相关试题
【判断题】
一次追加减压量超过初次减压量,会使列车制动力急剧增加,不利于平稳操纵。
【判断题】
电空制动机的最大优点是全列车能迅速实现制动和缓解作用,且列车前、后动作一致性好,适用于高速旅客列车和长大货物列车。
【判断题】
在我国铁路车辆上均装有手动制动机,用于空气制动机故障时以及调车作业、坡道停留时的制动。
【判断题】
制动盘装在车轴上的叫轴盘式盘形制动基础制动装置。
【判断题】
在坡道上停留时间较长时,为防止空气制动机因制动缸漏泄发生自然缓解,还应拧紧手制动机。
【判断题】
折角塞门用来开通或遮断制动主管与制动软管之间的空气通路。
【判断题】
总风管既是一根压力空气输送管,也是一根传递列车制动、保压和缓解指令的控制管。
【判断题】
截断塞门关闭的车辆(简称“关门车”)无空气制动作用。编入列车的关门车数以及关门车在列车中所处位置限制须符合《技规》规定。
【判断题】
所谓灵敏度就是制动机的感度,它是评价车辆制动机性能的主要指标之一。
【判断题】
空气波是属于一种振动波,具有波的性质。空气波的传播速度称为空气波速。
【判断题】
制动作用或缓解作用沿列车长度方向的传播速度分别称为“制动波速”或“缓解波速”。
【判断题】
制动波速(或缓解波速)是用来评价列车的制动(或缓解)灵敏度。
【判断题】
在无线灯显调车时,自收到紧急停车信号后,如速度不为零则常用制动。
【判断题】
在无线灯显调车时,信号与口令不符时应立即停车。
【判断题】
LKJ-2000运行监控记录装置,参数设定操作,在机车运行或停车时均可操作。
【判断题】
LKJ-2000型监控记录装置,对制动机实验操作,装置均一一记录。
【判断题】
LKJ-2000运行监控记录装置只有在降级状态下,[开车]键才能起作用。
【判断题】
LKJ-2000运行监控记录装置机车越过信号机时距离显示仍有余值,经过一段距离后才显示O,这种零显示出现在信号位置之后的过机误差称为滞后误差。
【判断题】
监控装置启动停车模式时,不允许使用“向前”键进行车位调整。
【判断题】
LKJ-2000运行监控装置退出调车状态时,在停车状态下按压[调车]键就退出调车状态。
【判断题】
LKJ-2000运行监控记录装置,当机车运行中发生“常用制动”指令后乘务员一次按压[缓解]键完成缓解操作。
【判断题】
LKJ-2000运行监控记录装置,在屏幕显示器上只能利用IC卡进行文件转储操作。
【填空题】
1.一般电阻的阻值与___成正比,与导体截面积成反比。
【填空题】
2.电阻串联电路中总电流与通过各用电器的___相等。
【填空题】
3.当把三极管接入电路中时,___电流的微小变化,将引起集电极电流及发射极电流较大的变化。
【填空题】
6.机车电器按其执行机构的不同可分为有触点电器和___。
【填空题】
7.直流串励发电机的励磁绕组与电枢绕组串联,用___电流励磁。
【填空题】
8.变压器是根据___原理制成的一种能把交流电从一个电压值转换为另一个不同电压值的静止电器。
【填空题】
9.三相交流电各相绕组的首端与尾端之间的电压称为___。
【填空题】
10.过电压会使直流电机绕组造成___等事故。
【填空题】
11.由4个桥臂和___所组成的电路叫电桥电路。
【填空题】
12.三相交流电机的定子绕组联接方法有___和三角形接法两种。
【填空题】
13.直流电机既可作为发电机工作,也可作为电动机工作。这称之为直流电机的___。
【填空题】
14.机车牵引电机在电阻制动时作为___运行。
【填空题】
15.对于交-直流传动的电力机车,由于整流器输出电压是一个脉动电压,在整流电路中必然产生___。
推荐试题
【单选题】
The author thinks that people are _________. ___
A. satisfied with their appearance
B. concerned about appearance in old age
C. far from neglecting what is in fashion
D. reluctant to follow the trends in fashion
【单选题】
Fashion magazines and TV advertisements seem to link fashion to _________. ___
A. confidence in life
B. personal dress
C. individual hair style
D. personal future
【单选题】
Causes of fashions are _________. ___
A. uniform
B. varied
C. unknown
D. inexplicable
【单选题】
Present-day society is much freer and easier because it emphasizes _________. ___
