suited to mineral speciation measurements and has been successfully used for deep sea hydrothermal environments detection so far. However, to further understand the interaction between mineral and microbial processes, a Raman system optimized for mineral identification that incorporates a fluorescence for microbial processes is necessary. In this paper, a combined Raman-fluorescence spectroscopy prototype was presented and some preliminary results were obtained. In this prototype, a double wavelength laser was used as the same excitation source for both Raman spectroscopy and fluorescence which worked at 532 and 266 nm, respectively. The laser was splitted into two paths based on wavelength and illuminated on the sample. The produced Raman and fluorescence signals were collected by a back-scattering optical set-up and coupled into a QE65000 and an USB2000 optical fiber spectrometer, respectively. With this prototype, we measured seawater and pseudo-nitzschia samples and got Raman and fluorescence spectra simultaneously for both samples, including sulfate Raman and CDOM fluorescence spectra in seawater sample, carotenoid Raman, proteoid and chlorophyll fluorescence spectra in pseudo-nitzschia sample. The results proved the feasibility of developing a compact Raman-fluorescence combined system for underwater detection.

The use of Raman hyperspectral imaging technique can obtain not only the spatial distribution information of samples, but also the spectral information of each pixel on the image. It has been applied in food safety testing for its abundant information. This study was aimed at quantitatively analyzing of light penetration depth through milk powder in Raman hyperspectral imaging, and exploring the influences of system parameters and types of milk powders. The attenuation of Raman signal in milk powder layer was also discussed. Milk powder layers with five different thicknesses ranging from 0.8~4.0 mm were prepared on the top of a melamine layer with 5 mm thick. The penetration depth of light was evaluated by detecting the characteristic peaks of melamine. The results showed that the Raman characteristic signal was enhanced with a bigger laser intensity and longer exposure time at the same thickness of milk powder layer. When the laser intensity was not less than 2 W and the exposure time was not less than 500 ms, the light penetration depth in whole milk powder was 4 mm at least. The peak intensities of melamine decayed in exponent with the thickness of milk powder layer increasing from 0.8 to 4.0 mm. The light penetration depths in whole milk powder, low fat milk powder and skim milk powder were all 4 mm at least when the laser intensity was 8 W and the exposure time was 1 000 ms. The Raman signal through the skim milk powder layer was weaker than those through the whole milk powder layer and the low fat milk powder layer at the same thickness. Therefore, the light penetration depth of the skim milk powder layer was less than those of the whole milk powder layer and the low fat milk powder layer. The results provide a useful reference for the pretreatment of milk powder in safety and quality detection by Raman hyperspectral imaging.

The study investigated the algae growth and lipid change by using confocal Raman microscope, and the Raman spectra were obtained from the Chlorella pyrenoidosa growing under three nitrogen conditions (nitrogen deficiency, normal and excess). Bubble diagrams of the ratio of lipid characteristic peak were presented as an intuitive expression of lipid accumulation, which was corresponding to the NR fluorescence image in some way. The preprocessed Raman signals were analyzed by using principal components analysis. Linear discriminant analysis (LDA) was used to establish a classification model by using appropriate principal component variables. The prediction accuracy obtained from LDA prediction model established by the three nitrogen conditions were 80%, 93.3% and 86.7%, respectively. The LDA classification model was established by lipid-related Raman shift (RS) at the three nitrogen conditions, and its prediction accuracy reached to 86.7%. The results showed that the identification of different nitrogen stress on microalgae grown using Raman technology was feasible, and with time passing by, the difference in the accumulation of lipid became greater.

As a new type of nanomaterials, fluorescent gold nanoclusters are low toxicity, good light stability, and long Storck shift. Based on these excellent properties, they are potentially applied as fluorescence sensors with less interference. These materials have attracted great attentions in the area of environment monitoring. However, due to the high cost and complicated reaction conditions, most methods for synthesizing gold nanoclusters are expensive and are not suitable for wide application. In consideration of the current requirement for more efficient methods for the preparation of fluorescent gold nanoclusters, egg white protein was obtained from market and employed as a green ligand for the synthesis of gold nanoclusters without the utilization of complicated procedures. The nanoclusters could be obtained at 37 ℃ through water bath for 24 h. The procedure was not only effective but also low toxicity during the synthesis process. After the synthesis, highly bright fluorescent gold nanoclusters were obtained. Based on our experiment, the As prepared gold nanoclusters had excellent stability and fluorescence properties. The excitation wavelength for the maximum emission was 470 nm and the wavelength for the emission was 680 nm with a quantum yield of 8.76%. It could be concluded that typical red emitted gold nanoclusters were synthesized, which was favorable for the environment analysis. After further investigation, the As prepared gold nanoclusters could be designed as Hg2+ selective sensor in water solution with little interference. Since the fluorescence could be quenched in the presence of Hg2+ with low concentration, it could be used for the determination of tracing amounts of Hg2+ in polluted water. The detection limit was smaller than 1 ppb, which met the requirement for the determination of Hg2+ for safe drinking water. The relative linear correlation coefficient value for the calibration was larger than 99.8%. Meanwhile, the recovery efficiency for the determination of Hg2+ was investigated. After the comparison with atomic absorption spectroscopy method, it could be concluded that the current method showed advantages for determination of tracing amounts of Hg2+. At the same time, the accuracy was satisfied for the detection of relative high concentration of Hg2+. By the employment of this method, an effective strategy can be expected for the determination of Hg2+ in natural water.

In southern Jiangsu, it’s imperative to reinforce management of the textile wastewater treatment and discharge due to a large amount of textile wastewater generated by thousands of dyeing and printing enterprises. Compared with traditional indexes of organic pollution such as chemical oxygen demand and biochemical oxygen demand, fluorescence excitation-emission matrix, which has an advantage of fast measure and high sensitivity, could exhibit organic composition in water/wastewater. In this study, the effluents reaching the discharge standards from five different dyeing and printing wastewater treatment plants in southern Jiangsu were collected. TOC, UV254 and fluorescence excitation-emission matrix were used to characterize dissolved organic matters in the treated textile effluents. The results showed that the effluents with UVA254 by TOC ranging from 1.42 to 4.29 L·mg-1·m-1 had a similar aromaticity with the effluents from the sewage treatment plants. Despite of some visional differences between excitation emission matrixes of all effluent samples, there were two major peaks locating at the excitation/emission wavelength of around 230/340 and 275/320 nm. The fluorescence intensity of the treated textile effluents after Raman calibration was much higher than that of treated municipal wastewater while that of humification index was much smaller, which indicated that non-humic aromatic compounds accounted for a much larger proportion in treated textile effluent than treated municipal wastewater. Some commonly used dyes were collected from dyeing and printing enterprises and their fluorescence excitation-emission matrix was measured. Thus, the strong fluorescence signals of treated textile effluents could be derived from the residual dyes and their incomplete degradation products. This indicated that the effluents of the dyeing and printing wastewater treatment plants might have some negative environmental impact although it reached the discharge standards. Fluorescence excitation-emission matrix could be a promising tool to exhibit the organic components in water.

