Based on Mie scattering theory,we design three kinds of nanostructures (Au,Au-dielectric,dielectric-Au)and study the effects of the structure parameters and the background refractive indexes on optical scattering properties of nanostructures.It is demonstrated that by increasing the outer radius of the nanoparticle,the resonance position will show a redshift and the linewidth increases.In addition,the dipole approximation is no longer valid.Experimentally discovered that comparing with the results of the Au spherical nanoparticle,the scattering peak enhances and the linewidth becomes narrower as the increase of the core radius in Au-dielectric core-shell nanostructures under the dipole approximation.For the dielectric-Au core-shell nanostructure,it is found that when the thickness of Au layer decreases,the strong coupling between the spherical mode and the cavity mode makes the resonance peak position redshift and the scattering peak increase significantly.With the increase of the refractive index of the dielectric core or shell,the mode will be further red shifted for Au-dielectric or dielectric-Au core-shell nanoparticles.Finally,by introducing gains into the dielectric layers of the Au-dielectric core-shell nanoparticles or reducing the dielectric-Au core-shell nanoparticles in silica environment considering the practical application,the narrow-band and strong scattering in the visible range can be realized.These results will provide important theoretical basis for the fabrication of the high performance transparent display screens.

Pesticide residue is a significant problem in agriculture that greatly affects human health and life safety.Therefore,it is an urgent need to develop simple and effective method for the rapid detection of trace pesticide residue.In this work,combined with a portable Raman spectrometer,a surface-enhanced Raman spectroscopy (SERS)method was developed to achieve the rapid detection of trace organophosphorus pesticides including fenthion and parathion using gold sols as the SERS substrate.It was found that the characteristic Raman peaks of fenthion and parathion located at 1053 cm-1,1216 cm-1 and 857 cm-1,1112 cm-1,respectively,thus enabling the multi-target analysis simultaneously.The concentrations of fenthion and parathion display a linear relationship with their corresponding Raman intensities with a detection limit of fenthion can reach 0.01 μg/mL and parathion can reach 0.025 μg/mL.Furthermore,the SERS method developed here was successfully applied in the direct detection of fenthion and parathion residue on practical spinach samples with a detection limit of 0.05 μg/mL.This work demonstrates that SERS can be a convenient,rapid,sensitive and multi-target analysis method for the on-site detection of pesticide residues.

In this work,a popcorn-like Au@Ag core-shell superstructure was synthesized using dopamine dithiocarbamate (DDTC)as reducing agent to control the discontinuous overgrowth of the Ag nanoparticles onto Au nanocubes (Au NCs).The popcorn-like nanoparticles exhibited tunable plasmon resonances over a spectral range in visible regions.And the thickness of hierarchical Ag shell was finely tuned in a range from 17 to 29 nm by simply varying the concentration of AgNO3solution.Furthermore,these nanoparticles could assemble into monolayer films using liquid-liquid interface self-assembly technique,and the surface enhanced Raman spectroscopy (SERS)performances of the prepared monolayer films with different AgNO3concentration were evaluated using crystal violet (CV)as the probe molecule.Meanwhile,three different excitation laser wavelengths (532 nm,633 nm,785 nm)were employed to investigate the effect of different laser wavelengths on the SERS performance of different substrates.This work indicates that the popcorn-like Au@Ag core-shell superstructures possess tunable localized surface plasmon resonance (LSPR)and SERS properties,which enables them to have great application prospect in solar cells,catalysis,chemical sensing and other fields.

CS2 gas is not only an atmospheric odor pollutant,but also a crucial characteristic gas for fault diagnosis of Gas Insulated Switchgear.However,the temperature change in the detection environment directly affects the accuracy of the monitoring data.The paper uses CS2 gas to have noticeable characteristic absorption characteristics in the ultraviolet band.Continuous light sources and differential absorption spectroscopy techniques are utilized to monitor different concentrations of CS2 gas at different temperatures.The inversion of the CS2 gas concentration is carried out by the least squares method,and the inversion result is subjected to least squares fitting to obtain a temperature compensation formula.The experimental results show that the UV differential absorption of CS2 gas decreases with the increase of temperature into a quadratic curve,resulting in a gradual increase in concentration error.This is particularly noticeable when the gas concentration is low.The temperature compensation formula is used for the measurement of the actual concentration,and the error of the experimental concentration was reduced to within 5% from the maximum 17% before compensation.

