Under alkaline conditions, Fluorescein mercury has strong fluorescence, however, when it met S(2-), its fluorescence would quench, in view of the above, a fluorescence method for determination of H2S in biological samples was established. In the 0.1 mol · L(-1) NaOH dilution, when the concentration of fluorescein Mercury and Na2S was 5.0 × 10(-5) and 1.0 × 10(-5) mol · L(-1) respectively, the fluorescence intensity of system was determined at 522 nm. The results showed that, at the range of 4.0 × 10(-7)~2.0 × 10(-6) mol · L(-1), the concentration decreasing of H2S and fluorescence intensity had good linear relationship, r=0.9980, the RSD of precision test was 4.59% (n=7), the detection limit was 3.5 × 10(-8) mol · L(-1), the content of H2S in the sample were 1.01 × 10(-6) and 1.15 × 10(-6) mol · L(-1), and the recovery rate was 95.8%~101.0%, the method has the advantages of simple operation, high sensitivity, good selectivity, can accurately determine of H2S in intestinal perfused solution, and provides the basis for the determination of endogenous H2S.

Three-port tunable optical filter is a key device in the all-optic intelligent switching network and dense wavelength division multiplexing system. The characteristics of the reflecting spectrum, especially the reflectivity and the isolation degree are very important to the three-port filter. Angle-tuned thin film filter is widely used as a three-port tunable filter for its high rectangular degree and good temperature stability. The characteristics of the reflecting spectrum are greatly influenced not only by the incident angle, but also by the wedge angle parameter of the non-paralleled wedge thin film filter. In the present paper, the influences of the wedge angle parameter to the reflectivity and the half bandwidth are analyzed, and the reflecting spectrum characterstics are simulationed in different wedge angle parameter and polarity. The wedge angle-tuned thin film filter with 0.8° wedge angle parameter is fabricated. The experimental results show that keeping the wedge angle the same orientation to the incident angle will worsen the reflectivity and the rectangular degree of the reflecting spectrum. However, keeping the wedge angle orientation reverse to the incident angle will enhance the reflectivity and decrease the bandwidth, which will give higher reflectivity and isolation degree to the three-port filter than that of high parallel degree angle-tuned thin film filter.

Snow can directly affect the surface energy balance and climate change and has a significant impact on human life and production. It is therefore of great significance to study the fresh snow emission spectroscopy properties by using the thermal infrared Polarization technique. This can provide a basis for quantitative thermal infrared remote sensing monitoring of snow as well as a deeper understanding of global warming and appropriate countermeasures. This paper focuses on the investigation of the thermal infrared polarization properties of the fresh snow. The results show that the thermal emissive polarization properties of fresh snow depend significantly on the wavelengths (channels) and view angles used to measure them. Four channels are considered in this study, their spectral response ranges are 8-14 microm for channel 1 (CH1), 11.5-12.5 microm for channel 2 (CH2), 10.3-11.5 microm for channel 3 (CH) and 8.2-9.2 microm for channel 4 (CH4). The snow polarized radiance (L) and its polarized brightness temperature (T) manifest as L(CH1) >L(CH3) > L(CH4) > L(CH2) and T(CH4) > T(CH1) > T(CH2) > TCH3, respectively, while the degree of polarization (P) manifests as P0 > P30 > P40 > P20 > P0 > P50 where the subscript of P denotes the view angle. The maximum of both L and T occurs at the view angle of 50 degree and polarization angle of 90 degree while their minimum appears at the view angle of 30 degree and polarization angle of 75 degree for each channel. In addition, the results show that: CH3 is more appropriate for better investigation of the emissive polarization properties of snow. Linear relationship is found between the fresh snow polarized T and the polarization angle with the coefficient of determination larger than 0.77 for all four channels. The polarized brightness temperature of the fresh snow is found to be increased about 0.003 K per polarization angle within 0-135 degree. The degree of polarization of snow is almost independent of the channels we used (CH1 to CH4). The snow emissive polarization is isotropic and the relative azimuth view angle has no significant impact on the snow emissive polarization properties. The impact of the polarization angle may be neglected if the investigation of the relative azimuth view angle on the fresh snow thermal emissive polarization is conducted. The difference of the fresh snow emissive polarization properties mainly comes from the snow surface roughness and structure.

