Biomedical subjects

Cun-zhou Zhang

Publications and source records attributed to Cun-zhou Zhang.

6 recordsLinked to original sources

PubMed2006

[The measurement of the ratio of primary hydroxyl group to second hydroxyl group in polyether polyol by near infrared spectrum].

The method of near infrared spectrum, combined with derivative spectrum and multiple linear regression was applied to measure the ratio of primary hydroxyl group to second hydroxyl group in polyether polyol. The authors obtained good predictive results by using the method in this experiment. The work is very helpful for the on-line measurement of polyether polyol.

English Abstract↗

PubMed2006

[The three-dimension spectral subtraction fluorescence to check adulteration of diesel oil by 120# solvent naphtha].

The characteristics of a adulterated sample of diesel oil by 120# solvent naphtha were studied with three-dimension spectral subtraction fluorescence technique, and it is shown that the technique could determine quickly whether there is a adulterated sample of 120# solvent naphtha in diesel. At the same time, by measuring the volume of three-dimension spectral subtraction fluorescence graph, the authors found that this total volume is directly related to the concentration of the adulterant present in the sample. The study is important for us to analyse whether there is a adulterated sample of 120# solvent naphtha in diesel, and is of significance for us to maintain the stability of market.

English Abstract↗

PubMed2006

[Study of poly (3,4-ethylene dioxythiophene) : poly (styrene sulfonate) by in-situ resonance Raman spectroscopy].

Poly (3,4-ethylene dioxythiophene) (PEDOT): Poly (styrene sulfonate) (PSS) has attracted a lot of interest for application in organic electronics due to good stability and high electronic conductivity in its doped state. Indeed, thin layers of PEDOT:PSS was regularly used in light emitting diodes (PLEDs) as hole injection and transportation layer. Here, Doping and dedoping states of PEDOT:PSS were studied by absorbance spectra and Raman spectra. A new absorption band centered at 620 nm was observed on dedoped PEDOT:PSS. Consistently, Raman signals of dedoped PEDOT:PSS are resonantly intensified since the Raman excitation wavelength (633 nm) is set in the enhanced absorption band. So it gives a sensitive way to study the doping and dedoping states of PEDOT:PSS. Furthermore, for the encapsulated polymer light-emitting diodes, Raman spectroscopy is a powerful way to study the polymer layers inside the devices.

English Abstract↗

PubMed2004

[Study on the degradation of polymer light-emitting diodes by in-situ micro-Raman spectroscopy].

The authors report Raman degradation study of polymer light-emitting devices under ambient conditions. In order to investigate the chemical degradation reaction in polymer light-emitting diode (PLEDs) devices, the chemical structure of the poly (2-(4-Ethylhexyl) phenyl-1, 4-phenylene vinylene) (P-PPV) polymer was analyzed by micro-Raman spectroscopy during the lifetime of the devices. The evidence for the reduction of conjugation length is provided by Raman spectroscopy. This reduction of theconjugation length, which dramatically increases the resistance and cuts off the current density, was the main reason for the failure of lighting. These findings provide an important insight into the intrinsic degradation mechanisms of the polymer LEDs and help in the development of even more stable devices.

Electrochemistry↗

PubMed2004

[Adopting the method of principal components analysis combined with correlation coefficient to increase the predicted concentration's accuracy of benzene and its homology mixture].

The concentrations of benzene and its homology mixture were measured by near infrared spectra, and the emphasis was put on the character of the principal component and its physical significance. It is pointed out that the anterior principal components are very similar to the correlation coefficient of the multi-component solution and the theoretical proof for the right condition is given. The high frequency noise of the system can be checked out by principal component combined with the correlation coefficient. Removing the noise can greatly increase the accuracy of the prediction model.

Benzene↗

PubMed2002

[Research of image spectrometer using linear variable interference filter].

In the present work we have designed a small-size portable imaging spectrometer using linear variable interference filter, with CCD camera as picture sensor, and micromotion stage to bring along interference filter which scan across every pixel of CCD array. The difference column pixel in the picture which we get at every step is monocolour partial image under different wavelength, with the step by step, these column monocolour pixels change the wavelength. And finally we reassembled these images and get the whole monocolour image with different wavelength. The interval of sweep step length decided by the required spectrum resolution and the required wavelength interval of different pictures. The experiment demonstrated the resolution of this spectrometer is about 16 nm, but that major reason of the limiting resolution is the band width of the linear variable interference filter. The spatial resolution of the instrument ultimately decided by CCD, filter and imaging lens. This spectrometer has some characters such as compact structure, higher spatial resolution, higher spectrum resolution, higher scan rate and so on. Furthermore, an application of this instrument in distinguishing from camouflage have been showed.

Analog-Digital Conversion↗