新手必读：本站怎么获得下载流量?什么情况会被扣流量并封号或者封IP？ | 站务公告 - 考博论坛 - 免费考博论坛，
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新手必读：本站怎么获得下载流量?什么情况会被扣流量并封号或者封IP？
希望能够与大家共享资料，但是上传的地方满了，请问该怎么办
这网站不错
这个论坛确实好，但是获得流量却很难呀！&不知道为什么！
天啊！好不容易挣到可以下载一个，结果只有听力，其余的什么都没有。
版主啊！救救俺吧
为什么有流量限制啊 郁闷！
怎么获得呢？
为什么我上传不了呢？
怎么不能上传呢？
我已经通过邮箱发送了地址，怎么没有送流量呀
谢谢，明白
谢谢,努力获流量
流量很是头疼呢！怎么办？
获流量好难啊
我这留有考博士资料 大家来看看呀
&& 那位朋友需要考博士英语资料呀
我看了各位的考博资料了 觉得很有帮助
大家都想往哪里考博士呀
&& 我女朋友也在考博士 大家谁还有更多的英语资料呀
这样可以得流量吗？
问题是大家都准备复习&&没事时间整流量啊
写了考博日记，还是没有流量呢？看到很想要的东东，可是没法下啊
&& 博士考试越来越近了，大家都准备的怎么样了呀？
大家现在都在考博士冲刺么？
咱们一定都考上博士
&&大家谁有医学类别的考博士资料呀？我女朋友需要。
今天登陆的怎么人这么少呢？
请问新手怎么获得流量
考博士的日子越来越近了
对于广大硕士的理想 考博士&&大家都来床资料呀
考博士其实也很简单 只要心态正了
这个资料大家看看呀 不错么&一.名词解释(3分/题)&1.细胞外基质 2.细胞识别 3.G蛋白 4.多聚核糖体 5.端粒酶&6.增强子 7.细胞分化 8.胚胎诱导作用 9.基因的组织特异性表达&10.Hayflick界限&二选择题(3分/题)&1.信号传递中的第二信使之一是______.&A.二酰基甘油 B.ATP C.纤粘连蛋白 D.膜受体蛋白&2.信号蛋白的信号肽的切除发生在_______.&A.高尔基体 B.过氧化物酶体 C.线粒体膜 D.内质网膜&3.介导高等植物细胞间物质交换的细胞连接方式是_______.&A.胞间连丝 B.锚定连接 C.化学突触 D.紧密连接&4.ATP合成酶定位在线粒体的_________.&A.膜间隙 B.外膜 C.内膜 D.基质&5.亲核蛋白进入细胞核的方式是_________.&A.被动扩散 B.基因转移 C.主动运输 D.胞吞-胞吐作用&6.核仁的消失发生在细胞周期的______.&A.G1期 B.S期 C.M期 D.G2期&7.hnRNA的修饰加工发生在____________.&A.粗面内质网 B.光面内质网 C.细胞基质 D.细胞核&8.抑癌基因之一是________.&A.c-fos B.v-jun C.v-raf D.p53&9.癌细胞的主要特点之一是________.&A.细胞间粘着性增强 B.缺少接触抑制作用&C.对生长因子的需求量上升 D.增殖力下降&10.细胞调亡的一个重要特点是_______.&A.DNA随机断裂 B.DNA发生核小体间的断裂&C.70S核糖体中的rRNA断裂 D.80S核糖体中rRNA断裂&三.问答题(8分/题)&1.为什么说细胞是生命活动的基本单位?&&&2.举例说明按细胞分裂潜力划分的几种细胞类型.&&&3.简述一种获取同步化细胞的方法.&&&4.说明细胞核全能性与细胞全能性的异同.&&&5.试举例说明细胞质决定成分不均匀分布的意义.
一．&&&&写出下列各化学物的结构式（20分）&⑴ β-D-葡萄糖(β-D-Glucose)&&⑵ 乳糖(Lactose) ⑶ 5’-腺苷三磷酸(5’-Adenosine triphosphate) ⑷ 磷脂酰胆碱 (Phosphatidylcholine) ⑸ 4-羟基脯氨酸(4-Hydroxyproline) ⑹ 丹磺酰氯(Dansyl chloride) ⑺ 丝氨酸-甘氨酸-酪氨酸-丙氨酸-亮氨酸(Ser-Gly-Tyr-Ala-Leu) ⑻ 7-脱氢胆固醇(7-Dehydrocholesteol) ⑼ 烟酰胺腺嘌呤二核苷酸(辅酶I,NAD+)(Nicotinamide adenine dinucleotide) ⑽ 鸟苷酸(Ornithine) ⑾ 1，3-二磷酸甘油酸(1,3-Bisphosphoglycerate) ⑿&&磷酸烯醇式丙酮酸(Phosphoenolpyruvate) ⒀ 琥珀酰辅酶A (Succinyl-CoA) ⒁ 延胡索酸(Fumarate) ⒂ 异柠檬酸(Isocitrate) ⒃ 氨甲酰磷酸(Carbamyl phosphate) ⒄ S-腺苷蛋氨酸(S-Adenosylmethionine) ⒅ 核酮糖-1，5-二磷酸(Ribulose-1,5-bisphosphate) ⒆ 肾上腺素(Epinephrine) ⒇生物素(Biotin)&二．&&&&名词解释（10分）&⑴ 蛋白质的等电点 ⑵ DNA熔点 ⑶ 蛋白质的去折叠和再折叠 ⑷ 碱基互补 ⑸ 酶的共价调节和别构调节 ⑹ 流体镶嵌模型 ⑺ 中心法则 ⑻ 酮体 ⑼ 氧化磷酸化和底物水平的磷酸化 ⑽内含子和外显子&三．&&&&完成下列酶催化的反应方程式（20分）&⑴ 葡萄糖激酶(Glucose kinase) ⑵ 丙酮酸脱氢酶复合物体系(Pyruvate dehydrogenase complex) ⑶ 乳酸脱氢酶(Lactate dehydrogenase) ⑷ α-酮戊二酸脱氢酶(α-Ketoglutarate dehydrogenase) ⑸谷丙转氨酶(Glutamate:pyruvate transaminase) ⑹ 丙酮酸羧化酶(Pyruvate carboxylase) ⑺ 苯丙氨酸羟化酶(Phenylalanine hydroxylase) ⑻ 甘油激酶(Glycerol kinase) ⑼ 顺乌头酸酶(Aconitase) ⑽核酮糖1，5-二磷酸羧化酶(Ribulose-1,5-diphosphate carboxylase)&四．&&&&判断下列是非题（是标“+”，非标“－”），如果命题是错的，请指出错误之处（10分）&（ ）⑴组成蛋白质的常见的20种氨基酸均有旋光性，并且均为L-氨基酸。&（ ）⑵辅基和辅酶的区别在于与酶蛋白结合的牢固程度不同，辅酶结合比较不牢固（非共价结合），而辅基结合较牢固（共价或配位键结合）。&（ ）⑶溴化氰（CNBr）常用于在蛋白质序列测定中断裂肽键，它专一性的切断甲硫氨酸羧基侧肽键。&（ ）⑷二维和多维核磁共振技术是目前用于测定蛋白质溶液构象的唯一手段。&（ ）⑸肌红蛋白是骨骼肌中储氧的蛋白质，血红蛋白是血液中输氧的蛋白质，两者都含有血红素，在空间结构上也极其相似，并且都为有别构效应的蛋白质。&（ ）⑹反竞争性抑制剂(I)首先与酶结合形成EI，EI再与底物(S)结合形成EIS，EIS不能分解成产物，I因此而起抑制作用。&（ ）⑺维生素B1是硫胺素，而硫胺素焦磷酸则为辅酶形式，它是羧化酶的辅酶。&（ ）⑻青霉素抑制细菌细胞壁合成主要是抑制粘肽合成的最后一步，即转肽作用。&（ ）⑼人体细胞内进行的乙醛酸循环，每进行一个循环消耗2分子的乙酰辅酶A，合成1分子的琥珀酸。&（ ）⑽呼吸链电子传递体中复合物Ⅱ为琥珀酸泛酸还原酶，它将还原型底物中的氢脱下，并将电子传递给泛醌Q，然后经呼吸链其它电子传递体最终交给电子受体氧。其释放能量，可使3分子的ADP转化为3分子的ATP。&&五．&&&&选择性填空（10分）&（ ）⑴下列几种糖中，哪一个是非还原糖？a.麦芽糖&&b.葡萄糖&&c.蔗糖&&d.乳糖&（ ）⑵当含有Ala,Asp,Leu,Arg的混合物在pH3.9条件下进行电泳时，哪一种氨基酸移向正极(+)？a.Ala&& b.Asp&& c.Leu&& d.Arg&（ ）⑶α-螺旋的稳定性不仅取决于肽链间的氢键形成，而且还取决于肽链的氨基酸侧链性质。试预测在室温下溶液中下列多聚氨基酸哪种能形成α-螺旋结构。a.多聚异亮氨酸，pH=7.0&&b.多聚精氨酸，pH=1.5&&c.多聚苏氨酸，pH=7.0&&d.多聚谷氨酸，pH=1.5&（ ）⑷下列几种酶中，哪一个酶需要金属离子作为辅基？a.羧肽酶&&b.核糖核酸酶&&c.溶菌酶&&d.胰凝乳蛋白酶&（ ）⑸当酶促反应速度为Vmax的80%时，其Km与[S]之间的关系如下列情况中的哪一种？a.Km=0.5[S]&& b.Km=0.25[S]&& c.Km=0.75[S]&&&&d.Km=[S]&（ ）⑹小孩长期缺乏哪一种维生素会导致软骨病或佝偻病？a.维生素C&& b.维生素B1&&&&c. 维生素D&& d.维生素E&（ ）⑺下列几种密码子中哪一个是终止密码子？a.UUU&&b.UAA&&c.AAU&&d.AGU&（ ）⑻光合磷酸化过程中，电子传递的最终受体是哪一个？a.NAD+&&b.NADP+&&c.O2&&d.FAD&& &（ ）⑼脂肪酸β-氧化一个循环有四步反应，分别由四个酶催化。它们中哪一个酶需要FAD作为辅基？a.脂酰辅酶A乙酰基转移酶&&b.β-羟脂酰辅酶A脱氢酶&& c.烯脂酰辅酶A水化酶&&d.脂酰辅酶A脱氢酶&（ ）⑽Western bootting是用于下列杂交技术中的哪一个？ a.DNA-DNA&&b.RNA-RNA&&c.DNA-RNA&&d.抗体-抗原结合&&六，叙述和问答题（30分）&⑴写出鸟氨酸循环（又称脲循环，）并注明催化各步反应的酶。&&&&⑵蛋白质结构层次包括哪些？试简述之。什麽是超二级结构？它主要包括哪几种形式（至少写出四种，用图简示之）？&&&&⑶什麽是DNA的半保留复制？简述它的实验证据是什麽？
清华大学1998年硕士入学考试化工原理试题 &&& &&&　一、填空题（12分）&&　　1、如图1所示，液体在等径倾斜管中稳定流动，则阀的局部阻力系数ξ与压差计读数Ｒ的关系式为_______。&&&　　2、评价塔板性能的标准是：&　　________________________，&　　________________________，&　　________________________，&　　________________________，&　　________________________。&&　　3、在低浓度难溶气体的逆流吸收塔中，若其他条件不变而入塔液体量增加，则此塔的液相传质单元数Ｎ(l)将_______，而气相总传质单元数ＮOG将_______，气体出口浓度ｙ(a)将_______。&&　　4、某精馏塔设计时，若将塔釜由原来间接蒸汽加热改为直接蒸汽加热，而保持x(F)，Ｄ／Ｆ，ｑ，Ｒx(D)不变，则Ｗ／Ｆ将_______，x(w)将_______，提馏段操作线斜率将_______，理论板数将_______。&&　　5、湿空气经预热后相对湿度φ将_______。对易龟裂的物料，常采用_______的方法来控制进干燥器的φ值。干燥操作的必要条件是_______，干燥过程是_______相结合的过程。&&　　6、某降尘室高2m，宽2m，长5m，用于矿石焙烧炉的炉气除尘。矿尘密度为4500千克每立方米，其形状近于圆球，操作条件下气体流量为25000立方米每小时，气体密度为0.6千克每立方米，粘度为3×10e-5Pas。则理论上能除去矿尘颗粒的最小直径为_______μｍ。&&　　二、选择题（10分）&&　　1、有一并联管路如图2所示，两段管路的流量、流速、管经、管长及流动阻力损失分别为Ｖ(1)、u(1)、d(1)、L(1)、h(f1)及Ｖ(2)、u(2)、d(2)、L(2)、h(f2)。若d(1)=2d(2)，L(1)=2L(2)，则&&　　（1）h(f1)/h(f2)＝（　）&　　Ａ、2；　　Ｂ、4;　　Ｃ、1/2;　　Ｄ、1/4;　　Ｅ、1&&　　（2）当管路中流体均作层流流动时，Ｖ(1)/Ｖ(2)=（　）&　　Ａ、2；　　Ｂ、4;　　Ｃ、8;　　　Ｄ、1/2;　　Ｅ、1&&　　（3）当两段管路中流体均作湍流流动时，并取λ(1)＝λ(2)，则Ｖ(1)/Ｖ(2)=（　）。&　　Ａ、2；　　Ｂ、4;　　Ｃ、8;　　　Ｄ、1/2;　　Ｅ、1/4&&&　　2、计算下列四种“数”时，其数值大小与单位制造选择有关的是_______。&　　Ａ、普兰德准数；　Ｂ、传热单元数NTU;　Ｃ、离心分离因数K;　　Ｄ、过滤常数K&&　　3、（1）板框压滤机洗涤速率为恒压过滤最终速率的1/4，这一规律只有在_______时才成立。&　　Ａ、过滤时的压差与洗涤时的压差相同；&　　Ｂ、滤液的粘度与洗涤液的粘度相同；&　　Ｃ、过滤压差与洗涤压差相同且滤液的粘度与洗涤液的粘度相同；&　　Ｄ、过滤压差与洗涤压差相同，滤液的粘度与洗涤液的粘度相同，且过滤面积与洗涤面积相同。&&　 　　（2）恒压过滤且介质阻力忽略不计时，如粘度降低20%，则在同一时刻滤液增加_______。&　　Ａ、11.8%；　　Ｂ、9.54%;　　Ｃ、20%;　　Ｄ、44%&&　　4、有两台同样的管壳式换热器，拟作气体冷却器用。在气、液流量及进口温度一定时，为使气体温度降到最底应采用的流程为_______。&　　Ａ、气体走管外，气体并联逆流操作；&　　Ｂ、气体走管内，气体并联逆流操作；&　　Ｃ、气体走管内，气体串联逆流操作；&　　Ｄ、气体走管外，气体串联逆流操作。&&　　5、请将你认为最恰当的答案填在（　）内。&&　　（1）与单级萃取相比，如溶剂比、萃取比、萃取相浓度相同，则多级逆流萃取可使萃余分率（　）。