【北京科技大学2012年考研专业课真题】传热学2012

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【北京科技大学2012年考研专业课真题】单独考试数学2012

北京科技大学2012年硕士学位研究生入学考试试题============================================================================================================= 试题编号： 610 试题名称：单独考试数学（共3 页）适用专业：全校各专业单独考试考生说明：所有答案必须写在答题纸上，做在试题或草稿纸上无效。

=============================================================================================================一、单项选择题（本题8小题，每题4分，满分32） 1. =⎪⎭⎫ ⎝⎛⎰⎰--→2020022lim x t x t x dt te dt e （）（A ）０．（B ）１. （C ）２．（D ）∞．2. 设)(x f 在),(+∞-∞内由定义, 则下列函数中必为奇函数的是（A ）)(x f y =．（B ）)(x f y -= ．（C ）．)(x f y = （D ）)(2x xf y =． 3. 函数⎪⎩⎪⎨⎧≤<-≤<-=312101)(x x x x x f 在1=x 处间断是因为（）(A ) )(x f 在1=x 处无定义． (B ))(lim 1x f x -→不存在． (C ) )(lim 1x f x +→不存在． (D ) )(lim 1x f x →不存在. 4. ∑是)(2122y x z +=介于0=z 及2=z 之间的下侧, 则⎰⎰∑-+zdxdy dydz x z )(2=（）（A ）π．（B ）π2．（C ）π4．（D ）π8．5. 设幂级数∑∞=1n n n x a 的收敛半径为R )0(+∞<<x ，则∑∞=⎪⎭⎫ ⎝⎛13n nn x a 的收敛半径为（）（A ）3R ．（B ）R3．（C ）R ．（D ）R 3．6. 设L 是由直线1,0==x y 及1=+y x 所围成的三角形的正向边界，则曲线积分⎰=-L ydx xdy 3( )（A ）1．（B ）2．（C ）3．（D ）4．7. 设x x f tan ln )(=, 则=')(x f （）(A ) x tan 1． (B ) x 2sin 2． (C )-22tan x ． (D ) x x 2sin cos ．. 8. 设D 是圆域422≤+y x , 则=+⎰⎰dxdy y x D 22（）(A ) 38π． (B )316π． (C ) 4π． (D ) π. 二、填空题（本题6小题，每题4分，满分24）9. 设⎰+=3241)(x x t dt x P ，则=')1(P _____．10. )(x f y =由方程03275=--+x x y y 所确定，则曲线)(x f y =在点)0,0(处的切线斜率k =_____． 11.⎰=++3011dx xx _____． 12.=+⎰⎰102arcsin 2cos 1cos dx x x dy y π _____． 13.=⎰+1012dx e x _____． 14.⎰=dx x x 2cos 2sin _____．三、计算题（本题7小题，每题10分，满分70）15. 求4212+-=x x y 极值和拐点． 16. 设)ln(yzz x =，求dz ． 17. 判定交错级数∑∞=-+-1)1()1(n n n n 的．18. 求由方程0)ln(22=+-xyz xyz xz 所确定的隐函数),(y x z z =在点(1,1)处的全微分．19. 设⎰>+=xx dt t t x f 10,1ln )(，求)1()(xf x f +． 20. 求⎰+dx xx 32)1ln(． 21. 已知)(x g 具有二阶连续导数，且1)0(=g ，又函数⎪⎩⎪⎨⎧=≠-=0,0,c o s )()(x a x x x x g x f确定a 的值使)(x f 在0=x 处连续；(2)求)(x f '；（３）讨论)(x f '在0=x 的连续性．四、应用证明题（本题2小题，每题12分，满分24） 22. 求曲线xy 1=与直线2,4==x x y 围成区域的面积S 绕x 轴旋转所成的旋转体的体积V ．23. 证明：当0>x 时，1)1ln(+<+x xx ．.。

北京科技大学安全原理2012年考研专业课初试真题

北京科技大学2012年硕士学位研究生入学考试试题================================================================================================= ============试题编号： 847 试题名称：安全原理（共 4 页）适用专业：安全科学与工程说明：所有答案必须写在答题纸上，做在试题或草稿纸上无效。

================================================================================================= ============一、名词解释（每题2分，共10分）1　风险：2　可承受风险：3　危害辩识：4　系统安全：5　职业安全健康管理体系：二、填空题（每题3分，共30分）1、目前，我国矿山安全避险“六大系统”包括：。

2、重伤指损失工作日为工作日以上，个工作日以下的失能伤害。

3、重大事故：是指一次造成人以上人以下死亡；或者人以上人以下重伤；或者万元以上亿元以下直接经济损失的事故。

4、事故调查的原则：。

5、安全生产责任追究是指对安全生产责任者未履行安全生产有关的法定责任，根据其行为的性质及后果的严重性，追究其责任的一种制度。

6、职业病是指企业、事业单位和个体经济组织的劳动者在职业活动中，因接触等因素而引起的疾病。

7、我国劳动法第五章第53条规定的劳动安全卫生设施必须符合国家规定的标准，并要求遵循“四同时”原则，即，“新建、改建、扩建工程的劳动安全卫生设施必须与主体工程。

”8、根据国务院第493号令《生产安全事故报告和调查处理条例》和国务院第302号令《国务院关于特大安全事故行政责任追究的规定》的规定：事故调查和处理必须采取“四不放过”原则。

9、安全信息类型分为一次安全信息和二次安全信息。

一次安全信息是指生产过程中的；二次安全信息包括等。

【北京科技大学2012年考研专业课真题】微生物学B2012

北京科技大学2012年硕士学位研究生入学考试试题======================================================================== =====================================试题编号：823 试题名称：微生物学B （共4 页）适用专业：生物化学与分子生物学说明：所有答案必须写在答题纸上，做在试题或草稿纸上无效。

======================================================================== =====================================一、名词解释（20分，每题2分）1. L型细菌：2. 启动子：3. 转座因子：4. 芽孢（内生孢子）：5. 真核微生物细胞的主要特征：6. 缩短微生物生长延迟期的方法：7. 病毒侵染细胞受体：8. 紫膜光合磷酸化：9. PCR的英文全称及反应步骤：10. 特异性免疫（获得性免疫）：二、填空题（30分，每空0.5分）1. 微生物包括：细胞结构不能独立生活的、；具原核细胞结构的和；具真核细胞结构的、和等。

