青岛科技大学826机械设计2012年考研真题
862计算机网络 青岛科技大学-2012年硕士研究生入学考试试题答案
不归零码(NRZ,Not Return to Zero)数字信号可以直接采用基带传输,所谓基带就是指基本频带。
基带传输就是在线路中直接传送数字信号的电脉冲,这是一种最简单的传输方式,近距离通信的局域网都采用基带传输。
基带传输时,需要解决数字数据的数字信号表示以及收发两端之间的信号同步问题。
对于传输数字信号来说,最简单最常用的方法是用不同的电压电平来表示两个二进制数字,也即数字信号由矩形脉冲组成。
按数字编码方式，可以划分为单极性码和双极性码，单极性码使用正（或负）的电压表示数据；双极性码是二进制码，1为反转，0为保持零电平。
根据信号是否归零，还可以划分为归零码和非归零码，归零码码元中间的信号回归到0电平，而非归零码遇1电平翻转，零时不变。
常见的几种基本的数字信号脉冲编码方案如下：单极性不归零码,无电压(也就是无电流)用来表示"0",而恒定的正电压用来表示"1"。
每一个码元时间的中间点是采样时间,判决门限为半幅度电平(即0.5)。
也就是说接收信号的值在0.5与1.0之间,就判为"1"码,如果在0与0.5之间就判为"0"码。
每秒钟发送的二进制码元数称为"码速"。
双极性不归零码,"1"码和"0"码都有电流,但是"1"码是正电流,"0"码是负电流,正和负的幅度相等,故称为双极性码。
此时的判决门限为零电平,接收端使用零判决器或正负判决器,接收信号的值若在零电平以上为正,判为"1"码;若在零电平以下为负,判为"0"码。
以上两种编码,都是在一个码元的全部时间内发出或不发出电流(单极性),以及发出正电流或负电流(双极性)。
每一位编码占用了全部码元的宽度,故这两种编码都属于全宽码,也称作不归零码NRZ (Non Return Zero)。
青岛科技大学2012年研究生入学考试西方经济学试卷
（1）市场均衡价格、均衡交易量； （2）均衡时的消费者剩余与生产者剩余； （3）均衡时的需求价格弹性系数与供给价格弹性系数； （4）政府对每单位产品课征4元的产品税，请问政府税收总和为 多少？生产者与消费者的税收负担各为多少？ 2. 假设有两个寡头垄断厂商的行为遵循古诺模型，他们的成本函数分 别为：
附：近几年存款准备金率波动情况
金融机构 生效日期 大型 小型 生效日期 金融机构 大型 小型
华慧考博—考博第一品牌
华慧网 考博咨询QQ：400 622 4468
第7页共8页
调整后 2011年12月05日 2011年6月20日 2011月5月18日 2011年04月21日 2011年03月25日 2011年02月24日 2011年01月20日 2010年12月20日 2010年11月29日 2010年11月16日 2010年05月10日 2010年02月25日 2010年01月18日 2008年12月25日 2008年12月05日 2008年10月15日 21.00% 21.50% 21.00% 20.50% 20.00% 19.50% 19.00% 18.50% 18.00% 17.50% 17.00% 16.50% 16.00% 15.50% 16.00% 17.00%
D.4.0 % ）
hr，货币供给增加10亿美元，其他条件不变，则会使LM：
A．右移10亿美元； C．右移10亿美元除以k； 三、解释（每小题4分，共计2尼系数 ４．GNP B．右移k乘以10亿美元； D．右移k除以10亿美元；
四、简答（每小题10分，共20分） 1、简述垄断市场形成的条件和原因。 2、凯恩斯分析有效需求不足的三大基本心理规律是什么？ 五、计算（每小题10分，共30分） 1. 已知某家电市场的市场需求和供给分别为： Qs 12 P ；
青岛科技大学2011-2018机械设计考研真题
青岛科技大学二○一一年硕士研究生入学考试试题考试科目：机械设计注意事项：1．本试卷共5道大题（共计37个小题），满分150分；2．本卷属试题卷，答题另有答题卷，答案一律写在答题卷上，写在该试题卷上或草纸上均无效。
要注意试卷清洁，不要在试卷上涂划；3．必须用蓝、黑钢笔或签字笔答题，其它均无效。
﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡一、是非题：正确的以“T”表示，错误的以“F”表示(每小题3分，共30分)1．螺旋传动中的螺母、滑动轴承中的轴瓦、蜗杆传动中的蜗轮，多采用青铜材料，这主要是为了提高导热能力。
2．齿轮外啮合传动中，将渐开线圆柱齿轮齿面间的凸--凸接触，改为凸--凹接触（如双圆弧齿轮）,有利于提高其表面接触强度。
3．螺纹的大径，在标准中定为公称直径。
4．V带剖面中两工作面的夹角为40°，所以V带轮轮槽的工作面的夹角也是40°。
5．与滚子链相比，齿形链有传动平稳、噪声小，效率高，承受冲击载荷能力较好和轮齿受力较均匀的优点。
6．直齿圆锥齿轮强度计算中，是以大端当量直齿圆柱齿轮为计算依据的。
7．蜗杆传动的传动比等于蜗轮、蜗杆的直径比。
8．滑动轴承材料中，多孔质粉末冶金材料有自润滑性能。
9．自行车前轴属于固定心轴。
10．联轴器与离合器的主要作用是缓和冲击和振动。
二、选择填空(每小题3分，共30分)1．在机械传动中，理论上能保证瞬时传动比为常数的是。
Ａ.带传动Ｂ.链传动Ｃ.摩擦轮传动Ｄ.齿轮传动2．运动粘度v是动力粘度η与同温下润滑油的比值。
Ａ．密度ρＢ．质量mＣ．压力pＤ．速度u3．当两个被联接件都比较薄，在被联接件上宜制成通孔，通孔的加工精度要求低，结构简单，装拆方便，往往采用。
A．双头螺柱联接B．绞制孔用螺栓联接C．普通螺栓联接D．螺钉联接4．键的截面尺寸（键宽×键高）主要根据来选择。
Ａ．轴的直径Ｂ．传递功率的大小Ｃ．轮毂的长度Ｄ．传递转矩的大小5．带传动的主要失效形式之一是带的。
2012年青岛科技大学862计算机网络考研真题硕士研究生专业课考试试题
青岛科技大学二○一二年硕士研究生入学考试试题考试科目：计算机网络注意事项：1．本试卷共 3 道大题（共计39 个小题），满分150 分；2．本卷属试题卷，答题另有答题卷，答案一律写在答题卷上，写在该试题卷上或草纸上均无效。
要注意试卷清洁，不要在试卷上涂划；3．必须用蓝、黑钢笔或签字笔答题，其它均无效。
﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡一、单项选择题（每小题2分，共50分）1．UDP协议是________的传输层协议。
A、无连接的、可靠的B、面向连接的、可靠的C、面向连接的、不可靠的D、无连接的、不可靠的2．私网地址用于配置公司内部网络，下面选项中，________属于私网地址。
A、171.168.10.1B、11.15.0.1C、127.10.0.1D、192.168.0.13．在OSI模型中，第N层和其上的第N+1层的关系是________。
A、第N层为第N+1层服务B、第N+1层将从第N层接收的信息增加了一个头部C、第N层利用第N+1层提供的服务D、第N层对第N+1层没有任何作用4．对应于OSI/RM模型中的数据链路层，在IEEE 802局域网标准中，可以细分为________两层。
A、LLC、VTB、MAC、FTAM C、MAC、LLCD、LLC、FTAM 5．IP数据报穿越Internet过程中有可能被分片，在数据报被分片后，________负责IP数据报的重组。
