晶格反演的嵌入原子法模型及其应用

讨论一种基于晶格反演的嵌入原子法模型 ,其特点是未知函数的参数化是对原子间对势和单原子电荷密度函数的晶格和 ,而不是对原子间对势和单个原子的电荷密度函数进行的 ,其最大优点在于待定参数可以用物理输入解析地表达出来 ,而不是像大多数埋入原子法模型中那样通过拟合来确定 .给出了它在计算点缺陷 (自间隙杂质和空位原子 )和晶体表面形成能方面的应用 .     

质子滴线区新的缓发质子先驱核121Ce

藉助核反应⁹²Mo(³²S ,3n)产生了未知的缓发质子先驱核¹²¹Ce ,并利用氦喷嘴快速带传输系统和“p-γ”符合方法对它进行了鉴别 .测定了¹²¹Ce的半衰期 ( 1.1±0 .1 )s,观测了它的β缓发质子能谱 ,粗略地估计了它的β缓发质子衰变道的分支比约为1% .首次观测了先驱核¹¹⁹Ba,¹²¹Ba和¹²²La经过β缓发衰变在“子核”中产生的低位能级到基态的γ 跃迁.     

Double‐hydrophilic block copolymer for encapsulation and two‐way pH change‐induced release of metalloporphyrins

A double hydrophilic block copolymer composed of poly(acrylic acid) (PAA) and poly(4‐vinyl pyridine) (P4VP) was obtained through hydrolysis of diblock copolymer of poly(tert‐butyl acrylate) (PtBA) and P4VP synthesized using atom transfer radical polymerization. Water‐soluble micelles with PAA core and P4VP corona were observed at low (acidic) pH, while micelles with P4VP core and PAA corona were formed at high (basic) pH. Two metalloporphyrins, zinc tetraphenylporphyrin (ZnTPP) and cobalt tetraphenylporphyrin (CoTPP), were used as model compounds to investigate the encapsulation of hydrophobic molecules by both types of micelles. UV–vis spectroscopic measurements indicate that micelles with P4VP core are able to entrap more ZnTPP and CoTPP as a result of the axial coordination between the transition metals and the pyridine groups. The study found that metalloporphyrins encapsulated by the micelles with PAA core could be released on pH increase, while those entrapped by the micelles with P4VP core could be released on pH decrease. This behavior originates from the two‐way pH change‐induced disruption of PAA‐b‐P4VP micelles. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1734–1744, 2006     

铁电体表面效应的唯象理论及其与横场Ising模型的关系

分析了铁电体横场Ising模型与Landau唯象理论的关系,得出了有表面的铁电体的Landau自由能表达式,指出原有的表达式中面积分部分仅含与极化平方成正比的项只在特殊情况下成立,一般情况下还应包含与极化四次方成正比的项.利用所得出的自由能表达式,计算了铁电薄膜自发极化和Curie温度与厚度的关系,使原先用唯象理论不能理解的一些实验现象得到了解释     

荧光猝灭法测定人发中微量锰

异丙肾上腺素在pH9.91的伯瑞坦 罗比森缓冲溶液中被MnO-4氧化,导致其荧光强度显著减弱。最大激发及发射波长为278nm和616nm,MnO-4浓度在0.01～0.64mg·L-1范围内,荧光强度与浓度呈良好线性关系。将其用于人发中微量锰的测定,得到满意的结果。     

Determination of inosine 5′-monophosphate and guanosine 5′-monophosphate in pig feed by capillary zone electrophoresis

A capillary zone clectrophoresis method was developed for the determination of IMP and GIMP, commonly used as flavor enhancers in poultry feed, in a real sample of complex composition. A baseline separation of inosine 5′-monophosphate and guanosine 5′-monophosphate was achieved within 10 min and the other components in the sample did not interfere with the separation. Quantitative results obtained from pig feed samples are presented. The separation conditions and experimental reproducibility are also discussed.     

Microwave-Assisted Soluble Polymer-supported Synthesis of Peptoids

Libraries of peptide-like compounds are attractive sources of binding agents for proteomics applications. The synthesis of oligomeric combinatorial libraries of peptidomimetics is usually more straightforward than the creation of large libraries of more "drug-like" molecules. Herein we report synthesis of peptoids on soluble high loading Noncross-linked polystyrene. The synthesis route consists of: (a) preparation "soluble wang resin" from non-crosslinked polystyrene and 4-hydroxybenzyl alcohol via ether linkage, (b) an esterification step performed by the addition of bromoacetyl bromide to "soluble wang resin" and (c) a nucleophilic displacement of bromide with a primary amine.     

Further explorations on bridged 1,2,4-trioxanes

Three new bicyclo[3.2.1]-type 1,2,4-trioxanes have been designed and synthesized. One of them demonstrates better tolerance of the intramolecular hemiketals to steric crowding in hydroperoxidation. The other represents a prototype for possible manipulation of the transient radicals generated in cleavage reactions. A new substitution pattern in the bridged system is explored through synthesis of the third molecule. The configurations of all stereogenic centers in the bridged system can be effectively controlled by the chirality of the allyl alcohol as illustrated by the enantioselective synthesis of the fourth molecule. Finally, similar bicyclo[3.3.1]-type 1,2,4-trioxanes are shown very difficult to be synthesized because of the involvement of a conformer with two substituents at axial positions at the same time.     

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;…