1977年伍斯（Woese）利用建立分子进化树将生物分为3个域分别是、和。

2. 革兰氏阳性细菌细胞壁的主要成分为和，而革兰氏阴性细菌细胞壁的主要成分则是，，和。

3. 微生物的糖酵解包括、、和 4种途径；固定二氧化碳卡尔文循环途径，可分为、和 3个阶段。

4. 次级代谢是微生物生长至或，以为前体，合成一些对微生物自身生命活动无物质的过程。

5. 病毒的复制过程依其发生时间顺序可分为以下、、、和 5个阶段。

6. 基因工程的基本过程是、、、和获得所需的或表达出产物。

7. 产能代谢中，微生物通过磷酸化和磷酸化将某种物质氧化而释放的能量出存在ATP等高能分子中；光合微生物则通过磷酸化将光能转变成为化学能储存在ATP中。

【北京科技大学2012年考研专业课真题】物理化学B2012

北京科技大学2012年硕士学位研究生入学考试试题============================================================================================================= 试题编号： 627 试题名称：物理化学B （共 6页）适用专业：化学说明： 1.所有答案必须写在答题纸上，做在试题或草稿纸上无效。

2.符号$在右上角表示标准态, 例如p$表示一个标准压力100kPa. E$表示标准电动势等。

=============================================================================================================一、选择题( 共16题38分)1. 2 分用130℃的水蒸气(蒸气压为 2.7p$)与1200℃的焦炭反应生成水煤气：C+H2O−−→CO+H2。

如果通入的水蒸气反应掉70%，问反应后混合气体中CO的分压为多少? 设总压2.7p$不变。

( )(A) 0.72p$；(B) 1.11p$；(C) 2.31p$；(D) 1.72p$。

2. 2 分下列的过程可应用公式ΔH=Q进行计算的是：( )(A) 不做非体积功，终态压力相同但中间压力有变化的过程；(B) 不做非体积功，一直保持体积不变的过程；(C) 273.15 K，p$下液态水结成冰的过程；(D) 恒容下加热实际气体。

3. 2 分在101.325 kPa下，385 K的水变为同温下的水蒸气,对该变化过程，下列各式中哪个正确? ( )(A) ΔS体+ΔS环>0；(B) ΔS体+ΔS环<0；(C) ΔS体+ΔS环=0；(D) ΔS体+ΔS环的值不能确定。

4. 2 分某理想气体从同一始态(p1,V1,T1)出发，分别经恒温可逆压缩和绝热可逆压缩至同一压力p2，若环境所做功的绝对值分别为W T和W A，问W T和W A的关系如何? ( )(A) W T>W A；(B) W T <W A；(C) W T =W A；(D) W T和W A无确定关系5. 2 分在温度T时，纯液体A 的饱和蒸气压为p A*，化学势为μA*，并且已知在p$压力下的凝固点为T f*，当 A 中溶入少量与 A 不形成固态溶液的溶质而形成为稀溶液时，上述三物理量分别为 p A ，μ A ，T f ，则 ( )(A) p A *< p A ，μA *<μA ，T f * < T f ； (B) p A *> p A ，μA *<μA ，T f * < T f ；(C) p A *< p A ，μA *<μA ，T f * > T f ； (D) p A *> p A ，μA *>μA ，T f * > T f 。

传热学-稳态导热例题

专题二稳态热传导
【解】
专题二稳态热传导
【名校真题解析】29 （北京科技大学2012）【计算题】考察一管长6m, 内、外径分别为7.4cm、
8.0cm，导热系数为14W/(m·℃)的压缩空气管道。管的外表面由总功率为300W的电阻带均匀加热，外包绝热层，通过绝热层的散热损失为15％。管内空气的平均温度为−10℃ ，管道内表面的对流换热系数为30 W/(m2·℃)。试：
专题二稳态热传导
温度场分布：
r=r2 处有最高温度：
t2
tf
q h
t2
150 ℃ 1.05105 3 500
q 2 (t1 t2 ) 2
t1
q 2 2
t2
186.30C
燃料层控制方程：料层边界条件：
燃料层温度分布：
t
Φ
21
1
2
2
x2
t1
燃料层最高温度：
t0
t1
1 22
21
196.8℃
【计算题】一长为L的长圆柱内热源为，常物性，导热系数为λ，左端面和侧面都绝热，右端与流体接触，温度为tf，表面传热系数为 h，求
①写出微分方程和边界条件 ②温度分布 ③最大温度tmax
【解】控制方程:
边界条件:
第一次积分:
第二次积分:
x L,
tL
Φ 2λ
L2
c2
tf
L ; h
c2 =t f
L h
Φ 2λ
L2
温度分布: 当x=0时，取得最大温度:
专题二稳态热传导
【名校真题解析】 25（北京科技大学2011）【计算题】考察一功率为800W的家用电熨斗

【北京科技大学2012年考研专业课真题】土木工程施工2012

北京科技大学2012年硕士学位研究生入学考试试题============================================================================================================= 试题编号： 844 试题名称：土木工程施工（共 2 页）适用专业：建筑与土木工程（专业学位）说明：所有答案必须写在答题纸上，做在试题或草稿纸上无效。

总分：150分=============================================================================================================一、简答题（50分）1、网络图通常有几种？网络优化主要有哪3种?（7分）2、建筑地基可能存在哪五类问题？5分)3、脚手架按按材料不同分类有哪些？按支撑固定方式不同分类有哪些？(6分)4、预应力筋超张拉主要是为了考虑哪几方面引起的应力损失。

（4分）5、钢筋的加工内容包括哪些？（5分)6、钢筋冷拉有哪些控制方法？（2分）7、土方工程中，根据岩土的开挖难易程度分为哪些名称类土？（8分）8、影响新浇混凝土侧压力的主要因素有哪些？（5分）9、预制桩按施工方法有哪些？灌注桩按施工方法分为哪些？（8分）二、对错判断题（对画√；错画X；每题2分，共20分）1)正铲是自上向下切土，开挖停机面以下的土，适用于开挖一至四类土。

