Reliable quantitative detection of uric acid in urine by surface-enhanced Raman spectroscopy with endogenous internal standard.

Abnormal levels of uric acid (UA) in urine serve as warning signs for gout and metabolic cardiovascular diseases, necessitating the monitoring of UA levels for early prevention. However, the current analytical methods employed suffer from limitations in terms of inadequate suitability for home-based applications and the requirement of non-invasive procedures. In this approach, creatinine, a metabolite with a constant excretion rate, was incorporated as an endogenous internal standard (e-IS) for calibration, presenting a rapid, pretreatment-free, and accurate strategy for quantitative determination of UA concentrations.

[Automatic Field Calibration and Analysis of Satellite Based on Hyper-Spectral Ratio Radiometer].

With the demand of calibration technology of high frequency and high precision in terms of the optical remote sensing satellite of China, and the deficiency of the artificial work, the automatic system of hyper-spectral ratio radiometer was developed by investigation the calibration situation of domestic and abroad satellite, then the automatic calibration of satellite sensor was carried out. According to the parameters demand of field calibration and the goal of automation, the ratio radiometer was designed to measure global spectral irradiance by integrating sphere, and the diffuse spectral irradiance was measure by the shelter, so the diffuse-global ratio was calculated by these data. Simultaneity the ground radiation was measured with radiometer optical-lens and the automatic observation of atmospheric and surface radiation characteristics was achieved, In addition, the data pre-processing of real-time and remote transmission were integrated in the system.

[Stokes Parameter Detection and Precision Analysis Based on Rotating Quarter-Wave Plate].

The accuracy of the calibration reference source polarization states directly influences the precision of the polarized optical remote sensor calibration, and thus affects the inversion accuracy of the characteristics of targets. In this paper, 870 nm horizontal linear polarized light has been chosen as the tested calibration reference light, modulated by rotating quarter-wave plate(QWP). The intensity as a Fourier series of the rotation angle of the plate and its coefficients were demodulated with the Fourier transform method, Stokes parameters can be calculated with these coefficients.

[Research on the Distribution of Broad-Band Correlated Photon Spectra and the Measurement of Time-Correlation].

The correlated photon technique makes it possible to achieve a radiation calibration processing without chain transferring. The study of the spectral radiation character and time correlation of the photon is of great significance for broad-band radiometric calibration. To absolutely calibrate quantum efficiency of photoelectric detector, it is necessary to extend calibration band from single band to more bands.

Alignment error analysis of the snapshot imaging polarimeter.

A snapshot imaging polarimeter (SIP) system is able to reconstruct two-dimensional spatial polarization information through a single interferogram. In this system, the alignment errors of the half-wave plate (HWP) and the analyzer have a predominant impact on the accuracies of reconstructed complete Stokes parameters. A theoretical model for analyzing the alignment errors in the SIP system is presented in this paper.

[Spectral scanning measurement of high-precision solar irradiance-meter].

In order to measure the radiation of the sun absolutely and retrieve the characterization of the atmosphere precisely, a high-precision solar spectral irradiance meter working in 0.4-1.0 microm band was developed.

[Research on absolute calibration of sun channel of sun photometer using laser raster scanning method].

In the present paper, a new calibration method of absolute spectral irradiance responsivity of sun channel of sun photometer was developed. A tunable laser was used as source and a standard tranfer detector, calibrated against cryogenic absolute radiometer, was used to measure laser beam power. By raster scanning of a single collimated laser beam to generate the uniform irradiance field at the plane of effective aperture stop of sun photometer, the absolute irradiance responsivity of center wavelength of the 870 nm unpolarized sun channels of sun photometer was obtained accurately.