A comparative study of Cannabis sativa (Hemp) essential constituents obtained by using Supercritical Fluid Extraction (SCFE), Steam Distillation (SD) and Hydrodistillation (HD) is presented here. The optimized extraction temperatures were 130，110 and 50 ℃ for hydrodistillation, steam distillation and supercritical fluid extraction respectively. The essential oil of C. sativa was analyzed by using Gas chromatography mass spectrometry (GC-MS). A total of 33, 30 and 31 components have been identified in HD, SD and SCFE respectively. Yield of essential oil using SCFE (0.039%) was more than HD (0.025%) and SD (0.035%) extraction respectively. The main component of sesquiterpenes obtained by hydrodistillation at 130 ℃ with their percentages included caryophyllene (40.58%), trans-α-bergamotene (5.41%), humulene (10.97%), cis-β-farnesene (8.53%) and monoterpenes included α-pinene (2.13%), d-limonene (6.46%), p-cymol (0.65%) and cineole (2.58%) respectively. The main component of sesquiterpenes obtained by SD steam distillation at 110 ℃ including caryophyllene (38.60%) trans-α-bergamotene (4.22%), humulene (10.26%), cis-β-farnesene (6.67%) and monoterpenes included α-pinene (3.21%), d-limonene (7.07%), p-cymol (2.59%) and cineole (3.88%) whereas the more percentages of major components were obtained by SCFE at 50 ℃ included caryophyllene (44.31%), trans-α-bergamotene (6.79%), humulene (11.97%) cis-β-farnesene (9.71%) and monoterpenes included α-pinene (0.45%), d-limonene (2.13%) p-cymol (0.19%) and cineole (1.38 %) respectively. We found yield/efficiency, chemical composition, quality of the essential oils by supercritical fluid extraction superior in terms of modern, green, saving energy and a rapid approach as compared to traditional techniques.

The samples with different carbon content are collected for quantitative analysis. One of the normal methods is the ignition of different coals according to the notice of fast ashing method instead of collecting coal ash in boiler. But there are some differences between fast ashing method in laboratory and actual boiler. It is necessary that the spectral deviation of coal ash from these two sources is studied as a guidance of quantitative analysis in carbon content. In present work, the intensity of the characteristic lines and plasma temperature were compared with different carbon content from these two processes. As a result, Fe, Mg, Al line strength of ash with fast ashing method is stronger and plasma temperature is lower than coal ash in boiler. Principal component analysis was processed, the results show that the difference of Fe, Mg, Al and Si content is the primary factor, and minerals in coal ash with fast ashing method may influence the spectral characteristic. The influence of mineral elements and mineral content on spectra for quantitative analysis with fast ashing method should be noticed.

Terahertz spectrum is sensitive to the change of the nonlocal molecular vibration mode. Accordingly, the spectral waveform is susceptible to variety of physical and chemical factors, which will lead to peak changes, frequency shifts, and even deformation of the overall waveform. Component analysis and material identification from the correspondence between the fixed peak features and materials will prone to cause errors or mistakes. Therefore, to solve this problem, we proposed a method based on Kernel Optimization Relevance Vector Machine (KO-RVM), which extracts global graphic features to distinct from the local features extraction method. And we use Support Vector Regression (SVR) algorithm as comparison. The result shows that, when basis functions’ parameters of RVM are optimized with expectation-maximization algorithm, it will be suitable for feature extraction of terahertz transmission spectrum. The spectrum can be sparsely represented, and the amount of extracted graphic features is substantially reduced. Reconstruction models based on these features are capable of retaining the overall spectral characteristics, and fitting results for each band are more consistent, while the extracted spectrum features can be used as basis of similarity measurement and the common characteristics investigation between different materials.

Yogurt is a food produced by bacterial fermentation of milk. All kinds of nutrition components are changing dramatically in the process of fermentation. Therefore, it is important to establish a fast and efficient measurement technology of yogurt nutrition, which is also an important goal for food safety supervision in terms of monitoring the yogurt production process in real time. Fourier transform infrared spectroscopy (FTIR) has been widely used in the field of food safety, for it has high efficiency, high throughput, no chemical pollution, thus it can be used in the inspection of food adulteration. Our study has established a quantitative model to predict the nutrition components in yogurt, such as energy value, protein, fat, carbohydrates and sodium content. Based on the least squares (PLS) method, the model used CaF(2) film FTIR technology. The results show that the new model can be used in quality control of yogurt production process: The R(2) values of the model were 0.938 9, 0.926 6, 0.918 6, 0.941 8 and 0.977 1, comparing energetic value, protein, fat, carbohydrate and sodium contents with the original spectrum of calibration samples by cross validation. And the predictive R(2) are 0.920 5, 0.905 3, 0.908 5, 0.939 3 and 0.936 4 respectively. Thus, the model has good prediction accuracy and reliability, which provides a feasible method for the rapid measurement of yogurt quality. As a preliminary exploration of the quality control technology of dairy products, this method has a good prospect of application.