2)土经过烘干后压实，可测得土的最大干密度，用于控制土的密实度。

3)搅拌桩是通过高压泥浆切割土体，形成水泥土，从而加固地层。

4)灌注桩钻孔泥浆正循环是：泥浆池→泥浆泵→钻杆→钻头→钻孔与钻杆环形孔隙→泥浆池；5)刚性基础变形小，所以承载能力大。

6)用等值梁法设计单支点钢板桩时，取土压力强度为零的位置点为反弯点。

7)混凝土搅拌的二次投料法就是先将水泥投入搅拌机，加水进行预搅拌一半时间，然后再加入砂石子搅拌的一种投料方法。

北京科技大学2012年硕士研究生入学考试

学（化学（农）普通化学物理化学B 生物化学与分子生物学
分析化学高分子物理普通生态学控制工程基础物理化学A 冶金物理化学传热学材料力学C 材料科学基础电路与数字电子技术高分子化学模拟电子技术与数字电子基础设计基础化工原理概论矿物加工原理材料力学D 微生物学B 理论力学A 矿山岩石力学无机化学结构力学渗流力学土力学地基基础暖通空调工程流体力学信号系统与数字电路混凝土结构自动检测技术电路理论与数字技术电路理论与自动控制原理选矿学水处理原理岩石力学现代生产管理汽车理论信号系统与数字电路
北京科技大学2012年硕士研究生入学考试年硕士研究生入学考试北京科技大学
试题编号 199 204 315 619 627 628
629 631 801 802 804 809 811 813 814 815 816 817 818 819 821 822 823 826 831 833 836 838 839 840 842 843 845 849 850 853 854 856 860 861 864 868
871 875 876
普通计算器(无存储、记忆功能）、直尺圆规、直尺普通计算器(无存储、记忆功能）、直尺
各科目
铅笔、铅笔、黑色签字笔铅笔、铅笔、黑色签字笔不带字典存储和编辑功能、不带字典存储和编辑功能、具有对数及幂指数计算功能的计算器普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）
普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）、直尺、铅笔、橡皮; 直尺普通计算器(无存储、记忆功能）、直尺普通计算器(无存储、记忆功能）、直尺普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）直尺普通计算器(无存储、记忆功能）、直尺普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）、直尺绘图工具、种类不限普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）、直尺普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）、直尺、圆规、铅笔、橡皮普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）、直尺普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）、直尺普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）、直尺普通计算器(无存储、记忆功能）、直尺、铅笔、橡皮普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）普通计算器(无存储、记忆功能）、直尺、圆规、量角器普通计算器(无存储、记忆功能）、直尺直尺、铅笔、橡皮普通计算器(无存储、记忆功能）、直尺

北京科技大学传热学第2章习题答案

heat flux through the outer surface is determined to be
•
•
•
qS
= QS A
=
QS 2πr2 L
=
0.85 × 300W
2π (0.04m)(6m)
=
169.1W
/
m2
Noting that heat transfer is one-dimensional in the radial r direction and heat flux is in the negative r
Taking the direction normal to the surface of the wall to be the x direction with x=0 at the left surface, the
mathematical formulation of this problem can be expressed as
Properties: The thermal conductivity is given to be k = 14W / m ⋅ DC .
Analysis: (a) Noting that the 85% of the 300W generated by the strip heater is transferred to the pipe, the
Assumptions: 1 Heat conduction is steady and one-dimensional since the surface area of the base plate is large relative to its thickness, and the thermal conditions on both sides of the plate are uniform . 2 Thermal conductivity is constant. 3 There is no heat generation in the plate. 4 Heat loss through the upper part of the iron is negligible.

【北京科技大学2012年考研专业课真题】暖通空调2012

北京科技大学2012年硕士学位研究生入学考试试题============================================================================================================= 试题编号： 840 试题名称：暖通空调（共 5 页）适用专业：供热、供燃气、通风及空调工程说明：所有答案必须写在答题纸上，做在试题或草稿纸上无效。

=============================================================================================================一、单项选择题（共30分，每小题2分）1. 低温热水地板辐射采暖计算热负荷时，将室内温度取值降低2℃，是因为（）。

A．相同热舒适条件下地板辐射采暖比对流采暖方式室温低2℃B．地板辐射采暖效率高C．地板辐射采暖散热面积大D．地板辐射采暖水温低2. 在确定采暖房间所需柱型散热器面积时，当散热器组装片数大于测试片数时，应乘以（）的散热器组装片数修正系数。

A．小于1 B．1 C．大于1 D．小于等于13. 对被楼梯、扶梯、天井等贯通的房间，散热器应在（）多放置。

A．底层B．顶层C．中间层D．任一层4. 带有混合水泵的直接连接热水供暖系统，若网路的设计供回水温度为130/70℃，供暖用户的设计供回水温度95/70℃，则混合水泵的设计混合比为（）A．0.42 B．0.58 C．1.4 D．2.45. 按户计量的热水采暖系统，户内系统不宜采用（）A．单管水平跨越式B．单管水平顺流式C．上供下回双管水平式D．下供下回双管水平式6. 确定空调房间围护结构的传热系数时，可以不考虑的因素是（）。

A. 室内外温差、恒温精度B. 建筑物的用途和空调的类别C. 空调制冷系统的投资和运行费用D. 空调新风量7. 下列关于空调舒适性的说法中，哪一项是正确的？（）A. 舒适性空调的目的就是使人舒适B. 夏天空调房间室内温度降低，人体舒适度将提高C. 室内新风量越大越好D. 长期生活在舒适的室内环境中对人体健康不利8. 下列关于空调冷负荷的说法中正确的是（）。

北京科技大学普通化学2012年考研专业课初试真题

(D) 线状光谱
13、正极为饱和甘汞电极，负极为氢电极，分别插入以下各种溶液，组成四种电池，使电池电动势最大的溶液是（） -3 -3 (A) 0.10 mol·dm HAc (B) 0.10 mol·dm HCOOH (C) 0.10 mol·dm-3 NaAc (D) 0.10 mol·dm-3 HCl 14、下列轨道上的电子，在xy平面上的电子云密度为零的是 ( ) (A) 3pz (B) 3 d z 2 (C) 3s (D) 3px 15、易于形成配离子的金属元素是位于周期表中的（） (A) p区 (B) d区和ds区 (C) s区和p区 (D) s区 16、下述叙述中正确的是（） (A) 在恒压下，凡是自发的过程一定是放热的 (B) 因为焓是状态函数，而恒压反应的焓变等于恒压反应热，所以热也是状态函数
2、极化能力最强的离子应具有的特性是 (A)离子电荷高、离子半径大 (C)离子电荷低、离子半径小
(B)离子电荷高、离子半径小 (D)离子电荷低、离子半径大
3
3、对弱酸与弱酸盐组成的缓冲溶液，若c(弱酸):c(弱酸根离子)=1:1时，该溶液的p H值等于
(A) pK w (B) pK a
（ (C) c(弱酸)
5、将过氧化氢加入用稀H2SO4酸化过的KMnO4水溶液中，发生反应。对于此反应中的过氧化氢，下列说法正确的是 (A) 是氧化剂 (B) 是还原剂 (C) 分解成氢气和氧气（）（）
(D) 被H2SO4氧化
6、晶格能的大小，常用来表示 (A) 共价键的强弱 (C) 离子键的强弱 (B) 金属键的强弱 (D) 氢键的强弱
5
(C) 液体的饱和蒸汽压
(D) 化学反应速率常数k
22、难溶电解质CaCO3在浓度为0.1 moldm3的下列溶液中的溶解度比在纯水中的溶解度大的有

北京科技大学综合英语2012年考研专业课初试真题

北京科技大学2012年硕士学位研究生入学考试试题================================================================================================= ============试题编号： 874 试题名称：综合英语（共 7 页）适用专业：外国语言学与应用语言学英语语言文学说明：所有答案必须写在答题纸上，做在试题或草稿纸上无效。

