The Impact of NAFTA on Mexico's Environmental Policy

A major controversy during the debate over the North American Free Trade Agreement focused on the impact of NAFTA on Mexico's environment. This paper examines the evidence of impact specifically on Mexico's environmental policy. Criteria of impact are developed, and comparisons made for three periods: before 1990 as the baseline period; 1990-93 when NAFTA was being negotiated; and beginning in 1994 when NAFTA came into effect. Much evidence indicates that Mexico's environmental policymaking and enforcement did improve in the early 1990s while NAFTA was being debated. Some evidence also suggests that the NAFTA-influenced environmental commitment was sustained during the 1995 financial crisis. Thus, it is concluded that NAFTA has contributed significantly to Mexico's environmental policy.     

环境质量影响指数法在商丘市土地整治规划环境影响综合评价中的应用

为了解决土地整治规划环境质量影响综合评价定量化的难题,探索简便易行的土地整治规划环境质量影响综合评价技术方法,以土地整治规划实施前后土地利用结构的变化为切入点,以规划实施对环境系统结构-功能-价值的影响为分析评价对象,构建了环境质量影响综合评价指标体系,建立了环境质量综合影响指数法定量评价模型,应用该方法对商丘市的土地整治规划进行了环境影响综合定量评价。评价结果表明,评价指标易于定量化取值,综合影响指数法评价模型简便易行,规划方案实施对环境质量综合指数的影响值为+11.76,规划实施对区域环境质量的影响总体是有利的,规划方案具有环境可行性。以规划实施对环境系统结构-功能-价值的影响为切入点,构建的环境质量影响评价指标体系针对性强、评价指标易于量化;环境质量影响综合评价模型法使评价工作得以大幅简化,实用性强,具有推广应用价值。     

The Impact of the Maquiladora Industry on U.S. Border Cities

For decades, the maquiladora industry has been a major economic engine along the U.S.–Mexico border. Since the 1970s, researchers have analyzed how the maquiladora industry affects cities along both sides of the border. Hanson produced the first comprehensive study on the impact of the maquiladoras on U.S. border cities, considering the effects of in‐bond plants on both employment and wages. His estimates became useful rules of thumb for the entire U.S.–Mexico border; however, they have become dated. Using Hanson's framework, we estimate the maquiladora industry impact on U.S. border cities from 1990 to 2006. We find that a 10 percent increase in maquiladora production leads to a 0.5 to 0.9 percent increase in employment. We also find large differences among individual border cities. Furthermore, we estimate the cross‐border maquiladora impacts before and after 2001 when border security begins to rise, and the global low‐wage competition intensified after China joined the World Trade Organization. Empirical results indicate that U.S. border cities are less responsive to growth in maquiladora production from 2001 to 2006 than in the earlier period; however, when looking into specific sectors, we find that U.S. border city employment in service sectors is more responsive post‐2001.     

基于环境因子的春玉米产量结构模型分析研究

环境因子对作物产量的影响是现代农业气象研究的重要内容之一,建立春玉米产量结构模型可为春玉米的科学生产提供依据.本研究分析贵港春玉米不同生育阶段的环境因子与产量结构的相关性,并建立全因子、显著因子的多元线性回归模型和BP神经网络模型.结果表明,对春玉米产量结构影响最大的生育期为拔节—抽雄期,10～40 cm的土壤水分体积...     

WTO对中国种业的影响

我国是一个农业大国,但非农业强国,在农业中种业市场有很大的发展空间,有很大的容量.然而我国种业发展水平低,基础设施薄弱,管理与发达国家有很大的差距.面对入世后各种经济发展环境,种业将面临严峻考验.     

种植业结构调整空间辅助决策系统研究

研究者建立种植业结构调整空间辅助决策系统主要是为了使县域种植业经济效益达到最大化，使县域农作物种植结构最优化，能够为决策者提供决策的依据；在决策系统的研究中，研究者针对研究区域的特点建立了辅助决策模型，采用GIS中MapObjects控件与辅助决策模型内嵌式集成的方法，应用VB编程语言，形成面向种植业结构调整的空间辅助决策系统；决策者在种植业结构调整空间决策系统中可以对农作物种植数据进行动态查询，查询数据还可以直观动态地显示在相应的地图位置。在后台数据库的支持下，决策者可以计算每年各个乡镇各种农作物的适宜性参数，决策系统可以自动将农作物适宜性参数输入模型中参与计算农作物的种植面积，决策者可以根据不同情况选择决策系统中的不同模型进行计算农作物种植的调整数据。根据往年的农作物种植面积与计算所得的种植面积进行比较，得到农作物需要调整的种植面积。系统可以根据调整前后的农作物种植面积进行效益分析，利润分析，生成图表，能够直观动态地为决策提供支持。以河北正定县为例对所开发的种植业结构调整决策系统进行实例验证，结果表明，该系统设计合理可行，能够为县域的种植业结构调整提供决策支持，具有一定的实践价值和意义。     

