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     

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.     

Preparation of Y2Ba4Cu7O15-δ Superconductor without High Oxygen Pressure

The synthesis of bulk Y₂Ba₄Cu₇O_15-δ superconductor at atmospheric oxygen pressure via solid state sintering is reported. Temperature ranging from 860 to 890 °C as well as time interval over 2 to 15 days were used to investigate the formation of the Y₂Ba₄Cu₇O_15-δ phase. A time-temperature profile characterizing the conditions for the preparation of Y₂Ba₄Cu₇O_15-δ phase suggests the optimal condition to be sintering at 890 °C for over 10 days. Detailed results of X-ray diffraction, electrical resistivity, iodometric titration and magnetization measurements are described.     

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;…     

A Novel Preparation of 2,4-Disubstituted Quinolines Catalyzed by FeCl3 ·6H2O in Ionic Liquids

Quinolines and their derivatives occur in numerous natural products. Many quinolines display interesting physi ological activities and have found attractive applications as pharmaceuticals and agrochemicals as well as being general synthetic building blocks. [1] Many synthetic methods have been developed for quinolines, [2] but due to their great importance, the development of novel synthetic methods remains an active research area. [3]     

Potential energy surfaces for HenNe+ ions: ab initio and diatomics-in-molecule results

The potential energy surface of He2Ne+ has been reinvestigated using a combination of ab initio and diatomics-in-molecule (DIM) calculations. In contrast to the reports of two recent studies the ion is found to have an asymmetric linear He-Ne-He structure, with no barrier to formation from the separated atoms on the ground-state surface. The He-Ne+ bond lengths at the potential minimum are 1.51 and 1.81 A, and the total bonding energy is 0.717 eV. Comparing the He2Ne+ energy to that of HeNe+, the bonding energy for the second helium atom is 0.06 eV, about 10% of that of the first He atom. The saddle point between the two equivalent minima is a symmetric structure, 0.0074 eV above the potential minimum. A symmetric geometry becomes the overall potential minimum if the 2s hole on the Ne is excluded from the reference states of a multireference configuration interaction calculation. A DIM potential was created for the HenNe+ family of ions. The DIM potential is consistent with the asymmetric He2Ne+ ion serving as a core; it predicts a slightly more asymmetric geometry than the ab initio results. Additional helium atoms form five-membered rings around the bonds of the core ion to fill the first shell and then add to the ends of the cluster. The asymmetric core ion and the highly compact structure help to account for the lack of apparent shell structure in the mass spectrometry of HenNe+ clusters. Finally, we recommend that the value De=0.63+/-0.04 eV be adopted for the ground state of HeNe+.     

我国区域绿色技术创新效率的分类测度和提升模式研究——基于非期望产出的SBM-SupSBM模型

本文首先运用考虑非期望产出的SBM-SupSBM模型估计我国各省市绿色技术创新效率并进行分类:稳定上升类、平稳类、大幅度波动类以及下降类。之后从企业内部和外部两方面对绿色技术创新效率提升的影响因素提出假设,着重考虑大幅度波动类别省份的效率提升。运用面板数据模型各影响因素进行验证,结论显示:企业规模对绿色技术创新效率波动较大的省份起到显著的抑制作用,环境规制和技术进步对绿色技术创新效率波动较大的省份作用不明显。针对分析结果,提出结论:在提升绿色技术创新效率的过程中,应注重企业规模和技术进步的协同作用,以及技术的开放程度。     

Novel Phenomenon of Oxygen-to-oxygen Silyl Migration in Directed Aldol Reaction

The phenomenon of migration of the silyl groups from α-oxygen to β-oxygen in sodium aldol reaction was observed for the first time in this paper.     

Study of the Fluorescence System of Europium–Enoxacin and its Applications

 This paper is the study of the fluorescence enhancement of Eu³⁺-1-ethyl-6-fluoro-4-oxo-7-(1-piperazinyl)-1,8-naphthyridin-3-carbonic acid (enoxacin, EFLX) system by surfactants. It was found that sodium dodecylbenzenesulfonate (SDBS) exhibits great enhancement on the fluorescence of the Eu-EFLX system. The molar ratio is 1:2:1 for Eu:EFLX: SDBS. Under the optimum conditions, the fluorescence intensity is a linear function of europium in the range of 1.0 × 10⁻⁸ ∼ 5.0 × 10⁻⁶ mol/L, the detection limit is 1.0 × 10⁻⁹ mol/L. The application of the Eu-EFLX-SDBS system for the determination of trace europium in rare earth samples gave satisfactory results. Received October 19, 2000. Revision August 10, 2001.     

A New Chemiluminescence Amplification Reaction for the Determination of HRP and Labelled HRP

A new chemiluminescence amplification reaction has been developed, which is on the coupling of the oxidation of Eosin by hydrogen peroxide under the catalysis of HRP at pH 3. 5 to the chemiluminescent reaction of luminol and hydrogen peroxide catalyzed by HRP at pH 10 to measure the activity of HRP and labelled-HRP. The detection limit of HRP is 10-10 g/mL. The lowest dilution ratio of HBsAb-HRP is 1 : 1. 8×102 and 1 : 106 for the direct method and coupled method respectively.