AutoCAD系统机械图尺寸及公差自动标注功能的开发

本文论述了以微机辅助绘图软件ＡｕｔｏＣＡＤ为图形支撑软件实现机械图尺寸公差自动标注和尺寸标注的程序设计方法。用这种方法设计的程序面向用户，标注参数易于控制，使尺寸公差自动标注成为可能。     

AutoCAD绘图软件常用尺寸标注的优化

基于我国机械制图标准［１］,分析了美国 Ａｕｔｏｄｅｓｋ公司的ＡｕｔｏＣＡＤ通用绘图软件在尺寸标注方面的欠缺,并在 ＡｕｔｏＣＡＤ平台上对常用尺寸标注作了优化,以达到尺寸标注的国标化更具实用性．     

箱体类零件各视图尺寸的分配

论述的内容为“箱体类零件工作图尺寸智能化标注”的一部分。简要介绍了尺寸标注的内容，零件各视图尺寸分配的原则，并着重介绍了各视图尺寸分配的具体方法     

交互式绘制零件图软件

本文所述的交互式绘制零件图软件不用编写程序可描绘任意图形，标注尺寸及公差，书写字符及画表面粗糙度符号，并可起到数字化仪的鼠标器作用．     

定制符合《机械制图》国家标准的图纸标注

阐述了利用AUTOCAD绘制机械工程图时，如何使图纸上的标洼符合《机械制图》国家标准，介绍了文字标注、尺寸标注和尺寸公差标注的实现方法．     

计算机尺寸标注算法的研究

本文归纳了机械制图中各种尺寸标注形式为直线型、角度型、直径型和半径型四种．以形式最为繁杂的直线型尺寸标注为例，研究提出计算机通用尺才标注算法，较好地解决了计算机参数化绘图技术中的瓶颈──尺寸标注问题．并在＂链条少齿差行星减速机的ＣＡＤ＂和＂主轴单元ＣＡＤ＂等攻关项目中验证应用成功．     

AutoCAD标注机械图样尺寸公差的实现方法

虽然AutoCAD软件在机械图样绘图方面已比较成熟,但尺寸及公差标注方法繁琐,易破坏尺寸块的整体性,特别是在尺寸公差的标注上更显不足。在对AutoCAD尺寸标注样式分析的基础上,用AutoCAD VBA和AutoCAD Actiomation结合提取标注实体数据,即基本尺寸,然后添加文本字符串的方法解决了尺寸公差的标注问题。     

FSAE赛车悬架安装座三维定位尺寸算法与CAE分析

该文旨在探索一种专门汽车悬架安装座定位尺寸的确定方法．首先根据机械制造工艺和几何原理,建立定位尺寸计算的工程模型;然后利用AutoCAD软件建立悬架安装座处三维结构几何模型,模拟各种安装位置,标注定位尺寸,最后对工程模型计算结果和软件标注结果进行比较和评价．研究表明：随着旋转角度增加,定位点A与球关节中心O点高度差也增加,而定位点A与球关节中心O点Y向差则减少．文申提出的工程模型可以作为汽车暴粲安装时的理论指导．     

树结构参数化设计的搜索策略与算法

从机械工程图尺寸标注的特点出发，提出了一套新的参数化设计方法，并阐述了尺寸链中各级尺寸的搜索方法、尺寸驱动算法、中心线对称标注尺寸的搜索及尺寸驱动算法．     

基于标注字符的尺寸标注自动识别

本文通过对工程图中的尺寸标注进行详尽的结构分析,提出了工程图尺寸标注拓扑结构分类方法和基于标注字符的尺寸标注自动识别方法,并得到了成功的应用．     

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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