MAIN FACTORS IN PREPARATION OF ANTIBACTERIAL PARTICLES／PVC COMPOSITE

Zirconium phosphate containing silver was chosen as antibacterial particles in preparing antibacterial particles/PVC composite. The effect of surface property of the antibacterial particles and of their filler content on the properties of antibacterial particles/PVC composite was studied. The effect of the interracial compatibility on mechanical properties of the composite was also discussed. Experimental results showed that the antibacterial PVC composite had good antibacterial property, reaching almost 100% bacteriostatic level at an antibacterial powder filler content of 1.5phr.     

核科学中的世纪女杰

在20世纪的核物理领域中出现了四位令人瞩目的女科学家,除了我们所熟悉的居里夫人、吴键雄之外,还有奥地利物理学家丽丝·迈特纳和美国物理学家玛丽亚·梅耶.她们都堪称核科学中的巾帼英雄,对核科学的发展起了巨大的推动作用.     

Individual eye model based on wavefront aberration

Based on the widely used Gullstrand-Le Grand eye model, the individual human eye model has been established here, which has individual corneal data, anterior chamber depth and the eyeball depth. Furthermore, the foremost thing is that the wavefront aberration calculated from the individual eye model is equal to the eye's wavefront aberration measured with the Hartmann-shack wavefront sensor. There are four main steps to build the model. Firstly, the corneal topography instrument was used to measure the corneal surfaces and depth. And in order to input cornea into the optical model, high-order aspheric surface-Zernike Fringe Sag surface was chosen to fit the corneal surfaces. Secondly, the Hartmann-shack wavefront sensor, which can offer the Zernike polynomials to describe the wavefront aberration, was built to measure the wavefront aberration of the eye. Thirdly, the eye's axial lengths among every part were measured with A-ultrasonic technology. Then the data were input into the optical design software–ZEMAX and the crystalline lens's shapes were optimized with the aberration as the merit function. The individual eye model, which has the same wavefront aberrations with the real eye, is established.     

Fabrication and direct bonding of photosensitive multicomponent silicate glasses for lossless planar waveguide splitters

In this paper the fabrication, characterization, and thermal assisted bonding of two photosensitive silicate glasses is presented, as part of a wider process aiming to obtain a planar waveguide lossless splitter for telecom applications. Two glass compositions are investigated: an Er–Yb doped silicate glass, which amplifies the signals when pumped at 980 μm and a matchable passive glass, which is designed to host the waveguide splitter. The two parts were bonded successfully using direct bonding technique at 605 ± 20 °C for 240 min under a pressure of 28 kPa. Vickers hardness measurements were made on the bulk glasses and at the bonded interface, which showed no cracks propagating along the interface.     

Computational studies on amino-type excited-state intramolecular proton transfer and subsequent cis–trans isomerisation reactions of three 2-(2'-aminophenyl)benzothiazole derivatives

Excited-state intramolecular proton transfer (ESIPT) reactions of three amino-type 2-(2'-aminophenyl)benzothiazole (PBT-NH₂) derivatives, that is, 2-(2'-methylaminophenyl)benzothiazole (PBT-NHMe), 2-(2'-acetylaminophenyl)benzothiazole (PBT-NHAc) and 2-(2'-tosylaminophenyl)benzothiazole (PBT-NHTs), have been explored by the time-dependent density functional theory (TD-DFT) method with the B3LYP density functional. In addition, their absorption and fluorescence spectra were also simulated at the same theoretical level. The present studies reveal that the energy barriers of the first singlet excited state of the three titled compounds along the ESIPT reactions are predicted at 0.39, 0.30 and 0.12 eV, respectively, suggesting that the inclusion of a strong electron-withdrawing tosyl group can remarkably facilitate the occurrence of the ESIPT reaction, while the involvement of an electron-donating methyl group has no effect on the ESIPT process of the amino-type hydrogen-bonding system. Following the ESIPT, both PBT-NHAc and PBT-NHTs molecules can also undergo the cis–trans isomerisation reactions along the C₂–C₃ bond between benzothiazole and phenyl moieties, in which the energy barriers of the trans-tautomer → cis-tautomer isomerisations in both ground states are calculated at 0.33 and 0.27 eV, respectively. This implies that there may exist a long-lived trans-tautomer species in the ground states for PBT-NHAc and PBT-NHTs, as observed in the spectroscopic experiments of PBT-NHTs.     

Air Oxidation of Benzoin Catalyzed by Metal-Salen Complexes

Metal-Salen (M = Fe, Co, Ni, Cu, Zn) complexes were synthesized to catalyze the oxidation of benzoin to benzil with air as the “green” oxidizing reagent. The effects of temperature, base and solvent on M-Salen catalyzed oxidation of benzoin had been examined and optimized. The catalysis results showed that Co-Salen and Fe-Salen complexes were efficient to catalyze the oxidation reaction with yields over 80% while the catalytic activities of other three M-Salen complexes were poor. Moreover, the Co-Salen catalysis system could be reused three times with satisfied yield.     

非线性动力学方程的精细积分算法

介绍用精细积分法求解动力学问题的原则和方法,通过实例证明用这种方法求非线性问题数值解的有效性．