(1-x)PMN-xPT铁电致冷陶瓷的研究

概括介绍了铁电致冷基本原理，给出了三种电生热效应，即线性电生热效应、二次电生热效应和电场诱导一级相变型电生热效应的表达式，测量了(1-x)Pb(Mg_1/3 Nb_2/3 )O₃-xPbTiO₃［简记为(1-x)PMN-xPT］，当x=0.08, 0.10和0.25时在室温附近的电生热性能，分析了其电生热效应的起源.研究结果表明，(1-x)PMN-xPT铁电固溶体陶瓷在室温附近具有较大的电生热效应；该效应起源于电场诱导一级相变型电生热效应和线性电生热效应；该系列陶瓷可望用于室温附近多级铁电致冷. 关键词：     

Asymmetric Cyclopropanation Catalyzed by Four Stereoisomers of a Copper-(Schiff-base) Complex with Double Chiral Centers

Catalytic asymmetric cyclopropanation of diazoacetates with olefins has attracted much attention. Those catalysts containing various metals and optically active ligands have been employed for this reaction1,2. The first catalytic asymmetric cyclopropanation reaction was reported in 1966 by Nozaki et al.3. The author used the copper(II) complex 1 bearing a salicyladimine ligand as catalyst though with a low e.e. value of 6%. Aratani and his coworkers designed the copper-(Schiff-base) comp…     

LIMIT CYCLES AND BIFURCATION CURVES FOR THE QUADRATIC DIFFERENTIAL SYSTEM(III)_(m=0)HAVING THREE ANTI-SADDLES(II)

ＬＩＭＩＴＣＹＣＬＥＳＡＮＤＢＩＦＵＲＣＡＴＩＯＮＣＵＲＶＥＳＦＯＲＴＨＥＱＵＡＤＲＡＴＩＣＤＩＦＦＥＲＥＮＴＩＡＬＳＹＳＴＥＭ（ＩＩ）ｍ＝０ＨＡＶＩＮＧＴＨＲＥＥＡＮＴＩＳＡＤＤＬＥＳ（Ｉ）ＹＥＹＡＮＱＩＡＮＡｂｓｔｒａｃｔＡｓａｃｏｎｔｉ...     

基于电-化-热耦合理论对称双阴极固体氧化物燃料电池堆的电流与温度场数值模拟

本文基于电-化-热多场耦合理论,通过有限元方法建立了一个基于对称双阴极结构SOFC电堆单元的三维数值模型,研究了其电堆内部的电流密度分布和温度分布. 研究结果表明,气体流动方式以及集流方式影响了电解质上电流密度和温度分布：在气体进、出气口处有较大的电流密度分布;在气体共流模式下,电解质层温度分布却较均匀;在双阴极结构电池阴极侧的单一集流模式下,集流侧的电解质的平均电流密度高于另一侧.     

Synthesis and Crystal Structure of α-( N-Protected a mino)β- lactam Derivative of 1 ,5-Benzothiazepine

１　ＩＮＴＲＯＤＵＣＴＩＯＮＲｅｃｅｎｔｌｙ,ａｎｕｍｂｅｒｏｆｄｅｒｉｖａｔｉｖｅｓｏｆｂｅｎｚｏｔｈｉａｚｅｐｉｎｅｈａｖｅｂｅｅｎｐｒｅｐａｒｅｄａｎｄｓｔｕｄｉｅｄｆｏｒｔｈｅｉｒｐｈａｒｍａｃｏｌｏｇｉｃａｌａｃｔｉｖｉｔｉｅｓ〔１５〕．Ｉｎｏｕｒｐｒｅｖｉｏｕｓｗｏｒｋ,ｗｅｈａｖｅｉｎｃｏｒｐｏｒａｔｅｄｔｈｅβｌａｃｔａｍｒｉｎｇｉｎｔｏ１,５ｂｅｎｚｏｔｈｉａｚｅｐｉｎｅｂｙｒｅａｃｔｉｏｎｏｆ１,５ｂｅｎｚｏｔｈｉａｚｅｐｉｎｅｗｉｔｈｓｏｍｅａｃｙｌｃｈｌｏｒｉｄ…     

Synthesis and Crystal Structure of Dicesium trans Dicarbonatotetraaquomagnesium, Cs_2[Mg(CO_3)_2(H_2O)_4]

