微量元素对ZrO_2基陶瓷显微结构的影响

本文在常压固态烧结条件下,通过掺加3mol%Y_2O_3和微量氧化物作为晶粒稳定剂和晶粒生长阻碍剂制备出超细化,高密度的四方ZrO_2多晶陶瓷。通过密度测定、X射线衍射、扫描电镜和透射电镜等测试方法分析了微量氧化物CuO,Fe_2O_3和SiO_2对ZrO_2基陶瓷显微结构的影响。     

非晶Li^＋离子导体晶化初期导电性能的研究

研究了非晶态Ｌｉ２Ｏ－ＬｉＣｌ－Ｐ２Ｏ５－（Ａｌ２Ｏ３）和Ｌｉ２Ｏ－Ｐ２Ｏ５－Ｖ２Ｏ５系统晶化前期的Ｌｉ＾＋离子导电特性。两系统的Ｌｎ（σＴ）￣１／Ｔ曲线上都有两个转折点：当Ｔ〈Ｔ１时，Ｌｎ（σＴ）￣１／Ｔ满足Ａｒｒｈｅｎｉｕｓ的直线关系；而在Ｔ１￣Ｔ２温度范围内电导率呈反常增加；当Ｔ〉Ｔ２时电导率又开始下降或趋于平稳。用差热分析、扫描电镜、Ｘ镜线衍射技术对晶化前期（Ｔ１￣Ｔ２）电导率反常增加现象     

教师信息化教学能力研究现状与分析

随着社会信息化程度的提高,教育与信息化的融合成为教育工作的重点,教师作为教育之本,更要提高信息化教学能力,其对促进教师队伍的专业发展、推进教育信息化乃至教育改革具有重要意义。本文以我国知网学术期刊数据库中关于教师信息化教学能力的文献为分析样本,总结出我国关于教师信息化教学能力的主要研究内容,具体包括其内涵、结构、影响因素、发展阶段、提升策略五方面,总结目前国内教师信息化教学能力研究取得的进展以及尚存的不足。     

PMMN四元系压电陶瓷结构与性能的研究

用ＰｂＯ、ＺｒＯ＿２、ＴｉＯ＿２等原料经固相反应烧结制备了ＰＺＴ基四元系压电陶瓷。ＸＲＤ、ＳＥＭ及密度测试表明，材料主晶相为四方晶系的Ｐ４ｍｍ群，烧结致密度较好。极化后的性能测试表明，材料具有高介电系数（ε＿ｒ＝２０１５），压电系数（ｄ＿（３３）＝５７８×１０￣（－１２）Ｃ／Ｎ），机电耦合系数（Ｋ＿（３３）＝０．８１）和良好的机械品质因数（Ｑ＿ｍ＝５４３．８），是压电高压装置的理想材料。     

STUDY ON STRUCTURE AND PROPERTIES OF PMMN PIEZOELECTRIC CERAMICS

Piezoelectric ceramics based on PZT ceram-ics were prepared in solid state reaction with mixture ofPbO,TiO_2 and ZrO_2,etc.XRD and SEM were used to con-firm that the main phase in the material is tetragonal P4mmsymmetry.Samples sintered are of high density.Measurementon polarized products indicate that dielectric constant,piezo-electric constant,electromechanic coupling factor and mechan-ical quality factor are ε_r=2015,d33=578.06×10~(-12)C/N,K_(33)=0.81 and Q_m=543.8,.respectively.     

COLOUR-CHANGING MECHANISM IN P_2O_5-Nb_2O_5-Li_2O NONCRYSTALLINE SYSTEM

Raman, IR spectra, RDF and visible spectrum were used to study the glass structure and the valence states of niobium ions in P_2O_5-Nb_2O_5-Li_2O noncrystalling system. The colour-changing mechanism was studied. For 10Nb_2O_5xP_2O_5(90-x)Li_2O (x=40,45,50,55) system glasses, it was known that the glass colout changing from light gold-yellow to blue with increasing is aroused by the Nb~(3 ) ion increasing, not by the change of niobium ion coordination.     

STUDY ON THE DEPENDENCE OF SUPERCONDUCTIVITY ON MICROSTRUCTURES FOR Ba-Y-Cu OXIDE MATERIALS

Two kinds of ceramic superconductors of Ba-Y-Cu-O system in which the ratios of Ba:Y:Cu are equal to2:1:3 and 2:3:3,respectively,and two kinds ofceramic materials without superconductivity with thesame compositions were made.Their crystal structureswere analyzed by X-ray diffractions (XRD).Theirmicro-morphology was studied by means of TEM,and theelement distributions in all the samples were studiedby energy diffraction analyzer of X-ray (EDAX).Theresults show that the superconductivity of thematerials in this system have much to do with theirmicrostructures beside the crystal species and therelative contains of all crystals in them.     

La_2O_3-Li_2O-B_2O_3三元系统玻璃的分子振动光谱研究

本文用群论方法分析了xLa_2O_3 20Li_2O·(80-x)B_2O_3三元系统玻璃,进行了拉曼与红外光谱测试,着重研究了La_2O_3对本系统结构的影响,发现了La_2O_3的作用与Li_2O相似,随着x增加,玻璃结构的演变过程为: 四硼酸盐基团—→二硼酸盐基团—→偏硼酸盐基团。在高La_2O_3情况下还产生焦硼酸盐和正硼酸盐基团,为探索锂快离子导体玻璃态新材料提供一定的基本认识。     

Ba-Y-Cu氧陶瓷超导材料

引言高转变温度的超导材料的研究,近期取得了惊人的突破。Ba-Y-Cu-O超导材料的电性能,由零电阻效应和Meissner效应所证实,最高临界温度可达52K。文献报导了中国科学院物理所研制的Sr-La Cu-O和Ba-La Cu-O系统高转变温度超导材料,在Y