2010年硕士研究生入学考试试题

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2010年408真题及答案解析

2010年全国硕士研究生入学统一考试计算机科学与技术学科联考计算机学科专业基础综合试题一、单项选择题：第1~40小题，每小题2分，共80分。

下列每题给出的四个选项中，只有一个选项最符合试题要求。

1.若元素a 、b 、c 、d 、e 、f 依次进栈，允许进栈、退栈操作交替进行，但不允许连续三次进行退栈操作，则不．可能得到的出栈序列是______。

A ．d c e b f a B ．c b d a e f C ．b c a e f d D ．a f e d c b2.某队列允许在其两端进行入队操作，但仅允许在一端进行出队操作。

若元素a 、b 、c 、d 、e 依次入此队列后再进行出队操作，则不．可能得到的出队序列是______。

A ．b a c d e B ．d b a c e C ．d b c a e D ．e c b a d3.下列线索二叉树中（用虚线表示线索），符合后序线索树定义的是______。

A ．B ．C ．D ．4.在右图所示的平衡二叉树中，插入关键字48后得到一棵新平衡二叉树。

在新平衡二叉树中，关键字37所在结点的左、右子结点中保存的关键字分别是______。

A ．13，48B ．24，48 C ．24，53D 、24，905.在一棵度为4的树T 中，若有20个度为4的结点，10个度为3的结点，1个度为2的结点，10个度为1的结点，则树T 的叶结点个数是______。

