ch04
市场营销重点课程Ch04 消费者市场和购买行为分析
第四章第一部分消费者市场和购买行为分析（一）单项选择题（在下列每小题中，选择一个最合适的答案。
）1、_________是人类欲望行为最基本的决定因素。
A．文化B．性格C．国家D．社会2、消费者的购买单位是个人或_________。
A．集体B．家庭C．社会D．单位3、大多数消费者只能根据个人好恶和做出购买决策。
A．智慧B．经验C．感觉D．能力4、某种相关群体的有影响力的人物称为。
A．“意见领袖”B．“道德领袖”C．“精神领袖”D．“经济领导者”5、一个人的_________影响着消费需求和对市场营销因素的反应。
A．能力B．个性C．联系D．精神6、不同生活方式_________对产品和品牌有不同的需求。
A．群体B．社会C．模型D．艺术7、马斯洛认为需要按其重要程度分，最低层次需要是指_________。
A．生理需要B．社会需要C．尊敬需要D．安全需要8、_________在人格诸领域中最后形成，反映社会的各项准则，由理想、道德、良心等组成。
A．本我B．超我C．自我D．含我9、_________指存在于人体内驱使人们产生行为的内在刺激力，即内在需要。
A．刺激物B．诱因C．反应D．驱使力10、消费者购买过程是消费者购买动机转化为_________的过程。
A．购买心理B．购买意志C．购买行动D．购买意向11、体育明星和电影明星是其崇拜者的。
A．成员群体B．直接参照群体12、下列哪个因素不是影响消费者购买行为的主要因素_________。
A．文化因素B．社会因素C．自然因素D．个人因素13、对于减少失调感的购买行为，营销者要提供完善的_________，通过各种途径提供有利于本企业和产品的信息，使顾客确信自己购买决定的正确性。
A．售前服务B．售后服务C．售中服务D．无偿服务14、在复杂的购买行为中，消费者购买决策过程的第三个阶段是。
A．确认B．收集信息C．备选产品评估D．决定购买15、消费者对于有些产品品牌差异明显，但消费者不愿花长时间来选择和估价，而是不断变换所购产品的品牌，这种购买行为称为_________。
机器人机构学【ch04】串联机器人机构拓扑结构特征与综合 培训教学课件
串联机器人机构拓扑结构特征
4)同一连杆上两运动副轴线相交于 一点，两者共用“⌒”表示。
5)若干个P副平行于同一平面，用 (-P-P-…-P-)表示。
“
6)同一连杆上两运动副轴线垂直，两者之间用“⊥”表示。
i(扭角)：两相邻运动副轴线之间的夹角，即按右手坐标 系，绕xi轴线由zi到zi+1的转角。
串联机器人机构拓扑结构特征
1)两运动副轴线重合，即 αi=0，ai=0。
2)两运动副轴线平行，即 αi=0，ai≠0。
上述机器人连 杆的关节运动 副可特殊配置
如下：
3)两运动副轴线相交于一 点，即αi≠0，ai=0。
”
串联机器人机构拓扑结构特征
串联机器人机构的活动度公式
串联机器人机构的活动度公式为
m
F fi i1
式中，F为机构活动度；m为机构运动副数；fi为第i个运动副自由度数。
串联机器人机构拓扑结构特征
串联机器人机构运动输出特征矩阵
串联机器人机构的位移输出与速度输出
串联机器人机构的位移输出是末端连杆的位置与方向(位姿)，为机构运动输入的函数。串
串联机器人机构运动输出特征方程
4)相互平行(重合)的两个转动必相关， 只对应一个独立转动输出。
5)平行于同一平面的三个转动必 相关。
“ 6)不平行于同一平面的四个转动必相关，三维空间内最多有三个独立的转动输出。 ”
03
串联机器人机构运动 输出特征矩阵运算
串联机器人机构运动输出特征矩阵运算 运动输出特征矩阵运算规则
步骤1 选定单开链的运动 输出特征矩阵MS。
ch04决策支持系统(新)
Is
中国的陆地面积
960万平方公里
Is型语义网络
3 语义网络
基本的语义关系 (2)属性(类属)关系
Have ：表示一个结点具有另一个结点所描述的属性
Have
鸟
翅膀
Have属性关系语义网络
3 语义网络
基本的语义关系 (2)属性(类属)关系
A-Kind-of ：表示一个事物是另一个事物的一 种类型，表示隶属关系。
❖ 按此规则前提的判断得出结论的判断，由此回溯到上一 个规则的推理，一直回溯到目标的判断。
（2）逆向推理
V V
1、A B->G 2、C D->A 3、E->D
产生式规则库
推理过程：
G
A
B
B、C、E
事实库
D
E
C
3 语义网络
由J.R.Quilian于1968年在研究人类联想记忆时提出 的一种心理学模型。 基本思想： ❖ 用结点表示概念，用弧线表示概念之间的关系，将领
弧是有方向和标注的，方向体现了结点所代表的实体的 主次关系，即结点1为主，结点2为辅；
标注表示所连接的两个实体之间的语义联系。
3 语义网络
试用语义网络表示命题“某学校小学生坐车去春 游”。
某学校
属于 小学生 动作目的 春游
动作方式
坐车
3 语义网络
基本的语义关系
(1)Is-a和Part-of型关系 Is-a：表示一个事物是另一个事物的实例，表示 具体与抽象关系，此关系的一个最主要的特点是 属性的继承关系。
系统工程专业本科学员必修课
决策支持系统
第四章 智能决策支持系 统和智能技术的决策支持
本章内容
➢智能决策支持系统概述 ➢人工智能基本原理 ➢专家系统与智能决策支持系统 ➢神经网络的决策支持 ➢遗传算法的决策支持 ➢机器学习的决策支持
Ch04 一阶过程和二阶过程的动态特性
峰值时间 最大超调nput Signals
Ramp function
xi
a
a=1 称为单位斜坡函数
0
1
t
Sinusoidal function
§4-1 Typical Input Signals
究竟采用哪种典型信号？
取决于系统在正常工况下最常见的输入信号形式 斜坡信号 阶跃信号 脉冲信号 正弦信号 随时间逐渐变化的输入 突然的扰动量、突变的输入 冲击输入 随时间往复变化的输入
1 0
5
wnt
10
15
阻尼系数、特征根与二阶系统单位阶跃响应
阻尼系数 特征根
[s]
二阶系统单位阶跃响应
[s]
[s]
阻尼系数、特征根与二阶系统单位阶跃响应
阻尼系数 特征根
[s]
二阶系统单位阶跃响应
[s]
[s]
§5-4 Time-domain Performance Specifications
时域分析性能指标是以系统对单位阶跃输入的瞬态响应 形式给出的。
§4-3 Transient Response of Second-order Systems
二阶系统：
能够用二阶微分方程描述的系统。 它的典型形式是二阶振荡环节。
形式一：
形式二：
二阶系统的单位阶跃响应
单位阶跃输入
则：
根据二阶系统的 极点分布特点， 分五种情况进行 讨论。
欠阻尼 临界阻尼 过阻尼 零阻尼 负阻尼
t
瞬态响应
稳态响应
——动态性能描述
——稳态性能描述
标准过程输入 一阶系统的瞬态响应 二阶系统的瞬态响应
ch04弹性理论
弹性公式
弧弹性公式
ΔQ/（Qa+Qb）/2 ΔQ Pa+Pb Ed = -———————— 或 =- — × —— ΔP/（Pa+Pb）/2 ΔP Qa+Qb
点弹性公式与计算
dQ/Q dQ P Ed =- —— 或 = -—×— dP/P dP Q
弹性计算
某杂志价格为2元时销售量为5万册，价格为3元 时销售量为3万册，则需求价格弹性为多少？
以大幅度减少，税收就主要由生产者承当。
对食盐、香烟、汽油征税和娱乐产业征税的不同效果
练习回复
在竞争性商品X市场中，有10000个相同的个人，每个人的需求函数都是 Qd＝12 －2P，同时又有1000个相同的生产者，每个生产者的供给函数都是Qs＝20P. 1）求商品X的市场需求函数和市场供给函数。 2）在同一坐标系中，绘出商品X 的市场需求曲线和市场供给曲线，并表示出 均衡点。 3）求均衡价格和均衡产销量。
影响需求价格弹性的因素
商品的可替代性 商品用途的广泛性
商品对消费者的重要程度
商品的消费支出在消费总支出中所占的比重
消费者调节需求量的时间。
需求收入弹性
定义：需求收入弹性是指某种商品需求量变动的百 分比与收入变动的百分比之比。
公式：ΔQ/Q
ΔY/Y
ΔQ Y
ΔY Q
Ey = —— 或 = —× —
解：P=1，则Qs = c+d，另dQ/dP= d dQ P 1 d Es = —×— = d × —— = —— dP Q c+d c+d
分类及影响因素
①Es=0，供给完全无弹性 ②0<Es<1，供给缺乏弹性
离散数学CH04_图论_根树
4.6 树
4.6 树
图中的三棵树T1，T2和T3都是带权2，2，3，3，5
的二叉树，它们的权分别是：
W(T1)=2×2＋2×2＋3×3＋5×3＋3×2=38 W(T2)=3×4＋5×4＋3×3＋2×2＋2×1=47 W(T3)=3×3＋3×3＋5×2＋2×2＋2×2=36 以上三棵树都是带权2,2,3,3,5的赋权二叉树，但不 是最优树。
【例】求图所示的二叉树产 生的前缀码。 解：在图(a)中，每一个 分枝点引出的左侧边标记0， 右侧边标记1。由根结点到 树叶的路经上各边的标记组 成的0、1序列作为对应树叶 的标记，如图 (b)所示。产 生的前缀码为： 01,11,000,0010,0011
4.6 树
定理 任意一个前缀码，都对应一个二叉树。 证明：
4.6 树
给定了一个前缀码，设h是其中最长序列的长度。画出一个高为 h的正则二叉树。按定理9.6.7中描述的办法给各边标记0或1。 每一个结点对应一个0、1序列，它是由根结点到该结点的路经 上各边的标记组成的。如果某个0、1序列是前缀码的元素，则 标记该结点。将已标记结点的所有后代和该结点的射出边全部删 除，得到了一个二叉树，再删除未加标记的树叶，就得到要求的 二叉树。
在通信中常用0、1字符串表示英文字母，即用二进制 数表示英文字母。最少用多少位二进制数就能表示26
个英文字母呢？1位二进数可以表示2=21个英文字母
，两位二进制数可以表示4=22个英文字母，……，n 位二进制数可以表示2n个英文字母。如果规定，可以 用1位二进制数表示英文字母，也可以用两位二进制数 表示英文字母。
4.6 树
定理 在完全m叉树中，其树叶数为t，分枝点数为i，则 (m1)*i=t-1。 证明：
Ch04螺纹联接及螺纹传动-4
螺杆直径和长度、螺距、螺旋线头数、螺母高度。 5、螺纹公差的确定 6、螺旋副零件与滑板联接结构的确定
主要有刚性、弹性和活动联接结构。
三、滑动螺旋传动设计 1、滑动螺旋副的材料和结构
（1）滑动螺旋副的材料 （常用材料见表4-10） 1） 螺杆的材料应具有足够的强度和耐磨性，良好的可加工 性，对于精密传动螺旋，还要求在热处理后有较好的尺寸稳 定性。 2）螺母的材料除要求具有足够的强度外，还要求与螺杆配合 传动时摩擦因数小和耐磨性好，抗胶合能力强。 螺杆的材料：常用35、45号钢;需经热处理以达到高硬度的重 要螺杆，常用合金钢，如65Mn、40Cr、T12、20CrMnTi等。 螺母材料：常用材料有铸造青铜，如ZCuSn10Pb1, ZCuSn5Pb5Zn5；重载低速使用强度较高的铸造青铜ZCuAl10Fe3 或铸造黄铜ZCuZn25Al6Fe3Mn3 ；低速不重要的螺旋传动也可 用耐磨铸铁或灰铸铁。
螺 母
ZcuAl9Fe4Ni4 Mn2 ZCuZn25Al6Fe 3Mn3
注意：①要求强度耐磨性高，配对后f小，加工性好。 ②螺杆硬度高于螺母 （2）滑动螺旋副的结构
滑动螺旋副的结构主要是指螺杆、螺母的固定和支承的结构 形式。螺旋传动的工作刚度与精度等和支承结构有直接关系。
滑动螺旋传动采用梯形、矩形或锯齿形螺纹（多用梯形螺 纹,重载起重螺旋可用锯齿形螺纹, 对效率要求高时可用矩形 螺纹）。 螺母结构： 1）整体式——结构简单，但磨损后精度较差。 2）组合式——磨损后可补偿间隙、精度较高。 3）开合式——适合于双向传动，可提高传动精 度，消除空回误差。
螺距
F F FP p [ p] A d 2 h z d 2 h H
承载螺纹的圈数 一圈螺纹的承载面积
ch04 国际经济学课后答案与习题(萨尔瓦多)
*CHAPTER 4(Core Chapter)THE HECKSCHER-OHLIN AND OTHER TRADE THEORIESOUTLINE4.1 Introduction4.2 Factor Endowments and the Heckscher-Ohlin Theory4.3 The Formal Heckscher-Ohlin ModelCase Study 4-1 The Revealed Comparative Advantage of Various Countries and Regions4.4 Factor-Price Equalization and Income DistributionCase Study 4-2 Has International Trade Increased U.S. Wage Inequalities?4.5 Empirical Tests of the Heckscher-Ohlin Theory4.6 Economies of Scale and International TradeCase Study 4-3 The New International Economies of Scale4.7 Trade Based on Product DifferentiationCase Study 4-4 Growth of Intra-Industry Trade4.8 Technological Gap and Product Cycle ModelsCase Study 4-5: The United States as the Most Competitive Economy in the World4.9 Transportation Costs and International Trade4.10 Environmental Standards and International TradeAppendix The Specific-Factors Model and Intra-Industry Trade ModelsA4.1 The Specific-Factors ModelA4.2 A Model of Intra-Industry TradeKey TermsInternationalofscaleeconomies pricesRelativefactorproducts Heckscher–Ohlin (H–O) theory DifferentiatedtradeIntra-industryHeckscher–Ohlintheorem(H–O)Factor-proportions or factor-endowment theory Technological gap modelcyclemodelProductFactor–price equalization theoremcostsTransportationStolper-Samuelsontheoremmodel Nontraded goods and services Specific-factorsparadox Environmental standardsLeontiefMonopolisticcompetitionscalereturnsIncreasingtoLecture Guide1. This is one of the most important and difficult chapters in the book. It is also a long chapter andrequires four lectures to cover adequately.2. In the first lecture, I would cover sections 1-3. Section 3 is one of the most important sections inthe book because it presents the H-O model. I would proceed slowly and carefully in explaining Figure 4.1 and compare it to the standard trade model of Figure 3.4.3. In the second lecture, I would cover sections 4 and 5. Section 4 on the factor-price equalizationtheorem and income distribution is a difficult section. Case Study 4-2 should be of great interest to the students and give rise to a great deal of class discussion.4. In third lecture, I would cover sections sections 6-7, paying a great deal of attention to section 7on trade in differentiated products.5. In fourth lecture, I would cover the rest of the chapter.Answers to Review Questions and Problems1. a. The Heckscher–Ohlin (H-0) theorem postulates that a nation will export those commodi- ties whose production requires the intensive use of the nation’s relatively abundant and cheap factor and import the commodities whose production requires the intensive useof the nation’s relatively scarce and expensive factor. In short, the relatively labor-richnation exports relatively labor-intensive commodities and imports the relativelycapital-intensive commodities.b. Heckscher and Ohlin identify the relative difference in factor endowments amongnations as the basic determinant of comparative advantage and international trade.c. The H-O Theory represent an extension of the standard trade model because it explains the basis for comparative advantage (classical economists, such as Ricardo had assumed it) and examines the effect of international trade on factor prices and income distribution (which classical economists had left unanswered).2. See Figure 1 on the next page.3. a. The factor–price equalization theorem postulates that international trade will bring about the