锰酸镧结晶行为的研究

本文采用淀粉类衍生物作有机多功能酸络合剂的溶液合成法制备纳米钙钛矿Ｌａ０．８Ｓｒ０．２ＭｎＯ３＋ｘ．通过透射电镜（ＴＥＭ）和Ｘ射线衍射仪（ＸＲＤ）等分析手段，研究了在１００℃下蒸发、炭化及经４００～１３００℃不同温度下煅烧３ｈ后的显微结构和相结构变化．结果表明：钙钛矿结构Ｌａ０．８Ｓｒ０．２ＭｎＯ３＋ｘ相的形成温度为５００℃，其形成温度低的原因可能是炭化后金属离子与其它离子或基团结合力较弱因而活性高．７００℃是比较理想的煅烧温度，由此制得粉体结晶完整，且晶粒细小．晶粒尺寸２０ｎｍ左右，颗粒尺寸为１５～６０ｎｍ．     

纳米Mn2O3的制备及其分形凝聚

采用化学液相均相沉淀法制备出纳米Ｍｎ２Ｏ３材料，并用Ｘ射线衍射（ＸＲＤ）、透射电镜（ＴＥＭ）和高分辨电镜（ＨＲＥＭ）对其微结构特点进行了研究．首次在Ｍｎ２Ｏ３材料中观察到了分形凝聚现象．     

纳米氧化镁的合成

以ＭｇＣｌ２·６Ｈ２Ｏ和ＣＯ（ＮＨ２）２为原料，采用均匀沉淀法合成了纳米ＭｇＯ．讨论了反应温度、煅烧温度和时间对产物的影响，通过ＸＲＤ和ＴＥＭ对纳米ＭｇＯ进行了表征．     

溶胶-凝胶法制备超细Y_2O_3: Eu~(3+)

以金属醇盐为原料,采用溶胶－凝胶法制备出均匀的、体心立方结构的Ｙ２Ｏ３Ｅｕ３＋超细粉末．借助ＴＧ－ＤＴＡ、ＩＲ、ＸＲＤ和ＳＥＭ等分析手段,研究了凝胶的转变过程和粉末的结构,观察了粉末的形貌和粒径．结果表明：在４２３℃煅烧已有Ｙ２Ｏ３Ｅｕ３＋相生成,经８５０℃煅烧即得单－Ｙ２Ｏ３Ｅｕ３＋相超微粉,平均晶粒尺寸为５３ｎｍ;煅烧温度进一步升高,Ｙ２Ｏ３Ｅｕ３＋晶粒长大     

湿化学法合成铌镁酸铅陶瓷微观结构

用湿化学法合成铌镁酸铅陶瓷，用Ｘ射线（ＸＲＤ），扫描电镜（ＳＥＭ）和透射电镜（ＴＥＭ）技术，研究陶瓷的微观结构，结果表明：湿化学法可合成纯钙钛矿相的铌镁酸铅陶瓷；陶瓷在８５０～９２０℃烧结，晶粒大小为１５０～２００ｎｍ，细小焦绿石相出现并分布在晶界上；过量ＰｂＯ相的形成有利于陶瓷的烧结。     

Mo—Ni／γ—Al2O3甲烷化催化剂MoNi4合金的生成及其作用

通过变化浸渍液的ｐＨ 值、焙烧温度及还原温度制备了几种Ｍｏ－Ｎｉ／γ－Ａｌ２Ｏ３ 甲烷化催化剂,用Ｘ 射线粉末衍射（ＸＲＤ）、透射电子显微镜（ＴＥＭ）法对催化剂的结构和性能进行了考察,用脉冲气相色谱法测定了催化剂的ＣＯ 甲烷化活性及抗硫性．结果表明,Ｍｏ－Ｎｉ催化剂经还原处理后有ＭｏＮｉ４ 合金生成,ＭｏＮｉ４ 合金是主要的抗硫活性相,提高了甲烷化反应的抗硫性     

制备方法对SnO2超微粉气敏性的影响

本文采用透射电镜（ＴＥＭ），光电子能谱（ＸＰＳ）等手段，对溶液沉淀法和低温等离子体法制备的ＳｎＯ２超微粉的微结构进行了分析比较．通过计算得到了它们的表面氧吸附活化能值，说明不同的制备方法对粉料的活性有很大影响，从而影响用这种粉料制备的气敏元件的气敏特性．     

低温烧结PZT压电陶瓷的研究

对ＰＺＴ压电陶瓷的低温烧结进行了研究。实验发现，在ＰＺＴ陶瓷中添加少量低 熔玻璃（ｘＢ２Ｏ３－чＢｉ２Ｏ３－ｚＣｄＯ）可使烧结温度从１２５０℃降低至９６０℃。其性能参数： Ｋｐ≥０．５２～０．５６，Ｑｍ≥１０００，ε３３Ｔ／ε０＝８００～１２００， ｔｇδ≤５×１０－３．借助于扫描电镜 （ＳＥＭ）、电子探针微区分析（ＥＰＭＡ）、Ｘ光光电子能谱分析（ＸＰＳ）和体积烧缩速率的 测量，对陶瓷显微结构、烧结机理和添加剂的作用进行了讨论，所研制的低温烧结瓷料 巳用于制备独石压电陶瓷变压器，其空载交流升压比可高达 ９ ０００以上。     

晶体助长剂对α—Fe2O3晶形影响的初步研究

研究了晶体助长剂（ＨＥＤＰ、酒石酸、柠檬酸、ＮａＨ２ＰＯ４）及其浓度对１００℃陈化法制备的αＦｅ２Ｏ３晶形的影响，并采用ＴＥＭ、ＸＲＤ、ＩＲ光谱对产物进行了表征．     

最新MOTOROLA V998+手机电源电路介绍及开机过程

ＭＯＴＯＲＯＬＡＶ９９８+手机的电源及音频处理模块由一块ＧＣＡＰ（Ｕ９００）完成,ＥＰＲＯＭＴ和ＥＥＰＲＯＭ由一块Ｕ７０１完成,ＳＹＮ-ＭＤＥＭ（频率合成及调制节调）由一块ＭＡＧＩＣ（Ｕ９１３）完成。逻辑控制ＣＰＵ是ＷＨＩＴＥＣＡＰ（Ｕ７００）。１介绍各个电压在逻辑控制下的先后产生过程１．１Ｂ+电压当ＥＸＴ-Ｂ+供电时,Ｕ９００的Ｆ１０脚输出高电平,Ｑ９４２的Ｓ-Ｄ截止,Ｂ+由ＥＸＴ—Ｂ+产生。当ＢＡＴＴ+供电时,Ｆ１０脚输出低电平,Ｑ９４２的Ｓ-Ｄ导通,Ｂ+由ＢＡＴＴ+产生。ＣＲ９４０为隔离二极管。１．２Ｖ-Ｂ０…     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has