[Piezoresistivity of ultra-thin poly-silicon layer by aluminum-induced layer exchange].

Poly-Si film, due to its favorable piezoresistive properties, has been widely used in piezoresistive sensors. The previous researches have shown that the ultra-thin poly-Si film have better piezoresistive properties than common poly-silicon film, and have promising future of application. A promising method to obtain large grained high quality poly-silicon films by low-temperature crystallization of an amorphous precursor material is the aluminum-induced layer exchange (ALILE). In this paper, ultra-thin poly-Si films were prepared by aluminum induced layer exchange (ALILE). Experimental results of Raman spectroscopy show that a narrow and symmetrical Raman peak at the wave number of about 518 cm(-1) was observed for all samples, indicating that the films were fully crystallized. XRD results show that the crystallites of ultra-thin poly-silicon layer were preferably (111) and (220) oriented. Hall affect measurements show that hole concentration of the films (p-type) were between 9 x 10(18) and 6 x 10(19) cm(-3). Restorative properties show that the piezoresistors exhibit gauge factors (GFs) up to 60, with temperature coefficients of GF (TCGF) between -0.17-0% degree C and temperature coefficients of resistance (TCR) between -0.2 and -0.1% degrees C. The study of the ultra-thin poly-Si films by ALILE is completed, and the study results lay a foundation for application of the film

[Preparation and characterization of poly-Si films on different topography substrates by AIC].

Polycrystalline silicon (poly-Si) thin-films were made on planar and textured glass substrates by aluminum-induced crystallization (AIC) of in situ amorphous silicon (a-Si) deposited by DC-magnetron. The poly-Si films were characterized by Raman spectroscopy, X-ray diffraction (XRD) and atomic force microscopy (AFM). A narrow and symmetrical Ranman peak at the wave number of about 521 cm(-1) was observed for all samples, indicating that the films were fully crystallized. XRD results show that the crystallites in the authors' AIC poly-Si films were preferably (111) oriented. The measurement of full width at half maximum (FWHW) of (111) XRD peaks showed that the quality of the films was affected by the a-Si deposition temperature and the surface morphology of the glass substrates. It is likely that an a-Si deposition temperature of 200 degrees C seems to be ideal for the preparation of poly-Si films by AIC.

[Quantitative determination of imidacloprid by infrared absorption spectrometry].

The content of imidacloprid in pesticide is usually measured by high-performance liquid chromatography, which is precise but time-consuming. In the present work the content of imidacloprid in pesticide was measured by infrared spectroscopy with pressing potassium bromide troche (KBr). A comparison of infrared spectra between analytic imidacloprid and commercial pesticide showed that the absorption peak of imidacloprid at 939.2 cm(-1) is independent and can be used as the characteristic absorption peak for quantitative determination. The area from 947 to 925.8 cm(-1) for the infrared spectra of imidacloprid and its content meet the linear equation: Area = l.3665 x 10(-1) + 2.37 x 10(-2) x c, r = 0.99953. Finally, the authors could draw a conclusion that the method of NIR, instead of routine lab analysis, is feasible for the determination of imidacloprid in pesticide.

[Spectroscopy research on the origin mechanism for light induced delayed fluorescence of chloroplast].

Research of the mechanism for delayed fluorescence origin play an important role in the application of DF. Based onthe charge recombination theory, the mechanism for delayed fluorescence origin is theoretically analyzed in this paper. The decay kinetics of DF, depending on the backward transport electron and oxidized state P680+, can be well fitted by poly-exponent. The relative fast component of DF originates from the Z+ P680 Q(A)- states, generated during the previous period of the sample illumination. On the other hand, the slow component of DF is ascribed to the state Q(B)= --the next electron carrier of deoxidized side in PS II. Meanwhile, the experimental results confirmed the theoretical conclusion. Furthermore, the authors testified that the third component with lifetime much greater than the time of the registration period (which is presented as a constant), is corresponds to the recombination of P680+ and the backward transport electron from PSI.