To improve time resolution of the Raman measurement system, we need to adopt short scanning time. In this case, the weak Raman signal with vibrational spectrum of the molecular structure is easily to be buried by the high background noise, which influences the further analysis seriously. So it is necessary to de-noise the raw Raman signals. Conventional methods manage to de-noise signal by means of smoothing or averaging based on the difference between signal and noise in frequency characteristic or statistical features. They are commonly applied in the situation where the background noise is not so strong, and cannot give satisfactory results to the Raman signals with low signal-to-noise ratio. In this paper, the algorithm proposed detects peak positions and get peak half-width based on wavelet transform, and then reconstructs the Raman signals by least square fitting algorithm with characteristic parameters obtained, which extracts the useful signal from high background noise efficiently. In the simulation, the Raman curve fitted by the proposed algorithm was smooth, and the peak positions obtained were accurate, so the signal-to-noise ratio improved significantly. In the experiment, we adopted this algorithm to de-noise the tested Raman signal of Cefuroxime Axetil Tablets and Roxithromycin, respectively. The peak positions, peak half-width and amplitude were obtained and proved to be accurate. Therefore, the useful pure Raman signal could be recovered from the high background noise efficiently by the proposed algorithm, which improved the time resolution of Raman system. Both the simulation and the experiment showed that the proposed method could be easily performed with only a few parameters. Comparing with conventional methods, it could achieve satisfactory results under high background noise and provide accurate and reliable information for further analysis.

In the study, zinc methyl mercaptobenzimidazole (MMBZ) was synthesized by one-step method. MMBZ was detecued and characterized by FTIR, UV-Vis, XRD, TG-DSC. Its micro-structure and intrinsic regularity were revealed. Chemical bond types into MMBZ molecule were revealed by FTIR. The final product was determined MMBZ. There absorption peaks were detected by UV-Vis at 219.6，245.5，302.2 nm respectively, due to n→σ(*)，π→π(*)，π→π(*) electronic transitions, led by S—C, benzene and five element heterocyclic in MMBZ molecule. It could provide experimental basis with enterprise to test MMBZ product quality and speculate its structure. It was shown that MMB was a ligand of MMBZ, and its basic structure of MMB was retained still by XRD spectra. The structure of MMBZ molecule was amorphous. Two kinds of information were detected with TG-DSC as quality change and thermal effect. There were five absorption peaks of 67.5, 155.3, 253.7, 324.8, 391.3 ℃, due to impurity solvent decomposition peak, phase transition peak and decomposition of MMBZ respectively. The scheme of one step preparation of composite environment-friendly rubber antioxidant MMBZ was feasible. The structure of MMBZ could be speculated by results of its detecting. It could provide the basis of experimental data on association MMBZ performance, exploring its anti-aging mechanism and extending the scope of MMBZ application.

In fiber-optic communications, in order to achieve more data channels in the wavelength division multiplexing (WDM) system without changing the modulation wavelength range, a new type of small-sized narrowband polarizing beam splitter was designed. It can be used for data communication network expansion and improve the Signal to Noise Ratio (SNR) of the optical signal. Two kinds new film system designed were deposited on the polarizing beam splitter. One layer is narrowband filter film, while the other layer is polarizing beam splitter film. TFCalc software was used for simulation analysis, and the results shown that the bandwidth of the narrowband filter film was about 0.4 nm, and the permeability of p light from the polarizing beam splitter film was better than 99.8% in the range of 1 530～1 560 nm. Based on the above film system design, two groups film system was made on BK7 optical glass. In the experiment, light through film was spectral analysis with Agilent 8164-A type optical measuring instrument. Experimental results show that the actual bandwidth of the narrowband filter film is better than 0.4 nm, gain flatness is not less than -0.05 dB. It has a narrower bandwidth compared to the existing common 0.8 nm filter film, and it can be realized to increase the amount of data channels in the wavelength division multiplexing system with the same modulation wavelength range. Actual transmittance of p light was 99.6% through polarizing filter film, and it’s slightly lower than the simulated values, but it remains better than the design requirements. Compared to conventional polarizing beam splitter, its optical signal was stronger, and it has a higher SNR. In summary, the polarizing beam splitter has better application value and practical significance.

