北航有限元分析与应用期末复习题答案

北航有限元分析与应用期末复习题答案
北航有限元分析与应用期末复习题答案

北航网络教育电力系统分析开卷考试考前试题与答案三

北航网络教育-《电力系统分析》开卷考试考前试题与答案(三) 一、 简答题 1. 循环功率是如何定义的? 在两端电压不相等的两端供电网络中,各线段中流通的功率可看作是两个功率分量的叠加。其一为两端电压相等时的功率;另一为取决于两端电压的差值dU 和环网总阻抗的功率,称循环功率。 2. 简述电力系统稳态运行的基本要求? 答:三相电力系统满足统经济性运行的要求,每一台发电机的输出必须接近于预先设定值;必须确保联络线潮流低于线路热极限和电力系统稳定极限;必须保持某些中枢点母线上的电压水平在容许范围内,必要时用无功功率补偿计划来达到; 区域电网是互联系统的一部分,必须执行合同规定的输送至邻网的联络线功率计划; 用故障前的潮流控制策略使事故扰动效应最小化。 3. 试说明潮流计算中如何对节点进行分类?其特点如何? 答: 1)平衡节点,一般一个系统只有一个平衡节点。在潮流分布算出以前,网络中的功率损耗是未知的,因此,至少有一个节点的有功功率P 和无功功率Q 不能给定。另外必须选定一个节点,制定其电压相角为零,作为其它节点电压相位的参考,这个节点叫基准节点。为了计算方便,常将平衡节点和基准节点设在同一个节点上。平衡节点是电压参考节点,该母线的11U δ∠是给定值,作为输入 数据,典型取标幺值1.00∠o 。潮流程序计算P 1和Q 1。因为平衡节点的P 、Q 事先 无法确定,为使潮流计算结果符合实际,常把平衡节点选在有较大调节裕量的发电机节点,潮流计算结束时若平衡节点的有功功率、无功功率和实际情况不符,就要调整其他节点的边界条件以使平衡节点的功率满足实际允许范围。2)PQ 节点,P i 和Q i 是输入数据。这类节点的有功功率P i 和无功功率Q i 是给定的,潮流计算程序计算节点电压幅值U i 和相角i δ。负荷节点和无功功率注入的联络节点都属于这类节点。有些情况下,系统中某些发电厂送出的功率在一定时间内为固定时,该发电厂母线也可以作为PQ 节点。在一个典型的潮流程序中绝大多数母线作为PQ 节点。3)PU 节点(电压控制母线),P i 和U i 是输入数据。这类节点的有功功率P i 和节点电压幅值U i 是给定的,潮流程序计算节点的无功功率Q i 和电

北航2010-2011年研究生数值分析期末模拟试卷1-3

数值分析模拟试卷1 一、填空(共30分,每空3分) 1 设??? ? ??-=1511A ,则A 的谱半径=)(a ρ______,A 的条件数)(1A cond =________. 2 设 ,2,1,0,,53)(2==+=k kh x x x f k ,则],,[21++n n n x x x f =________, ],,[321+++n n n n x x x x f ,=________. 3 设?????≤≤-++≤≤+=2 1,121 0,)(2 323x cx bx x x x x x S ,是以0,1,2为节点的三次样条函数,则b=________,c=________. 4 设∞=0)]([k k x q 是区间[0,1]上权函数为x x =)(ρ的最高项系数为1的正交多项式族,其中1)(0=x q ,则 ?=1 )(dx x xq k ________,=)(2 x q ________. 5 设???? ??????=11001a a a a A ,当∈a ________时,必有分解式,其中L 为下三角阵,当 其对角线元素)3,2,1(=i L ii 满足条件________时,这种分解是唯一的. 二、(14分)设4 9,1,41,)(2102 3 === =x x x x x f , (1)试求)(x f 在]4 9,41[上的三次Hermite 插值多项式)(x H 使满足 2,1,0),()(==i x f x H i i ,)()(11x f x H '='. (2)写出余项)()()(x H x f x R -=的表达式. 三、(14分)设有解方程0cos 2312=+-x x 的迭代公式为n n x x cos 3 2 41+ =+, (1) 证明R x ∈?0均有? ∞ →=x x n x lim (? x 为方程的根); (2) 取40=x ,用此迭代法求方程根的近似值,误差不超过,列出各次迭代值; (3)此迭代的收敛阶是多少?证明你的结论. 四、(16分) 试确定常数A ,B ,C 和,使得数值积分公式 有尽可能高的代数精度. 试问所得的数值积分公式代数精度是多少?它是否为Gauss 型的?