A、源主机B、目的主机C、分片途经的路由器D、分片途经的路由器和目的主机6．在网络179.62.2.0/23中,以下哪个IP地址可以被分配给该网络的主机?A. 179.62.2.0B. 179.62.2.255C. 179.62.3.255D. 179.62.4.0 7．IP数据报从源节点到目的节点可能要经过多个网络，在传输过程中IP数据报头部中的________。
A、源IP地址和目的IP地址都不会发生变化；B、源IP地址不会发生变化，目的IP地址会发生变化；第页（共61C、源IP地址会发生变化，目的IP地址不会发生变化；D、源IP地址和目的IP地址都会发生变化；8．当PCM用于数字化语音系统时，如果将声音分为256个量化级，由于系统的采样速率为8000样本/秒，那么数据传输速率应该达到________。
【青岛大学2012年考研专业课真题】机械控制工程基础2012
ma x ，并计算当相位裕量为最大值 max 时，系统的开环截止频率 c 和增益
Kc 。 （20 分)
2
R( s )
K c (1 Βιβλιοθήκη 1 ) sKs 1 Ta s
1 Ti s
C ( s)
七．设系统的开环传递函数为 GK ( s)
K (T2 s 1) (其中K 0, T1 0, T2 0) s 2 (T1 s 1)
试画出 Nyquist 图， 并确定系统的稳定性。 （要求： 按 T1 T2 ，T1 T2 ，
T1 T2 三种情况分别讨论） 。 （30 分）
八．一单位反馈系统的开环传递函数为
G( s)
K s(1 0.2s)(1 0.05s)
求： （1） K 1 时系统的相位裕度和幅值增益裕度。 （10 分） （2）要求通过增益 K 的调整，使系统的增益裕度为 20dB，相位裕度 满足 40 。 （10 分）
青岛大学 2012 年硕士研究生入学考试试题
科目代码： 821 科目名称： 机械工程控制基础 （共 3 页） 请考生写明题号，将答案全部写在答题纸上，答在试卷上无效 注：仅限使用只具有计算功能的计算器 一．仓库大门自动控制系统如图所示，试分析系统的工作原理，绘制系统 的方框图。 （10 分）
放大器
伺服电动机
1
四. 如图所示的单位反馈随动系统， K 16s 1 ,T 0.25s ，试求：
（1）求特征参数 ， n ； （5 分） （2）计算最大超调量和调整时间； （ 2% ） （5 分） （3）若要求最大超调量为 16%，当 T 不变时 K 应当取何值？（10 分）
五.系统的结构图如图所示，试求
2012年青岛科技大学861数据结构考研真题研究生入学考试试卷
9、若一棵二叉树具有10个度为2的结点，则该二叉树的度为0的结点个数是。
A、9B、11C、12D、不确定
10、高度为h的二叉树（仅含根结点的二叉树高度为零）的结点最少是多少。
A、2h＋1B、h＋1C、2h+1－1D、2h
11、由权值分别为3,8,6,2,5的叶子结点生成一棵哈夫曼树，它的带权路径长度为。
a[i][j]=i*j;
A、O(m*n)B、 O(n2)C、O(m2)D、 O(m+n)
3、在一个长度为n的顺序存储线性表中，向第i个元素(1≤i≤n+1)之前插入一个新元素时，需要从后向前依次后移个元素。
A、n-iB、n-i+1C、n-i-1D、i
4、在一个长度为n的线性表中顺序查找值为x的元素时，查找时的平均查找长度（即x同元素的平均比较次数，假定查找每个元素的概率都相等）为。
青岛科技大学
二○一二年硕士研究生入学考试试题
考试科目：数据结构
注意事项：1．本试卷共四道大题（共计38个小题），满分150分；
2．本卷属试题卷，答题另有答题卷，答案一律写在答题卷上，写在该试题卷上或草纸上均无效。要注意试卷清洁，不要在试卷上涂划；
3．必须用蓝、黑钢笔或签字笔答题，其它均无效。
﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡
A、72B、53C、48D、24
12、ALV树是一种平衡的二叉排序树，树中任一结点的()。
A、左、右子树高度差的绝对值不超过1B、左、右子树的高度均相同
C、左子树的高度均大于右子树的高度D、左子树的高度均小于右子树的高度
13、下列线性结构中能用折半法进行查找的是。
A、单链表B、顺序存储的有序线性表 C、二叉链表 D、有序线性链表
青岛科技大学826机械设计2007-2012、2016-2017年考研专业课真题试卷
青岛科技大学二○一七年硕士研究生入学考试试题考试科目：机械设计注意事项：1．本试卷共四道大题（共计28个小题），满分150分；2．本卷属试题卷，答题另有答题卷，答案一律写在答题卷上，写在该试题卷上或草纸上均无效。
要注意试卷清洁，不要在试卷上涂划；3．必须用蓝、黑钢笔或签字笔答题，其它均无效。
﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡一、选择题(每小题3分，共30分)1．温度升高时，润滑油的粘度。
A. 随之升高B. 保持不变C．随之降低 D. 可能升高也可能降低2．在螺纹联接中，按防松原理，采用对顶螺母属于________。
A. 摩擦防松B. 机械防松C. 破坏螺旋副的关系防松D. 增大接触面积防松3．当键联接强度不足时可采用双键联接。
使用两个平键时，要求键布置。
A. 在同—直线上B. 相隔900C. 相隔1200D. 相隔18004. 带传动在工作时产生弹性滑动，是由于。
A. 包角α太小B. 初拉力F0太小C. 紧边与松边拉力不等D. 传动过载5. 用普通螺栓联接的凸缘联轴器，在传递转矩T 时，________。
A. 螺栓受剪切B．螺栓与孔壁接触面受挤压C. 螺栓同时受剪切与挤压D．螺栓受拉伸与扭转6. 带传动采用张紧装置的目的是_________。
A. 减轻带的弹性滑动B. 提高带的寿命C. 改变带的运动方向D. 调节带的初拉力7．在润滑良好的条件下，为提高蜗杆传动的啮合效率，可采用的方法为________。
A. 选择有自锁功能的蜗杆B. 减少蜗杆头数Z1C. 增加蜗杆头数Z1D. 增大蜗杆直径系数q第页（共4页）1。
青岛科技大学2012年研究生入学考试英语试卷
青岛科技大学二○一二年硕士研究生入学考试试题考试科目：英语注意事项：1．本试卷共6道大题（共计 47 个小题），满分100 分；2．本卷属试题卷，答题另有答题卷，答案一律写在答题卷上，写在该试题卷上或草纸上均无效。
要注意试卷清洁，不要在试卷上涂划；3．必须用蓝、黑钢笔或签字笔答题，其它均无效。
﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡PART I. READING COMPREHENSION (38%)Directions: Read the passages given below and choose the best answer to the questions attached to each of them.Passage OneQuestions 1-3 are based on the following passage.If you like the idea of staying with a family, living in house might be the answer. Good landladies---those who are superb cooks and launders, are figures as popular in fiction as the bad ones who terrorize their guest and overcharge them at the slightest opportunity. The truth is probably somewhere between the two extremes. If you are lucky, the food will be adequate, some of your laundry may be done for you and you will have a reasonable amount of comfort and companionship .For the less fortune,house rules may restrict the freedom to invite friends to visit, and shared cooking and bathroom facilities can be frustrating and row-provoking if tidy and untidy guest are living under the same roof.The same disadvantages can apply to flat sharing, with the added difficulties that arise from deciding who pays for what, and in what proportion. One person may spend hours on the phone, while another rarely makes calls. If you want privacy with guest, how do you persuade the others to go out; how do you persuade them to leave you in peace, especially if you are student and want to study?Conversely, flat sharing can be very cheap, there will always besomeone to talk to and go out with, and the chores ,in theory, can beshared.1.According to the passage ,landladies are ________ ually strict. B. always mean. C. adequately competent. D. very popular with their guest.2.What is the additional disadvantage of flat sharing ? A. Problems of sharing and paying. B. Differences in living habits. C. Shared cooking and bathroom facilities. D. Restriction to invite friends to visit.3.What is NOT mentioned as a benefit of flat sharing? A. Rent is affordable B. There is companionship. C. Housework.D. There is peace and quiet.Passage TwoQuestions 4-8 are based on the following passage. I am afraid to sleep. I have been afraid to sleep for the last few weeks.I am so tired that, finally, I do sleep, but only for a few minutes. It is not abad dream that wakes me; it is the reality I took with me into sleep . I tryto think of something else. Immediately the woman in the marketplace comes into my mind. I was on my way to dinner last night when I saw her . She was sellingskirts. She moved with the same ease and loveliness I often saw in thewomen of Laos. Her long black hair was as shiny as the black silk of theskirts she was selling. In her hair, she wore three silk ribbons, blue, green,and white. They reminded me of my childhood and how my girlfriendsand I used to spend hours braiding ribbons into our hair. I don’t know the word for “ribbons”, so I put my hand to my own hairand , with three fingers against my head , I looked at her ribbons and said “Beautiful.” She lowered her eyes and said nothing. I wasn’t sure if sheunderstood me (I don’t speak Laotian very well). I looked back down at the skirts. They add designs in them: squaresand triangles and circles of pink and green silk. They were very pretty. Idecided to buy one of those skirts, and I began to bargain with her overthe price. It is the custom to bargain in Asia. In Laos bargaining is done in soft voices and easy moves with the sort of quiet peacefulness. She smiled, more with her eyes than with her lips. She was pleased by the few words I was able to say in her language, although they were mostly numbers, and she saw that I