A ．41 B ．82 C ．113 D ．1226.对n （n ≥2）个权值均不相同的字符构造成哈夫曼树。

下列关于该哈夫曼树的叙述中，错误．．的是______。

A ．该树一定是一棵完全二叉树。

B ．树中一定没有度为1的结点。

C ．树中两个权值最小的结点一定是兄弟结点。

D ．树中任一非叶结点的权值一定不小于下一层任一结点的权值。

7.若无向图G=（V , E ）中含有7个顶点，要保证图G 在任何情况下都是连通的，则需要的边数最少是_____。

2010考研数三真题及解析

2010年全国硕士研究生入学统一考试数学三试题一、选择题(1~8小题,每小题4分,共32分.下列每题给出的四个选项中,只有一个选项符合题目要求的,请将所选项前的字母填在答题纸．．．指定位置上.)1 1 x ,则a等于( )(1)若limx0 x x a e1(A)0. (B) 1. (C) 2. (D) 3.(2)设y1, y2 是一阶非齐次微分方程y p x y q x的两个特解,若常数，使y1 y2 是该方程的解,y1 y2 是该方程对应的齐次方程的解,则( )1(A),(B) .(C) ,. (D) .【答案解析】见真题理论验证强化指导部分数二试题一(2).(3)设函数f x , g x具有二阶导数,且g x 0 ,若g x0a 是g x 的极值,则f g x 在x0 取极大值的一个充分条件是( )(A) f a 0. (B) f a 0 . (C) f a 0 . (D)f a 0 .x(4) 设 f xln 10 x g x , x h x ,e 10 ,则当 x 充分大时有( ) (A) g xh xf x. (B) hxg xf x.(C) fx g xh x.(D) g x f x h x .(5) 设向量组 I :1, 2,r 可由向量组II :1,2,s 线性表示,下列命题正确的是( )(A) 若向量组I 线性无关,则rs .(B) 若向量组I 线性相关,则r s . (C) 若向量组II 线性无关,则r s . (D) 若向量组II 线性相关,则r s .(6) 设 A 为4阶实对称矩阵,且 A 2A O ,若 A 的秩为3,则 A 相似于 ()1 1(A)1 .(B)1 .1 11 1(C) 1.(D)1.110, x 01(A) 0.(B).(C)e1.(D) 1e1.为1,3上均匀分布(8) 设 f 1(x ) 为标准正态分布的概率密度, f 2 (x ) 的概率密度,若af x 1( )x 0 f x( )( a 0, b 0)bf 2( )x x 0为概率密度,则a ,b 应满足 ( )(A) 2a3b 4. (B) 3a2b 4. (C) a b 1.(D) ab 2.二、填空题(9~14小题,每小题4分,共24分.请将答案写在答题纸．．．指定位置上.)x yt 2 x2 确定,则dy. (9) 设可导函数 yy x ( )由方程e dtx sin t dt dxx 01 (10)设位于曲线 y( e x ) 下方, x 轴上方的无界区域为G ,则G 绕 x轴旋转一周所得空间区域的体积是.(11) 设某商品的收益函数为R (p ),收益弹性为1p 3 ,其中 p 为价格,且R (1) 1 ,则R (p ) =.(7) 设随机变量 X 的分布函数 F x ( ) 2 1e x ,( )0 x 1 ,则 PX1=x1(12) 若曲线 y x 3 ax 2 bx 1有拐点(1,0) ,则b.(13) 设 A ,B 为3阶矩阵,且 A 3, B 2 , A1B 2 ,则A B1.n212(14)设X X 1, 2, ,X n是来自总体N (,) (0) 的简单随机样本,统计量TXi ,n i 1则ET .三、解答题(15~23小题,共94分.请将解答写在答题纸．．．指定位置上.解答应写出文字说明、证明过程或演算步骤.) (15) (本题满分10分)求极限 lim (xx 11)ln 1x .(16) (本题满分10分)计算二重积分(x y dxdy )由曲线 x 1y 2 与直线 x2y 0 及Dx 2y 0围成.(17) (本题满分10分) 求函数uxy2yz 在约束条件x 2y 2z 210 下的最大值和最小值.(18)(本题满分10分)(I ) 比较1ln tln 1tndt与1t nln t dt n 1,2,的大小,说明理由．1n( II ) 记u nln t ln 1t dt n 1,2,,求极限nli m u n ．(19) (本题满分10分)设函数 f (x ) 在0,3上连续 , 在0,3内存在二阶导数 , 且22f (0)f x dx ( ) f (2) f (3),( I ) 证明存在(0,2) ,使 f ()f (0); ; ( II ) 证明存在(0,3) ,使 f()0 ．(20)(本题满分11分)11 a设A1 ， b11已知线性方程组Ax b 存在2个不同的解． ( I ) 求,a ;( II ) 求方程组Ax b 的通解. (21)(本题满分11 分) 1 (1,2,1)T,求a ,Q ．(22) (本题满分11分) 设二维随机变量(X Y , ) 的概率密度为2f x y ( , )Ae 2x 2xy y2,x,y ,求常数 A 及条件概率密度 f Y X |(y x | ) ．(23)(本题满分11分) 箱中装有6个球,其中红、白、黑球的个数分别为1,2,3 个,现从箱中随机取出2个球, 记 X 为取出的红球个数,Y 为取出的白球个数.( I ) 求随机变量 (X Y ,) 的概率分布；0 设A 141 43a ,正交矩阵 Q 使得 Q T AQ 为对角矩阵,若 Q 的第 1 列为 a( II ) 求Cov X Y( , ) .2010年全国硕士研究生入学统一考试数学三试题参考答案一、选择题(1)【答案】 (C). 【解析】limx1 1 a exlim x1 1e x1axlimx11e xaxe xlim x1e x axe xx x xx x x1e x axe x lim lim 1 a 1x 0 x x 0 x所以a 2.(2) 【答案】 (A)．【解析】因y 1 y 2 是 y P x y 0 的解,故y 1 y 2 P xy 1y 20,所以y 1P x y1y 2p x y ( ) 20 ,而由已知 y 1P x y1q x, y 2P x y2q x,所以q x0,①又由于一阶次微分方程 ypx yq x是非齐的,由此可知 qx0 ,所以0．由于y 1y 2 是非齐次微分方程 yPx yq x的解,所以y 1 y 2 P x y 1 y 2q x,整理得y 1P x y1y 2P x y2q x ,即q xq x,由q x 0 可知1,②由①②求解得,故应选(A)．(3)【答案】 (B).【解析】f g x ( ) f g x ( )g x ( ) ,f g x( ) fg x ( )g x ( ) fg x ( )g x ( )2fg x ( )g x( )由于g (x 0 ) a 是g (x ) 的极值,所以g x ( 0)0 .所以f g x ( 0 )f gx ( 0 )g x( 0 )fa gx ( 0 )由于g x ( 0 ) 0,要使f g x( )0,必须有f a ( ) 0 ,故答案为B.(4)【答案】 (C).x【解析】因为 lim ( ) lim e 10 lim 10x 1 ,所以,当 x 充分大时,h x ( )g x ( ) .xg x ( )xxx1091又因为 limf x ( ) lim ln 10 xlim 10 ln x x 10 lim ln 9xxg x ( ) xxx1 xx81ln x10 9lim x 10 92 lim l x 10! lim 10 .x1xxxx 所以当 x 充分大时, f x ( ) g x ( ) ,故当 x 充分大, f x ( ) g x ( )h x ( ) .(5) 【答案】 (A)．【解析】由于向量组 I 能由向量组 II 线性表示,所以r (I) r (II) ,即r (1, ,r) r (1, , s ) s 若向量组 I 线性无关,则 r (1, ,r) r ,所以 rr (1, ,r )r (1, ,s )s ,即r s ,选(A).(6) 【答案】 (D). 【解析】设为 A 的特征值,由于 A 2A O ,所以20 ,即 (1)0 ,这样 A 的特征值只能为 -1 或 0. 由于 A 为实对称矩阵 , 故 A 可相似对角化 , 即11A,r A ()r ()3,因此,1,即 A1.11(7) 【答案】 (C).【解析】离散型随机变量的分布函数是跳跃的阶梯形分段函数,连续型随机变量的分布函数是连续函数.观察本题中F (x ) 的形式,得到随机变量 X 既不是离散型随机变量,也不是连续型随机变量,所以求随机变量在一点处的概率,只能利用分布函数的定义.根据分布函数的定义,函数在某一点的概率可以写成两个区间内概率的差,即P X 1P X1P X 1 F1 F11 e1e1,故本题选(C).(8) 【答案】 (A).x 21 ,1x 3【解析】根据题意知, f 1x(x),f 2x2 140,其它利用概率密度的性质:f x dx1,故a31 a 3f x dx af 1x dxbf 2 x dx2f 1x dxb4 dx24 b1所以整理得到2a 3b 4,故本题应选(A).二、填空题 (9)【答案】1.x y2x2【解析】e t dtxsin t dt ,令x 0,得 y 0,等式两端对 x 求导：e(x y )2(1dydx ) 0xsin t dt 2x sin x 2 ．dydy将x0, y 0代入上式,得10 .所以1.dxxdx x 02(10)【答案】4【解析】根据绕 x 轴旋转公式, 有2dxVey dxe1ln 2 xe1d ln ln 2x xarctan lnxe2442 .1 33P1.(11)【答案】 pedR p 3dR 1212【解析】由弹性的定义,得1 p ,所以pdp ,即 ln Rln p pC , dp R R p313又R11,所以 C1 .故ln Rln p 1 p 1 ,因此 R p e 3p1.3 33(12)【答案】b3.【解析】函数为 yx 3ax 2bx 1 ,它的一阶导数为 y 3x 2 2ax b ; 二阶导数为ay6x 2a,又因为1,0是拐点,所以 yx10 ,得3过点1,0,所以将x1,y 0 代入曲线方程,得b 3.(13) 【答案】3. A A (1B B )【解析】由于1( E AB B )1B1A ,所以1 1 11B B )A AB B因为 B2 ,所以 B1 B B1321 3 .2(14)【答案】22.1 ( B AA A111 2B,因此1 A BAA【解析】 E T EnXi2 1EnXi21nEX2E X222.n i1n i 1n 三、解答题11ln x1 lnx x 1ln x x1ln e x11lnxlimlim(15)【解析】 lim x x 1lim e ln xe xln xexln xxx其中 ln x xln x x1ln x x ln x xln( e 1) (e 1) e 1ln x e 1ln x ln x1 lim lim limlim e x ( 1)1.xln xx 1xx ln x x x故原式e1.(16)【解析】积分区域 DD 1 D 2 ,1 x y ,0 y1,2y x1y 2D 2x y , 1y 0,2y x1y 2xy3dxdyx 33x y 2 3xy 2y 3 dxdyDD因为区域 D 关于 x 轴对称 , 被积函数 3x 2 y y 3 是 y 的奇函数 ,所以3x 2y y dxdy30．Dx y dxdy3x 3 3xy dxdy 22x 3 3xy dxdy 221DDD 12xln xx211 x 43 x y 22dy2019 4 y 42y 2 1 4 dy 1415 .42(17)【解析】令 F x y z,, ,xy 2yz x 2 y 2 z 2 10,用拉格朗日乘数法得F xy 2x 0,F yx 2z2y0,F z2y 2z 0, F x 2y 2z 2100,又因为该问题必存在最值,并且不可能在其它点处,所以u m ax5 ,u m in5 5 ．(18) 【解析】 (I)当0x 1时0 ln(1x )x,故ln(1t )nt n ,所以ln tln(1t )nln t t n ,则01ln t ln(1t )ndt1ln t t dt n n 1,2, .(II)1 ln t t dt n1ln t t dtnn 111ln td tn1n112 ,故由1n1求解得六个点：152,1, B A1 , , 21CD0,, E F由于在点A 与B 点处,u ；在点C与 D 处, u；在点E 与F 处, 0u ． 1 2 y y0 u n 0 ln n1 2 ,1根据夹逼定理得0 lim u n lim0 ,所以lim u n 0 .n n n1n2(19)【解析】(I) 因为2 f (0) 0 f x dx( ) ,又因为f x 在0,2上连续,所以由积分中值定理得,至少有一点0,2,使得20 f x dx f 20即2 f 0 2 f ,所以存在0,2,使得f f0 .f 2 f 3(Ⅱ)因为f 2 f 3 2 f 0 ,即 f 0 ,又因为f x 在2,3上连2续,由介值定理知,至少存在一点 1 2,3使得f 1 f 0 .因为f x 在0,2上连续,在0,2上可导,且f 0 f 2 ,所以由罗尔中值定数学(三)试题第15页 (共4页)微信公众号：考研研学姐答疑资讯QQ 群：451613025理知,Ｃ存在10,2,有f10. 又因为 f x 在2,1上连续,在2,1上可导,且f 2 ff1 ,所以由罗尔中值定理知,存在22,1,有 f20 . 又因为 fx在1,2上二阶可导,且f1f20 ,所以由罗尔中值定理,至少有一点 Ax b 0,3,使得f0 .(20) 【解析】因为方程组有两个不同的解,所以可以判断方程组增广矩阵的秩小于3,进而可以通过秩的关系求解方程组中未知参数,有以下两种方法.方法1：(I)已知Ax b 有2个不同的解,故r A ( ) r A ( ) 3 ,对增广矩阵进行初等行变换,得11 a 1 1 1A1 0 101 01 1 1 11 1a1 111 1 10 10 1 01010112a0 012a 11 1 1 11 111当1时,A0 00 10 01,此时,r A ( ) r A ( ),故Ax b 无解(舍00 0 a00 001 1 1 1微信公众号：考研研学姐答疑资讯QQ 群：451613025当1时, A 0 2 0 1 ,由于r A ( )0 0 0 a 2方法2：已知Axb 有2个不同的解,故r A ()r A () 3 ,因此 A 0,即11A0 10(1) (21)0 ,11知1或-1.当1时,r A () 1 r A () 2 ,此时,Ax b 无解,因此1.由r A () r A ( ) ,得a2.( II ) 对增广矩阵做初等行变换31121 11211 12A0 201 0 2 010 1 0121 1110 0000 0 003x x3x 1 1232微信公众号：考研研学姐答疑资讯QQ群：451613025x 21x 3 231 21因此Ax b的通解为x k 0 ,其中k为任意常数.10 10 1 4(21)【解析】由于A 1 3 a4 a 01 1微信公众号：考研研学姐答疑资讯QQ 群：45161302513 可知原方程组等价为2 ,写成向量的形式,即x 2x 0 1 .列为(1,2,1)T ,故 A 对应于1 的特征向量为1(1,2,1)T .12,即根据特征值和特征向量的定义,有A116141 3 a 41 1a2 12 ,由此可得a 1,12 .故A10 1 141 31 41.微信公众号：考研研学姐答疑资讯QQ 群：45161302514 由EA1 3 1 (4)( 2)(5) 0 ,41可得 A 的特征值为12,24, 35 . 4 由 (2E A x ) 0,即14特征向量为2(1,0,1)T .17 1 4x 11x 20 ,可解得对应于 24 的线性无关的4x 35 由 (3E A x )0 ,即 143(1,1,1)T .1 2 1 4x 11x 2 0 ,可解得对应于35 的特征向量为5 x 3由于 A 为实对称矩阵,1,2,3 为对应于不同特征值的特征向量,所以1,2,3相互正交,只需单位化：111(1,2,1) ,T2( 1,0,1) ,T3(1,1,1)T ,123163取,则Q T AQQ 1,2,351112微信公众号：考研研学姐答疑资讯QQ 群：451613025(22) 【解析】当给出二维正态随机变量的的概率密度 fx , y 后,要求条件概率密度f x y ( ,)f Y X | (y x | ) ,可以根据条件概率公式 f Y X | (y x | )来进行计算.本题中还有待定参 f X ( )x数, A 要根据概率密度的性质求解,具体方法如下.2 22 2 22x f x y dy, A e2x 2xy ydy A e(y x ) xdyf XAexe(y x )dyx 2A e ,x .根据概率密度性质有1f X x dx A ex2dxA,即 A1,1x 2故 f Xx e ,x. 当x时,有条件概率密度f x y ,Ae x 22xy y21x 2 2 21(x y )2 f YXy xf XxAex 2ee ,x ,y.(23)【解析】(I) X 的所有可能取值为 0,1 ,Y 的所有可能取值为 0,1,2 ．C 323 1,其中X 0,Y 0 表示取到的两个球都是黑球；P X0,Y2C 615 5P X 0,Y 1C C 21231 6 2,其中 X 0,Y 1表示取到的一个是白球,一个是C6 15 5黑球；C22 1 ,其中X 0,Y 2 表示取到的两个球都是白球；P X0,Y 22 C6 15P X 1,YC C112313 1,其中X 1,Y 0 表示取到的一个是红球,一个是C6 15 5黑球；P X 1,Y 1C C112212,其中X 1,Y 1表示取到的一个是红球,一个是白球；C6 15 0P X1,Y20 , C6因此二维离散型随机变量X ,Y 的概率分布为2 2 2 1 1E XY 1 1 ,E X0 1 ,I(I),C o v EXYXY EXEY,33 3E Y 012Cov X Y, E XYE X E Y.。

