[Study on the Spectral Characteristics of Xeon Flash Lamp and Experimental Measurement].

Xenon flash lamp is used by most analytical instruments and medical equipments as light sources whose spectral characteristics exert a tremendous influence on the property of instruments and medical equipments. In order to study the effects of pulsed Xenon discharge circuit parameters and geometric parameters on the spectral characteristics, theoretical analysis has been conducted to Xenon lamp emitting process with the gas discharge theory. The spectroscopic detection system has been designed to conduct experimental detection to the spectral characteristics of pulsed Xenon lamp with different parameters. The experimental results show that the emission spectra of Xenon flash lamp contain both line and continuous radiation. The line spectrum results from the electron energy gap transition, while the cw radiation related to ionic recombination and bremsstrahlung. The relative spectral intensity increases linearly with the discharge voltage, and has a positive correlation with storage capacitor. When low discharge voltage, the shorter the arc length, the higher the relative spectral intensity .while the discharge voltage becomes higher, the result is reversed. The work in this paper has great significance for xenon flashlamp on the parameters selection and industrial application.

[Research on Water Quality Analysis Model with PCA Method and UV Absorption Spectra].

Using the UV absorption spectrum to detect Organic pollutants content in water has become one of the most important methods for real-time online monitoring in the field of water quality inspection, however, the water complex and unstable components often bring much uncertain offset to the standard test. In this paper, water samples were classified firstly by analyzing UV absorption spectrum ranging from 200 nm to 400 µm including the organic substances, through the way of combining principal component analysis (PCA) with Euclidean distance. In this paper, we compared the Principal component analysis combined with partial least squares regression (PCA-PLSR) and the direct multi-wavelength absorption models combined with partial least squares regression (MWA-PLSR), not only for the real water sample but also for the analysis of different concentrations of COD standard solution. The result indicates that the measurement errors of the PCA is less than 5%, it is the smallest by using the first and second principal components as regression parameters for PLSR. Using the methods above can simultaneously achieve to classify of water samples and to measure the concentration of water quality parameters more accurately.

[Study on the discharge properties of xeon flash lamp and experimental measurement].

The Xenon flash lamp is a new type of light source for analytical instrument. The present paper analyzed the discharge process of xenon flash lamp, presented the discharge test system, and conducted experimental measurement of the voltage, current and optical pulse signal in the process of discharge. The results show that in the preliminary discharge, the free electron concentration was at a low level, so the energy was at a low level, then following the gas discharge, numerous free electrons formed in the lamp, resultin in the increase in the concentration of free electrons, therefore discharge current rised rapidly and voltage reduced. The lamp released photons to generate light pulse in the moment of ionic recombination, The pulse xenon lamp light energy output and spectral characteristic is related to electron energy in recombination and combination level of xenon, if the input energy and the energy consumption of the xenon lamp is inconsistent, it will lead to repeated capacitor charging and discharging and produce oscillation waveform. This paper is very useful for understanding the process of xenon lamp discharge, optimizing the driver circuit and the production of xenon flash lamp.

[Research on the online detection of oil concentration in water].

A novel technology to measure oil concentration in water is presented, and mie-scattering theory was creatively introduced to oil-in-water detection in the present study. A variety of oil samples were examined to obtain both scattering and infrared absorption spectra, and the linear correlation between light scattering intensity and measures with infrared spectrophotometry is more than 0. 98. In addition, compared to the conventional methods, light scattering method requires no chemical reagent, and it is suitable for in situ measurement of oil in water.

[Research on detection of oil in water based on near-infrared scattering method].

The harm assessment and responsibility of marine mineral oil pollution require the content of mineral oil to be obtained by real-time online monitoring. In the present paper, the method of online monitoring of the oil content in water is presented, a creative technology based on optical scattering theory was proposed. Firstly the particle distribution of oil drops was scanned by Marvin laser particle meter, then with the help of the scattering signal, the crude, diesel of different concentrations from 0 to 30 mg x L(-1) was measured in experiment, the linearity is more than 0.99. This paper presents a feasible setup for the online monitoring of the content of mineral oil.

[A novel technology for water quality testing based on UV spectral analysis].

Water pollution control and prevention require that the water quality testing is of real time, online and portability. The presejt paper provides a water detecting system based on UV-visible spectra. The R2 of the linear regression is greater than 0.99 between absorbance and COD of the samples. Single measurement is within 1 s. At the same time, two methods were presented for direct comparison and normalization of the spectra and their corresponding indicator parameters. By a large number of experiments with standard solution of the potassium hydrogen phthalate and water samples, we found that these methods can be used to classify samples, find suitable mathematical model of the test water from the database, to improve the universal ability of the UV water testing technology, and get other water quality indices.

[Spectral measurement system and laser therapy experiments for port wine stains].

To measure and analyze the spectrum of a small skin region for laser therapy of port wine stain is very useful for clinical doctor to understand the optical characters of patient's pigmented skin, to adjust the output parameters of lasers and then to improve the therapy effects. Based on the analysis of the forming mechanism of port wine stains and clinical operation of the disease, the present paper presents an automatic spectral measurement and analysis system for port wine stain therapy. It can accomplish the spectral detection in the range from 380 to 780 nm, with a spectral resolution of 1 nm. Experiments were performed for patients with various age and pigment diseases; finally, some influencing factors and relevant solutions are enumerated and discussed.