谈职业院校机械制图教学

“机械制图”课是职业院校机械类通用工种的一门重要的专业技术基础课。它的主要任务是培养和发挥学生的空间思维能力，以便在今后从事零件加工、机械设备安装维修时，能读懂图纸．理解零件各部位之间或各零部件之间的相互位置关系和配合关系，在加工零件时，能正确地进行加工，保证零件各部位处寸达到图纸要求；在安装设备时，确保各部件位置正确，配合间隙达到安装尺寸标准要求；     

仿真（奔驰）西星长头重型卡车纸模制作指南

左图是(奔驰)西星长头重型卡车的照片。下面教你制作仿真(奔驰)西星长头重型卡车纸模。仿真(奔驰)西星长头重型卡车纸模装配示意图1.先沿模型刀版线取下零部件图纸(可以用美工刀帮助取图纸)。2.再按虚线折叠。     

仿真风帆概念自行车纸模制作指南

这是一辆以风能为动力的自行车。现在,让我们一起来制作这辆仿真的风帆概念自行车纸模。仿真风帆概念自行车纸模装配示意图1.先沿模型刀版线取下零部件图纸(可以用美工刀帮助取图纸)。2.再按虚线折叠。3.分别粘贴和组装车身、前后车轮。     

武钢大型厂高线车间1#液压系统图的计算机绘制

1　概　　述　　武钢大型厂高线车间 1 #液压系统包括一个泵站、两个蓄能站、2 1个阀台。该系统目前是由 1 9张三号图纸构成 ,且所有文字说明都是英文 ,因此要浏览整个液压系统就相当麻烦 ,给生产与设备维护带来困难 ,为此厂方要求将这 1 9张三号图纸拼成两张零号图纸 ,并将所有文字说明译成中文。如用传统的手工绘图就存在如下问题 :1、由于该液压系统非常庞大 ,因此在两张零号图纸上很难布局。 2、由于该液压系统有许多相似之处 ,手工绘制导致重复劳动 ,易出错、效率低。基于上述原因 ,我们决定采用 Auto CADR1 4软件进行绘图。2　图纸…     

如何引导中职学生识读建筑施工图纸

教导和引导学生识读单体工程整套图纸——建筑施工图纸、结构施工图纸与设备施工图纸,应把这三套图纸连在一起进行,使学生在施工方面不会出现重复施工或施工完以后由于工艺的要求重新凿开混凝土,避免严重影响建筑产品的质量,造成经济损失。     

机床加工中画几原理的应用

机加工中金属零部件斜孔的加工，经常会遇到工艺转角的问题，而图纸中又往往不宜杯出定位，使加工中不宜加工；本文通过应用画法几何原理，采用投影变换的方法，用图解法以及计算方法来求出其工艺转角的实际大小，以便于加工定位，解决了金属零部件结构上的斜孔在工艺加工方面的问题。     

环保型概念车纸模制作指南

环保型概念车纸模型装配示意图 1.先沿模型刀版线取下零部件图纸(可以用美工刀帮助取图纸). 2.再按虚线折叠. 3.分别粘贴和组装车身、前后车轮等部件. 4.用身边的废纸或吸管、笔芯等材料自制车轴. 5.最后,参照总装示意图制作完成整个纸模.     

基于Solidworks三维建模的制图测绘教学改革探索

针对高职院校机械类专业开设的制图测绘实训课程,分析了目前制图测绘教学中出现的学生忽视测量准确性、零部件表达不准确、疲于完成图纸绘制等问题,提出了将三维建模引入制图测绘教学,利用三维模型与二维图纸的转换提升零部件表达的准确性、利用三维装配来约束零件尺寸测量的准确性,同时由三维模型直接生成二维工程图,大大提高了绘图的速度和准确度,也符合现代设计理念。     

零部件贸易研究现状

在中国的组装与加工贸易中,特别引人注目的是中国零部件贸易与中间产品贸易的发展。加入WTO以来,中国的零部件进出口从2001年的2972.9亿美元增长到2011年的6639.9亿美元,增加了123.4%。零部件贸易已经构成了中国商品贸易中的重要组成部分。对零部件贸易的研究与解决,对中国的未来贸易战略选择无疑具有重要的理论与现实现实意义。     

仿真风帆概念自行车纸模制作指南

这是一辆以风能为动力的自行车.现在,让我们一起来制作这辆仿真的风帆概念自行车纸模. 仿真风帆概念自行车纸模装配示意图 1.先沿模型刀版线取下零部件图纸(可以用美工刀帮助取图纸). 2.再按虚线折叠. 3.分别粘贴和组装车身、前后车轮. 4.用身边的废纸或吸管、圆珠笔芯等材料自制车轴. 5.最后参照总装示意图制作完成.     