2010考研政治真题答案及详细解析(完整版)

2010年全国硕士研究生入学统一考试-政治试题一、单项选择题：1～16小题，每小题1分，共16分。

下列每题给出的四个选项中，只有一个选项是符合题目要求的。

请在答题卡上将所选项的字母涂黑。

1.1984年1月3日，意大利人卡内帕给恩格斯写信，请求他为即将在日内瓦出版的饿《新纪元》周刊的创刊号题词，而且要求尽量用简短的字句来表述未来的社会主义纪元的基本思想，以区别于伟大诗人但丁的对旧纪元所作的“一些人统治，另一些人受苦难”的界定。

恩格斯回答说，这就是：“代替那存在着阶级和阶级对立的资产阶级旧社会的，将是这样一个联合体，在那里，每个人的自由发展是一切人的自由发展的条件。

”这段话表明，马克思主义追求的根本价值目标是（）A．实现人的自由而全面的发展B．实现人类永恒不变的普适价值C．建立一个四海之内皆兄弟的大同世界D．建立一个自由，平等，博爱的理性王国2.有一则箴言：“在溪水和岩石的斗争中，胜利的总是溪水，不是因为力量，而是因为坚持。

”“坚持就是胜利”的哲理在于（）A．必然性通过偶然性开辟道路B．肯定中包含着否定的因素C．量变必然引起质变D．有其因必有其果3.右边这张照片反映出由于气候变暖，北极冰盖融化，致使北极熊无处可去的场景，颇具震撼力。

它给我们地球上的人类发出的警示是（）A．人与自然的关系成为人与人之间一切社会关系的核心B．生态失衡已成为自然界自身周期演化不可逆转的趋势C．自然地理环境已成为人类社会发展的根本决定力量D．生态环境已日益成为人类反思自身活动的重要前提4.劳动力成为商品是货币转化为资本的前提条件，这是因为（）A．资本家购买的是劳动力的价值B．劳动力商品具有价值和使用价值C．货币所有者购买的劳动力能够带来剩余价值D．劳动力自身的价值能够在消费过程中转移到新的商品中去5.1981年党的十一届六中全会通过《关于建国以来党的若干历史问题的建议》对我国社会主要矛盾作了规范的表述：“社会主义改造完成以后，我国所要解决的主要矛盾，是人民日益增长的物质文化需要同落后的社会生产之间的矛盾。