&　　Ａ、增大；　　Ｂ、减小;　　Ｃ、基本不变;　　Ｄ、增大、减小均有可能。&&　　（2）在B-S部分互溶的萃取过程中，若加入的纯溶剂量增加而其他操作条件不变，则萃取液浓度ｙ（A）（　）。&　　Ａ、增大；　　Ｂ、减小;　　Ｃ、不变;　　　　Ｄ、变化趋势不确定。&&　　三、计算题&&　　1、将20℃的水（粘度μ=0.001Pas）以30立方米每小时的流量从水池送至塔顶。已知塔顶压强为0.05MPa（表），与水池水面高差为10m，输水管φ89×4mm，长18m，管线局部阻力系数∑ξ=13（阀全开时），摩擦系数λ=0.3／（Ｒｅ(0.38次方)）。&　　（1）求所需的理论功率（kw）；&　　（2）一泵的特性可近似用下式表达：&　　　　　扬程：Ｈ＝22.4+5Ｑ-20Ｑ•Ｑ　　m&　　　　　效率：η＝2.5Ｑ-2.1Ｑ•Ｑ&　　式中Ｑ的单位为立方米每分钟。求最高效率点的效率，并评价此泵的适用性。如适用，求因调节阀门使功率消耗增加多少。（15分）&&　　2、在一新的套管换热器中，冷却水在φ25×2.5mm的内管中流动以冷凝环隙间的某蒸汽。当冷却水的流速为0.4m/s和0.8m/s时，测得基于内管外表面的总传热系数分别为1200瓦每平方米开尔文和1700瓦每平方米开尔文。水在管内为湍流，管壁的导热系数为45w/m•K。水流速改变后可认为环隙间冷凝的传热膜系数不变，试求：&　　（1）当水的流速为0.4m/s时，管壁对水的对流传热系数为多少？&　　（2）管外蒸汽冷凝的对流传热系数为多少？&　　（3）若操作一段时间后，水流速仍维持0.4m/s，但测得的总传热系数比操作初期下降10%，试分析可能的原因，并论述此时蒸汽的冷凝量是否也下降10%。（13分）&&　　3、进料量为9000kg/h，浓度为1%（质量分率）的盐溶液在40℃下进入单效蒸发器并被浓缩到1.5%。蒸发器传热面积为39.1平方米，蒸发室绝对压强为0.04MPa（该压力下水的蒸发潜热r'=2318.6kJ/kg），加热蒸汽温度为110℃（该饱和温度下水的蒸发潜热r=2232k J/kg）。由于溶液很稀，假设溶液的沸点和水的沸点相同，0.04MPa下水的沸点为75.4℃，料液的比热近似于水的比热，Ｃｐ＝4.174kJ/kg•K。&　　（1）求蒸发量、浓缩液量、加热蒸汽量和加热室的传热系数K。&　　（2）如进料量增加为12000kg/h，传热系数、加热蒸汽压强、蒸发室压强、进料温度和浓度均不变的情况下，蒸发量、浓缩液量和浓缩液浓度又为多少？均不考虑热损失。（10分）&&&　　4、某吸收塔填料层高4m，用水吸收尾气中的有害成分A。在此情况下，测得的浓度如图所示。已知平衡关系为Y=1.5X。求&　　（1）气相总传质单元高度；&　　（2）操作液气比为最小液气比的多少倍？&　　（3）由于法定排放浓度规定ｙ(2)必须小于0.002，所以拟将填料层加高。若液气比不变，问填料层应加高多少？&　　（4）画出填料加高前后吸收操作线的示意图。（15分）&&　　5、苯、甲苯两组分混合物进行常压蒸馏，原料组成X(苯)＝0.7，要求得到组成为0.8的塔顶产品（以上均为摩尔分率），现用以下三种方法操作：&　　（1）连续平衡蒸馏；&　　（2）简单蒸馏（微分蒸馏）；&　　（3）连续蒸馏。&&　　在（3）情况下，塔顶用一分凝器，其中50%的蒸汽冷凝返回塔顶。出冷凝器的蒸汽与冷凝液体呈平衡。对每种方法进料量均为100kmol/h，问塔顶、塔釜产量各为多少？汽化量为多少？已知α=2.46。（15分）&&　　6、在常压连续干燥器中将处理量为0.417kg/s的湿物料自含水量为47%干燥到5%（均为湿基），采用废气循环操作，新鲜空气与废气混合后经预热器加热，再送入干燥器。循环比（废气中绝干空气质量与混合气中绝干空气质量之比）为0.8。新鲜空气的湿度Ｈo为0.0116kg/kg绝干气，温度为22℃，废气的湿度Ｈ2为0.0789kg/kg绝干气，温度为52℃。假设干燥过程为绝热过程，预热气的热损失可忽略不计。试计算干燥过程的耗热量，并在Ｈ-Ｉ图上定性画出湿空气的状态变化情况。（10分）&已知：绝干空气比热为1.01kJ/kg•K&　　　水蒸气的比热为1.88kJ/kg•K&　　　0℃时水蒸汽潜热为2490kJ/kg
清华大学1998年研究生入学考试：物理化学试题&&&&　　试题内容：&&　　一、填空题（每空2分、共24分）&&　　1、1mol理想气体经节流膨胀（即Joule-Tomson实验）压力自Ｐ1降低到Ｐ2，此过程的△Ａ________0，△Ｕ______0 。（填&，=或&）&&　　2、298K时，HCl(g)的标准摩尔生成焓△fＨm=-92.31kJ/mol ,HCl(g)的无限稀释摩尔溶解焓（即1molHCl(g)溶于水形成无限稀薄溶液时的△H）为-75.13kJ/mol。若以b=ｂ(θ)但仍遵守亨利定律的溶液作标准态，则HCl(aq)的标准摩尔生成焓△fＨm（HCl,aq）=_______。&&　　3、下图为Bi-Zn二组分体系的固液平衡相图，&&　　（１）A区的平衡相态为______,&&　　　　　B区的平衡相态为________。&&　　（２）527K时，纯Bi(s)和含93%Bi（质量百分数）的溶液成相平衡。若以纯Bi(s)作标准态，则上述溶液中Bi的活度为_________，活度系数为__________。（Bi和Zn的相对原子质量分别为209和65.39）&&&&　　4、某原子基态与第一激发态的能级是非简并的，第一激发态的简并度为3，若其他能级可被忽略，且以基态作为能量的零点，298K时，此原子的电子配分函数ｑe=______。当体系平衡时，在此二能级上的粒子数之比Ｎ2／Ｎ1=___________。（玻尔兹曼常数k=１.３８×１０-23Ｊ／Ｋ）。&&　　5、对大多数纯物质的液体来说，当温度升高时，其表面张力__________。&&　　6、实验测得反应2A+B=C+D的速率方程式为r=ｋ1[A][A][B]，若反应物的起始浓度为[Ａ]0=2[Ｂ]0，则速率方程式可写为：ｒ＝ｋ2[Ａ][Ａ][Ａ]，ｋ1与ｋ2的关系为ｋ1＝________ｋ2。&&　　7、在电池_____________________________中进行的反应是Ｎｉ(s)＋Ｈ2Ｏ(l)→ＮｉＯ(s)＋Ｈ2(g)&&&　　二、选择填空题：（每题2分，共12分）&&　　1、若理想气体反应Ｏ＝∑νBＢ在Ｔ1～Ｔ2的温度区间内，各物质均无相变，且△Ｃｐ&0（△Ｃｐ＝∑νBＣｐ,B），则在此温度区间内，反应摩尔焓变△ｒＨｍ随温度升高而（　　　）。&&　　（ａ）增大　　（ｂ）减小　　（ｃ）不变　　（ｄ）无法确定其变化&&　　2、某纯物质的液体凝固时，液体的密度大于固体的密度，则该液体的凝固点随压力升高而（　　　）。&&　　（ａ）升高　　（ｂ）降低　　（ｃ）不变　　（ｄ）不能确定其变化&&　　3、对于组成不变的均相封闭体系，在ｗ'＝0的条件下，＝（　　　）&&　　（ａ）　　（ｂ）　　（ｃ）　　（ｄ）&&　　4、在浓差电池中，电池的电动势是Ｅ，液接电动势是Ｅｊ，则（　　　）&&　　（ａ）Ｅ&０,Ｅｊ&０　　（ｂ）Ｅ&０,Ｅｊ&０&&　　（ｃ）Ｅ&０,Ｅｊ&０　　（ｄ）Ｅ&０,Ｅｊ&０&&　　5、平行反应中，ｋ1＝10/min，ｋ2＝20/min，在反应过程中产物Ｂ和Ｃ的浓度之比，［Ｂ］/［Ｃ］＝（　　　）&&　　（ａ）１　　　（ｂ）２　　　（ｃ）０.５　　（ｄ）无法确定其变化&&　　6、当反应ＣａＣＯ3(s)＝ＣａＯ(S)＋ＣＯ2(g)在某给定条件下达到平衡时，若保持其他反应条件不变，而将ＣａＣＯ3(s)的颗粒变小，平衡将（　　　）。&&　　（ａ）向左移动　　　（ｂ）向右移动　　　（ｃ）不移动&&　　（ｄ）不能确定其移动方向&&&　　三、计算题：&&　　1、在熔点附近的温度范围内，ＴａＢｒ5固体的蒸气压与温度的关系为：　　lg(p/kPa)=1.696-5650/T;&&　　液体的蒸气压与温度的关系为：　　lg(p/kPa)=7.296-3265/T。&&　　试求ＴａＢｒ5三相点时的摩尔蒸发焓及摩尔熔化焓。（12分）&&　　2、在1000℃时，将4.4克ＣＯ2(g)充入一放有过量碳的容积为1立方厘米体积的容器中，发生下述反应，ＣＯ2(g)＋Ｃ(s)＝2ＣＯ(g)&&　　当反应达平衡时，混合气体的平均摩尔质量为36g/mol。&&　　(1)计算此反应在1000℃时的Ｋ及容器中的平衡压力。&&　　(2)当反应达平衡时，充入一些Ｈｅ(g)，使反应压力增加一倍，求当反应重新达平衡时ＣＯ(g)的质量。&&　　(3)如果当反应温度升高10℃时，Ｋ的值增加一倍，求此反应的△Ｈｍ和△Ｓｍ（假设△Ｃｐ＝０）。（14分）&&　　3、电池&&　　(1)写出此电池的电极与电池反应；&&　　(2)已知298Ｋ时，ＰｂＳＯ4的容度积Ｋφ＝1.67×10e-8，&&　　(3)当此电池在端电压为1Ｖ的情况下，不可逆放电96500Ｃ时，电池反应热为-151.61kJ，计算电池中硫酸根离子的活度ａ1。已知（эＥ／эＴ）ｐ＝－4.9×10e-4Ｖ/Ｋ。（14分）&&　　4、当一气相反应2Ａ──→Ｐ在一密闭容器中进行时，实验测得反应器内气体的总压随时间的变化如下：&&t/s 0 100 200 300 400 &p/kPa 53.5 42.9 38.4 35.7 34.1 &&&　　（1）求此反应的级数和速率系数&&　　（2）当反应物消耗掉60%时需多少时间？（14分）&&　　5、（1）20℃时将半径为5×10e-5m的毛细管插入盛有汞的容器中，在毛细管内的汞面下降高度为11.10cm。若汞与毛细管壁的接触角为140°。汞的密度为1.36×10e4千克每立方米，求汞的表面张力。&&　　（2）若20℃时水的表面张力为0.0728Ｎ/ｍ，汞-水的界面张力为0.375Ｎ/ｍ。试判断水能否在汞的表面铺展开？（10分）
1. 在呼吸链中阻断电子从辅酶Ｑ向细胞色素C传递的抑制剂是:&&A&&&&&&&&&&&(a) 抗霉素A&&(b) 安密妥&& (c) 鱼藤酮&&(d) 氰化物&2. 下列哪个化合物是氨基转移酶的辅酶&& B&&&&&&&&&&&&& (a) 生物素&&&&&&&&&&&&(b) 磷酸吡哆醛&&&&&&&&&&&&& (c) NADH&&&&&&&&&&&&&&(d) 黄素单核苷酸 3. 两分子丙酮酸转变成一分子葡萄糖时需消耗几个高能磷酸键&&A&&&&&&&&&&&&&&&(a) 6个&&&&&&&&(b) 4个&&&&&& (c) 8个&&&&&&&&(d) 12个&4. mRNA的ACG密码子相对应的tRNA的反密码子是:&&B&&&&&&&&&&&&&&& (a) TGC&&&& (b) UGC&&&&(c)CGU&&&&(d) CGT&5. 被人类所排泄的嘌呤代谢的最终产物是下列中的哪一种&& C&&&&&&&&&&&&&&& (a) 尿囊酸&&&&(b) 乳清酸&&&&(c) 尿素&& (d) 尿酸 &6. 下列那一种酶在酵解和糖异生中都起作用&& A&&&&&&&&&&&&&&&(a) 丙酮酸激酶&&&&&&&&&&&&(b) 3-磷酸甘油醛脱氢酶&&&&&&&&&&&&&&&(c) 丙酮酸羧化酶&&&&&&&&&&(d) 果糖-1,6-二磷酸酶&7. TCA循环首先是由谁发现和提出耒的&& C&&&&&&&&&&&&&&&&&(a) Leuis Pasteur&&&&&&&&&&&& (b) Avery and McCarty&&&&&&&&&&&&&&&&&(c) Hans Krebs&&&&&&&&&&&&&&&&(d) Fred Sanger&8. 对一个米氏酶来讲,当Km值等于0.2[S]时,其反应初速度v等于&& A&&&&&&&&&&&(a) 5/6Vmax&& (b) 11/12Vmax&& (c) 1/6Vmax&& (d) 1/4Vmax&9. 下列哪一种糖溶液不能使平面偏振光发生偏转.&& D&&&&&&&&&&&&&&&&&(a) α-D葡萄糖&&&&&&&&&&&& (b) 磷酸二羟基丙酮&&&&&&&&&&&&&&&&&(c) D-甘油醛&&&&&&&&&&&&&& (d) 二羟基丙酮&10. 谷氨酸的pK1(-COOH)=2.19&& pK2 (-NH3+)=9.67&&&&A&&&&&&&&&&&&&&&&&&&pK R(R group)=4.25.那么它的pI值应为:&&&&&&&&&&&(a) 3.22&&&&&&(b) 2.97&&&&&&(c) 5.41&&&&&&(d) 5.93&11. tRNA的3’-未端都是有一个共同的结构,下列哪一个是对的.&& B&&&&&&&&&&&(a) -G-G-A-OH&&&&&&&&&&(b) -C-C-A-OH &&&&&&&&&&&(c) -A-C-C-OH&&&&&&&&&&(d) -A-A-A-OH&12. 下列那一个蛋白质二级结构全部为β-折叠构象.&&C&&&&&&&&&&&(a)纤维蛋白&&(b) 胶原蛋白&&(c) 丝心蛋白&&(d) 毛发中的角蛋白&13. 软脂酸生物合成过程中酰基的载体是:&& B&&&&&&&&&&&(a) CoA-SH&&&&&&(b) ACP&&&&&&(c) 肉毒碱&&&&&& (d) ATP&14. 天门冬氨酸转氨甲酰基酶是一个别构酶,它强烈地被其终端产物所抑制,下列化合物中哪一个是这种抑制剂:&& C&&&&&&&&&&&(a) ATP&&&&&&&& (b) UTP&&&&&&(c) CTP&&&&&&&&&&(d) AMP&15. 线粒体氧化磷酸化反应的典型的解偶联剂是:&& B&&&&&&&&&&&(a) 寡酶素&&&&&&&&&&&&&&&&&&(b) 2,4-二硝基苯酚&&&&&&&&&&&(c) 对氨基苯甲酸&&&&&&&&&&&&(d) 氰化钾