================================================================================================= ============说明： This paper covers FOUR subjects: (1) A Survey of Great Britain and the United States, (2) British Literature, (3) American Literature, and (4)General Linguistics. You have 180 minutes to complete the whole paper.Please time your pace well.Part I. Survey of Great Britain and the United States (30 points)I. Fill in the blanks:Read the following unfinished statements or questions carefully. For each unfinished sentence or question four suggested choices marked A, B, C, and D are given. Choose the ONE that you think best completes the statement or answers the question. Write the letter of your choice in the corresponding space on your Answer Sheet after the numbers. (10 points)1. Thanksgiving Day is a historical, national and religious holiday that began with the pilgrims. The first was celebrated by the English settlers in __________ on December 13, 1621.A. Plymouth, MassachusettsB. VirginiaC. James TownD. California2. In the early 1960s hope had run high among millions of Americans. Kennedy’s call for a ___________ had inspired many Americans to work to wipe out poverty and end segregation and voting rights abuses,A. New DealB. the Civil Rights ActC. New FrontierD. the Law on Poverty3. Britain is one of the world’s major centers for theatre, and it has some world-famous contemporary playwrights like ____________ whose representative plays include The Caretaker and The Homecoming.A. Tom StoppardB. Harold PinterC. Arnold WeskerD. David Hare4. ___________ is uniquely related to the Crown in that the Sovereign must be a member of that Church, and it is not free to change its form of worship without the consent of Parliament.A. Christian churchB. The Church of IrelandC. Catholic churchD. The Church of England5. The post-war years were not peaceful to England. When Nasser, the Egyptian president, nationalized the Suez Canal in__________, British and French forces invaded Egypt. The action was widely condemned at home and abroad.A. 1960B. 1956C. 1945D. 19326. Under ________, the feudal system in England was established. One feature of the feudal system of England was that all landowners took the oath of allegiance for the land they held, not only to their immediate lord, but also to the king.A. King EdwardB. King AlfredC. Roman conquestD. William the conqueror7. The three conditions on which the Sino-US diplomatic relation was established are: the U.S.A must withdraw its troops from Taiwan and the Taiwan Straits, end diplomatic relations with Taiwan and cancel ___________.A. the Taiwan Relations ActB. the Mutual Defence TreatyC. American allianceD. Shanghai Communique8. The American Constitution is the oldest written constitution in the world. It was originally in the form of __________, which had little in common with the later officially adopted constitution in 1787.A. Common SenseB. Continental CongressC. the Articles of ConfederationD. Declaration of Independence9. During the last decades of the 19th century and the first decade of the 20th century, some American writers in their works reported truthfully and objectively the life in the slums. They called themselves naturalists, and _______ who was famous for Sister Carrie and An American Tragedy, was one of the representatives.A. Theodore DreiserB. Jack LondonC. Richard WrightD. Ernest Hemingway10. The 18th century was an age of Enlightenment in America. _________ was aspokesman of it: people still believed that God was the center of the world, but they began to see the importance of man, of reason and order.A. Thomas JeffersonB. Lord CornwallisC. Benjamin FranklinD. George WashingtonII. Answer the following questions in the corresponding space on your Answer Sheet.(20 points, 5 for each)1. What is meant by the term “welfare state” in Britain?2. What do you know about James Joyce and his works?3. What were the causes of New Conservatism that led to the election of RonaldReagan as the president?4. Who were the first Americans? How was America discovered by Europeans inthe 15th century?Part II. British Literature (30 points)I. Fill in the blanks:write your answers on your Answer Sheet after the numbers. (8 points)1. The shift in English literature from emphasis on reason to instinct and emotion was intellectually prepared for by a number of thinkers in the later half of the 18th century. One is __________, the French philosopher who is generally regarded as the father of romanticism. Another two are Edmund Burke and Thomas Painer.2. Except for Satan in Paradise lost, the revengeful Heathcliff in __________ has no equal in English literature. His intense love for Catherine and his relentless revenge on his enemy mark him a unique figure.3. In the first two books of ________ the Christian God is described by Satan and his followers as a tyrant, while on the other hand all the fallen angels in council voice unanimously their determination to fight for their freedom and their will to defy tyranny and plot revenge.4. The title of Thackeray’s novel Vanity Fair is taken from John Bunyan’s ________, in which the protagonist Christian passes a Vanity Fair, where all sorts of vanity are sold.5. Although the novel was the predominating genre of literature in the _______age, there were still some prominent romantic poets like Alfred Tennyson and Robert Browning.6. The works by the Bronte sisters are marked by a new concept of women as heroines of vital strength and passionate feelings. In Jane Eyre, it is Jane’s rebelliousness, her dislike for servility, and her insistence on _______ that make the book unique.7. As the last important novelist of the Victorian age, Hardy was ______ in his view of life. His philosophy was that every thing in the universe is determined by the Immanent Will, which is hostile towards human beings’ desire for joy.8. In the last thirty year of the 16th century there was a flourishing of drama which England had never seen before. Several predecessors to Shakespeare were called University Wits, among whom the most prominent was Christopher Marlowe, who was famous for ____________.II. Identify the title of the work of the following excerpts: write the titles of the works on your Answer Sheet. (10 points)1. Earth has not anything to show more fair:Dull would he be of soul who could pass byA sight so touching in its majesty…2. Jimmy: God, how I hate Sundays! It’s always so depressing, always the same. Wenever seem to get any further, do we? Always the same ritual. Reading thepapers, drinking tea, ironing. A few more hours, and another week gone. 3. The isles of Greece, the isles of Greece!Where burning Sappho loved and sung,Where grew the arts of war and peace,Where Delos rose, and Phoebus sprung!4. Old Mrs. Linton paid us several visits, to be sure, and set things to rights, and scolded and ordered us all; and when Catherine was convalescent, she insisted on conveying her to Thrushcross Grange: for which deliverance we were very grateful.5. To record of Mr Dombey that he was not in his way affected by this news (his wife is dying), would be to do him an injustice. He was not a man of whom it could properly be said that he was ever startled, or shocked ….6. On nothing per annum, then, and during a course of some two of three years, of which we can afford to give but a very brief history, Crawley and his wife lived very happily and comfortably at Paris. It was in this period that he quitted the Guards, and sold out of the army.7. Go, and catch a falling star,Get with child a mandrake root,Tell me, where all past years are,Or who cleft the Devil’s foot…8. Histories make men wise; poets witty; the mathematics subtle; natural philosophy deep; moral grave; logic and rhetoric able to contend.9. I grant this food will be somewhat dear, and therefore very proper for landlords, who, as they have already devoured most of the parents, seem to have the best title to the children. Infant’s flesh will be in season throughout the year....10. She speaks, yet she says nothing. What of that?Her eye discourses: I will answer it.I am too bold, ‘tis not me she speaks.III. Answer the question concerning the following paragraph from The Merchant of Venice: write your answers on your Answer Sheet. (12 points)The quality of mercy is not strain’d,It droppeth as the gentle rain from heavenUpon the place beneath: it is twice bless’d;It blesseth him that gives, and him that takes:‘Tis mightiest in the mightiest; it becomesThe throned monarch better than his crown;His sceptre shows the force of temporal power,The attribute to awe and majesty,Wherein doth sit the dread and fear of kingsBut mercy is above this sceptral sway:It is enthroned in the hearts of kings,And earthly power doth then show likest God’sWhen mercy seasons justice.Question: Paraphrase the lines above. (Pay special attention to the words and phrases underlined.)Part III. American Literature (30 points)I. Fill in the blanks:write your answers on your Answer Sheet after the numbers.(10 points)1. Culminated around the 1840s, from Jefferson’s death in 1826 to the Civil War in 1861, was the age of the literary giants. They developed the new national literature of America founded by__________ and______________.2. With open, fluid and long lines sweeping across the pages, ______ wrote in his poems about all kinds of things, the ants, leaves, our hearing and even breathing, expressing his love of life and philosophy about life particularly in the image of grass.3. Name two fiction writers in the first part of 19th c American literature:____________, ___________.4. The 1920s was another golden age of American literature, which boasted of a number of great writers. Among them, ________ is regarded as the spokesman of the Lost Generation; ____________ as an active participant of the Jazz Age, and ____________ as a representative of the Harlem renaissance.5. With _________ as his representative work, and depicting sympathetically about the poor, oppressed California farmers, migrants, and laborers, John Steinbeck is recognized as the foremost writer of the Great Depression in America.6. The 1960s are remembered as a time of widespread social disturbances in America. In the South, ________ organized the black Civil Rights Movement, demanding fully equal treatment for blacks under the law.II. Identify the title of the work of the following excerpts: write the titles of the works on your Answer Sheet. (8 points)1. To go into solitude, a man needs to retire as much from his chamber as from society. I am not solitary whilst I read and write, though nobody is with me. But ifa man would be alone, let him look at the stars.2. And the Raven, never flitting, still is sitting, still is sittingOn the pallid bust of Pallas just above my chamber door;3. A child said what is grass? fetching it to me with full hands,How could I answer the child? I do not know what it is any more than he.I guess it must be the flag of my disposition, out of hopeful green stuff woven.4. A Slave Warehouse! Perhaps some of my readers conjure up horrible visions ofsuch a place. They fancy some foul, obscure den, some horrible Tartarus“informis, ingens, cui lumen ademptum.” But no, innocent friend! In these days men have learned the art of sinning expertly and genteelly ….5. “Miss Watson your runaway nigger Jim is down here two mile below Pikesville and Mr. Phelps has got him and he will give him up for the reward if you send.”6. When Caroline Meeber boarded the afternoon train for Chicago, her total outfit consisted of a small trunk,…It was in August, 1889. She was eighteen years of age, bright, timid, and full of illusions of ignorance and youth.7. Down, down, he swam till his arms and legs grew tired and hardly moved… This hurt was not death, was the thought that oscillated through his reeling consciousness. Death did not hurt. It was life, the pangs of life, this awful, suffocating feeling; it was the last blow life could deal him.8. My long two-pointed ladder’s sticking through a treeToward heaven still,And there’s a barrel that I didn’t fillBeside it, and there may be two or threeApples I didn’t pick upon some bough.III. Essay questions: write your answers on your Answer Sheet. (12 points)Read the except from Hemingway’s “In Another Country”, a story about the First World War, and then answer the questions.We all had the same medals…. The boys at first were very polite about my medals and asked me what I had done to get them. I showed them the papers …. After that their manner changed a little toward me, although I was their friend against outsiders. I was a friend, but I was never really one of them after they had read the citations, because it had been different with them and they had done very different things to get their medals. I had been wounded, it was true; but we all knew that being wounded, after all, was really an accident. I was never ashamed of the ribbons, though, and sometimes, after the cocktail hour, I would imagine myself having done all the things they had done to get their medals; but walking home at night through the empty streets with the cold wind and all the shops closed, trying to keep near the street lights, I knew that Ì would never have done such things, and I was very much afraid to die, and often lay in bed at night by myself, afraid to die and wondering how I would be when back to the front again.The three with the medals were like hunting-hawks; and I was not a hawk, although I might seem a hawk to those who had never hunted; they, the three, knew better and so we drifted apart.Questions:1. What kind of writer is Hemingway?2. How different are the metals of the boys and the narrator? And what differentcourage is depicted in the paragraph here through the images of the three boys and the speaker? How can you understand the image of hawks in the secondparagraph?Part IV General Linguistics (60 points)Part I Define the following linguistic terms in your own words (20 points, 4 points each).1.Metalanguage2.Allophones3.Inflection4.The referential theory5.The illocutionary actPart II Finish the following according to the requirements for each (15 points, 5 points each):1.What is macrolinguistics? List no less than three branches of macrolinguistics anddefine them briefly.2. Discuss the difference between DEEP and SURFACE structures.3. What is the difference between sense and reference? Use specific examples toillustrate three kinds of sense relations.Part III Provide as much information as you know about each of the following topics (25 points, 12.5 points each).1.What are the central notions Halliday’s systemic functional grammar?2. What is the theory of conversational implicature? Discuss the characteristics ofimplicature.。