2010年全国硕士研究生入学考试英语(一)真题及答案

2010年全国硕士研究生招生考试英语一试题Section I Use of EnglishDirections:Read the following text. Choose the best word(s) for each numbered blank and nark A, B, C or D on ANSWER SHEET 1. (10 points)①In 1924 America’s National Research Council sent two engineers to supervise a series of experiments at a telephone-parts factory called the Hawthorne Plant near Chicago. ②It hoped they would learn how shop-ﬂoor lighting 1 workers’ productivity. ③Instead, the studies ended 2 giving their name to the “Hawthorne eﬀect,” the extremely inﬂuential idea that the very 3 of being experimented upon changed subjects’ behavior.①The idea arose because of the 4 behavior of the women in the plant. ②According to 5 of the experiments, their hourly output rose when lighting was increased, but also when it was dimmed. ③It did not 6 what was done in the experiment; 7 something was changed, productivity rose. ④A (n) 8 that they were being experimented upon seemed to be 9 to alter workers’ behavior 10 itself.①After several decades, the same data were 11 to econometric analysis. ②The Hawthorne experiments had another surprise in store. 12 the descriptions on record, no systematic 13 was found that levels of productivity were related to changes in lighting.①It turns out that peculiar way of conducting the experiments may have led to 14 interpretations of what happened. ② 15 , lighting was always changed on a Sunday. ③When work started again on Monday, output 16 rose compared with the previous Saturday and 17 to rise for the next couple of days. ④ 18 , a comparison with data for weeks when there was no experimentation showed that output always went up on Mondays. ⑤Workers 19 to be diligent for the ﬁrst few days of the week in any case, before 20 a plateau and then slackening oﬀ. ⑥This suggests that the alleged “Hawthorne eﬀect” is hard to pin down.1. [A] aﬀected [B] achieved [C] extracted [D] restored2. [A] at [B] up [C] with [D] oﬀ3. [A] truth [B] sight [C] act [D] proof4. [A] controversial [B] perplexing [C] mischievous [D] ambiguous5. [A] requirements [B] explanations [C] accounts [D] assessments6. [A] conclude [B] matter [C] indicate [D] work7. [A] as far as [B] for fear that [C] in case that [D] so long as8. [A] awareness [B] expectation [C] sentiment [D] illusion9. [A] suitable [B] excessive [C] enough [D] abundant10. [A] about [B] for [C] on [D] by11. [A] compared [B] shown [C] subjected [D] conveyed12. [A] Contrary to [B] Consistent with [C] Parallel with [D] Peculiar to13. [A] evidence [B] guidance [C] implication [D] source14. [A] disputable [B] enlightening [C] reliable [D] misleading15. [A] In contrast [B] For example [C] In consequence [D] As usual16. [A] duly [B] accidentally [C] unpredictably [D] suddenly17. [A] failed [B] ceased [C] started [D] continued18. [A] Therefore [B] Furthermore [C] However [D] Meanwhile19. [A] attempted [B] tended [C] chose [D] intended20. [A] breaking [B] climbing [C] surpassing [D]h i t t i n gSection Ⅱ Reading ComprehensionPart ADirections:Read the following four texts. Answer the questions below each text by choosing A, B, C or D. Mark your answers on ANSWER SHEET 1. (40 points)Text 1①Of all the changes that have taken place in English-language newspapers during the past quarter-century, perhaps the most far-reaching has been the inexorable decline in the scope and seriousness of their arts coverage.①It is diﬃcult to the point of impossibility for the average reader under the age of forty to imagine a time when high-quality arts criticism could be found in most big-city newspapers.②Yet a considerable number of the most signiﬁcant collections of criticism published in the 20th century consisted in large part of newspaper reviews. ③To read such books today is to marvel atthe fact that their learned contents were once deemed suitable for publication in general-circulation dailies.①We are even farther removed from the unfocused newspaper reviews published in England between the turn of the 20th century and the eve of World War II, at a time when newsprint was dirt-cheap and stylish arts criticism was considered an ornament to the publications in which it appeared. ②In those far-oﬀ days, it was taken for granted that the critics of major papers would write in detail and at length about the events they covered. ③Theirs was a serious business, and even those reviewers who wore their learning lightly, like George Bernard Shaw and Ernest Newman, could be trusted to know what they were about. ④These men believed in journalism as a calling, and were proud to be published in the daily press. ⑤“So few authors have brains enough or literary gift enough to keep their own end up in journalism,” Newman wrote, “that I am tempted to deﬁne ‘journalism’ as ‘a term of contempt applied by writers who are not read to writers who are’.”①Unfortunately, these critics are virtually forgotten. ②Neville Cardus, who wrote for the Manchester Guardian from 1917 until shortly before his death in 1975, is now known solely as a writer of essays on the game of cricket. ③During his lifetime, though, he was also one of England’s foremost classical-music critics, and a stylist so widely admired that his Autobiography (1947) became a best-seller. ④He was knighted in 1967, the ﬁrst music critic to be so honored. ⑤Yet only one of his books is now in print, and his vast body of writings on music is unknown save to specialists.①Is there any chance that Cardus’s criticism will enjoy a revival? ②The prospect seems remote. ③Journalistic tastes had changed long before his death, and postmodern readers have little use for the richly upholstered Vicwardian prose in which he specialized. ④Moreover, the amateur tradition in music criticism has been in headlong retreat.21. It is indicated in Paragraphs 1 and 2 that[A] arts criticism has disappeared from big-city newspapers[B] English-language newspapers used to carry more arts reviews[C] high-quality newspapers retain a large body of readers[D] young readers doubt the suitability of criticism on dailies22. Newspaper reviews in England before World War II were characterized by[A] free themes[B] casual style[C] elaborate layout[D] radical viewpoints23. Which of the following would Shaw and Newman most probably agree on?[A] It is writers’ duty to fulﬁll journalistic goals.[B] It is contemptible for writers to be journalists.[C] Writers are likely to be tempted into journalism.[D] Not all writers are capable of journalistic writing.24. What can be learned about Cardus according to the last two paragraphs?[A] His music criticism may not appeal to readers today.[B] His reputation as a music critic has long been in dispute.[C] His style caters largely to modern specialists.[D] His writings fail to follow the amateur tradition.25. What would be the best title for the text?[A] Newspapers of the Good Old Days[B] The Lost Horizon in Newspapers[C] Mournful Decline of Journalism[D] Prominent Critics in MemoryText 2①Over the past decade, thousands of patents have been granted for what are called business methods. ② received one for its “one-click” online payment system. ③Merrill Lynch got legal protection for an asset allocation strategy. ④One inventor patented a technique for lifting a box.①Now the nation’s top patent court appears completely ready to scale back on business-method patents, which have been controversial ever since they were first authorized 10 years ago. ②In a move that has intellectual-property lawyers abuzz, the U.S. Court of Appeals for the Federal Circuit said it would use a particular case to conduct a broad review of business-method patents. ③In re Bilski, as the case is known, is “a very big deal,” says Dennis D. Crouch of the University of Missouri School of Law. ④It “has the potential to eliminate an entire class of patents.”①Curbs on business-method claims would be a dramatic about-face, because it was the Federal Circuit itself that introduced such patents with its 1998 decision in the so-called State Street Bank case, approving a patent on a way of pooling mutual-fund assets. ②That ruling produced an explosion in business-method patent ﬁlings, initially by emerging Internet companies trying to stake out exclusive rights to specific types of online transactions. ③Later, more established companies raced to add such patents to their ﬁles, if only as a defensive move againstrivals that might beat them to the punch. ④In 2005, IBM noted in a court ﬁling that it had been issued more than 300 business-method patents, despite the fact that it questioned the legal basis for granting them. ⑤Similarly, some Wall Street investment ﬁrms armed themselves with patents for ﬁnancial products, even as they took positions in court cases opposing the practice.①The Bilski case involves a claimed patent on a method for hedging risk in the energy market. ②The Federal Circuit issued an unusual order stating that the case would be heard by all 12 of the court’s judges, rather than a typical panel of three, and that one issue it wants to evaluate is whether it should “reconsider” its State Street Bank ruling.①The Federal Circuit’s action comes in the wake of a series of recent decisions by the Supreme Court that has narrowed the scope of protections for patent holders. ②Last April, for example, the justices signaled that too many patents were being upheld for “inventions” that are obvious. ③The judges on the Federal Circuit are “reacting to the anti-patent trend at the Supreme Court,” says Harold C. Wegner, a patent attorney and professor at George Washington University Law School.26. Business-method patents have recently aroused concern because of[A] their limited value to businesses.[B] their connection with asset allocation.[C] the possible restriction on their granting.[D] the controversy over their authorization.27. Which of the following is true of the Bilski case?[A] Its ruling complies with the court decisions.[B] It involves a very big business transaction.[C] It has been dismissed by the Federal Circuit.[D] It may change the legal practices in the U.S.28. The word “about-face” (Para. 3) most probably means[A] loss of goodwill.[B] increase of hostility.[C] change of attitude.[D] enhancement of dignity.29. We learn from the last two paragraphs that business-method patents[A] are immune to legal challenges.[B] are often unnecessarily issued.[C] lower the esteem for patent holders.[D] increase the incidence of risks.30. Which of the following would be the subject of the text?[A] A looming threat to business-method patents.[B] Protection for business-method patent holders.[C] A legal case regarding business-method patents.[D] A prevailing trend against business-method patents.Text 3①In his book The Tipping Point, Malcolm Gladwell argues that “social epidemics” are driven in large part by the actions of a tiny minority of special individuals, often called inﬂuentials, who are unusually informed, persuasive, or well connected. ②The idea is intuitively compelling, but it doesn’t explain how ideas actually spread.①The supposed importance of influentials derives from a plausible-sounding but largely untested theory called the “two-step flow of communication” : Information flows from the media to the inﬂuentials and from them to everyone else. ②Marketers have embraced the two-step ﬂow because it suggests that if they can just ﬁnd and inﬂuence the inﬂuentials, those select people will do most of the work for them. ③The theory also seems to explain the sudden and unexpected popularity of certain looks, brands, or neighborhoods. ④In many such cases, a cursory search for causes ﬁnds that some small group of people was wearing, promoting, or developing whatever it is before anyone else paid attention. ⑤Anecdotal evidence of this kind ﬁts nicely with the idea that only certain special people can drive trends.①In their recent work, however, some researchers have come up with the finding that inﬂuentials have far less impact on social epidemics than is generally supposed. ②In fact, they don’t seem to be required at all.①The researchers’ argument stems from a simple observation about social inﬂuence: With the exception of a few celebrities like Oprah Winfrey—whose outsize presence is primarily a function of media, not interpersonal, inﬂuence—even the most inﬂuential members of a population simply don’t interact with that many others. ②Yet it is precisely these non-celebrity inﬂuentials who, according to the two-step-ﬂow theory, are supposed to drive social epidemics, by inﬂuencing their friends and colleagues directly. ③For a social epidemic to occur, however, each person so aﬀected must then inﬂuence his or her own acquaintances, who must in turn inﬂuence theirs, and so on; and just how many others pay attention to each of these people has little to do with the initial inﬂuential. ④If people in the network just two degrees removed from the initial inﬂuential prove resistant, for example, the cascade of change won’t propagate very far or affect many people.①Building on the basic truth about interpersonal influence, the researchers studied the dynamics of social influence by conducting thousands of computer simulations of populations, manipulating a number of variables relating to people’s ability to influence others and their tendency to be inﬂuenced. ②They found that the principal requirement for what is called “global cascades”—the widespread propagation of inﬂuence through networks—is the presence not of a few inﬂuentials but, rather, of a critical mass of easily inﬂuenced people.31. By citing the book The Tipping Point, the author intends to[A] analyze the consequences of social epidemics.[B] discuss inﬂuentials’ function in spreading ideas.[C] exemplify people’s intuitive response to social epidemics.[D] describe the essential characteristics of inﬂuentials.32. The author suggests that the “two-step-ﬂow theory”[A] serves as a solution to marketing problems.[B] has helped explain certain prevalent trends.[C] has won support from inﬂuentials.[D] requires solid evidence for its validity.33. What the researchers have observed recently shows that[A] the power of inﬂuence goes with social interactions.