期末英语考试题

20道选择题(会从里面抽出一部分) 1.Economic crises destroy the capitalist system, and they grow in size and duration. 2.Stability also depends upon the flexibility of the local economy. 3.He was sentenced to do hard labor without the option of a fine. 4.She states her views very definitely_. 5.Did he actually say in so many words that there was no hope of a cure? 6.The baby felt ignored by her parents. 7.You need to convince the employers that you can do the job. https://www.360docs.net/doc/756067421.html,panies will have to do more than this if they are to survive the earthquake. 9.I don’t like this young woman; she seems a social _butterfly. 10.The novel captured___ the imagination of thousands of readers. 11.God knows. How can I endure__ six exams a week? 12.A tiny star can spark___ in the darkness. 13.There are good chances of _promotion_ in this firm. 14.Mrs. Hill is _keen__ on Tom’s marrying Susan. 15.Some professions are __stuffed__ with people who have not grown up. 16.How should this _innocent__ girl see the coldness of the letter? 17.His dominant _trait_ was to take all things into earnest consideration. 18.She tried to __undermine___ our friendship. 19.This was my big chance and I __grabed__ it with both hands. 20.The new airport will __facilitate__ tourism. 21.He came over and _shoved_ a piece of paper into my hand. 22.Shanghai is a city with a large _translent__ population. 23.I’ll __pop__ over and see you this evening. 24.A dropped cigarette is being _blamed__ for the fire. 25.They were full of __envy_ when they saw my new car. 26.The doctor tried to help _restore__ the function of his limbs. 27.Let me assure you that it was not done __intentionally___. 28.The smooth space flight, experts say, marks a big __breakthrough__ for Chinese scientists. 29.He failed to __respond_ to the medicine. 30.This medicine can _lessen__ the pain in no time. 31.The boy really enjoyed the useful and _creative_ work in science. 32.Advertising is often the most _effective__ method of promotion. 33.He __complimented__ her on her last physics paper. 34.After dinner, I took a _stroll__ around the park. 35.A hundred years ago people _scoffed_ at the idea. 36.They are determined to carry forward the _enterprise__ . 37.The conference discussed the fair ___distribution___of income and wealth. 38.Women’s social _status__ has changed much over the years. 39.Before he could find the __fitting__ word she had cut him short with a question. 40.In time you’ll __appreciate__ the beauty of this language. 41.We couldn’t _induce__the old lady to travel by air. 42.The test is used to __diagnose_ a variety of diseases.

北航计算机复试 06-14上机真题及答案

北京航空航天大学计算机系考研 复试06-14上机真题及答案 复试上机指导 1.本真题只是提供辅助作用,关键还是研友平时动手能力练习和对 算法、数据结构的理解,参加过ACM的有一定优势没参加过 的也不用紧张,北航的上机题相对于清华和北大,难度上小很 多,多练习的话,问题不大; 2.上机时,可以快速阅读所有的题目,按照从易到难的次序做题, 保证会的一定得分; 3.熟悉编程环境,熟悉c的常用函数; 4.为了快速测试代码的正确性,尤其是矩阵输入的情况,可以利用 标准输入重定向, freopen(“c:\\input.txt”,”r”,s tdin);加快测试过 程; 5.注意程序边界条件的测试; 6.如果你有什么疑问,或者我们提供的材料有问题,欢迎联系我们: bwiunbuaa@https://www.360docs.net/doc/756067421.html,提供北航计算机报考和选导师指导,或者 到https://www.360docs.net/doc/756067421.html, 给我们留言。

14年上机题 第一题,阶乘数。输入一个正整数,输出时,先输出这个数本身,跟着一个逗号,再输出这个数的各位数字的阶乘和,等号,阶乘和的计算结果,并判断阶乘和是否等于原数,如果相等输出Yes,否则输出No。题目说明输入的正整数以及其各位阶乘和都不会超 出int型的表示范围。 输入样例1: 145 输出样例1: 145,1!+4!+5!=145 Yes 输入样例2: 1400 输出样例2: 1400,1!+4!+0!+0!=27