A. uniformity
B. formality
C. informality
D. individuality
【单选题】
Which is the main idea of the last paragraph? ______________ ___
A. Care about appearance in formal situations.
B. Fashion in formal and informal situations.
C. Ignoring appearance in informal situations.
D. Ignoring appearance in all situations.
【单选题】
Permissive parents would ________. ___
A. let their children read any books they like to
B. not let their children see any films they like to
C. not let their children read any books without first checking their contents
D. let their children see the films with their first checking
【单选题】
The fact that parents check the contents of the book or the film for their children to read or see shows __________. ___
A. the necessity of censorship
B. that many books and films are bad
C. that children need their parents to help them understand more
D. that the parents are permissive
【单选题】
Which of the following statements is NOT true?____________ ___
A. Some adults can’t tell right from wrong.
B. Censorship is compared to the law because both of them perform good service to society as a whole.
C. Censors pay attention only to genuine works of art.
D. Censorship is necessary because many books, plays and films are far from being “works of art”.
【单选题】
What does the word “corrupt” in Para.4 mean?__________ ___
A. Make morally bad.
B. Hurt.
C. Injure.
D. Damage.
【单选题】
What would be the best title of this passage?_____________ ___
A. Permissive Parents and Responsible Parents.
B. Censorship and the Law.
C. Censors Value Artistic Merits .
D. Censorship Performs Good Service to Society.
【单选题】
Lie detectors are widely used in the United States because _____________. ___
A. they can help detect people’s emotional stress
B. they can help detect people's physiological changes
C. they can help find out whether a person is telling the truth or not
D. they can measure the subject’s electrical resistance
【单选题】
According to the passage, we know that Britain______________. ___
A. will adopt lie detectors widely
B. will adopt lie detectors on a smaller scale
C. adopt lie detectors
D. has not decided whether to adopt lie detectors or not
【单选题】
The tests themselves are by no means free from error..." (Line 1-2.Para.3) means ____________. ___
A. the tests definitely have no error
B. the tests sometimes make mistakes
C. the polygraphers do not make mistakes
D. the polygraphers can avoid error by using some techniques
【单选题】
Which of the following is true? ________________ ___
A. The tests are conducted by qualified polygraphers.
B. Innocent people may blush or stammer when questioned.
C. Guilty people can definitely be found out by answer questions
D. Guilty people may escape by refusing to answer questions.
【单选题】
What troubles lie detector researchers most is that _______________. ___
A. innocent people are convicted crimes
B. innocent people will learn to tell lies
C. lie detectors may cause industrial unrests
D. lie detectors are sometimes not dependable
【单选题】
In the passage the author's attitude towards "mixed-ability teaching" is _______. ___
A. critical
B. questioning
C. approving
D. objective
【单选题】
By "held back" (Line 1) the author means _____. ___
A. made to remain in the same classes
B. forced to study in the lower classes
C. drawn to their studies
D. prevented from advancing
【单选题】
The author argues that a teacher's chief concern should be the development of the student's _________. ___
