Electric fields in an electrolyte solution near a strip of fixed potential

Electrostatic fields produced by flat electrodes are often used to manipulate particles in solution. To study the field produced by such an electrode, we consider the problem of an infinite strip of width 2a with imposed constant potential immersed in an electrolyte solution. Sufficiently close to the edge of the strip, the solution is determined by classical electrostatics and results in a field singularity. We examine two limiting cases, (a) when strip width a<1k, the Debye screening length, and (b) when strip width is much greater than the Debye screening length, a>1k. We present exact results for the two cases in the limit of small potentials where the Poisson-Boltzmann equation can be linearized. By drawing on an analogy with antiplane shear deformations of solids, and by employing the path-independent J integral of solid mechanics, we present a new method for determining the strength of the edge singularity. The strength of the singularity defines an exact near-field solution. In the far field the solution goes to that of a line of charge. The accuracy of the solution is demonstrated by comparison with the numerical solutions of the Poisson-Boltzmann equation using the finite element method.     

STUDIES ON THE PREPARATION OF ZINC-CONTAINING ACTIVATED CARBON FIBERS AND THEIR ANTIBACTERIAL ACTIVITY

1. INTRODUCTION Microbial pollution will bring about various problems in industry and other vital fields, such as causing decomposing of materials, harming people抯 health. In order to reduce these problems, new antibacterial materials have been demanded. Recently, much attention has been paid to inorganic materials including zinc oxide [1~4]. These inorganic antibacterial materials are now substituting for organic materials to avoid releasing noxious organic molecules harmful to humans;…     

正丁基黄原酸根合镉(Ⅱ)的合成和晶体结构

黄原酸配合物以及它们与各种路易斯碱反应的产物得到广泛的研究犤１～４犦。可溶性的黄原酸碱金属盐广泛用于汞、银、镉等金属的萃取分离犤５～７犦，并且这类盐对于汞中毒具有解毒作用犤８犦。E．D．Zelmon等犤９犦对过渡金属黄原酸配合物的非线性光学性质进行了研究。但迄今为止，对黄原酸镉配合物与路易斯碱的反应与结构研究较少。我们首先合成了一种配位聚合物犤Cd（S２CO－n－C４H９）２犦n晶体，然后利用吡啶与犤Cd（S２CO－n－C４H９）２犦n反应破坏其原有配位聚合物的结构，得到了犤Cd（C５H５N）２（S２CO－n－C４H９）…     

新生儿硬肿症危险因素分析

为探讨新生儿硬肿症发病的危险因素，以便有效地预防该病，以41例硬肿症新生儿为研究对象，并设疾病对照组，运用多元Logistic回归，对8项可疑因素进行了分析。结果表明，早产，低体重，窒息和感染， 毒最终进入方程（P＞0．05），且OR值均大于1，是硬肿症发病的危险因素。硬肿症是原发病的一个并发症和严重征兆。寒冷不是本地区硬肿症的常见病因。流动人口的新生儿是硬肿症的高危人群。加强围产期母婴保健，普及新法复苏，感染的预防和早期有效干预，早产，低体重儿和重新新生儿热能供给和维持内环境平衡是预防硬肿症的有效措施。     

氰基乙烯基苯胺衍生物的电化学行为

本文利用循环伏安法研究了电子给-受体模型化合物——氰基乙烯基苯胺衍生物的电化学行为,并对推电子取代基团—NH_2和—N(CH_3)_2与吸电子取代基团氰基乙烯基对化合物电化学行为的影响进行了较为详细的讨论.提出了这些化合物的电氧化态和电还原态的结构,通过分析比较叔、仲和伯自由基对化合物电化学行为的影响,探讨了电极反应机理.     

石墨烯负载高活性Pd催化剂对乙醇的电催化氧化

以石墨粉为原料, 采用Hummers法液相氧化合成了氧化石墨(GO), 然后用化学一步还原制得石墨烯负载钯催化剂. X射线衍射(XRD)、透射电镜(TEM)表征表明, Pd在石墨烯载体上有较好的分散度, 粒径为3-5 nm. 电化学活性面积(EASA)、循环伏安(CV)、计时电流(CA)和计时电位(CP)等电化学测试表明, 与传统Pd/Vulcan XC-72相比, Pd/石墨烯催化剂对碱性介质中乙醇电催化氧化的催化活性有了很大的提高.     

聚合物共混物脆韧转变性能研究 Ⅲ.分散相形态参数之间的关系

为了研究形态（特别是分散状态）对聚合物共混物韧性的影响，建立了准网络形态模型，定义了分散相分布系数（ξ，０＜ξ１），并给出其物理意义，推导了基体层厚度的计算公式，研究了形态参数的变化对基体层厚度的影响．对于常见的无规形态，ξ≈１．对于准网络形态，ξ＜１，并且不是常数．计算结果表明，减小ξ和分散相粒径及其分布、增大其体积分数有利于减小基体层厚度．从理论上证明了准网络形态比无规形态更有利于减小基体层厚度．     

Synthesis and Crystal Structure of N-cyclopropyl-9 -（3,4-dicholophenyl）- 1,2,3,4,5,6,7,8,9,10-decahydroacridine -1,8-dione under Microwave Irradiation

1 INTRODUCTION aryl or methyl group to the nitrogen atom of these compounds leads to enhanced activities of fluo- A lot of natural and synthetic compounds con- rescence[7, . Since the pyridine scaffold is included 8] taining acridine skeletons display interesting biolo- in decahydroacridine-1,8-dione, a question is whether gical and physical activities[1]. Acridinedione, for the same modification on the nitrogen atom of de- example, has been identified as antimalarial and cahydroacridine-1…     

不同构象铂(Ⅱ)配合物与G-肌动蛋白作用的光谱研究

The cyclohexamethylene-diamine squaric acid platinum(Ⅱ) complexs(R,R, S,S) binding to G-actin and the consquence conformation change were studied by N-(1-pyrenyl) maleimide(NPM) labeled fluorescence and intrinsic fluorescence. The binding and chemical kinetics were determined by fluorometry. The results showed that when R (Pt/actin molar ratio) was lower than 30, the Pt binded to G-actin strong binding sites(-SH), when R was larger than 30, the Pt binded to G-actin weaker binding sites. The consquence conformation changes were determined by CD. The CD results showed that R was smaller than 60, G-actin α-helix contents decreased slowly, R was larger than 60, G-actin conformation changed obviously. The reaction of R,R complex of platinum(Ⅱ) S,S complex of platinum(Ⅱ) with G-actin was similar to that of with S,S complex of platinum(Ⅱ).     

新型树状大分子核醚-四硅烷的合成

以季戊四醇为原料合成了一种新型树状大分子核--醚-四硅烷,可用于树状大分子构筑.通过季戊四醇(1)与溴丙烯的醚化反应得到四烯丙基醚2,然后在Pt催化作用下,2与硅氯仿通过硅氢化反应生成醚-四(三氯硅烷) 3(可直接与多种官能团反应生成树状大分子),3经过LiAlH4还原后得到目标产物醚-四硅烷4.通过IR, 1H NMR, 13C NMR对中间体和目标产物的结构进行了表征,并对产物的结构进行了讨论和确认.