3#机械分析题目
ⅲ与3的用法
ⅲ与3的用法
在数学中,罗马数字Ⅲ和阿拉伯数字3具有相似的意义,都表示计数或顺序。
但是,罗马数字Ⅲ通常用于较大的数字,特别是在罗马时代,而阿拉伯数字3则更为通用。
此外,罗马数字Ⅲ还有特定的数学符号意义,例如表示三角形。
- 阿拉伯数字3的用法:
阿拉伯数字3是一个基本的计数和顺序符号,可以用于表示数量、次序或顺序等。
例如,表示数量时可以表示三本书、三个苹果等;表示次序或顺序时可以表示第三名、第三个进球等。
在数学中,3通常用于表示一些基本的数学概念或运算,如三次方根、三角函数等。
- 罗马数字Ⅲ的用法:
罗马数字Ⅲ主要用于较大的计数或顺序,特别是在罗马时代。
例如,罗马帝国的年份和历史事件通常使用罗马数字来标记。
此外,罗马数字Ⅲ也可以用于表示三角形的数学符号,例如直角三角形、等边三角形等。
在科学和工程领域,罗马数字Ⅲ也用于表示一些特定的参数或符号,如质量、体积等。
总之,罗马数字Ⅲ和阿拉伯数字3都是计数和顺序的符号,但在使用上略有不同。
罗马数字Ⅲ主要用于较大的计数和顺序,特别是在历史和科学领域,而阿拉伯数字3则更为通用,在日常生活中更常用。
3在生活中可以表示什么
3在生活中可以表示什么
在生活中,数字3可以表示许多不同的事物和概念。
它是一个有趣而多面的数字,可以在各种场合和情境中被发现。
下面我们来看看3在生活中可以表示什么。
首先,3可以表示团结和和谐。
在许多文化和宗教中,3被视为一个具有特殊
意义的数字。
例如,在基督教中,三位一体代表了上帝的三个位格,父、子和圣灵。
在许多民间传说和神话中,三个兄弟或三个姐妹通常代表着团结和和谐的家庭关系。
因此,3可以被视为一种象征,代表着团结和和谐的力量。
其次,3也可以表示平衡和完整。
在许多领域中,平衡和完整都是非常重要的
概念。
例如,在艺术和设计中,三角形被认为是一种非常平衡和完整的形状,因为它具有三个相等的边和三个相等的角。
在哲学和心理学中,三个要素的平衡和完整性被视为一种理想状态,可以带来内心的平静和满足感。
最后,3也可以表示变化和发展。
在自然界和人类社会中,一切都在不断地变
化和发展。
这种变化和发展通常可以被分为三个阶段,开始、中间和结束。
例如,在植物的生命周期中,种子发芽、成长、开花结果,这三个阶段代表着植物的生长和发展过程。
在人类社会中,许多事物也经历着类似的变化和发展过程,例如家庭的成长、企业的发展等。
综上所述,3在生活中可以表示团结和和谐、平衡和完整以及变化和发展。
这
个数字在我们的日常生活中随处可见,它提醒着我们生活中重要的价值和原则,同时也让我们更加深入地理解世界的本质和规律。
让我们在生活中保持团结和和谐,追求平衡和完整,不断地变化和发展,让自己和周围的世界变得更加美好和丰富。
3的寓意和象征
3的寓意和象征3的寓意和象征一直以来都是令人着迷的话题,它在人们的生活中占据着重要的地位,不仅仅出现在数字、图形、文学、艺术等方面,还深刻影响着人们的思想、信仰和文化。
在这篇文章中,我将详细介绍3的寓意和象征,以及它所代表的含义和影响。
首先,3是一个具有神秘色彩的数字,它既可以代表幸运和成功,也可以代表不幸和厄运。
在苏格拉底哲学中,3被视为灵魂的数字,因为人们的灵魂是由三部分组成的:理智、情感和欲望。
在基督教中,3被视为象征着三位一体的上帝:父、子和圣灵。
此外,3还代表了生命、死亡和再生。
在古埃及神话和其他文化中,3代表了三个阶段的循环:生命、死亡和再生。
因此,3可以被看作是一个象征着生命循环的数字。
其次,3还与创造、平衡和完美相关联。
在美学中,3是一个非常重要的数字。
它被视为最平衡和完美的数字,因为它刚好处在1和5之间。
三角形也是一个具有完美平衡的形状。
许多艺术品中都有3的影子,例如三原色、三分色彩、三分构图等等。
此外,在许多文化中,3还被视为一个神圣的数字,因为它代表了创造力和天赋。
三只乌鸦、三只小熊和三只猪都被视为聪明、勇敢和有才华的动物,在古代也被视为象征着精灵和神仙。
最后,3还代表了联合、和谐和团结。
这一点在许多文化中都非常明显。
在儒家文化中,三才是社会组织的基础,三纲五常是家庭道德的基础。
在希腊神话中,三姐妹毕斯提斯是命运女神,代表着联合、平衡和团结。
在印度教中,三位主神布拉马、维希努和湿婆代表着三种“神圣能量”,这些能量一起形成了宇宙的平衡和谐。
3的寓意和象征是多种多样的,每个人对于3的理解也是不同的。
它可以代表幸运、成功、生命、创造力、和谐、团结等等,这些都是人们追求的目标。
同时,3也可以代表着不幸、痛苦和困难,对于这些挑战,我们需要勇敢地面对和克服。
因此,3不仅是一个数学数字,也是一个哲学概念和文化符号,渗透在人们的生活和思维之中。
它给我们带来了深刻的启示和思考,也让我们惊叹于数字和生命的奥秘。
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全新版大学英语综合教程3UNIT 4单词
• n. 列; • 栏,专栏; • (圆)柱; • 纵队,直行 E.G : A column of soldiers were marching down the road. 一队士兵沿路走去
column
bug
• V 长大,使突出; 打扰,烦扰; E.G : This little guy really bugged me. 那个小家伙实在令我恼火 在……装窃听器 E.G : She suspected that her phone had been bugged. • N 虫子,臭虫; 小病,(机器)故障; 窃听器
appearance
• (n. 外貌;出现 • to all ~s 就外表来看,根据观察推测。 • E.g : He did not answer and was to all appearances asleep. 他没有答话,看来 是睡着了 • 【反】disappearance 失踪,消失,不 见
• phrase: in the blink of an eye就在眨眼之间 on the blink出毛病 eg:If a machine goes on the blink, it stops working properly.
