Biomedical subjects

Zhi-yu Wen

Publications and source records attributed to Zhi-yu Wen.

5 recordsLinked to original sources

PubMed2006

[Application of fractal theory to spectral signal recognition].

The fractal theory is a discipline that studies a kind of irregular and chaotic object with similarity of its part and whole. The fractal dimension is a basic index mark of irregularity and self-similarity in the fractal theory. The present paper takes the spectral signal according with Lambert-beer' law as the object, introduces the basic theory of fractal geometry in brief, puts forward the method of fractal dimension as the feature of spectral signal recognition, makes use of reconstructing phase space to gain the fractal dimension of spectral signal, compares different values of the fractal dimension to recognize different spectral signal, and gives an example for explanation.

English Abstract↗

PubMed2006

[The project and simulation of a compositive miniature spectrum instrument based on the array of Fabry-Perot cavity].

This paper advances a kind of micro-spectrometer based on Fabry-Perot cavity's character of filtering the waves. The basic structure of the micro-spectrometer is the array of Fabry-Perot cavity which contains many different lengths of cavity on the substrate of silicon, consequently the authors can achieve the detection at several wavelengths simultaneously. The unit of probing is a Fabry-Perot cavity made up of the substrate of silicon-metal film-silicon dioxide layer-metal film. The authors carried out the corresponding simulation. In the basic structure of aluminum film(14 nm)-silicon dioxide layer-silver film(39 nm), the resolution can reach 15 nm. When the area of a unit of probing is 0.14 mm x 0.14 mm only, it can reach the luminous flux of miniature grating spectrum instrument (the minimum volume in the order of cm), but the volume of the part of spectrum detection is only of the order of mm. The design size of the micro-spectrometer is a few millimeters. Furthermore it has no movable parts and could detect several wavelengths at the same time. It is possible to fabricate such micro-spectrometer through existing processing methods of IC technology.

English Abstract↗

PubMed2005

[Reducing the influence non-linearity of detecting array on absorption spectrum with curve fitting].

In a micro spectral analytical system, the non-linearity response of the photoelectronic detecting array pixel will cause the deformation of the spectrum, especially in the measurement of absorption spectrum. In this paper, the factors that cause the deformation were studied and a corresponding solution was proposed to reduce such deformation. By using curve fitting, the non-linearity of the pixel can be corrected. This method was adopted to correct the absorption spectrum obtained by a micro spectral analytical system and the result showed that it is a efficient way to correct the non-linearity in the pixel of photoelectronic detecting array.

Algorithms↗

PubMed2005

[Experimental testing of micro biochemical analytical system].

A micro biochemical analytical system based on a micro fiber spectrometer is introduced. Experiment was carried out to calibrate and test the analysis system. In the experiment, the absorption spectra of Fe2+ -ferroin solution bodies with different concentrations were obtained. The working curve shows a fine linearity of the analysis system. The authors also compared the experimental results obtained from 722-spectrometer and those from our analysis system. It was shown that their system can meet the requirement of practical use. This system also has many advantages, such as real-time whole spectrum analyzing and small volume, and is an ideal instrument for biochemical analysis.

Chemistry Techniques, Analytical↗

PubMed2005

[Spectral signal recognition based on wavelet packet analysis].

Automated recognition of spectral signal is an importance part of spectral analysis, which jnvolves comparing spectral signals under the same conditions and obtaining relation of chemistry constitution according to similarity by pattern recognition method and computer technique, and is useful to determine the nature of spectral signal and validate spectral signal. This paper takes spectral signal according with Lambert-beer' law as object, introduces basic theory and method of recognition of spectral signal in brief, normalizes spectral signal to decrease difficulty, introduces wavelet analysis theory, puts forward the method of wavelet packet analysis to gain features of spectral signal, obtains formula to compute feature vector and error vector by statistics method, then makes use of binary tree' mode distinguishing step by step for quick recognition, and finally gives an example to explain.

Algorithms↗