【单选题】
对于额定转速为3000r/min的汽轮机,其超速试验应连续做两次,两次的转速差不超___r/min。
A. 60;
B. 30;
C. 20;
D. 18。
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相关试题
【单选题】
汽机进水紧急停机后___小时内禁止启动。
【单选题】
汽机进水紧急停机再启动时上、下缸温差应<42℃,转子偏心度<___mm。
【单选题】
正常停机到___额定负荷时,应打开汽机各疏水门。
【单选题】
汽轮机停止后,每1小时检查并记录一次以下参数直到高压缸调节级金属温度低于___℃:高中压上下缸温差、胀差、汽缸膨胀、盘车电流及其晃动值、转子偏心度、凝汽器水位,发现异常及时处理。
【单选题】
缸温___℃以上时严禁退出凝结器水位、加热器水位、除氧器水位、汽缸温度等测点。
【单选题】
1号机组正常运行润滑油压应在___MPa
A. 0.098~0.18
B. 0.15~0.18
C. 0.087 ~0.18
【单选题】
机组正常运行时冷油器出口油温维持___℃。
A. 38~42
B. 38~49
C. 40~45
【单选题】
机组正常运行时各轴承回油温度正常应小于___℃
【单选题】
EH油高压蓄能器氮气压力___~9.8MPa。
【单选题】
EH油低压蓄能器氮气压力0.35~___MPa
【单选题】
正常运行主、再热蒸汽温差应小于±___℃。
【单选题】
异常情况下再热汽温度不允许低于主汽温度___℃,运行时间不超过15分钟。
【单选题】
正常运行时主汽温度、再热汽温度左右两侧偏差应小于___℃。
【单选题】
异常情况下任意4小时内主汽温度、再热汽温度左右两侧偏差不大于42℃,运行时间不能超过___分钟。
【单选题】
热态启动汽轮机连续盘车时间不少于___小时或机组处于连续不间断盘车状态。
【单选题】
机组冲动前上下缸温差应小于规定值___。
【单选题】
轴封蒸汽和转子表面的温差不应超过___℃。
【单选题】
机组冲动前凝汽器建立真空不小于___kPa
【单选题】
低压汽封内的蒸汽温度维持在___,以防汽封体可能的变形和损坏汽轮机转子
【单选题】
机组正常运行时润滑油温在43~49℃,各轴承的回油温度<___℃,回油量正常。
【单选题】
机组正常运行时主油箱油位应保持在+___~-180mm。
【单选题】
1号机主油箱油位高二值为___。
A. +319mm
B. +600mm
C. +500mm
【单选题】
1号机主油箱油位高一值为___。
A. +100mm
B. +37 mm
C. +56 mm
【单选题】
1号机主油箱油位低一值为___。
A. -180mm
B. -300mm
C. -250mm
【单选题】
1号机主油箱油位低二值为___
A. -400mm
B. -450mm
C. -260mm
【单选题】
当油箱油温低于___℃,禁止启动盘车。
【单选题】
主油箱负压保持在___pa,
A. -400~-500
B. -50~-100
C. -50~-200
【单选题】
顶轴油泵入口压力高于___MPa时, 顶轴油泵启动允许。
【单选题】
启机时,当机组转速>___r/min时,停顶轴油泵。
【单选题】
停机时,当机组转速<___r/min时,起顶轴油泵。
【单选题】
确认轴封供汽停止、高压缸调节级金属温度低于___℃,且高、中压缸上下缸金属温差均小于42℃时,方可停止盘车装置的运行。
【单选题】
确认主机盘车装置、顶轴油泵及密封油系统均已停止运行。高中压缸最高金属温度低于___℃,并且各轴承金属温度均在正常范围内,方可停止交流润滑油泵。
【单选题】
机组正常运行时,EH油箱油位应保持在___mm。
A. 500-650
B. 400-500
C. 370-450
【单选题】
给水泵小汽轮机MEH控制系统的控制方式中,锅炉自动方式能通过把从锅炉协调控制系统CCS来的给水流量信号,转换成转速定值信号,输入转速控制回路控制小汽轮机的转速。转速控制范围是___r/min。