【北京科技大学2012年考研专业课真题】综合日语2012

北京科技大学2012年硕士学位研究生入学考试试题=========================================================================================================试题编号： 873 试题名称：综合日语（共 6 页）适用专业：日语语言文学说明：所有答案必须写在答题纸上，做在试题或草稿纸上无效。

==========================================================================================================この試験は、「日本語学」（60点）「日本文学」（60点）及び「日本文化」（30点）の３部分から構成されている。

満点は150点となり、試験時間は3時間である。

すべての問題は日本語で答え、その答えは答案用紙に記入せよ。

第一部分日本語学（60点）１．例のように、Ａ－Ｄの中に、＜＞内に示した観点から見れば他の選択肢と性質が異なるものが一つある。

次の（１）～（10）について、それぞれ一つずつ選べ。

（2点×10＝20点）例：＜表記＞Ａ．大学Ｂ．掃除Ｃ．野菜Ｄ．メガネ答え：Ｄ（１）＜造語法＞Ａ．学割Ｂ．卒論Ｃ．短大Ｄ．複雑（２）＜品詞（下線部）＞Ａ．ある日Ｂ．眠る女Ｃ．去る５月Ｄ．いわゆる志士（３）＜複合格助辞「への」の意味用法＞Ａ．異文化への理解Ｂ．首相への批判Ｃ．提案への賛成Ｄ．取引先への接待（４）＜動詞の種類＞Ａ．起きるＢ．飽きるＣ．走るＤ．着る（５）＜連語の種類＞Ａ．泡を食うＢ．年を食うＣ．晩飯を食うＤ．道草を食う（６）＜アスペクト的な意味＞Ａ．母は料理を作っている。