A new strategy was proposed in this work to meet the urgent needs of the rapid discrimination technology of Chinese liquor brands. The ultraviolet spectra were used as the inputs, the moving window correlation coefficient was applied as the analytical method, and the Haizhilan spirit was used as the research object. The results showed that the quality of different batches of Haizhilan spirit was consistent in the experimental wavelength interval. The correlation coefficient of ultraviolet spectral original data and the moving window correlation coefficient spectral were all above 0.99. The processing techniques and raw materials of Haizhilan spirit and the other series of Yanghe spirits belonging to the same company had a higher similarity. It was difficult to quantitatively discriminate their brands only by using the ultraviolet spectral original data with correlation coefficient method. The moving window method could effectively improve the spectral detail differences, highlight the shape, intensity and trend differences of the spectral feature bands, so it could enhance the ability of the experimental spectra to identify and analyze the fine structure. After an overall investigation, the moving window correlation coefficient combined with ultraviolet feature spectra (270~295 nm) improved the differences among Yanghe spirits, and then Haizhilan spirit could be discriminated from the other Yanghe spirits with high similarities. Six brands of Chinese liquor and ethanol as the control groups were used to further demonstrate the feasibility of this approach. The innovation of this work is to propose a novel analytical idea for rapid identification of the Chinese liquor brands based on the moving window correlation coefficient spectral method. This method also has the advantages of rapidity, simplicity, and has a great potential in the quality and safety discrimination of other foods.

Sodium caseinate, as a good emulsifier and emulsifying stabilizer, plays an important role in the quality of milk beverage. Sucrose as the sweetener, can improve the taste of milk beverage. But the structure and property of casein can easily be influenced by the micro environment. To analyze the effect of sucrose on the structure and emulsification of sodium caseinate, changes of fluorescence spectra and surface hydrophobicity of sodium caseinate were investigated by fluorescence spectrum. Changes of sodium caseinate emulsion droplet hydrodynamic diameters were determined by dynamic laser scattering. Backscattering profiles and stability index (TSI) were evaluated by turbiscan spectroscopy stability analysis. The results showed that the interaction between sucrose and sodium caseinate resulted in the endogenous fluorescence quenching of sodium caseinate (KS＜2.0×1010 L·mol-1·s-1), which belongs to a dynamic quenching mechanism. The strength between sucrose and sodium caseinate was hydrogen bonding and hydrophobic interaction. Surface hydrophobicity of sodium caseinate significantly was enhanced (p<0.05), leading to the increasing in the degree of sodium caseinate aggregation and the formation of the soluble aggregates. With increasing of sucrose concentration, the emulsion droplet size stabled by sodium caseinate increased, resulting from protein aggregates preferred to adsorb on the oil-water interface under high pressure homogeneous. The backscattering profiles of sodium caseinate emulsions showed that the emulsions stability increased with the increasing of sucrose concentration. The instability phenomenon (such as stratification, concentration change, and emulsion droplet transfer) is more difficult to happen. Stability index significantly increased (p<0.05) also with the increasing of sucrose concentration. The emulsion stability increased by sucrose.

Pharmaceutical vial’s oxygen concentration detection based on wavelength modulation spectroscopy (WMS) was conducted on a single, short optical path in the open. The oxygen absorption lines at 760.885 nm (13 142.58 cm-1 ) were chosen- and the system parameters were optimized. Then, data processing method and steps were explained, such as real-time background deduction and real-time spectrum correction. Seven samples of the different oxygen concentrations were tested, and the corresponding second harmonic signals were obtained. Finally, the linear regression equations were established between the concentration and the peak height(C—H), the peak area at half maximum(C—A). The experimental results indicated that the fitting coefficients of two methods were 0.996 6 and 0.997 8, respectively, and the latter was increased by 0.12 % than the former. Prediction accuracy of the model was evaluated by fully interactive authentication method and the results indicated that the root mean square errors of prediction (RMSEP) were 0.003 1 and 0.002 0, respectively, and the latter was reduced by 37.69% than the former. The 2f signal of sample ( 4%) were severally measured for 20 times by the two methods in different time and the results indicated that standard deviations were 0.002 2 and 0.001 6, respectively, and the latter was reduced by 27.3% than the former. Meanwhile, the resolutions were 0.198% and 0.097%, respectively, and the latter was increased by 51% than the former. The system is feasible to measure the pharmaceutical vial’s oxygen concentration, and the accuracy and stability of the system can be improved by the C—A method.

The topochemistry of lignin in commercial rattan (Daemonorops margaritae (Hance)) cell wall was investigated by combining fluorescence confocal laser scanning microscopy and confocal Raman microscopy at cellular and sub-cellular level. Confocal fluorescence images indicated that within the stem tissues of rattan higher fluorescence intensity and thus higher lignin concentration was visualized in proto-, meta-xylem vessel, parenchyma between vascular bundles and the cell corner middle lamella regions of fiber. More importantly, linear unmixing images based on the difference of fluorescence spectra revealed that the Rattan fiber secondary wall was divided into alternations alternating broad and narrow layers and the lignin concentration was higher in the narrow layers. Comparing the average Raman spectra extracted from the D. margaritae (Hance), P. heterocycla cv pubescens, M. sinensis, P. tomentosa and P. bungeana Zucc. secondary wall indicated that rattan fiber wall had a comparable molecular structure as hardwood poplar. Raman images by calculating the lignin band at 1 598 cm-1further confirmed the heterogeneous distribution of lignin at cellular level. It was found that the cell corner middle lamella of fiber had the highest lignin concentration followed by the narrow layer, and had the fewest in the broad layer, which was in accordance with the topochemical features of bamboo fiber. Meanwhile, Raman spectra analysis confirmed that other than the variation in lignin concentration between the broad and narrow layers, they also displayed differences in ratio of lignin structure units. Specifically, the ratio of G lignin to S lignin was 0.19 and 0.14 in the narrow and broad layers, respectively. The present results will provide a theoretical instruction for rattan cell wall biosynthesis and the origin of cell wall reaction stress.

