The Impact of Public Expenditure and International Trade on Agricultural Productivity in China

The “industry nurturing agriculture” reforms and World Trade Organization accession led to dramatic growth in public expenditure and international trade in China’s agricultural sector. This article aims to estimate the effects of public expenditure and trade on agricultural productivity in China for 2004–2015. A semi-parametric production function with shape constraints is introduced to derive more accurate productivity before the productivity determinants are analyzed with an emphasis on public expenditure and trade. The empirical result shows that public expenditure and exports can effectively improve agricultural productivity, while imports have no significant effects. Policy implications are discussed in the context of supply-side reforms.     

各向异性厚板固有频率的精确解

该文抛弃薄板理论的位移和应力假设，利用矩阵分析和三维弹性动力学理论，导出四边简支各向异性厚板的固有频率方程。该方法可推广应用于各向异性层合板动力分析。     

用弦线模量法计算地基沉降和黄土湿陷变形

用弦线模量法^[1]设计黄土地基，从计算地基沉降和湿陷变形出发，概念清楚，方法简单，用地基的物理指标得出弦线模量，可省去做压缩实验。     

财政补贴改革刍论

财政补贴是国家宏观调控的杠杆之一,但是,目前补贴不规范,财政补贴数额大、项目繁杂,补贴效果‘异化’,加大了社会不公。为了强化财政补贴杠杆功能,提高财政补贴效益,必须按照建立公共财政的要求,本着满足公共需要原则、弹性补贴制度原则和补贴方式间接化原则,改变“一刀切”和补贴刚性的局面,确保采暖费收支合理化,取消肉食、副食品、粮食等价格补贴,改革国有企业的亏损补贴制度。     

砼偏心受压构件折减系数计算公式的几个注解

根据弹性稳定理论,对当量弯矩折减系数Cm的计算公式的应用范围作了进一步说明,并确定了其应用范围.同时,考虑砼偏心受压构件的弹塑性性能,推导了新的公式,与原有的公式比较,具有同样的精确度,由于考虑了砼材料的变形模量,因此其结果更接近实际.     

南京商圈构造及其对策

工业化、城市化、信息化和市场化的互动推动了都市圈的形成。都市圈的形成可以带来分工与资源重组效应、要素的聚集与扩散效应、分享效应以及新型的竞争与合作效应等。在南京都市圈逐步形成的基础上,南京商圈也已初步出现。在南京商圈的进一步发展中,我们应该明确:城市商业结构的总体结构应是商业专业化的形态结构、布局结构、业态结构和技术结构动态组合的过程,南京及周边城市地区要互动调整自己的商业布局、业态与技术结构,选择适合于自身的竞争战略,形成互相竞争与合作的新型区域关系。     

数字经济对我国碳排放的影响研究

基于2013-2020年的30个省份数据构建面板数据模型,从碳排放总量和碳排放强度两个视角研究数字经济发展对区域碳排放的影响。研究发现：数字经济的发展有效地降低了人均碳排放量、碳排放增量与碳排放增速,数字经济与碳排放强度之间存在倒“U”形关系,数字经济与碳排放强度、边际碳排放强度的关系呈现区域性特征,在省域层面数字经济对边际碳排放强度的影响不存在明显的空间效应,数字经济对碳排放增长率的影响存在基于产业结构优化、人口集聚、城镇化的遮掩效应。     

Anticipated Environmental Policy and Transitional Dynamics in an Endogenous Growth Model

This paper makes a new attempt toinvestigate how an anticipatedenvironmental policy governs the transitionaldynamics of an economy when pollutionexternality is taken into account. Themodeling strategy we use is an AK technologyendogenous growth framework with an endogenousleisure-labor choice. It is found that, unlikeinelastic labor supply framework, a rise inpublic abatement expenditure will stimulate thebalanced economic growth rate. It is alsofound that public abatement technology plays animportant role in determining the transitionaladjustment of the economic growth rate inresponse to a pre-announced environmentalpolicy.     

基底冲刷对桥墩安全性影响研究

文章研究了冲刷造成桥墩倾覆和其他所有可能的破坏,针对湖南资水大桥实例,对可能的冲刷破坏进行了分析和研究,用数值积分法计算了基底冲刷对基础检算各项目的影响,包括冲刷对倾覆稳定性、墩顶弹性水平位移和基底压应力的影响3个基本部分,最终得出基底冲刷对桥墩安全性的影响。     

N‐FIRM OLIGOPOLY WITH GENERAL ISO‐ELASTIC DEMAND

In this note oligopoly with iso‐elastic demand is analysed. Unlike previous studies we consider general iso‐elastic demand rather than the case of unit elasticity. An n‐firm Nash‐Cournot equilibrium for the case of heterogeneous constant marginal costs is derived. The main result is a closed‐form solution that shows the dependency of the equilibrium on the elasticity of demand and the share of industry costs. The result has applications to a wide range of areas in oligopoly theory by allowing comparisons across markets with different elasticities of demand.