“工程材料”课程教学方法改进探析

＂工程材料＂课程是机械设计制造及其自动化专业一门重要的专业基础课。文章分析课程在教学过程中出现的各种问题,提出几点教学方法改进意见：重点抓住＂材料结构决定材料性能＂进行教学,不同材料对比分析教学,课程教学与实践教学紧密结合。通过以上改进,希望能够提高学生学习积极性,培养其分析并解决实际问题的能力。     

A nano to macroscale study on structure-mechanics relationships of archaeological oak

Mechanical properties of wood at different length scales of its hierarchical structure are governed by structural and compositional properties on smaller length scales. This opens up the possibility to use microstructural data for estimating mechanical properties, which are difficult to assess by conventional, destructive testing but are nevertheless of high relevance for conservation practice. Herein, we investigate such microstructure-mechanics relationships for a particular example, namely the load bearing archaeological oak of the Oseberg Viking ship, displayed at the Viking Ship Museum in Oslo, Norway. In order to identify the effects of degradation on the mechanical behavior and their relations to the microstructure, recent oak specimens of different geographical origin (Norway and Austria) are investigated as well. Wood exhibits a cellular structure. Its cell walls are composed of an amorphous polymer matrix consisting of lignin and hemicelluloses and embedded, stiff cellulose fibers. At the cell level, experimental studies comprised microscopic investigations of the cellular structure, chemical analyses of the composition of the cell walls, as well as nanoindentation tests on single cell walls. The same samples were also analyzed on the macroscopic level, where additionally mass density and annual ring data were measured together with ultrasonic stiffnesses. The chemical data clearly indicate deterioration in the archaeological oak, affecting mainly hemicelluloses and amorphous cellulose. At the cell wall scale, however, this does not necessarily lead to a weaker material behavior. The nanoindentation modulus, as a measure of the cell wall stiffness, was found to even increase. This is counterintuitive to our understanding of the effects of chemical degradation. It might be due to possible modification of lignin in the Oseberg oak, and thus have a stronger effect on the indentation modulus than the concurrent weakening of the interfaces between the load-carrying cellulose fibers and the connecting cell wall matrix when analyzing wood at the microscopic level. A similar effect is also observed for the transversal stiffness of macroscopic samples, which increases. In tension-dominated loading modes, however, the degradation of the interfaces is the dominant effect, resulting for example in a considerable reduction of the macroscopic stiffness in longitudinal direction. This underlines the utmost relevance of the loading condition on the remaining load-carrying capacity of degraded wood. On the macroscale, effects of the geographical origin (i.e. growth conditions) on ring characteristics of the oak tissues override the effects of degradation on the mechanical behavior. They have to be carefully extracted in order to come up with conclusions on the effect of degradation from macroscopic test results. The identified microstructure-mechanics relationships provide the basis for–in further research steps–building mathematical models describing the relations between microstructural characteristics and macroscopic mechanical properties and, thereon, for structural analyses of historical wooden objects.     

对日本冈山大学图学教育状况的思考

本文介绍了日本冈山大学制图课的教学状况,进而论述了相应得借鉴意义。     

Pro/E在《机械制图》多媒体课程教学中的应用

Pro／E是近年来迅速推广应用的三维CAD软件,在教学改革中,将其与机械制图有机地结合起来,使课堂教学变得形象、直观,并可激发学生的学习兴趣,在提高学生的空间想象和思维能力方面,达到了较好的教学效果。     

“机械设计”课程教学模式探索

“机械设计”是高等院校面向机类、近机类工科专业开设的专业基础课,是培养学生综合设计能力、创新能力的重要环节。文章根据本科应用型技术人才的培养要求,结合本科学生的教学实践,并考虑“机械设计”课程内容及其特点,提出了授课内容、授课形式、考核方式、教师培养与评价标准等教学改革方法与思路,对于促进学生综合设计能力和技术创新能力的提高以及教师教学水平的提高等方面有着重要的意义。     

谈职业教育中《工程力学》教学思想的变革

在力学教学中，透过现象揭示本质，展示力学美，渗透人文文化，通过这些方法激发学生的学习兴趣，培养学生的创造意识。     

在减速器测绘中学习润滑方法

减速器测绘是机械制图课程的实践教学环节。在教学过程中,由于学生对润滑知识的空白和减速器教学模型存在缺陷等原因,学生在测绘中对涉及润滑部分的原理结构不清楚,产生了很多疑问,直接影响到测绘的教学效果。针对这一问题,本文对减速器润滑原理及润滑部分的主要结构进行了阐述。     

机械制图课程改革设想

本文从机械制图课程改革背景入手，根据机械制图课程改革的基本思路，从完成机械制图与计算机绘图课程整合、保证制图教学时数、培养学生自主学习能力、加强制图技能训练及改革制图考试方法等方面对机械制图课程改革进行了探讨。     

《机械设计基础》课程设计分层教学初探

本文提出了《机械设计基础》课程设计分层教学的思想，阐述了分层教学的理论依据与具体的实施模式。分层教学在该院“机械制造工艺及设备”专业学生中进行了实践探索，从而进一步验证和推究了其科学性。     

“Top-Down-Top”机械制图Ⅱ教学改革研究

基于"整体—部分—整体"的认识论,按照"Top-Down-Top"组织架构将机械制图、机械测绘、三维建模进行知识融合对机械制图Ⅱ进行教学改革,形成"项目式"课程。根据新的教学内容组织进行了教学大纲与教学计划的修订,借助一体化的教学环境与教学资源,采用多样化教学手段进行教学实施,提高了学生的学习兴趣,促进了理论知识的掌握,提高了学生的绘图技能,培养了学生的创新实践意识。