大模数硬齿面高精度滚剃刀的齿形制造

在进行大模数硬齿面高精度滚剃刀的研制中,将圆弧拟合的方法用于渐开线蜗杆的齿形制造,可以提高滚剃刀渐开线的齿形精度。本文采用圆弧拟合大模数滚剃刀渐开线蜗杆法截面齿形曲线,进行了渐开线蜗杆法截面齿形计算及圆弧拟合误差的分析计算,并采用计算机进行优化计算,将理论造型误差控制在0.7μm以下;通过对滚剃刀渐开线蜗杆的圆磨,使滚剃刀的齿形制造精度在AA级的水平上进一步提高,从而有效地保证了滚剃刀渐开线的齿形精度。该方法在使用中简单易行,为精度级渐开线蜗杆的制造提供了新方法。     

在三座标测量机上测量蜗轮齿形误差的方法

本文阐述了在三座标机上测量蜗轮齿形误差的方法。本文首先根据齿轮啮合理论建立蜗轮理论齿形方程式,编出计算程序算出蜗轮理论齿形,然后分析计算了测头干涉误差,最后编出了测量程序并在三座标机上进行了实测。     

圆弧齿轮蜗桿传动

本文着重研究圆弧齿形蜗杆傅动接触强度的计算方法。系先探讨圆弧齿条与齿轮的吻合情况,求出接触线长度,齿形曲率半径及其接触强度。然后,近似地用于计算圆弧齿形蜗杆傅动的接触强度。最后得出了圆弧齿形蜗杆傅动接触强度的计算公式。     

蜗杆凸轮机构的预紧干涉

本文叙述了蜗杆凸轮的结构型式和加工原理,并分析和证明了蜗杆凸轮机构产生预紧干涉的原因、干涉量的计算及消除干涉的方法。     

ZK 蜗杆与 ZI 蜗杆的齿形比较

论述了ＺＫ蜗杆传动和ＺＩ蜗杆传动的特点、使用情况及存在的问题,运用啮合原理和数学分析的方法,推导了ＺＫ蜗杆和ＺＩ蜗杆的齿面方程和轴向齿形方程,通过对ＺＫ蜗杆和ＺＩ蜗杆的轴向齿形进行比较,分析了其误差随蜗杆的头数和模数的变化规律及加工工艺对此误差的影响,为ＺＫ蜗杆和ＺＩ蜗杆的加工以及用ＺＫ蜗杆代替ＺＩ蜗杆提供了理论依据。     

蜗杆齿形分析

本文提出通过刀具与蜗杆的接触线作螺旋运动以获得蜗杆齿面的方法,对各种直纹面蜗杆与直纹面刀具的包络蜗杆的齿形分析给出一些统一计算公式,方法简单。本文还分析了这些蜗杆的齿形特性,可作为蜗杆与滚刀设计的参考。     

ZN_1蜗杆成形磨削砂轮修整研究

成形磨削是精密蜗杆磨削加工的发展趋势,而蜗杆磨削的齿形精度主要取决于成形砂轮廓形的精度。根据齿轮啮合原理建立ZN1蜗杆磨削加工的数学模型,用已知的蜗杆齿面形状求出了砂轮的廓形,通过MATLAB编程计算得到成形砂轮的轴向截形。利用三维建模技术验证了数学建模过程和计算结果的正确性,进而对砂轮修整安装参数进行了分析,得出了砂轮截形的变化规律。     

修磨轮双自由度修磨圆柱蜗杆齿形的异变分析

介绍一种精修磨圆柱蜗杆的新方法 ,即用高精度的渐开线齿轮形超硬修磨轮对圆柱蜗杆进行双自由度精修磨 .理论分析表明 ,修磨后的蜗杆齿面形状为 ZI蜗杆齿形 ,且在一定条件下 ,也可得到 ZA蜗杆齿形 .该方法也可用于精加工其它齿形的蜗杆 ,且操作简便 ,成本低 ,易于推广应用     

数字散斑干涉计量中的相位测量

针对散斑干涉计量的特点,结合相移相位测量技术,提出利用物体本身变化产生的相位变化来实现散斑干涉计量中相位的测量方法,从而得到不同时刻物体的相位变化.通过对计算机模拟漫射体产生离面倾斜的时变散斑图,计算其均方根误差值,进行了验证.     

基于坐标测量的准双曲面齿轮齿形精度控制

建立了表达准双面齿轮齿形精度的几何模型,计算分析了各加工误差独立存在时对准以面齿轮齿形精度影响的主次及相关性,利用齿面坐标测量值诊断齿轮加工参数误差,并确定误差补偿参数及其修正量。齿轮的补偿加工表明本方法可提高齿形加工精度。     

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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