equalization of the returns to homogeneous or identical factors across nations.b. The Stopler-Samuelson theorem postulates that free international trade reduces the realincome of the nation’s relatively scarce factor and increases the real income of the nation’s relatively abundant factor.Fig 4.1Fig 4.2XXb. The specific-factors model postulates that the opening of trade (1) benefits the specific factorused in the production of the nation’s export commodity, (2) harms the specific factor used in the production of the nation’s import-competing industry, and (3) leads to an ambiguouseffect (i.e., it may benefit or harm) the mobile factor.c. Trade acts as a substitute for the international mobility of factors of production in itseffect on factor prices. With perfect mobility, labor would migrate from the low-wagenation to the high-wage nation until wages in the two nations are equalized. Similarly,capital would move from the low-interest to the high-interest nation until the rate ofinterest was equalized in the two nations.4. a. The Leontief paradox refers to the original Leontief’s finding that U.S. import substituteswere more K-intensive than U.S. exports. This was the opposite of what the H-O theorempostulated.b. The Leontief paradox was resolved by including human capital into the calculations andexcluding industries based on natural resources. Recent research using data on many sectors, for many countries, over many years, and considering that countries could specialize in aparticular subset or group of commodities that were best suited to their specific factorendowments, provides strong support for the H-O theorem.c. The Hecksher-Olhin theory remains the centerpiece of modern trade theory for explaininginternational trade today. To be sure, there are other forces (such as economies of scale,product differentiation, and technological differences across countries) that provide additional reasons and explanations for some international trade not explained by the basic H-O model.These other trade theories complement the basic H-O model in explaining the pattern ofinternational trade in the world today.5. International trade with developing economies, especially newly industrializing economies (NIEs), contributed in two ways to increased wage inequalities between skilled and unskilled workers in the United States during the past two decades. Directly, by reducing the demand for unskilledworkers as a result of increased U.S. imports of labor-intensive manufactures and, indirectly, byspeeding up the introduction of labor-saving innovations, which further reduced the U.S.demand for unskilled workers. International trade, however, was only a small cause of increased wage inequalities in the United States. The most important cause was technological change.6. a. Economies of scale refer to the production situation where output grows proportionatelymore than the increase in inputs or factors of production. For example, output may morethan double with a doubling of inputs.b. Even if two nations were identical in every respect, there is still a basis for mutually bene-ficial trade based on economies of scale. When each nation specializes in the production of one commodity, the combined total world output of both commodities will be greater thanthan without specialization when economies of scale are present. With trade, each nationthen shares in these gains.c. The new international economies of scale refers to the increase in productivity resultingfrom firms purchasing parts and components from nations where they are made cheaperand better, and by establishing production facilities abroad-26-7. a. Product differentiation refers to products that are similar, but not identical. Intra-industrytrade refers to trade in differentiated products, as opposed to inter-industry trade incompletely different products.b. Intra-industry trade arises in order to take advantage of important economies of scale inproduction. That is, with intra-industry trade each firm or plant in industrial countries canspecialize in the production of only one, or at most a few, varieties and styles of the sameproduct rather than many different varieties and styles of a product and achieve economies of scale.c. With few varieties and styles, more specialized and faster machinery can be developedfor a continuous operation and a longer production run. The nation then imports othervarieties and styles from other nations. Intra-industry trade benefits consumers because ofthe wider range of choices (i.e., the greater variety of differentiated products) available atthe lower prices made possible by economies of scale in production.8. a. According to the technological gap model, a firm exports a new product until imitators incountries take away its market. In the meantime, the innovating firm will have introduced a new product or process.b. The criticism of the technological gap model are that it does not explain the size of techno- logical gaps and does not explore the reason for technological gaps arising in the first place, or exactly how they are eliminated over time.c. The five stages of the product cycle model are: the introduction of the product, expansion of production for export, standardization and beginning of production abroad through imitation, foreign imitators underselling the nation in third markets, and foreigners underselling theinnovating firms in their home market as well.9. See Figure 2 on page 25.10. A nation with lower environmental standards can use the environment as a resource endow-ment or as a factor of production in attracting polluting firms from abroad and achieving acomparative advantage in the production of polluting goods and services. This can lead totrade disputes with nations with more stringent environmental standards.-27-Multiple-Choice Questions1. The H-O model extends the classical trade model by:a. explaining the basis for comparative advantageb. examining the effect of trade on factor prices*c. both a and bd. neither a nor b2. A nation is said to have a relative abundance of K if it has a:a. greater absolute amount of Kb. smaller absolute amount of Lc. higher L/K ratio*d. lower price of K in relation to the price of L3. A difference in relative commodity prices between nations can be based on a difference in:a. technologyb. factor endowmentsc. tastes*d. all of the above4. In the H-O model, international trade is based mostly on a difference in:a. technology*b. factor endowmentsc. economies of scaled. tastes5. According to the H-O theory, trade reduces international differences in:a. commodity pricesb. in factor prices*c. both commodity and factor pricesd. neither relative nor absolute factor prices6. According to the Stolper-Samuelson theorem, international trade leads toa. reduction in the real income of the nation’s relatively abundant factor*b. reduction in the real income of the nation’s relatively scarce factorc. increase in the real income of the nation’s relatively scarce factord. none of the above7. Which of the following is false with regard to the specific factors theorem, international trade *a. harms the immobile factors that are specific to the nation’s export commodities or sectorsb. harms the immobile factors that are specific to the nation’s import-competing commoditiesc. has an ambiguous effect on the nation’s mobile factorsd. may benefit or harm the nation’s mobile factors8. Perfect international mobility of factors of productiona. leads to a reduction in international differences in the returns to homogenous factorsb. acts as a substitute for international trade in its effects on factor pricesc. operates on the supply of factors in affecting factor prices*d. all of the above9. The Leontief paradox refers to the empirical finding that U.S.