High-risk factors for urinary calculus recurrence in Chinese preschool children: findings from a medium-term follow-up survey.

Background: To date, most literature has focused on factors contributing to the initial occurrence of pediatric urinary stones. However, there is scant literature on the risk factors for recurrence following the initial episode. Effective treatment strategies for the initial episode and measures to reduce the risk of stone recurrence are crucial.

[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.

[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.

[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.

[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.

[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.

[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.

[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.