Nonlinear stability of circular vortex patches

This paper proves that circular vortex patches in the plane are stable for the nonlinear dynamical system generated by the Euler equations of incompressible fluids. This is achieved by establishing a relative variational principle in terms of either energy or angular momentum. Thus, we exploit and extend Arnold's idea in (1965, 1969) to a nonsmooth setting as well.Research partially supported by DOE contract DE-AT03-82ER12097 to the University of California, Berkeley     

大鼠脑组织中不同部位单胺类神经递质含量的HPLC测定

单胺类神经递质,多巴胺(DA)、去甲肾上腺素(NA)和肾上腺素(A)是哺乳动物和人类中枢重要的信息传递物质。了解脑组织中各部位单胺类神经递质的含量对于研究其生理功能、有关疾病的诊断和药物及手术疗效的评价均有重要的意义。     

具有生物活性的有机磷化合物的研究V，α－［（取代）芳氧基乙酰氧基］烷基膦酸酯的合成和性质

过取代苯氧乙酰氯和α－羟基烷基胰酸酯的缩合反应合成了８种标题化合物，用元素分析，红外，核磁及质谱作了表征，测定了它们的除草活性和植物生长调节活性。     

MoO_3、NiO、ZnO在小表面金红石上的分散行为

氧化物、盐类在氧化物载体表面的自发分散是一种广泛存在的现象，文献中已报导过大量氧化物和盐类在高比表面载体上分散的研究结果［'－3］TIO。作为一种较新型的载体，与Y－AI。O。、硅胶等传统载体相比，有许多不同特性．活性组分在TIO。表面的分散状态及所得催化剂的性能已有不少报导［'－'］，但所用的TIOZ主要是较高比表面的锐钛矿型TIOZ（刘金红石型TIO。（r）和锐钛矿型TIOZ（a）的结构不同，它是高温生成相，比表面较小［'］．氧化物在金红石上的分散行为仍未见报导．我们制备了三种具有不同比表面的TIO水），系统地研…     

酚氧桥联的不对称双铜(Ⅱ)和铜(Ⅱ)-锌(Ⅱ)配合物的合成和磁性

本文合成了一组新的不对称双核配合物「Cu(samen)Cu(terp)」和「Cu(samen)Zn(terp)」,samen~4和terp分别表示N N’-乙二水杨酰胺胺根阴离子和2.2′:6′2″-联三吡啶。配合物「Cu(samen)Cu(terp)」的变温磁化率已测,其数值用最小二乘法与Bleancy-Bowers方程拟合,求得交换积分J=-0.538cm~(-1),表明配合物中铜离子间有极弱的反铁磁自旋交换作用。     

A time dependent density functional theory study of alpha-84 phycocyanobilin chromophore in C-phycocyanin

The optical characteristics of absorption and circular dichroism (CD) spectroscopy of an alpha-subunit of C-phycocyanin (C-PC) were investigated by using time dependent density functional theory (TDDFT) combined with the polarizable continuum model (PCM). When the protonation of alpha-84 phycocyanobilin (PCB) and its interaction with the protein moiety in C-PC have been taken into account, satisfactory assignment of the absorption and CD spectra of alpha-84 PCB can be achieved. The TDDFT-PCM calculations conclude that in the visible absorption region the main peak arises from the pi electron excitation of the pyrrole rings and the shoulder peak comes from the charge transfer from Asp87 (a nearby amino acid residue) to PCBH(+).     

一种非晶硅膜改性弹性玻璃毛细管交联中等极性固定相色谱柱的制备

研究了非晶硅膜改性的弹性玻璃毛细管交联ＯＶ－１７０１中等极性固定相色谱柱。在适当温度下，采用过氧化二异丙苯（ＤＣＵＰ）游离基引发交联ＯＶ－１７０１固定液，成功地制备了交联ＯＶ－１７０１柱，该柱具有柱效高、惰性好、耐溶剂、抗腐蚀和耐高温等性能，是一种新型高性能的中等极性交联柱。     

Gel routes to environmental catalysts

Various methods for the preparation of metal oxide catalysts for environmental control purposes are described. These include coprecipitation, sol-gel, and impregnation, and are used to prepare mixed oxide catalysts of the types SnO₂-MO₂ (M=Ce or Zr), SnO₂-Ln₂O₃ (Ln = lanthanide), Ln-doped CeO₂, Cr (VI)-doped SnO₂, and Cu(II)-doped SnO₂. The aggregation in stable colloidal sols of SnO₂, CeO₂ and ZrO₂ is dependent on the concentration of the metal oxide. Techniques for the characterisation of these catalyst materials include gas adsorption, X-ray diffraction, and TEM/EDXA.     

Application of capillary electrophoresis to process monitoring in the manufacturing of semisynthetic penicillins

Application of capillary electrophoresis to monitoring the concentration of material penicillin and the intermediates in the manufacturing process of semisynthetic penicillins was investigated. Factors affecting the precision of analysis were screened and optimised by orthogonal array designs. Compared to conventional HPLC methods, the capillary electrophoresis method gives better resolution and faster sample throughput. Other advantages of the capillary electrophoresis method over HPLC methods include much less consumption of buffer solution and the absence of organic solvents in the analysis.