环境污染转移对中国农村可持续发展的影响

为了建设中国特色社会主义新农村,实现农村的可持续发展,环境污染向农村转移的问题就必须高度重视。笔者主要分析了环境污染转移对中国农村的生态环境及农民身体健康造成的严重影响,结果导致贫困,并指出环境污染转移导致了恶性循环,同时提出了相应的对策建议。最后得出的结论是污染企业要走循环经济之路,中国农村未来的发展方向是发展生态农业。     

消费需求变化视角下的产业结构优化

为了促进经济的快速发展,保证产业结构与需求结构的协调发展。通过分析消费结构变化对产业结构的影响,研究了中国消费需求结构的变化,并结合中国渔业产业结构的现状,借鉴日本在渔业产业结构优化方面的经验,提出了优化中国渔业产业结构的对策建议。     

Impact of Characteristic Culture on the Optimization of Rural Tourism Industry

Based on current rural tourism development of China and its typical modes,this paper on the basis of studying significance and impact of characteristic culture on rural tourism proposes the concept ofintegrating characteristic culture and rural tourism,elaborates significance of attractive force of folk cultures,expressive power of vernacular cultures,appeal of characteristic cultures for the optimization of rural tourism industry.     

环境因子对长白山区天然核桃楸林生长的影响

以长白山区14块核桃楸为主具有代表性的林分样地为研究对象,分析核桃楸的生长指标与14个环境因子的相关性,以期揭示环境因子对核桃楸生长的影响。结果表明：（1）不同林分组成的核桃楸林对核桃楸的生长影响显著,其中含落叶松的核桃楸林中径生长优于其他林分的核桃楸,而且郁闭度对树高影响显著(R=0.5049)。（2）坡向和坡位分别与胸径、材积(P＜0.05)和树高、胸径、材积(P＜0.01)呈显著和极显著相关,而坡度与其材积呈显著负相关(R=-0.5016)。（3）海拔与胸径和材积呈显著正相关(R=0.4918、R=0.5203),经度与材积呈显著负相关(R=-0.5428)。（4）土壤厚度和土壤碱解氮含量对其树高的影响均显著,作用大小为：土壤碱解氮含量＞土壤厚度;土壤中有机质含量和土壤pH值对其胸径的影响均显著,作用大小为：土壤中有机质含量＞土壤pH值;土壤中碱解氮含量与材积呈极显著正相关(R=0.8314)。     

武汉市垃圾填埋场选址评价模型研究

为实现垃圾卫生填埋处置对环境影响最小化，填埋场场址的合理选择至关重要的一步。笔者在专家调查的基础上，利用层次分析法(AHP)，建立了以城市规划要求、交通运输条件、与城市的距离、环境保护条件、地质环境条件、建场条件为一级指标的垃圾填埋场选址评价模型，为武汉市的垃圾填埋场选址提供科学依据。     

The Impact of Metropolitan Structure on Commute Behavior in the Netherlands: A Multilevel Approach

ABSTRACT This paper documents the investigation of the impact of metropolitan structure on the commute behavior of urban residents in the Netherlands. Not only has the impact of monocentrism versus polycentrism been analyzed, but the influence of metropolitan density and size has also been considered, together with the ratio of employment to population and the growth of the population and employment. Furthermore, data are used at a variety of levels of analysis ranging from the individual worker to the metropolitan region rather than being drawn from aggregate level statistics alone. Multilevel regression modeling is applied to take account of the interdependencies among these levels of aggregation. With regard to mode choice, the results indicate that the probability of driving an auto to work is lower in employment‐rich metropolitan regions, and rises as the number of jobs per resident has grown strongly. Furthermore, women in most polycentric regions are less likely to commute as an auto driver. All else being equal, commute distances and times for auto drivers are longer in most polycentric regions than in monocentric urban areas. In addition, commute time as an auto driver rises with metropolitan size, whereas commute distance depends on employment density and the growth of the number of jobs per resident. The investigation shows that metropolitan structure, although significantly influencing commute patterns, explains only a small part of the variation of individuals’ commute behavior.     