*a. import substitutes were more K-intensive than exportsb. exports were more L-intensive than importsc. exports were more K-intensive than import substitutesd. all of the above10. From empirical studies, we conclude that the H-O theory:a. must be rejectedb. must be accepted without reservations*c. can generally be acceptedd. explains all international trade11. International trade can be based on economies of scale even if both nations have identical:a. factor endowmentsb. tastesc. technology*d. all of the above12. A great deal of international trade:a. is intra-industry tradeb. involves differentiated productsc. is based on monopolistic competition*d. all of the above13. Intra-industry trade takes place:a. because products are homogeneous*b. in order to take advantage of economies of scalec. because perfect competition is the prevalent form of market organizationd. all of the above14. Which of the following statements is true with regard to the product-cycle theory?a. it depends on differences in technological changes over time among countriesb. it depends on the opening and the closing of technological gaps among countriesc. it postulates that industrial countries export more advanced products to lessadvanced countries*d. all of the above15. Transport costs:a. increase the price in the importing countryb. reduces the price in the exporting countryc. falls less heavily on the nation with the more elastic demand and supply curves of the traded commodity*d. all of the above-30-ADDITIONAL ESSAYS AND PROBLEMS FOR PART ONE1. Assume that both the United States and Germany produce beef and computer chips with the following costs:United States Germany(dollars) (marks)Unit cost of beef (B) 2 8Unit cost of computer chips (C) 1 2(a) What is the opportunity cost of beef (B) and computer chips (C) in each country?(b) In which commodity does the United States have a comparative cost advantage?What about Germany?(c) What is the range for mutually beneficial trade between the United States and Germanyfor each computer chip traded?(b) How much would the United States and Germany gain if 1 unit of beef is exchangedfor 3 chips?Answ. (a) In the United States:the opportunity cost of one unit of beef is 2 chips;the opportunity cost of one chip is 1/2 unit of beef.In Germany:the opportunity cost of one unit of beef is 4 chips;the opportunity cost of one chip is 1/4 unit of beef.(b) The United States has a comparative cost advantage in beef with respect to Germany,while Germany has a comparative cost advantage in computer chips.(c) The range for mutually beneficial trade between the United States and Germany foreach unit of beef that the United States exports is2C < 1B < 4C(d) Both the United States and Germany would gain 1 chip for each unit of beef traded.2. Given: (1) two nations (1 and 2) which have the same technology but different factor costs conditions, and (3) no transportation costs, tariffs, or other obstructions to trade.Prove geometrically that mutually advantageous trade between the two nations is possible.Note: Your answer should show the autarky (no-trade) and free-trade points of production and consumption for each nation, the gains from trade of each nation, and express the equilibrium condition that should prevail when trade stops expanding.)Ans.: See the figure below.Fig 4.3Fig 4.4Nations 1 and 2 have different production possibilities curves and different community indifference maps. With these, they will usually end up with different relative commodity prices in autarky, thus making mutually beneficial trade possible.In the figure, Nation 1 produces and consumes at point A and Px/Py=P A in autarky, while Nation 2 produces and consumes at point A' and Px/Py=P A'. Since P A < P A', Nation 1 has a comparative advantage in X and Nation 2 in Y. Specialization in production proceeds until point B in Nation 1 and point B' in Nation 2, at which P B =P B' and the quantity supplied for export of each commodity exactly equals the quantity demanded for import.Thus, Nation 1 starts at point A in production and consumption in autarky, moves to point B in production, and by exchanging BC of X for CE of Y reaches point E in consumption. E > A since it involves more of both X and Y and lies on a higher community indifference curve.Nation 2 starts at A' in production and consumption in autarky, moves to point B' in production, and by exchanging B'C' of Y for C'E' of X reaches point E'in consumption (which exceeds A').At Px/Py=P B =P B', Nation 1 wants to export BC of X for CE of Y, while Nation 2 wants to export B'C' (=CE) of Y for C'E' (=BC) of X. Thus, P B =P B' is the equilibrium relative commodity price because it clears both (the X and Y) markets.3. (a) Identify the conditions that may give rise to trade between two nations. (b) What aresome of the assumptions on which the Heckscher-Ohlin theory is based? (c) What does this theory say about the pattern of trade and effect of trade on factor prices?Ans. (a) Trade can be based on a difference in factor endowments, technology, or tastesbetween two nations. A difference either in factor endowments or technology results in a different production possibilities frontier for each nation, which, unlessneutralized by a difference in tastes, leads to a difference in relative commodity price and mutually beneficial trade. If two nations face increasing costs and have identical production possibilities frontiers but different tastes, there will also be a differencein relative commodity prices and the basis for mutually beneficial trade between the two nations. The difference in relative commodity prices is then translated into adifference in absolute commodity prices between the two nations, which is the immediate cause of trade.(b) The Heckscher-Ohlin theory (sometimes referred to as the modern theory – asopposed to the classical theory - of international trade) assumes that nations have the same tastes, use the same technology, face constant returns to scale (i.e., a givenpercentage increase in all inputs increases output by the same percentage) but differ widely in factor endowments. It also says that in the face of identical tastes or demand conditions, this difference in factor endowments will result in a difference in relative factor prices between nations, which in turn leads to a difference in relativecommodity prices and trade. Thus, in the Heckscher-Ohlin theory, the internationaldifference in supply conditions alone determines the pattern of trade. To be noted is that the two nations need not be identical in other respects in order for internationaltrade to be based primarily on the difference in their factor endowments.(c) The Heckscher-Ohlin theorem postulates that each nation will export the commodityintensive in its relatively abundant and cheap factor and import the commodityintensive in its relatively scarce and expensive factor. As an important corollary, itadds that under highly restrictive assumptions, trade will completely eliminate thepretrade relative and absolute differences in the price of homogeneous factors amongnations. Under less restrictive and more usual conditions, however, trade will reduce, but not eliminate, the pretrade differences in relative and absolute factor prices among nations. In any event, the Heckscher-Ohlin theory does say something very useful onhow trade affects factor prices and the distribution of income in each nation. Classical economists were practically silent on this point.-33-4. Suppose that tastes change in Nation 1 (the L-abundant and L-cheap nation) so that consumers demand more of commodity X (the L-intensive commodity) and less of commodity Y (the K- intensive commodity). Suppose that Nation 1 is India, commodity X is textiles, and commodi- ty Y is food. Starting from the no-trade equilibrium position and using the Heckscher-Ohlinmodel, trace the effect of this change in tastes on India's (a) relative commodity prices anddemand for food and textiles, (b) production of both commodities and factor prices, and(c) comparative advantage and volume of trade. (d) Do you expect international trade to leadto the complete equalization of relative commodity and factor prices between India and theUnited States? Why?Ans. (a) The change in tastes can be visualized by a shift toward the textile axis in India'sindifference map in such a way that an indifference curve is tangent to the steepersegment of India's production frontier (because of increasing opportunity costs) after the increase in demand for textiles. This will cause the pretrade relative commodity price of textiles to rise in India.(b) The increase in the relative price of textiles will lead domestic producers in India toshift labor and capital from the production of food to the production of textiles. Since textiles are L-intensive in relation to food, the demand for labor and therefore the wage rate will rise in India. At the same time, as the demand for food falls, thedemand for and thus the price of capital will fall. With labor becoming relative more expensive, producers in India will substitute capital for labor in the production of both textiles and food.