regardless
1.prep phrase 不顾;不管;不论 Regardless of whether he is right or wrong, we have to abide by his decisions 2.adv.不管怎样;无论如何;不顾一切地 Despite her recent surgery she has been carrying on regardless.
wit
make like
3的数字代表什么意思有什么含义
3的数字代表什么意思有什么含义数字“三”无论是西方还是在中国都被作为神秘的象征。
那么,你知道3的数字代表什么意思吗?接下来就跟着店铺一起去看看3的数字代表含义吧。
3的数字含义数字3的含义:表达数在两个对立之间有著抽象或灵性的关系,例如阴和阳并不是一种关系,爱或欲望必须存在,这样才会有所谓的关系出现,关系的建立是存在于两端之内的第三股力量,对立的和解是宇宙中第三力量。
三的扮演角色,在“三位一体”中得以认知,这在古埃及或世界上其他的神话(例如____的三位一体)中出现。
数字3拥有极高的表达天赋,他们会非常乐意跟人交流自己的想法,也会非常喜欢各种社交关系带给自己的新鲜感。
他们喜欢在人群中表现自己,由于他们对情绪拥有极强的感受力,天性中又带着浪漫快乐的一面,所以他们时常会成为朋友圈内调解气氛的快乐源泉。
数字3的含义关键词:沟通、社交、快乐象征符号:三角型属性:灵巧聪慧型对应色彩:黄色五行:阳火星座排行:双子、双鱼数字3在形态上是个多方位的“可爱数”,把3侧翻过去就是英文字母E,躺下又像是W,趴下看又成了M,这是阿拉伯数字里最有趣的一个数。
3代表关系,黑与白无法直接关联,阴和阳必须同时存在,关系的建立是第三种力量。
1是父亲,2是母亲,而3就是它们的“孩子”。
在____中,3是圣父、圣子和圣灵的综合体,即男性驱动力+儿童状态+灵性结合三位一体数。
这是一个乐观机敏的数字,具有旺盛的好奇心,乐观善于表达,具备孩子一般的纯真与多变性。
正面优势聪明,热情,想象力丰富,有创意,幽默感,充满活力,善于表达,时尚,擅社交,沟通,多才多艺,有趣,乐观,有激情,受欢迎负面挑战夸张,缺乏责任心,做作,缺乏方向,自我怀疑,搬弄是非,幼稚,逃避现实,肤浅,虚荣浮华,喋喋不休,撒谎,铺张浪费恐惧被限制,无聊,面对现实,不被关注数字3的象征意义数字“三”无论是西方还是在中国都被作为神秘的象征。
“三”在符号象征体系中,几乎不含任何反面意义,其象征意义涉及到宗教思想、传统、神等诸多领域。
由三个不同的英文字母和三个不同的阿拉伯数字组成一个
一般模型: 一般模型
个元素, 从4个不同的元素a、b、c、d中取出 个元素,然 不同的元素 中取出3个元素 后按照一定的顺序排成一列,共有多少种不同的排法? 一定的顺序排成一列 后按照一定的顺序排成一列,共有多少种不同的排法?
由此可以写出所有的排列:
abc adb bca cab cda dba
abd adc bcd cad cdb dbc
练习
练习2 练习2.在A、B、C、D四位候选人中,选举 四位候选人中, 四位候选人中
正、副班长各一人,共有几种不同的选法?写出所 副班长各一人,共有几种不同的选法? 有可能的选举结果. 有可能的选举结果. 解:选举过程可以分为两个步骤. 选举过程可以分为两个步骤.
步选正班长, 人中任何一人可以当选 人中任何一人可以当选, 种选法 种选法; 第1步选正班长,4人中任何一人可以当选,有4种选法; 步选正班长 步选副班长, 人中任一人都可以当选, 第2步选副班长,余下的 人中任一人都可以当选,有3 步选副班长 余下的3人中任一人都可以当选 种选法. 种选法. 根据分步计数原理,不同的选法有: 根据分步计数原理,不同的选法有: 4 ×3=12(种). = ( 其选举结果是: 其选举结果是: AB AC AD BC BD CD BA CA DA CB DB DC
问题1 从甲、 问题1 从甲、乙、丙3名同学中选出 名参加 名同学中选出2名参加 名同学中选出
某天的一项活动,其中1名同学参加上午的活动 名同学参加上午的活动, 某天的一项活动,其中 名同学参加上午的活动, 1名同学参加下午的活动,有多少种不同的方法? 名同学参加下午的活动, 名同学参加下午的活动 有多少种不同的方法? 元素: 元素:被选取的对象 一般模型: 一般模型: 个元素, 从3个不同的元素 个不同的元素a,b,c中取出 个元素,然后按照一 中取出2个元素 然后按照一 定的顺序排成一列 一共有多少种不同的排列方法? 排成一列, 定的顺序排成一列,一共有多少种不同的排列方法?