北京大学生物系1999年生物化学试题 &一． 名词解释&米氏常数（Km）磷酸戊糖途径 调节子 酶辅助因子 cori循环与巴斯德效应 滚动环复制 &二． 结构式&TPCK 尼克酰胺 GC配对 IP3&三． 填空&1, 蔗糖是否为还原糖-----。&2，糖苷键的两种类型-----和-----。&3，DNA的一条链序列为GTCAATG，那么另一条链的序列为-----。&4，-----常数表征酶的催化效率。&5，ρ因子的催化活性是-----和-----。&6，常见的遗传缺陷病有-----，-----，-----，-----；常见的放射性标记的同位素是-&----&，-----，&-----，-----。&7，DNA复制过程中动物是以-----为能源，E. Coli 以-----为能源。&8，生物体中产能最多的生化反应过程是-----。&9，-----发现TCA循环，-----发现化学渗透学说。&10，真核生物rRNA拼接过程中左端的拼接点顺序为-----右端为-----，切除-----结构。 &11，生长激素是由-----产生的。&12，E．Coli DNA Pol I 经酶切，得到大小片段，其中大片段具有-----酶活性和-----&酶活&性，&小片段具有-----酶活性。&13，必需脂肪酸有-----和-----。&四． 回答&1， 作动力学曲线区分酶的可逆性抑制与不可逆抑制？&2， 比较ATP与ppi在磷酸键及生物学功能方面的异同。&3， 真核生物至少需要31种tRNA才能识别61种密码子，而线粒体中tRNA只有22种，为什&么？&4， 阐明衰减子对操纵子的调控。&5， 糖酵解和糖异生过程中涉及的不可逆反应和限速步骤。&五． 计算&1， 反竟争抑制和米氏方程。&2， 酶活力，比活力，酶浓度。&3， DNA半保留复制。15NDNA在14N培养基上培养一代后，14NDNA与14N-15NDNA杂交分子&之比&是多少？&4， 正常DNA的超螺旋密度为-0.05，在无拓扑异构酶条件下当复制到超螺旋密度为0.07&时，&由于正超螺旋的阻力而不能继续复制，求此时的复制百分数。&5， 2ADP===ATP+AMP&已知[ADP] [AMP] [ATP]&求：1，该反应的能荷。&2，Keq（各浓度为平衡态浓度）。&一， 名词解释 &中等纤维 核孔复合体 间隙连接 细胞癌基因 细胞全能性 端粒 &二， 填空 &1， 最早原核细胞产生于----年前。 &2， 电镜分辨率比普通光镜分辨率高----倍。 &3， 细胞质膜的最显著特性是----和----。 &4， 细胞外基质中含量最高起支架作用的蛋白是----。 &5， 细胞周期中的引擎是----和----。 &6， 膜蛋白与酶的动力学曲线相同，其最显著的差别是----。 &7， 高尔基体修饰蛋白的过程中，糖基化修饰发生在----面，分泌泡在----面。 &8， 动物鞭毛与细菌鞭毛的最主要区别----。 &9， 研究染色体上特异DNA序列进行分析的方法是----。 &10，氧化磷酸化主要发生在----和----。 &三， 问答 &1，细胞程序化死亡的显著特点及其生物学意义。 &2，什么是Hayflick界限，什么是端粒，两者关系如何。 &3，细胞信号传导的机制有哪几种，其中哪些与肿瘤细胞发生有关。 &4，用秋水仙素处理动物细胞，细胞内质网与高尔基体分布有什么改变，为什么？ &5，绘图并简要说明细胞内新蛋白质的合成转运途径。
2009年考博英语---清华大学模拟试题 &&Part II&& Vocabulary&21. All the students in this university are requested to comply with the regulations.&&&&&A. required&&&&&B. demanded&&&&&C. ordered&&&&&D. expected&22. Individuals have applied “positive thinking” either to particular external circumstances or to some particular habit or character defect.&&&&&A. used…for…for&&&&&B. employed…upon…upon&&&&&C. adapted…to…to&&&&&D. suited…to…to&23. Everyone who heard the story found it incredible&&&&&A. irresistible&&&&&B. immaterial&&&&&C. unbelievable&&&&&D. nonsensical&24. They conceded that her statement was true.&&&&&A. proved&&&&&B. doubled&&&&&C. denied&&&&&D. admitted&25. Absent impartiality on the part of the psychotherapist, a patient’s conflicts may be exacerbated.&&&&&A. indifference&&&&&B. objectivity&&&&&C. voiced concern&&&&&D. engagement&26. I was extremely exasperated when I saw that my room was littered with wood shavings.&&&&&A. startled&&&&&B. exalted&&&&&C. rapturous&&&&&D. irritated&27. If that is what he said, his reasoning must be fallacious.&&&&&A. faulty&&&&&B. fascinating&&&&&C. fastidious&&&&&D. fantastic&28. They awoke to find the maid had left the remnants of dinner on the table.&&&&&A. list of items for&&&&&B. invitations to&&&&&C. leftovers of&&&&&D. preparations for&29. Some would consider that an infringement of good manners whereas others would not.&&&&&A. an example &&&&&B. a violation&&&&&C. a problem&&&&&D. an indication&30. The report was unusual in that it insinuated corruption on the part of minister.&&&&&A. denied&&&&&B. suggested&&&&&C. proposed&&&&&D. stated&31. Current data suggest that although ______ states between fear and aggression exist, fear and aggression are as distinct physiologically as they are psychologically.&&&&&A. simultaneous&&&&&B. serious&&&&&C. partial&&&&&D. transitional&32. Are we going to see an end to the Arab-Israeli ______.&&&&&A. disaster&&&&&B. controversy&&&&&C. confrontation&&&&&D. aggression&33. He
he ought to ______ it days ago.&&&&&A. have written&&&&&B. write&&&&&C. had written&&&&&D. be writing&&&34. The government requires that a census be taken every five years so that accurate statistics may be ______.&&&&&A. composed&&&&&B. complemented&&&&&C. completed&&&&&D. compiled&35. I was not alone in my knowledge, the woman had also seen my father’s eyes gleaming with ______ pride.&&&&&A. contracted&&&&&B. contested&&&&&C. contented&&&&&D. contrasted&36. Industry ______ only ten percent of the smog in Los Angeles.&&&&&A. calls on&&&&&B. mounts to&&&&&C. appeals to&&&&&D. accounts for&37. I let my children make their own decision I wouldn’t ______ to interfere.&&&&&A. presume&&&&&B. resume&&&&&C. assume&&&&&D. consume&38. The minister’s ______ answer led to an outcry from the Opposition.&&&&&A. impressive&&&&&B. evasive&&&&&C. intensive&&&&&D. abusive&39. The first two assumptions made about the ______ of TV were dead wrong: that it would bury radio and it would be a threat to movies.&&&&&A. recession&&&&&B. advent&&&&&C. diversity&&&&&D. bias&40. The novel, which is a work of art, exists not by its ______ life, but by its immeasurable difference from life.&&&&&A. significance in&&&&&B. imagination at&&&&&C. resemblance to&&&&&D. predominance over&&&&Part III&& Reading Comprehension&一、&&&&&&& Britain and Spain have the highest proportion of cocaine users in the EU, according to a pan-European drugs survey published today. The European Monitoring Center for Drugs and Drug Addiction 2004 report found 2% of all adults in the UK and Spain reported recent cocaine use, close to figures for the US, compared to less than 1% across the EU as a whole.&&&&&&& It reported that cocaine use was increasing in Denmark and Germany and that more Europeans were seeking treatment for cocaine-related problems. In most countries, treatment is demanded for the use of cocaine powder rather than smoked crack cocaine—but in the Netherlands around two-thirds of cocaine treatment demands were crack related.