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91.
双二元经济是我国生态建设补偿机制面临的根本约束条件。首先简要回顾了我国双二元经济的形成逻辑同环境污染现状之间的内在联系。指出我国政府在建国初期所采取的赶超战略和改革开放后的地区不平衡发展战略是联系二者的历史渊源。在此基础上构建的博弈模型表明。在双二元经济结构的约束条件下。生态建设供给的博弈均衡应是由东部发达地区和城市先进部门承担绝大部分甚至是全部的生态建设成本。因此。我国生态建设补偿机制的构建方向就应该是构建一个有效完善的跨区域、跨部门的生态建设补偿机制。以平衡生态建设者和生态建设收益者之间的成本和收益,这是保障生态建设可持续发展的关键。  相似文献   
92.
作物产量差及其形成原因综述   总被引:4,自引:0,他引:4  
范兰  吕昌河  陈朝 《自然资源学报》2011,26(12):2155-2166
作物产量差是现实产量与潜在产量的差距。产量差研究意在揭示作物产量差的幅度与地域差异、形成原因以及缩小产量差的措施。产量差意味着农业发展的机会,因此,分析和研究产量差对提高作物产量、保障粮食安全意义重大。论文通过文献综述,首先讨论了产量差的定义,在此基础上,总结了世界和我国主要作物的产量差,分析了产量差的影响因素与缩小产量差的措施。最后讨论了目前产量差研究中存在的问题与不足,提出了产量差应重点关注的问题。  相似文献   
93.
A recent turn towards a more contextually sensitive apprehension of the challenge of making everyday life less resource hungry has been partly underwritten by widespread evidence that the environmental values people commonly profess to hold do not often translate into correspondingly low impact actions. Yet sometimes the contexts of everyday life can also conspire to make people limit their consumption without ever explicitly connecting this to the environmental agenda. This paper considers this phenomenon with reference to UK studies from both ends of the generational spectrum. The first questioned how older people keep warm at home during winter and the second examined how young people get rid of no longer wanted possessions. Both found that, though the respondents involved were acting in certain ways that may be deemed comparatively low impact, they were hitherto relatively indifferent to the idea of characterising these actions as such. We outline three ways in which sustainability advocates might respond to the existence of such “inadvertent environmentalists” and consider how they might inspire studies that generate fresh intervention ideas instead of lingering on the dispiriting recognition that people do not often feel able to act for the environment.  相似文献   
94.
The RE-AIM framework, created by Russell Glasgow and colleagues, addresses five major factors involved with sustained population-level effectiveness of public health interventions—Reach, Efficacy and/or Effectiveness, Adoption, Implementation and Maintenance. In this article, I illustrate how the framework might be applied to environmental communication interventions, and discuss how the framework needs to be adapted to important aspects of this context. Following that, I address several potential criticisms of RE-AIM or its usefulness for environmental communication scholars. Finally, I discuss how research practices of environmental communication scholars could be changed in light of the insights given by the RE-AIM framework. Much work remains to be done in order to see exactly how RE-AIM, or other frameworks focused on large-scale intervention effectiveness, can be made most useful to environmental communication scholars. However, RE-AIM already provides a valuable way to start thinking about how to best improve large-scale effectiveness of communication interventions.  相似文献   
95.
基于各地区环保投资供给能力和环保投资需求,从供给能力和需求用途2个方面对2006—2010年我国31个省市自治区的环保投资历史欠账进行匡算。研究发现,北京等7个省市自治区的环保投资实际供给始终高于供给能力,其他地区的环保投资均存在一定的供给缺口,即环保投资历史欠账。从需求角度看,基础设施建设投资需求被充分满足,工业污染源治理投资需求与供给基本一致,建设项目“三同时”环保投资供给远不足以满足投资需求,欠账问题严重。另外,环保投资欠账较为严重的地区集中在东北、中部和西北3个区域,京津冀经济圈、长三角和珠三角的环保投资欠账相对较少。  相似文献   
96.
为降低现有除尘器的改造成本,提高微细粉尘的收集效率,在现有除尘器的基础上,对阳极板排布方式进行调整,设计错位排布方式,最大化地利用原有除尘器的资源,以最小的改造成本,达到较满意的除尘效果。利用目前应用广泛的FLUENT仿真软件进行数值模拟,观察分析了其电势分布和气流分布。数值模拟结果表明:当主流风速小于0.5 m·s−1时,离子风对流场的影响较大;当主流风速达到0.8 m·s−1以上,主流风成为影响空间流场分布的主要因素,离子风的影响被削弱,但此时的离子风团仍会促进气流流入错位极板背部达到收集目的。错位板间隙设计可以削弱离子风对阳极板的冲刷作用,证明了错位板排布有利于改善离子风对粉尘收集的负面影响,有效提高对微细粉尘的收集效率。数值模拟的结果对静电除尘器的设计与改进有一定的参考意义。  相似文献   
97.