The samples from several treatment units in wastewater treatment plant (WWTP) and different sample sites of receiving waters were characterized using excitation-emission matrix (EEM) fluorescence spectroscopy. After analyzed by parallel factor analysis (PARAFAC) method, the EEM fluorescence spectra of the principal components and fluorescence intensity scores matrix were acquired. Results showed that protein-like and fulvic-like substances were the main components of the samples from the WWTP and the receiving water body. The intensity of protein-like fluorescence in the influent samples was rather strong, and those of the following samples decreased significantly. The protein-like fluorescence intensity of the samples was relatively weak from the upstream of receiving water body, while those of the samples increased significantly from the water body near the urban area. The protein-like fluorescence intensity of upstream samples of the WWTP disposal outlet was stronger than that of downstream in the receiving waters. The fluorescence intensity scores of protein-like substance could be correlated with the COD concentration of the samples and the correlation curves were established. The correlation coefficient of the WWTP samples was 0. 930 and that of receiving water body samples was 0.913. The protein-like fluorescence could be used to evaluate the organic pollution of the samples. This study will provide a new method to investigate the operation status of WWTP and corresponding effect on the receiving water body.

The present paper put forward a non-destructive detection method which combines semi-transmission hyperspectral imaging technology with manifold learning dimension reduction algorithm and least squares support vector machine (LSSVM) to recognize internal and external defects in potatoes simultaneously. Three hundred fifteen potatoes were bought in farmers market as research object, and semi-transmission hyperspectral image acquisition system was constructed to acquire the hyperspectral images of normal external defects (bud and green rind) and internal defect (hollow heart) potatoes. In order to conform to the actual production, defect part is randomly put right, side and back to the acquisition probe when the hyperspectral images of external defects potatoes are acquired. The average spectrums (390-1,040 nm) were extracted from the region of interests for spectral preprocessing. Then three kinds of manifold learning algorithm were respectively utilized to reduce the dimension of spectrum data, including supervised locally linear embedding (SLLE), locally linear embedding (LLE) and isometric mapping (ISOMAP), the low-dimensional data gotten by manifold learning algorithms is used as model input, Error Correcting Output Code (ECOC) and LSSVM were combined to develop the multi-target classification model. By comparing and analyzing results of the three models, we concluded that SLLE is the optimal manifold learning dimension reduction algorithm, and the SLLE-LSSVM model is determined to get the best recognition rate for recognizing internal and external defects potatoes. For test set data, the single recognition rate of normal, bud, green rind and hollow heart potato reached 96.83%, 86.96%, 86.96% and 95% respectively, and he hybrid recognition rate was 93.02%. The results indicate that combining the semi-transmission hyperspectral imaging technology with SLLE-LSSVM is a feasible qualitative analytical method which can simultaneously recognize the internal and external defects potatoes and also provide technical reference for rapid on-line non-destructive detecting of the internal and external defects potatoes.

A cavity ring-down spectrometer (CRDS) was built based on telecom distributed feedback (DFB) diode lasers. The ring down cavity was formed by mirrors of 99. 997% reflectivity with a separation of 130 cm, with an empty ring down time of about 150 µs. A minimum detectable absorption coefficient of 5 x 10(-12) cm(-1) was obtained by averaging about 1,000 recorded spectra. The ring down cavity is thermo-isolated, and used as an interferometer to calibrate the recorded spectrum. A feedback control scheme was applied to step scan the laser frequency, successively matching each of the longitudinal modes of the cavity. By measuring the CO contents in a standard gas sample, the quantitative capability of the CRDS instrument was demonstrated, and a CO detection limit of 4 ppb was achieved. The instrument was applied to monitor the CO concentration in ambient air.