The automatic recognition of the peak point of the PPG signal is directly related to the accuracy of non-invasive measurement of blood oxygen saturation and the extraction of PP intervals. In this paper, a combined wavelet processing method was proposed. Based on the principle of wavelet multi-resolution analysis, the proposed method corrected the baseline wander which would influence the peak amplitude, and then the peak was identified automatically by using the quadratic spline wavelet modulus maximum algorithm. Using the signals acquired by a self-developed pulse oxygen saturation detecting device to evaluate the effectiveness, the method could correct the baseline wander and identified the peak points of the signal, and to evaluate the stability and reliability of the method, we used a noisy signal. Furthermore, by using ten segments of the measured PPG signals, we compared the peak recognition accuracy of the proposed method with that of a traditional differential threshold method to validate the effectiveness. The results showed that the method not only eliminated the baseline wander, but also could accurately detect the peak of the noisy signal, which had a good anti-jamming capability, and was beneficial to improve the detection of blood oxygen saturation and the accuracy of PP interval extraction. Furthermore, it was helpful to the evaluation of respiratory function and heart rate variability analysis.

In this work, Zinc tetraphenyl porphyrin (ZnTPP) films and ZnTPP-carbon nanotube (CNT) composite films were successfully prepered by spray coating. The morphologies, electrical and optical properties of the as-prepared materials were systematically investigated by metalloscope, scanning electron microscopy (SEM), profilometer, resistance meter, UV-Vis, and Fourier transform infrared spectroscopy (FTIR), respectively. Results revealed that the THz fingerprint peaks of ZnTPP at 44, 57, 77, 88, 95 and 102 cm-1 were similar with those of chlorophyll in palm leaves (Ref. [3]). Importantly, not only the uniformity and compactness of the ZnTPP films, but also their electrical conductivity and optical responses in a broad area from ultraviolet to terahertz were significantly enhanced after the addition of CNTs to ZnTPP. Moreover, new THz absorption peaks at 47 and 66 cm-1 were detected after the composite formation, suggesting strong interactions between ZnTPP and CNTs which led to the improvement of the comprehensive properties of the composite films. These results demonstrate that the electrical and optical properties of ZnTPP can be effectively modified by CNTs, and by which the comprehensive properties can be achieved, thus, the requirements of optoelectronic devices can be met. The results in this work will be helpful for promoting the study on the terahertz spectra of the organics as well as seeking new terahertz organic sensitive materials in the future.

In this paper, Normal Raman Scattering (NRS) spectroscopy of o-hydroxybenzoic acid (OHBA) and Surface-enhanced Raman Scattering (SERS) spectroscopy of OHBA adsorbed on gold nanoparticles were studied. The spherical gold nanoparticles were prepared by chemical reduction method with gold chloride acid as precursor and trisodium citrate as reductant. The NRS spectroscopy of OHBA and the SERS spectroscopy of OHBA adsorbed on gold nanoparticles were collected by laser Raman spectrometer, and the laser beam (785nm) was used as the excitation light source. Meanwhile, density functional theory (DFT) method at the B3LYP/6-31+G**(C, H, O)/LANL2DZ(Au) level was used to optimize molecular configurations of o-hydroxybenzoic acid. Base on the optimized structure, the NRS spectroscopy of OHBA and the SERS spectroscopy by different adsorption configurations of OHBA adsorbed on gold nanoparticles were all calculated. Compared with the experimental data, the results showed that the calculation results using OHBA molecular adsorption configuration through carboxyl were much more matched with the experimental values than those of using OHBA molecules adsorption configurations through hydroxyl. At the end, comprehensive assignments of the vibration mode for OHBA were studied by GaussView. According to the identification analysis of OHBA molecular Raman peaks, it could be drawn that, in gold colloids, the OHBA molecule would be tipsily adsorbed on the surface of gold nanoparticles through the carboxyl. The visualization software displayed the structure characteristics and molecular group vibration of this molecular and provided important basis for assigning the vibrational peaks. This work has important effect on the further applications of o-hydroxybenzoic acid in biomedicine and other fields.

Heat treatment is an environmentally friendly method which can improve the decay resistance and dimensional stability of wood. In this study, in order to investigate the effects of thermo-vacuum treatment on dynamic water vapour sorption and chemical properties of larch wood, wood samples were treated at 200 ℃ in a vacuum oven for different durations. The changes of wood hygroscopicity before and after heat treatment were characterized by dynamic water vapour sorption. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopic (XPS) and X-ray diffraction were used to characterize the changes in the chemical composition. The results showed that the equilibrium moisture content of wood decreased as the treatment time increased. FTIR and XPS found that the chemical composition of wood such as cellulose and hemicellulose degraded after heat treatment and the crosslinking condensation reaction of lignin occurred resulting in the decrease of the content of hygroscopic group. During heat treatment, the contents of carbon and oxygen changed and O/C ratio decreased. Besides, changes were also identified from the detailed C(1s) spectra. The C1 content of heat treated wood increased, and the C2 and C3 contents decreased. These chemical changes reduced the hygroscopicity of the heat treated wood. The relative crystallinity of wood increased with the increase of heat treatment time. The increase of the crystallinity decreased the number of water-absorbing groups on the cellulose chain, which decreased the hygroscopicity of wood.