Ｂ．雤が降っている。

Ｃ．赤ちゃんは寝ている。

Ｄ．彼は小説を20冊以上書いている。

（７）＜形容詞の種類＞Ａ．四川料理は辛い。

Ｂ．新しいパソコンがほしい。

北京科技大学传热学试题(2003年-2008年)

2
真实温度。六、（15 分）试给出图 1 所示平板温度分布 T（x）的解析表达式，设平板在 x 1 和 x 2 处分别有均匀的表面温度 T1 和 T2 ，导热系数随温度线性变化：k= k 0 （1+bT）。七、（15 分）以逆流式换热器为例，试推导换热器设计公式 Q=K△tF 中平均温压△t 的计算式：△t=
2
ε 1 =0.5，ε 2 =0.05 和 D1 =0.8m，问两表面之间的净辐射能交换是多 c. 若 D2 增加至 20m，且
6
ε 1 =0.2，表面 2 温度和发射率分别为方向无限长。表面 1 的温度和发射率分别为 t1 =200℃，
ε 2 =0.7,表面 3 的发射率为 t 2 =27℃， ε 3 =0.5，单位长度热流 q 3 =1000W/m。试确定表面 3 的
温度和表面 1，2 的单位长度净辐射换热量。六、（ 20 分）用热电偶测温计测得炉膛烟气温度 t1 =798 ℃。设已知水冷壁管外表面温度，烟气可近似地当做透 t w =580℃，烟气对测温计表面的对流换热系数α =60W/（ m 2 ·℃）
三个面的辐射率分别为 ε 1 、ε 2 和ε 3 ，三个面上的温度分别为 T1 、 T2 和 T3 ，试画出该辐射系统的等效辐射网络图，并列出求解此辐射系统的节点方程组。
北京科技大学 2004 年硕士学位研究生入学考试试题
一、（30 分，每小题 6 分）简要回答下列问题 1、试分析气体辐射的特点。 2、名词解释：热导率λ 、对流换热系数α 、辐射常数σ 0 以及材料的热辐射率ε 。 3、解释下列名词：层流边界层、湍流边界层、湍流核心、粘性底层、主流区、雷诺类比。 4 、为什么改变内部流动截面形状会改变换热效果？试用充分发展湍流的对流换热公式 N u f =0.023 Re f Pr f 解释之。 5、扼要阐明下列相似准则的表达式和物理意义： Bi Fo Gr Nu Re Eu 二、（20 分）试给出图 1 所示平板温度分布 T（x）的解析表达式，设平板在 x1 和 x 2 处分别有均匀的表面温度 T1 和 T2 ，导热系数随温度线性变化：k= k 0 （1+bT）。三、（20 分）考察两个漫射的无限大的平行灰表面，其相隔距离很小，若两表面的黑度均为 0.8，为了要使两表面之间的辐射热流减少至原来的 1/10，问所放置在其之间的很薄、且导热热阻可以忽略的辐射热屏的黑度应是多少？四、（30 分）一个套管式换热器，饱和蒸汽在内管中凝结，使内管外壁温度保持在 100℃，初温为 25℃、质量流量为 0.8kg/s 的水从套管换热器的环形空间中流过，换热器外壳绝热良好。环形夹层内管外径为 40mm，外管内径为 60mm，试确定把水加热到 55℃时所需的套管长度以及管子出口截面处的局部热流密度。不考虑温差修正，水的物性参数如下：导热系数（或称热导率） λ =0.635W/(m· ℃)；动力粘度μ =653.3× 10 Pa· s；比热 c p =4174J/(kg· ℃)；普朗特数 Pr=4.31 。管槽内旺盛紊流流体与壁面间的对流换热的准数方程为 Nu=0.023 Re

【北京科技大学2012年考研专业课真题】高分子物理2012

北京科技大学2012年硕士学位研究生入学考试试题============================================================================================================= 试题编号： 631 试题名称：高分子物理（共 3 页）适用专业：化学说明：所有答案必须写在答题纸上，做在试题或草稿纸上无效。

=============================================================================================================一、选择题（共10题，每题3分，共30分，请在每题的3个选项中选择1个最适合的填在题后的括弧里）。

1、高分子链内旋转受阻程度越大，其均方末端距（）A、越大B、越小C、趋于恒定值2、以下聚合物中内聚能密度最高的是（）A、橡胶B、塑料C、纤维3、某一聚合物薄膜当温度升至一定值时发生收缩，原因最可能是（）A、大分子解取向B、内应力松弛C、导热不良4、结晶聚合物在玻璃化转变温度以上时，可运动单元为（）A、所有链段B、非晶区中链段C、链段和整个大分子链5、外力作用频率降低，玻璃化转变温度（）A、增高B、降低C、基本不变6、聚合物处于橡胶态时其弹性模量随着形变增大而（）A、增高B、降低C、基本不变7、描述聚合物蠕变的最适宜模型是（）A、弹簧与粘壶串联B、弹簧与粘壶并联C、四元件模型8、完全非晶聚合物的应力-应变曲线一般不存在的阶段为（）A、屈服B、细颈化C、应变软化9、熔融指数（MI）如下的相同分子结构聚合物流动性最好的为（）A、3B、8C、1510、极性聚合物介电常数较大的主要原因是（）A、电子极化B、偶极极化C、原子极化二、判断题（共10题，每题2分，共20分，请在每题后的括弧内对正确的说法划“√”，对错误的说法划“×”）。

2012考研真题及答案

2012考研真题及答案2012年的考研真题是许多考生备战考研的重要资料，了解这些真题并熟悉其中的答案对于备考考研的同学来说是至关重要的。

在本文中，将为您介绍2012年的考研真题及其答案。

第一部分：数学一2012年的考研数学一科目主要涵盖了数学分析、高等代数和概率论等内容。

以下是部分考题及其答案的概要。

题一：设函数f(x)在区间[a,b]上连续，且在(a,b)内可导，证明：在(a,b)内至少存在一点ξ，使得f(b)-f(a)=(b-a)f' ( ξ )。

解析：根据罗尔定理，由于f(x)在[a,b]上连续，且在(a,b)内可导，那么在[a,b]上有f(a)=f(b)。

根据拉格朗日中值定理，存在一点ξ∈(a,b)，使得f' ( ξ )=(f(b)-f(a))/(b-a)。

所以，f(b)-f(a)=(b-a)f' ( ξ )。

题二：已知数列{a_n}的通项公式为a_n=2^n-3^n+4^n-5^n，求证数列{a_n}是等差数列。

解析：我们可以通过数学归纳法来证明这个结论。

当n=1时，a_1=2-3+4-5=-2。

当n=k时，假设a_k=2^k-3^k+4^k-5^k成立。

当n=k+1时，我们需要证明a_(k+1) =2^(k+1)-3^(k+1)+4^(k+1)-5^(k+1)也成立。

根据等差数列的性质，我们有a_(k+1)-a_k = (2^(k+1)-3^(k+1)+4^(k+1)-5^(k+1)) - (2^k-3^k+4^k-5^k)。

