Two-dimensional transition metal sulfides are emerging materials with a variety of unique properties, such as maximum electrostatic efficiency, superior mechanical strength, tunable electronic structure, excellent optical transparency, and sensor sensitivity, and are considered potential, ubiquitous electronic, energy, and sensor devices This paper reviews the applications and research progress of Two-dimensional transition metal sulfides in the fields of electrochemical sensors, photochemical sensors, and biosensors,and describes the optimization of their catalytic activities by designing and modulating the positions of metal sulfide energy bands and performing atomic doping, etc, so as to make them more excellent in sensitivity and thus expand their application fields Meanwhile, the development status and advantages of SERS technology in conjunction with the now popular nanozymatic catalytic technology are discussed Finally, the challenges and prospects for the development of 2D transition metal sulfides in sensor technology are envisaged
Solid-state nanopore has emerged as a powerful singlemolecule method due to its labelfree and highthroughptu capabilities, and high temporal and spatial resolutionIt has been widely used in the detection of single molecules,including DNA, RNA, proteins,metal ions and others This review mainly focuses on the integrated system of plasmon resonance scattering spectroscopy and Solid-state nanopores, summarizes the research progress in this field, briefly discusses the princeples, fabrications and applications of these electrooptical nanopore, and further prospects the Raman scattering spectroscopy in Solid-state nanopores
Raman scattering faces problems such as weak signals and limited detection sensitivity in the process of molecular detectionIn order to achieve higher detection sensitivity and even single molecule detection, in recent years, researchers have applied plasmonic nanopores as surface enhanced Raman scattering (SERS) substrate to measure the Raman signals of molecules passing through/sitting in plasmnoic nanopores In this paper, we reviewed the basic principles of nanoporebased SERS biosensors, the fabrication methods, and application on the detection of different molecules, such as DNA, peptides, and neurotransmitters It also analyzes the future development trends of using nanopore SERS technology
In this study, the main components and its contents of Compound Sodium Salicylate, Antipyrine and Caffeine Injection were analyzed by Raman spectroscopy Firstly, the Raman spectra of 62 Compound Sodium Salicylate, Antipyrine and Caffeine Injection samples were analyzed, and the results showed that the Raman spectra of 62 injection samples were mainly composed of the Raman spectra of sodium salicylate aqueous solution, antipyrine aqueous solution and caffeine aqueous solution Furthermore, the theoretical Raman spectra and infrared spectra of the main components were calculated by density functional theory, and compared with the experimental spectra of solid powder and aqueous solution, and then the vibration modes of Raman spectral peaks of Compound Sodium Salicylate, Antipyrine and Caffeine Injection were assigned Finally, the quantitative analysis models using the spectral characteristic peaks height or peaks area of sodium salicylate gradient solution and antipyrine gradient solution were established, respectively Then, the contents of sodium salicylate and antipyrine in 62 injection samples were predicted by the quantitative analysis models, and the predicted values were compared with those measured by liquid chromatography The results showed that the predicted values were close to the measured values The better content prediction results of main components were obtained The study can provide reference for the monitoring of drug quality, the research of drug spectrum analysis and the production of Compound Sodium Salicylate, Antipyrine and Caffeine Injection
Four zwitterionic compounds of sulfamic acid type: sulfamic acid (SA), aminomethanesulfonic acid (AMA), taurine (TAU), and 3amino1propanesulfonic acid (APA) were selectedFouriertransform infrared spectroscopy (FTIR) was employed to investigate the zwitterionic structures of these compounds The results demonstrate the presence of zwitterionic forms for all four substances, as evidenced by the presence of stretching vibrational peaks for NH3+ and SO3- in the infrared spectra Phase transition temperatures and thermal stability were analyzed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) The results indicate that all four zwitterionic compounds undergo melting accompanied by decomposition, with taurine exhibiting the highest thermal stability
To rapidly detect different manufacturers and batches of Wai Yong Kui Yang San, Raman spectroscopy combined with principal component analysis (PCA) support vector machine (SVM) algorithm was used to classify and identify different manufacturers and batches of Wai Yong Kui Yang San The results show that although the difference of Raman spectra is very weak, it can not be directly classified and identified by naked eyes, but PCASVM algorithm can accurately classify and identify different manufacturers and batches of Wai Yong Kui Yang San, and the accuracy rate is 100% This method is rapid, accurate, nondestructive and simple, and has potential application value for classification, identification and quality control of different manufacturers and batches of Wai Yong Kui Yang San
Organic-inorganic hybrid perovskite is an important photoelectric material,which is widely used in photovoltaic devices And their stability will significantly improve when sample limited in MOFs,however,the effect of limitation on its photodetector performance is still under investigation In this study,MAPbBr3 were limited in ZIF67,a typical MOFs material,and by adjusting the amount of ZIF67, MAPbBr3@ZIF67 with different concentrations ZIF67 was formed It was found that the addition of ZIF67 did not affect the lattice structure and absorption edge position of MAPbBr3,but could improve its crystallinity In addition,since ZIF67 still has significant absorption at wavelengths longer than 550 nm,the composite also shows significant absorption characteristics in this wavelength range When the synthesized sample used in photodetector,the corresponding switching ratio of the device is improved more than an order of magnitude This study provides a new idea for further improving the response performance of the device
In this paper, the optical properties of CeV2 color center of diamond are calculated by using VASP software package based on the first principles method of density functional theory The static dielectric function of the color center is determined to be 192 theoretically The refractive index of color center is calculated, and the refractive index of color center is 438 The extinction coefficient and absorption coefficient are calculated, and it is found that the extinction coefficient and absorption coefficient of color center decrease obviously The reflection coefficient is calculated, and it is found that the reflection coefficient of the color center is first high and then low, and the transmittance of the color center decreases in the low energy region and increases in the high energy region By calculating the energy loss coefficient, it is found that the energy loss coefficient of the color center increases Because of the high energy loss, it is very important to excite the color center in the range of excitation wavelength length We have verified the optical properties of CeV2 color center of diamond theoretically, which provides a theoretical basis for the subsequent experimental detection