(c) Even with the rise in relative wages and in the relative price of textiles, India stillremains the L-abundant and low-wage nation with respect to a nation such as theUnited States. However, the pretrade difference in the relative price of textilesbetween India and the United States is now somewhat smaller than before the change in tastes in India. As a result the volume of trade required to equalize relativecommodity prices and hence factor prices is smaller than before. That is, India need now export a smaller quantity of textiles and import less food than before for therelative price of textiles in India and the United States to be equalized. Similarly, the gap between real wages and between India and the United States is now smaller and can be more quickly and easily closed (i.e., with a smaller volume of trade).(d) Since many of the assumptions required for the complete equalization of relativecommodity and factor prices do not hold in the real world, great differences can be expected and do in fact remain between real wages in India and the United States.Nevertheless, trade would tend to reduce these differences, and the H-O model does identify the forces that must be considered to analyze the effect of trade on thedifferences in the relative and absolute commodity and factor prices between Indiaand the United States.-34-5. (a) Explain why the Heckscher-Ohlin trade model needs to be extended. (b) Indicate in what important ways the Heckscher-Ohlin trade model can be extended. (c) Explain what ismeant by differentiated products and intra-industry trade.Ans. (a) The Heckscher-Ohlin trade model needs to be extended because, while generallycorrect, it fails to explain a significant portion of international trade, particularly the trade in manufactured products among industrial nations.(b) The international trade left unexplained by the basic Heckscher-Ohlin trade model canbe explained by (1) economies of scale, (2) intra-industry trade, and (3) trade based on imitation gaps and product differentiation.(c) Differentiated products refer to similar, but not identical, products (such as cars,typewriters, cigarettes, soaps, and so on) produced by the same industry or broadproduct group. Intra-industry trade refers to the international trade in differentiated products.-35-。
ch04国际经济学课后答案与习题（萨尔瓦多）
ch04国际经济学课后答案与习题（萨尔⽡多）*CHAPTER 4(Core Chapter)THE HECKSCHER-OHLIN AND OTHER TRADE THEORIESOUTLINE4.1 Introduction4.2 Factor Endowments and the Heckscher-Ohlin Theory4.3 The Formal Heckscher-Ohlin ModelCase Study 4-1 The Revealed Comparative Advantage of Various Countries and Regions4.4 Factor-Price Equalization and Income DistributionCase Study 4-2 Has International Trade Increased U.S. Wage Inequalities?4.5 Empirical Tests of the Heckscher-Ohlin Theory4.6 Economies of Scale and International TradeCase Study 4-3 The New International Economies of Scale4.7 Trade Based on Product DifferentiationCase Study 4-4 Growth of Intra-Industry Trade4.8 Technological Gap and Product Cycle ModelsCase Study 4-5: The United States as the Most Competitive Economy in the World4.9 Transportation Costs and International Trade4.10 Environmental Standards and International TradeAppendix The Specific-Factors Model and Intra-Industry Trade ModelsA4.1 The Specific-Factors ModelA4.2 A Model of Intra-Industry TradeKey TermsInternationalofscaleeconomies pricesRelativefactorproducts Heckscher–Ohlin (H–O) theory DifferentiatedtradeIntra-industryHeckscher–Ohlintheorem(H–O)Factor-proportions or factor-endowment theory Technological gap modelcyclemodelProductFactor–price equalization theoremcostsTransportationStolper-Samuelsontheoremmodel Nontraded goods and services Specific-factorsparadox Environmental standardsLeontiefMonopolisticcompetitionscalereturnsIncreasingtoLecture Guide1. This is one of the most important and difficult chapters in the book. It is also a long chapter andrequires four lectures to cover adequately.2. In the first lecture, I would cover sections 1-3. Section 3 is one of the most important sections inthe book because it presents the H-O model. I would proceed slowly and carefully in explaining Figure 4.1 and compare it to the standard trade model of Figure 3.4.3. In the second lecture, I would cover sections 4 and 5. Section 4 on the factor-price equalizationtheorem and income distribution is a difficult section. Case Study 4-2 should be of great interest to the students and give rise to a great deal of class discussion.4. In third lecture, I would cover sections sections 6-7, paying a great deal of attention to section 7on trade in differentiated products.5. In fourth lecture, I would cover the rest of the chapter.Answers to Review Questions and Problems1. a. The Heckscher–Ohlin (H-0) theorem postulates that a nation will export those commodi- ties whose production requires the intensive use of the nation’s relatively abundant and cheap factor and import the commodities whose production requires the intensive useof the nation’s relatively scarce and expensive factor. In short, the relatively labor-richnation exports relatively labor-intensive commodities and imports the relativelycapital-intensive commodities.b. Heckscher and Ohlin identify the relative difference in factor endowments amongnations as the basic determinant of comparative advantage and international trade.c. The H-O Theory represent an extension of the standard trade model because it explains the basis for comparative advantage (classical economists, such as Ricardo had assumed it) and examines the effect of international trade on factor prices and income distribution (which classical economists had left unanswered).2. See Figure 1 on the next page.3. a. The factor–price equalization theorem postulates that international trade will bring about the equalization of the returns to homogeneous or identical factors across nations.b. The Stopler-Samuelson theorem postulates that free international trade reduces the realincome of the nation’s relatively scarce factor and increases the real income of the nation’s relatively abundant factor.Fig 4.1Fig 4.2XXb. The specific-factors model postulates that the opening of trade (1) benefits the specific factorused in the production of the nation’s export commodity, (2) harms the specific factor used in the production of the nation’s import-competing industry, and (3) leads to an ambiguouseffect (i.e., it may benefit or harm) the mobile factor.c. Trade acts as a substitute for the international mobility of factors of production in itseffect on factor prices. With perfect mobility, labor would migrate from the low-wagenation to the high-wage nation until wages in the two nations are equalized. Similarly,capital would move from the low-interest to the high-interest nation until the rate ofinterest was equalized in the two nations.4. a. The Leontief paradox refers to the original Leontief’s finding that U.S. import substituteswere more K-intensive than U.S. exports. This was the opposite of what the H-O theorempostulated.b. The Leontief paradox was resolved by including human capital into the calculations andexcluding industries based on natural resources. Recent research using data on many sectors, for many countries, over many years, and considering that countries could specialize in aparticular subset or group of commodities that were best suited to their specific factorendowments, provides strong support for the H-O theorem.c. The Hecksher-Olhin theory remains the centerpiece of modern trade theory for explaininginternational trade today. To be sure, there are other forces (such as economies of scale,product differentiation, and technological differences across countries) that provide additional reasons and explanations for some international trade not explained by the basic H-O model.These other trade theories complement the basic H-O model in explaining the pattern ofinternational trade in the world today.5. International trade with developing economies, especially newly industrializing economies (NIEs), contributed in two ways to increased wage inequalities between skilled and unskilled workers in the United States during the past two decades. Directly, by reducing the demand for unskilledworkers as a result of increased U.S. imports of labor-intensive manufactures and, indirectly, byspeeding up the introduction of labor-saving innovations, which further reduced the U.S.demand for unskilled workers. International trade, however, was only a small cause of increased wage inequalities in the United States. The most important cause was technological change.6. a. Economies of scale refer to the production situation where output grows proportionatelymore than the increase in inputs or factors of production. For example, output may morethan