The P(4) line of 3-0 band for CO gas in different pressures and concentrations was measured by employing tunable diode laser absorption spectroscopy combined with balanced difference detection technology. Due to the immunization to the common-mode noise of fluctuation of laser intensity, drifts of temperature and mechanical vibrations, the sensitivity of spectroscopy can be improved by balanced difference detection technology. In comparison with the direct absorption spectroscopy (DAS), the signal to noise ratio was improved by 3.4 times, and the minimum detection limit (MDL) reached 87 ppmv. The optimum pressure for CO was 70 Torr through comparing the spectral signals at 40 Torr, 55 Torr, 70 Torr and 85 Torr of 1% CO concentration. Moreover, different concentrations of CO at 70 Torr were detected by DAS and balanced difference detection, and the results demonstrated the balanced difference detection had a more linear relationship and the deviation was less than 5%. For further testification of the stability of the system, we collected the signals within 360 s for the Allan variance analysis, which denoted the most suitable detection time was 38 s and the MDL was 47.8 ppmv.

Volatile chlorobenzenes (CBs) is an organic pollutant which exists ubiquitously in the environment. Ion Mobility Spectrometry (IMS) has been a powerful technique for quick ion-separation and detection under ambient pressure. In this paper, atmospheric chlorobenzene, p-dichlorobenzene, o-dichlorobenzene and m-dichlorobenzene were detected by a homemade Vacuum Ultraviolet Field Asymmetric Waveform Ion Mobility Spectrometry (UV-FAIMS). The CV-I spectra under different Dispersion Voltage (DV) were obtained, then the CV-DV fingerprints spectra of the four substances were synthetized. Base on the fingerprint spectra, optimal separation and detection parameters of three isomers: dichlorobenzene, o-dichlorobenzene, m-dichlorobenzene were determined. The results showed that under the DV of 800 and 1 000 V, three substances could be effectively identified at CV of 20.4 V (DV=800 V), 3.2 V(DV=800 V) and 11.9 V(DV=1 000 V), respectively, by selecting the characteristic peaks. The influences of flow rate on FWHM and peak position of FAIMS spectrum were studied and the results provided a reference for flow optimization. The limit of detection (LOD) of UV-FAIMS investigated by using different concentrations of dichlorobenzene at DV=450 V and CV=4.3V was lower than 0.05 mg·m-3. This paper provides a rapid and accurate detection method for halogenated benzene pollutant and other isomers of benzene.

The surface damage and soluble solid content were detected simultaneously in online grading of yellow peach, and the damage level and soluble solid content are the important criteria for evaluating the quality of yellow peach. Hyperspectral imaging technology was used to detect the damage level and soluble solid content of yellow peach simultaneously. The principal component analysis was used to obtain the best PC image firstly. Then according to the contribution rate of characteristic wavelength to PC image, the best wavelength of the image (550 and 720 nm) was determined. In the last, the binaryzation, image masking, threshold segmentation and the related image processing technology were combined to qualitatively discriminate the spectral images corresponding to the best characteristic wavelength. Its accuracy was up to 92.9%. At the same time, partial least squares regression model was established to predict the SSC content of normal samples, and by the continuous optimization of the model, online simultaneous detection of yellow peach bruise and soluble solids based on the hyperspectral imaging technology was finally realized. The sorting accuracy of soluble solids was 79.2%. The experimental results show that the yellow peach bruise and SSC can be detected on-line simultaneously by using hyperspectral imaging technology. This research can provide references and basis for the online sorting.

With the development of spectral imaging technology, the images with high spatial resolution and high spectral resolution acquired greatly improves the recognition ability of ground objects. In order to quickly and accurately obtain the 2D spatial image information and the 1D spectral information of the targets, a hyperspectral imaging system based on an acoustic optic tunable filter (AOTF) was designed. Due to the limitation of the polarizer extinction ratio, the 0 level light outside the field overlapped with the +1 diffraction of the measured target, and the image could be an image with 0 level interference approximately when the AOTF was not driven. In this paper, a method of 0 level interference suppression for AOTF adding driven imaging and removing AOTF no driven imaging was proposed, and the system prototype was used to carry out the field spectral imaging experiment. The results were modified by interference suppression method of 0 levels. The experimental correction results indicated that this method not only greatly eliminated the interference of the 0 level, but also improved the measurement accuracy of the imaging spectrum.

Anthocyanin has the antioxidant effect, which is helpful to the recover of leaf injury. The dynamic change of anthocyanin concentration can be considered as a sensitive indicator to reflect plant physiological conditions affected by external environmental stresses, consequently the anthocyanin content of mosaic virus infecting apple leaves can be used as an important criterion for assessing the degree of disease. In this research, hyperspectral images of apple leaves with mosaic disease were acquired by imaging spectrometer. By the combination of each two bands, spectral reflectance was used to establish the optimal spectral indexes which were highly correlated to the anthocyanin content in infected leaves. Further more, a accurate anthocyanin concentration estimation model was established taking these spectral indexes as parameters. The results were as follows: (1) The damage of mesophyll cells in mosaic virus infecting apple leaves would cause the increase of anthocyanin content. As a result, the spectral reflectance of infected area increased significantly in visible region, while in near infrared region the reflectance was lower than the normal. In addition, the red-edge position shifted to the shorter wavelength and both the red-edge area and the first derivative spectral reflectance at red-edge position decreased. (2) The correlation between leaf anthocyanin content and spectral reflectance was extremely significant at most of the wavebands and reached the peak at 581 nm. The normalised deviation spectral index combined with spectral reflectance at 770 and 722 nm, the simple ratio spectral index combined with spectral reflectance at 717 and 770 nm and the deviation spectral index correlated with spectral reflectance at 581 and 520 nm were all significantly related to leaf anthocyanin content, with the correlation coefficent of 0.838, 0.865 and 0.875, respectively. (3) Anth-PLSR was the optimal model to estimate apple leaf anthocyanin content, of which the determination coefficient was 0.823 and RMSE was 0.056. The anthocyanin content distribution diagram of leaves were made by solving the hyperspectral images pixel using Anth-PLSR model, thus the anthocyanin content of an integral leaf was calculated. On the other hand, by extracting the average spectral reflectance from the the hyperspectral image of a whole leaf, the anthocyanin content of the integral leaf can be obtained using Anth-PLSR model. The results of these two different methods showed a high consistence by fitting analysis, which demonstrated that the latter method could be used to rapidly detect the anthocyanin content of apple leaves.