&&&&&&& Crack use was increasing in a number of cities in Germany, Spain, France and the UK, the survey found.&&&&&&& Heroin use is relatively stable in many EU countries, with new users failing, but limited data from the new member states in central and Eastern Europe may localized increases.&&&&&&& Deep concern surrounds the continuing HIV epidemic in some of the new EU member stats and their bordering countries, where heroin injecting is more common than it is the western states. Estonia, Latvia, Russia and Ukraine are the countries with the fastest growing HIV epidemic in the world, though there are signs it is stabilizing in the Baltic states.&&&&&&& The director of the EU drugs agency, Georges Estievenart, identified positive signs in the downwards trend of drug-related deaths and better access to treatment and care but warned of future problems.&&&&&&& “There is a risk that some of these positive trends may be short-lived and real concerns surround potential drug epidemics, particularly in some of the new members of our Union.”&&&&&&& “And we should not forget that drug use in general remains at historically high levels—many countries are reporting rising cocaine use and more people are using cannabis and ecstasy in parts of Europe.”&&&&&&& The Home Office minister, Caroline Flint, said the report was based ion old data and the British Crime Survey showed that crack and cocaine use bad stabilized.&&&&&&& “We are not complacent about the drugs situation in Britain,” she said, “Drug use is still too high and we are planning new legislation aimed at getting more users into treatment—including testing on arrest—and strengthening police powers to tackle drug dealers.”&41. Which of the following countries has the highest proportion of cocaine users?&A. Britain.&B. Spain.&C. the US&D. Denmark.&42. Which of the following can not be found in the survey?&A. Crack use was increasing in a number of cities in Germany, Spain, France and the UK.&B. In most countries, treatment is demanded for the use of crack cocaine.&C. In central and eastern Europe the number of Heroin use is increasing.&D. There may be a deep connection between HIV epidemic and Heroin use.&43. Why does HIV epidemic in some of the new EU member states and their bording countries keep growing?&A. In these countries heroin injecting is more common.&B. People in these countries are not always seeking treatment for cocaine-ralated problems.&C. People in these countries like to use crack rather than heroin.&D. These countries are poorer than their western neighbors and can not provide adequate healthcare.&44. What can we read from Georges Estievenart’s warning?&A. Drug use in general remains at historically high levels, especially in eastern European countries.&B. Most people are using cannabis and ecstasy in parts of Europe.&C. There is a risk that some of these positive trends may be short-lived.&D. The drug situation in some countries is actually not very satisfactory because of the old data.&45. This passage mainly talks about ______?&A. The drug situation in EU as a whole and in some countries specifically.&B. The reason why Britain and Spain have the highest proportion of cocaine users in the EU.&C. The connection between HIV epidemic and heroin injecting.&D. The future steps the EU will take to reduce the rate of drug use.& &二、&&&&&&& Thailand confirmed three new human bird flu cases Thursday as healthy officials warned it could take two years to conquer Asia’s outbreak. Meanwhile, the World Health Organization said the latest tests show no sign of a killer hybrid virus that could easily pass between people.&&&&&&& Tests on a cluster of bird flu cases in a Vietnamese family showed there was no mixing of genes between the bird flu strain and human flu, according to WHO.&&&&&&& In the United States, a strain of bird flu was found at four live chicken markets in northern New Jersey, just days after outbreaks at two farms in Delaware led to the destruction of thousands of birds. &&&&&&& WHO has said the best way to control the spread of the disease is by culling the birds. In Asia, tens of millions of chickens have been killed by infecting or slaughtered in containment efforts as bird flu spread, jumping to people in Vietnam and Thailand.&&&&&&& The human death toll stood at 19 on Thursday.&&&&&&& While two of the three people labeled as new cases in Thailand have recovered, the third, a 13-yearo-old boys, was in intensive care in northeastern Chaiyaphum province, Thai officials said.&&&&&&& Fears of an outbreak prompted Singapore, believed free of bird flu, to announce plans to euthanize 5,000 healthy chickens in a drill to prepare for any possible infection.&&&&&&& Ten governments in the region have dealt with the disease over the past couple of months, with China boosting its culling efforts as reports of infections there increased.&&&&&&& Beijing said Thursday it was mobilizing 16,000 workers for anti-bird flu efforts in a province bordering Vietnam where China’s first bird flu case of the season was confirmed in late January. Among their tasks is to try to pinpoint the source of the first infection.&&&&&&& Destroying infected fowl is the best way to contain the outbreak, according to WHO.&&&&&&& Thai officials have said slaughters of more than 26 million chickens have brought the disease largely under control there, while Vietnam has said its outbreak is easing. In Pakistan, U. N. officials said the disease has been contained. But the U. N. Food and Agriculture Organization said it would take much longer to bring the region outbreak under control.