工程制图智能电子习题集软件系统的设计与实现

对工程制图智能电子习题集软件系统的设计进行了深入探讨,分析了对图形支撑平台系统的要求,提出一个开放的由习题库、答案库和习题三维模型库组成的电子习题集图形库系统;对工程制图作业的智能批改策略进行了深入探讨,包括工程制图习题作业自动批改要求、自动批改处理策略及一个基于图形特征结构的智能匹配的图形几何匹配方法;提出一个基于正向推理的图形匹配识别算法。     

工程制图虚拟模型室的建立与应用

针对工程制图教学的需要,以Inventor软件为基础建立了一个工程制图虚拟模型室,补充与丰富了传统的实物教学模型。介绍了零件造型特征、自适应技术和工程图的生成,并说明了一般零部件的设计方法和流程,最后介绍了模型室的管理。     

基于Web的工程制图助学型CAI

针对当前工程制图CAI课件类型单一、网络课件相对滞后等缺陷，从画法几何及工程制图教学的实际需要出发，以课程中的三大主要内容，即“画法几何”、“制图基础”、“机械制图”为教学目标，设计开发了基于网络的工程制图助学型CAI系统。介绍了系统的总体构成、设计制作工具和系统实施的主要技术策略。     

工程制图协同学习系统设计与开发

根据工程制图的教学特点,设计并开发一个多媒体"工程制图"多媒体网络互动系统.描述根据设计目标而设计系统的结构,对支持整个系统的几个功能模块的主要技术特点和关键技术进行研究和分析,突出强化互动设计,促进工程制图教学的显著特点.     

工程制图中教学难点的"体验教学"设计

“体验教学”是一种适应新经济时代人才培养模式需要的新的教学理念。在此理念指导下,作者以营造“体验”环境,建构由低级向高级过渡渐次递进的“体验”历程为手段,应用最新的JAVA3D技术设计了工程制图模型的参数化虚拟实验系统,并针对工程制图中的教学难点,即截交线和相贯线进行了相关的“体验教学”设计。     

工程制图课程的工程性改革实践

在教学内容上,分析了现代工程图学的教学要求,提出了工程制图课程新的教学体系.在教材上,以贯彻国家标准为出发点,重新组织了相关教学内容.在教学过程中,强调了制图课程的工程性,调动了学生学习工程知识和进行工程实践的积极性.     

浅谈3D制图教学中的二维表达

分析了现代设计的需求,对三维制图教学与传统制图教学进行了对比,指出了二者的差别.强调将三维设计的相关内容引入工程制图教学的必要性,并认为以三维为主导的制图教学中,有效加强二维表达是教学改革的切入点,亦是实现传统制图教学向三维制图教学过渡的有效途径.同时指出加强二维表达应注意的几个问题.     

高职学生工程制图学习障碍及对策研究

《工程制图》是工程类专业的一门必修的技术基础课，是表达和交流技术思想的工具，对它掌握的好坏直接影响着学生的制图技能。文章对高职学生工程制图学习障碍的成因进行了分析，并根据笔者的教学实践提出了高职院校学生工程制图学习障碍的应对策略，为高职院校工程制图的教学改革提供理论和实践的参考。     

土木类工程制图课程的双语教学模式探索与实践

在分析国内双语教学实施必要性的基础上,针对双语教学在高校实施过程中出现的问题,从教学方法、工程制图课程教材两个方面进行探讨。通过总结作者在工程制图双语教学实施过程中所采取的措施和方法,给出了课前印发课程提要以克服学生畏难情绪、构建互动式课堂环境引导学生踊跃发言、鼓励学生进行自主设计三种调动学生学习积极性的教学建议,为学生营造出能够体现英语及制图课程应用价值的课堂氛围,以提高工程制图课程双语教学效果。     

工程制图网络习题集及智能批改系统的研究

分析了工程制图网络习题集及智能批改系统的基本功能,介绍了该系统的界面及系统的架构,并就系统的数据库设计进行了分析,给出了智能批改的实例。在所设计的系统中用户可以在客户机上登陆远程服务器,从服务器上的题库中下载题目。在 AutoCAD绘图环境中完成作业后,立即可以提交到服务器上的作业库中,并可以随时查得批改后的反馈信息。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

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.     

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.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

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.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

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.     

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.