No 第二题,五子棋。输入一个19*19的矩阵,只包含数字0、1、2,表示两人下五子棋的棋牌状态,1、2分别表示两人的棋子,0表示空格。要求判断当前状态下是否有人获胜(横向、竖向或者斜线方向连成5个同色棋子)。题目说明输入样例保证每条线上至多只有连续5个同色棋子,并且保证至多只有1人获胜。如果有人获胜,输出获胜者(1或2)加一个冒号,接着输出获胜的五连珠的第一个棋子的坐标,从上到下从左到右序号最小的为第一个,序号从1开始编号。如果无人获胜,输出no。 样例略。 第三题,排版题。输入若干行字符,表示某电影的演职员表,每行只有一个冒号,冒号前面是职位,冒号后面是姓名,要求把各行

大一英语期末期末考试试题内含答案[1]

大学英语预备阶段练习(一) (Unit 1~4) ⅠWord Building Directions: Fill in the blanks with the correct form of the words given in the brackets. 1.Thank you very much for your ____ advice. I followed it and succeeded at last. (value) 2.His business has ____ rapidly since his brother came to help. (development) 3.After a two-day discussion, we finally found a ____ to the difficult problem. (solve) 4.Prices ____ high for quite a while .People began to complain about it. (remaining) 5.I don’t think it ____ to finish all the work today. We can go on with it tomorrow.(necessity) 6.It is obviously not ____ to leave a 3-year-old boy alone at home. (properly) 7.The tourists saw a beautiful ____ when they climbed onto the top of the mountain.(scene) 8.Traveling in the desert is a challenging ____ to most people. ( inexperience) 9.____, I don’t think it possible to finish the task in two days. (person) 10.The government must make sure that the economy is developed in the right ____.(direct) ⅡVocabulary and Structure Directions: Choose the best one from the four choices to complete the sentence. 11.The temperature ____ throughout the day in that part of the country. A. very B. remains C. differs D. varies 12.The game is full of violence and will certainly have a bad ____ on young players. A. meaning B. pain C. loss D. influence 13.The warm-hearted elderly lady downstairs is always ____ to help others. A. real B. ready C. practical D. polite 14.The question is ____ difficult in the exam today. Don’t you think so? A. therefore B. since C. rather D. otherwise 15.She used to live in a lovely ____ building near the sea. A. 3-story B. 3-stories C. 3-classed D. 3-classes 16.There are different ____ of transport in big cities for you to choose when you go out. A. means B. mean C. meanings D. meaning 17.They did not take a rest until the job was ____ finished. A. straightly B. specially C. completely D. fairly 18.The bookstore owner ____ the old magazines with a new ones to attract more readers. A. required B. reviewed C. repeated D. replaced 19.Would you like to buy the book? It is ____ reading. A. worthy B. firm C. further D. worth 20.She wears sunglasses to ____ her eyes from the sunshine in summer. A. prepare B. produce C. protect D. provide 21.We all like her very much for her pleasant ____: kind, gentle and warm-hearted. A. character B. chance C. chairman D. skills 22.All the students enjoyed the wonderful ____ by the professor that afternoon. A. discussion B. lecture C. advice D. solution 23.If you have confidence in yourself first, you will not be _______ by others easily. A.won B. doubled C. defeated. D. delayed 24.The little girl developed a strong _______ on her new friends.

北航数电2015试题及答案

数字电子技术基础(A 卷)(无答案) 一. 解答下列问题(共40分,每小题5分) 1. 十进制数 X = 117,其ASCII 码表示为: 。 在8位机器中,[X]补 = ,[-X]补 = 。 2. 已知逻辑函数:()F A C BC A B CD =+++,直接用反演规则写出其反函数和对偶函数。 3. 用卡诺图化简逻辑函数∑∑+=)15,1013,8,2,1()14,12,7,6,0(44d m F 4. 用OC 门驱动发光二极管电路如图,若V F =2V ,I F =20mA ,试完善电路并计算电阻R=? 5. 画出图示电路的输出波形 6. 主-从JK 触发器,已知CP 、J 、K 信号波形如图示,画出输出波形(初始状态为0)。 A B C Y Y A B C & E n