[B] interpersonal links can be enhanced through the media.[C] inﬂuentials have more channels to reach the public.[D] most celebrities enjoy wide media attention.34. The underlined phrase “these people” in Paragraph 4 refers to the ones who[A] stay outside the network of social inﬂuence.[B] have little contact with the source of inﬂuence.[C] are inﬂuenced and then inﬂuence others.[D] are inﬂuenced by the initial inﬂuential.35. What is the essential element in the dynamics of social inﬂuence?[A] The eagerness to be accepted.[B] The impulse to inﬂuence others.[C] The readiness to be inﬂuenced.[D] The inclination to rely on others.Text 4①Bankers have been blaming themselves for their troubles in public. ②Behind the scenes,they have been taking aim at someone else the accounting standard-setters. ③Their rules, moan the banks, have forced them to report enormous losses, and it’s just not fair. ④These rules say they must value some assets at the price a third party would pay, not the price managers and regulators would like them to fetch.①Unfortunately, banks’ lobbying now seems to be working. ②The details may be unknowable, but the independence of standard-setters, essential to the proper functioning of capital markets, is being compromised. ③And, unless banks carry toxic assets at prices that attract buyers, reviving the banking system will be diﬃcult. ④After a bruising encounter with Congress, America’s Financial Accounting Standards Board (FASB) rushed through rule changes. ⑤These gave banks more freedom to use models to value illiquid assets and more ﬂexibility in recognizing losses on long-term assets in their income statements. ⑥Bob Herz, the FASB’s chairman, cried out against those who question our motives. ⑦Yet bank shares rose and the changes enhance what one lobby group politely calls the use of judgment by management.①European ministers instantly demanded that the International Accounting Standards Board (IASB) do likewise. ②The IASB says it does not want to act without overall planning, but the pressure to fold when it completes it reconstruction of rules later this year is strong. ③Charlie McCreevy, a European commissioner, warned the IASB that it did not live in a political vacuum but in the real world and the Europe could yet develop diﬀerent rules.①It was banks that were on the wrong planet, with accounts that vastly overvalued assets.②Today they argue that market prices overstate losses, because they largely reﬂect the temporary illiquidity of markets, not the likely extent of bad debts. ③The truth will not be known for years.④But banks’ shares trade below their book value, suggesting that investors are skeptical.⑤And dead markets partly reflect the paralysis of banks which will not sell assets for fear of booking losses, yet are reluctant to buy all those supposed bargains.①To get the system working again, losses must be recognized and dealt with. ②America’s new plan to buy up toxic assets will not work unless banks mark assets to levels which buyers ﬁnd attractive. ③Successful markets require independent and even combative standard-setters. ④The FASB and IASB have been exactly that, cleaning up rules on stock options and pensions, for example, against hostility interests. ⑤But by giving in to critics now they are inviting pressure to make more concessions.36. Bankers complained that they were forced to[A] follow unfavorable asset evaluation rules.[B] collect payments from third parties.[C] cooperate with the price managers.[D] re-evaluate some of their assets.37. According to the author, the rule changes of the FASB may result in[A] the diminishing role of management.[B] the revival of the banking system.[C] the banks’ long-term asset losses.[D] the weakening of its independence.38. According to Paragraph 4, McCreevy objects to the IASB’s attempt to[A] keep away from political inﬂuences.[B] evade the pressure from their peers.[C] act on their own in rule-setting.[D] take gradual measures in reform.39. The author thinks the banks were “on the wrong planet” in that they[A] misinterpreted market price indicators.[B] exaggerated the real value of their assets.[C] neglected the likely existence of bad debts.[D] denied booking losses in their sale of assets.40. The author’s attitude towards standard-setters is one of[A] satisfaction.[B] skepticism.[C] objectiveness.[D] sympathy.Part BDirections:For questions 41-45, choose the most suitable paragraphs from the list A-G and ﬁll them into the numbered boxes to form a coherent text. Paragraph E has been correctly placed. There is one paragraph which does not ﬁt in with the text. Mark your answers on ANSWER SHEET1. (10 points)[A] The first and more important is the consumer’s growing preference for eating out; theconsumption of food and drink in places other than homes has risen from about 32 percent of total consumption in 1995 to 35 percent in 2000 and is expected to approach 38 percent by 2005. This development is boosting wholesale demand from the food service segment by 4 to 5 percent a year across Europe, compared with growth in retail demand of 1 to 2 percent.Meanwhile, as the recession is looming large, people are getting anxious. They tend to keep atighter hold on their purse and consider eating at home a realistic alternative.[B] Retail sales of food and drink in Europe’s largest markets are at a standstill, leaving Europeangrocery retailers hungry for opportunities to grow. Most leading retailers have already tried e-commerce, with limited success, and expansion abroad. But almost all have ignored the big, proﬁtable opportunity in their own backyard: the wholesale food and drink trade, which appears to be just the kind of market retailers need.[C] Will such variations bring about a change in the overall structure of the food and drink market?Definitely not. The functioning of the market is based on flexible trends dominated by potential buyers. In other words, it is up to the buyer, rather than the seller, to decide what to buy. At any rate, this change will ultimately be acclaimed by an ever-growing number of both domestic and international consumers, regardless of how long the current consumer pattern will take hold.[D] All in all, this clearly seems to be a market in which big retailers could proﬁtably apply theirgigantic scale, existing infrastructure, and proven skills in the management of product ranges, logistics, and marketing intelligence. Retailers that master the intricacies of wholesaling in Europe may well expect to rake in substantial proﬁts thereby. At least, that is how it looks as a whole. Closer inspection reveals important differences among the biggest national markets, especially in their customer segments and wholesale structures, as well as the competitive dynamics of individual food and drink categories. Big retailers must understand these differences before they can identify the segments of European wholesaling in which their particular abilities might unseat smaller but entrenched competitors. New skills and unfamiliar business models are needed too.[E] Despite variations in detail, wholesale markets in the countries that have been closely examined—France, Germany, Italy, and Spain—are made out of the same building blocks. Demand comes mainly from two sources: independent mom-and-pop grocery stores which, unlike large retail chains, are too small to buy straight from producers, and food service operators that cater to consumers when they don’t eat at home. Such food service operators range from snack machines to large institutional catering ventures, but most of these businesses are known in the trade as “horeca”: hotels, restaurants, and cafés. Overall, Europe’s wholesale market for food and drink is growing at the same sluggish pace as the retail market, but the ﬁgures, when added together, mask two opposing trends.[F] For example, wholesale food and drink sales came to $268 billion in France, Germany, Italy,Spain, and the United Kingdom in 2000—more than 40 percent of retail sales. Moreover, average overall margins are higher in wholesale than in retail; wholesale demand from thefood service sector is growing quickly as more Europeans eat out more often; and changes in the competitive dynamics of this fragmented industry are at last making it feasible for wholesalers to consolidate.[G] However, none of these requirements should deter large retailers (and even some largefood producers and existing wholesalers) from trying their hand, for those that master the intricacies of wholesaling in Europe stand to reap considerable gains.41. →42. →43. →44. →E →45.Part CDirections:Read the following text carefully and then translate the underlined segments into Chinese. Your translation should be written clearly on ANSWER SHEET 2. (10 points)One basic weakness in a conservation system based wholly on economic motives is that most members of the land community have no economic value. Yet these creatures are members of the biotic community and, if its stability depends on its integrity, they are entitled to continuance.When one of these noneconomic categories is threatened and, if we happen to love it, we invent excuses to give it economic importance. At the beginning of the century songbirds were supposed to be disappearing. (46) Scientists jumped to the rescue with some distinctly shaky evidence to the eﬀect that insects would eat us up if birds failed to control them. The evidence had to be economic in order to be valid.It is painful to read these roundabout accounts today. We have no land ethic yet, (47) but we have at least drawn nearer the point of admitting that birds should continue as a matter of intrinsic right, regardless of the presence or absence of economic advantage to us.A parallel situation exists in respect of predatory mammals and ﬁsh-eating birds. (48) Time was when biologists somewhat overworked the evidence that these creatures preserve the health of game by killing the physically weak, or that they prey only on “worthless” species. Here again, the evidence had to be economic in order to be valid. It is only in recent years that we hear the more honest argument that predators are members of the community, and that no special interest has the right to exterminate them for the sake of a beneﬁt, real or fancied, to itself.Some species of trees have been “read out of the party” by economics-minded foresters because they grow too slowly, or have too low a sale value to pay as timber crops. (49) In Europe, where forestry is ecologically more advanced, the noncommercial tree species are recognized as members of the native forest community, to be preserved as such, within reason. Moreover, somehave been found to have a valuable function in building up soil fertility. The interdependence of the forest and its constituent tree species, ground ﬂora, and fauna is taken for granted.To sum up: a system of conservation based solely on economic self-interest is hopelessly lopsided. (50) It tends to ignore, and thus eventually to eliminate, many elements in the land community that lack commercial value, but that are essential to its healthy functioning. It assumes, falsely, that the economic parts of the biotic clock will function without the uneconomic parts.Section Ⅲ WritingPart A51. Directions:You are supposed to write for the Postgraduates’ Association a notice to recruit volunteers for an international conference on globalization. The notice should include the basic qualiﬁcations for applicants and the other information which you think is relevant.You should write about 100 words on ANSWER SHEET 2.Do not sign your own name at the end of the notice. Use “Postgraduates’ Association”instead. (10 points)Part B52. Directions:Write an essay of 160-200 words based on the following drawing. In your essay, you should1) describe the drawing brieﬂy,2) explain its intended meaning, and3) give your comments.You should write neatly on ANSHWER SHEET 2. (20 points)2010年英语（一）试题参考答案Section I Use of English1. A. aﬀected2. B. up3. C. act4. B. perplexing5. C. accounts6. B. matter7. D. so long as8. A. awareness9. C. enough10. D. by11. C. subjected12. A. Contrary to13. A. evidence14. D. misleading15. B. For example16. A. duly17. D. continued18. C. However19. B. tended20. D. hittingSection Ⅱ Reading Comprehension Part AText121. B. English-language newspapers used to carry more arts reviews.22. A. free themes.23. D. Not all writers are capable of journalistic writing.24. A. His music criticism may not appeal to readers today.25. B. The Lost Horizon in NewspapersText226. C. the possible restriction on their granting.27. D. It may change the legal practices in the U.S.28. C. change of attitude.29. B. are often unnecessarily issued.30. A. A looming threat to business-method patents.Text331. B. discuss inﬂuentials’ function in spreading ideas.32. D. requires solid evidence for its validity.33. A. the power of inﬂuence goes with social interactions.34. C. are inﬂuenced and then inﬂuence others.35. C. The readiness to be inﬂuenced.Text436. A. follow unfavorable asset evaluation rules.37. D. the weakening of its independence.38. C. act on their own in rule-setting.39. B. exaggerated the real value of their assets.40. D. sympathy.Part B41. B. Retail sales of food and drink in Europe’s largest markets are at a standstill, leaving European grocery retailers hungry for opportunities to grow. Most leading retailers have already tried e-commerce, with limited success, and expansion abroad. But almost all have ignored the big, proﬁtable opportunity in their own backyard: the wholesale food and drink trade, which appears to be just the kind of market retailers need.42. F. For example, wholesale food and drink sales came to $268 billion in France, Germany, Italy, Spain, and the United Kingdom in 2000—more than 40 percent of retail sales. Moreover, average overall margins are higher in wholesale than in retail; wholesale demand from the food service sector is growing quickly as more Europeans eat out more often; and changes in the competitive dynamics of this fragmented industry are at last making it feasible for wholesalers to。