A bronze mirror of Tang dynasty,were send to scientific analysis by three-dimensional microscopy,SEM-EDS and Raman spectrum analysis.The results indicated that:Ceruse,dolomite and crystal etc.were embedding in the bronze mirror;The gold plate and gold particle have high concentrations of silver (20%,Ag);The radius of these gold particle are different,which between 33.8~90.3 μm;The Raman spectrum analysis also indicated that,the green corrosion was Prussian blue.This indicated that the bronze mirror was a piece of Tang dynasty mirror that cover with gold leaf and embed with gemstones,but it was restored after 18 century AD.

In order to make up the shortage of calibration of visibility meter,built a suit of open path visibility calibration system device based on laser cavity enhanced technique.The calibration of the forward scattering visibility meter is achieved by simulating the visibility environment in the visibility simulation chamber,with monodispersed stearic acid particulate matters generated by aerosol generator.Contrast tests were taken with forward-scattered visibility meter in a small simulation chamber(length 2m×width 1m×height 1m)and transmission meter in large simulation chamber (length 20m×width 2.5m×height 3m).The results shows,within the visibility of 100~2000 m,the relative error with transmission visibility meter is less than 5%,and the relative error with forward-scattered visibility meter is less than 10%,and both of them show a good consistency.This system can be used in a smaller visibility simulation chamber,and provide a feasible technique method for laboratory calibration of forward-scattered visility meter.

To study the classification of on-site residual handkerchief paper plastic packaging bags,35 samples of different brands,different series and different colors were tested by Raman spectroscopy.According to the absorption peaks in Raman spectra,combined with K-means clustering method,different types of handkerchief paper plastic bag samples can be distinguished after the use of smooth function and similarity discrimination.The reproducibility and minimum detection amount are also investigated.These methods can protect the samples and has good reproducibility.Their objectivity is strong and they have low environment requirement.The paper provides a theoretical basis for the subsequent inspection to distinguish the contaminated and vulnerable fragments extracted.

Three-dimensional chiral shell-like silver nanostructures are fabricated by micro-sphere self-assembly and tilted vacuum thermal deposition techniques,and the nonlinear saturation absorption characteristics of the sample are investigated by Z-scan technique with 4ns pulsed Nd:YAG laser at 532 nm wavelength.Our results show that when the irradiation intensity reaches to 2.5×109 W/cm2,the derived nonlinear absorption coefficient β can achieve to -1.45×10-5 cm/W,which is four orders of magnitude larger than the nonlinear absorption coefficient -1.5×10-9 cm/W of colloidal silver nanoparticles in suspensions.We also found that the nonlinear absorption coefficient of the silver nanostructure changes significantly with the polarization direction of incident light.The enhancement mechanism and polarization dependence of the nonlinear absorption are analyzed and discussed.

Integral Imaging is a technique used to reconstruct light field in real space,which is capable for multi-viewers at the same time,and no additional accessory is needed and is easy to build as well,so it has the potential to be widely used among research,medical and entertainment,etc.However this traditional Integral Imaging has its limitation such as low resolution and restricted viewing angle,it has to make comprise among all those display parameters and to have no high performance for all the parameters and it would cost too much.So it is proposed to introduce Holographic Functional Screen into Integral Imaging that could reduce the cost.This paper present the theory of the Holographic Functional Screen based Integral Imaging and derived the formulae for display parameters.Those formulae can be used to design a display system for specific application and experiments is executed to verify the usefulness of the formulae.The experiment build a system with display resolution 790×444,the angle of view 60°,which are close to the parameters of Liquid Crystal Display system at its early stage,it may not be long for this technique comes into our life.