understood something about the soft playfulness of bargaining. We shook our heads in disagreement over the price; then, immediately, we made another offer and then another shake of the head. She was so pleased that unexpectedly, she accepted the last offer I made. But it was too soon. The price was too low. She was being too generous and wouldn’t make enough money. I moved quickly and picked up two more skirts and paid for all three at the price set; that way I was able to pay her three times as much before she had a chance to lower the price for the larger purchase. She smiled openly then, and, for the first time in months, my spirit lifted. I almost felt happy. The feeling stayed with me while she wrapped the skirts in a newspaper and handed them to me. When I left, though, the feeling left, too. It was as though it stayed behind in marketplace. I left tears in my throat. I wanted to cry. I didn’t , of course. I have learned to defend myself against what is hard; without knowing it, I have also learned to defend myself against what is soft and what should be easy. I get up, light a candle and want to look at the skirts. They are still in the newspaper that the woman wrapped them in. I remove the paper, and raise the skirts up to look at them again before I pack them. Something falls to floor. I reach down and feel something cool in my hand. I move close to the candlelight to see what I have. There are five long silk ribbons in my hand, all different colors. The woman in the marketplace! She has given these ribbons to me! There is no defense against a generous spirit, and this time I cry, and very hard, as if I could make up for all the months that I didn’t cry.4. Which of the following in NOT correct?A. The writer was not used to bargaining.B. People in Asia always bargain when buying things.C. Bargaining in Laos was quiet and peaceful.D. The writer was ready to bargain with the woman.5. The writer assumed that the woman accepted the last offer mainly because womanA. thought that the last offer was reasonable.B. thought she could still make much money.C. was glad that the writer knew their way of bargaining.D. was tired of bargaining with the writer any more.6. Why did the writer finally decide to buy three skirts?A. The skirts were cheap and pretty.B. She liked the patterns on the skirts.C. She wanted to do something as compensation.D. She was fed up with further bargaining with the woman.7. When did the writer left the marketplace, she wanted to cry, but did not becauseA. she had learned to stay cool and unfeeling.B. she was afraid of crying in public.C. she had learned to face difficulties bravely.D. she had to show in public that she was strong.8. Why did the writer cry eventually when she looked at the skirts again?A. she suddenly felt very sad.B. she liked the ribbons so much.C. she was overcome by emotion.D. she felt sorry for the woman.Passage ThreeQuestions 9-14 are based on the following passage.The kids are hanging out. I pass small bands of students, in my way to work these morings. They have become a familiar part of the summer landscape.These kids are not old enough for jobs. Nor are they rich enough