double with a doubling of inputs.b. Even if two nations were identical in every respect, there is still a basis for mutually bene-ficial trade based on economies of scale. When each nation specializes in the production of one commodity, the combined total world output of both commodities will be greater thanthan without specialization when economies of scale are present. With trade, each nationthen shares in these gains.c. The new international economies of scale refers to the increase in productivity resultingfrom firms purchasing parts and components from nations where they are made cheaperand better, and by establishing production facilities abroad-26-7. a. Product differentiation refers to products that are similar, but not identical. Intra-industrytrade refers to trade in differentiated products, as opposed to inter-industry trade incompletely different products.b. Intra-industry trade arises in order to take advantage of important economies of scale inproduction. That is, with intra-industry trade each firm or plant in industrial countries canspecialize in the production of only one, or at most a few, varieties and styles of the sameproduct rather than many different varieties and styles of a product and achieve economies of scale.c. With few varieties and styles, more specialized and faster machinery can be developedfor a continuous operation and a longer production run. The nation then imports othervarieties and styles from other nations. Intra-industry trade benefits consumers because ofthe wider range of choices (i.e., the greater variety of differentiated products) available atthe lower prices made possible by economies of scale in production.8. a. According to the technological gap model, a firm exports a new product until imitators incountries take away its market. In the meantime, the innovating firm will have introduced a new product or process. b. The criticism of the technological gap model are that it does not explain the size of techno- logical gaps and does not explore the reason for technological gaps arising in the first place, or exactly how they are eliminated over time.c. The five stages of the product cycle model are: the introduction of the product, expansion of production for export, standardization and beginning of production abroad through imitation, foreign imitators underselling the nation in third markets, and foreigners underselling theinnovating firms in their home market as well.9. See Figure 2 on page 25.10. A nation with lower environmental standards can use the environment as a resource endow-ment or as a factor of production in attracting polluting firms from abroad and achieving acomparative advantage in the production of polluting goods and services. This can lead totrade disputes with nations with more stringent environmental standards.-27-Multiple-Choice Questions1. The H-O model extends the classical trade model by:a. explaining the basis for comparative advantageb. examining the effect of trade on factor prices*c. both a and bd. neither a nor b2. A nation is said to have a relative abundance of K if it has a:a. greater absolute amount of Kb. smaller absolute amount of Lc. higher L/K ratio*d. lower price of K in relation to the price of L3. A difference in relative commodity prices between nations can be based on a difference in:a. technologyb. factor endowmentsc. tastes*d. all of the above4. In the H-O model, international trade is based mostly on a difference in:a. technology*b. factor endowmentsc. economies of scaled. tastes5. According to the H-O theory, trade reduces international differences in:a. commodity pricesb. in factor prices*c. both commodity and factor pricesd. neither relative nor absolute factor prices6. According to the Stolper-Samuelson theorem, international trade leads toa. reduction in the real income of the nation’s relatively abundant factor*b. reduction in the real income of the nation’s relatively scarce factorc. increase in the real income of the nation’s relatively scarce factord. none of the above7. Which of the following is false with regard to the specific factors theorem, international trade *a. harms the immobile factors that are specific to the nation’s export commodities or sectorsb. harms the immobile factors that are specific to the nation’s import-competing commoditiesc. has an ambiguous effect on the nation’s mobile factorsd. may benefit or harm the nation’s mobile factors8. Perfect international mobility of factors of productiona. leads to a reduction in international differences in the returns to homogenous factorsb. acts as a substitute for international trade in its effects on factor pricesc. operates on the supply of factors in affecting factor prices*d. all of the above9. The Leontief paradox refers to the empirical finding that U.S.*a. import substitutes were more K-intensive than exportsb. exports were more L-intensive than importsc. exports were more K-intensive than import substitutesd. all of the above10. From empirical studies, we conclude that the H-O theory:a. must be rejectedb. must be accepted without reservations*c. can generally be acceptedd. explains all international trade11. International trade can be based on economies of scale even if both nations have identical:a. factor endowmentsb. tastesc. technology*d. all of the above12. A great deal of international trade:a. is intra-industry tradeb. involves differentiated productsc. is based on monopolistic competition*d. all of the above13. Intra-industry trade takes place:a. because products are homogeneous*b. in order to take advantage of economies of scalec. because perfect competition is the prevalent form of market organizationd. all of the above14. Which of the following statements is true with regard to the product-cycle theory?a. it depends on differences in technological changes over time among countriesb. it depends on the opening and the closing of technological gaps among countriesc. it postulates that industrial countries export more advanced products to lessadvanced countries*d. all of the above15. Transport costs:a. increase the price in the importing countryb. reduces the price in the exporting countryc. falls less heavily on the nation with the more elastic demand and supply curves of the traded commodity*d. all of the above-30-ADDITIONAL ESSAYS AND PROBLEMS FOR PART ONE1. Assume that both the United States and Germany produce beef and computer chips with the following costs: United States Germany(dollars) (marks)Unit cost of beef (B) 2 8Unit cost of computer chips (C) 1 2(a) What is the opportunity cost of beef (B) and computer chips (C) in each country?(b) In which commodity does the United States have a comparative cost advantage?What about Germany?(c) What is the range for mutually beneficial trade between the United States and Germanyfor each computer chip traded?(b) How much would the United States and Germany gain if 1 unit of beef is exchangedfor 3 chips?Answ. (a) In the United States:the opportunity cost of one unit of beef is 2 chips;the opportunity cost of one chip is 1/2 unit of beef.In Germany:the opportunity cost of one unit of beef is 4 chips;the opportunity cost of one chip is 1/4 unit of beef.(b) The United States has a comparative cost advantage in beef with respect to Germany,while Germany has a comparative cost advantage in computer chips.