采煤机截割部建模与动力学仿真研究

采煤机工况恶劣,载荷复杂,使得基于物理样机的试验危险性大且代价昂贵,而利用虚拟样机技术进行建模与仿真研究可以在物理样机产生前对产品的性能进行全面评估,从而获得系统级优化的产品.建立了采煤机截割部刚柔耦合虚拟样机,剖析了基于Pro/E建立三维实体模型、MATLAB模拟滚筒所受冲击载荷、ANSYS制作模态中性文件、ADAMS设置仿真参数等若干关键技术问题,大大提高了基于Pro/E,ANSYS,ADAMS和MATLAB等软件进行多领域建模和仿真的可操作性,对于研究多体系统工作的可靠性具有重要价值.     

Pro/ENGINEER中的汽轮发电机定子绕组三维建模及参数系列化设计

提出了一种利用Pro/E进行汽轮发电机定子绕组参数系列化三维建模的方法.针对汽轮发电机定子绕组端部结构复杂,但成型机理相同的特点,利用Pro/E建立了汽轮发电机定子绕组的三维模型.通过Pro/E的二次开发工具Pro/TOOLKIT,开发了可直接在UI对话框中进行参数设计的应用程序.结果显示,这种方法实现了汽轮发电机绕组参数设计的系列化,可明显缩短开发周期,并得到精确三维模型,整体上优于传统的设计方法.     

基于Pro/E二次开发的机械零件参数化研究与实践

针对Pro/E二次开发的参数化设计技术进行了详细的研究,论述了应用Pro/Toolkit进行菜单开发、三维参数化设计开发的基本方法.利用MFC对话框和 VC++建立螺杆零件参数驱动自动生成技术,开发出与 Pro/E 4.0系统集成的变螺距分件:送料螺杆零件参数化设计系统.对Pro/E的二次开发和零件标准化技术的推广具有较高的实用价值.     

三维测量试验样机结构虚拟设计

 根据三维测量系统要求设计了中刀结构和轴承结构方案，为便于通过试验手段比较这2种方案的性能优劣，对试验样机提出了各种设计要求。制订了具体的虚拟设计流程，基于Pro/E软件建立了参数化实体模型，循环进行了有限元静力学分析和重心坐标计算等。设计了试验样机的具体结构，分析表明设计结果符合试验样机的各种要求。虚拟设计技术的应用显著提高了设计质量和效率，简化了分析计算过程。该设计流程为其他试验样机的设计提供了参考。     

基于虚拟装配的硬币自动包装机设计方法

为解决硬币处理困难的问题,研究和设计了一种新型台式硬币包装机.在开发过程中采用基于 3D 特征造型和虚拟装配等CAD 技术,应用Pro/E 软件实现了该硬币包装机的三维设计和数字化样机的建立;通过动态仿真和干涉分析,验证了设计方案的可行性.该方法为此种硬币包装机物理样机的制作,和日后产品结构的设计优化提供了快捷有效的途径.     

浅谈Pro/E软件在机械CAD设计中应用

Pro/Engineer是一套由设计至生产的机械自动化软件,是新一代的产品造型系统,是一个参数化、基于特征的实体造型系统,并且具有单一数据库功能。因此,介绍三维CAD软件Pro/E设计手段的优势,阐述Pro/E参数特性及目前推广存在的问题。     

基于Pro/E的压片机参数化设计

利用Pro/E参数化设计功能及其二次开发工具Pro/Toolkit;以VS2008为开发平台,采用面向对象和可视化编程技术,以动态链接库的形式实现了在Pro/E平台下压片机零部件交互式参数化设计的方法.     

三维分形图案自动生成方法及其应用研究

为了实现分形图案计算机辅助三维化设计,以生成产品造型触感装饰效果,提出一种集成Visual C++、AutoCAD、Pro/E的三维分形图案自动生成方法。应用ObjectARX3.0开发了分形图案参数化自动生成软件,可简易获取各种分形图的.dwg(或.dxf)格式文件;在Pro/E软件中调入.dwg(或.dxf),通过其拉伸、扫描和映射等操作实现分形图的三维化设计。实例表明该方法可应用于产品造型设计中立体纹案的设计与实现。     

包装纸盒盒型参数化设计应用程序的开发与实现

为了提高包装纸盒盒型的设计效率,在Pro/E应用软件的基础上,利用其自带的二次开发工具Pro/TOOLKIT,采用对话框资源文件设计技术、程序源文件设计技术和程序注册运行技术,完成了包装纸盒盒型参数化设计应用程序的开发,实现了包装纸盒盒型的参数化设计.     

基于Pro／E的桁架门式起重机丰梁的三维参数化设计的研究

利用Pro／Toolkit对Pro／E2．0进行二次开发,采用三维模型与程序控制相结合的方式来进行参数化设计,并结合SQLServer数据库管理技术,实现桁架门式起重机主梁的三维参数化设计。     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.