论数字化学术期刊

学术期刊数字化、网络化已经成为网络上很普遍的存在。大量充斥因特网的学术期刊网页、网站,看似繁华,其实,它的生存状态很艰难。即使目前学术期刊通过网页或是网站参与学术资源的传递,也只是在原有期刊工作模式下的一些补充,还不能被视为“网络期刊”。数字化学术 解决的问题很多,包括谁来的数字化运作付费、平面期刊网络化的技术、学术资源检索的工具和检索模式的合理化等,只有突破这些“瓶颈”问题,学术期刊的数字化才会真正取得进展。     

云计算在教学中的应用研究

介绍了云计算的基本概念、特点和应用模式,分析了传统教学模式存在的若干不足,给出了基于云计算的解决方案。提出了基于云计算的学习和交流平台的构建方案,以及基于云计算的实验平台构建方案,提出了云计算环境下高校教学模式改革的思路。     

图的连通分支数的邻接矩阵判定

连通性是图的基本性质之一,由定义来判断顶点数和边数较大的图的连通性和连通分支数比较困难。结合图的邻接矩阵,给出判断图的连通性的两个充要条件,并给出判断图的连通分支数的一个充要条件和非负对称不可约矩阵的一个充要条件。     

Putting Rubrics to the Test: The Effect of a Model, Criteria Generation, and Rubric-Referenced Self-Assessment on Elementary School Students' Writing

The purpose of this study was to investigate the effect of reading a model written assignment, generating a list of criteria for the assignment, and self-assessing according to a rubric, as well as gender, time spent writing, prior rubric use, and previous achievement on elementary school students' scores for a written assignment (N = 116). Participants were in grades 3 and 4. The treatment involved using a model paper to scaffold the process of generating a list of criteria for an effective story or essay, receiving a written rubric, and using the rubric to self-assess first drafts. The comparison condition involved generating a list of criteria for an effective story or essay, and reviewing first drafts. Findings include a main effect of treatment and of previous achievement on total writing scores, as well as main effects on scores for the individual criteria on the rubric. The results suggest that using a model to generate criteria for an assignment and using a rubric for self-assessment can help elementary school students produce more effective writing.     

基于模糊控制策略的动态自适应制冷系统

通过对制冷系统的建模与分析,建立工业制冷系统的仿真结构模型,并设计一种基于模糊控制理论的工业制冷系统控制器,进行仿真实验,结果表明,所设计的模糊控制器在受制冷物品干扰和人为调节温度的情况下,效果良好。     

Debating debating: a reflection on the place of debate within secondary schools

This article is based on the authors' reflections on observations and interviews with students and staff involved in a debate competition in London secondary schools. Taking the data we collected as our starting point, we seek to draw on research from a range of perspectives, including political education, political philosophy and debate as a teaching method, to clarify the role of debate within a pedagogy for democracy. We consider the case for promoting debate in general terms, and then go on to discuss the role and form debate should take in such a pedagogy. Here we contrast models based on adversarial and deliberative democracy and consider the need for teachers to be aware of the benefits and shortcomings of each. We then draw on the concept of students' public voice to discuss some of the issues that need to be borne in mind when developing these strategies in class. Finally we pose a number of questions for future investigation, which may help teachers reflect on their own practice as well as inform our own ongoing research in this area.     

Comparing balance and inverse methods on learning conceptual and procedural knowledge in equation solving: a cognitive load perspective

We examined the use of balance and inverse methods in equation solving. The main difference between the balance and inverse methods lies in the operational line (e.g. +2 on both sides vs ?2 becomes +2). Differential element interactivity favours the inverse method because the interaction between elements occurs on both sides of the equation for the balance method but only on one side of the equation for the inverse method. In an experimental study, 63 students (mean age = 13) were randomly allocated to either balance or inverse group to undertake a pre-test, study an instruction sheet, complete acquisition equations, sit for a post-test and a concept test. Procedural knowledge was assessed on performance on practice equations and post-test, whereas conceptual knowledge was assessed on performance on the concept test. The inverse group outperformed the balance group on practice equations but not the post-test. Both the balance and inverse groups scored higher on the inverse concept test than the balance concept test. Positive association between performance on procedural knowledge and performance on conceptual knowledge was found for the inverse group but not the balance group. Overall, the evidence obtained indicates a number of educational implications for implementation.     

函数在一点的可导性与在该点附近的导数的关系

本文通过研究函数在一点的可导性与函数在该点附近的导数的关系,得出了函数在一点可导的一个充要条件,并通过举例说明了它在研究分段函数在其分段点的可导性方面的运用。     

Learning by the Sun: Observing Seasonal Declination with a Vertical Sundial

We designed and constructed a sundial for the purpose of observing the declination of the sun and thus marking solar seasonal variation. The 122 × 122 cm vertical sundial on the south-facing wall of our library has two unusual features: a nodus on the gnomon that casts a shadow of a point for marking the height of the sun and a large blank working space for students to mark the shadow of the nodus at different hours of the day and to connect the marks of 1 day in a line of declination. We discuss the design of a dial that emphasizes a working space for observations on solar declination, methods for determining the position of the nodus such that lines of declination can be observed every day of the year, mathematical procedures that minimize error in laying out the hour lines for this unusual design, the type of materials that are best suited for this design, and how students in an interdisciplinary honors colloquium on seasonal rhythms used the sundial. We also include two appendices on general sundial construction that indicates the information designers need to construct their own sundials.