&&&&&&& “I would have though that we’d be looking at a period of six months… but it could be as long as two years,” FAO animal health officer Peter Roeder said in Geneva. In New Jersey, state veterinarian Nancy Halpern said the markers likely got the virus from one of their many farms and distributors. New Jersey has about 35 live chicken markets.&46. Which of the following is true according to WHO?&A. It could take two years to conquer Asia’s outbreak of bird flu.&B. The bird flu is dangerous because it is very easy to spread between people.&C. The best way to control the spread of the bird flu is by killing the infected birds.&D. The outbreak of bird flu is hard to control because the genes of the bird flu areain and human flu are mixing very quickly.&47. Which one of the following countries has not been infected with human bird flu?&A. Singapore.&B. Thailand.&C. China.&D. Pakistan&48. According to the passage, which one of the following countries has not announced the containment of bird flu?&A. Pakistan.&B. Thailand.&C. Vietnam.&D. the United States.&49. Which of the following is false according to the passage?&A. Three new cases of human bird flu have been confirmed by Thailand until Thursday.&B. Two of the three patients in Thailand have recovered while the other died.&C. The best way to control the bird flu is to slaughter infected fowl.&D. The spread of bird flu may last as long as two years, while six months as least.&50. This passage is most likely to come from ______.&A. a piece of news&B. a science book&C. a survey by WHO&D. a report by FAO& &三、&&&&&&& Despite ongoing negotiations with its unions, United Airlines has told the bankruptcy court that the “likely result” will be a decision to terminate all of its pension plans.&That would precipitate the biggest pension default in history, more than twice the size of the Bethlehem Steel Corporation default in 2002. The move is expected to destabilize the already struggling airline industry, prompting other old-line carriers like Delta to eventually follow suit to maintain competitiveness.& It would also put additional pressure on the Pension Benefit Guaranty Corporation (PBGC), the federal agency that insures traditional pensions in case companies go belly up. It’s already facing more than a ＄9 billion shortfall. A default by United would saddle it with an additional ＄8.4 billion in unfunded obligations. If other airlines follow, the PBGC may have to go to Congress and plead for a bailout that some experts say would be bigger than the Saving and Loan debacle of the 1980s.&&&&&&& More broadly, what all this means is that retirement for US workers just isn’t what it used to be. Forget the gold watch and reliable pension check after 30 years of service. The impact of globalization and competition from low-wage companies that don’t provide benefits has shifted the onus of retirement security from larger firms onto individuals.&&&&&&& Twenty years ago, 40 percent of American workers were covered by traditional pensions known as defined-benefit plans. Today that number’s dropped to 20 percent. As the Bethlehem Steel and United examples show, even that 20 percent may not be able to count on what they’ve been promised. Currently, about 75 percent of those corporate plazas are underfunded. “There are numerous threats to retirement in the future,” says Brad Belt, executive director of the PBGC. “So it’s incumbent on individuals to be well informed, prudent about their investment and to save accordingly.”&&&&&&& To get a sense of the impact of the pension crisis on individuals, look at what United employees can expect. Pilots, who by law must retire at 60, could see their retirement income cut by 75 percent.&&&&&&& Betty, who asked that her name not be used, has been flying for United for 26 years, She was expecting to retire with ＄140,000 a year. After the recent round of give-backs, that was cut to ＄90,000. But of United defaults as expected, she’d receive only ＄28,000 from the PBGC. If she waits until 65 to start collecting, she could be eligible for as much ＄44,500 a year.&&&&&&& Either way, once pilots are forced to leave the cockpit at 60, most will probably look for another job rather than lounge on the golf course. Betty has already started a mediation business on the side. “All of the benefits that I’d been promised during those 26 years have been erased by corporate American greed,” she says. “And yet I can see the big picture. I’ve said for three years that our pensions are history. No matter how many promise they make us, if the money isn’t there, it isn’t there.”&&&&&&& For the pilot union, which negotiated the pension benefits over the years, often giving up wage increases for better retirement package, the current situation is infuriating. They see pensions as benefits that are earned, like employee paychecks, not a bonus to be given as long as a company can afford it. “It seems immoral that just because they happen to be in a legal situation, they can walk away from those obligations,” says Steve Derebey, spokesman for Air Line Pilots Association. “Why this isn’t a burning, blazing campaign issue is beyond me.”&51. Which of the following conclusions is not compatible with the main ideas of the article?&A. The trouble that the airline industry faces id due to the impact of globalization and competition from low-wage companies.&B. Retirement for US workers just id not what it used to be.&C. The dispute over United’s pension has become a burning, blazing campaign issue.&D. There are numerous threats to retirement in the future.&52. “Either way, once pilots are forced to leave the cockpit at 60, most will probably look for another job rather than lounge on the golf course. ” In the 8th paragraph, this sentence means that ______.