火灾下圆钢管约束钢筋混凝土短柱轴压性能分析

利用ABAQUS软件建立了火灾下圆钢管约束钢筋混凝土轴压短柱非线性有限元模型,在确定混凝土和钢材的本构基础上,对其火灾下轴压性能进行了数值计算,并与已有相关试验数据进行了对比验证。分析了环境温度、混凝土强度、钢管屈服强度、截面尺寸、含钢率等参数对火灾下轴压性能的影响规律。结果表明:火灾下各试件核心混凝土纵向应力发展规律较为相似,且应力分布趋向均匀;环境温度对试件轴压刚度的影响大于极限承载力,材料强度对极限承载力的影响较大,增大钢管含钢率可一定程度提高试件轴压刚度;提出了火灾下此类试件极限承载力和轴压刚度的简化计算公式,可为工程实际应用提供参考。     

九黄环线旅游可持续发展现状研究

通过对九黄环线旅游业在可持续发展道路上面临的积极因素及不利因素的分析，探讨了九黄环线旅游业可持续发展现状。以可持续发展理念为指导，提出了九黄环线旅游可持续发展目标，以及进一步做好环线线路规划建设、加大可持续发展宣传力度、加强旅游管理、增强族游可持续环境保护等具体措施，进一步明确了九黄环线旅游业可持续发展的建设方向。     

The effect of wind direction on ozone levels: a case study

This paper provides an illustrative case study on how the wind direction plays an important role in determining the ozone levels, in a suburb of Houston. Circular correlation and circular regression methods are used in the analysis and the primary goal is to illustrate how circular data analytic methods help in analyzing certain environmental issues. Received: August 2003/Revised: June 2004     

Optimization of animal manure vermicomposting based on biomass production of earthworms and higher plants

The goal of this study was to optimize the mixture of swine manure (SM) and cattle manure (CM) used in the vermicomposting process, seeking to increase the manure biodegradation rate and enhance the biomass production of both earthworms and higher plants. To achieve this goal, physico-chemical parameters were determined to assess the final compost quality after 50 days of vermicomposting. The different manure ratios used to produce the composts (C) were as follows (SM:CM, % m/m basis): C1 100:0, C2 (75:25), C3 (50:50), C4 (25:75), and C5 (0:100). In addition, the earthworm biomass and the phytoproductivity of lettuce (Lactuca sativa L.) plants grown in mixtures (1:1) of natural soil and the most viable vermicomposts were investigated. The C1 and C2 compost compositions were associated with high earthworm mortality rates. The C3 compost provided the highest mineral concentrations and C5 showed the highest lettuce yield (wet biomass). The results verify that stabilized cattle manure is an excellent substrate for the vermicomposting process and that fresh swine manure must be mixed with pre-stabilized cattle manure to ensure an optimized vermicomposting process, which must be controlled in terms of temperature and ammonia levels. It is concluded that small livestock farmers could add value to swine manure by applying the vermicomposting process, without the need for high investments and with a minimal requirement for management of the biodegradation process. These are important technical aspects to be considered when circular economy principles are applied to small farms.     

煤炭产业物质流核算的指标体系构建研究

循环经济落实到实处,不仅需要从技术端不断推进新技术在生产活动各领域的应用,更需要一个整体的资源和能源管理体系.物质流核算即是通过对国家、地区或产业的实物流的核算,理清资源和能源使用过程.通过针对循环经济发展较为成熟的煤炭产业进行物质流核算的指标体系构建,找到一些建立物质流核算体系的思路,并提出具体政策建议.     

川化股份有限公司循环经济竞争力评估研究

循环经济建设是从根本上缓解资源环境短缺与经济快速发展之间的尖锐矛盾的有效模式。本文对四川省发展循环经济建设成效较显著的试点企业——川化股份有限公司进行基于循环经济的企业竞争力评估。通过建立企业循环经济竞争力评估指标体系,采用数学模糊评估模型,系统分析了企业的基于循环经济的竞争力水平。报告的评估成果显示,经5年的企业循环经济建设,截止2009年,川化股份有限公司基于循环经济的企业竞争力总体处于“强”的水平。     

企业实施循环经济的战略探讨

本文从循环经济的原则出发,根据国际实践以及中国实行循环经济的实际情况,提出了企业实现循环经济发展的四种战略：清洁生产和全过程污染控制战略、企业生产者责任延伸战略、产业链拓展战略和废弃物综合利用战略,为企业进行循环经济建设提供一定的指导和参考作用。     

基于三层结构的绿色招商选择体系研究

阐述了中国招商引资的基本情况及存在的问题,提出了进行绿色招商的必要性.在绿色招商选择系统结构分析的基础上,提出了基于三层结构的绿色招商选择体系,并根据该体系构建了s工业园的绿色招商选择体系.     

大力推广中水技术促进循环经济和可持续发展

通过对循环经济和可持续化发展，及我国目前正面临着严重的水资源危机的介绍，阐述了采用中水技术，实现污水的资源化，不但可以降低污染，减少污水排放费用，而且是实现循环经济和可持续发展的有效途径，有着很大的社会效益和经济效益。     

生态学原理在生态工业园发展中的应用

近年来生态学原理越来越广泛的应用于人类社会的各个方面,尤其是随着循环经济模式的提出和清洁生产理念的倡导,生态工业园成为工业园发展的未来方向。本文重点阐述了国内外生态工业园的类型以和发展趋势,以及我国生态工业园目前在建设过程中存在的相关问题。