A. 0-6000r
B. 2500-6000
C. 3000-6000
【单选题】
机组启动时,上缸调节级处金属温度在___℃之间称为温态启动。
A. 150~200;
B. 150~200;
C. 120~415;
D. 250~300
【单选题】
汽轮机冷态启动时,一般控制升速率为___r/min。
A. 200~250;
B. 300~350;
C. 100~150;
D. 400~500。
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【单选题】
中国共产党要把______这场伟大的革命进行好,党必须进行自我革命,全面增强党的执政本领。 ___
A. 新时代经济体制改革
B. 新时代政治体制改革
C. 新时代坚持和发展中国特色社会主义
D. 新时代中国改革开放
【单选题】
中国特色社会主义道路是实现社会主义现代化、创造人民美好生活的______。___
A. 理论依据
B. 必由之路
C. 根本保障
D. 行动指南
【单选题】
确保党始终总揽全局、协调各方,必须____。___
A. 得民心者得天下
B. 坚持和完善党的领导的体制机制
C. 学习达国家的经验
D. 选举优秀领导人
【单选题】
增强面对新时代新使命,必须在全党营造善于学习、勇于实践的浓厚氛围,建设马克思主义____政党。 ___
A. 人民型
B. 事业型
C. 研究型
D. 学习型
【单选题】
必须坚持党的( ),既要充分发扬民主,又要善于集中。 ___
A. 集中民主制
B. 民主集中制
C. 多党合作制
D. 全民民主制
【单选题】
党是最高政治领导力量,是推进伟大事业的( )保证。 ___
【单选题】
According to one study, what do green spaces do to people? ___
A. Improve their work efficiently.
B. Add to their sustained happiness.
C. Help them build a positive attitude towards life.
D. Lessen their concerns about material well-being.
【单选题】
What does Dr. White say people usually do to make themselves happier? ___
A. Earn more money.
B. Settle in an urban area.
C. Gain fame and popularity.
D. Live in a green environment.
【单选题】
What does Dr. White try to find out about living in a greener urban area? ___
A. How it affects different people.
B. How strong its positive effect is.
C. How long its positive effect lasts.
D. How it benefits people physically.
【单选题】
What did Dr. White’s research reveal about people living in a green environment? ___
A. Their stress was more apparent than real.
B. Their decisions required less deliberation.
C. Their memories were greatly strengthened.
D. Their communication with others improved.
【单选题】
According to Dr. White, what should the government do to build more green spaces in cities? ___
A. Find financial support.
B. Improve urban planning.
C. Involve local residents in the effort.
D. Raise public awareness of the issue.
【单选题】
The survey by the Kaiser Family Foundation is mentioned to illustrate the idea that . ___
A. kids don’t always follow parents’ rules
B. only few parents believe the good news
C. much media use results in bad health
D. parents’ rules make a huge difference
【单选题】
What did the kids do when parents set any time or content limits, according to the Kaiser Family Foundation? ___
A. They cut down on their screen time.
B. They appreciated their parents’ love.
C. They spent more time staying outdoor.
D. They accepted parents’ rules unwillingly.
【单选题】
What will Kenneth Ginsburg most probably suggest that parents should do? ___
A. Avoid setting firm rules.
B. Avoid ruling with an iron grip.
C. Set rules after family discussion.
D. Set rules that are easy to understand.
【单选题】
Margaret Broe -Fitzpatrick finds it impossible. ___
A. to achieve just- right parenting
B. to keep track of everything done by the kids
C. for the kids to face rules alone
D. for the kids to observe rules without protest
【单选题】
The passage is mainly intended for parents . ___
A. whose kids have difficulty in self- discipline
B. whose kids are addicted to media use
C. who have doubts about setting rules
D. who are too busy to care for their kids
【单选题】
The word “it” (Para. 2) most probably refers to. ___
A. the lack of stable communities
B. the breakdown of informal information channels
C. the increased mobility of families
D. the growing number of people moving from place to place
【单选题】
The main problem people may encounter today arises from the fact that . ___
A. they have to learn new things consciously
B. they lack the confidence of securing reliable and trustworthy information
C. they have difficulty obtaining the needed information readily
D. they can hardly carry out casual communications with an extended family
【单选题】
From the passage we can infer that _______. ___
A. electronic mail will soon play a dominant role in transmitting messages
B. it will become more difficult for people to keep secrets in an information era
C. people will spend less time holding meetings or conferences
D. events will be reported on the spot mainly through satellites
【单选题】
Technology facilitates _______. ___
A. sharing information
B. storing and sending information
C. providing people with easy access to more information
D. all of the above
【单选题】
We can learn from the last paragraph that _______. ___
A. it is necessary to obtain as much
B. people should make the best use of the information
C. we should realize the importance of accumulating information
D. it is of vital importance to acquire needed information efficiently
【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.