传感器13章课后习题答案.doc
1. 传感器:能够感受规定的被测量并按照一定规律转换成可用输出信号的器件或装置。2. 按功能分:力敏,热敏,光,湿磁敏传感器;按工作原理:应变式,热变式,压电式。3. 静态特性:a线性度; b灵敏度;c重复性;d迟滞;e重复性,分辨力,测量范围和量程;4. 动态特性:传感器对随时间变化的输入量的响应特性。研究动态特性从时域和频域采用瞬态响应法和频率相应法来分析。5. 电阻应变效应:一根金属导线在其拉长时电阻增大,在受压缩短时电阻减小。6. 直流电桥:联接成环的四个电阻组成。减小或消除非线性误差的方法:提高桥臂比采用差动电桥a,半桥差动,;b,全桥差动,。7. 热输出特性:温度变化,总电阻相对变化;虚假应变为8. 热补偿方法:a,单丝自补偿应变片;b,双丝组合式自补偿应变片;c,电路补偿法9. 电容式传感器:变间距型:极板1固定不动,极板2喂可动电极即动片,当动片随被测量变化而移动时,两级板间距随之发生变化,从而使电容量发生变化。变面积型电容传感器:测量范围大,可测量较大的线位移或角位移变介电常数型电容传感器10.非线性误差灵敏度差动式变间距型传感器单一型传感器11. 调频测量电路:把电容式传感器的电容作为振荡器谐振回路的一部分,与一个电感元件配合成一个振荡器谐振电路。电容量发生变化振荡频率产生相应变化,通过鉴频电路将频率转化为振幅变化,经放大器放大后进行显示,此法叫调频法。12. 电容式传感器边缘效应:当极板厚度与极板距离可比时,两级板边缘处的电力线出现分布不均匀的现象。措施:a,适当减小极间距,使电极直径或边长与间距比增大;b,电极做薄,使之与极间距相比减小;c,结构上增设等位环。13. 二极管双T型电路:e 是高频电源 , 它提供幅值为 Ui 的对称方波 , VD1 、 VD2 为特性完全相同的两个二极管 , R1 = R2 = R, C1 、 C2 为传感器的两个差动电容。当传感器没有输入时 , C1 = C2 。电路工作原理如下 : 当 e 为正半周时 , 二极管 VD1 导通、 VD2 截止 , 于是电容 C1 充电 ; 在随后负半周出现时 , 电容 C1 上的电荷通过电阻 R1#, 负载电阻 RL 放电 , 流过 RL 的电流为 I1 。在负半周内 , VD2 导通、 VD1 截止 , 则电容 C2 充电 ; 在随后出现正半周时 , C2 通过电阻 R2, 负载电阻 RL 放电 , 流过 RL 的电流为 I2 。 根据上面所给的条件 , 则电流 I1 =I2, 且方向相反 , 在一个周期内流过 RL 的平均电流为零。 差动脉宽调制电路:以下是大学体验英语综合教程2(第三版)课后翻译答案Unit11. 任何年满18岁的人都有资格投票。(be eligible to, vote)Answer:Anyone over the age of 18 is eligible to vote. 2. 每学期开学前,这些奖学金的申请表格就会由学校发给每一个学生。(apply for, scholarship)Answer:A form to apply for these scholarships is sent by the university to every student before the start of every semester. 3. 遵照医生的建议,我决定戒烟。(on the advice of)Answer:On the advice of my doctor, I decided to give up smoking. 4. 公园位于县城的正中央。(be located in)Answer:The park is located right in the center of town. 5. 这所大学提供了我们所需的所有材料和设备。(facilities) Answer:The university provides all the materials and facilities we desire.1. 他们花了多年的时间寻找内心的平静,但是收效甚微。(search for)Answer:They spent many years searching for peace of mind, but with little success. 2. 这种新药的成功研制已经使许多疾病的治疗发生了根本性的变革。(revolutionize)Answer:The successful development of the new drug has revolutionized the treatment of many diseases. 3. 由于这个国家的经济不景气,这家公司濒于破产。(on the edge of)Answer:The company is on the edge of bankruptcy due to the economic depression in the country. 4. 大学毕业后他成为了一名护士。他认为护士这一职业可能很有发展前途。(rewarding)Answer:He became a nurse after college. He thought nursing could be a very rewarding career. 5. 他像往常一样在文件上签了名。(just as) Answer:He signed his name on the paper just as he has always done it.Unit21. 警察们正忙着填写关于这场事故的各种表格。(fill out)Answer:The policemen are busy fi lling out forms about the accident. 2. 我想在还车之前把油箱加满。(fill up, fuel tank)Answer:I want to fi ll up the fuel tank before returning the car. 3. 如果你要投诉,最好遵循正确的程序。(follow the procedure)Answer:If you want to make a complaint, youd better follow the correct procedure. 4. 要不是约翰帮忙,我们绝不会这么快就完成实验。(without)Answer:We couldnt have fi nished the experiment so soon without Johns help. 5. 暴风雨之后,岸边的人们焦急地搜索湖面以期发现小船的踪迹。(scan for)Answer:After the storm, the people on the shore anxiously scanned the lake for any sign of the boat.1. 这个国家不大,但是在国际事务中它却发挥着重要作用。(play a role)Answer:This country is not big, but it plays an important role in international affairs. 