1—3型压电复合材料的机械品质因素

采用切割—填充法制作1—3型压电复合材料，PZT—5A作为压电相，改性618环氧树脂作为聚合物相。研究了1—3型压电复合材料的机械品质因素Qm值与压电相的体积分数及形状参数的关系。压电相的体积分数及形状参数优选后的1—3型压电复合材料可获得较低的机械品质因素Qm值，其值可达10，谐振频率可达850kHz，频带宽度可达86kHz。     

非线性稳定性与奇异值的关系

研究了奇异值的大小与基流的非线性稳定性和不稳定性的关系。结果表明，它们两者之间存在很好的对应关系；奇异值的大小随着基流的稳定性（不稳定性）加强而变小（增大）。稳定情形下最大奇异值明显小于不稳定情形下的最大奇异值。     

酸催化二氧化硅溶胶的制备及稳定性研究

以正硅酸乙酯、水、乙醇为原料，硝酸为催化剂，制备了SiO2溶胶．研究了pH值、水量、乙醇量、反应温度、反应时间以及溶胶陈化温度等因素等对SiO2溶胶稳定性的影响，以便实现对二氧化硅溶胶稳定性的控制．实验结果表明，随着体系pH值的升高、乙醇量的增大，溶胶的凝胶时间延长，溶胶的稳定性也增强．随着体系水量的增加，溶胶的稳定性先减小后增大，在水酯摩尔比Rw=7．2时，溶胶的稳定性达到最小；随着反应温度的升高、反应时间的延长，溶胶的稳定性降低；采用较低的陈化温度有利于提高溶胶的稳定性．在溶胶粘度发生急剧变化之前溶胶是相对稳定的．     

O.05Ba(Cu1/2W1/2)O3-O.95PZT的性能研究

采用固相合成法制备0．05Ba(Cu1／2W1／2)03-0．95PZT三元体系压电陶瓷，研究了烧结温度对压电陶瓷压电性能的影响；通过XRD和SEM测试发现材料仍为钙钛矿结构，显微分析表明晶粒之间结合紧密，颗粒大小均匀；实验结果表明，压电陶瓷的压电系数d33为605pC／N，机电耦合系数Kp为0．37左右，机械品质因数Qm为60。     

桠柑精油提取工艺与稳定性研究

选用水蒸气蒸馏法提取桠柑皮中的香精油,并对桠柑皮精油的稳定性进行了初步研究．通过紫外分光光度法对精油于208nm处吸光值的测定,研究光照、温度变化及不同金属离子对桠柑精油稳定性的影响大小．研究结果显示,光照、温度均影响精油的稳定性,Na＋、Al抖在低浓度范围内对精油的稳定性影响不明显,Fe3＋对槛柑精油的稳定性影响较大．     

非线性稳定性与奇异直的关系

研究了奇异值的大小与基流的非线性稳定性和不稳定性的关系.结果表明,它们两者之间存在很好的对应关系;奇异值的大小随着基流的稳定性(不稳定性)加强而变小(增大).稳定情形下最大奇异值明显小于不稳定情形下的最大奇异值.     

降雨入渗下残积土坡失稳因素的敏感程度分析

以福州地区典型残积土为例,基于饱和-非饱和渗流理论,分析了降雨条件、土质物理力学参数、边坡几何形态等11种因素与边坡稳定性的关系,然后采用灰色关联法分析以上因素对于边坡稳定性的敏感程度与权重.结果表明:降雨条件下影响边坡稳定性的影响因素中,土体有效粘聚力和有效内摩擦角对边坡稳定性影响权重最大且相当;降雨强度是诱发残积土边坡失稳的重要因素,建议加强排水功能,减少降雨对边坡整体稳定性的影响;其余因素均对残积土边坡稳定性有较大影响,权重值大小相差不大.     

谷氨酸生产菌噬菌体鉴定和特性研究

对谷氨酸生产菌ＦＭ８２０－７、Ｔ６－１３分离到的６株噬菌体的形态学、生物学特性、ＤＮＡ和结构蛋白的分子量进行了比较。结果表明，各株噬菌体头部大小与尾部结构不同，除噬菌体１０２０外，其他噬菌体的宿主范围都较宽，ｐＨ值和温度稳定性稍有差别，各噬菌体的ＤＮＡ和蛋白分子量存在显著差异，还对噬菌体保藏方法进行了摸索。     

微乳液的制备及稳定性

采用十二烷基硫酸钠分别与十六醇、十六烷和十二烷组成的乳化体系、以丙烯酸丁酯分别与苯乙烯、甲基丙烯酸甲酯和丙烯腈为混合单体，制备了一系列微乳液，测定了乳液电导值，水相残留乳化剂浓度，单体液滴大小，离心稳定性，静置稳定性，讨论了乳化剂种类，用量和微乳化处理方式对乳液稳定性的影响。     

蛋白双酶（胰蛋白酶─木瓜蛋白酶）的固定化研究

以脱乙酰壳多糖为载体，戊二醛为交联剂，对胰蛋白酶和木瓜蛋白酶的固定化条件及固定化双酶的动力学性质进行研究．实验对比了交联剂的用量、交联的ｐＨ值、温度及载体与酶的比例等因素对固定化的影响．确定了固定化双酶的催化特性：最适ｐＨ７．５～８．１，最适温度是６０℃，Ｋｍ值是０．５２ｍｇ／ｍｌ，并对固定化双酶的热稳定性、固定化双酶的活性与固定化单酶的活性进行了比较．     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

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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