《听力教程3》听力原文及参考答案
《听⼒教程3》听⼒原⽂及参考答案Book ThreeUNIT 1Section OnePart 1Spot DictationHouses in the FutureWell, I think houses in the future will probably be (1) quite small but I should think they'll be (2) well-insulated so that you don't need so much (3) heating and (4) cooling as you do now, so perhaps very economical (5) to run. Perhaps they will use (6) solar heating, although I don't know, in this country, perhaps we (7) won't be able to do that so much. Yes, I think they'll be full of (8) electronic gadgets: things like very advanced televisions, videos, perhaps videos which take up ... the screen (9) takes up the whole wall. I should think. Yes, you'll have things like (10) garage doors which open automatically when you (11) drive up, perhaps electronic (12) sensors which will (13) recognize you when you, when you come to the front door even. Perhaps (14) architects and designers will be a bit more (15) imaginative about how houses are designed and perhaps with the (16) shortage of space people will think of putting gardens (17) on the roof and, and maybe rooms can be (18) expanded and, and (19) contracted* depending on what you use them for, so perhaps there'll be a bit more (20) flexibility about that. Part 2Listening for GistA: Tuesday two fifteen. Let me look inmy diary. B: No, Thursday.A: Oh, I'm sorry. I thought you said Tuesday.B: Thursday two fifteen. No, I'm sorry. I've got an appointment until three. Could we make it later?Say three fifteen?A: Well, there's a lot to talk about. It'll take a couple ofhours, at least. B: Shall we say Monday morning, then?A: Monday morning. All right. Nine o'clock?B: Nine. I think that will be all right. I'll ring you backand confirm. A: All right. But ring before five, couldyou?B: All right.A: Right you are. Bye. B: Bye.Exercise. Directions: Listen to the dialogue and write down the gist and the key words that help you decide.1.This dialogue is about making an appointmentWoman: Listen! I'm terribly sorry I'm late. Man:Man: Oh, that's all right. It doesn't really matter, does it? I haven't got anything better to do, have I?Woman: Just let me explain, will you?Man: I've only been waiting for over an hour. That's all.Woman: Yes. I know, and I would have ...Man: After all, my time isn't really that important, is it?Woman: Please don't be like that. Just let meexplain. (Silence. Man says nothing.)Woman: I ... I tried to get here in time but just after I left home, the car broke down.Man: The car broke down?Woman: Yes, and ... well ... luckily ... there was a garage near me. And ... and it took them a whileto repair it.Man: Why didn't you at least phone?Woman: I would have! But I didn't know the number of the restaurant.Man: You could have looked it up in the telephone book!Woman: Yes, but ... you'll never believe this ... I couldn't remember the name of the restaurant. I knew where it was, but forgot the name.Man: I see. Well, at least it was lucky you found a garage to repair your car. Woman: Yes. It was something I couldn't do myself. It didn't take too long, but that's why I'm late,you see.Man: Uh-huh. Which garage, by the way?Woman: Pardon?Man: Which garage did you take it to?2.The key words are Tuesday. Thursday. two fifteen. three fifteen. Mondaymorning. nine o'clock.Section Two Listening comprehensionPart 1 DialogueI'm terribly sorry I'm late.Woman: Listen! I'm terribly sorry I'm late. Man:Man: Oh, that's all right. It doesn't really matter, does it? I haven't got anything better to do, have I?Woman: Just let me explain, will you?Man: I've only been waiting for over an hour. That's all.Woman: Yes. I know, and I would have ...Man: After all, my time isn't really that important, is it?Woman: Please don't be like that. Just letme explain. (Silence. Man says nothing.)Woman: I ... I tried to get here in time but just after I left home, the car broke down.Man: The car broke down?Woman: Yes, and ... well ... luckily ... there was a garage near me. And ... and it took them a whileto repair it.Man: Why didn't you at least phone?Woman: I would have! But I didn't know the number of the restaurant.Man: You could have looked it up in the telephone book!Woman: Yes, but ... you'll never believe this ... I couldn't remember the name of the restaurant. I knew where it was, but forgot the name.Man: I see. Well, at least it was lucky you found a garage to repair your car. Woman: Yes. It was something I couldn't do myself. It didn't take too long, but that's why I'm late,you see.Man: Uh-huh. Which garage, by the way?Woman: Pardon?Man: Which garage did you take it to?Woman: Uh ... the one near my flat. You know. Lewis Brothers.Man: Yes, I know that garage. It's the only one near your flat.Woman: Hmm, well now, let's have something to eat. Uh, what about some ... Man: I know the garage very well! Woman: Yes. Let's see now. Yes, I think I'll have some ...Man: A pity it's Sunday.Woman: Pardon?Man: A pity it's Sunday. That garage is closed on Sunday!Exercise Directions: Listen to the dialogue and answer the following questions."Well, at least it was lucky you found a garage to repair your car."4.Because she wants to stop the conversation like this.Because he knows the girl is lying.Part 2 PassageThe Oscar Statuette1 Industry insiders and members of the press called the award "the Academy statuette", "the golden trophy" or "the statue of merit", but the term never stuck.2. No hard evidence exists to support that tale, but in any case, by the sixth Awards Presentation in 1934, a Hollywood columnist used the name in his column.3. Walt Disney was honored with one full-size and seven miniature