Rape aphids can reduce the production and quality of rapeseed seriously, so early discrimination of the rape aphids and identification of the infection location are helpful for precisely spraying pesticide. In this study, hyperspectral imaging in visible and near-infrared region combined with imaging processing were employed to discriminate the healthy and aphid infected rape pods, as well as identify the location of rape aphids. Here, a total of 323 samples covering 138 healthy and 185 aphid-infected rape pods was investigated. Firstly, principal component analysis (PCA) was used to conduct the cluster analysis of the two groups rape pods, and the wavelength at 737 nm selected by X-loading was considered as an important waveband for the purpose of aphid discrimination. Then, statistical analysis of spectral data from the two groups’ samples at single band (737 nm) was finished by boxplot. At the same time, a linear equation y=2.917 6-3.345 7x (x represented the spectral data of 737 nm, y denoted the predicted dummy classes) was obtained based on above analysis. Relying on the linear equation, discriminant analysis was carried out for the 323 samples and the recognition accuracy reached 99.0%. Next, the location of rape pods was identified based on the single band grayscale images. For the infected rape pods, the method led to an overall detection accuracy of 81.1%. The results revealed that the spectral data at 737 nm and its image information is a promising tool for identifying the location of aphids in rape pods, which could provide a theoretical reference and basis for designing the handheld detection system and the precise spraying of rape industry in the further work.

Online accurate proximate analysis of coal is vitally important to the optimization of industrial production and reduction in coal consumption. However, due to the “matrix effect” caused by the complex and diverse coal species in China, the measurement accuracy needs to be improved by using laser-induced breakdown spectroscopy (LIBS). In our experiment, both the spectral pretreatment method and the calibration model for the conversion of laser induced coal plasma spectra to the coal proximate analysis results were optimized. Experimental results showed that, compared with the traditional method, the proposed single- or multiple-peak Lorentzian spectral fitting for spectral line intensity calculation reduced the mean RSD from 12.1% to 9.7%. For kernel function parameters optimization, the mean absolute error (MAE) of the particle swarm optimization (PSO) was smaller than that of the grid parameter (Grid) and the genetic algorithm (GA). The root mean square error (RMSEP) of support vector machine (SVM) regression model based on PSO parameter optimization was less than that of partial least squares regression (PLS). By combining the single- or multiple-peak Lorentzian spectral fitting method with the PSO based SVM for regression modeling, the average absolute errors (AAE) of predicted proximate analysis results were certified to be: 1.37% for coal ash content of 16%~30%, 1.77% for coal ash content of 30% or more, 0.65 MJ·kg-1 for calorific value of 9~24 MJ·kg-1, 1.09% for volatile matter of 20% or less, and 1.02% for volatile matter of 20% or more.

Laser induced breakdown spectroscopy with long-pulse laser(500 μs) was used to generate plasma of soil sample in air. The spectroscopy emission characteristic of soil plasma was investigated under the low power-density conditions. Intense continuum background could not be detected (402~409 and 420~436 nm) and the long-pulse laser induced plasma had a longer overall life time (about 220~270 μs), which was different from the dynamic characteristics using nanosecond laser and ultra-short pulse laser. Besides, the spectral lines of Pb Ⅰ405.78 nm and Cr Ⅰ425.43 nm appeared at about 210 and 190 μs. Intensity of Pb Ⅰ405.78 nm and Cr Ⅰ425.43 nm increased as time passed by, reaching to its maximum at 320 and 350 μs, respectively. The study results showed that increased interaction time between laser and sample contributed to the formation of “quasi-stable state plasma”. The relative standard deviation was 2.21%~6.35% concluded by 8 times repeated experiments, which showed a better stability of soil plasma by using a long-pulse laser. The detection limits of Pb and Cr were 34.7 and 40.0 mg·kg-1, respectively, which was below the trace element thresholds for Class 1 soil used in the environmental quality standard in China. Parameters characterizing a laser-induced plasma were obtained with the temperature of 6612 K and electron density of 3.7×1017 cm-3 in the condition of long-pulse laser. Experimental results showed that it was in local thermodynamic equilibrium.

In recent years, solution cathode glow discharge atomic emission spectroscopy (SCGD-AES), a booming technique for metal element determination in aqueous solution, has a large quantity of notable characteristics, such as working under atmospheric pressure, easy simple injection, little size, small volume, low operating costs, and simultaneous detection of multi-metal-elements. According to our previous researches, the concentration of metal elements was relative to not only one of its characteristic spectral lines, but also the other characteristic spectral lines of itself or the characteristic spectral lines of other elements. In order to improve the detection capability and accuracy of solution cathode glow discharge atomic emission spectroscopy, reduce the matrix effect in the complex solution and make full use of spectral information, the multivariate linear regression method was employed to make a quantitative analysis of spectral information. Two characteristic spectral lines of Pb Ⅰ 368.35 nm and Pb Ⅰ 405.78 nm were employed to establish the binary linear regression equation; compared with standard curve method, the degree of fitting R2 increased to 0.998 7 from 0.986 5, and the relative errors of two test solutions decreased to 14.20% and 1.51% from 34.00% and 29.00%, respectively. Quaternary linear regression equation using Na Ⅰ 589.38 nm, Zn Ⅰ 213.80 nm, Pb Ⅰ 405.78 nm and Hβ were also built to reduce the matrix effect in the complex solution; compared with standard curve method, the degree of fitting R2 increased to 0.995 6 from 0.955 8, and the relative errors of two test solutions decreased to 2.33% and 3.57% from 11.67% and 14.71%, respectively. The above results indicate that: compared with standard curve method, multivariate linear regression method has the ability to reduce the influence of matrix effect in the complex aqueous solution, take full advantage of spectral information, improve degree of fitting (R2)and reduce the errors, thus improve the accuracy of metal elements determination with solution cathode glow discharge atomic emission spectroscopy.

The rapid detection and real-time monitoring of plant elements is very important in the field of agriculture. A method using Laser Induced Breakdown Spectroscopy (LIBS) for the determination of the spectroscopy characteristics of Cu in tobacco was evaluated. To perform the calibration curve, several tobacco samples containing Cu arranged from 8.59 to 156.35 μg·g-1 were prepared. The amount of Cu prepared in laboratory was measured using atomic absorption spectroscopy. Experiments indicated that the characteristic spectrum of Cu at the wavelength of 324.75 nm was quite clear, and easy to obtain. From the characteristic spectra obtained from Cu-contained samples, the temperature and density of the plasma induced by laser were calculated to be 39 458.94 K and 0.74×1016, respectively. The fitting curve between the intensity of the spectral lines and the sample concentrations was established with the correlation coefficient (r square) of 0.98 , the mean relative standard deviation (RSD) of 2.59%, the limit of detection (LOD) of 7.72 μg·g-1 and the spectral signal-noise ratio of 7.86. The method was successfully applied to predict the Cu amounts in tobacco samples, which has a potential to be used in cigarette production lines and tobacco breeding.

