掺杂浓度和温度对δ掺杂的Al_xGa_(1-x)As/GaAs双量子阱系统电子态结构和子带间光学吸收系数的影响

在有效质量近似下,通过自洽求解薛定谔方程和泊松方程,计算了在温度不为零时δ掺杂的AlxGa1-x As/Ga As双量子阱系统的电子态结构.研究了温度和掺杂浓度对双量子阱系统子带能级、费米能量、及子带间线性光学吸收系数的影响.研究发现,系统的本征能量随温度升高或随掺杂浓度的增大而增加;费米能量随温度升高而减小,随掺杂浓度的增大而增加;子带间总的吸收系数随温度的升高而减小,随掺杂浓度的增大而增加.除子带间跃迁3-6,4-5随温度升高线性光学吸收系数增加外,其他各主要子带间跃迁随温度升高线性光学吸收系数而减小;各子带间线性光学吸收系数随掺杂浓度的增大而增加.     

考虑到纵向掺杂分布影响的SOI功率器件完全耐压模型

首先将任意纵向掺杂的漂移区等效为均匀掺杂的漂移区,然后基于二维泊松方程获得了SOI功率器件在全耗尽和不全耗尽情况下表面电场和击穿电压的完整解析表达式.借助此模型对漂移区纵向均匀掺杂、高斯掺杂、线性掺杂和二阶掺杂SOI二极管的表面场势分布和击穿电压进行了研究,解析结果和仿真结果吻合较好,验证了模型的准确性.最后在满足最优表面电场和完全耗尽条件下,得到器件优化的广义RESURF判据.     

Al_2O_3掺杂ZnO线性电阻的性能及其显微组织

通过高能球磨法,分别在1 250,1 300,1 350℃下制备了掺杂量为3.5%,4.0%,4.5%,5.0%的Al2O3掺ZnO线性电阻,通过扫描电镜和X射线衍射对其显微组织和相成分进行了分析,探讨了不同Al2O3掺杂量和不同烧结温度对ZnO线性电阻的线性性能和介电性能的影响.结果表明:掺杂A12O3的ZnO线性电阻主晶相为ZnO,并伴随有少量锌尖晶石相生成.在烧结温度为1 350℃,Al2O3掺杂摩尔分数为3.5%时,线性电阻性能最优,其非线性系数为1.00.另外,随A12O3掺杂量增大,ZnO线性电阻的介电常数变化不大,而烧结温度对陶瓷的介电常数有较为明显的影响.     

新型复合稀土掺杂ZnO-Bi2O3基压敏陶瓷

采用固相法制备新型复合稀土Sc2O3和Y2O3掺杂ZnO-Bi2O3基压敏陶瓷,并对其显微组织和电性能进行了分析.结果表明,复合稀土掺杂可提高压敏陶瓷的综合性能,并明显优于单一稀土掺杂,复合稀土掺杂对压敏陶瓷电性能的影响规律仍遵循单一稀土掺杂对压敏陶瓷电性能的影响规律.新型复合稀土Sc2O3和Y2O3掺杂ZnO-Bi2O3基压敏陶瓷,在相同的Sc2O3掺杂比例下,随Y2O3掺杂量的增加,电位梯度呈增加的趋势;在相同的Y2O3掺杂比例下,随Sc2O3掺杂量的增加,非线性系数呈增加的趋势.当掺杂Sc2O3的摩尔分数为0.12%、Y2O3的摩尔分数为0.20%时,复合稀土掺杂ZnO-Bi2O3基压敏陶瓷的综合电性能最为理想,电位梯度为410V·mm-1非线性系数为38.0,漏电流为0.58 μA.     

Sm掺杂Ti/SnO2-Sb电极电催化氧化性能

采用涂层热解法制备Sm掺杂Ti/SnO2-Sb电极.以C6H5NO3(对硝基苯酚)为目标有机物,考察不同热处理温度、不同Sm掺杂量下制备的电极的电催化性能,采用LSV(线性扫描曲线)、降解曲线和破损的分析方法研究电极的电催化氧化性能和使用寿命.结果表明:最佳热处理温度为550℃,xSn∶xSb∶xSm=100∶10∶1电极的综合性能最好.在降解有机物试验中,不掺杂Sm的电极降解率为74.4%,掺杂率为1%的电极降解率为85.6%,掺杂率为2%的电极的降解效率仅为74.2%.因此,适量的稀土Sm掺杂有利于提高电极的电催化性能.     

氧化镧掺杂氧化锌在天然胶乳预硫化工艺中的应用

采用氧化镧掺杂氧化锌代替普通氧化锌对天然胶乳进行预硫化,通过测定天然胶乳硫化程度以及硫化胶膜交联密度、溶胀指数、力学性能等,探讨氧化镧掺杂氧化锌对天然胶乳预硫化工艺和硫化胶膜性能的影响。结果表明,使用相同份数掺杂氧化锌取代普通氧化锌,能明显加快天然胶乳硫化反应速率,提高硫化胶膜的溶胀指数、交联密度和拉伸强度。在硫黄和促进剂用量不变的前提下,采用0.2份掺杂氧化锌代替0.5份普通氧化锌,硫化胶膜溶胀指数和交联密度略有下降,但力学性能基本保持不变。     

次线性期望空间下广义ND序列的重对数律

运用Markov不等式和Kolmogorov指数不等式,在一般矩条件下,得到了次线性期望空间下同分布广义ND序列的重对数律,从而推广了次线性期望空间下的重对数律.     

Half-Heusler合金CoMn1-xNbxSb的

采用密度泛函理论(DFT)在广义梯度近似(GGA)下的平面波超软赝势方法,研究了Half-Heusler合金CoMn1-xNbx Sb(x=0,0.25,0.5,0.75,1)的电子结构和磁性.通过几何优化和能量计算,得到了合金的晶格常数、电子和自旋分布以及自旋磁矩的大小.通过分析得到当掺杂浓度x<0.75时,CoMn1-xNbxSb合金具有半金属铁磁性质,并且自旋磁矩随着Nb掺杂的增加而线性地减小,和Slater-Pauling曲线符合得很好.当掺杂浓度x=1时,体系从铁磁半金属转化成泡利金属.     

一般多元线性问题的指数收敛(s,t)-弱易处理性

在最坏框架下研究一般多元线性问题的逼近.考虑利用连续线性泛函信息类所构造的算法.对定义于Hilbert空间上的一般多元线性问题,给出了其为指数收敛(s,t)-弱易处理相匹配的充要条件,结果是基于相应的特征值序列.     

多时滞不确定系统的鲁棒指数镇定

基于新型稳定性分析技术及线性矩阵不等式方法,研究了含有参数不确定性的线性多时滞系统的鲁棒指数镇定问题.首先,对不含参数的不确定性时滞系统设计无记忆状态反馈控制器,给出了在该控制器作用下,闭环系统指数稳定的线性矩阵不等式形式的充分条件;然后,将其推广到含有范数有界参数不确定性的时滞及多时滞线性不确定系统,得到了保证系统鲁棒指数稳定的充分条件,并提供了指数衰减度及衰减因子的估计方法.所给出的判据避免了现有文献中对时变时滞导数小于1的要求,比已有的结果具有更少的保守性,数值例子验证了本方法的有效性.     

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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