statuettes on behalf of his animated feature Snow White and the Seven Dwarfs.1.T hey are possibly boyfriend and girlfriend.2.In a restaurant.3."It doesn't really matter, does it? I haven't got anything better to do, have I?""I've only been waiting for over an hour.That's all" "After all, my time isn't reallythat important, is it?" well, at least It waslucky you found a barrage to repair yourcar4. If the statuettes don't meet strict quality control standards, they are immediately cut in half and melted down.5.The large boxes are shipped to the Academy offices via air express, with no identifiable markings.The Oscar statuette, designed by MGM's* chief art director Cedric Gibbons, depicts* a knight holding a crusader's* sword, standing on a reel of film with five spokes, signifying the original branches of the Academy: Actors, Writers, Directors, Producers, and Technicians.Born in 1928, years would pass before the Academy Award of Merit was officially named "Oscar". Industry insiders and members of the press called the award "the Academy statuette", "the golden trophy" or "the statue of merit". The entertainment trade paper, Weekly Variety, even attempted to popularize "the iron man". The term never stuck.A popular story has been that an Academy librarian and eventual executive director, Margaret Herrick, thought the statuette resembled her uncle Oscar and said so, and that as a result the Academy staff began referring to it as Oscar.No hard evidence exists to support that tale, but in any case, by the sixth Awards Presentation in 1934, Hollywood columnist Sidney Skolsky used the name in his column in reference to Katharine Hepburn's first Best Actress win. The Academy itself didn't use the nickname officially until 1939.Since its conception, the Oscar statuette has met exacting uniform standards - with a few notable exceptions. In the 1930s, juvenile players received miniature replicas* of the statuette; a ventriloquist* Edgar Bergen was presented with a wooden statuette with a moveable mouth; and Walt Disney was honored with one full-size and seven miniature statuettes on behalf of his animated feature Snow White and the Seven Dwarfs. Between 1942 and 1944, in support of the war effort, Oscars were made of plaster. After the War, winners turned in the temporary awards for golden Oscar statuettes.The traditional Oscar statuette, however, hasn't changed since the 1940s, when the base was made higher. In 1945, the base was changed from marble to metal and in 1949, Academy Award statuettes began to be numbered, starting with No. 501.Approximately 50 Oscars are made each year in Chicago by the manufacturer, R. S. Owens. If they don't meet strict quality control standards, the statuettes are immediately cut in half and melted down.Each award is individually packed into a Styrofoam* container slightlylarger than a shoebox.Eight of these are then packed into a larger cardboard box, and the large boxes are shipped to the Academy offices in Beverly Hills via air express, with no identifiable markings.On March 10, 2000, 55 Academy Awards mysteriously vanished en route from the Windy City* to the City of Angels. Nine days later, 52 of stolenstatuettes were discovered next to a Dumpster* in the Koreatown section of Los Angeles by Willie Fulgear, who was later invited by the Academy to attend the Oscar 2000 ceremonies as a special guest.For eight decades, the Oscars have survived war, weathered earthquakes, and even managed to escape unscathed* from common thieves. Since 1995, however, R. S. Owens has repaired more than 160 statuettes. "Maybe somebody used chemicals on them to polish them and the chemicals rubbed right through the lacquer* and into the gold," explains the company president. "Or maybe people stored them someplace where they corroded." Although he stresses that the statuette is made to endure, Siegel offers this sage advice to all Oscar winners: "If it gets dusty, simply wipe it with a soft dry cloth." Exercise A Pre-listening QuestionEvery January, the attention of the entertainment community and of film fans around the world turns to the upcoming Academy Awards, the highest honor in filmmaking. The annual presentation of the Oscars has become the Academy of Motion Picture Arts and Sciences' most famous activity. The Oscar Statuette is a knight holding a crusader's sword, standing on a reel of film with five spokes.Exercise B Sentence DictationDirections: Listening to some sentences and write them down. You will hear each sentence three times.Exercise C Detailed ListeningDirections: Listen to the passage and decide whether the following statements are true (T) or false (F). Discuss with your classmates why you think the statement is true or false.----I...- 1. There were five original branches of the Academy.(Because the five spokes on the reel of film signify the original branchesof the Academy:Actors, Writers, Directors, Producers, and Technicians.)~ 2. The Academy Award of Merit was officially named "Oscar" in 1928.(Born in 1928, years would pass before the Academy Award of Meritwas officially named "Oscar.")----I...- 3. The Academy staff began referring to the Academy statuette as Oscar because Margaret Herrick said the statuette was like her uncle Oscar.(An Academy librarian and eventual executive director, MargaretHerrick, thought the statuette resembled her uncle Oscar and said so,and as a result the Academy staff began referring to it as Oscar.)4. Since its conception, the Oscar statuette has met exacting uniform standards. (There were a few notable exceptions. In 1930s, juvenile players received miniature replicas of the statuette and a ventriloquist Edgar Bergen gained a wooden statuette with a moveable mouth. Walt Disney was honored with one full-size and seven miniature statuettes. )----I...