平面凸轮机构中的相似统一性研究

阐述了平面凸轮机构中的相似性现象，用平面凸轮机构中的三个圆－－特征圆基圆及大圆，给出了直动型和摆动型平面凸轮运动转角相似的三种统一度量表示方法；用解析几何方法推导了这两种凸轮轮廓曲线任一点具有相似结构的压力角计算公式，并赋予通用公式表示。     

平面凸轮机构中的相似统一性研究

阐述了平面凸轮机构中的相似性现象．用平面凸轮机构中的三个圆──特征圆、基因及大圆，给出了直动型和摆动型平面凸轮运动转角相似的三种统一度量表示方法；用解析几何方法推导了这两种凸轮轮廓曲线任一点具有相似结构的压力角计算公式，并赋予通用公式表示．还探讨了这两种结构形式貌似不同的凸轮机构的演化机理．揭示凸轮机构中的相似现象，有利于寻找新的凸轮机构分析与设计方法．     

共轭曲面理论在平面凸轮机构中的应用

本文以共轭曲面理论为基础,用运动学法建立了凸轮及其对偶件间的接触方程,借鉴齿轮啮合原理的研究成果,给出了一套用于平面凸轮机构和反凸轮机构的公式,可以方便地计算凸轮廓线、曲率半径、压力角、干涉界点、接触界点、瞬心线和滑动率等。本文提出的模型适用于各类平面凸轮机构和反凸轮机构,并形成一个比常用的方法更为完整的理论体系。     

基于Pro/E参数化建模技术的凸轮轮廓线精确设计

凸轮机构实现推杆预期的运动规律要依赖于凸轮轮廓曲线,凸轮机构设计的主要任务是凸轮轮廓曲线的精确设计．利用Pro／E软件方便快捷地设计平面凸轮和三维凸轮轮廓曲线．并通过运动仿真的分析结果说明设计的凸轮机构能够满足预期的要求．     

机床设计中圆柱凸轮机构设计的探讨

介绍了-18级卧式车床的机构原理,推导出由直线过渡到直线和由非直线过渡到直线的过渡曲线方程，即圆柱凸轮曲线方程，并讨论了凸轮机构直径的确定问题。     

推导凸轮机构压力角表达式的通用有效新方法

以虚位移原理为理论基础和出发点，提出了一种简单通用、行之有效的推导凸轮机构压力角表达式的新方法。它对于平面与空间凸轮机构同样适用。     

新型行星分度凸轮廓线设计及仿真

针对现有分度凸轮机构存在的难以用紧凑结构实现大分度数的问题，根据少齿差行星齿轮传动中的三环传动原理，提出了一种行星分度凸轮机构Ⅲ型结构．根据共轭齿廓形成原理推导了凸轮理论廓线和实际廓线方程．利用Matlab软件，进行了机构的运动仿真．该机构结构简单，没有输出机构，从而减少了输出环节，可提高分度精度．凸轮的理论廓线有自相交现象．凸轮的实际廓线是以理论廓线为中心，以针齿半径为半径形成的包络线，即内、外等距曲线拼接而成的．     

共轭凸轮轮廓曲线曲率半径的计算

本文应用复极矢量法对共轭凸轮机构进行分析研究,推导出在一般假设条件下,该机构两种主要接融形式的凸轮轮廓曲线曲率半径的计算公式,能广泛应用;与传统的计算方法相比,更便于CAD中计算机程序的编制.     

基于MATLAB的可视化凸轮曲线设计程序

简要阐述了现代制造业中凸轮设计的重要作用。介绍了通用凸轮曲线的设计原理并进行了推导。在此基础上开发了一系列通用凸轮曲线的MATLAB可视化设计程序，并举例验证了其效果。最后在结论中提出了若干改进的方向。     

按许用压力角(α)确定直动从动件盘形凸轮机构凸轮最小基圆半径

本文推导和证明了按许用压力角[a]计算直动从动件盘形凸轮机构凸轮最小基圆半径和偏距 e 的公式,指出了使用这些公式的充分条件,并证明了作常用运动规律的直动从动件盘形凸轮机构可以用这些公式计算凸轮的最小基圆半径和偏距 e,使这类机构的设计更为方便、准确和可靠。     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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