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301.
管道式气体、粉尘爆炸实验装置设计尺寸的确定   总被引:1,自引:0,他引:1  
就管道式可燃气体爆炸DDT的转换进行了理论研究,初步探讨了管道式实验装置设计尺寸选择的理论依据.  相似文献   
302.
城市化的快速推进,在城市建成区边缘和资源禀赋条件较好的农村地区产生了大量半城市化地区。在城市化、工业化等多重影响下,半城市化地区经历着从单一农村社会向城乡多元社会的转变。以姜堰市城郊结合部为例,分析半城市化对农村地区社会和空间变化的影响。结果表明:半城市化地区就业结构和居民家庭收入来源的非农化水平不断提高,农业在就业结构和家庭收入来源中的重要性逐渐下降;空间结构和功能呈现出更多的城市特征,居住空间正在由传统的自然村落向城市社区过渡。同时,半城市化地区存在着土地利用混杂低效、基础设施和公共设施服务匮乏、原住居民就业和社保形势严峻等亟待破解的问题。最后,针对姜堰市城郊结合部现状提出建议,推进城市化的健康发展  相似文献   
303.
以Mn(Ⅱ)与Pd(Ⅱ)为催化剂的吸收净化溶液对黄磷尾气中的PH3进行了液相催化氧化研究。考察了混合气中02浓度、温度、入口PH3浓度、气体流量和吸收液pH变化与磷化氢净化效率曲线的关系。实验结果表明:混合气中较佳的氧含量为5%;在20℃至75℃范围内,低温对催化净化有利,较适宜的反应温度为20℃;较低的PH3入口浓度和低气速均有利于对PH3的净化;吸收液较高的pH有利于吸收液中催化剂催化效能的发挥。吸收液对PH3的净化效率可达100%,但因吸收液中的金属离子易与PH3产生的PO4^3-形成沉淀,使金属离子脱离液相催化氧化系统,吸收液失效较快。  相似文献   
304.
Climate targets call for novel policy measures to facilitate widespread adoption of low-carbon solutions and innovations. The literature on socio-technical systems argues that experimentation has a prominent role in enabling sustainability transition. Experiments represent ways of testing new ideas and methods across a wide range of policy fields. Governance experiments in particular can support accelerated diffusion of new solutions, because they integrate policy with innovations. Here, types of success factors in the implementation of governance experiments to mitigate climate change are examined. Statistical analysis of sustainability innovations in the 28 European Union countries indicates that the types of success factors in governance experiments differ from those of product and social experiments. Governance experimentation is more positioned within socio-technical regimes than in strategic niches. These results suggest that governance experiments may indeed provide new transition opportunities towards low-carbon societies.  相似文献   
305.
A series of heterogeneous KF/CaO catalysts modified with transition metals (lanthanum, cerium, and zirconium) were prepared via wet impregnation method and applied to the trsansesterification process of waste cooking oil (WCO) as feedstock with methanol to biodiesel production. The structure, performance of the solid catalysts was characterized by X-ray diffraction (XRD), temperature programmed desorption of CO2 (CO2-TPD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The effect of methanol/oil molar ratio, 1reaction time, reaction temperature, catalyst amount, and stability was investigated. The results showed that 10 wt% of lanthanum, cerium, and zirconium improved the catalytic activity of KF/CaO catalyst. The maximum catalytic activity using the lanthanum doping of 10wt% on KF/CaO catalyst was reached 98.7% under the optimal reaction condition of methanol/oil molar ratio of 12:1, reaction for 1 h at reaction temperature of 65°C, and 4% (wt/wt oil) catalyst amount. In addition, the FAME yield of KF/CaO/La catalyst remained higher than 95% after 10 cycles. The promotional effect of lanthanum doping could be attributed to the enhancement of the basicity strength of KF/CaO catalyst and block the leach of Ca2+ in the transesterification reaction.  相似文献   
306.
Studies of advanced capitalist societies have shown that relatively wealthy localities with organized environmental groups are able to avoid unattractive facilities. The aim of this article is to ask whether the same logic applies in Hungary, a middle-income ‘transition’ society. The focus is not on the formal legal powers of local governments but on some of the influences on local government environmental policy. Drawing on a survey of mayors, notaries and environmental officials in 600 local government units in Hungary (from Budapest to villages), it explores the relation between environmental group mobilization, environmental group influence and environmental policy. It is shown that there are systematic differences in environmental group mobilization between settlements of different types, and that these differences, together with differences in local economic situation, explain the differing levels of perceived influence of environmental groups on policy. The localities where perceived environmental group influence is greatest are identified and shown to be places where there are higher education institutions and a tradition of ‘civic culture’, or where the local government is using the environment as an asset as part of an economic development strategy. It is concluded that similar processes to those found in advanced capitalist societies exist in Hungary. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
307.
Along with the rapid growth of economy in the postreform period after 1979,China has faced severe problems of resource overusing and environmental degradation which would threaten the sustainable development of economy and society.This article explores an effective mechanism of managing resource and environment in China.It examines some major resource and environmental issues,and constructs a framework of institution innovation to cover three sectors(government,market and society).In addition,the article analyzes their experience and evaluation in resource management and environmental conservation during the transitional period.We argue that the combination of market regulation,government intervention and public participation is an effective way of allocating resource and protecting environment.Some suggestions are put forward to balance the relationship between them,including coordinating role of government and market,building platform for market operation and creating an atmosphere of public participation.  相似文献   
308.
兴化市小城镇土地集约利用综合评价研究   总被引:3,自引:0,他引:3  
小城镇是我国城镇体系的重要组成部分,促进小城镇土地集约利用不仅是缓解当前小城镇发展中存在问题的关键举措,也是推动小城镇健康发展的重要途径。在借鉴城市土地集约利用研究的基础上,分析了小城镇土地集约利用的内涵,构建了小城镇土地集约利用综合评价指标体系,并基于因子分析法分析了江苏省兴化市小城镇土地集约利用水平及其影响因素。结果表明:兴化市城镇土地集约利用水平分为高水平、较高水平、中等水平、低水平和不集约5类,从市域范围看城镇土地集约利用水平整体上从南向北递减,分别形成以戴南镇、昭阳镇和戴窑镇为中心向外围递减的空间格局;进一步分析土地集约利用影响因素基础上,根据各因素对城镇土地集约利用的制约程度,将小城镇划分为土地利用效益制约型、土地利用程度制约型、城镇基础设施制约型和城镇土地可持续利用制约型4种类型,并据此提出针对性的对策措施.  相似文献   
309.
Now environment is an important topic in academic field. Many researches focus on the negative outcomes of nature which are being continually created by human and much attention has been paid to how the environment is protected through integrated research, movement and policy. But few studies are concentrated on population and environment and are to find out the interconnectivity and underlying mechanism that have an effect on people's preferring additional children and perception to environment. Many researchers claim that population growth is a great problem for environment but they do not provide the indepth integrated knowledge and mechanism that influence fertility trend and environmental problems. It is very crucial to develop practical and concrete initiatives to confirm a transition to reduce population growth and redirect the perception on population and environment.  相似文献   
310.
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