氮元素施用与农户粮食生产效率:来自全国农村固定观察点数据的证据

本文采用2003～2015年全国农村固定观察点的大样本数据,构建相关随机效应模型(Correlated Random Effect)尽可能降低传统随机前沿生产函数中一步法的内生性问题,实证分析氮元素施用对农户家庭层面"加总"粮食生产效率的影响。在清理数据的过程中,本文对全国农村固定观察点数据可能存在的面板数据衔接偏误问题进行纠正,进一步检验了计量分析结论的稳健性。研究结果表明,中国农户粮食生产过程中氮元素施用过量,对粮食生产效率具有显著的负向影响,且这一结论是稳健的。氮元素施用对粮食作物生产效率的负向影响存在着异质性,对不同经营规模农户的影响效果是显著的,但对不同区域农户的影响效果并不显著。基于实证研究结论,本文提出了适当降低氮元素施用量的政策建议,即为农户施肥提供技术指导,深入推进化肥减量化和有机肥替代行动,健全化肥相关管理条例与科学施用的指导办法。     

Excel函数在考勤统计中的应用

在日常的工作中,最让人头疼的可能就是关系到员工的工资收入的考勤工作,针对这个问题,摸索出一个用Excel管理考勤的方法,减少了工作量,降低了出错律.     

买结构性理财产品先看说明书

央行一纸降息令,激起投资市场千层浪,“宝宝”们蔫了,股市火了.于是,全民炒股时代来临,就连开个户也要排很久的队.那么,问题来了,不会炒股的人该怎么办?难道注定要与牛市擦肩而过?不妨试试银行结构性理财产品,挂钩股市的产品,分一杯牛市的羹.不过,结构性理财产品有些复杂难懂,想赚钱要先看清产品结构和收益条款.     

合作社农户入社偏好、违约风险与治理研究

通过建立农户加入合作社的入社偏好函数,并基于偏好函数对不同市场行情中农户的违约行为进行博弈分析。发现不同市场行情中,农户的违约倾向存在差异,且农户的违约行为不仅来源于农户的投机倾向,也与合作社提供的生产服务及市场定价能力密切相关。要规避农户违约行为,进而更好地促进合作社的发展,设计合理的农户与合作社双方约束和激励机制显得十分重要,只有合作社与农户的违约行为得到有效的约束,合作行为得到有效激励,才能使合作社更好的发展。在对农户违约行为动机分析的基础上,提出了能够较好的约束农户与合作社违约行为的双边约束机制及提高合作社经营绩效的激励机制,试图让合作社与农户间的违约行为得到矫正,合作社与农户的合作得到加强。     

带权Bernstein基的对偶泛函在时序相似性度量中的应用

提出了带权Bernstein基的对偶泛函的离散形式,并用于逼近时间序列,将基函数的控制向量作为时间序列的特征向量,达到压缩数据的目的。根据时间序列的凸包个数解决了对偶泛函的定阶问题,用时间序列的特征向量提出了基于极大似然比的相似性检验统计量,并给出相似系数的计算公式。最后通过正交变换得到相互无关的控制点特征向量,据此可以实现多个时间序列的相似性比较、聚类分析等。模拟数值试验证明,该方法能有效压缩数据,计算精度高,可实现不等长度的时间序列数据的相似性比较,体现了大数据挖掘的特点。     

中国城乡居民年龄别消费模式量化与分析

文章采用2010年中国家庭追踪调查(CFPS)数据量化分析年龄别居民消费模式。针对同类研究只采用年龄变量作为自变量的不足,在经典的需求和消费函数基础上扩展年龄变量构建计量模型,获得了更好的解释力和准确性。基于计量分析结果刻画了分年龄、性别的中国城乡居民消费模式,并进行城乡比较。研究发现,居民家庭消费生命周期中存在30~34岁及45~49岁两个消费高峰;城乡居民消费差距最大的是高龄老人;农村老人在高龄阶段的医疗保健消费明显下降;农村中年妇女的医疗保健支出低于男性。研究认为,应从政策层面有针对性地加大对特定年龄性别人群的扶助力度;同时,未来产业规划应充分考虑人口结构变动因素的影响。     

中国农业环境技术效率与污染减排成本分析

采用数据包络分析方法,利用方向性距离函数考察了2001-2010年期间中国农业环境技术效率,并评估了中国农业污染减排成本。研究发现,中国东部地区农业环境技术效率水平最高,西部次之,中部地区最低。在样本期间,各地区农业环境技术效率水平都有所提升,尤其是东部地区增长最快。中国农业污染减排成本巨大,严格的农业环境管制政策将造成94.52亿元的农业生产损失,占农业总产值的7.88%,且各地区减排成本在样本期内均呈增长趋势。此外,东部与中部地区减排成本高于西部地区,在三大地区内部,减排成本最高的均为农业大省。     

函数与方程思想方法在中考解题中的应用

函数与方程思想方法是中学数学的基本思想，几乎渗透到中学数学的各个领域，在解题中有着广泛的应用。函数思想与方程思想虽有着各自的概念与性质，但它们之间又密切相关。本文将对函数与方程思想的概念、如何相互转化以高效解题及其在中考中的应用加以详细阐述。     

工程质量政府监督多层次利益分配与激励协同机制探究

The implementation of the government supervision of the quality of the project is an international practice. The basic form of government supervision of engineering quality is government supervision on the quality behavior of the engineering main bodies and its results by the competent government department entrusted. Its essence is a dual principal-agent process. The frequent accidents of the engineering quality reflect the loss and failure of the government law enforcement supervision of the engineering quality to some extent. Its root lies in the lack of endogenous power in the law enforcement supervision of the project quality government supervisors in the law enforcement supervision. Therefore, the incentive coordination mechanism of the government supervision based on the multi-level interest distribution is worth explored. In views of the multi-level management system which is formed by the government departments, government quality supervision organizations, quality supervision team (or group) for the government supervision of engineering quality. The benefit distribution function between every party is constructed, and the game model of the multi-level incentive and coordination for the government supervision in engineering quality is built. To solve and deduce from the first stage of the cooperative game and the second stage of the non-cooperative game, the cooperative game can obtain the reward coefficient: . The coordination degree of the best effort can be obtained by the non cooperative game. The result shows that:the coordination degree of government engineering quality supervisor is related to the coordination costs, and had nothing to do with fixed costs. The benefit distribution coefficient not only depends on the efforts of the quality government monitors, but also on the efficiency of other parties' efforts. The quality supervisors of the project will also focus on the coordination with other parties when enhancing their management capabilities to improve the overall performance of project quality government supervision. The strategy of the incentive coordination mechanism for the supervision and cooperation of the project quality government is:the government quality supervision team should set up the supervisory team properly, improve the coordination efficiency and reduce the cost of supervision-coordination to maximize the value of self-motivation. Quality supervision team (or group) should establish the partnership to improve the coordination efficiency for achieving the maximization of their own incentive value.The model and conclusion of incentive synergy mechanism based on multi-level benefit allocation mechanism are researched. It can provide theoretical support and practice reference for the market governance and supervision of general public goods.