(c) The range for mutually beneficial trade between the United States and Germany foreach unit of beef that the United States exports is2C < 1B < 4C(d) Both the United States and Germany would gain 1 chip for each unit of beef traded.2. Given: (1) two nations (1 and 2) which have the same technology but different factor costs conditions, and (3) no transportation costs, tariffs, or other obstructions to trade.Prove geometrically that mutually advantageous trade between the two nations is possible.Note: Your answer should show the autarky (no-trade) and free-trade points of production and consumption for each nation, the gains from trade of each nation, and express the equilibrium condition that should prevail when trade stops expanding.) Ans.: See the figure below.Fig 4.3Fig 4.4Nations 1 and 2 have different production possibilities curves and different community indifference maps. With these, they will usually end up with different relative commodity prices in autarky, thus making mutually beneficial trade possible.In the figure, Nation 1 produces and consumes at point A and Px/Py=P A in autarky, while Nation 2 produces and consumes at point A' and Px/Py=P A'. Since P A < P A', Nation 1 has a comparative advantage in X and Nation 2 in Y. Specialization in production proceeds until point B in Nation 1 and point B' in Nation 2, at which P B =P B' and the quantity supplied for export of each commodity exactly equals the quantity demanded for import.Thus, Nation 1 starts at point A in production and consumption in autarky, moves to point B in production, and by exchanging BC of X for CE of Y reaches point E in consumption. E > A since it involves more of both X and Y and lies on a higher community indifference curve.Nation 2 starts at A' in production and consumption in autarky, moves to point B' in production, and by exchanging B'C' of Y for C'E' of X reaches point E'in consumption (which exceeds A').At Px/Py=P B =P B', Nation 1 wants to export BC of X for CE of Y, while Nation 2 wants to export B'C' (=CE) of Y for C'E' (=BC) of X. Thus, P B =P B' is the equilibrium relative commodity price because it clears both (the X and Y) markets.3. (a) Identify the conditions that may give rise to trade between two nations. (b) What aresome of the assumptions on which the Heckscher-Ohlin theory is based? (c) What does this theory say about the pattern of trade and effect of trade on factor prices?Ans. (a) Trade can be based on a difference in factor endowments, technology, or tastesbetween two nations. A difference either in factor endowments or technology results in a different production possibilities frontier for each nation, which, unlessneutralized by a difference in tastes, leads to a difference in relative commodity price and mutually beneficial trade. If two nations face increasing costs and have identical production possibilities frontiers but different tastes, there will also be a differencein relative commodity prices and the basis for mutually beneficial trade between the two nations. The difference in relative commodity prices is then translated into adifference in absolute commodity prices between the two nations, which is the immediate cause of trade.(b) The Heckscher-Ohlin theory (sometimes referred to as the modern theory – asopposed to the classical theory - of international trade) assumes that nations have the same tastes, use the same technology, face constant returns to scale (i.e., a givenpercentage increase in all inputs increases output by the same percentage) but differ widely in factor endowments. It also says that in the face of identical tastes or demand conditions, this difference in factor endowments will result in a difference in relative factor prices between nations, which in turn leads to a difference in relativecommodity prices and trade. Thus, in the Heckscher-Ohlin theory, the internationaldifference in supply conditions alone determines the pattern of trade. To be noted is that the two nations need not be identical in other respects in order for internationaltrade to be based primarily on the difference in their factor endowments.(c) The Heckscher-Ohlin theorem postulates that each nation will export the commodityintensive in its relatively abundant and cheap factor and import the commodityintensive in its relatively scarce and expensive factor. As an important corollary, itadds that under highly restrictive assumptions, trade will completely eliminate thepretrade relative and absolute differences in the price of homogeneous factors amongnations. Under less restrictive and more usual conditions, however, trade will reduce, but not eliminate, the pretrade differences in relative and absolute factor prices among nations. In any event, the Heckscher-Ohlin theory does say something very useful onhow trade affects factor prices and the distribution of income in each nation. Classical economists were practically silent on this point.4. Suppose that tastes change in Nation 1 (the L-abundant and L-cheap nation) so that consumers demand more of commodity X (the L-intensive commodity) and less of commodity Y (the K- intensive commodity). Suppose that Nation 1 is India, commodity X is textiles, and commodi- ty Y is food. Starting from the no-trade equilibrium position and using the Heckscher-Ohlinmodel, trace the effect of this change in tastes on India's (a) relative commodity prices anddemand for food and textiles, (b) production of both commodities and factor prices, and(c) comparative advantage and volume of trade. (d) Do you expect international trade to leadto the complete equalization of relative commodity and factor prices between India and theUnited States? Why?Ans. (a) The change in tastes can be visualized by a shift toward the textile axis in India'sindifference map in such a way that an indifference curve is tangent to the steepersegment of India's production frontier (because of increasing opportunity costs) after the increase in demand for textiles. This will cause the pretrade relative commodity price of textiles to rise in India.(b) The increase in the relative price of textiles will lead domestic producers in India toshift labor and capital from the production of food to the production of textiles. Since textiles are L-intensive in relation to food, the demand for labor and therefore the wage rate will rise in India. At the same time, as the demand for food falls, thedemand for and thus the price of capital will fall. With labor becoming relative more expensive, producers in India will substitute capital for labor in the production of both textiles and food.(c) Even with the rise in relative wages and in the relative price of textiles, India stillremains the L-abundant and low-wage nation with respect to a nation such as theUnited States. However, the pretrade difference in the relative price of textilesbetween India and the United States is now somewhat smaller than before the change in tastes in India. As a result the volume of trade required to equalize relativecommodity prices and hence factor prices is smaller than before. That is, India need now export a smaller quantity of textiles and import less food than before for therelative price of textiles in India and the United States to be equalized. Similarly, the gap between real wages and between India and the United States is now smaller and can be more quickly and easily closed (i.e., with a smaller volume of trade).(d) Since many of the assumptions required for the complete equalization of relativecommodity and factor prices do not hold in the real world, great differences can be expected and do in fact remain between real wages in India and the United States.Nevertheless, trade would tend to reduce these differences, and the H-O model does identify the forces that must be considered to analyze the effect of trade on thedifferences in the relative and absolute commodity and factor prices between Indiaand the United States.5. (a) Explain why the Heckscher-Ohlin trade model needs to be extended. (b) Indicate in what important ways the Heckscher-Ohlin trade model can be extended. (c) Explain what ismeant by differentiated products and intra-industry trade.Ans. (a) The Heckscher-Ohlin trade model needs to be extended because, while generallycorrect, it fails to explain a significant portion of international trade, particularly the trade in manufactured products among industrial nations.(b) The international trade left unexplained by the basic Heckscher-Ohlin trade model canbe explained by (1) economies of scale, (2) intra-industry trade, and (3) trade based on imitation gaps and product differentiation.(c) Differentiated products refer to similar, but not identical, products (such as cars,typewriters, cigarettes, soaps, and so on) produced by the same industry or broadproduct group. Intra-industry trade refers to the international trade in differentiated products.。
ch04 苯系物含量的气相色谱法测定
• 2.校正因子测定及定性分析 （1）在最佳柱温下，用1µL微量注射器分 别取纯苯、甲苯和二甲苯各0.5µL进样，记 录色谱图中各色谱峰保留时间，与步骤（5） 所得结果相比较，进行定性分析。 （2）取一支1µL微量注射器取混合标样 0.5µL进样，记录各峰的峰面积和保留时间， 重复测定两三次，计算各组分的校正因子。
八、苯系物含量的气相色谱法测定
（一）、实验目的
掌握气相色谱分离的基本原理和色谱分析的基本 工作方法。 掌握保留值的测定及用保留值定性的方法。 学习校正因子的测定和校正归一化法定量的方法。
（二）实验原理 • 气相色谱的流动相为惰性气体，具有一 定活性的吸附剂作为固定相。当多组分的 混合样品进入色谱柱后，由于吸附剂对每 个组分的吸附力不同，经过一定时间后， 各组分在色谱柱中的运行速度也就不同。 吸附力弱的组分容易被解吸下来，最先离 开色谱柱进入检测器，而吸附力最强的组 分最不容易被解吸下来，因此最后离开色 谱柱。如此，各组分得以在色谱柱中彼此 分离，顺序进入检测器中被检测、记录下 来。
（七）仪器操作规程
1打开稳压电源； 2打开氮气阀，打开净化器上的载气开关阀，然后检查是 否漏气，保证气密性良好； 3调节总流量为适当值（根据刻度的流量表测得）； 4调节分流阀使分流流量为实验所需的流量（用皂膜流量 计在气路系统面板上实际测量），柱流量即为总流量减去 分流量； 5打开空气、氢气开关阀，调节空气、氢气流量为适当值； 6根据实验需要设臵柱温、进样口温度和FID检测器温度； 7打开计算机与工作站； 8FID检测器温度达到150℃以上，按FIRE键点燃FID检 测器火焰； 9设臵FID检测器灵敏度和输出信号衰减； 10待所设参数达到设臵时，即可进样分析； 11实验完毕后，先关闭氢气与空气，用氮气将色谱柱吹净 后关机。
ch04 理解利率 双语分析
payment loan might require you to pay $126
every year for 25 years.