- 5. Oscars were made of plaster in the 1940s because of the War. (Between 1942 and 1944, in support of the war effort, Oscars were made of plaster.) ----I...- 6. The manufacturer, R. S. Owens makes about 50 Oscars each year in Chicago. (Approximately 50 Oscars are made each year in Chicago by the manufacturer, R. S. Owens.)~ 7. 55 Academy Awards were stolen by a mysterious person en route from the Windy City to the City of Angels on March 10, 2000.(On March 10,2000,55 Academy Awards just mysteriously vanished en route from the Windy City to the City of Angels, but how and by whom was unknown.) ~ 8. For eighty years, the Oscars have survived war, weathered earthquakes, managed to escape unscathed from common thieves and even chemical corrosion.(Since 1995, however, R. S. Owens has repaired more than 160 statuettes. "Maybe somebody used chemicals on them to polish them and the chemicals rubbed right through the lacquer and into the gold."Exercise D After-listening DiscussionDirections: Listen to the passage again and discuss the following questions.1.T he traditional Oscar statuette hasn't changed since the 1940s, when the basewas made higher.In 1945, the base was changed from marble to metal and in 1949, Academy Award statuettes began to be numbered, starting with No.501.2.(Open)Section ThreeNewsNews Item1Bush-NATO-IraqMr. Bush says he hopes America's NATO allies will stand with the United States if he decides to take military action against Iraq.All the same, the president says no action is likely in the near future. He says for now the focus is on implementing the new UN resolution that calls for a tough weapons inspection regime* and warns of consequences if Iraqi leader Saddam Hussein fails to comply*.Administration official say they expect the NATO summit to release a political statement backing the UN resolution. They say President Bush will bring up Iraq in his bilateral meetings in Prague*, but they also say they do not believe the Iraqi threat will be the focus of the summit.In Prague, the alliance plans to take steps toward the creation of a rapid deployment force that can playa role in combating terrorism. The president said even the smallest NATO member nations can contribute something to the causeExercise A Directions: Listen to the news item and complete the summary.Exercise B Directions: Listen to the news again and answer the following questions1.He hopes America's NATO allies will stand with the United States if hedecides to take militaryaction against Iraq.2.No, the president says no action is likely in the near future.3.They expect the NATO summit to release a political statement backing the UNresolution.4.The NATO summit is held in Prague.No, it will not be the focus of the NATO summit.Bush-IraqPresident Bush says everyone knows the real power in Iraq lies with Saddam Hussein: "There is no democracy. This guy is a dictator and so we have to seewhat he says." The president says the Iraqi leader has a choice to make: disarm peacefully or be disarmed by force: "If Saddam Hussein does not comply to the detail of the resolution, we will lead a coalition to disarm him. It is over. We are through with negotiations. There is no more time. The man must disarm. He said he would disarm. He now must disarm." Mr. Bush spoke with reporters while touring the Washington D.C. police department, a tour designed to highlight his plan to create a cabinet level Department of Homeland Security. He left no doubt his patience regarding Iraq is wearing very thin*, stressing the United States will no longer tolerate any efforts by Saddam Hussein to circumvent* demands to disarm. Exercise BExercise ADirections: Listen to the news item and complete the summary.This news item is about the Bush administration's attitude towards Iraq. Directions: Listen to the news again and decide whether the following statements are true (T) or false (F).British Prime Minister Tony Blair delivered a radio address late Thursdayto the Iraqi people warning that Saddam Hussein must comply with UN demands or suffer the consequences.Prime Minister Blair said Saddam Hussein must cooperate with UN weapons inspectors, or be prepared to face military action. In an interview with Radio Monte Carlo's Arabic service Thursday, Mr. Blair said war could be avoided, if Iraq agreed to disarm."The situation is very clear. If Saddam Hussein agrees to disarm Iraq of all chemical, or biological or nuclear weapons programs and capability, then conflict would be avoided, and his duty is to cooperate fully with the inspectors to tell them exactly what material he has, to cooperate and comply with them in the eradication of that material."The prime minister said he wanted to speak directly to the Iraqi people to try to dispel* what he called myths that have arisen between Christians and Muslims. He said the dispute with Iraq is not about the West versus the East or about oil, but about weapons of mass destruction.Exercise ADirections: Listening to the news item and complete the summary.This news item is about British Prime Minister's stand on the Iraqi issue.Exercise BDirections: Listen to the news again and complete the following sentences.1.Prime Minister Blair warned that Saddam Hussein would suffer theconsequences unless he cooperated with the UN weapons inspectors. Saddam Hussein should cooperate fully with the inspectors to tell them exactly what