一、常用绘图工具和仪器的使用 （一）图板 图板主要用来固定图纸。它一般是用胶合板制成，板面光滑平整，四边由平直的硬木镶边，其左侧 边称为导边。常用的图板规格有 0 号、1 号和 2 号

1．教学重点 视图的表达 2．难点 局部视图的画法

一、机械制图实训的地位和任务 机械制图是工科院校中一门实践性较强的技术基础课，图示方法的掌握、制 图标准的应用、绘图技能的提高、制图和读图能力的培养以及空间想象能力的增 强，都是通过制图习题和作业要求来实现的。认真完成制图习题和作业是学好本 课程的关键，因此本课程要求学生积极独立完成习题和作业。机械制图实训的目 的是培养学生的投影能力、表达能力、绘图能力、读图能力和计算机绘图能力， 同时，它又是学生学习后续课程和完成课程设计、毕业设计不可缺少的基础

点、直线、平面是构成物体的基本几何元素，研究它们的投影，可提高对物体投影的分 析能力和空间想像能力，解决复杂物体画图及读图中的问题

一、图板、丁字尺、三角板 图板用作画图时的垫板，要求表面平坦光洁；又因它的左边用作导边，所以左边必须平 直。 丁字尺是画水平线的长尺。丁字尺由尺头和尺身组成，画图时，应使尺头靠着图板左侧 的导边。画水平线必须自左向右画，如图 1—1 所示。 图 1—1 图板和丁字尺

计算机绘图基本知识 图块与外部参照 尺寸与文字标注 二维图形编辑 显示控制与辅助绘图 二维图形绘制 AutoCAD基本操作 工程CAD实例 三维图形绘制

Part I Warming Up A Words and Phrases You are going to hear some important dates in email history. Supply the missing dates and words Great Dates in Email History Date: ________________________ Leonard Kleinrock, a UCLA computer science professor, sends the ___________________to a colleague

The true language of computers is a stream of 1s and 0s—bits. Everything in the computer, be it numbers or text or program, spreadsheet or database or 3-D rendering, is nothing but an array of bits. The meaning of the bits is in the “eye of the beholder”; it is determined entirely by context. Bits are not a useful medium for human consumption. Instead, we insist that what we read be formatted spatially and presented

Input devices are those portions of computer, data processing, and information systems that perform the essential function of providing some means for entering commands and data into the system. Therefore, input devices are found in all such systems, but are treated here as a separate equipment group, independent of the

Positional and Polynomial Representations • Unsigned Binary Number System • Unsigned Binary-Coded Decimal, Hexadecimal, and Octal Systems • Conversion between Number Systems • Signed Binary Numbers • Floating-Point Number Systems 86.2 Computer Arithmetic Number Representation • Algorithms for Basic Arithmetic