锆与钍的分离及其测定

本文报告以邻碘苯甲酸作测定锆的试剂。在0.1—0.16N盐酸溶液中锆可定量沉淀,而且可与钍分离。最低测定量为0.8mg ZrO_2。拟订了用邻碘苯甲酸使锆与钍分离及其测定的方法。     

碳化锆/锆涂层炭纤维的制备及其拉伸性能研究

在一定反应温度范围内以熔盐为介质通过炭纤维与金属锆反应制备出碳化锆/锆涂层炭纤维,并在反应温度为800℃时,研究反应时间对碳化锆/锆涂层炭纤维表面相组成、形貌及其拉伸性能的影响。结果表明,800℃可制备均匀致密的碳化锆/锆涂层;且随着反应时间的延长,碳化锆/锆涂层厚度略有增加;涂层后炭纤维的拉伸强度和拉伸模量比原炭纤维的相应值略有减小。     

氧族元素取代的烯基锆化合物的合成及应用研究进展

介绍了近几年氧族元素取代的炔烃、烯烃与有机锆试剂作用生成官能团化烯基锆化合物的反应及其在有机合成中的应用研究进展.     

镁锆铬质无碳钢包渣线耐火浇注料

实验以轻烧氧化镁和锆英石为原料,采用湿法共磨工艺,合成了镁锆质熟料.并以此为主要原料研制了镁锆铬质浇注料.实验证明,镁锆铬质浇注料的抗渣侵蚀能力、抗渣渗透能力较高.     

从铌钽矿无磁尾矿中回收锆钍的研究综述(二)

本文综合报道了国内外从锆矿中制备氧氯化锆的各种工业方法以及生产与研究现状。     

镁锆铬质无碳钢包渣线耐火浇注料

实验以轻烧氧化镁和锆英石为原料，采用湿法共磨工艺，合成了镁锆质熟料。井以此为主要原料研制了镁锆铬质浇注料。实验证明，镁锆铬质浇注料的抗渣侵蚀能力、抗渣渗透能力较高。     

某些取代苯甲酰氧基二茂锆化合物的研究

本文报道了两个系列共24个取代苯甲酰氧基二茂锆化合物的合成及其波谱性质,通过波谱解析,确定了这些化合物的结构,并发现邻硝基苯甲酰氧基氯化二茂锆与其它同类化合物在结构上有所不同。     

锆铪萃取工艺中钍的分析

本文就锆及硫酸根对偶氮胂Ⅲ比色测定钍的干扰与消除作了较为详细的研究,并为锆铪萃取工艺废水及类似体系中钍的分析,提供了一条合理可靠的途径。     

碳化锆镀层的化学气相沉积

碳化锆是一种重要的高熔点、高强度和耐腐蚀的高温结构材料。为了进一步发展和开发利用高温气冷堆 ,用碳化锆镀层替代碳化硅镀层制备新型的包覆燃料颗粒。采用化学气相沉积的方法 ,选用四氯化锆、丙烯、氢和氩的反应体系 ,在直径为 5 5 m m的流化床沉积炉中制备碳化锆镀层。为控制四氯化锆粉末的流量研制了专用的送粉装置。研究表明碳化锆镀层的密度随沉积温度而变化 ,反应气体中碳锆的原子数比值和氢氩流量比值影响碳化锆镀层性能和结构。在沉积温度 16 0 0℃左右 ,反应气体中碳锆的原子数比值小于0 .5和氢氩流量比值大于 1.0时 ,可以制备出高密度的碳化锆镀层     

镁锆质耐火材料的性能研究

以电熔镁砂和锆英石为原料,研究锆英石质量分数和烧成温度对镁锆质试样物理性能的影响,利用X射线衍射、扫描电镜及能谱分析等手段对试样的物相组成和显微结构进行分析.结果表明,当锆英石质量分数为20%、烧成温度为1 650 ℃时,镁锆质试样具有最佳的物理性能;当锆英石质量分数超过20%,试样的物理性能和热震稳定性开始下降.试样的主要物相由t-ZrO2、方镁石和镁橄榄石组成,t-ZrO2晶粒与MgO晶粒交错分布,形成二相结构.     

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