material he has, and comply with them in the eradication of that material.2.On Thursday Tony Blair had an interview with Radio Monte Carlo's Arabicservice.3.According to the Prime Minister, the conflict can be avoided if SaddamHussein agrees to disarm Iraq of all chemical. or biological or nuclearweapons programs and capability.4.Mr. Blair said the dispute with Iraq is not about the West versus the East orabout oil, but about weapons of mass destruction.Section Four Supplementary ExercisesPart 1 Feature reportBlix’s Iraq InspectionThe chief UN arms inspector has been assigned the task of searching for weapons of mass destruction in Iraq. The Security Council gave Iraq this last opportunity to disarm or face serious consequences, a euphemism* for possible war. The United States says it will make sure Iraq disarms, one way or another.But Mr. Blix* emphasizes that his inspectors will not determine the courseof events in the region. He says they will visit suspected sites, conduct interviews with Iraqi scientists, ferret* out information and report back to the Security Council for its members to decide.As for US and British intelligence reports, which the Bush administration says proves that Iraq has banned weapons, Mr. Blix says he is not going into Iraq with pre-conceived ideas of what is there.The next test for Iraq will be December 8th, the deadline for Iraq to present a full accounting of its weapons programs. If Iraq presents, in effect, a blank sheet, Mr. Blix says, he would expect the United States to put its evidence on the table, so it can be verified.Iraq has persistently maintained it does not have the banned weapons. The latest such assertion came in a letter to the UN this week, in which Baghdad accepted the latest Security Council resolution setting out the parameters* for what experts say will be the most intrusive inspections in Iraq, so far.After the preliminary technical work starting Monday, Mr. Blix says, he expects the first wave of inspections to start November 27th. Two months later, he is required to report to the Security Council on Iraq's performance.Exercise ADirections: Listening to the news report and complete the summary.This news report is about Mr. Blix's weapons inspections in Iraq.Exercise BDirections: Listen to the news again and fill in the blanks with the missing words.Mr. Blix emphasizes that his inspectors will not determine the course of events in the region. He says they will visit suspectedsites, conduct interviews with Iraqi scientists, ferret out information and report back to the Security Council for its members to decide.The next test for Iraq will be December eighth, the deadline for Iraq to present a full accounting of its weapons programs. If Iraq presents, in effect, a blank sheet, Mr. Blix says, he would expect the United States to put its evidence on the table, so it can be verified.Iraq has persistently maintained it does not have the banned weapons. The latest such assertion came in a letter to the UN this week, in which Baghdad accepted the latest Security Council resolution setting out the parameters for what experts say will be the most intrusive inspections in Iraq, so far.Part 2 PassageRise and Fall of Egypt1.The Nile River was a kind friend but occasionally a hard taskmaster of the。
三月三活动方案小班
三月三活动方案小班一、活动主题。
“欢乐三月三,萌娃乐翻天”二、活动目标。
1. 让小班幼儿初步了解“三月三”的传统习俗,感受民族文化的魅力。
2. 通过有趣的活动,激发幼儿对民族文化的喜爱之情,增强民族自豪感。
3. 锻炼幼儿的动手能力、语言表达能力和社交能力。
三、活动时间。
[具体活动日期]四、活动地点。
小班教室及幼儿园户外操场(如果天气好的话)五、活动准备。
1. 教师准备。
收集关于“三月三”的图片、视频资料,制作成简单有趣的PPT。
准备好活动所需的材料,如彩色糯米饭的食材(糯米、紫甘蓝、黄栀子、枫叶等天然色素来源食材)、小绣球制作材料(彩色布块、棉花、小铃铛等)、小竹竿(用于跳竹竿舞)。
提前布置教室,营造“三月三”的节日氛围,张贴一些与“三月三”相关的图片,如壮族服饰、歌圩场景等。
2. 幼儿准备。
请家长提前给幼儿讲述一些关于“三月三”的简单故事,让幼儿有初步的认知。
六、活动流程。
# (一)活动导入(9:00 9:15)2. 播放欢快的壮族山歌音乐,教师随着音乐跳一小段简单的壮族舞蹈,邀请幼儿一起感受音乐的节奏,自由地摆动身体。
# (二)了解“三月三”(9:15 9:45)1. 教师播放PPT,用简单易懂、生动有趣的语言给幼儿介绍“三月三”的由来。
“小朋友们,在很久很久以前呀,有一个美丽的民族叫壮族。
每年的三月初三呢,就像我们过年一样热闹。
这一天呀,大家都会穿上漂亮的衣服,聚在一起唱歌、跳舞、吃好吃的。
”展示PPT上“三月三”歌圩的图片,解释说:“你们看,这些叔叔阿姨、哥哥姐姐们都在唱歌呢,这就叫做歌圩,大家用歌声来表达自己的快乐。
”2. 展示彩色糯米饭的图片,问幼儿:“小朋友们,你们看这个米饭是不是像彩虹一样漂亮呀?这可是壮族人民在三月三必吃的美食哦,它叫彩色糯米饭。
”简单介绍彩色糯米饭的制作过程,告诉幼儿这些漂亮的颜色都是从大自然的植物里变出来的,激发幼儿的兴趣。
# (三)制作彩色糯米饭(9:45 10:30)1. 将幼儿分成小组(每个小组3 4个小朋友),教师向幼儿展示制作彩色糯米饭的食材:“小朋友们,看,这是糯米,这是紫甘蓝,它可以把糯米变成紫色哦;这是黄栀子,能让糯米变成黄色呢;还有枫叶,可以做出黑色的糯米。
字谜-3——精选推荐
字谜-31、草原下⾯有颗⼼,⼈尔永远不分离,谆谆教诲不⽤说,元旦不是⼀⽉⼀,⼥⼈旁边⼦相随,思念粮⾷没有⽥,青草旁边藏颗⼼。
(谜底:愿你每⽇好⼼情)2、锦⾐⾦服兄⾝着,⼀个⼈有尔相伴,友⼈右⼿⼀竖左⼿⼀点,海边拾贝才快乐!友⼈右⼿⼀竖左⼿⼀点,⼤字踩在踏板上!(祝你发财,发达)3、天鹅飞去鸟归隐,⽩勺到⽼相伴陪,⽬光远视跟定你,⽥下有⼟⽣真情,⼝下有须很⽼诚,⽬中只有你⼀⼈,⼈尔结合幸福⼈。
(谜底:我的眼⾥只有你)4、兄弟⼿拿指⽰牌,指引⼈尔向前⾏,筷⼦不是⽤⽵制,灯光闪烁没有⽕,草莓头上不长草,灭了⽕后没有⽕,想吞⽶饭没有⼝。
(谜底:祝你快乐每⼀天)5、⽰旁站⽴兄长,尔等单⼈想傍,悔之⼼已离去,蚕⾍游离四⽅,⾐袂把⼼交互,掩去烁之⽕光,丽妍少⼥离去,志⼠远⾛他乡。
(谜底:祝你每天快乐开⼼)6、原本⼀⼼凝成爱,⼈尔结合好愉快,⼥⼦完美惹⼈爱,⼀撇⼀捺互⽀持,横竖都是⼀条⼼,⼀⽜⽴地⼜顶天,苹果去叶⽆纷扰,⼥⼦戴帽最美妙。
(谜底:愿你好⼈⼀⽣平安)7、天鹅⼀来鸟全飞,受⼈情意友坐底,尔旁⼀⼈两相伴,⽔头⼀点情深浓,砍去⽊头做成⾈,弯去⼸底⼜成器。
(迷底:我爱你永不变)。
8、青青草原有我⼼,⼼旁有尔不离分,⾟苦岁⽉有勇⼠,⼀⼝薄⽥⽰佳⾳,梅花未绽⽊正息,⽣⼈放⽜去耕耘,笑见百草化云纷。
(谜底:愿你幸福每⼀天)9、原来只因在⼼上,但见⼈来尔站旁,并因你两⽿不闻,如此忐忑上下⾛,⼤海因你⽽⼲涸,⼟地因你少⼗分,春蚕幼⾍⽆影踪。
(谜底:愿你开⼼每⼀天)更多精选专辑:指客⽹ () 栏⽬:猜字谜⼤全10、⽰字旁边⽴长兄,只见尔旁站⼀⼈,诀字⽆⼝却有⼼,烁字灭⽕真欢喜,⼤海⼲涸没有⽔,⼟地为你少⼗分,笑字草帽被摘⾛。
(谜底:祝你快乐每⼀天)11、⼀味蛮⼲少根筋,淅沥⾬落地也湿,⼗字路⼝选横⾏,⼀⼈孤单找个伴,⼥⼦埋头往西⾛,架⼦凭空没有⽊,抽⾛半边终遇⽔。
(谜底:⼆零⼀⼆要加油)12、坏屋⼟墙已被推,腰间亮剑退⽉回,貂⽪做⾐颜⾊美,为家伐⽊屋⾥堆,淮河⼜见⽔⼲涸,龙虾⾮⾍⼝⾥喂,到了⼈边反虺颓。
新视野大学英语3听说教程答案(清晰完整版)
Unit 6
Warming up 1."Get ready" 2.Climate changes are occuring more rapidly and natural disasters are becoming more severe. 3.Books on the subject of survival. Listening Short conversations 1.D 2.D 3.D 4.B 5.C 6.A 7.C 8.C 9.A 10.C Long conversation 1.A 2.C 3.B 4.B 5.D Passage 1.C 2.D 3.C 4.D 5.A Radio program 1.Islamabad 2.a tall Islamabad building 3.the Kashmirian Mountains 4.a heavily mititarized region 5.India
Unit 4
