五轴数控技术在多维曲面零件加工的应用

多维曲面零件是多轴零件切削加工的一个难点,多维曲面加工容易出现刀具干涉等问题。本文以人的头像加工为例,详细地分析了多维曲面零件的加工工艺,给出了人的头像的多轴数控加工程序,并通过实际加工,验证了此刀路的正确性。     

自由曲面的加工与CAM参数

用ＣＡＤ／ＣＡＭ 系统在３ 轴立式数控铣床上加工自由曲面, 需要确定ＣＡＭ 参数－ 本文根据ＣＡＭ 参数与零件几何要求之间的联系, 确定了一种选则ＣＡＭ 参数的方法－     

五轴数控技术在多维曲面零件加工的应用

多维曲面零件是多轴零件切削加工的一个难点,多维曲面加工容易出现刀具干涉等问题。本文以人的头像加工为例,详细地分析了多维曲面零件的加工工艺,给出了人的头像的多轴数控加工程序,并通过实际加工,验证了此刀路的正确性。     

自由曲面的加工与CAM参数

用ＣＡＤ／ＣＡＭ系统在３轴立式数控铣床上加工自由曲面,需要确定ＣＡＭ参数,本文根据ＣＡＭ参数与零件几何要求之间的联系,确定了一种选则ＣＡＭ参数的方法。     

基于UGNX的整体叶轮逆向建模与五轴编程

复杂的叶片曲面导致整体叶轮的测量、逆向再设计及数控编程非常困难.通过测量整体叶轮样品关键特征点,基于UGNX对点云进行逆向并用曲面模块生成了三维模型,应用UG/CAM中叶轮加工专用模块,实现了叶轮五轴数控编程.在利用IS&V消除干涉、过切等现象的前提下,用五轴加工中心加工出了叶轮.本方法也适合其他同类型的整体叶轮逆向、设计及五轴数控编程.     

模具自由曲面路径规划技术的研究

随着制造业的迅速发展,用户对模具曲面的加工也提出了越来越高的要求。短周期、高精度、低成本,已成为满足大众的趋势。因此,复杂曲面的多轴加工和加工过程的优化在模具曲面加工技术中越来越重要。综述了模具自由曲面数控加工技术中的关建技术,分析了传统的数控加工技术的不足,最后探讨了自由曲面加工的发展趋势。     

斜轧球类件轧辊的数控车削加工及误差分析

通过对斜轧轧辊数控加工的分析,确定了斜轧轧辊孔的数控车削加工曲面方程,认为4轴（联动）控制的数控车床可以加工出理想的斜轧球类件轧辊辊形曲面。对2种常用3轴控制的数控车削加工方法进行分析,得出了其加工的数学模型,并对其理论加工误差进行了分析,为3轴数控车削加工控制和减小误差提供了理论指导。     

适应数控加工的空间曲面的建立

论述了适应数控加工B样条曲面建立的方法,指出了B样条曲面具有一、二阶连续的特性,可以用多个曲面片的拼接而组成任意形状的自由曲面,从而解决了数控加工中空间曲面建模的难题,为建立空间自由曲面提供了理论依据.     

自由曲面数控粗加工的一种新方法

提出了一个自由曲面三轴数控粗加工的方法。其中粗加工毛坯体的几何模型由零件曲面线性过渡构造。具体内容包括：加工层的确定，等参数刀具轨迹生成以及圆柱端铣刀的干涉检测等。     

基于UG和Vericut复杂曲面零件设计与加工

为了有效提高复杂曲面零件的加工质量和加工效率,该文首先分析复杂曲面零件数控加工的难点,接着以QQ公仔模型为例,论述了UG和Vericut软件在数控加工中应用过程,包括曲面造型、工艺安排、仿真加工、实体切削验证,结合3轴联动FANUC数控加工中心实现了实际的数控加工。通过实践表明,该方法提高了复杂表面零件表面加工质量,能缩短产品设计与制造时间,提高了生产效率。     

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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