小型壳体零件模型的生成系统

随着数控机床的广泛应用,小型壳体的型腔在数控机床上的加工应用越来越广泛。针对这一企业需求,主要介绍了用Visual Basic 6.0调用SolidWorks为其提供的API(应用程序接口)功能进行针对小型壳体零件的二次开发。在对壳体零件模型库的自动建模原理和关键技术详细研究的基础上,开发了基于SolidWorks的采用自动设计与人机交互设计相结合的壳体零件快速设计原型系统。利用特征参数,实现了在SolidWorks界面下自动建立小型壳体模型系统的技术,并且以菱形型腔壳体为例,对开发技术的关键部分进行了详细地论述。     

数控机床数据传输方法应用

随着我国现代制造业发展，数控机床的占有率越来越多，零件的复杂程度也越来越高，在CAM软件自动编程时生成的零件加工程序也越来越大，在程序传输中需要采用数据传输功能。本文主要针对数控机床数据传输，结合自己的工作经验以FANUC系统为例介绍数控机床数据传输的方法。     

数控机床再调整过程的图解模拟

《数控机床再调整过程的图解模拟》一文针对最简单的大量设备系统即数控机床再调整过程进行研宄，分析研究数控机床调整所需要零件开始预定完成期待的工作时间和机床占用时间，并对数控机床在不同时刘状态（手动I——CMO型和自动II——CMO型系统）的再调整不同实例得出不同的数据，从而建立图解模型，并确定了许多重要指标，得出在变更加工零件品种时，数控机床调整时间是影响柔性制造系统效率的重要因素。     

基于UG NX的烟灰缸设计与加工模拟研究

烟灰缸属于型腔类零件曲面复杂,常规的设计与加工效率低,在UG NX的建模和加工模块下对零件的三维辅助设计和三维辅助制造,实现了对型腔类零件的数控仿真加工,最后生成的数控加工代码在经过少量修改后可输入数控机床进行相应零件的加工,极大地减少了手工编程需要的时间,提高了生产效率。在对零件模拟加工时,能及时观察出操作上的问题并及时解决,避免了在实际加工时的错误.     

极坐标数控机床平旋盘底座的有限元分析

针对大型壳体类零件的加工,研究设计了新型的极坐标式数控机床.采用ANSYS软件分析了其底座的动、静态力学特性,验证了设计的可靠性.同时也找出了结构的相对薄弱环节,为底座结构优化设计提供了技术支持.     

数控机床主轴控制系统的设计

针对数控机床主轴控制问题，设计了一个控制系统，并对该系统的实现方法进行了较详细地阐述。     

系列产品的参数化造型与自动拼装

结合国家“八五”项目“重型数控机床模块化设计与制造系统”，在Ｉ—ＤＥＡＳＶＩ—ｉ环境下研究并实现了零件的参数化造型与自动拼装．通过创建特征而记录整个设计过程．一个特征对应多个数据文件，从而生成不同规格零件的实体模型来实现参数化的目的．根据零件在装配中的姿态造型，装配实质是对零件进行定位操作．产品的层次结构使装配过程限制在一定数量的装配对象范畴内，使自动装配的过程易于实现．参数化造型与自动拼装节省了大量的存储空间，免去产品设计人员的重复劳动，提高生产率     

基于 SolidWorks 的陶瓷模具参数化设计

为了深化CAD应用,提高我国陶瓷墙地砖模具系列化、快速化设计效率,研究在VC＋＋6.0二次开发环境下基于SolidWorks的陶瓷墙地砖模具参数化设计方法．在分析SolidWorks应用程序开发接口、ATL技术、参数化建模技术、数据库建立与访问关键技术的基础上,以开发出的陶瓷墙地砖模具参数化设计系统为例,详细说明实现模具零件参数化设计的过程,并给出主要程序代码．实现了相似零件的快速设计,为陶瓷模具及其它行业企业的参数化设计系统二次开发提供了参考．     

基于特征建模技术的楔横轧模具CAD系统研究

为了满足先进制造系统的要求进行了楔横轧模具特征建模的研究，阐述了关于特征建模的设计思想。针对楔横轧零件的特点，在SolidWorks2000平台上二次开发了基于特征建模技术的模块化，参数化的模具CAD系统。     

基于SolidWorks二次开发的零件三维参数化设计及装配

介绍了用VC++作为工具对SolidWorks二次开发的基本原理,研究了以DLL方式开发的基本方法。改进了非标准零件的参数化设计方法,为标准件创建零件库并完成零件自动装配。从而加快产品设计过程,提高效率。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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