双齿配体—1,2—C_6H_4SX(X=O,S)的钴化合物~1H NMR研究

以~1H NMR谱学和磁化率对一些含邻苯二硫酚或巯基苯酚配体的钴化合物的磁性作了研究,并讨论了它们的电子结构。     

关于正定可对称化线性代数方程组的预对称正则化算法

1引言考虑线性代数方程组A_x=b,A∈R~(n×n)非奇异,x,b∈R~n(1)的求解．当系数矩阵是大型稀疏的正定可对称化矩阵,文[1,2]讨论了一类预对称共轭梯度算法(LRSCG算法是其中之一),这类算法的实质是利用非对称的系数矩阵可对称化的性质,并结合共轭梯度法而构造的一种预处理的共轭梯度法[12,16,17]．但非对称的系数     

天然水源中微量铀钍含量与摄入量研究

分析了居民饮用水及其天然水源中微量铀，钍的含量，并与尿液中铀，钍含量进行了比较。结果表明，上海地区天然水源在国家规定的允许范围内，接近于尿液中铀，钍的日排出量。     

pH-responsive star-shaped functionalized poly(ethylene glycol)-b-poly(ε-caprolactone) with amino groups

Functional star-shaped 4-arm poly(ethylene glycol)-b-poly[(ε-caprolactone-co-γ-amino-ε-caprolactone)] (4-arm PEG-b-P(CL-co-ACL) was synthesized through ring-opening polymerization. The structure of the copolymer was confirmed by ¹H NMR, Fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography (GPC). To further understand the copolymers, the difference of the conversion rate between ε-caprolactone (CL) and γ-(carbamic acid benzyl ester)-ε-caprolactone (CABCL) and the detailed deprotection condition were studied. The thermal property of the copolymer was analyzed by WAXR and differential scanning calorimetry (DSC), which demonstrated that the thermal property could be well adjusted. The pH-responsive behavior of the copolymers was studied in detail by dynamic light scattering (DLS), pH titration, and pyrene fluorescence methods, which indicated that it could form micelles and exhibit pH responsibility. Moreover, the copolymer was nontoxic and had good biocompatibility according to the results by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay.     

Construction of diaminobenzoquinone imines via ferrocene-initiated radical reaction of benzoquinone with amines

A ferrocene-initiated radical reaction of benzoquinone with amines has been successfully developed for the direct access to diaminobenzoquinone imines in high yields,in which the comme rcially available and cheap ferrocene was employed as a radical initiator and TBHP was used as an oxidant.Moreover,this reaction could be achieved with low loading of ferrocene(0.5 mol%).This protocol is highly efficient with good substrate tolera nce and provides a new approach for the construction of benzoquinone imines with potential pharmaceutical interest.     

基于均匀化理论的多孔板弯曲问题新解

由于订型分布孔的存在,通常的有限元法不能有效地分析多孔板的弯曲问题。该文基于均匀化理论建立了该类问题的新解法。对含密集型分布的阶梯型圆孔板的分析结果,说明了该文方法是有效的。     

介质阻挡放电与 CuZSM-5 结合方式对脱除 NOx 的影响

 研究了介质阻挡放电 (DBD) 与 CuZSM-5 结合方式, 即 DBD 和 CuZSM-5 两段分置 (两段法) 或将 CuZSM-5 放入 DBD 区 (一段法), 对脱除氮氧化物的影响. 结果表明, 在 NO/N2 或 NO/C2H4/N2 无氧体系中, DBD 与 CuZSM-5 结合产生的协同效应很小; 在 NO/O2/N2 富氧体系中, DBD 与 CuZSM-5 结合导致氮氧化物转化率下降; 而在 NO/C2H4/O2 /N2 富氧体系中, 在 250 ºC, 空速 12 000 h1, 输入放电能量密度 (Ein) 155 J/L 的条件下, 单纯催化、单纯等离子体放电、一段法和两段法时氮氧化物转化率分别为 39%, 1.5%, 79% 和 52%. 两段法产生了中等程度的协同效应, 主要是第一段等离子体放电产生新稳态物种 (如 NO2, CO 和 CO2 等) 起作用; 而一段法产生的协同效应较大, 主要是由于等离子体放电产生的新稳态物种和激发态短寿命物种 (如 N2*, NO*, CH 和 CN 等) 共同起作用.     

Local convergence results of Gauss-Newton's like method in weak conditions

In this paper, we study the convergence of Gauss-Newton's like method for nonlinear least squares problems. Under the hypothesis that derivative satisfies some kind of weak Lipschitz condition, we obtain the sharp estimates of the radii of convergence ball of Gauss-Newton's like method and the uniqueness ball of the solution.     

Charge-separated-state enhancement of the third-order optical nonlinearity of a photosensitizer-electron acceptor triad assembly

′ ,4^′′,4^′′′-tetrasulfonato-phthalocyanine/N-butyl-N^′-methylanthraquinone-4,4^′-bipyridinum dibromide assembly (ZnTsPc-V-AQ), was observed to be enhanced by ten times when the sample was optically pumped by a 355 nm pump beam. The enhancement of the nonlinearity was found to be due predominantly to the charge transfer between the two monomers of the supramolecule after optical excitation. Received: 2 July 1996