In this paper, Near infrared spectrum (NIR) technology is used to establish a clothing material and content detection model Selecting 8 kinds of clothing samples and cottonpolyester blended fabrics as test objects, the detection model of clothing material and content was established through data preprocessing, feature extraction, classification recognition and regression analysis The experimental results show that the qualitative discriminant model established by the least square vector machine has higher accuracy and shorter operation time The quantitative analysis model based on the NIR data of the cottonpolyester mixed fabric after the second derivative smoothing and pretreatment combined with the partial least square algorithm has good accuracy and stability, and the predicted rootmeansquare error reaches 0001 9, which meets the accuracy requirements of the NIR rapid detection The near infrared detection method established in this paper has the advantages of environmental protection, short time and low cost, and has certain application value in the fields of clothing manufacturing, quality assurance and quality inspection This study provides a new method and idea for the detection of fabric material and content, which has certain theoretical and practical application value
In recent years, Spatially Offset Raman Spectroscopy (SORS) has gained significant applications due to its unique and efficient capability to detect target substances concealed within strongly scattering interfering media Extensive and profound investigations have been conducted to demonstrate the performance characteristics of SORS However, there is a lack of a comprehensive study exploring the detection of materials with varying optical properties by SORS This research endeavors to bridge this gap by constructing a concise bilayer model In this model, two distinct interferents with different optical properties are layered onto the target material Through the analysis of the Raman intensities originating from the surface interferent and the underlying target material, we investigated the SORS performance when probing substances with varying degrees of scattering Our findings indicate that under identical detection conditions, the higher scattering surface interferent need a larger spatial offset for effective detection by SORS Consequently, this study demonstrates the substantial potential of SORS technology in noninvasive detection applications for sublayer components Moreover, it provides a comprehensive understanding of the SORS
Using a heated shock tube and an spectroscopic detector ICCD,transient emission spectra of triethylamine in the combustion reaction were measured in the range of ultraviolet to near infrared Experiments were conducted at a pressure of 15 atm and a temperature of 1500 K Results show that the main emission bands are attributed to NO, OH, NH, CN and CH radicals produced during the combustion process,and the small radicals NO, OH, NH, CN, and CH are the important reaction products in the combustion process of triethylamine,and the spectrum of CN radical is obviously stronger than that of CH radical;Determined the electron level transitions corresponding to the characteristic spectra of NO, OH, NH, CN, and CH radicals Analyzed the production mechanism of small free radicals of NO, OH, NH, CN and CH from the perspective of chemical reaction with the theory of combustion kineticsThe results provide experimental basis for understanding the microscopic process of triethylamine combustion reaction and verifying the mechanism of triethylamine combustion reaction
In the small angle X-ray scattering (SAXS) experiment of Beijing Synchrotron Radiation Facility (BSRF), the measurement of noninsitu samples usually occupies a large proportion The experimental efficiency is low by using the traditional sample holder which carries a single sample at a time In this work, an automatic sample changing device is designed for SAXS experiment at synchrotron radiation facility It can carry ten samples at a time, and the sample movement, light alignment and exposure can be operated by wireless remote control outside the experimental hutch, which increases the experimental efficiency This paper briefly introduces the basic structure, function and application of the device
Famille-rose is one of the four famous types of porcelain in Jingdezhen. Its characteristics of soft powder and rich color are closely related to the nature of the raw materials used. Scientific detection of famille-rose porcelain can provide a basis for studying the inheritance and development of famille-rose porcelain. Three-dimensional video microscope, X-ray fluorescence scanning Imager (MA-XRF) and Raman spectrometer were used for in situ nondestructive testing of Yongzheng famille-rose bottles in the collection. It was found that the coloring agent of purple color was gold red, the coloring agent of red color was alum red, the coloring agent of green color was copper compound, the coloring agent of yellow color was lead-tin yellow type II, and the yellow-green color was made of green color and yellow color.The black colorant is manganese oxide. The combination of microscope and MA-XRF can reveal the relationship between the upper and lower layers of the pigment, the painting technique of the famille-rose, the characteristic elements of the pigment and its distribution position. The application of three kinds of in-situ nondestructive testing instrument can provide reference for the scientific research of the contents of complete porcelain colorant and painting techniques.
Zhihua Temple is one of the most typical temples built in early Ming Dynasty. It has great value of study thanks to the well-preserved buildings after the Ming, Qing, and Republican periods, combining with the architectural styles in Song and Yuan Dynasty.Three big stone carvings in the temple have obvious black pollutants on their surfaces. It is necessary to carry out scientific analysis and research on the unknown black pollutants, for the purpose of protecting stone historical relics effectively. The portable X-ray fluorescence spectroscopy (pXRF), Raman spectroscopy, Fourier-transform infrared spectroscopy (FT-IR) and pyrolysis gas chromatography-mass spectrometry (Py-GCMS) were used to analyze the composition of the contaminants. The results indicated that the pollutants were mainly composed of dry plant oil, as well as amorphous carbon and a small amount of protein residues. As for the black attachments on the back of the BiXi (Stone Turtle) in front of the Tathagata Hall, polysaccharides, lipids, amorphous carbon, cellulose, protein residues and quartz could be figured out through results. A scientific basis for identifying the black pollutants on the stone carvings in Zhihua Temple accurately was obtained by this study, which had a great significance for making an effective protection plan of related stone historical relics.