Synthesis,characterization and in vitro cytotoxicity screening of some triarylbismuth(V) di(N‐salicylidene)amino carboxylates and the crystal structure of (2‐HOC6H4CHNCH2CO2)2Bi(C6H5)3

Four novel triarylbismuth(V) di(N‐salicylidene)amino carboxylates were synthesized. Their structures were confirmed by IR, ¹H NMR, ¹³C NMR and elemental analysis. The crystal structure of (2‐HOC₆H₄CH?NCH₂CO₂)₂BiPh₃ was determined by X‐ray diffraction. The in vitro cytotoxicity of all compounds against three human cancer cells (HL‐60, BGC‐823 and MDA‐MB‐435) at 10 µM are reported. Copyright © 2005 John Wiley & Sons, Ltd.     

Field analysis of a general chiral planar waveguide

The propagation characteristics of general chiral planar waveguides are presented. This is the first time the eigen equation is given in a simple formulation. The results indicate that there are two types of field distribution which is related to the working wavelength and chiral admittance. When the chiral admittance is larger than a certain value, the fields of one kind of circularly polarized wave in the core become exponentially damping in the transverse direction. This work was supported by the “Foundations for the Ph.D Programs of China”     

聚苯乙烯—吡啶树脂的合成及催化水解反应

在氢氧化钠作用下，氯甲基化聚苯乙烯与吡啶反应制成聚苯乙烯－吡啶树脂，测定了其化学组成和红外光谱，并考察了在酯水解反应中的催化活性。     

Analytical removal of singularity and direct evaluation of singular integrals in 3-D elastoplastic finite deformation analysis by BEM

As a further development of the present authors' research work [1,2], in this paper a method of the so-called quadratic pentahedron polar co-ordinate transformation and analytical removal of singularity of Cauchy principal value singular integrals is proposed to evaluate the strongly singular integrals in the sense of Cauchy principal values and the weakly singular integrals over quadratic internal cells in 3-D elastoplastic finite deformation analysis by BEM. First, a quadratic pentahedron polar co-ordinate transformation technique is used to reduce the order of singularity of the singular integrals. Then, a form of Gauss' theorem is introduced to remove the singularity in the Cauchy principal value singular integrals analytically. Therefore, the evaluation of all those strongly and weakly singular integrals can be carried out by standard Gaussian quadrature accurately and efficiently. Numerical examples of the 3-D elastoplastic problem and 3-D finite deformation problem are given to demonstrate that the method possesses good accuracy and numerical stability, and is convenient to implement. The method in this paper can be applied extensively to evaluating the singular integrals over cubic and higher order elements.     

高亮度搪瓷交流电致发光屏的研究

本文报导了通过改进珐琅介质的介电性能,并采用特殊的灼烧工艺,获得高亮度.长寿命的搪瓷交流电致发光(AC—EL)屏的方法。     

Properties of TRPO-HNO_3 complex used for direct dissolution of lanthanide and actinide oxides in supercritical fluid CO_2

The mixed trialkylphosphine oxide-nitric acid (TRPO-HNO3) complex prepared by contacting pure TRPO with concentrated HNO3 may be used as additives for direct dissolution of lanthanide and actinide ox- ides in the supercritical fluid carbon dioxide (SCF-CO2). Properties of the TRPO-HNO3 complex have been studied. Experimental results show when the initial HNO3/TRPO volume ratio is varied from 1:7 to 5:1, the concentration of HNO3 in the TRPO-HNO3 complex changes from 2.12 to 6.16 mol/L, the [HNO3]/[TRPO] ratio of the TRPO-HNO3 complex changes from 0.93 to 3.38, and the content of H2O in the TRPO-HNO3 complex changes from 0.97% to 2.70%. All of the density, viscosity and surface tension of the TRPO-HNO3 complex change with the concentration of HNO3 in the complex. The protons of HNO3 and H2O in the complex undergo rapid exchange to exhibit a singlet resonance peak in NMR spectra with D2O insert. When the TRPO-HNO3 complex dissolves in a low dielectric constant solvent, small droplets of HNO3 appear which can be detected by NMR.     

灯泵浦激光器输出激光稳定性实验研究

分析了灯泵浦激光器的特点以及影响其输出激光稳定性的原因,提出了在激光器谐振腔内加一个“Q开关”的方法来控制输出激光的稳定性,以氙灯泵浦的被动锁模Nd:YAG激光器为例进行了实验研究,证实了此方案是可行的.     

Tribological performance and thermal behavior of epoxy resin nanocomposites containing polyurethane and organoclay

A series of epoxy resin nanocomposites modified by polyurethane and organically modified montmorillonite was prepared by effectively dispersing the organically modified montmorillonite in interpenetrating polymer networks (IPNs) of epoxy and polyurethane via the sequential polymeric technique and in situ polymerization. The tribological performance of the resultant EP/PU nanocomposites was investigated by a pin‐on‐disc tester, and the results showed that adding polyurethane and organically modified clay to the EP matrix had a synergistic effect on improving tribological performance of EP/PU nanocomposites. The morphologies of the worn surface were studied by scanning electron microscopy (SEM) observations, and the results indicated that the mechanism of improving tribological performance of EP/PU nanocomposites was different from that of pure EP or pure EP/PU IPNs. The thermal behavior of these nanocomposites was also investigated by thermogravimeric analysis (TGA), and the results indicated that adding organically modified clay to the matrix remedied the deterioration of the thermal degradation temperature of the interpenetrating networks. Copyright © 2008 John Wiley & Sons, Ltd.     

A Mild and Efficient Method for N‐Arylnucleobase Synthesis via the Cross‐Coupling Reactions of Nucleobases with Arylboronic Acids Catalyzed by Simple Copper Salts

A simple and efficient copper‐salt catalyzed N‐arylation of nucleobases is reported. In a mixed solvent of MeOH and H₂O, the coupling products were obtained in moderate to excellent yields at room temperature within a short time. A variety of substituted N‐aryl nucleobases can be prepared through this procedure.