for camp. They are school children without school. The calendar called the school year ran out on them a few weeks ago. Once supervised by teachers and principals, they now appear to be “self care”.Passing them is like passing through a time zone. For much of our history, after all, Americans arranged the school year around the needs of work and family. In 19th-century cities, schools were open seven or eight hours a day, 11 months a year. In rural America, the year was arranged around the growing season. Now, only 3 percent of families follow the agricultural model, but nearly all schools are scheduled as if our children went home early to milk the cows and took months off to work the crops. Now, three-quarters of the mothers of school-age children work, but the calendar is written as if they were home waiting for the school bus.The six-hour day, the 180-day school year is regarded as something holy. But when parents work an eight-hour day and a 240-day year, it means something different. It means that many kids go home to empty houses. It means that, in the summer, they hang out. “We have a huge mismatch between the school calendar and realities of family life,” says Dr. Ernest Boyer, head of the Carnegie Foundation for the Advancement of Teaching.Dr. Boyer is one of many who believe that a radical revision of the school calendar is inevitable.＂School, whether we like it or not, iseducational. It always has been.”His is not popular idea. School are routinely burdened with the job of solving all our social problems. Can they be asked to meet the needs of our work and family lives?It may be easier to promote a linger school year on its educational merits and, indeed, the educational case is compelling. Despite the complaints and studies about our kids’ lack of learning, the United State still has a shorter school year than any industrial nation. In most of Europe, the school year is 220 days. In Japan, it is 240 days long. While classroom time alone doesn’t produce a well-educated child, learning takes time and more learning takes more time. The long summers of forgetting take a toll.The opposition to a longer school year comes from families that want to and can provide other experiences for their children. It comes from teachers. It comes from tradition. And surely from kids. But the most important part of the conflict has been over the money.9. Which of the following is an opinion of the author’s?A.＂The kids are hanging out.”B.＂They are school children without school.”C.＂These kids are not old enough for jobs.”D. “The calendar called the school year ran out on them a few weeks ago.”10. The current American school calendar was developed in the 19th century according toA. the growing season on nation’s form.B. the labor demands of the industrial age.C. teachers’ demands for more vacation time.D. parents’ demands for other experiences for their kids.11. The author thinks that the current school calendarA. is still valid.B. is out of date.C. can not be revised.D. can not be defended.12. Why was Dr. Boy’s idea unpopular?A. He argues for the role of school in solving social problems.B. He supports the current school