Legal Ponder over the Agent of Environmental Impact Assessment

The Environmental Impact Assessment Law of our country stipulated that the project and construction items should be assessed using the method of environmental impact. The planning office becomes the agent of environmental impact assessment is as important as the agent of project construction for the first time. The scope, duty, and the legal responsibility of the agent, which does the assessment using the method of environmental impact, should be standardized and perfected. It will be helpful to implement the work of environmental assessment and make it legal.     

The Impact of Geographical Proximity on Vertical Integration through Specific Assets: The Case of the Spanish Meat Industry

The aim of this paper is to evaluate the role that agglomeration may have on vertical boundaries in exchanges associated with high transaction costs. Transaction cost economics identifies the presence of specific assets in stages of the value chain as the main driver of vertical integration. However, under the trustworthy and shared social milieu that agglomerated spaces may confer, neighboring firms can enjoy lower opportunism risk and communication costs. Therefore, we assume that even in the presence of specific assets, physically proximate firms are more likely to remain specialized and establish market exchanges. Empirical evidence in 10,186 establishments from the Spanish meat industry confirms these hypotheses, although it is found that the moderating role of agglomeration in the relationship between asset specificity and vertical integration has a limited geographical reach.     

农业结构调整对粮食安全的影响及其规避途径

本文根据广西农业结构调整和粮食生产现状,探讨了在新形势下农业结构调整对粮食安全的影响,提出了以提高思想认识为先导、以加强主产区建设为重点、以推进结构调整为主线、以推动产业化经营为手段、以加快科技进步为依托、以加大政策支持为保障等规避粮食安全隐患的有效途径。     

3种转非抗虫基因棉花田间节肢动物群落的多样性和食物网结构

以转基因耐盐碱棉花、转基因抗病棉花和转基因抗旱棉花3种转非抗虫基因棉花为材料,研究不同表达性状的转基因棉花种植对棉田节肢动物群落结构、多样性及食物网结构的影响。结果表明,3种转基因棉花在节肢动物群落Shannon-Wiener多样性指数、Pielou均匀度和优势集中性指数上与其对照受体棉花无显著差异(P0.05)。转基因棉花与其对应受体间的群落相似性指数均较高(73.18%~77.65%),食物网结构参数上也无显著性差异(P0.05)。表明3种转非抗虫基因棉花对棉田节肢动物多样性及食物网结构无显著影响。     

Analysis of the Impact of Ownership Structure on the External Corporate Governance

Taking-over market, the main component of external corporate governance, affects the performance of corporate governance significantly. Through taking-over activities between companies, the market assumes its role in the governance mechanism. This paper analyzes the taking-over market of listed company in China from the view of ownership structure. By looking into the indirect taking-over activities between companies, the authors research the impact of specific ownership structure on the effectiveness of external corporate governance deriving from such activities. It is concluded that innovation of ownership structure is the key for taking-over market to take its role in external corporate governance more effectively.     

中国农业政策环境影响初步分析

国家农业政策是国家总体经济政策的重要组成部分,是政府为了实现一定的农业、经济和社会发展目的。对影响农业发展的重要环节所采取的一系列具有宏观调控作用的政策措施的总称。国家农业政策的实施,可能会对中国的环境及其保护事业造成巨大的压力和影响。通过对中国农业政策背景、政策目标、政策利益相关者、政策手段等进行分析总结,指出中国农业政策通过改变农户生产结构、生产方式和生产技术等对农业环境产生影响。目前对农业环境影响较大的农业政策有粮食安全政策、土地政策、提高农民非农收入的政策、结构调整政策和农业环境政策。通过对这些政策对农业环境的影响分析,提出了要提高对农业环境问题的重视程度、实施农业政策与环境政策一体化,深化农地使用制度改革、明确界定土地所有权主体、稳定土地承包关系,制定激励政策减轻农业面源污染,建立健全农业环境污染监管机制,重视生态建设,发展生态农业等政策调整建议。     

环境变化对新疆霍尔果斯气候资料的影响

为方便资料用户准确地把握霍尔果斯站的气候资料信息,进而揭示真实的气候变化特征与规律,选取霍城和伊宁县作为参考站,利用霍尔果斯站和参考站1961—2014年的同期观测资料序列进行了完整性、区域一致性和均一性分析。发现,霍尔果斯站观测资料完整性好,但气温、降水、湿度和风速共4个要素的区域一致性均较差,并且均存在不连续点。同期对比观测资料分析结果表明,相对湿度、降水量和风速一致性较好,气温和风向一致性比较差。显著性检验结果表明,新址和旧址除年、月平均风速差异显著,不能连续使用外,其他5个要素基本通过了显著性检验,资料可以连续使用。而风速在资料服务中需要进行订正,方可连续使用。