2010年硕士研究生入学考试试题A答案

华北电力大学（8 无机化学
考生注意：全部答案（包括填空、选择、判断对错等）必须写在答题纸上，否则无效。
卷别： A
一、填空（每空 0.5 分，共 25 分）
1． Cu+在水溶液中不稳定，容易歧化为__ Cu___和_ Cu2 ___，反应方程式为_2Cu+_ ___ ＋ Cu __＋__ Cu2 _________。 2．在 300ml 0.2mol/L 的氨水中，加入 900ml 的水，氨水的 pH 为__11___，电离度为__1.87％ -5 （NH3· H2O Kb=1.75× 10 ） 3．实验测定，2H 2+2NO N2 + 2H2O 的反应机理是：（1）2NO + H2 N2(g) + H2O2 (慢步骤) （2）H2O2+ H2 2 H2O （快步骤）则该反应是__非基元______（基元或非基元）反应，速率方程式是_V=kC（NO）C（H2） __ 反应总级数是__________3_______。 4．反应 CO2 (g)+ C(固) 2CO(g)是熵___增____反应，升高温度，正反应速率___升高 ____，逆反应速率__升高__，若此时平衡向正反应方向移动，那么生成 CO 的反应是__吸热___（放热或吸热）反应，降低__（增加或降低）总压强，可使平衡向正反应方向移动。 2 5．已知 SO2 的杂化方式为不等性 sp 杂化，则其几何构型为_角型_______，是____极性___(极性－－或非极性)分子；而 SO42 的几何构型为正四面体，则 S 的杂化方式为___ sp3______，SO42 中除了 S 和 O 原子之间的____σ _____（σ 或π ）键外，还存在 p-dπ 键。 6．某元素原子主量子数 n 为 4 的电子层上有 7 个电子，该原子的价层电子构型为 4s245 ，该元素原子序数为 35 ，它位于第四周期，元素符号为 Br，第七主族族， P 区。 7．配合物二氯化一氯· 五氨合钴（Ⅲ）的分子式为 [CoCl(NH3)5]Cl2 ，中心离子（形成－ 3+ 体）是 Co ，配位体是 Cl 和氨分子，中心离子的配位数是 6 ，如果此配合 2 3 物为内轨构型，则此配合物的磁矩是 0 中心离子杂化方式为___d sp ____，配离子＋－的空间构型为__八面体_____，Kf(稳)表达式为_C([CoCl(NH3)]2 /（Co3+）× C(Cl )C(NH3)5_。 8．石英的硬度比干冰___大____，其原因是石英是原子晶体____，CaO 的熔点比 MgO__低___，其原因是__钙离子的半径大，晶格能低___，石墨能够在沿层的方向上导电，但在垂直于层的方向上是绝缘的，原因是__石墨层内有_大 π 键__，乙硼烷的化学性质非常活泼，与水和空气剧烈反应，原因是____乙硼烷中有氢桥键______________________。 9、 H2S，AsH3，BiH3 的沸点由高到低的顺序为 BiH3 、 AsH3，、 H2S，，它们的分子间作用力有色散力、诱导力、取向力，浓硫酸是一种粘稠状液体，原因是有氢键存在。 10、实验室配制 SnCl2 溶液时，应先把 SnCl2 溶解于浓盐酸中，再稀释到相应浓度。