Slide 4–16
• 3. A coupon bond 息票债券 pays the owner of the bond a fixed interest payment (coupon payment) every year until the maturity date, when a specified final amount (face value or par value 面值) is repaid.息票债券持有人在到 期前定期（每年、半年或每季）要得到定额的利 息支付，到期则要收回票面金额和到期当年的利 息支付。 • The coupon payment is so named because the bondholder used to obtain payment by clipping a coupon off the bond and sending it to the bond issuer, who then sent the payment to the holder. Nowadays, it is no longer necessary to send in coupons to receive these payments.
Slide 4–19
• These four types of instruments require payments at different times: Simple loans and discount bonds make payment only at their maturity dates, whereas fixed-payment loans and coupon bonds have payments periodically until maturity. • How would you decide which of these instruments provides you with more income? • To solve this problem, we use the concept of present value, explained earlier, to provide us with a procedure for measuring interest rates on these different types of instruments.
机械制造基础ch04机床基本知识
5 . 按机床主要工作部件的数目可分为：
单轴（single axle） 多轴（multi spindle） 单刀（single-tool） 多刀机床（multi-cutter machine tool）
机床数控化引起机床传统分类方法发生变化， 主要表现在机床品种不是越分越细，而应是趋 向综合。
二、 机床型号编制方法: （regimentation method of machine tool’s model number）
其中：
1）有（ ）的代号或数字，当无内容时则不表示， 若有内容则不带括号；
2）有○符号者，为大写的汉语拼音字母；
3）有△符号者，为阿拉伯数字；
4）有 ○△ 符号者，为大写的汉语拼音字母或者为阿
拉伯数字、或两者兼有之。
通用机床型号辅助部分:
基本部分/ （ Δ ）（- Δ ）
其它特性代号 企业代号
例1： CA6140型卧式车床
2、
联系复合运动之内的各个分解部分，因而传动链所 联系的执行件相互之间的相对速度（相对位移量）有严 格的要求，以保证运动的轨迹。
在内联系传动链中，不应有摩擦传动或是瞬时传动 比变化的传动件（如链传动）。
注：
有几个简单运动就有几个外联系传动链，它们可以有 各自的运动源，也可共用一个运动源。 内联系传动链本身不能提供运动，需要有外联系传动 链将运动源传到内联系传动链上来。 如果外联系传动链与内联系传动链有公用段，内、外传动 链的换置器官（机构）不应布置在公共段。
三、传动原理图
定比机构：传动比固定的传动机构。 换置机构：变换传动比的传动机构。
用一些简明的符号把传动原理和传动路 线表示出来，就是传动原理图。
例：卧式车床的传动原理图
ch04(监测与诊断系统)解读
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B） 放大器和预处理器 放大器和预处理器用来调整由传感器输出的电信号的大小 和输出阻抗等。
C） A／D接口板 A／D接口板主要功能是将信号从连续量变为一个个的离 散数字量。A／D接口板可以同时完成对多路信号的转换(采 样 )。 D）开关量板 用于离散信号。 E）微型计算机 计算机是监测与诊断系统的心脏，负责完成信号的接收、储 存、转换和控制等工作。还可以将信号及分析处理结果显示和 打印出来。
27
例2：风机在线监测系统
28
《易》曰：天道亏盈而益谦，地道变盈而流谦。
风机一般有大直径的转子，以700一900r／m的转速支承在 结构钢或混凝土地基架座上的轴承中运转。一般，这类风机 的主要故障是由于不均匀的结垢或沉结材料跌落引起的不平 衡和不同轴。其全部特征是在运转频率附近的振动变化。在 这种系统中，为显示轴运动，在各个轴承上装了测振传感器。 用一台双通道电荷故大器对两个传惑器输出信号予以放大。 经滤波器滤波后将信号送入微机系统。 两个轴承的温度监测由铜电阻为敏感元件构成的传感器来 完成。并通过放大器将信号送入微机。微机通过振动信号和 温度信号的变化而识别风机的运转状态。
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F） 磁带记录仪 用磁带记录仪定期到现场记录信号，然后带回来重放并进 行分析。便于离线分析。
G） 示波器
H） 滤波器 由传感器输出的振动信号中包含的频率成分比较复杂，频 率范围也较宽，但有些频率成分是我们不感兴趣的，如高频 噪声干扰信号。因此要用滤波器对传感器输出的信号“过 滤”，除掉一些我们不感兴趣的频率成分，然后送入计算机 处理。
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（2） 数据采集系统的工作步骤 A） 组态 组态即选定被监测对象，选定测点，确定巡检的路线和周期， 确定测量参数，并把这些信息输入计算机。 B） 巡检准备 巡检之前把数据采集系统与计算机联接起来，使用相应的软 件使采集系统处于准备状态，使内存清零，把采集系统的时钟 与计算机时钟对准，标定准确的采祥时间。把巡检路线和测点 参数等组态信息输入采集系统。
Ch04.程序流程和异常处理
循环条件(condition)成立？ True 循环体
False
改变循环控制变量 (iterator)
for语句的后继语句
4.3.2 while循环
• • • • • •
False while(条件表达式) 条件表达式？ { True 循环体 循环体语句序列; } while语句的后继语句 说明1~4 【例4.12】利用while循环求1+2+…+100 ，以及1~100 中所有奇数的和、偶数的和 • 【例4.13】求1+2+……的和，直至和>3000为止 • 【例4.14】用近似公式求自然对数的底数e的值，直到 最后一项的绝对值小于10-6为止
4.2.2 switch语句
• switch语句是一个控制语句，它通过将控 制传递给其体内的一个case语句来处理多 个选择和枚举
控制表达式 取值1 语句块1 取值2 语句块2
…… ……
取值n 语句块n
其他 语句块n+1
• 说明1~9
4.3 循环结构
• C#提供了4种不同的循环机制
– – – – for while do...while foreach
4.5 异常处理
• C#中的异常用于处理系统级和应用程序级的错误状态，例如：零 除异常、下标越界、I/O错误等 • 通过使用try语句来定义代码块，实现尝试可能未成功的操作、处 理失败，以及在事后清理资源等 • try • { • // 可能引发异常的语句 • } • catch (异常类型 异常变量) • { • // 在异常发生时执行的代码 • } • finally • { • // 最终必须执行的代码（即使发生异常），如释放资源等 • }
ch04国际经济学课后答案与习题萨尔瓦多
ch04国际经济学课后答案与习题萨尔瓦多萨尔瓦多：国际经济学课后答案与习题第一章介绍国际经济学1. 概念与定义国际经济学是研究国际贸易、国际金融和国际投资等国际经济关系的学科。
它主要研究不同国家之间的贸易、资金流动和其他经济交往，探讨国际经济活动的原因、影响因素和政策措施。
2. 国际经济学的重要性国际经济学旨在帮助人们更好地理解国际经济交往的现象和规律，为国家、企业和个人提供参考依据。
它能揭示经济全球化的趋势、国际贸易的利益和风险，并提供决策者制定政策的理论支持。
第二章国际贸易1. 比较优势理论比较优势理论由大卫·里卡多提出，它认为国家应专注于生产自己具有比较优势的商品，然后通过国际贸易以获取其他商品。
这个理论说明了国际贸易的潜在益处。
2. 绝对优势与比较优势绝对优势是指某个国家在生产某种商品上的效率高于其他国家，而比较优势则是指某个国家在生产某种商品上的机会成本低于其他国家。
比较优势是基于机会成本而产生的。
第三章国际金融1. 汇率与汇率制度汇率是一种货币兑换为另一种货币的比率。
汇率制度是指国家对其货币与其他货币之间的兑换比率进行管理和调整的体系。
汇率制度根据不同的货币政策和国家经济状况而有所不同，如固定汇率制和浮动汇率制等。
2. 随机汇率与管理型汇率制度随机汇率是由市场力量决定的汇率，在市场上自由浮动。
管理型汇率制度是由政府或央行干预市场来控制或影响汇率的变动。
第四章国际投资1. 直接投资与证券投资直接投资是指投资者通过购买或建立企业、工厂或设施等方式，在境外进行经济活动。
