湖南产业集群化发展模式研究

产业集群作为某一产业领域关联的企业及其支持系统在一定地域内集聚并形成具有持续竞争优势的经济群落,已经成为当代世界经济发展的一大趋势。湖南作为中部地区的一个重要组成部分,要实现在“中部地区崛起”中的快速发展,就必须形成一批在全国有强大竞争优势的产业集群。通过对产业群发展现状与特征阐述,分析了湖南现有的四大产业群发展模式及其特征,指出了产业群发展中存在的主要缺陷和不足,并提出了相应的发展对策和措施。     

QuEChERS结合液相色谱-串联质谱联用法同时测定植物源性食品中多种双酰胺类农药残留

利用QuEChERS技术结合液相色谱-串联质谱联用法建立同时测定植物源性食品中6种双酰胺类农药残留的方法。样品采用乙腈作为提取剂,在缓冲盐环境下经振荡提取,C18、PSA和GCB净化,样液过膜后经C18柱分离,在电喷雾离子源、正离子扫描模式下多反应监测方式检测,基质配标,外标法定量。6种双酰胺类农药残留在0.1~150.0μg·L^-1浓度范围内线性良好,相关系数大于0.995;加标回收率为64.3%~106.0%,相对标准偏差为1.6%~9.7%,检出限为0.1~1.0μg·kg^-1。该方法简便、准确、灵敏,是同时测定植物源性食品中6种双酰胺类农药残留的有效方法。     

完善我国公司治理和财务治理模式的思考

随着国有企业改革的深化,人们越来越认识到公司治理和财务治理模式不完善是国有企业存在的深层次矛盾,是阻碍国有企业改革的关键所在,因此必须尽快完善我国国有企业公司治理和财务治理模式,才能使其适应市场的变化和竞争的要求。     

苯醚甲环唑在猕猴桃中的残留动态及安全性评价

为摸清猕猴桃中有毒有害物质的残留动态,确保出口产品质量安全符合主要贸易国官方要求,本文采用气相色谱-质谱法,测定施药后不同时期苯醚甲环唑在猕猴桃果实中的残留量,并依据残留消解动态,按照欧盟和日本食品安全卫生标准,对10%苯醚甲环唑水分散粒剂的使用安全性进行评价。结果表明,苯醚甲环唑在猕猴桃中的残留量随着时间的推移逐渐下降,动态曲线符合一级动力学方程C_t=0.5359e^(-0.184t),半衰期为3.767 d,属易消解农药;按照欧盟和日本猕猴桃农药最大残留限量要求,10%苯醚甲环唑水分散粒剂按照推荐剂量单次施药,10天后采摘食用是安全的。     

农户风险感知与施药行为的响应关系研究——基于辽宁省菜农数据的实证检验

本文基于辽宁省蔬菜主产区434户菜农调研数据,运用结构方程模型验证了农户风险感知与施药行为的响应关系。研究结果表明,农户风险感知潜变量正向影响农户的施药行为响应,但是风险感知和施药行为潜变量中各个因子的影响路径和显著程度存在差异;农户是否加入合作社对农户风险感知与施药行为的作用关系起到一定的调节效应。基于研究结论,本文提出风险意识提升、保障条件供给和发展新型农业经营主体三方面的建议。     

我国农药使用现状、原因及对策研究

我国农药使用状况十分不堪,对农村生态环境及广大农民的身体健康造成严重影响,究其根源,农药管理体系不健全,生物农药发展滞后及农民的低物质文化水平是主要原因;要解决此问题,必须从这3方面着手,逐步完善农药管理体系,大力发展生物农药,积极促进农村经济和教育的发展。     

Ecosystem impacts of pesticide reductions through Bt cotton adoption

This article examines the ecosystem impacts of transgenic Bt cotton technology resulting from reduced chemical pesticide use. Employing unique panel data from smallholder farmers in India, negative environmental and health effects of pesticide use are quantified with the environmental impact quotient (EIQ), with and without Bt technology. An environmentally sensitive dynamic production function is estimated, treating the environmental risk of pesticide toxicity as an undesirable output in the production process. Negative externalities are significantly lower in Bt than in conventional cotton. The reduction in EIQ through Bt technology adoption has increased from 39 per cent during 2002–2004 to 68 per cent during 2006–2008. Bt adoption has also contributed to higher environmental efficiency. Environmental efficiency is influenced by the quality of Bt technology: high‐quality Bt seeds are associated with higher environmental efficiency than lower‐quality seeds.     

Neighbourhood Effects in Pesticide Use: Evidence from the Rural Philippines

This study investigates how pesticide use by neighbouring farmers affects a given farmer's pesticide use. Although it is common knowledge that pesticide use has spatial externalities, few empirical economic studies explicitly analyse this issue. Applying a spatial panel econometric model to plot‐level panel data for Bohol, Philippines, this study shows that pesticide use, especially for herbicides, is spatially correlated, although there is no statistically significant spatial correlation in unobserved shocks. This implies that farmers apply pesticides by referring to the behaviour of neighbouring farmers rather than responding directly to the intensity of their own infestation.     

A Meta‐Analysis on the Elasticity of Demand for Pesticides

There is an increasing policy interest in pesticide taxation schemes as a measure to reduce harmful effects of pesticide use. The effectiveness of such tax depends, however, on the price elasticity of demand for pesticides. Moreover, information on these demand elasticities and their determinants is of crucial relevance for policy‐making and normative modeling approaches. In this article, we present a meta‐analysis based on studies that have estimated pesticide demand elasticities in Europe and North America. Our meta‐analysis reveals that the own‐price elasticities of demand for pesticides are, with a median of ?0.28, significantly smaller than zero, but also significantly larger than ?1, i.e. to be inelastic. We find that the demand for pesticides for special crops is less elastic than that for arable and grassland. In addition, the demand for herbicides is more elastic than for other pesticides. Studies that consider only short‐term horizons and little flexibility for farmers to adjust to price changes generate significantly less elastic pesticide demands. The results also indicate that more recent studies identify lower pesticide price elasticities of demand. Furthermore, we find that peer‐reviewed studies tend to find more inelastic results compared to grey literature.     

利用钢结构建筑残值证券化实现钢铁资源储备

在地球资源枯竭之前,为了国家在未来的国际资源争夺战中占领制高点,应未雨绸缪对资源实现大规模的战略储备。当前,利用我国建筑业高速发展机遇期,大规模推广钢结构建筑以求较大规模钢铁集中消耗形成＂藏钢于屋＂即可实现钢铁资源的战略储备,这样一种储备不会影响钢铁资源在建筑中使用价值的发挥,从而规避了＂冬眠＂式储备。钢结构建筑成本高是制约其发展的瓶颈,根据钢结构建筑中钢材易集中回收以及残值较高的特点,文章提出了钢结构建筑残值证券化的新概念。采用钢结构建筑残值证券化手段,可以让证券持有人在分享因资源枯竭或通货膨胀带来的丰厚收益的同时分担高昂的建造成本,从而能够使国家以超低成本或零成本实现大规模钢铁资源战略储备。