&A. those pilots’ pensions have been severely cut back&B. they prefer working to idling after retirement&C. the pensions originally promised to those pilots were not enough for a luxurious life after their retirement&D. after their retirement, those pilots are forced to continue their work&53. Which of the following is not suggested by the author as far as getting better prepared for retirement is concerned?&A. It’s incumbent on individuals to be well informed, prudent about their investments, and to save accordingly.&B. To pleas for social support against corporate greed.&C. To start another job on the side.&D. To see the big picture and help yourself.&54. Why has the onus of retirement security been shifted from larger firms onto individuals? Pick an explanation.&A. Corporate greed.&B. Immorality.&C. Corporate defined-benefit plans are underfunded.&D. To maintain corporate competitiveness.&55. The general tone of the author in presenting the subject is ______/&A. infuriating&B. partial&C. personal&D. realistic& &四、&&&&&&& In every major city in America, commuters are spending more and more time in their cars fighting traffic. The Texas Transportation Institute recently reported that the average commuter spends an extra 46 hours—more than a full workweek—each year caught in traffic.&&&&&&& A major source of the congestion is freight trucks. One large truck takes up the space of almost four cars, and the average truck is becoming longer, with more use of double-and triple-trailers. Increases in truck volume, obviously, add to commuting problems, and according to the U.S. Department of Transportation, freight volunme is expected to increase by two-thirds over the next 20 years.&&&&&&& One proposed solution&—building new roads—is expensive and politically contentious. But there’s another way: greater use of freight rail.&&&&&&& In an urban area like New York, shifting 25% of freight from trucks to freight trains by the year 2025 would reduce drivers’ commuting time by 52.9 hours. In addition, such a shift would save ＄734 per household in annual congestion costs.&&&&&&& Shifting freight from road to rail also helps the environment. Freight rail is more fuel-efficient per ton-mile than trucks. And it reduces drivers’ fuel consumption by decreasing the time the spend idling in traffic. By 2025, commuters in New York could save 254 gallons of fuel with a 25% shift of freight from truck to rail.&&&&&&& Air pollution levels also would improve with an increase in the use of freight rail. For instance, that same 25% shift to rail by 2025 would decrease air pollutants New York by as much as 79,500 tons.&&&&&&& To carry out these changes, the freight tail industry will need more capacity, but that depends on investments. Because railroads are not meeting their cost of capital, government policymakers may want to consider investment incentives to help meet the growing demand for freight rail. This would enable freight railroads to provide convenient, on-time, quality service to shippers and boost their share of freight transport.&&&&&&& It is hard to imagine a less costly or more effective strategy for reducing traffic congestion.&56. In the 2nd paragraph, the basic problem with the freight rail industry is that ______.&A. it only has a very low capacity&B. the price of its service is too low&C. its services are not very convenient&D. it is not a profitable enough business&57. According to the author’s advice, how should the problem with the freight rail industry be solved?&A. The government should offer some investment incentives.&B. The freight rail industry should increase its capacity.&C. The freight tail industry should provide convenient, on-time, quality service.&D. None of the above-mentioned.&58. According to the article, all of the following are true except that ______.&A. air pollution levels would improve with an increase in the use of freight rail&B. the author’s suggestion is the least costly or most effective strategy for reducing traffic congestion&C. more capacity of the freight rail industry means more return on investments&D. investment incentives can help increase the capacity of the freight rail industry&59. According to the article, in comparison with freight trucks, freight rail has all of the following advantages except that ______?&A. it’s more fuel-efficient per ton-mile&B. it produces less air pollutants&C. it’s more convenient&D. it can help relieve road traffic congestion&60. The tone of the passage seems to be ______.&A. persuasive&B. absolute&C. exaggerating&D. argumentative& &Part IV&& Cloze&&&&&&& National Geographic&& 61&& fill a number of roles, says Karen Kasmauski. “We are journalists, researcher, thinkers,” she says, “photography is our&& 62&& .”&&&&&&& As one of the Society’s six contributing phptpgraphers-in-residence, Karen seeks to focus&& 63&& attention on global changes and how they&& 64&& human health. One promising&& 65&& is the anti-measles&& 66&&&&in Kenya led by the American Red Cross, the Center for Disease Control and Prevention, and UN&& 67&& .&&&&&&& “These photographers-in-residence have chosen subject they’ve been&& 68&& for years, subjects they’ve&& 69&& about,” says program manager Charlene Valeri. Frans Lanting investigates&& 70&& and the danger of&&&&71&& loss to animals I the wild. David Coubilet works to promote the survival of coral reef&& 72&& in the South Pacific. Sam Abell&& 73&& North American rivers from a cultural, historical, and ecological&& 74&& . Underwater photography Emory Kristof will use&& 75&& -operated vehicles to take inventory of deep ocean&& 76&& in water off Indonesia. Annie Griffiths Belt is promoting&& 77&& of wilderness areas in North America, both in and outside of classrooms. By speaking to&& 78&& and displaying their work widely, the photographers hope to&& 79&& public support for the Society’s&& 80&&.