98.
The Maximum Experimental Safe Gap (MESG) is an important criterion to assess the propagation of flames through small gaps. This safety-related parameter is used to classify the flammable gases and vapors in explosion groups, which are fundamental to constructional explosion protection. It is used both, for the safe design of flameproof encapsulated devices as well as for selecting flame arresters appropriate to the individual application. The MESG of a fuel is determined experimentally according to the standard ISO/IEC 80079-20-1:2017 at normal conditions (20 °C, 1.0 bar) with air as oxidizing gas. The aim of this work is to investigate the effect of inert gas addition on the MESG in order to assess the effectiveness of inertization in constructional explosion protection. The term limiting experimental safe gap (SG) is used for the result of these measurements. The fuel-air mixtures (fuels: hydrogen, ethylene, propene, methane) used as representatives for the explosion groups in flame arrester testing were chosen and diluted with inert gas (nitrogen, carbon dioxide) before testing. The dependence of the limiting experimental safe gap on the total initial pressure, amount and nature of inert additive is discussed. The initial pressure was varied up to 2.0 bar to include increased pressure conditions used in flame arrester testing. Apart from the well-known reciprocal dependence on the initial pressure, the added inert gas results in an exponential increase of SG. This effect depends on the inertizing potential of the gas and is therefore different with nitrogen and carbon dioxide. The ranking of the fuels is the same as with MESG. As a result, various mixtures of the same limiting experimental safe gap can now be chosen and tested with an individual flame arrester to prove the concept of a constant and device-related limiting safe gap. The work was funded by BG-RCI in Heidelberg (PTB grant number 37056).  相似文献   
99.
为了正确评估新型杀虫剂环氧虫啶(CYC)的环境风险,了解环氧虫啶在水环境中的光降解规律,探讨了CYC初始浓度、温度、初始pH值、过氧化氢浓度及硝酸根对CYC光降解的影响.结果表明,CYC的光降解符合一级动力学反应.直接光降解中,随浓度降低、温度升高,光解速率加快,环氧虫啶的反应活化能为21.27kJ/mol.通过测定CYC的pKa值为3.42以及模拟计算CYC不同粒子形式的光反应活性,可知pH值对CYC光解的影响较为复杂:酸性条件下,CYC的降解速率取决于其形态(阳离子和中性粒子)与单线态能量;碱性条件下,降解速率主要受羟基自由基数量的影响.间接光降解中,硝酸根和过氧化氢对CYC光解均表现为促进作用.在评估环氧虫啶的环境风险时,应综合考虑环境因素对其降解的影响.  相似文献   
100.
Abstract: Conservation assessment is a rapidly evolving discipline whose stated goal is the design of networks of protected areas that represent and ensure the persistence of nature (i.e., species, habitats, and environmental processes) by separating priority areas from the activities that degrade or destroy them. Nevertheless, despite a burgeoning scientific literature that ever refines these techniques for allocating conservation resources, it is widely believed that conservation assessments are rarely translated into actions that actually conserve nature. We reviewed the conservation assessment literature in peer‐reviewed journals and conducted survey questionnaires of the authors of these studies. Two‐thirds of conservation assessments published in the peer‐reviewed scientific literature do not deliver conservation action, primarily because most researchers never plan for implementation. This research–implementation gap between conservation science and real‐world action is a genuine phenomenon and is a specific example of the “knowing–doing gap” that is widely recognized in management science. Given the woefully inadequate resources allocated for conservation, our findings raise questions over the utility of conservation assessment science, as currently practiced, to provide useful, pragmatic solutions to conservation planning problems. A reevaluation of the conceptual and operational basis of conservation planning research is urgently required. We recommend the following actions for beginning a process for bridging the research–implementation gap in conservation planning: (1) acknowledge the research–implementation gap is real, (2) source research questions from practitioners, (3) situate research within a broader conservation planning model, (4) expand the social dimension of conservation assessments, (5) support conservation plans with transdisciplinary social learning institutions, (6) reward academics for societal engagement and implementation, and (7) train students in skills for “doing” conservation.  相似文献   
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