2. 正是在我叔叔的帮助下,我得以克服困难,按时完成了任务。(it is . that)Answer:It was with the help of my uncle that I overcame the difficulty and completed the assignment in time. 3. 毕业时他决定留在北京,而他最好的朋友却选择了去西藏。(while)Answer:While he decided to stay in Beijing upon graduation, his best friend chose to go to Tibet. 4. 在这次校园英语演讲比赛中,我们班的玛丽获得了第三名。(come in)Answer:In this Campus English Speaking Contest, Mary from our class came in third. 5. 你应该知道学习弹钢琴需要有时间,有金钱,还要有毅力。(as well as) Answer:You should know that it takes time, money as well as perseverance to learn to play the piano.Unit31. 我发现量入为出地过日子越来越难了。(increasingly) Answer:I find it increasingly difficult to live within my income.2. 现代政治家们都试图以电视讲话来影响普通百姓。(reach out) Answer:Modern politicians try to reach out to ordinary people in their TV speeches.3. 应该帮助学生对人生采取积极的态度。(adopt) Answer:Pupils should be helped to adopt a positive attitude to life.4. 希望全班同学参加这些讨论。(participate in) Answer:Everyone in the class is expected to participate in these discussions.5. 如果你犯了罪就必须受到惩罚。(crime) Answer:If you commit a crime you must expect to be punished.1.儿子的死让老妇人变得麻木痴呆了。(numb)Answer:The old woman was numbed by her sons death.2.身处所有这些烦恼之中,他依然能保持乐观。(in the midst)Answer:In the midst of all troubles, he managed to remain cheerful.3. 虽有困难,他们还是设法坚持试验下去。(carry on) Answer:They managed to carry on their experiments in spite of the difficulties.4.我们必须淘汰不合格的申请人。(weed out) Answer:We have to weed out unqualified applicants.5. 医生要他减少抽烟。(cut down on) Answer:The doctor told him to cut down on smoking.Unit41.她在公共汽车站一直等到末班车进站。(come in)Answer:She waited at the bus stop until the last bus came in.2.如果我们能帮得上忙,尽管和我们联系。(contact)Answer:If there is any way we can be of assistance, please do not hesitate to contact us.3 .他需要多少船务人员才能使他的游艇航行?(crew, yacht)Answer:How many crew does he need to sail his yacht?4 .虽然她的新书没有上一本好,但是我还是喜欢它。(not quite as)Answer:I enjoyed her new book though its not quite as good as her last one.5 .我从未遇到过如此善良的人。(never before)Answer:Never before have I met such a kind person.1.公共汽车放慢速度并停下,让那位乘客上车。(slow down)Answer:The bus slowed down and stopped to allow the passenger to get on board.2.许多车子都驶过去了,可是没有一辆愿意让我们搭便车。(roll by)Answer:Many vehicles rolled by, but no one offered us a ride.3 .请勿践踏草地。(get off)Answer:Please get off the grass.4.他按妻子的吩咐,一下班就去了市场。(make ones way)Answer:He made his way to the marketplace right after work, as his wife had asked him to do.5 .值得庆幸的是,史蒂夫 (Steve) 从自行车上摔下来时没有摔断骨头。(luckily)Answer:Luckily, Steve didnt break any bones when he fell off his bike.Unit51. 我们得把感情放在一边,从专业的角度来对待这件事。(from a professional standpoint)Answer:We have to put aside our emotions and take it from a professional standpoint.2. 这部戏非常精彩,我很快就沉浸于激动人心的剧情之中。(lose oneself in)Answer:The play was so wonderful that I soon lost myself in the excitement of it.3 .她没有什么爱好除非你把看电视也算是一种爱好。(unless)Answer:She hasnt got any hobbies unless you call watching TV a hobby.4. 他说他是直接从市长本人那里得到这个信息的。(first-hand)Answer:He said that he had got the information first-hand from the Mayor himself.5 .既然你不能回答这个问题,我们最好问问别人。