& &61.&&&&&&&&&&&& & A. contributors& B. photographers& C. columnists& D. writers& &62.& A. instrument&&&&&&&&&&&&&&&&&&&&&& & B. device& C. tool& D. utensil& &63.& A. personal&&&&&&&&&&&&&&&&&&&&&& & B. private& C. particular& D. public& &64.& A. affect&&&&&&&&&&&&&&&&&&&&&&&&&& & B. sway& C. persuade& D. impress& &65.& A. determination&&&&&&&&&&&&&&&& & B. initiative& C. movement& D. enterprise& &66.& A. cause&&&&&&&&&&&&&&&&&&&&&&&& & B. crusade& C. campaign& D. strategy& &67.& A. operations&&&&&&&&&&&&&&&&&&&&&& & B. agencies & C. offices& D. managements& &68.& A. containing&&&&&&&&&&&&&&&&&&& B. concealing& C. comprising& D. covering& &69.& A. amorous&&&&&&&&&&&&&&&&&&&&&&& B. desirous& C. passionate& D. sympathetic& &70.& A. convention&&&&&&&&&&&&&&&&& B. conversation& C. sustenance& D. protection& &71.& A. habitat&&&&&&&&&&&&&&&&&&&&&&&&& B. residence& C. dwelling& D. occupation& &72.& A. community&&&&&&&&&&&&&&&&& B. environment& C. ecosystem& D. colony& &73.& A. inputs&&&&&&&&&&&&&&&&&&&&&&&& & B. documents& C. bears& D. justifies& &74.& A. dimension&&&&&&&&&&&&&&&&&&&&&&&&& B. point& C. technique& D. perspective& &75.& A. distantly&&&&&&&&&&&&&&&&&&&&&&& B. separately& C. remotely& D. exclusively& &76.& A. variety&&&&&&&&&&&&&&&&&&&&&&&& & B. species& C. categories& D. division& &77.& A. preservation&&&&&&&&&&&&&& & B. maintenance& C. reservation& D. conversation& &78.& A. attendants&&&&&&&&&&&&&&&&&&&&&&& B. audiences& C. activists& D. attendees& &79.& A. speed&&&&&&&&&&&&&&&&&&&&& B. launch& C. mobilize&&& D. ignite& &80.& A. errand&&&&&&&&&&&&&&&&&&&&&&&& & B. chore& C. assignment& D. mission& & &Part V&& Writing&Directions: In this part, you are asked to write a composition on the title of How to Copy Effectively with the Stress in Life. as far as your own experience with the problem. Your composition should be no less than 200 English words. Put your composition on the ANSWER SHEET. & & &参考答案与解析& &Part II Vocabulary&21. A&require 意思是“请求，要求”，与request 的意思相同。 但request 含有“礼貌地请求”之意。demand 也有“要求，需要”的意思， 但是指坚决、强硬得要求，往往带有命令的口吻。&22. A&use … for 是“运用，应用”之意，与apply…to意思相同。&23. C&unbelievable 不可信，不能令人相信的；irresistible不能抵抗的，制服不了的； immaterial 不重要的，不足取的；nonsensical 无意义的，荒谬的，无条理的。&24. D&&&&&&& admit“允许承认”，与划线词concede的意思相近。&25. B&&&&&&& impartiality不偏不倚，公正，公平。四个选项中：indifference 不关心；objectivity 客观性；vioced concern 表示出的关注；engagement 约会，婚约。&26. D&&&&&&& irritated 激怒的；startled 吃惊的，吓了一跳；exalted 兴奋的，得意洋洋的，崇高的；rapturous使狂喜的。&27. A&&&&&&& fualty错误的，有缺陷的；fascinating迷人的；fastidious难以取悦的，讲究的；fantastic不合情理的，怪诞的。&28. C&&&&&&& remnants残余，残留。list of items for目录；invitations to 邀请，招待；preparations for 准备，预备。&29. B&&&&&&&&&&&&& infringemnet违反，侵害；violation 违反，违背；indication指出，迹象，暗示。&30. B&&&&&&& insinuate含沙射影地说。deny否认，拒绝；suggested 暗示；propose提议；state声明，陈迹。&31. D&&&&&&& D项的industrious“过渡的”符合题意。simultaneously 同时发生；serious严厉的，严重的；partial部分的，不公正的，都与题意不符。&32. C&&&&&&& confrontation“对抗”符合题意。Disater灾难；controversy争论；aggression侵略。&33. A&&&&&&& ought to have done sth. 意为“原本应该做某事（但却没做）”。&34. D&&&&&&& Compile“编译，编辑”符合题意。其它三项：compose组成，写作；complemente 补助，补足；complete 完成，使完善。&35. C&&&& &&&&&&& Contracted收缩的，压缩的；contest争论，为……而竞赛；contented满意的；contested形成对照的，用来修饰pride的应用contented。&36. D&&&&&&& D项account for “占，说明”符合题意。其它三项：call on 访问；amount to合计，共计；appeal to 呼吁。&37. A&&&&&&& presume“交涉，敢于，擅自行动”；resume“重头开始，恢复”；assume假定认为，担任；consume消耗。根据题意，只有A项为正确答案。&38. B&&&&&&& evasive“含糊不清的”符合题意。其他三项：impressive 印象深刻的，感人的；intensive加强的，密集的，精深的；abusive辱骂的，滥用的。&39. B&&&&&&& B项的advent“到来，出现”符合题意。其它三项：recession经济萧条；diversity不同，变化多端；bias偏见。&40. C&&&&&&& 这是一个由but连接的表转折关系的并列句，后面提到difference，所以前面应当是difference的反义词，只有resemblance to（与 …… 相似）符合题意。significance in 在 …… 之上。& &Part III&& Reading Comprehension&41. C&&&&&&& 从第一段内容可知，英国和西班牙是欧盟中使用可卡因比例最高的国家，随后在第二段中又说，英国和西班牙使用可卡因恶人数比例接近于美国（Close&to figure for the US），由此推断美国是使用可卡因比例最高的国家。&42. B&&&&&&& 第三段中讲到，大部分国家的治疗主要是针对可卡因粉末，而不是“快克”得使用（In most countries, treatment is demanded for the use of cocaine powder rather than smoked crack cocaine.）。显然选项与条差中提到的美容不相符合，因此选B。&43. A&&&&&&& 根据第六段的“Deep concern surrounds the continuing HIV epidemic in some of the new EU member states and their bordering countries, where heroin injecting is more than it is the western states.”可知艾滋病在新加入欧盟的一次而国家及其周边越来越扩散，在这些国家海洛因注射比西欧国家更普遍。其他三项都不是文中提及的相关原因，所以A项为正确答案。&44. C&&&&&&& 根据第二段的“There is a risk that some of these positive trends may be short-lived.”可知这些积极的趋势有很快消失的危险，这与C项符合。其他三项都不是警告内容。&45. A&&&&&&& 本文主要讨论了欧盟吸毒的整体形势，并具体介绍了一些国家和地区的状况。A项为文章内容最合适的概括，而其他三项都是对文章用意的曲解。&46. C&&&&&&& 选项A的内容出现在第1段，但不是来自于世界卫生组织。选项B可以排除，因为第二段中世界卫生组织说没有迹象显示很容易在人群中传播的混合致命病毒已出现（no sign of a killer hybrid virus that could easily pass between people）。选项D也可以排除，因为在第三段中，世界卫生组织说有证据表明禽流感和人类感冒的基因还没混合（there wes no mixing of genes between the bird flu strain and human flu）。第11短所述实际卫生组织的说法以及文章涉及到的一些国家控制禽流感的做法明确证实了选项C是正确的。&47. A&&&&&&& 从第8段可以看出新加坡为受到感染（believed free of bird flu），它之所以指定杀鸡计划是为了防止禽流感的爆发，而其他几个国家都是已经被感染了。因此选A。&48. D&&&&&&& 第12段中，泰国、越南和巴基斯坦得官员都已经宣布控制了本国的禽流感爆发，而文中并没有相关美国官员的话明确正是美国是否已经控制禽流感了，所以选D。&49. B&&&&&&& 对于文章开头提到得泰国新出现的3名病例，文章在第7段中说有两名已经恢复，而第3名仍在接受重症特别护理（in intensive care），并没有死亡，所以B是错误的，应当选B。&50. A&&&&&&& 本文带有明显的新闻体风格，很可能摘自一篇新闻，而没有任何证据表明它来自于一本科学书籍、世界卫生组织的调查或者是联合国粮农组织的报告。所以A项为正确答案。&51. C&&&&&&& 看最后一段，机师工会对目前的情况十分恼火。在历年的谈判中，工会往往放弃提新的要求以换取更好的退休福利待遇，可现在都成了泡影。在他们看来，退休金和工资都一样，都是他们应得的福利，并非公司额外的犒赏，没钱的时候就可以一笔勾销。公司也不能因为遇到一些法律纠纷就逃避这些他们应承担的义务，一走了之。这一问题应当在大选中成为焦点。当然，这只是机师工得看法，实际上，不选还顾不上这事，这也让很多机师工不平。