化简后可得a_(k+1)-a_k= -2 × 3^k + 3^(k+1) -2 × 5^k + 5^(k+1)。

通过整理和变换，我们得到a_(k+1)-a_k = -3^k (2-3) + 5^k (5-2) = 0。

因此，数列{a_n}是等差数列。

通过以上两道题目，我们可以看出2012年考研数学一科目的难度适中，考察了数学分析和代数的基本概念和推导方法。

北京科技大学传热学第4章习题答案

4-10 Ball bearings leaving the oven at a uniform temperature of 900 ℃ are exposed to air for a while before they are dropped into the water for quenching. The time they can stand in the air before their temperature falls below 850 ℃ is to be determined.Assumptions 1 The bearings are spherical in shape with a radius of 0r = 0.6 cm. 2 The thermal properties of the bearings are constant. 3 The heat transfer coefficient is constant and uniform over the entire surface. 4 The Biot number is Bi ﹤0.1 so that the lumped system analysis is applicable (this assumption will be verified).Properties The thermal conductivity, density, and specific heat of the bearings are given to be k =15.1 W/m ⋅°C,3/8085m kg =ρ, and ⋅=kg kJ C p /480.0°C.Analysis The characteristic length of the steel ball bearings and Biot number arem m D D D A V L c 002.06012.066/23=====ππ0167.0)/1.15()002.0)(/125(2=°⋅°⋅==C m W m C m W khL Bi c <0.1 Therefore, the lumped system analysis is applicable. Then the allowable time is determined to be132016.0)002.0)(/480)(/8085(/125−=°⋅°⋅===s m C kg J m kg C m W L C h V C hA b c p p ρρ s t e e T T T t T t s bt t 7.33090030850)()016.0(1=→=−−→=−−−−−∞∞ The result indicates that the ball bearing can stay in the air 3.7s before being dropped into the water.4-11 Large brass plates are heated in an oven. The surface temperature of the plates leaving the oven is to be determined.Assumptions 1center plane. 3 The thermal properties of the plate are constant. 4 transfer coefficient is constant and uniform over the entire surface. 5Fourier number is τ﹥transient temperature charts) are applicable (this assumption will be verified).Properties The properties of brass at room temperature are given to be C m W k °⋅=/110, s m /109.3326−×=αAnalysis The Biot number for this process is0109.0)/110()015.0)(/80(2=°⋅°⋅==C m W m C m W k hL BiThe constants 1λ and 1A corresponding to this Biot number are, from Table 4-1,Furnace, 700°C1λ=0.1039 and 1A =1.0018The Fourier number is4.90)015.0(min)/60min 10)(/109.33(2262=××==−m s s m Lat τ﹥0.2Therefore, the one-term approximate solution (or the transient temperature charts) is applicable. Then thetemperature at the surface of the plates becomes376.0)1039.0cos()0018.1()/cos(),(),()4.90()1039.0(111221===−−=−−∞∞e L L e A T T T t x T t L wallλθτλC t L T t L T °=→=−−2.446),(376.070025700),(4-12 A long cylindrical wood log is exposed to hot gases in a fireplace. The time for the ignition of the wood is to be determined.Assumptions 1 Heat conduction in the wood is one-dimensional since it is long and it has thermal symmetry about the center line. 2 The thermal properties of the wood are constant. 3 The heat transfer coefficient is constant and uniform over the entire surface. 4 The Fourier number is τ﹥0.2 so that the one-term approximate solutions (or the transient temperature charts) are applicable (this assumption will be verified).Properties The properties of wood are given to be k =0.17 W/m·℃,s m /1028.127−×=α. Analysis The Biot number is20(13.6/)(0.05)4(0.17/)hr W m C m Bi kW m C ⋅°===⋅° The constants1λand 1A corresponding to this Biot number are, from Table 4-1,1λ=1.9081 and 1A =1.46980J is determined from Table 4-2 corresponding to the constant 1λ,00.275J =The Fourier number is determined to be221(1.9081)010100(,)420500(/)(1.4698)(0.275)0.24910500t T r t T A e J r r eT T λττλτ−−∞∞−−=→=→=−− which is > 0.2. Therefore, the one-term approximate solution (or the transient temperature charts) can be used, with the understanding that the error involved will be under 2 percent. Then the length of time before the log ignites is22072(0.249)(0.05)486381.05min (1.2810/)r m t s m s τα−====×4-14 An orange is exposed to very cold ambient air. It is to determine whether the orange will freeze in 4 h in subfreezing temperatures. Assumptions 1 The orange is spherical in shape with a diameter of 8 cm. 2 Heat conduction in the orange is one-dimensional because of symmetry about the midpoint. 3 The thermal properties of the orange are constant, and are those of water. 4 The heat transfer coefficient is constant and uniform over the entire surface. 5 The Fourier number is τ﹥0.2 so that the one-term approximate solutions (orthe transient temperature charts) are applicable (this assumption will be verified).Properties The properties of the orange are approximated by those of water at the average temperature of about 5℃, k =0.571 W/m.℃ and s m C k p /10136.0)42051000/(571.0/26−×=×==ρα (Table A-9).Analysis The Biot number is0.1051.1)/571.0()04.0)(/15(20≈=°⋅°⋅==C m W m C m W k hr Bi The constants1λand 1A corresponding to this Biot number are, from Table 4-1,1λ=1.5708 and 1A =1.2732The Fourier number is22.1)04.0()/36004)(/10136.0(2262=××==−m h s h s m L tατ﹥0.2 Therefore, the one-term approximate solution (or the transient temperature charts) is applicable. Then thetemperature at the surface of the oranges becomes0399.05708.1)5708.1sin()2732.1(/)/sin(),(),()22.1()5708.1(001001100221===−−=−−∞∞rad e r r r r e A T T T t r T t r t sphλλθτλC t r T t r T °−=→=−−−−2.5),(0399.0)6(15)6(),(00which is less than 0°C. Therefore, the oranges will freeze.4-15 An area is subjected to cold air for a 10-h period. The soil temperatures at distances 0, 10, 20, and 50 cm from the earth’s surface are to be determined.Assumptions 1 The temperature in the soil is affected by the thermalconditions at one surface only, and thus the soil can be considered tobe a semi-infinite medium with a specified surface temperature. 2 The thermal properties of the soil are constant.Properties The thermal properties of the soil are given to beC m W k °⋅=/9.0 and s m /106.125−×=α.Orange T i = 15°C Ambient air–15°CWinds,–10°CSoil10°CAnalysis The one-dimensional transient temperature distribution in the ground can be determined from⎥⎥⎦⎤⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛+⎟⎟⎠⎞⎜⎜⎝⎛+−⎟⎠⎞⎜⎝⎛=−−∞k t h t x erfc k t h k hx t x erfc T T T t x T t t αααα2exp 2),(22 Where7.33/9.0)360010)(/106.1()/40(252=°⋅××°⋅=−Cm W s s m C m W k t h α 11387.332222==⎟⎟⎠⎞⎜⎜⎝⎛=k t h k t h αα Then we conclude that the last term in the temperature distribution relation above must be zero regardless of x despite the exponential term tending to infinity since (1) erfc(ξ)→0 forξ﹥4 (see Table 9-3) and (2)The term has to remain less than 1 to have physically meaningful solutions. That is,03.3321138exp 2exp 22≅⎥⎦⎤⎢⎣⎡⎟⎠⎞⎜⎝⎛+⎟⎠⎞⎜⎝⎛+=⎥⎥⎦⎤⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛+⎟⎟⎠⎞⎜⎜⎝⎛+t x erfc k hx k t h t x erfc k t h k hx αααα Therefore, the temperature distribution relation simplifies to⎟⎠⎞⎜⎝⎛−+=→⎟⎠⎞⎜⎝⎛=−−∞∞t x erfc T T T t x T t x erfc T T T t x T t t t t αα2)(),(2),(Then the temperatures at 0, 10, 20, and 50 cm depth from the ground surface becomex = 0:C T T T T erfc T T T t erfc T T T h T t t t t t t °−==×−+=−+=⎟⎠⎞⎜⎝⎛−+=∞∞∞∞101)()0()(20)()10,0(αx = 0.1m:⎟⎟⎠⎞⎜⎜⎝⎛××−−+=−)/360010)(/106.1(21.0)1010(10)10,1.0(25h s h s m m erfch m T C erfc °−=×−=−=5.89257.02010)066.0(2010 x = 0.2m:⎟⎟⎠⎞⎜⎜⎝⎛××−−+=−)/360010)(/106.1(22.0)1010(10)10,2.0(25h s h s m m erfch m T C erfc °−=×−=−=0.78519.02010)132.0(2010 x = 0.5m:⎟⎟⎠⎞⎜⎜⎝⎛××−−+=−)/360010)(/106.1(25.0)1010(10)10,5.0(25h s h s m m erfch m TC erfc °−=×−=−=8.26418.02010)329.0(20104-19 A cubic block and a cylindrical block are exposed to hot gases on all of their surfaces. The center temperatures of each geometry in 10, 20, and 60 min are to be determined.Assumptions 1 Heat conduction in the cubic block is three-dimensional, and thus the temperature varies in all x -, y , and z - directions. 2 Heat conduction in the cylindrical block is two-dimensional, and thus the temperature varies in both axial x - and radial r - directions. 3 The thermal properties of the granite are constant. 4 The heat transfer coefficient is constant and uniform over the entire surface. 5 The Fourier number is τ﹥0.2 so that the one-term approximate solutions (or the transient temperature charts) are applicable (this assumption will be verified).Properties The thermal properties of the granite are given to be k=2.5 W/m ⋅°C and s m /1015.126−×=α.Analysis:Cubic block : This cubic block can physically be formed by the intersection of three infinite plane walls of thickness 2L =5 cm.After 10 minutes: The Biot number, the corresponding constants, and the Fourier number are4.0)/5.2()025.0)(/40(2=°⋅°⋅==C m W m C m W k hL Bi → 1λ=0.5932 and 1A =1.0580104.1)025.0(min)/60min 10)(/1015.1(2262=××==−m s s m L tατ﹥0.2To determine the center temperature, the product solution can be written as[]3),0(),0,0,0(wall block t t θθ=()3121),0,0,0(τλ−∞∞=−−e A T T T t T t{}369.0)0580.1(50020500),0,0,0(3)104.1()5932.0(2==−−−et T →T (0,0,0,t) = 322.9℃After 20 minutes208.2)025.0(min)/60min 20)(/1015.1(2262=××==−m s s m L tατ﹥0.2{}115.0)0580.1(50020500),0,0,0(3)208.2()5932.0(2==−−−e t T →T (0,0,0,t) = 444.8℃After 60 minutes624.6)025.0(min)/60min 60)(/1015.1(2262=××==−m s s m L tατ﹥0.2 5Hot gases, 500°C{}00109.0)0580.1(50020500),0,0,0(3)624.6()5932.0(2==−−−e t T →T (0,0,0,t) = 499.5℃Note that τ﹥0.2 in all dimensions and thus the one-term approximate solution for transient heat conduction is applicable.Cylindrical block : This block can physically be formed by the intersection of a long cylinder of radius r 0=2.5cm and a plane wall of thickness 2L =5 cm. After 20 minutes208.2)025.0(min)/60min 20)(/1015.1(2262=××==−m s s m L tατ﹥0.221(2.5/) 2.5(40/)(0.025)k W m C Bi hL W m C m ⋅°===⋅° We can get: Plane wall:(0,)(0,)0.5wall i T t T t T T θ∞∞−==−Cylinder:(0,)(0,)0.24cyl i T t T t T T θ∞∞−==−So,(0,0,)(0,0,)(0,)(0,)0.50.240.12short cyl wall cyl i T t T t t t T T θθθ∞∞−===×=−→T (0,0,0,t) = 442.4℃。

