谈分级调节装配的线性尺寸链解算原理

分级调节装配的线性尺寸链解算原理是将调节环的公称尺寸视为变量，依据其它 各组成环的误差条件和装配技术要求，求解线性尺寸链，确定调节尺寸。具体解算过 程是．根据公差条件，求解一个极值尺寸链．得到一个极端条件下的调节尺寸并推算 出其它各级调节尺寸。由报算确定的另一极端条件的调节尺寸应满足相应条件的极值 尺寸链，并且封闭环公差应等于各组成环公差之和减去调节范围之差，由此来校核解 算结果。此外，调节环公差应取为封闭环公差之半为最佳．各级调节件的数量按统计 分析方法来确定。实例进一步归纳了解算过程     

装配尺寸链调整件数量的优化及确定

本文根据装配尺寸链和数理统计分析原理,推导出调整法装配时各级调整件的尺寸公差及其配套量,和实际生产中可采用的调整件尺寸的优化方法。     

AutoCAD环境下尺寸链的自动解算

介绍了尺寸链的数学描述方法．在此基础上，详细阐述了AutoCAD环境下标注尺寸的自动获取技术和尺寸链的自动解算原理．采用ObjectARX编制出相应的应用软件，在AutoCAD下运行即可实现尺寸链的自动解算．中给出了运行实例．     

尺寸链在完全互换将配中的应用

对尺寸链的基本概念及用极大极小法角尺寸链的计算公式进行了介绍,对解算将配尺寸链中遇到的正计算、反计算问题处理的方法、步骤进行了阐述,特别对等公差计算法进行了详细介绍,同时举例说明了解装配尺寸链的运算过程。     

准精度法解装配尺寸链

本文针对装配尺寸链反计算通常所采用方法的局限性,以公差与配合国家标准中有关标准公差的规定为依据,提出了新的解算方法.     

计算机辅助工艺尺寸链解算中工序公差确定方法研究

在讨论计算机辅助工艺尺寸链解算中工序公差的初拟及调整问题的基础上，提出了“高精度优先”的公差调整原则，并建立了通用的计算机算法。     

固定调节法装配计算程序

本文给出了采用固定调节法装配时解算尺寸链的BASIC语言通用程序,输入原始数据时,采用汉字提示,可在IBM—PC等微机上,完成全部计算。     

计算机辅助工艺过程设计中工艺尺寸链解算的研究

论述了工艺过程设计中工序尺寸公差的初拟及其调整问题,并对此建立了通用算法.针对目前计算机辅助工序尺寸计算中公差校核、工序尺寸公差调整等关键问题,提出了“高精度优先保证”公差调整原则,为解算工艺尺寸链提供了一个经济合理确定工序公差的新途径。     

矢量分析图解尺寸链

本文根据矢量误差的分布规律,按照尺寸链解算原理,应用矢量分析的矢量图,提出了解算尺寸链的一种新颖的方法。尤其对平面尺寸链的解算问题,具有简单、清晰,迅速求解的功效。此法,可以广泛应用于工程实际。     

平面尺寸链解算方法的探讨

本文对用全微分法解算平面尺寸链的极值法计算公式和概率法计算公式的推导过程,应用微分学的原理进行了较深入的探讨;并结合生产实际,应用实例说明了运用这种方法解算平面尺寸链的过程。     

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     

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