Warming up 1. Writer---Jack Kerouac 2. Artist---Jackson Pollock 3. Musician---Louis Armstrong 4. Symbol--- Statue of Liberty Listening Short conversations 1.B 2.B 3.C 4.D 5.A 6.B 7.D 8.C 9.D 10.A Long conversation 1.C 2.D 3.B 4.B 5.A Passage 1.B 2.A 3.D 4.D 5.B Radio program 1.for decades 2.healthy and aactive lifestyle 3.meet consumer demands
大学思辨英语教程 精读3课件Unit 3
Lead in
Text A offers an enlightening analysis of non-verbal communication across different cultures. The authors, Edward T. Hall and Mildred R. Hall, show us that cultural barriers could be overcome by increasing our awareness of cultural differences and by learning about the different ways in which we behave in different societies.
While culture is learned through practice and socialization, Text B provides a counter example to demonstrate the result of non-socialization. As you read the text, you can consider the importance of socialization for you to survive and develop your potential in a particular society.
Critical Thinking
Reading Skills
Learning Objectives
• Reading Skills
• Identify the structure of the text • Identify topic sentences • Use context to understand a new word
新标准大学英语综合教程3 unit3 课文翻译
新标准大学英语综合教程3 unit3 课文翻译Unit3Active reading 1我们是怎样听音乐的我们都按照各自不同的能力来听音乐。
但为了便于分析,如果把听的整个过程分成几个组成部分,那么这个过程会更清晰一些。
从某种意义上来说,我们听音乐有三个不同的层次。
由于缺乏更好的术语,我们姑且把它们命名为:(1)感官层次;(2)表现层次;(3)纯音乐层次。
把听的过程机械地分割为以上三个假想的层次,唯一的好处是让我们更清楚地了解自己是怎样听音乐的。
听音乐最简单的方式是为了去获取乐声带来的纯粹的愉悦感,这是音乐的感官层次。
在这个层次上,我们只是听音乐,不做任何思考。
我们打开收音机,一边做着其他的事情,一边心不在焉地沉浸在音乐中。
乐声本身的魅力带我们进入一种无需思考的美妙心境。
令人意外的是,许多自认为是合格的音乐爱好者在听音乐时过多地使用了这一层次。
他们去听音乐会是为了忘却自我。
他们把音乐当成一种慰藉,一种逃避,由此他们进入了一个可以忘却日常生活的理想世界。
当然,他们也没有在思考音乐。
音乐允许他们离开现实,到另一个地方去做梦,因为音乐而做梦,做有关音乐的梦,却从没有真正欣赏过音乐。
的确,乐声的魅力是一种强大而原始的力量,但是你不该让它占据你过多的兴趣空间。
感官层次是音乐的一个重要层次,非常重要,但并不是音乐的全部。
音乐存在的第二个层次就是我所说的表现层次。
一提到这个问题,我们马上就进入到一个颇具争议的领域。
作曲家总是设法避开有关音乐表现方面的讨论。
斯特拉温斯基不是曾经声称他的音乐是一个“物体”,是一件有自我生命的“东西”,除了纯音乐性的存在之外没有任何别的含意吗?斯特拉温斯基这种不妥协的态度可能源于这样的一个事实:有那么多的人尝试着从众多的音乐作品中读出完全不同的含意。
确实,要准确地说出一部音乐作品的含意已经很难了,要肯定并确定地说出来,还要使每个人对你的解释都感到满意,是难上加难。
但我们不该因此走到另一个极端,不能去剥夺音乐“表现”的权利。
Unit3 Reading3
"Gabby, You're Sooo Skinny""加贝,你太瘦了"I am a straight-A student.我是优等生。
I am very involved in school activities and considered a "very together”teenager.我积极参与学校活动,被认为是一个“非常合群”的青少年。
Or at least, I was It all started innocently enough.或者至少,我是这一切都开始得足够天真。
I weighed about 125 pounds. 我重约125磅。
I was not fat, but felt I could stand to lose a few pounds. 我并不胖,但我觉得我可以减几磅。
A friend of mine had gone on a health kick and was getting great results from it -she was losing weight, she felt better and her friends were telling her how great she looked I wanted to feel that way, too.我的一个朋友参加了一个健康计划,并取得了很好的效果——她的体重减轻了,她感觉好多了,她的朋友们告诉她,她看起来很好——我也想有那样的感觉。
I began exercising and eating healthy snacks instead of the usual Coke and-chips marathon watching the boob tube.我开始锻炼,吃健康的零食,而不是像往常那样马拉松式地看电视。
Within a couple of weeks I had lost weight, I was feeling good, I cared more about what I wore and started feeling attractive in a way I had not experienced before.几周后,我的体重减轻了,我感觉很好,我更关心自己的穿着,我开始以一种从未有过的方式感到自己很有吸引力。
3在生活中可以表示什么
3在生活中可以表示什么
在生活中,数字3可以表示许多不同的事物和概念。
从数学到文化,从宗教到
哲学,数字3都扮演着重要的角色。
让我们来看看在生活中,数字3可以表示什么。
首先,数字3在数学中代表着一个重要的概念,三角形。
三角形是几何学中的
基本形状之一,它由三条边和三个角组成。
三角形在建筑、设计和工程中都有着重要的应用,因此数字3在数学中具有重要的意义。
其次,数字3在文化和宗教中也有着特殊的含义。
在基督教中,三位一体是一
个重要的概念,代表着上帝的三位形态,父、子、圣灵。
在许多其他宗教和文化中,数字3也代表着神圣的力量和完美的平衡。
最后,数字3在日常生活中也有着特殊的意义。
许多人认为“第三次正是魅力
所在”,这意味着第三次尝试通常会带来成功。
此外,人们常常将事物分为三个部分,比如早、中、晚;过去、现在、未来等等。
总的来说,数字3在生活中有着丰富的含义和应用。
无论是在数学、文化、宗
教还是日常生活中,数字3都扮演着重要的角色,代表着力量、平衡和完美。
让我们珍惜数字3,体会它在生活中的深刻意义。
3 三级配电
第三节供配电系统与配电装置一、三级配电系统施工现场用电工程的基本供配电系统应当按三级设置,即采用三级配电。
(一)三级配电系统基本结构三级配电是指施工现场从电源进线开始至用电设备之间,应经过三级配电装置配送电力,即由总配电箱(一级箱)或配电室的配电柜开始,依次经过分配电箱(二级箱),开关箱(三级箱)到用电设备。
这种分三个层次逐级配送电力的系统就称为三级配电系统。
配电系统采用放射式和树干式,它的基本结构如以下框图。
(二)系统的设置原则三级配电系统应遵守四项基本原则:即分级分路原则,动照分设原则,压缩配电间距原则,环境安全原则。
1、分级分路(1) 从一级总配电箱(配电柜)向二级分配电箱配电可以分路,即一个总配电箱(配电柜)可以分若干分路向若干分配电箱配电;(2) 从二级分配电箱向三级开关箱配电同样可以分路,即一个分配电箱可以分若干支路向若干开关箱配电。
(3) 从三级开关箱向用电设备配电实行“一机一闸”制,不存在分路问题。
即每一开关箱只能连接控制一台与其相关的用电设备(含插座)。
按照分级分路原则的要求,在三级配电系统中,任何用电设备都不得越级配电,总配电箱和分配电箱不得挂接其它任何设备,否则,三级配电系统的结构形式和分级分路原则将被破坏。
2、动照分设动力配电箱与照明分配电箱宜分别设置。
当动力和照明合并设置于同一配电箱时,动力和照明应分路配电,动力和照明开关箱必须分别设置,不存在共箱分路设置问题。
3、压缩配电间距压缩配电间距原则是指各配电箱、开关箱之间的距离应尽量缩短。
总配电箱应设在靠近电源的区域,分配电箱应设在用电设备或负荷相对集中的区域,分配电箱与开关箱的距离不得超过30m,开关箱与其控制的固定式用电设备的水平距离不宜超过3m。
4、环境安全环境安全是指配电系统对其设置和运行环境的安全要求,包括三种环境要求:使用环境、维修环境和防护环境。
要求如下:(1) 使用、维修环境:满足压缩配电间距原则。
配电箱、开关箱周围应有足够二人同时工作的空间和通道,不得堆放任何妨碍操作、维修的物品,不得有灌木、杂草。
中国古代数字3的含义
中国古代数字3的含义
中国古代数字3的含义,可以用中文写成:"三"代表了很多重要
意义。
首先,它象征着天、地、人的统一,体现了宇宙的完整性和和谐。
其次,"三"也代表了生命的循环,包括过去、现在和未来的连续性。
此外,"三"也代表了三才(天、地、人)和三光(日、月、星),表达了自然的规律性和秩序。
古人还将"三"作为吉祥和幸运的象征,
认为它代表着吉祥、安宁和福气。
在文化传统中,"三"也被广泛应用
于许多方面,例如三才图、三角梅等。
总的来说,中国古代数字3具
有丰富的内涵和文化意义。
成本管理作业3参考答案
第3次任务试卷总分:100 测试时间:--一、单项选择题(共 23 道试题,共 23 分。
)1. 采用定额法计算产品成本时,生产工资费用定额的计算公式是(D)。
A. 产品实际工时×生产工资实际单价B. 产品实际工时×生产工资计划单价C. 产品生产工时定额×生产工资实际单价D. 产品生产工时定额×生产工资计划单价2. 由于修改旧定额而产生的新旧定额之间的差额称为(C)。
A. 定额差异B. 材料成本差异C. 定额变动差异D. 脱离定额的差异3. 采用定额法计算产品成本时,若差异额较大而且各月在产品数量变动也较大,差异额在完工产品和月末在产品之间进行分配的方法一般是采用(B)。
A. 定额差异的比例B. 定额成本的比例C. 脱离定额差异的比例D. 材料成本差异的比例4.定额法下的定额变动差异是指由于修订消耗定额或生产耗费的计划价格而产生的(B)。
A. 计划价格与实际价格的差额B. 新旧定额的差额C. 实际价格与计划价格的差额D. 月初定额与月末定额的差额5. 采用定额法计算产品成本时,对于定额变动差异若是定额降低,在月末计算产品成本时,还应( C )。
A. 从当月的产品成本当中扣除B. 加到当月的产品成本当中C. 对当月产品成本没有影响D. 应在月初产品成本当中进行调整,月末在产品成本不进行调整6. 定额法下的产品成本计算单中,在消耗定额降低时,月初在产品的定额成本调整和定额变动差异数,( D )。
A. 都是负数B. 都是正数C. 前者是正数,后者是负数D. 前者是负数,后者是正数7. 定额法的特点是( B )。
A. 对产品进行事前控制B. 对成本差异进行日常核算、分析和控制C. 进行成本的定期分析和考核D.上列三点都具备8. 定额成本与计划成本( D )。
A. 完全是一回事B. 毫无联系C. 可以互相代替D. 既有相同之处,也有不同之处,两者不能互相替代。
9. 在制造费用分为变动制造费用和固定制造费用的情况下,生产能力利用差异的计算公式是( B )。
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第三章 平面机构的静力分析
3-1 在用丝锥进行攻丝加工时,必须用两手握住扳手,而且用力要相等。
为什么不允许用一只手扳动扳手?