Yujiaba site is one of the most important Ba sites in the Three Gorges area.It is located at the northeast of Yujiaba,Kaizhou Disctrict,Chongqing and was discovered in 1980s.Burial objects characterized by bronze weapons have been unearthed after four excavations.This article applies non-destructive analysis with high-fidelity optical microscope and Raman spectroscope to observe the appearance and explore the structure of corrosion products on 10 bronze swords excavated from Yujiaba site.The result shows that the bronze swords can be classified into two categories:one with category with smooth and compact surfaces,the corrosion products of which are malachite,cassiterite and cuprite,the other one contains corrosion products,namingly malachite(Cu2CO3(OH)2),azurite(Cu3(CO3)2(OH)2),cuprite (Cu2O),cerussite (PbCO3),pyromorphite (Pb5(PO4)3Cl),mimetite (Pb5(AsO4)3Cl),brochantite (Cu4SO4(OH)6),cassiterit e(SnO2)and atacamite (Cu2Cl(OH)3).In addition,this article analyzes the cause of corrosion and tries to provide evidence for further conservation and restoration of those cultural relics and related research on corrosion of Ba bronze weapons.

A kind of crafts called “elephant bone” is very common in nowadays′jewelry market.It is impossible for us to identify it only by conventional techniques.To clarify its material properties,the spectral properties of this material and ivory were analyzed and compared in the present paper through the gemological tests,infrared spectrum,Raman spectrum and X-ray fluorescence spectroscopy.The results showed that this type of material has a refractive index RI:1.55 ±,showing a strong blue-white ultraviolet fluorescence,and has intermittent straight microcracks.FTIR,Raman and EDXRF test results showed that it is composed of biologically occurring calcium phosphate and collagen organic matter,as well as the mian trace elements Al、Zn、Sr,and its material composition is similar to that of ivory.However,due to having no Retzius stripes ,lack of the essential trace elements Mg,Si,and Its main elements Ca and P are higher than ivory.In the infrared absorption spectrum,the absorption peaks of C-O,C-H stretching vibration and N-H bending vibration of collagen amide bond between 1500~1700 cm-1 were significantly weaker than those of ivory.Together ,these characteristics make it distinguishable from ivory.It can be inferred as a bone product based on its surface microcracks,refractive index,and material composition.However,as there are not yet standard materials and data of elephant bone for reference,the author believes that it is very essential to figure the real source information of its origin,supply channels and process flow through market research to achieve more accurate identification of such handicraft materials.

Raman spectroscopy has been widely used in pharmaceutical analysis due to its remarkable characteristics such as avoiding the interference of water in samples,simplicity of sample pretreatment,rapid nondestructive analysis,and greatly enhancing the sensitivity of detection by Surface Enhanced Raman Spectroscopy.The purpose of this paper is to summarize the specific research examples of Raman spectroscopy in drug identification,drug quantitative analysis,drug crystal analysis,quality control process monitoring of drug production,pharmacokinetics and so on in the past ten years,and to make a comprehensive review of the research and application of Raman spectroscopy in the field of drug analysis,so as to provide necessary reference for future research in this field.

Millions of people are affected by eye diseases which can affect the shape and dimensions of the whole eye.For examination of ocular accommodation and pathological changes caused by these diseases,high resolution imaging of the whole eye segments OCT system is desired.However,limited by the imaging depth,traditional Fourier Domain Optical Coherence Tomography (FD-OCT)can’t be used for real time whole eye segment imaging.In recent years,techniques for depth extended FD-OCT system especially for whole eye segment imaging has been developed.Application on eye parameters measurement and eye accommodation studies were successfully performed.In this paper,both of whole eye FD-OCT techniques and the application were reviewed.Potential clinical application of these techniques may be in the detection of the pathological changes of the whole eye,and whole eye segment FD-OCT system also provides a powerful imaging method for ophthalmic research.