1.深入理解应力、应变的概念;熟练掌握虎克定律。 2.理解从变形协调、物性与静力学三方面分析由内力求应力的材料力学基本方法。 3.掌握横截面上正应力的一般表达式。 4.熟练掌握拉压杆横截面上正应力、平面弯曲正应力、斜弯曲正应力的计算与分布规律

第一节 天然饮水中的细菌及其分布 第二节 水中的病原细菌 第三节 大肠菌群和生活饮用水标准

Step One: Leading-in Activities: 1. Watch the short movies of Chaplin. 2. Discussion: (1) What do the famous people's lives look like in your eye? (2) Do you want to be famous one day? Why or why not? And (3) What do you usually do in your

本讲主要内容： 置换密码（列置换密码和周期置换密码） 代换密码（单表代换密码、多表代换密码和维尔姆密码） 典型传统密码的分析（统计分析法和明文-密文对分析法）

5.1问题的提出和数学模型 一、引例:某企业生产I、Ⅱ两种产品,其生产的参数 如表中所示。在制定生产计划时要考虑如下内容: (1)依据市场反馈信息,I产品出现滞销,预测表明 ,两种产品的生产比例大致保持1:1为宜; (2)设备能力尚有机动的余地,B设备必要时可以加班, 但希望加班时间愈少愈好;A设备较为重要,所以既希望 能力能够被充分利用,同时又尽量少加班;

主持人:好,请武教授马上给咱们带来一场精彩的学术报告,深入浅出的学术报告,叫做“什么是分 岔”。好,有请。 武际可:我今天讲的是关于分岔的问题。分岔在英文叫做 Bifurcation,这个词在中文里头大概有六种 翻译,我看到的有六种翻译,每个含义用词都用得不一样,有的叫分叉、有的叫分枝、还有的叫分歧等等

世界是有序的还是无序的?世界是可预测的吗?世界包括人类是受决定论支配的吗 一代又一代的人们在寻求着这些问题的答案。 1686年4月28日,牛顿发表了伟大的《然哲学之数学原理》一书。自此,人们似乎窥到了宇宙的整 个奥秘。在牛顿理论的引导下,人们取得一项又一项的成功。许多预言获得了验证这一切都似乎表明了宇 宙的规律已经被洞察,蒙在自然头顶上的神秘面纱已揭开。人类已经洞悉了上帝的旨意

grasp the main idea(we should adopt a sensible environmentalism) and the structure of the text(each part containing a contrast) 2)appreciate the various argumentative skills employed in the text 3master the key language points and grammatical structures in the text

At least 90 percent of UFO sightings can be identified as conventional objects, although time-consuming investigations are often necessary for such identification. The objects most often mistaken for UFOs are bright planets and stars aircraft, birds, balloons kites aerial flares, peculiar clouds, meteors and satellites. The remaining sightings most likely can be attributed to other mistaken sightings or to inaccurate reporting hoaxes or delusions although to disprove all claims made about UFOs is impossible

Objectives Students will be able to: 1. understand the main idea(cloning is a two- edged sword) and structure of the text; 2. appreciate the writing strategies employed by the author, 3. master the key language points and grammatical structures in the text;