2010年考研数一试题及答案

2010年全国硕士研究生入学统一考试数学（一）试题及参考答案一、选择题：1~8小题，每小题4分，共32分。

1、222ln 1()()()()lim lime lime()()xx x xx x a x b x a x b x x x xx a x b ⎛⎫⎛⎫-⎪ ⎪ ⎪ ⎪-+-+⎝⎭⎝⎭→∞→∞→∞⎛⎫==⎪-+⎝⎭()()2()()()()lim elim e a b x ab a b x abxx x a x b x a x b x x -+⎛⎫-+ ⎪ ⎪-+-+⎝⎭→∞→∞==e a b -=方法二22()()lim lim 1()()()()xxx x x x x a x b x a x b x a x b →∞→∞⎛⎫⎛⎫--+=+ ⎪ ⎪-+-+⎝⎭⎝⎭()()()()()()()()lim 1lim 1()()()()x a x b a b x abxxa b x ab x a x b x x a b x ab a b x ab x a x b x a x b -+-+⋅-+-+→∞→∞⎛⎫⎛⎫-+-+=+=+ ⎪ ⎪-+-+⎝⎭⎝⎭()lim()()()ee x a b x abxa b x a x b →∞-+--+==（2）等式两边求全微分得：12d d 0y z F F x x ⎛⎫⎛⎫''⋅+⋅= ⎪ ⎪⎝⎭⎝⎭，即 1222d d dz d 0x y y x x z xF F x x --''+=12(d d )(dz d )0F x y y x F x z x ''⇒⋅-+⋅-= 12122dz d d yF zF F x y xF F '''+∴=-'' 所以有，1212222yF zF F zF z z xy x y z u y xF F F ''''+∂∂+=-==∂∂'''（3）、【解析与点评】：显然0,1x x ==是两个瑕点，有=+⎰对于的瑕点0x =，当0x +→21ln (1)mnx x -=-等价于221(1)mm nx--，而21120m nxdx -⎰收敛（因,m n 是正整数211m n⇒->-），故收敛；对于的瑕点1x =，当1(1,1)(0)2x δδ∈-<<12122ln (1)2(1)n m n mx x <-<-，而2112(1)m x dx -⎰显然收敛，故收敛。

【数学二】2010年全国考研研究生入学考试真题及答案答案解析

2010年全国硕士研究生入学统一考试数学二试题一、选择题(1~8小题,每小题4分,共32分.下列每题给出的四个选项中,只有一个选项符合题目要求的,请将所选项前的字母填在答题纸．．．指定位置上.) (1) 函数()f x =( ) (A) 0. (B) 1. (C) 2. (D) 3.(2) 设12,y y 是一阶线性非齐次微分方程()()y p x y q x '+=的两个特解,若常数λμ，使12y y λμ+是该方程的解,12y y λμ-是该方程对应的齐次方程的解,则( ) (A) 11,22λμ==. (B) 11,22λμ=-=-. (C) 21,33λμ==. (D) 22,33λμ==. (3) 曲线2y x =与曲线ln (0)y a x a =≠相切,则a = ( )(A) 4e. (B) 3e. (C) 2e. (D) e.(4) 设,m n 是正整数,则反常积分⎰的收敛性 ( )(A) 仅与m 的取值有关. (B) 仅与n 的取值有关.(C) 与,m n 取值都有关. (D) 与,m n 取值都无关.(5)设函数(,)z z x y =,由方程(,)0y zF x x=确定,其中F 为可微函数,且20F '≠,则z z x y x y∂∂+=∂∂( ) (A) x . (B) z . (C) x -. (D) z -.(6) ()()2211lim n nn i j n n i n j →∞===++∑∑ ( ) (A) ()()1200111x dx dy x y ++⎰⎰. (B) ()()100111x dx dy x y ++⎰⎰. (C) ()()1100111dx dy x y ++⎰⎰. (D) ()()11200111dx dy x y ++⎰⎰. (7) 设向量组12I :,,,r ααα可由向量组12II :,,,s βββ线性表示,下列命题正确的是( )(A) 若向量组I 线性无关,则r s ≤. (B) 若向量组I 线性相关,则r s >.(C) 若向量组II 线性无关,则r s ≤. (D) 若向量组II 线性相关,则r s >.(8) 设A 为4阶实对称矩阵,且2A A O +=,若A 的秩为3,则A 相似于 ( ) (A) 1110⎛⎫ ⎪ ⎪ ⎪ ⎪⎝⎭. (B) 1110⎛⎫ ⎪ ⎪ ⎪- ⎪⎝⎭. (C) 1110⎛⎫ ⎪- ⎪ ⎪- ⎪⎝⎭. (D) 1110-⎛⎫ ⎪- ⎪ ⎪- ⎪⎝⎭. 二、填空题(9~14小题,每小题4分,共24分.请将答案写在答题纸．．．指定位置上.) (9) 3阶常系数线性齐次微分方程220y y y y ''''''-+-=的通解为y = .(10) 曲线3221x y x =+的渐近线方程为 . (11) 函数()ln 120y x x =-=在处的n 阶导数()()0n y = . (12) 当0θπ≤≤时,对数螺线r e θ=的弧长为 .(13) 已知一个长方形的长l 以2cm/s 的速率增加,宽w 以3cm/s 的速率增加.则当cm 12l = ,cm 5w =时,它的对角线增加的速率为 .(14)设,A B 为3阶矩阵,且132,2A B A B -==+=，,则1A B -+= .三、解答题(15~23小题,共94分.请将解答写在答题纸．．．指定位置上.解答应写出文字说明、证明过程或演算步骤.)(15)(本题满分11分)求函数2221()()x t f x x t e d -=-⎰的单调区间与极值.(16)(本题满分10分) ( I ) 比较()10ln ln 1n t t dt +⎡⎤⎣⎦⎰与10ln n t t dt ⎰()1,2,n =的大小,说明理由；( II ) 记()10ln ln 1n n u t t dt =+⎡⎤⎣⎦⎰()1,2,n =,求极限lim n n u →∞. (17)(本题满分10分)设函数()y f x =由参数方程22,(1)()x t t t y t ψ⎧=+>-⎨=⎩所确定,其中()t ψ具有2阶导数,且5(1)(1) 6.2ψψ'==，已知223,4(1)d y dx t =+求函数()t ψ. (18)(本题满分10分)一个高为l 的柱体形贮油罐,底面是长轴为2a ,短轴为2b 的椭圆.现将贮油罐平放,当油罐中油面高度为32b 时(如图),计算油的质量.(长度单位为m,质量单位为kg,油的密度为常数ρkg/m 3) (19) (本题满分11分)设函数(,)u f x y =具有二阶连续偏导数,且满足等式2222241250u u u x x y y∂∂∂++=∂∂∂∂,确定a ,b 的值,使等式在变换,x ay x by ξη=+=+下化简为20u ξη∂=∂∂. (20)(本题满分10分)计算二重积分2 sin D I r θ=⎰⎰,其中(),|0sec ,04D r r πθθθ⎧⎫=≤≤≤≤⎨⎬⎩⎭. (21) (本题满分10分)设函数()f x 在闭区间[]0,1上连续,在开区间()0,1内可导,且(0)0f =,1(1)3f =,证明：存在1(0,)2ξ∈,1(,1)2η∈,使得22()()=.f f ξηξη''++(22)(本题满分11分) 设110111a A b λλλ ⎛⎫⎛⎫ ⎪ ⎪= - 0= ⎪ ⎪ ⎪ ⎪1 1 ⎝⎭⎝⎭，,已知线性方程组Ax b =存在两个不同的解．( I ) 求λ,a ;( II ) 求方程组Ax b =的通解.(23)(本题满分11 分)设0141340A a a -⎛⎫ ⎪=- ⎪ ⎪⎝⎭,正交矩阵Q 使得T Q AQ 为对角矩阵,若Q 的第1列为2,1)T ,求,a Q .。

2010管理类联考综合真题(含答案)