Coal is a kind of sedimentary organic rock with the feature of microcrystalline and crystalloid structure in long-range disorderly and short-range orderly. As coalfication degree increases, coal structure grows more regular. In the coal-forming process, coal body has deformed in different degree due to the destruction of geological structures, and thus the chemical composition and microcrystalline structure of coal have been changed, which have made tectonic coal with different coal body structure formed. In order to study on change law of the microcrystalline structure of coal under geologic structure, the paper is exampled by two kinds of coal with different rank, that is gas coal and lean coal, and investigated on the differences in microcrystalline structure for coal samples with different deformed degree before and after solvent extraction. By means of X-ray diffraction (XRD), the microcrystalline structures of coal samples and their residues were measured. The results show that the solvent extraction rate appear a post relationship with the degree of coal body structure, and the contrasts of the extraction between different deformed coal samples do not alter with the change of solvent species and coal ranks. Meanwhile, under room temperature conditions, the solvent extraction is not enough to alter the contrast relationships of microcrystalline structure parameters between high and low rank coal . The value of aromatic lamellae spacing (d002) of lean coal is less than gas coal, and stck high (Lc) and layer numbers (N) is more than gas coal. Further study indicates that the value of d002 decreases and Lc increases under the tectonic damaging effects. But the value of the diameter (La) does not show obvious regularity at the influence of coal ranks, solvent species and infiltration degree.

Determination of inorganic elements in traditional Chinese medicine by conventional wet-chemistry approach is complex and time-consuming. The samples must be digested before instrumental analysis. For preparations containing cinnabaris or realgar, high content of Hg and As will contaminate lab wares and instruments. However, X-ray fluorescence spectrometry is simple, fast and can simultaneously determine multiple elements in a non-destructive way. In this paper, portable X-ray fluorescence spectrometry was applied to establish a novel method for rapid and nondestructive determination of Hg and As in Niuhuang Qingxin Pills. And the method was employed in homogeneity analysis of the drug for the first time. After optimization of the measurement mode, using the inductively coupled plasma-optical emission spectroscopy as the reference value, working calibration curve was obtained for determination. Experiments results showed that precision was high with relative standard deviation of 0.09% and 0.23%, respectively, and the determination results of Hg and As were close to the reference values with relative mean deviations of 8.58% and 5.95%, respectively, which met the requirements of on-site rapid screening. Results indicated that contents of Hg in 2 batches of the samples were abnormally low and contents of As in 1 batches of the samples was abnormally high. Sample from 1 manufacturer was inhomogeneous. The proposed method was quick, simple, economic and environment-friendly, which offered a new approach for quality control of traditional Chinese medicine containing mineral. The portable instrument brings high efficiency and high throughput, which can help revealing hidden danger of drug quality. In all, X-ray fluorescence spectrometry can save time, manpower and resources, and has a bright prospect in application.

A pair of hand carved sandstone lions produced in Qin Dynasty lie in the front of the government site of Chongqing city covered by a layer of black crust with missing parts, and cocked or curly edges. To explore the structural and compositional properties of the black crusts and reveal its influence on the surface of stone sculpture, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectrum (XPS) were applied to analyze the samples of black crust and stone base. The conclusion indicated that the black crust was originated from the weathering of prior protective coating including three chief layers: the undercoat, the intermediate coat (mixed by CaSO4 and ZnS) and topcoat observed by elemental Mapping. Among them, the black crust was chiefly attributed to a discolored process from white basic lead carbonate ［(2PbCO3·Pb(OH)2)］ to black galena (PbS), and the carbonization of organic material in the protective coating. The strong —OH peak identified by both FTIR and XPS analysis on the black crust demonstrated an increasing tendency of —OH in the carbonization of the protective coating which made it more hydrophilic and easy to swell when it is damp and shrink when it is dry, so as to cause a large area of peeling, cocking and curling. Most importantly, water would be detained in those spaces between black crusts and the surface of sandstone which could accumulate the corrosion resulting in some damages on the carved sculpture. For example, a high concentration of anhydrite (CaSO4) was detected by SEM/EDAX and XRD in the back of black crust and the surface of sandstone, which can be transformed into gypsum by hydration with volume expansion causing the pulverization of sandstone. Therefore, when encountered with the aged protective coating on the outdoor stone cultural relics, it is important to remove them timely avoiding the further corrosion in the micro spaces between black crusts and the below sandstone.

For the technology requirements of appreciating mural paintings, according to the advantages of spectral imaging and spectral analysis, the usages of spectral imaging in appreciating mural paintings were discussed, which could improve the traditional expert experience identification method by providing more information in the appreciation and assessment. Spectral method is an important scientific analysis method with many characteristics, like non-contact, lossless, scientific, accurate and quantifiable, which can be used to appreciate mural paintings. Firstly, the application was analyzed from different functions. Secondly, the measurements of mural paintings in HAN XIU tomb were processed by spectral analysis, primary component analysis, independent component analysis, relevance judgment and interactive processing, which were for proving the real affection of the theory analysis. At last, based on the experiments, some key technologies were summarized, for example, normalized measurements, analysis of characters of image and spectral data, processer of image and spectral data. The experiment results showed that the spectral imaging and analysis were useful for the recognition of pigment, the extraction of hidden information, the enhancement of weak information, and the classification and recognition of different properties. Meanwhile, some exploratory works can be unfolded, like modified child analysis, repairing of paintings (such as repairing mural paintings in HAN XIU tomb).