With high degree of metamorphism and carbon content, anthracite is commonly used for activated carbon. The structural properties of anthracite play a decisive role in its materialization, while with chemical oxidation, anthracite structure can be purposefully improved. The anthracite oxide was prepared via acid leaching and oxidizing, using high carbon content and low ash content anthracite from Zhaotong, Yunnan Province, China. The structural and spectroscopy characteristics of anthracite and anthracite oxide were acquired with X-ray diffraction (XRD), Raman spectroscopy and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The results show that crystallites in anthracite have intermediate structures between graphite and amorphous. Compared with bitumite and lignite, its structure order degree lies between graphite and low metamorphic coals with relatively high average diameter of coal crystallites(La) and average height of coal crystallites (Lc). The process of anthracite oxidation can be modeled in two steps, the edge of crystal was curled and destroyed with strong oxidation, with the generation of CO group and intercalation of HNO3/H2SO4 into the edge layers, leading to the reducing of lateral sizes; HNO3/H2SO4 were continually intercalated into crystals, resulted in the increase of interlayer spacing (d(002)) from 0.351 to 0.361 nm, and the number of stacked layers dropped to 4.5 from 6 due to exfoliate. ID1/IG in Raman spectroscopy increased from 1.9 to 2.0, with full width at half maximum (FWHM) of G bond and intensity of D2 bond increasing from 63 to 68 and 10.26 to 13.78. Numbers of new —C—O—, CO, —NO2 groups generated, leading to the decrease of oxygen-containing functional groups content from 0.11 to 0.42. After HNO3/H2SO4 oxidation, the aromaticity (fa) of anthracite oxide increases, with the decrease of structure order degree and more-over a lot of active reaction sites generates in the process. The oxidation of anthracite enables anthracite has great potential in the application of porous carbon preparation.

Chlorophyll-a (Chl-a) concentration is one of the most important parameters for the analysis of inland water quality. Remote sensing data with the advantages of wide spatial area and multi-temporal monitoring has been applied as a reliable source of Chl-a concentration. However, as optical characteristics of inland water bodies are complex with high spatial and temporal (diurnal) variations, there are still limitations to estimate Chl-a concentration with traditional remote sensing data and single model. In the proposed solution, the first geostationary ocean color satellite sensor, Geostationary Ocean Color Imager (GOCI), which provides an image per hour (eight images per day from 8:16 to 15:16), was used as a data source of Taihu Lake. Based on hierarchical clustering method, water types were identified from in situ normalized spectral reflectance collected in Taihu Lake (216 samples in different seasons from 2010 to 2012). Then eight GOCI images which were obtained on May 6th, 2012 were classified separately according to different water types by calculating spectral angle distance between each spectrum in GOCI images and the classified spectra. According to the classified remote sensing images and the spectral bands of GOCI data, classed-based models were subsequently developed for the estimation of Chl-a concentration. The results indicated that four water types (Type 1 to Type 4) were identified based on the in situ normalized spectral reflectance in Taihu Lake. The spectra of Type 1 mainly represented the characteristics of floating algae. This type had little significance to in estimating Chl-a concentration because sensors could only receive signal of floating algae. Then Type 1 was usually used as the evidence of algal blooms. Meanwhile, two-band semi-analytical algorithms were established for Type 2—Type 4 waters which were separately dominated by Chl-a concentration, high suspended solid, low Chl-a and low suspended solid. Comparing with the two-band algorithms, band 7 and band 6 combination was more suitable for Type 2 and Type 3 while the correlation between Chl-a concentration and b7/b5 was higher than that between b7/b6 for Type 4. The accuracies of classification models (Type 2—Type 4) were higher than that of the overall model, with the reduced average relative errors of 7%, 12.3% and 15.9%, respectively. Moreover, the inversion results of GOCI data not only reflected the spatial distribution of Chl-a, but also showed the diurnal variation of the Chl-a concentration of Taihu Lake. This study has demonstrated great potential for dynamic monitoring of eutrophication pollution with GOCI data. In addition, the results suggested that optical classification algorithm can improve the accuracy of Chl-a concentration and the application performance of semi-analytical model. GOCI data and the class-based algorithm provide a basis for accurate estimation of diurnal and spatial variation of Chl-a concentration.