&52. A &&&&&&& 本句意思是：原本这些飞行员60岁退休后可以凭借着优厚的养老金在高尔夫球场悠游自在，可现在恐怕还得找些零活以充实退休之后的生活，否则就没钱过得很滋润。由此可见，他们的退休金被消减的幅度之大。&53. B&&&&&&& 作者的建议还是提醒美国公众大的环境已改变，要认清形势（to see the big picture），认识到退休后的生活幸福与否应当有自己去把握，不要过的指望企业和政府，要认清掌握情况，明智进行投资，同时拥有充分的积蓄。结合本书中关于目前美国国内提倡的“所有权社会”的文章，可以看到美国目前的退休福利制度也在进行着较大幅度的改革。&54. D&&&&&&& 目前美国企业员工退休制度正在发生变化，主要是由于经济全球化冲击，以及国内经济管制的放松导致竞争加剧，是各企业不得不采取措施加以对应，以维持竞争力，谋求发展。所以D项为正确答案。&55. D&&&&&&& 全篇看来，作者详细分析了航空特养老金方面存在的问题，罗列了很多数据，引用了很多人的谈话，总的来说语气较客观。&56. D&&&&&&& 铁路运输业投资规模很大，但投资回报率不高，无法实现投资成本，由此导致产能不足，既缺乏投资者介入，因而政府方面考虑采取一些投资激励措施以引导更多资金流入这一行业。因而“不是十分有利可图”是铁路货运业的基本症结所在。&57. A&&&&&&& 由政府方面采取措施鼓励投资、扩大产能、降低单位或与成本，以带来更高的投资回报率是解决问题的关键。&58. C&&&&&&& 运量或产能（capacity）越大，回报或利润（return or investments）不一定越高，只有政府介入，进行一定的扶持，才能实现，否则可能规模越大，赔得越多。&59. C&&&&&&& 论方便还是公路交通运输筹划更为灵活一些。文章倒数第2段说，在政府扶持下，铁路运营企业扩大产能，可以提供更为方便、准时、质量更好得服务。&60. A&&&&&&& 文章实事求是的指出了铁路货运的问题，并提供了解决办法，引用了大量数据，目的在于以理服人。所以应选A。& &Part IV&& Cloze&61. B&&&&&&& 从上下文可以看出，《国家地理》杂志得摄影师们要扮演多种角色。&62. C&&&&&&& 对这些身兼数职的摄影师来说，摄影只是他们的工具。&63. D&&&&&&& “focus public attention on ... ”指把公众的注意力都吸引到......上来。&64. A&&&&&&& affect意为“影响”。吸引大家注意全球的变化以及这些变化如何影响人类健康。&65. B&&&&&&& initiative意为“率先公开的行动”。一项大有前途的行动就是反麻疹运动。&66. C&&&&&&& campaign意为“旨在达到一特定目的而举行的运动”，即这里所指的反麻疹运动。&67. B&&&&&&& agency意为“机构，一国政府内或国际机构管辖下的行政部门”。此处指联合国下属的部门。&68. D&&&&&&& cover这里指他们多年来各自所“涉及”得题材，他们的摄影所述及或表现的对象。&69． C&&&&&&& be passionate about... 指“对......充满热情”。他们选择了自己非常热爱的主题。&70. B&&&&&&& conversation指对自然资源的“保护”。这是Frans Lanting选择的主题&71. A&&&&&&& habitat动植物的生活环境、产地、栖息地。Frans Lanting选择的主题中还包括野生动物面临得丧失栖息地的危险。&72. C&&&&&&& ecosystem意为“生态系统”。David Coubilet积极倡导南太平洋珊瑚礁生态系统的存活。&73. B&&&&&&& document这里做动词用。表示“用文件证明”，从文化、历史、生态学的角度来证明北美的河流。&74. D&&&&&&& from a...perspective指“从...观点/角度来看”。&75. C&&&&&&& remotely-operated vehicles 指Emory Kistof 将使用“遥控的交通工具或媒介物”标识印度尼西亚的深海生物详细目录。&76. B&&&&&&& species指印度尼西亚近海的深海“生物种类”。&77. A&&&&&&& preservation指“保存，保持”。Annie Griffiths Belt 在努力促进北美野生区域的保存工作。&78. B&&&&&&& 这些摄影师向不同听众发言，广泛展示他们的工作成果。&79. C&&&&&&& mobilize指“调动，动员”。他们通过不同方式是，希望调动其公众对这个组织的支持。&80. D&&&&&&& mission指“使命”，追求一种活动或履行一种职责的内心召唤。这些摄影是把这项工作当成他们的使命。& &Part V&& Writing&&&&&&& As far as my experience with the problem of the stress in life, the effective cure for it rests with the following major steps.&&&&&&& One step is to set my priorities. Whenever I feel any undue stress is building up in my life, I tend to write down a list of things to accomplish, with the most and meanwhile allow more time than I think I’ll need for each job, with enough breathing room to handle emergencies or rearrange priorities as circumstances change. Another step is to know when to say no. My experience has led me to recognize that if we are too busy doing too many chores or too obliging to others to say no to may of their requests, we may never get around to the important activities that give us genuine satisfaction. And the most important step is to learn to ask for help. In the past, I used to seek no aid because I regarded it as a lack of ability t but now I have come to realize that there are always some parts of our life over which we have little or no control and that, by both asking for and offering help, we can strengthen personal relationship and lighten each other’s load.&&&&&&& If you feel overwhelmed with the problem of stress, therefore, you might as well try the above and may be surprised to find the same holds true for you.
2006年中国农大博士入学试题生物化学&一、名次解释（40分，每小题4分）&&&&&变构酶、蛋白质结构域、蛋白质靶向定位、复制体模型、核酶、启动子、snRNA、&SDS－PAGE、Antipoter、EST &二、问答题（60分，每小题15分）&1、真核生物与原核生物转录过程有那些差异？简述真核生物转录的主要调控环节。&2、为何说代谢调控实质上是酶活性的调控？酶水平的调控主要指那些层次上的调控，请举例说明。&3、分别举例说明酶蛋白参与物质运输、能量转换、和信号转导三种重要生命活动过程。&4、将组成型启动子控制下的GUS基因，稳定导入到某一生物体，在部分转化子中检测不到GUS活性，在另一部分转化子中虽然检测到GUS活性，但其强弱有明显差异。请予以说明。&2002年生化考题（包括名词解释、填空和简答） &1、单克隆抗体与多克隆抗体的定义、区别，是谁提出的？内容？ &2、与谷氨酸代谢有关的所有途径 &3、生糖氨基酸和生酮氨基酸生成糖的途径 &4.免疫球蛋白的种类 &5.半抗原、抗原决定簇的定义 &6.动物初乳中的免疫球蛋白 &7.酪氨酸的代谢方式和途径 &8.饥饿时三大营养物质的代谢方式、特点 &等等&2001年博士生入学考试动物生物化学试题 &1、试述血红蛋白的结构特点，血液中的氧分压、二氧化碳浓度、氢离子浓度对其与氧结合的调节作用？；血红蛋白和肌红蛋白的相同和区别？ &2、 如何保证蛋白质翻译的忠实性？ &3、 肉毒碱在脂肪代谢中的生理功能？ &4、 名词解释（16个）：如：蛋白质变性、增色效应、磷酸果糖激酶、ATP/ADP等Km值。 &5、 Trp操纵子等 &6、 转录与翻译 &7、 三种分离蛋白质的方法 &8、 脂肪、糖和蛋白质代谢的关系，说明其联系的关键酶 &9、 羊毛缩水的机制？
中国农业大学2000年博士研究生入学考试试题（生物化学）&1概念：Km、过瘤胃蛋白、遗传密码。 &2、 反刍动物蛋白质代谢。 &3、 为什么说复制比转录更精细？ &4、 血液中氨的浓度过高，动物会中毒，为什么喂牛尿素，牛不会中毒，且能正常生长？
中国农业大学1999年博士研究生入学考试试题（生物化学） &1、反刍动物蛋白质代谢特点。 &2、 说明下列问题：（1）脂肪组织缺乏己糖激酶；（2）肝脏缺乏葡萄糖-6-磷酶酶；（3）肌肉组织中缺乏酰基转移酶。 &3、 双链DNA变性后，为何紫外吸收增加。 &4、 生长膜为双分子层，说明Pro嵌入其中的机理。 &5、 乳糖操纵子为正调控，说明其机理。 &6、 AA分类，各举一例说明。 &7、 能否由多肽AA顺序推导出mRNA碱基顺序，说明其理由。 &8、 何谓wobble 假说。 &9、 说明抗体多样性的分子基础。 &10、 说明反刍动物糖原异生的重要性。
中国农业大学1998年博士研究生入学考试试题（生物化学） &1、 蛋白质二级结构定义并举例说明。 &2、 AA滴定曲线的定义与含义。 &3、 Km值计算方法。 &4、 反刍动物能量来源。 &5、 原核、真核生物基因表达区别。 &6、 tRNA反密码定义；Wobble Hyothesis内容。 &7、 概念：肽键、多肽、操纵子、DNA半保留复制、核小体、过瘤胃蛋白。
中国农业大学1997年博士研究生入学考试试题（生物化学） &1、 反刍动物的蛋白质代谢。 &2、 蛋白质的一级结构及其在结构层次中的作用。 &3、 酮体的生成？它与糖代谢的关系。 &4、 羊毛衫热水洗涤后容易皱缩，而蚕丝蛋白则没有这种现象，为什么？ &5、 真核生物与原核生物DNA复制的不同之处？DNA复制具备什么条件？ &6、 当溶液的PH为丙氨酸等电点时，它以什么形式存在？ &7、 操纵子与操纵基因的概念？它们在基因表达中的作用？ &8、 核糖体的功能？真核与原核生物核糖体的不同？ &9、 氨基酸层析的分离依据于氨基酸的那些特性？离子交换层析中选择洗脱液应该那些因素。
跟帖可以获得流量么？
2006年中国农大博士入学试题生物化学&一、名次解释（40分，每小题4分）&&&&&变构酶、蛋白质结构域、蛋白质靶向定位、复制体模型、核酶、启动子、snRNA、&SDS－PAGE、Antipoter、EST &二、问答题（60分，每小题15分）&1、真核生物与原核生物转录过程有那些差异？简述真核生物转录的主要调控环节。&2、为何说代谢调控实质上是酶活性的调控？酶水平的调控主要指那些层次上的调控，请举例说明。&3、分别举例说明酶蛋白参与物质运输、能量转换、和信号转导三种重要生命活动过程。&4、将组成型启动子控制下的GUS基因，稳定导入到某一生物体，在部分转化子中检测不到GUS活性，在另一部分转化子中虽然检测到GUS活性，但其强弱有明显差异。请予以说明。&2002年生化考题（包括名词解释、填空和简答） &1、单克隆抗体与多克隆抗体的定义、区别，是谁提出的？内容？ &2、与谷氨酸代谢有关的所有途径 &3、生糖氨基酸和生酮氨基酸生成糖的途径 &4.免疫球蛋白的种类 &5.半抗原、抗原决定簇的定义 &6.动物初乳中的免疫球蛋白 &7.酪氨酸的代谢方式和途径 &8.饥饿时三大营养物质的代谢方式、特点 &等等
中国农业大学2000年博士研究生入学考试试题（生物化学）&1概念：Km、过瘤胃蛋白、遗传密码。 &2、 反刍动物蛋白质代谢。 &3、 为什么说复制比转录更精细？ &4、 血液中氨的浓度过高，动物会中毒，为什么喂牛尿素，牛不会中毒，且能正常生长？
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