ＩｎｔｒｏｄｕｃｔｉｏｎＰｒｅｖｉｏｕｓｌｙ,ｗｅｒｅｐｏｒｔｅｄｔｈｅｃｒｙｓｔａｌｓｔｒｕｃｔｕｒｅｏｆＫ２［Ｎｉ（ＣＯ３）２（Ｈ２Ｏ）４］［１］,ｗｈｉｃｈｃｒｙｓｔａｌｌｉｚｅｄｉｎｔｈｅｂａｙｌｉｓｓｉｔｅｔｙｐｅｓｔｒｕｃｔｕｒｅａｎｄｗａｓｆｏｕｎｄｔｏｂｅｉｓｏｓｔｒｕｃｔｕｒａｌｗｉｔｈＫ２［Ｃｏ（ＣＯ３）２（Ｈ２Ｏ）４］［２］ａｎｄＫ２Ｍｇ（ＣＯ３）２·４Ｈ２Ｏ［３］．Ｉｎｏｒｄｅｒｔｏｓｙｓｔｅｍａｔｉｃａｌｌｙｉｎｖｅｓｔｉｇａｔｅｔｈｅｏｃｃｕｒｒｅｎｃｅｏｆｔｈｅｃｏ…     

三甲川菁染料敏化TiO2纳米 结构电极的光电化学

The photoelectrochemical behaviors of the TiO₂ nanostructured porous film sensitized by cyanine dye were investigated in this paper.The results showed that the excitaed state level matched the conduction band edge of TiO₂ nanoparticle.Therefore the sensitization of the dye can increase the photocurrent intensity of the TiO₂ nanostructured electrode obviously and results in a red-shift of optical absorption from the ultra-violet region to the visible.As a result,the light-to-electricity conversion efficiency was improved evidently,the maximum value of IPCE has reached 12.1%.     

A Fluorescence Optical Fiber Sensor for Amrinon Using a New Oxazole Compound

ＩｎｔｒｏｄｕｃｔｉｏｎＡｍｒｉｎｏｎ,ａｓｙｎｔｈｅｔｉｃｂｉｐｙｒｉｄｉｎｅｄｅｒｉｖａｔｉｖｅ,ｎｏｎｇｌｙｃｏｓｉｄｅａｎｄｎｏｎｃａｔｅｃｈｏｌａｍｉｎｅｃａｒ－ｄｉｏｔｏｎｉｃｓｔｉｍｕｌａｎｔ,ｉｓｃｕｒｒｅｎｔｌｙｕｓｅｄｉｎｔｈｅｔｒｅａｔｍｅｎｔｏｆｔｈｅｈｅａｒｔｆａｉｌｕｒｅａｎｄｆｏｒｃａｒｄｉｏｖａｓｃｕ－ｌａｒｓｕｐｐｏｒｔｉｎｐｅｄｉａｔｒｉｃｐａｔｉｅｎｔｓ．Ｉｔｐｏｓｓｅｓｓｅｓｐｏｔｅｎｔｃａｒｄｉａｃａｎｄｂｌｏｏｄｖｅｓｓｅｌｓｐｒｅａｄｉｎｇｅｆ－ｆｅ…     

Ni-Ge共掺杂下对AgSnO2触头材料性能的第一性原理分析

AgSnO₂触头材料是一种环保型低压触头材料,由于具备良好的耐电弧以及抗熔化焊能力,广泛适用于接触器,继电器以及低电压断路器中.采用金属元素Ni与Ge共掺杂的方式对SnO₂的导电性能进行改良.运用CASTEP软件对元素掺杂前后的SnO₂各项性能进行了仿真试验.结果表明：金属元素Ni与Ge单掺杂和共掺杂与本征SnO₂相比,其禁带宽度均会有不同程度的减小,其中Ni-Ge两种元素共掺杂时的禁带宽度值最小,这就表示电子可以更加容易的进行跃迁,其导电性也最好;由弹性常数分析可知,金属元素Ni-Ge共掺杂时材料的弹性最弱,韧性最强.     

The Elastic Continuum Limit of the Tight Binding Model

The authors consider the simplest quantum mechanics model of solids,the tight binding model,and prove that in the continuum limit,the energy of tight binding model converges to that of the continuum elasticity model obtained using Cauchy-Born rule.The technique in this paper is based mainly on spectral perturbation theory for large matrices.