A. personal qualities and social skills
B. total personality
C. learning ability and communicative skills
D. intellectual ability
【单选题】
Which of the following is NOT MENTIONED in the third paragraph? __________ ___
A. Group work gives pupils the opportunity to learn to work together with others.
B. Pupils also learn to develop their reasoning abilities.
C. Group work provides pupils with the opportunity to learn to be capable organizers.
D. Pupils also learn how to participate in teaching activities.
【单选题】
The author's purpose in writing this passage is to ______. ___
A. argue for teaching bright and not-so-bright pupils in the same class
B. recommend pair work and group work for classroom activities
C. offer advice on the proper use of the library
D. emphasize the importance of appropriate formal classroom teaching
【单选题】
According to the author, the deaths among youth are mainly caused by _____. ___
A. traffic accidents
B. smoking-related diseases
C. murder
D. all of these
【单选题】
Every day there are over_____high school students who will become regular smoker. ___
A. 75
B. 23
C. 30
D. 3000
【单选题】
By "dropout" the author means______. ___
A. students who failed the examination
B. students who left school
C. students who lost their way
D. students who were driven out of school
【单选题】
The reason for declining adolescent smoking is that ________. ___
A. NCI has taken effective measures
B. smoking is prevented among high school seniors
C. there are many smokers who have died of cancer
D. not stated
【单选题】
What is implied but not stated by the author is that ________. ___
A. smoking rates among youth have declined very little
B. there are now more female than male smokers among high school seniors
C. high smoking rates are due to the increase in wealth
D. smokers at high school are from low socio-economic backgrounds
【单选题】
According to the passage, which of the following is NOT a disadvantage of part time education? _______________ ___
A. It requires some break in one's career.
B. It tends to last too long for many people to complete a degree program.
C. It affects one's career.
D. It gives the student less time to share with the family.
【单选题】
Which of the following is NOT an advantage of distance learning? _________ ___
A. The student may choose his or her own pace.
B. The student may study at any time to his or her convenience.
C. They can pursue their chosen career while studying.
D. Their tutorial assistance comes through regular airmail, telephone, etc.
【单选题】
What benefit will distance learning program bring to a business? __________ ___
A. Recruitment of more talented people.
B. Good image of the business.
C. Better cooperation with universities.
D. Further training of employees and business growth.
【单选题】
Good distance learning program have the following characteristic EXCEPT______. ___
A. distance learning course is the same as students taking courses in campus
B. the degree should be same as on campus study
C. professor-student relationship is strictly one to one all through the course
D. includes subject evaluation tool
【单选题】
What benefit will distance learning bring to an employee of a business? ___________ ___
A. Professional growth.
B. Good relationship with the employer.
C. Good impression on the employer.
D. Higher salary.
【单选题】
In the first paragraph, what does "plastic money" (Line 6, Para.1) refer to? ______ ___
A. Dollars.
B. Online payment.
C. Credit cards.
D. Coins.
【单选题】
Which of the following is NOT true about credit cards? ____________ ___
A. Shopkeepers, among others, object to the use of credit cards because they add on the cost of the merchandise.
B. Credit card holders actually pay for their goods after the purchase has been completed.
C. The national company enjoys extensive growth because of the use of credit cards.
D. It has had the effect of increasing consumption.
【单选题】
What is the disadvantage of credit cards? _____________ ___
A. It may lead to the overgrowth of the national economy.
B. The delay in the payment of shopping goods may bring damage to shopkeepers' profits.
C. Some people may intentionally purchase goods that they cannot possibly afford.
D. Those who pay by cash at the purchase will have to pay for the cost added to the product as the interest charge of credit cards.
【单选题】
What is the main topic of the text? ________________ ___
A. Advantages and Disadvantages of Credit Cards.
B. Economic Growth Backed up by the Use of Credit Cards.
C. It can encourage great sums of consumption.
D. Credit Cards Make Life
E. asier.
【单选题】
The author's attitude towards credit card is.______________. ___
A. agreeable
B. neutral
C. humorous
D. oppositional
【单选题】
不含有割地内容的不平等条约是___。
A. 《南京条约》
B. 《北京条约》
C. 《马关条约》
D. 《辛丑条约》
【单选题】
在甲午战争后,严复翻译的《天演论》所宣传的重要思想是___。
A. “师夷长技以制夷”
B. “中学为体,西学为用”
C. “天下兴亡,匹夫有责”
D. “物竞天择,适者生存”
【单选题】
火烧圆明园发生在___期间。
A. 鸦片战争
B. 第二次鸦片战争
C. 甲午战争
D. 八国联军侵华战争
【单选题】
规定允许外国在中国办工厂的条约是___。
A. 《南京条约》
B. 《北京条约》
C. 《马关条约》
D. 《辛丑条约》
【单选题】
1895 年,日本强迫清政府签订___,割去台湾全岛及所有附属岛屿和澎湖列岛。
A. 《南京条约》
B. 《北京条约》
C. 《马关条约》
D. 《辛丑条约》