4
(E）古典音乐不流行。如果流行，那就说明大众的音乐欣赏水平大大提高了。 32. 在某次课程教学改革研讨会上，负责工程类教学的程老师说，在工程设计中，用于解决数学问题的计算机程序越来越多了，这样就不必要求工程技术类大学生对基础数学有深刻的理解．因此，在未来的教学中，基础数学课程可以用其它重要的工程类课程代替。以下哪项如果为真，能削弱程老师的上述论证？ I，工程类基础课程中已经包含了相关的基础数学的内容。 II，在工程设计中，设计计算机程序需要对基础数学有全面的理解。田，基础数学课程的一个重要目标是培养学生的思维能力，这种能力对工程设计来说很关键。 (A）只有E (D）只有E和皿 (B）只有I和E (E) I、 II和III (C) I、 II和皿
2 2
A
D
c
图3
三、逻辑推理z第26-55小题，每小题2分，共60分。下列每题所给出的（A)、（B）、（C）、（D）、（E）五个选项中，只有－项是符合试题要求的．请在答题卡上将所选项的字母涂黑． 26.针对威胁人类健康的甲型HlNl流感，研究人员研制出了相应的疫苗，尽管这些疫苗是有效的，但某大学研究人员发现，阿司匹林、提苯基乙酷肢等抑制某些酶的药物会影响疫苗的效果，这位研究员指出：如果你服用了阿司匹林或者乙酷基酌，那么你注射疫苗后就必然不会产生良好的抗体反映。” 如果小张住射疫苗后产生了良好的抗体反映，那么根据上述研究结果可以得出一下哪些结论？ (A）小张服用了阿司匹林，但没有服用对乙酷基盼。 (B）小张服没有用阿司匹林，但感染了HlNl流感病毒。 (C）小张服用了阿司匹林，但没有感染了HlNl流感病毒。 (D）小张服没有用了阿司匹林，也没有服用对乙酷基醋。 (E）小张服用了乙酷基盼，但没有服用担苯基乙酷肢。 27.为了调查当前人们的识字水平，其实验者列举了20个词语，请30位文化人士识读，这些人的文化程度都在大 “ 专以上。识读结果显示，多数人具读对3到5个词语，极少数人读对15以上，甚至有人全部读错。其中，蹒 ” ” 跚的辨识率最高，30人中有19人读对，“呱呱坠地所有人都读错，20个词语的整体误读率接近80%，该实验者由此得出，当前人们的识字水平并没有提高，甚至有所下降。以下哪项如果是真，最能对该实验者的结论构成质疑？

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率及每台发电机发出的功率是多少？ 28、某4 节点电力系统如下：
（1）写出节点导纳矩阵 Y （2）如果节点 1 和节点 2 之间的支路改成如下所示的变压器支路，其变比 1.04:1。即
写出节点导纳矩阵 Y
'
（3）若节点 2 和节点 4 之间连接一条支路，那么（1）中节点导纳矩阵中那些元素变化？（4）如果节点 1 是平衡节点， V1
18、电力系统频率发生变化时，主要依靠调节（_____）来达到调整频率的目的，或者说电力系统中该类型的功率对频率敏感。 19、电力系统电压发生变化时，主要依靠调节（_____）来达到调整电压的目的，或者说电力系统中该类型的功率对电压敏感。 20、（_____）对电力系统有很重要的意义，它是安排日发电计划，确定各发电厂发电任务以及确定系统运行方式等的重要依据。把每天的最大负荷抽取出来按年绘成曲线，成为（_____）该曲线作为被安排各发电厂检修计划以及安排新装机组计划的依据。 21、电压损耗是指电力网任意两点电压的（_____），近似等于电压降落的纵分量。电压偏移是指网络中某点的实际电压有效值与相应线路（_____）的差值。 22、在电力系统计算中，所采用的参数和变量有单位时的计算方法称为（_____），所采用的参数和变量无单位时的计算方法称为（_____）。
12、由发电机组的调频器完成，使发电机组的静态特性平行上移，以保证频率偏差在允许范围内是指电力系统的（）。 A.一次调频 B.二次调频 C.三次调频 D.两次调频
13、电力系统短路故障发生几率最大的是（）。 A.三相短路 B.单相接地短路 C.两相短路 D.两相接地短路
14、无限大功率电源供电系统发生突然三相短路时，短路电流将出现（）分量。 A.交流分量 B.直流分量 C.高频分量 D.零序分量
华北电力大学（北京）2010 年硕士研究生入学考试试题
考试科目：《电力系统分析基础一》考生注意：答案必须写在答题纸上试题内容：
一、不定项选择题（每题 1 分，共 15 分）
1、下列关于电力系统运行的特点中，正确的是（） A.电能不能大量存储 C.过渡过程比较慢 2、衡量电能质量的主要指标有（） A.电压 B.电流 C.频率 D.波形 B.输配电各环节可以分割 D.电力系统地区性特点不强
10、当电力系统无功电源不足时，调压措施中不能采用的哪一种方式（） A.改变发电机的励磁调压 B.改变变压器变比 C.改变电力网的无功功率分布 D.改变输电线路参数 11、按各机组耗量微增率相等的原则分配发电机发电功率，称为（）。 A.等面积定则 B.等比耗量定则 C.等微增率定则 D.合理分配方案
X Gf
、 X sf 。
X Gjs
G 0.2''
（4）如果根据运算曲线查得 t=0.2 秒时电源 G 的短路电流标幺值为 I 点总电流的有名值是多少？
2.6 ，则
t=0.2 秒时短路
27、两台额定容量为 54MW、额定频率为 50HZ 的发电机共同承担负荷，它们的调差系数分别为 4.5% 和 3.6%，若它们空载并列运行，其频率为 50HZ，求：两台发电机共同承担 90MW 负荷时，系统频
3、架空线路主要由（）等部件组成。 A.导线 B.避雷线 C.绝缘子 D.金具 E.杆塔
4、（）的目的是消除由于位置原因引起的不对称电抗，从而消除产生的电流畸变。 A.架空线路换位 B.分裂导线 C.采用电缆送电 D.提高电压等级
5、电压降落是指（） A.电力网中任意两点之间角度差 B.电力网中任意两点电压的相量差 C.电力网中任意两点电压有效值之差
l
30、某系统接线图如图所示，各元件标幺参数（SB =100MVA ，UB=U av ）已标于图中，当 f 点发生 A 相接地短路时，试求发电机 G 送出的各相电流有名值（设系统短路前空载， Uf 0=1.0 ）。
7、在潮流计算的计算机算法中，一般将节点划分为 PV 节点，（）和平衡节点 3 种类型。 A.PH 节点 B.Vθ 节点 C.PQ 节点 D.参考节点
8、电力系统备用容量，根据满足的需求不同分为一下几种：（） A.负荷备用 B.事故备用 C：常调压、（）和逆调压。 A.正调压 B.负调压 C.顺调压 D.反调压
三、简答和简单计算题（共 40 分）
23、试比较中性点直接接地和中性点不接地电力系统的优缺点，并说明它们各自的适用范围。 24、一条阻抗 z=r+jx 的输电线路，末端带感性负荷 S=P+jQ，作该线路的电压向量图，并在向量图中 25、试比较和分析牛顿法和 PQ 分解法的差别以及联系。 26、某系统接线及元件参数如图所示，设在 f 点发生三相短路，发电机容量为 40MVA，UB=Uav（即变压器变比区平均额定变比），试计算：（1）作出系统等值电路。（2）电源 G 及系统 S 对 f 点的转移电抗（3）电源 G 的计算电抗
15、影响变压器零序电抗参数的主要因素有（）。 A.铁芯结构 B.绕组联接方式 C.中性点接地方式 D.外电路联接方式
二、填空题（每空 1 分，共 15 分）
16、电力系统节点导纳矩阵和节点阻抗矩阵的关系是（_____）。N 节点网络，节点导纳矩阵是（_____）阶的。节点导纳矩阵具有（_____）和（_____）的特点，而节点阻抗矩阵是（_____），因此为了节省存储空间，常用节点导纳矩阵而不采用节点阻抗矩阵来存储网络参数。 17、电压用直角坐标描述时，潮流方程为_____,电压用极坐标描述时，潮流方程为_____.
D.网络中某点的实际电压有效值与相应线路标称电压的差值 6、要求某台电力变压器接入的电压等级为 220V、 110kV 和 10kV，对其作为升压变压器时的三侧额定电压为（）。 A.242/121/10.5kV B.230/115/10.5kV C.220/121/11kV D.242/121/10kV
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1, 1 0 。节点 2 是 PV 节点， V2 和 P2 已知，节点 3 和节点 4
均为 PQ 节点，列写极坐标形式下，采用牛顿法求解的潮流方程，并列写雅克比矩阵中的元素：
P4 P4 P4 的表达式。 , , V4 3 4
29、额定电压 220kV，长度 200km 的单回输电线路，已知线路末端负荷 S U =210kV ，如图所示。线路参数为： r =0.15Ω/km ， x =0.45Ω/km ， l b 2 路始端电压和功率。，电压 -6S/km l 。试计算线