农村金融发展对农村经济和农民收入的影响研究——基于VEC模型的实证分析

本文基于2001—2009年的季度数据,通过构建一个向量误差修正模型,实证分析了中国农村金融发展对农村经济增长以及农民收入增加的影响。结论表明,中国农村金融发展对农民收入增加产生了显著的影响,同时中国农村金融发展、农村经济增长以及农民收入增加之间存在长期的均衡关系。     

中国城镇化水平和就业结构关系的协整分析

本文利用协整理论、误差修整模型和Granger因果检验理论,对中国三次产业就业比重与城镇化水平之间关系进行了对比分析,结果表明二者之间是长期均衡关系;城镇化水平的提高促进了第一、二产业就业结构的调整;第三产业就业规模的快速发展促进了城镇化建设。     

World market integration for export and food crops in developing countries: a case study for Mali and Nicaragua

Using a generalized error correction model, this article measures and compares market integration for export cash crops versus imported food crops for Mali and Nicaragua, and computes transmission elasticities between changes in the goods’ border and domestic prices. Both Mali and Nicaragua obtain the bulk of their export revenue from a particular agricultural commodity—cotton for Mali and coffee for Nicaragua—and both import the same key staple food of rice. To reap the economic gains from this trade specialization, the two countries’ agriculture must be well‐integrated into world markets. The two countries present an important policy contrast that affects their degree of world market integration and price transmission. In Mali, a parastatal enterprise controls its cotton industry, while Nicaragua has less state direction over agriculture. Reflecting this difference, the results show that for both its main export and import commodity, Nicaragua is more integrated into world markets and has higher price transmission than Mali. The results for Nicaragua also show much higher integration and price transmission for its main agricultural export (coffee) than its major import (rice).     

FDI、国际贸易及我国经济增长的协整分析与VECM模型

本文利用我国1983-2004年的经济数据进行实证检验,根据协整理论建立向量误差修正模型(VECM)。实证结果说明外国直接投资、国际贸易与经济增长间具有长期均衡关系,且我国国内生产总值的增长与外国直接投资有双向因果关系,但相互影响的程度不同;我国为出口导向型经济增长国家且外国直接投资对国际贸易具有促进作用.     

大垂直口径天线俯仰波束赋形设计

给出了一种大垂直口径天线俯仰波束的优化设计过程。大垂直口径天线由10个辐射阵元 构成,可以看成为一个阵列。为使天线的辐射波束达到给定的波束要求,提出了一种改进 的遗传算法及其目标函数模型,对各辐射阵元的馈电幅度和相位同时进行优化。计算结果显 示,天线能够产生满足设计要求的俯仰波束。通过全波电磁仿真软件HFSS进行了验证,仿真 结果与计算结果吻合,证明了所提方法的有效性和实用性。     

Price relationships between qualitatively differentiated agricultural products: organic and conventional wheat in Germany

Organic agriculture, which produces commodities that can be qualitatively differentiated from conventional food products, has grown into an important market in many countries. The dynamics of commodity prices in both sectors are partly interdependent, but are also shaped by independent determinants and have rarely been studied. We analyze organic food markets and their interdependencies with conventional markets in the context of wheat markets in Germany, which have been subject to a number of fundamental changes during the last two decades. Based on institutional market characteristics, we suggest a flexible Markov‐switching asymmetric time series model. We find a pronounced temporal sequence of market phases that differ in their asymmetric dynamics and the extent to which the organic price is influenced by the conventional price. Organic wheat prices tend to be increasingly connected to prices of conventional wheat.     

基于耕地质量分等更新成果的基本农田划定——以江苏省高邮市周山镇为例

划定基本农田对保障粮食安全有重要意义,而合理评价耕地综合质量是基本农田划定的重要前提与基础。以江苏省高邮市周山镇为例,基于耕地质量分等更新成果,从区位条件、便利条件和空间形态条件三方面构建了修正因素体系,并采用加权修正法测算了耕地的综合质量指数,最终根据上级政府给周山镇下达的基本农田保护面积,按综合质量指数的高低确定了入选基本农田的耕地。研究结果表明:周山镇耕地修正后的综合质量指数范围为2562-2735,指数≥2613的耕地入选基本农田,其面积为31.34 hm2;入选基本农田的耕地空间分布范围与现状相比更能满足国家对基本农田划定的要求。     

农村居民旅游消费影响因素研究

在考察旅游需求经济理论的基础上,选择1994-2008年的年度数据为样本,利用协整分析与误差修正模型实证分析了农村居民旅游消费的决定因素。结果表明,农村居民旅游消费不仅受自身收入、消费习惯等因素的制约,而且受城镇居民旅游消费的影响。农村居民旅游消费收入弹性大,人均可支配收入仍是其旅游消费的最大制约因素;农村居民旅游消费有显著的不可逆性,＂棘轮效应＂明显;城镇居民旅游消费行为对农村居民有显著的＂示范效应＂。此外,农村居民居住消费对旅游消费有＂挤出效应＂。因此,在继续重视增加农民收入、拉动旅游消费的同时,可通过培养其良好的消费习惯、建立城镇居民旅游消费的正面示范机制,发展农村旅游休闲消费。     

财政支出与产业结构的关系研究——基于协整分析和误差修正模型

通过运用单位根检验、协整检验、格兰杰因果检验及误差修正模型等经济计量分析方法,分析了1978—2009年中国财政支出和产业结构系数之间的关系,得出结论：财政支出和产业结构系数之间存在长期均衡关系和单向的因果关系;误差修正项对财政支出与产业结构系数之间的长期均衡具有调节作用,但这种调节力度比较弱。     

薜荔在室内光照适应范围的研究

研究了薜荔的绿叶(Ficus pumila)及花叶(Ficus pumila'Sunny White')品种的室内光照适应范围问题;根据室内光的分布,选择房间内具有代表性的光区进行栽培试验;在16～28℃,RH30%～64%条件下;经栽培82天后,用LI-6400测定其不同光强下的光合特性,计算光补偿点、光饱和点、最大净光合速率,并测定不同试验区枝条长度的生长量;结果表明,在该条件下,绿叶品种生长的适宜光照为7.8～527.0μmol/m2.s(392～26350 lx),薜荔花叶品种为6.9～491.0μmol/m2.s(347～24550 lx)。