双半环的粗糙性质

在双半环上引入了粗糙集并研究了粗糙子双半环,利用双半环的非空子集上关于同余关系的上、下近似,给出了双半环的粗糙子双半环的定义,证明了双半环的子双半环一定是双半环的子双半环,理想一定是粗糙理想。     

半群的完备模糊双理想

在半群的广义模糊双理想和模糊双理想概念的基础之上,给出了半群的完备模糊双理想、双-半群、模糊双-半群的概念,并且从模糊点的角度研究其相应的性质.进一步地,得出了广义模糊双理想成为模糊双理想,一个半群成为模糊双-半群的等价条件以及双-半群和模糊双-半群之间的相互关系.     

双半环簇的拟强半格

研究了乘法左正规双半环的结构,且证明了这种双半环是乘法左零双半环的拟强半格,并得出这种双半环和含幺双半环的直积是Lz-双半环的拟强半格.     

有机磷化合物的合成研究

以金属锂和三苯基膦为起始原料,合成了8种有机膦化合物,即双二苯基膦甲烷dppm,双二苯基膦乙烷dppe,双二苯基膦丙烷dppp,双二苯基膦丁烷dppb,双二苯基膦戊烷dppr,双二苯基膦乙烯dppey,二苯基膦吡啶dppy,双二苯基膦乙烷之氧化物dtpeo,讨论了反应时间、温度、溶剂等对产率的影响,总结出一套合成含膦有机化合物的有效方法。     

半群的带限度（λ，μ）-双极值模糊双理想

将双极值模糊集应用于半群,引入了半群的带限度(λ,μ)-双极值模糊双理想和(λ,μ)-双极值模糊广义双理想的概念,讨论了半群的(λ,μ)-双极值模糊(广义)双理想的基本性质.分别给出了半群的(λ,μ)-双极值模糊双理想与模糊双理想及半群的双理想的关系.证明了半群的(λ,μ)-双极值模糊(广义)双理想的交和直积仍是半群的(λ,μ)-双极值模糊(广义)双理想.     

矩形Clifford双半环的性质与结构

利用双半环的分配格和带双半环,将左双环和左Clifford双半环进行推广,得到了矩形双环和矩形Clifford双半环的概念。给出了矩形双环和矩形Clifford双半环的刻画,得到了矩形Clifford双半环在一定条件下的织积分解以及矩形Clifford双半环是矩形双环的强分配格的充分必要条件。     

天津市“双创”金融现状及对策研究

2018年,天津市"双创"金融指数综合排名居全国第11位,整体"双创"金融发展略有下降;在"双创"金融机构和"双创"金融服务方面具有优势,尤其是金融机构数量位于全国第5位;在"双创"金融绩效、"双创"金融政策和"双创"金融生态方面较其他城市缺少竞争力,尤其是"双创"金融政策位居全国第26位。文章基于中国31个主要中心城市的"双创"金融指数比较分析,提出天津市"双创"金融未来发展的对策建议。     

双半环簇的强右正规带

研究了正规的型A-幂等双半环的结构,且证明了这种双半环是左零幂等双半环的强右正规带,并得出了这种双半环和含幺幂等双半环的直积是型A-左幂等双半环的强右正规带的结论.     

左Clifford双半环的性质与结构

定义了双半环的分配格和带双半环。利用这两个定义以及左Clifford半群的性质,给出了左双环和左Clifford双半环的定义,并得到了双半环是左双环的充分必要条件和双半环是左Clifford双半环的充分必要条件。     

重型汽车转向双摇臂机构的优化设计

转向双摇臂机构的运动协调性直接影响双前桥重型汽车的行驶性能,因此对其转向双摇臂机构的优化设计具有重要意义。文章介绍了重型汽车转向双摇臂机构的转向原理,用空间几何方法建立了双摇臂机构优化设计的数学模型,并用MATLAB软件优化工具箱中的优化计算函数来编制程序,对双摇臂机构参数进行了优化,使转向双摇臂机构的性能得到显著提高。     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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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