3-2 运用力的平移定理解释其他日常生活现象如单浆划船,船的运动;在乒乓球、足球边上作用一个力,乒乓球、足球的运动。
3-3 重量为G 的站在船的正中时,使船平移下沉一距离;若人站在船舷时,船不但下沉一距离,还倾斜一定角度。
为什么?
3-4 有一小车,用电机驱动车轮,在轨道上行驶,问小车在给定时间内达到的车速(启动速度)是否要多大就能达到多大?为什么?欲提高启动速度有什么办法?
3-5 为什么车胎打足了气之后,人骑起来感到省力?
F 1
3-6 如题3-6图所示,固定环受3条绳的作用,已知3个力的大小依次为F 1=1kN 、F 2=2kN 和F 3=1.5kN ,试求该力系的合力。
F 2
F 3题3-6图
3-7 力F =150N ,按题图3-7(a )(b )(c )三种情况作用在扳手的A 端。
试求此三种情况下力对O 点之矩。
(c ) (b ) (a ) 题3-7图
3-8 如题3-8图所示为冲天炉加料斗,该料斗由钢丝绳牵引沿轨道上升,料斗连同物料共重G ,重心在C 点,不计轨道与车轮之间的摩擦、试画出料斗的受力图。
3-9 如题3-9图所示,用力F 拉动碾子压平路面时,碾子受到固定石块A 的阻碍。
试画出碾子的受力图。
3-10 如题3-10图所示为一夹紧装置。
试画出压板和工件的受力图。
(a )方案一
(b )方案二 (c )方案三
题3-8图 题3-9图 题3-10图 3-11 如题3-11图所示为一螺栓组连接的三种方案?已知L =300mm 、a=60 mm .试求该螺栓组三个方案中受力最大螺栓的剪力各为多少?并说明哪种方案较好?
题3-11图
3-12 如题3-12图所示,液压式汽车起重机全部固定部分所受重力为F G1=60 000N,旋转部分所受重力为F G2=20 000 N,a=1.4m,b=0.4m,l l=1.85m,l2=1.4m。
试求:当R=3m,起吊重量F G=50 000 N时,支撑A、B所受地面的支承反力。
题3-12图
3-13 如题3-13图所示为机床夹具中的斜楔增力机构,楔角α=10°,推进斜楔的作用力P =300N,摩擦不计,试求立柱对工件的夹紧力Q的值。
工件
题3-13图
3-14 如题3-14图所示是机械操作车间的一个液压夹紧机构。
若作用在活塞A上的力的大小为F=1kN,α=10°,不计各构件的重量与接触处的摩擦,试求工件H所受的压力。
题3-14图
3-15 发动机的凸轮机构如题3-15图所示。
当凸轮转动时,推动杠杆AOB 来控制阀门C 的启闭,设压下阀门将要对它作用F =400N 的力,α=30°,β=20°,求凸轮对滚子A 的压力P 及支座O 的约束反力。
β
题3-15图 题3-16图
3-16 飞机起落架尺寸如题3-16图所示,A 、B 、C 为铰链,杆OA 垂直于AB 。
当飞机匀速直线滑行时,地面作用于轮上的铅垂正压力F P =30kN ,不计摩擦和各杆的重力,试求A 、B 处的约束反力。
3-17 盘铣刀加工直齿圆柱齿轮时,齿轮装在分度头上,如题3-17图所示,切削力Pa =2kN , Pr=0.5kN ,主轴自重不计。
试求A 、B 处轴承的约束反力。
题3-17图
3-18 如题3-18图所示为一铰接式载货汽车,汽车的重量为30kN ,重心在G l 点。
拖车的重量力15kN ,重心在G 2点。
拖车上的装载物重量为80kN ,重心在G 3点。
拖车通过铰链D 连接在汽车上。
当汽车匀速行驶时,求地面对A 、B 、C 三处车轮的约束力。
题3-18图
3-19 带式运输机的传送带与砂石之间的静摩擦系数f=0.5,试问传送带的最大倾角α可为多少?
题3-19图
3-20 机床上的滑动件支承在V型导轨上,如题3-20图所示,载荷q(N/m)沿长度均匀分布。
已切静摩擦系数为f,求推力P应为多大才能使滑动件运动。
题3-20图
3-21 起重设备常用双块式电磁制动器制动,如题3-21图所示。
制动轮直径d=50cm,受一主动力偶矩M=1kN·m作用。
若制动轮与制动块之间的摩擦系数f=0.25,问欲使制动轮
停止,所需加于制动块上的压力Q至少应多大?
题3-21图
3-22 如题3-22图所示,已知两标准直齿圆柱齿轮的半径r C=100mm,r D=50mm,其上受力有:圆周力F t1=3.58kN,径向力F r1=1.3kN。
AC=CD=DB=100mm。
求D轮的圆周力F r2,F t2及A、B 两轴承的反力。
题3-22图。