Under the impetus of extraterrestrial solar spectral irradiance measurement and atmospheric quantitative remote sensing, spectroradiometry technology makes a rapid progress internationally in recent years. Based on the advanced high temperature technology, excellent pyrolytic graphite materials and unique designs, All-Russian Research Institute for Optical Physical Measurements (VNIIOFI) successfully developed large area Planck high temperature blackbody sources with temperature as high as 3 200~3 500 K which had the high uniform and high stable radiation characteristics. By means of filter radiometer calibrated by absolute cryogenic radiometer (ACR), the new iteration temperature measurement technology of high temperature blackbodies made the temperature uncertainty less than 0.5 K. At PTB, high temperature blackbody was directly used for the calibration of solar spectral irradiance measurement instruments, SOLSPEC, on board International Space Station and the uncertainty of calibration was less than 0.5%~1%. The new generation electron storage ring Metrology Light Source (MLS) was set up at PTB in 2008. The electron energy for stable ring operation could be set to any value from 105 to 630 MeV, giving a high flexibility in adjusting the SR spectrum. Through this operation, the characteristic wavelength of the radiation emission could be shifted from 735 nm to 3.4 nm. In order to change the synchrotron light intensity without changing the spectrum, the electron beam current could be adjusted within a range of more than 11 decades, i.e. from one stored electron which was equivalent to the current of 1 pA to the design value of 200 mA. At NIST, the FICUS (Facility for Irradiance Calibration Using Synchrotron) was built on beamline 3 at SURFⅢ (Synchrotron Ultraviolet Radiation Facility) using for the calibration of ultraviolet spectral irradiance transfer standard deuterium lamp. The uncertainty of the 200nm-400nm spectral irradiance was 1.2% (k=2). The new generation synchrotron radiation facilities laid the technical foundations for the high precision calibration of solar spectral irradiance measurement instruments in short wavelength such as SBUV, SUSIM, SOLSTICE, SIM and SOLSPEC. This paper described the establishment and development of the new generation high temperature blackbody and synchrotron radiation facilities, spectral radiance standard and spectral irradiance standard transfer and international comparison, and reviewed their application in solar spectral irradiance measurements.

Confocal Raman technique, which combines confocal microscopy and Raman spectroscopy techniques, plays an important role in the field of physical science, material science, biomedical and cultural relics identification, criminal investigation with high resolution, high sensitivity, and the advantages of tomography. The existing commercial confocal Raman spectrometers have no fixed focus ability so that the sample table drift caused by defocus often appears in the measurement, which affects the measurement results. In view of this problem, a laser confocal Raman spectroscopy detection system with anti-drift capability was developed in this paper. Based on the confocal Raman detection principle, this system could realize auto focus by using Raman axial response curve of the maximum confocal position of the corresponding samples. The spectral intensity extremum position was obtained by curve fitting, and it realized the real-time location of measured samples at the confocal position to improve the effect of Raman spectral imaging. In this paper, we used the single layer graphene samples for single point test and the auto focus could be realized in 5 μm, and the intensity we got has almost no changes. We can say the system has a better ability of anti-drift. We got Raman imaging of silicon step samples. We could find that it had stable single and better lateral resolution, which was obviously superior to the conventional confocal Raman spectrum detection system in long time measurement.

The movable mirror is used to distinguish optical path difference in a continuous scanning FTIR. Moving mirror scanning system is the only moving part in FTS, the accuracy of scan and the distance of scan, would affect the signal to noise ratio (SNR), repeatability and resolution of the instrument directly. A moving mirror scanning system that based on flex cross-spring pivots were designed, and a fuzzy controller was designed to ensure that the movement of the moving mirror system is collimated, uniform and smooth,with the control accuracy up to 99.8%.

In order to detect soluble solids content(SSC) in fruit conveniently and rapidly, a portable soluble solids content spectrometer for apple was designed based on STS spectrometer. The NIR spectral data were obtained by the portable fruit soluble solids content spectrometer and recorded with the integration time of 100 ms in the wavelength range of 630~1 125 nm. Meanwhile, two structural parameters light source angle α and distance between light source and probe W were analyzed for investigating the influence of the response properties of visible-NIR spectra. The partial least square regression model and least squares support vector machine model were established. By comparison, partial least square regression model performed better. When the distance between probe and light source was 15 mm and the angle of light source was 45, its performance was the best with the root mean square error(RMSEP) of prediction set of 0.334% and correlation coefficient of prediction set of 0.924.

Laser Induced Breakdown Spectroscopic (LIBS) technique was used to detect calcium and silicon in an unknown sample. In this method plasma was generated by Nd∶YAG laser of wavelength 1 064 nm with energy 400 mJ and pulse duration between 5~10 ns. The method was applied for the qualitative as well as quantitative analysis. In the qualitative analysis, the electron number density (Ne) of plasma containing calcium and silicon is determined showing that Ne of neutral particles is equivalent to 1016 (cm-3) whereas for ionized particles it is 1017 (cm-3). Plasma temperature is measured using Boltzmann plot method which must be greater than 10 000 k. Intensity ratio method is used for the quantitative analysis shows various elements in abundance with calcium and silicon in majority.

The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study. Following the recorded sound signals were denoised by using wavelet filters, the signals were applied bicoherence analysis that is an high order spectral analysis method. It has been demonstrated that varieties of mitral valve pathology could be determined by three-dimensional surfaces of bicoherence and maximum bicoherence values.

Quantitative analysis of four heavy metals Pb, Cr, Cu and Cd in soils and solid wastes using independently developed portable system of laser-induced breakdown spectroscopy. A Nd: YAG pulse laser with fundamental wavelength of 1 064 nm is used as the excitation source, with the single pulse energy of 100 mJ the pulse width of 6 ns, and the operating frequency 3 Hz. The echelle spectroscopy with high resolution and wide spectral range is used as the spectral separation device, and the intensified charge coupled device (ICCD) as the spectral detection device in the experiment, with the detection range of 200~500 nm and a resolution of 0.08~0.12 nm. In order to improve the spectral intensity and detection sensitivity, a device of hemisphere spatially bound is used to restrain the plasma and a optical fiber with multi-channel is used collect the signal. The reception angle is 45°. The laser repetition rate is 2 Hz while the delay is 1.5 μs, with the gate width of 1.05 ms. Standard addition method is used to effectively solve the quantitative analysis of samples of unknown matrix. The innovation lies in the fact that, a curve fit instead of a straight line fit is used in the standard addition method to quantitative analyze the heavy metals in soils and solid wastes, which effectively improve the measurement results. Especially for the low concentrations of soil samples, linear fitting can not be used in quantitative analysis, in contrast, the correlation coefficient of curve fitting is much higher, more closer to the national standard measurement methods, to meet soil pollution detection. The result of seven soils and solid wastes samples are as follows, line fitting relative error: Pb 1.26%~79.38%, Cr -22.44%~82.06%, Cu 15.09%~190.50%, Cd 32.76%~167.96%, and curve fitting relative error respectively Pb -4.19%~11.92%, Cr -38.31%~9.26% , Cu -7.24%~26.86%, Cd -10.52%~12.94%, the average relative error is 10.47%.