7. 分析函数 F AB ABC =+ 所组成的电路存在何种险象。 8. 图示电路中触发器: 建立时间 t su = 20ns , 保持时间 t h = 5ns , 传输迟延时间t pdcp-Q,/Q = 30ns , 门G 迟延t pd G = 10ns , 时钟脉冲F max = ? 二. 逻辑函数 (,,)F A B C ABC BC AC =++(本题共14分,每小题7分) 1. 用3-8译码器及适当门电路实现。 2. 用“四选一”数据选择器及适当门电路实现。 CP J K Q D Q CP CK G

三. 分析下列电路所实现的逻辑功能(本题共16分,每小题8分) 1. 由2-5-10进制异步计数器构成的电路。 2. 由74LS163构成计数器电路。 四. 某同步时序系统的原始状态表如图示(本题15分) 1. 用隐含表法化简; 2. 自然序编码; 3. 用JK 触发器及适当门设计电路; 4. 检查是否可以自启动。 CP Q A Q B Q C Q D CK 1 CK 2 R D X Qn 0 1 A B/0 A/1 B C/0 A/0 C C/0 B/0 D E/0 D/1 E C/0 D/0 P Q A Q B Q C Q D T PC A B C D L P Q A Q B Q C Q D T PC A B C D L “1” “1”

大一期末考试英语试题

01 Passage 1 Hypnotism (催眠术) is very old. Thousands of years ago people started to use it in Egypt. The use of hypnotism has grown very much since that time. Today, doctors and scientists are in almost every country hypnotize people to help them with their problems. What is hypnotism, and how does it work? Many people think that a hypnotist puts people to sleep. Then he makes the hypnotized people do strange things. This is not what a hypnotist does. Hypnotism is really just a way to relax the mind and body. What are some of the uses of hypnotism? We go to a hypnotist because w e have a problem. The problem makes us unhappy. The hypnotist asks us to think hard about something and relax. When we are relaxed, t he hypnotist gives us some ideas to help us with our problems. Hypnotism can help people to remember things. The police sometimes ask hypnotists to help them. For example, a man sees an accident. He forgets the license number of the car he sees. If he is hypnotized he may remember it. The police can then find the car and catch the driver. People who are hypnotized can also make mistakes or say something that isn't true. People remember what they think they saw. That may not be what really happened. The police don't hypnotize people who do something wrong. Why not? People who are hypnotized may say something that isn't true. A person who has done something bad has a good reason to say something that isn't true. 1. Hypnotist helps people by ____. [A] putting them to sleep [B] helping them to get relaxed [C] offering his ideas about their problems [D] making them forget their problems 2. When hypnotized, some people may say something that is not true, because ____. [A] they do not remember what has happened [B] they remember what they think has happened [C] they do not know what has happened [D] they are not interested in what has happened 3. According to the passage, which of the following is TRUE?____ [A] Hypnotism is very different form what it used to be. [B] When a person is hypnotized, his body gets relaxed, while his mind works hard. [C] Hypnotism is much more widely used today than it was thousands of years ago. [D] When hypnotized, a person will do something strange. 4. The passage mainly talks about ____. [A] how hypnotism works [B] the development of hypnotism [C] the use of hypnotism [D] the wonder of hypnotism