calendar.C. He thinks that school year and family life should be considered separately.D. He strongly believes in the educational role of school.13. “The long summers of forgetting take a toll ”in the last paragraph but one means thatA. long summer vacation slows down the progress go learning.B. long summer vacation has been abandoned in Europe.C. long summers result in less learning time.D. long summers are a result of tradition.14. The main purpose of the passage isA. to describe how American children spend their summer.B. to explain the needs of the modern working families.C. to discuss the problems of the current school calendar.D. to persuade parents to stay at home to look after their kids. Passage FourQuestions 15-19 are based on the following passage.Women's minds work differently from men's. At least, that is what most men are convinced of. Psychologists view the subject either as a matter of frustration or a joke. Now the biologists have moved into this minefield, and some of them have found that there are real differences between the brains of men and women. But being different, they point out hurriedly, is not the same as being better or worse.There is, however, a definite structural variation between the male and female brain. The difference is in a part of the brain that is used in the most complex inte11ectual processes-the link between the two halves of the brain.The two halves are linked by trunkline of between 200 and 300 million nerves, the Corpus callosum. Scientists have found quite recently that the Corpus callosum in women is always larger and probably richer in nerve fibers than it is in men. This is the first time that a structural difference has been found between the brains of women and men and it must have some significance. The question is "What?", and, if this difference exists, are there others? Research shows that present-day women think differently and behave differently from men. Are some of these differences biological and inborn, a result of evolution? We tend to think that is the influence of society that produces these differences. But could we be wrong?Research showed that these two halves of the brain had different functions, and that the Corpus callosum enabled them to work together. For most people, the left half is used for word - handling, analytical and logical activities; the right half works on pictures, patterns and forms. We need both halves working together. And the better the connections, the more harmoniously the two halves work. And, according to research findings, women have the better connections.But it isn't all that easy to explain the actual differences between skills of men and women on this basis. In schools throughout the world girls tend to be better than boys at“language subjects”and boys better at maths and physics. If these differences correspond with the differences in the hemispheric trunkline, there is an unalterable distinction between the sexes.We shan't know for a while, partly because we don't know of any precise relationship between abilities in school subjects and the functioning of the two halves of the brain ,and we cannot understand