圆柱蜗形分度凸轮的加工及应用

本文讨论了圆柱蜗形分度凸轮的实用加工方法。用θ-X 二轴数控加工,再经修研作圆弧修正的工艺方法已加工出合格的分度凸轮。提出了用范成法实现θ-X-Y 三轴加工余弦运动规律的圆柱蜗形分度凸轮;已设计出简单实用的范成装置,在普通铣床上便可实现分度凸轮的加工。设计制造出的圆柱蜗形分度凸轮已成功地应用在研制的盖垫同心贴复合膜高速自动机上。本文还论述了圆柱蜗形分度凸轮可作为自动装配机回转工作台的关键组件。     

弧面分度凸轮机构压力角的通用表达式研究

针对弧面分度凸轮机构参数缺乏通用数学模型的情况,应用包络面理论,通过齐次坐标的矩阵变换,提出了一种基于统一数学表达的弧面分度凸轮轮廓曲面的建模方法.以圆柱滚子、圆锥滚子和双曲线滚子为研究对象,推导建立了弧面分度凸轮廓面模型的统一数学模型,在此基础上进一步推导出了压力角的通用解析表达式,为弧面分度凸轮的精确设计与制造提供了理论基础.     

圆柱分度凸轮机构误差研究

采用作用线增量法,对影响国柱分房凸轮机构分度误差的各误差因素进行了分析求解,为圆柱分度凸轮机构的精度分析与研究提供了依据,从而可以控制与调整影响该机构的各个误差因素,提高国柱分度凸轮机构的分度精度.     

基于Solidworks圆柱凸轮三维参数化设计的实现

本文利用VB程序,基于SolidWorks平台,阐述了实现圆柱凸轮三维参数化设计的关键点,实现从动件不同运动规律的圆柱凸轮的建模和设计。提供了一种对三维CAD软件二次开发的方法,具有较强的工程实用性。     

两轴联动数控加工圆柱分度凸轮的理论制造误差分析

介绍了两种联动数控加工圆柱分度凸轮的编程坐标换算方法，导出了两轴动加工理论制造误差计算公式，结合实例进行了误差分析，对圆柱分离凸轮廓形的数控加工具有指导意义。     

B样条在弧面分度凸轮设计与制造中的应用

介绍了一种新的基于B样条曲线的弧面分度凸轮的设计与制造技术,给出了两种构造凸轮从动件运动特征曲线的方法优化设计法和拟合法.讨论了用它们构造凸轮从动件运动曲线的特点和注意事项,提出了用B样条插补加工弧面分度凸轮的方法,并开发了相应的设备,提高了弧面分度凸轮的制造质量.     

圆柱滚子球面凸轮轮廓曲面的设计

用球面坐标建立了圆柱滚子球面凸轮的轮廓曲面解析方程，为此种凸轮的设计计算和数控加工提供了理论依据。     

圆柱分度凸轮非等径数控加工自动编程

圆柱分度凸轮廓形的非等径加工自动编程 ,能够及时有效地补偿刀具尺寸的变化 ,保证加工精度 ,降低刀具费用。介绍了在三轴联动数控机床上加工圆柱分度凸轮时 ,非等径加工的刀位点的确定、刀位点轨迹及编程坐标计算 ,并给出了非等径加工程序实例     

圆柱凸轮的CAD/CAM

凸轮机构是机械工业中常见的运动机构。但在传统的机械制造技术中,由于受到设计和加工条件的限制,往往只能采用作图法设计凸轮轮廓、采用划线加工的方法加工凸轮,这使得其应用范围和应用水平都受到限制,尤其是圆柱凸轮的设计和加工。本文介绍了一种用VC＋＋6.0开发的能通过输入相关的参数来设计圆柱凸轮并自动生成凸轮加工数控程序的软件。     

平行分度凸轮机构参数分析

平行分度凸轮机构是自动机械中实现间歇步进运动的关键部件,在食品、药品、印刷等行业得到广泛的应用。以广泛应用于步进自动化机械系统中的平行分度凸轮机构为对象,针对平行分度凸轮机构的结构特点和传动原理,对该类机构的主要设计参数进行了分析。通过对三种不同的运动规律的比较,选择了合适的运动曲线,形成了凸轮的廓线。另外,分析了外径条件、压力角条件、根切条件等凸轮轮廓的制约条件。     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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