大一英语期末考试试卷

Testing Paper Unit 1, 4, 5 Sky:陈人智、吴斌、马琴、苏红光 Group________ Name__________ Score_________ I. Listening (30%) I).Listen to the dialog between Gary and Paul and choose the best answer to each of the questions you hear on the recording. (2×5=10) (Unit 1 Part II Listening I) ()1.A.Eating and drinking. B. Dancing to the music. C. Standing around at the party. D. Talking with his girlfriend. ()2.A.Women who stay home doing housework. B. Women who stimulate his intellect. C. Women who pursue their own careers. D. Women who enjoy reading novels. ()3.A. Cleaning and cooking. B. Fixing things around the house. C. Washing the car and collecting the trash. D. Watching television and taking out the garbage. ()4.A.They are the same as his. B. They are quite progressive for the times. C. They reflect the views of earlier generations. D. They were shaped by their own family life. ()5.A. Visit his friend, Bob. B. Remain at the party to try to make new friends. C. Meet a woman who shares his interest in literature. D. Return home alone and spend the night with his dog. II).Listen to the passage and decide whether the following statements are true or false. Write "T" for True and "F" for False in the spaces provided. (2×5=10) (Unit 4 Part III Practice One) ______6.Women and men play different roles in society because their physical structures are very different. ______7.Girl babies were found to differ a lot from boy babies in birth length, weight and irritability. ______8.Our parents, school, television and the Internet show us how we should behave. ______9.Male cartoon characters are usually more prominent than female characters. ______10.Nowadays, women are no longer expected to play their traditional roles. III).Listen to the interview and complete the following sentences with the exact words you hear(1×10=10) (Unit 1 Part Four Section III) 11. You throw a little boy a ball, and he will try to _______it 12. A baby boy will pick up a stick and _______it_______ a gun 13. When boys play with Barbie dolls, they like to _______their hair_______ 14. Boys couldn't_______ _______ if their hair is untidy 15. Boys grow their fingernails long because they're too _______ to _______ them. 16. At an early age, boys are attracted to _______ II Words and Expressions (40%) 1.assign __________________ 2.culturally__________________ 3.genetic _________________ 4.sex-biased__________________ 5.neatness ________________ 6.nursery_____________________ 7. carry over_______________ 8.fall behind __________________

北航期末英语考试题与答案

北京航空航天大学 2005-2006 学年第二学期期末《大学英语II》 考试卷 班级______________学号 _________ 姓名______________成绩 _________ 2006年6月28日

北京航空航天大学2005级2005——2006学年第二学期 大学英语二级期末考试 B卷 系别:姓名:学号: 请用铅笔将所有答案涂/写在答题卡/纸上,做在此试卷上无效。 Part I. Listening Comprehension (30 points) Section A Directions: In this section you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation and question will be spoken once. After each question there will be a pause. You must read the four choices marked A), B), C) and D), and decide which one is the best answer. Then mark the corresponding letter on the ANSWER SHEE with a single line through the center. 1. A) He stayed in his company. B) He was away on business in London. C) He went to London with his wife. D) He enjoyed his holiday in London. 2. A) She was absent from the party. B) She organized the party. C) She was present for the party. D) She was invited to the party. 3. A) Bob's. B) Tom's. C) The man's. D) The woman's. 4. A) The one the woman bought yesterday. B) Both the man's and Jack's. C) Jack's. D) The man's. 5. A) That the woman should not worry. B) That Mr. Smith is very kind. C) That he is worried. D) That he likes Mr. Smith. 6. A) 8:00. B) 8:10. C) 8:25. D) 7:45. 7. A) He does not like Mr. Smith and his friends. B) He looks after them carefully. C) He makes them work even on Sunday. D) He is strict. 8.A) Rainy.

北航数值分析报告第三次大作业

数值分析第三次大作业 一、算法的设计方案: (一)、总体方案设计: x y当作已知量代入题目给定的非线性方程组,求(1)解非线性方程组。将给定的(,) i i

得与(,)i i x y 相对应的数组t[i][j],u[i][j]。 (2)分片二次代数插值。通过分片二次代数插值运算,得到与数组t[11][21],u[11][21]]对应的数组z[11][21],得到二元函数z=(,)i i f x y 。 (3)曲面拟合。利用x[i],y[j],z[11][21]建立二维函数表,再根据精度的要求选择适当k 值,并得到曲面拟合的系数矩阵C[r][s]。 (4)观察和(,)i i p x y 的逼近效果。观察逼近效果只需要重复上面(1)和(2)的过程,得到与新的插值节点(,)i i x y 对应的(,)i i f x y ,再与对应的(,)i i p x y 比较即可,这里求解 (,)i i p x y 可以直接使用(3)中的C[r][s]和k 。 (二)具体算法设计: (1)解非线性方程组 牛顿法解方程组()0F x =的解* x ,可采用如下算法: 1)在* x 附近选取(0) x D ∈,给定精度水平0ε>和最大迭代次数M 。 2)对于0,1, k M =执行 ① 计算() ()k F x 和()()k F x '。 ② 求解关于() k x ?的线性方程组 () ()()()()k k k F x x F x '?=- ③ 若() () k k x x ε∞∞ ?≤,则取*()k x x ≈,并停止计算;否则转④。 ④ 计算(1) ()()k k k x x x +=+?。 ⑤ 若k M <,则继续,否则,输出M 次迭代不成功的信息,并停止计算。 (2)分片双二次插值 给定已知数表以及需要插值的节点,进行分片二次插值的算法: 设已知数表中的点为: 00(0,1,,) (0,1,,)i j x x ih i n y y j j m τ=+=???=+=?? ,需要插值的节点为(,)x y 。 1) 根据(,)x y 选择插值节点(,)i j x y : 若12h x x ≤+ 或12 n h x x ->-,插值节点对应取1i =或1i n =-,