(since)Answer:Since you cant answer the question, perhaps wed better ask someone else.1. 由于公共汽车司机突然刹车,旅客们都不由自主地向前摔倒。(brake, pitch forward)Answer:All the passengers pitched forward because the bus driver braked sharply.2. 这个协议将冲破对自由贸易设置的障碍。(break through, obstacle)Answer:This agreement will break through the obstacles to free trade.3 .我刚放下叫出租车的电话,车就来了。(soon after)Answer:The taxi arrived soon after I rang for it.4. 在过去,不管我什么时候到家,我父母总会等我。(no matter)Answer:My parents always waited up for me no matter what time I got home.5 .由于没有一方愿意让步,两个公司之间的对话完全破裂了。(break down)Answer:Talks between the two companies completely broke down, because neither of them wanted to give in.Unit61. 那件工作很难做,不过我想试试看。(have a shot) Answer:Its a difficult job, but Id like to have a shot.2. 这是一本关于商务实践而非理论的书。(as opposed to)Answer:This is a book about business practice as opposed to theory.3. 社会活动从未耽误她的学习。(in the way) Answer:Social activities never get in the way of her studies.4. 直到1911年人们才发现第一种维生素。(It is not until . that) Answer:It was not until 1911 that the first of the vitamins was identified.5. 尽管年事已高,爷爷每天还帮忙做家务。(despite)Answer:Despite advanced years, Grandpa helps do housework every day.1. 我们的婚姻很幸福,但我们也曾经历过许多坎坷。(ups and downs)Answer:Our marriage is happy but weve had many ups and downs. 2. 许多外语教师常常在课堂上自顾自地讲得太多。(be inclined to)Answer:Many teachers of foreign languages are inclined to talk too much themselves in class. 3. 那位著名演员每天早晨锻炼一小时以保持健康。(work out)Answer:The famous actor keeps fit by working out for an hour every morning. 4. 与他促膝长谈之后,她的怀疑消失了。(melt away)Answer:After a long heart-to-heart talk with him, her suspicion melted away. 5. 目前我们没有职位空缺,但我们肯定会记住您的申请。(keep in mind)Answer:We have no vacancies now, but well certainly keep your application in mind.Unit71. 他并不后悔说过的话,只是觉得他完全可以不用这种方式表达。(could have done)Answer:He did not regret what he had said but felt that he could have expressed it differently.2. 我们最好等到12月14日。那时大卫已考完试,就能和我们一起去度假了。(will have done)Answer:Wed better wait till 14 December. David will have had his exam by then, so hell be able to go on holiday with us.3. 他正在做一个新项目,年底前必须完成。(work on)Answer:Hes working on a new project which has to be finished by the end of the year.4. 他们让我们使用他们的实验室,作为回报,我们则让他们分享研究成果。(in return)Answer:They are letting us use their lab, and in return, we are sharing with them the results of our research.5. 诸如打电话、听电话一类的事情占用了这位秘书的大部分时间。(take up)Answer:Such things as making and answering telephone calls take up most of the secretarys time.1. 他们把房子卖了后就到加拿大和女儿住在一起。(go off) Answer:They sold their house and went off to live in Canada with their daughter.2. 你下星期这个时候会在干什么?还是像平常一样干活。(will be doing) Answer:What will you be doing this time next week?Ill be working as usual.3. 他既聪明又勤奋,不久就接管了杂志的编辑工作。(editing; before long)Answer:He was intelligent and hard-working and before long he took over the editing of the magazine.4. 你话还没说完别人就挂断电话,难道你不恼火吗?(hang up)Answer:Dont you hate it when someone hangs up on you before you finish speaking?5. 让他们感到惊恐的是,他们的房顶着火了。(to ones horror)Answer:To their horror, the roof of their house caught fire.14.