开展设计性实验的尝试

机械原理课程实验中,开展设计性实验使我们看到了机械原理课程的实验特色和学生对设计性实验的确实需要.设计性实验不仅能激发出学生的强烈的学习兴趣和创造意识,还能有效的培养学生从事科学实践活动的能力.设计性和综合性实验必将在实验教学改革中成为实验教学的主要环节.     

对我国居民消费增长的利率弹性的实证分析

本文运用 1978～ 2 0 0 1年间的相关数据 ,在分别考察了城市和农村居民消费行为的基础上 ,对我国居民消费行为的利率弹性作出定量分析 ,得出我国居民的消费行为对利率具有一定的敏感性的结论。文章最后指出了一些影响我国利率政策消费弹性的原因 ,这些原因主要有 :我国居民收入差距扩大、生活中的不确定性因素增强、利率的收入效应以及消费结构的改变等     

An Analysis of the Peer Effects in Charitable Giving: The Case of Taiwan

The purpose of this study was to utilize the data from the Survey on Family Income and Expenditure in Taiwan to investigate the influence of peer effects on the behavior of charitable giving. Based on the definitions of the reference group in this study, the estimation results suggested that peer effects on households' decisions on both whether to make charitable giving and how much to contribute were quite modest. The study also found that the price elasticity and the income elasticity of charitable giving in Taiwan were larger than those in the U.S., which may partially explain the low ratio of charitable giving to GDP in Taiwan. The earthquake in 1999 substantially increased the amount of charitable giving though its effect diminished after sometime.     

奥尔森的后现代主义诗论、诗作与量子力学

现代科学的种种新论对后现代主义文学影响巨大 ,量子力学对奥尔森的放射诗论及诗作的影响是一个典型的例子。放射诗提出一种客体主义的理论 ,把诗看作一个开放场和高能结构 ,在时空和自我意识诸方面具有高度的动态性和不确定性 ;把诗人看作一个诗的能量传递和放射链条中的中介环节     

基于生产主体经济视角的水禽供给研究

运用Nerlove模型对1997-2011年我国鸭肉年产量和市场价格的年度数据进行了实证分析。结果表明,肉鸭的短期供给弹性为0.139 0,长期供给弹性为0.663 5,表现为长期弹性大于短期弹性,且二者弹性值均小于1。基于生产主体经济视角,讨论了水禽产业供给特点的成因。提出了促进水禽产业持续和稳定发展的政策建议:依托技术进步提高生产率;完善水禽产业数据库;提高水禽生产者素质;加大政府对水禽产业的支持力度。     

软化指数对混凝土断裂过程区尺度的影响

应用Muskhelishvil应力函数全场解,根据幂指数函数描述的混凝土拉应变软化模型导出断裂过程区（FPZ）过程值及临界值的解析表达式,分析了在最大拉应变强度理论下软化指数对FPZ过程值及临界值的影响。结果表明:混凝土FPZ过程值及临界值都随着软化指数的增加而增加,不同泊松比下变化规律相近。     

支出弹性、消费升级与消费不平等

探究消费升级与消费不平等问题对于促进共同富裕具有重要意义。基于CHIP 2013年和CHIP 2018年数据,结合近乎理想需求系统(AIDS)模型等实证考察了我国居民消费升级与消费不平等状况。研究发现,样本期间中等收入及以下群体的消费处于升级状态;消费不平等呈现下降趋势,且主要源于高弹性商品消费不平等的下降。G·Fields分解结果表明,持久性收入差距是影响消费不平等的最主要因素,且对高弹性商品支出不平等和城镇地区消费不平等的贡献更大,暂时性收入差距对消费不平等的贡献度也相对较高;城乡差距、教育差距和家庭规模差异对于消费不平等同样具有较大的解释力度。因此,缩小城乡发展差距、教育差距和提高居民收入水平对降低消费不平等具有重要作用。     

An optimal credit policy to increase supplier's profits with price-dependent demand functions

This paper deals with the problem of determining an optimal length of credit period from the perspective of supplier. We assume that a retailer jointly determines the unit retail price and order size to maximize profit when he/she purchases a product for which the supplier offers a trade credit. Two widely used demand functions are adopted for the study in which demands are decreasing functions of the retail price. A procedure is presented which shows how to achieve an optimal length of credit period for suppliers. The effects of credit period on the behaviour of retailers are also investigated using an example.     

乡镇企业吸纳农村劳动力就业力度下降的原因分析——基于面板数据的实证研究

促进农村劳动力的就地转移就业是新型城镇化建设的重中之重,能够吸纳农村劳动力就地转移就业的主要载体就是乡镇企业。但是,当前一个不争的事实就是乡镇企业对农村劳动力的吸纳力度不断下降。主要原因有:乡镇企业资本对劳动力的替代并不是很强,乡镇企业没有足够的增长来吸纳劳动力,大多数省份的乡镇企业技术进步偏向仍然是劳动偏向型。国家应继续保持甚至加强对劳动密集型乡镇企业的政策扶持以及创造条件形成乡镇企业的规模经济和集聚效应,从而吸纳更多的农村劳动力通过进入乡镇企业实现就地转移就业。     

The Bias in Price Elasticity Estimates Under Homothetic Separability: Implications for Analysis of Peak-Load Electricity Pricing

This article demonstrates that the assumption of a homothetically separable utility function places a priori restrictions on the parameters of the demand system. If these restrictions are unwarranted, an open question if they are not explicitly tested, they will lead to biased price elasticity estimates. In particular, we show that the uncompensated own-price elasticities must be smaller than the negative of the expenditure shares; that is, the price elasticity of peak electricity demand must be less than the negative of the share of expenditure devoted to peak electricity. This finding is probably not new to economists familiar with consumer demand analysis. Nevertheless, many recent studies of consumer demand for electricity under time-of-day rates explicitly impose this restriction. The resulting price elasticity estimates are usually quite large in absolute value (.5 to .8); but they are the product of restrictive a priori assumptions as well as information embodied in the sample data. The results of two analyses of time-of-day experiments, where the researchers imposed the untested assumption of homothetic separability, are examined more closely. We find that the reported price elasticities are strongly influenced by that a priori assumption. A Monte Carlo experiment demonstrates that using this model will lead to the reported price elasticities even if the consumption data are perfectly random with respect to price.