北京市海淀区2018届高三第一学期期末考试英语试题

海淀区高三年级第一学期期末练习 英语2018.01本试卷共12页,共150分。考试时长120分钟。考生务必将答案答在答题卡上,在试卷上作答无效。考试结束后,将答题纸交回。 第一部分:听力理解(共三节,30分) 第一节(共5小题;每小题1.5分,满分7.5分) 听下面五段对话。每段对话后有一道小题,从每题所给的A、B、C三个选项中选出最佳选项。听完每段对话后,你将有10秒钟的时间来回答有关小题和阅读下一小题。每段对话你将听一遍。 1. When did the fire probably break out? A. At 9 pm. B. At 8 pm. C. At 7 pm. 2. What does the man usually do after waking up in the morning? A. Brush his teeth. B. Check the weather forecast. C. Go out. 3. What’s the weather lik e in Beijing? A. Hot. B. Cold. C. Windy. 4. Where does the man like watching movies? A. On cellphones. B. In rooms with WiFi. C. In the theater. 5. What will the woman probably do? A. Clear useless data. B. Remove unwanted apps. C. Buy a new phone. 第二节(共10小题;每小题1.5分,15分) 听下面四段对话。每段对话后有几道小题,从每题所给的A、B、C三个选项中选出最佳选项。听每段对话前,你将有5秒钟的时间阅读每小题。听完后,每小题将给出5秒钟的作答时间。每段对话你将听两遍。 听第6段材料,回答第6至7题。 6. What is the probable relationship between the two speakers? A. Boss and secretary. B. Receptionist and guest. C. Ticket agent and customer. 7. When is the Chinese Music Concert? A. On 15th. B. On 28th. C. On 30th. 听第7段材料,回答第8至9题。 8. What does the man want to do? A. V isit the manager. B. Rent an apartment. C. Ask for directions. 9. What is the man expected to bring with him? A. A n application form. B. The MapQuest. C. His driver’s license. 听第8段材料,回答第10至12题。 英语第1页(共11页)

北航数值分析大作业第二题

数值分析第二次大作业 史立峰 SY1505327

一、 方案 (1)利用循环结构将sin(0.50.2)() 1.5cos( 1.2)() {i j i j ij i j i j a +≠+==(i,j=1,2,……,10)进行赋值,得到需要变换的 矩阵A ; (2)然后,对矩阵A 利用Householder 矩阵进行相似变换,把A 化为上三角矩阵A (n-1)。 对A 拟上三角化,得到拟上三角矩阵A (n-1),具体算法如下: 记A(1)=A ,并记A(r)的第r 列至第n 列的元素为()n r r j n i a r ij ,,1,;,,2,1) ( +==。 对于2,,2,1-=n r 执行 1. 若 ()n r r i a r ir ,,3,2) ( ++=全为零,则令A(r+1) =A(r),转5;否则转2。 2. 计算 () ∑+== n r i r ir r a d 1 2 )( ()( )r r r r r r r r r r d c a d a c ==-=++则取,0sgn ) (,1)(,1若 )(,12r r r r r r a c c h +-= 3. 令 () n T r nr r r r r r r r r R a a c a u ∈-=++) ()(,2)(,1,,,,0,,0 。 4. 计算 r r T r r h u A p /)(= r r r r h u A q /)(= r r T r r h u p t /= r r r r u t q -=ω T r r T r r r r p u u A A --=+ω)()1( 5. 继续。 (3)使用带双步位移的QR 方法计算矩阵A (n-1)的全部特征值,也是A 的全部特征值,具体算法如下: 1. 给定精度水平0>ε和迭代最大次数L 。 2. 记n n ij n a A A ?-==][) 1()1()1(,令n m k ==,1。

相关文档
最新文档