"民工潮"与"民工荒"--农民工劳动供给行为视角的经济学分析

当今中国农民工不再是一个高度同质的群体,而是已经在内部产生了分化.本文主要通过对第一代农民工和第二代农民工的特征及其劳动力供给的经济学分析,揭示世纪之交前后我国出现“民工潮”和“民工荒”的微观层面的原因,认为第二代农民工是最需要市民化也是最容易市民化的群体,但同时需要相应的制度创新和政策安排.     

1978~2014年间中国玉米生产的时空特征变化研究

［目的］厘清中国玉米生产的时空变化特征,有助于保障玉米的持续、稳定供应。［方法］文章采用经验模态分解等方法,基于玉米总产、播种面积及单产3个指标,从全国和省域两个尺度系统分析1978~2014年中国玉米生产的时空特征。［结果］（1）研究期间,全国玉米产量增加了1.60亿t,其波动量呈现先增大后减小的趋势,波动指数的变化幅度不大; 玉米播种面积增加了1716万hm2,其变化趋势与玉米总产量的变化趋势基本一致;玉米单产从1978年的2802.7kg/hm2波动性增至2014年的5809.1kg/hm2,总体波动幅度大于玉米播种面积和总产量的波动幅度。（2）研究期间,省域玉米增加量呈现出“北高南低”的特征,中国玉米生产重心进一步北移;省域玉米播种面积增加量呈现出“北高南低”“西高东低”的特征,东北区和华北区的玉米播种面积进一步扩大;省域玉米单产增加量呈现出“西高东低”“北高南低”的特征,省域单产以趋势增长为主,但年际间的波动较剧烈。［结论］1978~2014年,省域间玉米生产分异特征明显,建议制定差别化的玉米生产策略。     

当前影响我国粮食生产的主要因素分析

我国是世界上人口最多的国家,是粮食产量最大的国家,也是世界粮食贸易中的重要一员.自新中国成立以来.我国粮食产量及生产能力增长较快,虽然在1959～1961年和2000～2003年间粮食产量出现了较大幅度的下降,但整体上仍呈上升趋势.长远来看,粮食生产受资源、气候、技术、市场等因素的制约,并受种粮比较效益影响.产量大幅度增长的难度较大.当前影响我国粮食生产的主要因素是粮食播种面积和单产水平.由于人口增长、工业化和城镇化进程加快等,我国粮食总播种面积呈下降趋势,但随着科技进步加快和农业投入加大等因素的影响.我国粮食作物单产水平呈不断上升的态势.     

供应商质量管理

随着企业间的竞争不断加剧,很多企业逐渐把企业的非核心业务外包出去,产品生产已不再是由一家企业单独完成,而是由供应链上的各个成员企业共同协作完成,因此,供应商质量管理成为企业的一个重要课题。文章探讨了对供应商的选择及其动态管理的方法,以期达到提高企业质量管理水平,创造良好效益的目的。     

二外学习者使用学习策略情况的对比研究(英文)

本文研究了英语专业本科生和研究生在学习第二外语"日语"时所使用学习策略的差异。基于对调查问卷的分析,其各自特征如下:(1)在学习二外的过程中,英语专业研究生总体使用学习策略的频率略高于本科生;(2)针对各类学习策略,英语专业研究生的使用频率均高于本科生。作者提出了如何帮助本科生使用学习策略的建议。     

行动导向教学在高职“Linux系统管理”课程中的运用

在计算机网络技术专业＂Linux系统管理＂课程中应用行动导向教学,有利于丰富课程教学的形式和手段,为学生提供更加有效的学习方式,全面提高学生的综合职业能力。在课程教学实践中,运用行动导向教学,从课程的整体培养目标出发,对教学内容设计及实施、教学方法、教学考核形式进行改革。     

中国省域间居民收入水平收敛性实证检验

利用2000-2008年我国31个省级区域人均收入面板数据,应用多种面板单位根检验方法和不同比较基准对全国及东、中、西三大区域的城镇及农村居民人均收入是否存在收敛性进行实证检验。结果发现,以北京人均收入为基准,不管是全国还是三大区域,不管是城镇还是农村,都只存在条件收敛,不存在绝对收敛。而以全国人均收入为基准,在全国层面城镇和农村都既存在绝对收敛,也存在条件收敛。以组内平均水平为基准时,三个区域的城镇都存在对本组内平均水平的绝对收敛,农村情况基本相反,三个区域都不存在绝对收敛。东部和西部存在条件收敛,而中部不存在条件收敛。     

Sales management control level and competencies: Antecedents and consequences

The pursuit of superior salesperson performance and higher levels of sales organization effectiveness is a growing management priority. Management control is an important antecedent to several aspects of salesperson performance and organizational effectiveness. However, prior research has neglected two important issues. First, the impact of market orientation on sales manager control approaches has not been previously considered. Second, sales manager competencies in behavior-based control have not been examined, as research has focused on the level and form of control. Market orientation and the critical sales skills required of salespeople have strong antecedent relationships with sales manager control. Also, sales manager control competencies play a significant role in shaping salesperson performance, and the impact of control competencies is larger than control level. Sales manager control competencies play an important mediating role between sales manager control level and salesperson performance and sales organization effectiveness. Our findings are based on a study of British companies in which five hundred sales managers were sent surveys and 300 usable responses (a response rate of 60%) were returned. Three important implications derived from this study include: (1) sales managers need to translate market orientation into sales force behaviors; (2) control strategy should be aligned with sales force priorities; and (3) time and resources should be invested in training sales managers.     

Endogenous timing of actions under conflict between two types of second mover advantage

In this model, two players, who are heterogeneous in information quality, compete with each other with perfect information about the other player's information quality. The less-informed player has an incentive to delay her action in order to gain more information. The more-informed player also intends to delay her action, not through a desire to learn but rather to prevent the less-informed player from gaining information. Hence, if a waiting option is available, both players want to delay their actions and the conflict between the two types of second mover advantage yields a delay race. Although both players can benefit from a delay, the gain from a delay in order to learn is greater than that from a delay intended to prevent the other from learning. Therefore, the cost for a delay plays an important role in characterizing the equilibrium, and if the sequential timing of actions is derived in a pure equilibrium, the leader will be the more-informed player. If a given cost for a delay is sufficiently low, the only equilibrium is a mixed equilibrium. Interestingly, in that equilibrium, the existence of the first-mover advantage from being imitated is also derived.     

区分关键路径与非关键路径的项目进度偏差分析模型

挣值管理法是项目成本和进度控制中应用比较广泛的一种方法。文章分析了传统挣值进度偏差分析的缺点,提出了区分关键路径与非关键路径的进度偏差分析方法。分别探讨了关键路径和非关键路径的进度偏差。在各级施工单元计划编制的基础上,引入挣得时间ET（Earned Time）原理,建立整个项目的进度偏差分析模型。该方法可以精确地分析项目的进度偏差情况和偏差来源。