【北京科技大学2012年考研专业课真题】分析化学2012

北京科技大学2012年硕士学位研究生入学考试试题=============================================================================================================试题编号： 629 试题名称：分析化学（共 4 页）适用专业：化学说明：所有答案必须写在答题纸上，做在试题或草稿纸上无效。

=============================================================================================================一、选择题( 共15题，30分，2分/题)1.为标定HCl溶液可以选择的基准物是-------------------------------------------------------------( )(A) NaOH (B) Na2CO3(C) Na2SO3(D) Na2S2O32.已知: H3PO4的p K a1 = 2.12, p K a2 = 7.20, p K a3 = 12.36, 调节磷酸盐溶液的pH至6.0时，其各有关存在形式浓度间的关系是------------------------------------------------------------------------------------( )(A) [HPO42-] > [H2PO4-] > [PO43-] (B) [HPO42-] > [PO43-] > [H2PO4-](C) [H2PO4-] > [HPO42-] > [H3PO4] (D) [H3PO4] > [H2PO4-] > [HPO42-]3.现有pH分别为2.00的强酸溶液和13.00的强碱溶液等体积混合，其pH为-------------- ( )( A ) 5.5 ( B ) 6.5 ( C ) 11.0 ( D ) 12.654.含有0.02 mol / L AlY－的pH = 4.5的溶液A、B两份。