This review paper reports near-infrared (NIR) imaging studies using a newly-developed NIR camera, Compovision. Compovision can measure a significantly wide area of 150 mmX 250 mm at high speed of between 2 and 5 s. It enables a wide spectral region measurement in the 1,000-2,350 nm range at 6 nm intervals. We investigated the potential of Compovision in the applications to industrial problems such as the evaluation of pharmaceutical tablets and polymers. Our studies have demonstrated that NIR imaging based on Compovision can solve several issues such as long acquisition times and relatively low sensitivity of detection. NIR imaging with Compovision is strongly expected to be applied not only to pharmaceutical tablet monitoring and polymer characterization but also to various applications such as those to food products, biomedical substances and organic and inorganic materials.

The authors prepared nc-SiOx: H thin films using plasma enhanced chemical vapor deposition methods (PECVD) and investigated the influence of oxygen incorporation on the microstructure and band gap properties of the films. The results indicated that with the increase in oxygen mixing ratio (CO2/SiH4), the grain size of the nanocrystal-silicon grain as well as the crystallinity of the film reduced, and the surface tensile stress of the nanocrystal-silicon grain first increased and then decreased. Fourier infrared absorption spectra analysis indicated that, with the increase in oxygen mixing ratio, the intensity of the oxygen rich Si--O bond increased while that of the silicon rich Si--O bond decreased and the structure factor reduced in the meantime accompanied by the improved order degree of thin films. The structure factor increased when the oxygen mixing ratio exceeded 0.08, which shows that the order degree of thin films dropped. In addition, the optical gap increased and the band tail width first increased and then decreased as a result of the incorporation of the oxygen. As a result, the microstructure and band gap properties of the films can be controlled by incorporating oxygen. And the crystallinity and optical gap of the material was high, and the microstructure of the films was improved at the same time when the oxygen mixing ratio was 0. 08, so it can be used as intrinsic layer of the thin-film solar cells.

Spectrometric oil analysis is of great importance for wear condition monitoring of gearbox. In this context, the contents of main elements compositions in the bench test of heavy vehicle gearbox are obtained by atomic emission spectrometric oil analysis first. Then correlation analysis of the test data and wearing mechanism analysis are carried out to get the metal element which could be used to describe the wearing and failure of the gearbox. The spectrometric data after filling/changing oil are corrected, and the laws of the contents of main elements compositions during tests are expressed as linear functions. After that, the reliability assessment is executed with considering the degradation law and discreteness of test data, in which the mean and standard deviation of normal distribution of spectrometric oil data at each time point are adopted. Finally, the influences of the threshold are discussed. It has been proved that the contents of metal element Cu, which is got by spectrometric oil analysis of different samples, could be used to assess the reliability of heavy vehicle gearbox. The reason is that the metal element Cu is closely related to the general wear state of gearbox, and is easy to be measured. When the threshold of Cu content is treated as a constant, bigger threshold means higher reliability at the same time, and the mean value of threshold has significant impact on the reliability assessment results as R > 0.9. When the threshold is treated as a random variable, bigger dispersion of threshold means smaller slope of reliability against time, and also means lower reliability of gearbox as R > 0.9 at the same time. In this study, the spectrometric oil analysis and probability statistics are used together for the reliability assessment of gear box, which extends the application range of spectrometric analysis.

The spectrum of surface plasmon resonance shows different amplitudes and peak widths with theeffects of resonant intensity and position, so it's necessary to develop the self-adaptive methods to guarantee the accurate positioning of SPR formant. Based on the optimized Savitzky-Golay filter, this paper presents a method for SPR spectrum, which can optimize the parameters (polynomial degree and window size) according to the characteristics of the real time SPR spectrum, and minimizes the Stein's unbiased risk estimate of the mean squared error, and it can be quickly solved by Monte-Carlo methods. It is confirmed that SURE can accurately reflect the trends and the results of the true MSE. The experiment measures the SPR signals of sucrose under different concentrations and integration time through the SPR system. By using the proposed method of optimal parameters on the SPR signal filtering, the results show that the repeatability error of the position of SPR formant is smaller compared with the fixed parameters, and does not increase with the addition of noise levels.