how the two halves interact via the corpus callosum. But this striking difference must have some effect and, because the difference is in the parts of the brain involved in intellect, we should be looking for differences in intellectual processing.15. Which of the fo11owing statements is CORRECT?A. Biologists are conducting research where psychologists have given up.B. Brain differences point to superiority of one sex over the other.C. Results of scientific research fail to support popular belief.D. The structural difference in the brain between the sexes has long been known.16. According to the passage it is commonly believed that brain differences are caused by ________ factors.A. biologicalB .psychologicalC. physicalD .social17."these differences" in paragraph 5 refer to those inA. skills of men and women.B. school subjects.C. the brain structure of men and women.D. activities carried out by the brain.18. At the end of the passage the author proposes more work onA. the brain structure as a whole.B. the functioning of part of the brain.C. the distinction between the sexes.D. the effects of the corpus callosum.19. What is the main purpose of the passage?A. To outline the research findings on the brain structure.B. To explain the link between sex and brain structure.C. To discuss the various factors that cause brain differences.D. To suggest new areas in brain research.PART II CLOZE (15%)Directions: Choose a proper word from the list to fill in each blank in the following passage. Change the form of the word if necessary. base create evoke suffice handdeeply poorly dispose degree dependvary religious present movement endeavorEverything that the human race has done and thought is concerned with the satisfaction of (1)__________ felt needs and the assuagement of pain. One has to deep this constantly in mind if one wishes to understand spiritual (2)___________ and their development. Feeling and longing are the motive force behind all human (3)___________ and human creation, in however exalted a guise the latter may (4)__________ themselves to us. Now what are the feelings and needs that have led men to(5)__________ thought and belief in the widest sense of the words? A little consideration will (6)___________ to show us that the most(7)___________ emotions preside over the birth of religious thought and experience. With primitive man it is above all fear that (8)__________ religious notions—fear of hunger, wild beasts, sickness, death. Since at this stage of existence understanding of causal connections is usually (9)__________ developed, the human mind (10)__________ illusory beings more or less analogous to itself on whose wills and actions these fearful happenings (11)___________. Thus one tries to secure the favor of these beings by carrying out actions and offering sacrifices which, according to the tradition (12)_________ down from generation to generation, propitiate them or make them well (13)___________ toward a mortal. In this sense I am speaking of a religion of fear. This, though not created, is in an important (14)___________ stabilized by the formation of a special priestly caste which sets itself up as a mediator the people and the beings they fear, and erects a hegemony on this (15)________. PART III TRANSLATION (15%)（I）．