Middle-infrared (MIR) spectroscopy is a well-known, rapid and non-destructive technique suitable for analyses of many different herbal medicines. In this work, MIR combined with clustering analysis was used to develop a novel method for the analysis of two kinds of Codonopsis pilosula. Altogether 49 samples were collected and analyzed. Their entire FT-IR spectra in the range of 4 000~400 cm-1 were generally similar except for small differences around 1 738 and 935 cm-1, indicating that they had similar chemical components. In the second derivative spectra (SD-IR), more distinct fingerprint features were revealed, especially peaks at 1 747, 1 515, 1 468, 1 368, 1 264, 1 163, 1 147, 1 108 and 936 cm-1. Furthermore, the 2D-IR spectra provided obvious differences of “Wen Dangshen” (WDS) and “Bai Tiao Dangshen” (BTDS). In the range of 1 510~1 170 cm-1, WDS had a strong 3×3 peak cluster, including three auto-peaks at 1 459, 1 298 and 1 209 cm-1, and the strongest auto-peak located in 1 209 cm-1. Whereas BTDS had only one very strong auto-peak at 1 450 cm-1 and three weak auto-peaks at 1 340, 1 260 and 1 209 cm-1. Moreover, the two species (49 samples) has been objectively classified with K-means pattern recognition technique. In conclusion, the three-step infrared macro-fingerprint identification method combined with K-means pattern recognition technique is simple, rapid and non-destructive, which plays an important role in discriminating similar natural products to ensure safe and effective clinical treatments.

Multispectral imaging techniques are based on the facts that each substance has a characteristic absorbance and reflectance spectrum. Besides, it takes into consideration the fact that the corresponding color biases in different monochromatic spectral ranges may be enhanced by converting the monochromatic greyscale image into a false-color image. Thus, multispectral imaging may be applied to the investigation of painting materials. It is, however, necessary to first establish a multispectral image database for archeological painting materials. Such a database would enable multispectral imaging to be used to conduct preliminary surveys on undecipherable sections of murals, pigments of similar hue, and organic materials that cannot be observed under visible light. The preliminary survey results may then be used as a basis for more detailed studies conducted using high-precision instruments. In this study, a standard pigment color chart was created using the 29 painting materials that are known to have been used in the Dunhuang murals. Reflectance and fluorescence imaging of the pigments was performed in various spectral ranges between 250 and 1 300 nm, using a standardized multispectral imaging procedure under optimized multispectral imaging conditions. The resulting data were then post-processed and combined with infrared (IR) and ultraviolet (UV) reflectance false-color images for use in the preliminary construction of a standard multispectral image database for the painting materials used in the Dunhuang murals. Multispectral imaging was then performed on actual murals to simultaneously collect visible, IR, and UV reflectance false-color images that were then compared with the standard image database. The multispectral imaging results were analyzed via comparisons with data obtained using portable microscopy, portable x-ray fluorescence spectrometry, and near-infrared spectroscopy. The results show that the establishment of a standard multispectral image database for mural painting materials can be applied as a new nondestructive analytical method. This method can be used in the preliminary verification of painting materials used in the Dunhuang murals, to identify the properties of the painting materials, and to obtain information such as pigment distributions. The establishment of this database will also increase the reliability and effectiveness of preliminary studies on the type and scope of commonly observed painting materials. Thus, it is expected to be useful in pigment studies.

The magnetic resonance spectroscopy (MRS) results are greatly influenced by reconstruction of the spectrum and quantitative analysis. Because of this requirement a number of programs dedicated to MRS data analysis were developed. The selection and use of appropriate software is crucial not only in clinical procedures, but also while carrying out scientific research. The choice of the software to suit the user’s needs should be based on the analysis of the functionality of the program. It is particularly important from the user’s viewpoint to identify what data can be loaded and processed in the program. The specific programs allow the user different degree of control over analysis parameters. Moreover, the programs for MRS data analysis differ in terms of the applied signal processing algorithms. The aim of this work, therefore, is to review available packages designed for MRS data analysis, taking into account their capabilities and limitations.

SO2-4/CeO2-TiO2 composite oxides were prepared with sol-gel and impregnation method. The structures and properties of the as-prepared samples were characterized with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), pyridine adsorption infrared spectroscopy (Py-FTIR), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Valence band X-ray photoelectron spectroscopy (VB-XPS) and photo-luminescence(PL) spectroscopy. The photocatalytic activity of the samples was tested through the reaction of the hydrogen production from water splitting. The results of XRD and FTIR and PL revealed that the heterojunctions were formed into CeO2/TiO2 phase junctions, which was conducive to promoting the separation of photo-generated electrons and holes. Py-FTIR spectra showed that Lewis acid site was formed on the surface of the SO2-4/CeO2-TiO2 composite, while formation was attributed to the SO2-4 coordinated to metals on the sample surface. The induced effect of SO led to an increase in the electron accepting ability of the surface metal ions and thereby further enhanced the separation of the photogenerated carriers. The UV-Vis and VB-XPS spectroscopy results showed that the semiconductor composites could narrow the bandgap and expend the light response range. The Lewis acidity affected the band structure of the composite oxide and made the position of conduction band minimum move to a more negative direction, which improved the photocatalytic reducibility of the catalyst and contributed to the improvement of hydrogen production activity. The results of hydrogen production from water splitting showed that the photocatalytic activity of SO2-4/CeO2-TiO2 composite oxide was better than that of pure CeO2, TiO2 and the CeO2-TiO2 composite oxide without the impregnation in sulfuric acid, and the average H2 yield rate was 1 934.1 μmol·g-1·h-1 in 5 h. The results of spectral analysis combined with photocatalytic activity of hydrogen evolution showed that the synergetic effects of heterogeneous structure of SO2-4/CeO2-TiO2 composite oxide and the acid impregnation promoted the photocatalyst activity.