证券投资则是指投资者通过购买股票、债券或其他金融资产来获得收益。
2. 外国企业与政府投资外国企业可以通过直接投资的方式，在其他国家建立子公司或扩大在其它国家的经营规模。
政府投资则是指政府通过直接投资的方式，参与国际投资活动，以增加国家的影响力和经济实力。
结语国际经济学是一门重要的学科，它帮助我们理解国际经济交往的规律，为决策者制定政策提供理论支持。
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4字符串数组、元胞数组和构架数组4.1字符串数组4.1.1字符串入门【*例4.1.1-1】先请读者实际操作本例，以体会数值量与字符串的区别。
clear %清除所有内存变量a=12345.6789 %给变量a赋数值标量class(a) %对变量a的类别进行判断a_s=size(a) %数值数组a的“大小”a =1.2346e+004ans =doublea_s =1 1b='S' %给变量b赋字符标量（即单个字符）class(b) %对变量b的类别进行判断b_s=size(b) %符号数组b的“大小”b =Sans =charb_s =1 1whos %观察变量a,b在内存中所占字节Name Size Bytes Classa 1x1 8 double arraya_s 1x2 16 double arrayans 1x4 8 char arrayb 1x1 2 char arrayb_s 1x2 16 double arrayGrand total is 10 elements using 50 bytes4.1.2串数组的属性和标识【*例4.1.2-1】本例演示：串的基本属性、标识和简单操作。
（1）创建串数组a='This is an example.'a =This is an example.（2）串数组a的大小size(a)ans =1 19（3）串数组的元素标识a14=a(1:4) %提出一个子字符串ra=a(end:-1:1) %字符串的倒排a14 =Thisra =.elpmaxe na si sihT（4）串数组的ASCII码ascii_a=double(a) %产生ASCII码ascii_a =Columns 1 through 1284 104 105 115 32 105 115 32 97 110 32 101 Columns 13 through 19120 97 109 112 108 101 46char(ascii_a) %把ASCII码变回字符串ans =This is an example.（5）对字符串ASCII码数组的操作%使字符串中字母全部大写w=find(a>='a'&a<='z'); %找出串数组a中，小写字母的元素位置。
ascii_a(w)=ascii_a(w)-32; %大小写字母ASCII值差32.用数值加法改变部分码值。
char(ascii_a) %把新的ASCII码翻成字符ans =THIS IS AN EXAMPLE.（6）中文字符串数组A='这是一个算例。
'; %创建中文字符串A_s=size(A) %串数组的大小A56=A([5 6]) %取串的子数组ASCII_A=double(A) %获取ASCII码A_s =1 7A56 =算例ASCII_A =Columns 1 through 654754 51911 53947 47350 52195 49405 Column 741379char(ASCII_A) %把ASCII码翻译成字符ans =这是一个算例。
（7）创建带单引号的字符串b='Example ''4.1.2-1'''b =Example '4.1.2-1'（8）由小串构成长串ab=[a(1:7),' ',b,' .'] %这里第2个输入为空格串 ab =This is Example '4.1.2-1' .4.1.3 复杂串数组的创建 4.1.3.1 多行串数组的直接创建【*例4.1.3.1-1】多行串数组的直接输入示例。
clearS=['This string array ' 'has multiple rows.'] S =This string array has multiple rows. size(S) ans =2 184.1.3.2 利用串操作函数创建多行串数组【*例4.1.3.2-1】演示：用专门函数char , str2mat , strvcat 创建多行串数组示例。
S1=char('This string array','has two rows.')S1 =This string array has two rows.S2=str2mat('这','字符','串数组','由4行组成') S2 = 这 字符 串数组由4行组成S3=strvcat('这','字符','串数组',' ','由4行组成')%“空串”会产生一个空格行 S3 = 这 字符 串数组由4行组成 size(S3) ans =5 54.1.3.3 转换函数产生数码字符串【*例4.1.3.3-1】最常用的数组/字符串转换函数int2str , num2str , mat2str 示例。
（1）int2str 把整数数组转换成串数组（非整数将被四舍五入园整后再转换）A=eye(2,4);%生成一个)42(⨯数值数组A_str1=int2str(A) %转换成)102(⨯串数组。
请读者自己用size 检验。
A_str1 = 1 0 0 00 1 0 0（2）num2str把非整数数组转换为串数组（常用于图形中，数据点的标识）rand('state',0)B=rand(2,4); %生成数值矩阵B3=num2str(B,3) %保持3位有效数字，转换为串B3 =0.95 0.607 0.891 0.4560.231 0.486 0.762 0.0185（3）mat2str把数值数组转换成输入形态的串数组（常与eval指令配用）B_str=mat2str(B,4) %保持4位有效数字，转换为“数组输入形式”串B_str =[0.9501 0.6068 0.8913 0.4565;0.2311 0.486 0.7621 0.0185]Expression=['exp(-',B_str,')']; %相当于指令窗写一个表达式exp(-B_str) eval(Expression) %把exp(-B_str)送去执行ans =0.3867 0.5451 0.4101 0.63350.7937 0.6151 0.4667 0.9817【*例4.1.3.3-2】综合例题：在MATLAB计算生成的图形上标出图名和最大值点坐标。
clear %清除内存中的所有变量a=2; %设置衰减系数w=3; %设置振荡频率t=0:0.01:10; %取自变量采样数组y=exp(-a*t).*sin(w*t); %计算函数值，产生函数数组[y_max,i_max]=max(y); %找最大值元素位置t_text=['t=',num2str(t(i_max))]; %生成最大值点的横坐标字符串<7>y_text=['y=',num2str(y_max)]; %生成最大值点的纵坐标字符串<8>max_text=char('maximum',t_text,y_text);%生成标志最大值点的字符串<9>%生成标志图名用的字符串tit=['y=exp(-',num2str(a),'t)*sin(',num2str(w),'t)']; %<11> plot(t,zeros(size(t)),'k') %画纵坐标为0的基准线hold on %保持绘制的线不被清除plot(t,y,'b') %用兰色画y(t)曲线plot(t(i_max),y_max,'r.','MarkerSize',20) %用大红点标最大值点text(t(i_max)+0.3,y_max+0.05,max_text) %在图上书写最大值点的数据值<16>图 4.1.3.3-1 字符串运用示意图4.1.3.4利用元胞数组创建复杂字符串【*例4.1.3.4-1】元胞数组在存放和操作字符串上的应用。
a='MATLAB 5 ';b='introduces new data types:'; %创建单行字符串a,bc1='◆Multidimensional array';c2='◆User-definable data structure'; c3='◆Cell arrays';c4='◆Character array';c=char(c1,c2,c3,c4); %创建多行字符串cC={a;b;c}; %利用元胞数组存放长短不同的字符串<5> disp([C{1:2}]) %显示前两个元胞中的字符内容<6>disp(' ') %显示一行空白disp(C{3}) %显示第3个元胞中的字符内容<8> MATLAB 5 introduces new data types:◆Multidimensional array◆User-definable data structure◆Cell arrays◆Character array4.1.4串转换函数【*例4.1.4-1】fprintf, sprintf, sscanf的用法示例。
2(⨯随机阵rand('state',0);a=rand(2,2); %产生)2s1=num2str(a) %把数值数组转换为串数组s_s=sprintf('%.10e\n',a) %10数位科学记述串,每写一个元素就换行。
s1 =0.95013 0.606840.23114 0.48598s_s =9.5012928515e-0012.3113851357e-0016.0684258354e-0014.8598246871e-001fprintf('%.5g\\',a) %以5位数位最短形式显示。
不能赋值用0.95013\0.23114\0.60684\0.48598\3(⨯数值数组。