Translate the following into Chinese:（10%）1. This discovery suggests that life is probably a pretty ordinary phenomenon that occurs any place you give it half a chance.2. But I find it helpful to consider what might have happened in my own marriage if a copy of me had been made to overcome infertility.3. Forty years after the Wright Brothers’ first flight, by contrast, commercial air travel was a dauntingly expensive but widespread and growing industry.4. The promissory notes of well-known individuals and bills of exchangedrawn on English merchants readily exchanged hands for severalmonths.5．When the demand becomes immoderate, consumption of drugs increases and the incidence of adverse effects and waste follows suit.（II）． Translate the following into English （5%）随着1997年许多东亚国家经济中出现的戏剧性的货币贬值，这些国家遭受了急剧而且徘徊不去的经济衰退。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
图5
C）静应力D）对称循环变应力
二、填空题（1小分）在齿轮传动的设计和计算中，对于下列参数和尺寸应标准化的有；应圆整的有；没有标准化的也不应圆整的有。
（1）斜齿圆柱齿轮的法面模数 （2）斜齿圆柱齿轮的端面模数
(3)分度圆直径 （4）齿顶圆直径 (5)齿轮宽度B
5.简述轴的设计步骤。
四、分析、计算题（共40分）
1.（15分）已知普通螺栓连接的预紧力 N，螺栓刚度 kN/mm，被连接件刚度 kN/mm，试在图中作出螺栓连接的受力变形线图（以横坐标代表变形、纵坐标代表力）；若螺栓连接在轴向外载荷 的作用下，伸长了 mm，试在图中准确的标出螺栓总拉力 ，外载荷 ，残余预紧力 。
A）制造困难B）要使用较长的销轴
C）不便于装配D）链板要产生附加的弯曲应力
6.如图3所示齿轮传动，轮1为主动轮，则轮2的齿面接触应力按变化。
A）对称循环B）脉动循环C）循环特性 D）循环特性
图3
7.巴氏合金通常用于作滑动轴承的。
A）轴套B）轴承衬C）含油轴瓦D）轴承座
8.两相对滑动的接触表面，依靠吸附油膜进行润滑的摩擦状态称。
2.V型带传动在工作过程中可能出现打滑现象，有人说这就是影响V带传动效率的主要原因，你同意这一观点吗？请说明理由。
3．齿轮传动中的载荷系数 为四个系数的乘积， ，分别说明 和 的名称及引入该系数是为了考虑哪些方面的影响？齿顶修缘、轮齿的螺旋角修形（鼓形齿）目的各是什么？
4．试分析比较滚动轴承、液体润滑滑动轴承、不完全液体润滑滑动轴承的特点及应用（提示：从摩擦系数的大小、工作转速的高低、是否可用于频繁启动的场合、承受冲击载荷的能力、回转精度等方面进行论述）。
（6）分度圆压力角 （7）斜齿轮螺旋角 (8)变位系数
（9）中心距a（10）齿厚s
2.下列各种联轴器中，能减缓振动和冲击的是；可实现两轴线角位移最大的是；常用于两轴线对中性不好、低速情况下的是和。
（1）凸缘联轴器（2）万向联轴器（3）齿轮联轴器（4）弹性柱销联轴器
3.在疲劳曲线上，以循环基数N0为界分为两个区：当N≥N0时，为区；当N＜N0时，为区。
A）液体摩擦B）半液体摩擦C）边界摩擦D）混合摩擦
9.设计滚动轴承合理的配置时，对轴承跨距较小且工作温度较低的轴，应考虑。
A）双支点各单向固定B）一支点双向固定，另一端支点游动
C）两端游动支承D）轴颈与轴承内圈采用很松的配合
10.若转动心轴工作时，外载大小、方向均不变，则轴的弯曲应力的性质是。
A）非对称循环变应力B）脉动循环变应力
4.普通螺纹连接的公称直径指的是螺纹的，计算螺纹危险截面时使用的是螺纹的。
5.对于普通平键，考虑到载荷分布的不均匀性，双键连接的强度按个键计算。
6.直齿圆锥齿轮传动强度计算方法是以的当量圆柱齿轮为计算的依据。
三、简答题（每小题10分,共50分）
1.螺纹连接的基本类型主要有哪四种，并说出其各自应用场合。
A）1，2 B）1，3 C）2，4 D）2，3
图1
3．螺旋传动常用梯形螺纹，其主要原因是。
A）提高自锁性B）制造方便
C）螺纹强度、效率均较高D）A、B、C均不对
4.图2中V型带在轮槽中安装情况，正确的是________。
A）B) C）D）
图2
5．滚子链传动中，链节数应尽量避免采用奇数，这主要是因为采用过渡链节后________。
2.（15分）在图4所示电动绞车系统中，件1和2均为斜齿圆柱齿轮，件3为蜗杆，件4
为蜗轮。已知蜗轮为右旋，并且设计时希望使Ⅱ轴上齿轮2与蜗杆3的轴向力能够相互抵消一部分，试回答下列问题：
图4
（1）齿轮1、2及蜗杆3的轮齿螺旋线方向各是什么旋向；（2分）
（2）在图中用箭头表示出重物上升时齿轮1和齿轮2的转动方向以及齿轮2在节点A所受的轴向力 的方向；（4分）
一、选择题(每小题3分，共30分)
1．在右图所示的 - 极限应力简图中，如工作应力点M所在的 线与横轴间夹角 ，则该零件受的是________。
A）不变号的非对称循环变应力
B）脉动循环变应力
C）对称循环变应力D）静应力
2.图1中板A用4个铰制孔用螺栓固定在板B上，受力为F，其中_____两个螺栓受力最大。
青岛科技大学
二○一二年硕士研究生入学考试试题
考试科目：机械设计
注意事项：1．本试卷共四道大题（共计24个小题），满分150分；
2．本卷属试题卷，答题另有答题卷，答案一律写在答题卷上，写在该试题卷上或草纸上均无效。要注意试卷清洁，不要在试卷上涂划；
3．必须用蓝、黑钢笔或签字笔答题，其它均无效。
﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡﹡
（3）重物上升时，在节点B处画出蜗杆3所受的三个分力的方向以及蜗轮4所受的圆周力 的方向；（4分）
（4）若起重量W=50000N，蜗杆头数z3=2，蜗杆分度圆直径d3=100mm，蜗轮齿数z4=60，模数m=5，卷筒直径D=300mm，传动效率η=0.8。求节点B处Fa3和Fa4的大小。（5分）
3．（10分）如图5所示，一蜗杆轴由一对角接触球轴承70308AC支承。载荷系数 =1.2。求两轴承的当量动载荷 和 ,并分析指出哪个轴承的寿命较长，为什么。