国内外不同尺度的旱灾风险评价研究进展

作为旱灾风险管理实践的科学基础,旱灾风险评价愈来愈受到社会各界的广泛关注。在阅读大量文献的基础上,从4个不同的区域尺度对国内外旱灾风险评价研究进展作了综述。结果表明:(1)目前所有区域尺度研究中,农业旱灾风险评价研究较多;(2)地区尺度的旱灾风险评价是研究其他尺度的切入点,可为实现空间尺度上推(全球和国家尺度)和下推(县乡农户尺度)旱灾风险评价结果的转换提供依据;(3)随空间尺度从全球和大洲→国家→地区→地方尺度,旱灾风险评价的文献量逐渐增多,内容逐渐深入;(4)旱灾风险对饥荒和粮食安全的影响、农业系统和农作物承灾体的旱灾风险评价是目前研究的热点。在此基础上,指出旱灾发生频率较低但生态环境敏感区的旱灾风险评价需加强;从干旱灾害链的角度以及综合旱灾风险与脆弱性、恢复性、适应性的关系来研究旱灾风险是今后的重点。     

Emissions trading of global and local pollutants, pollution havens and free riding

In the presence of local (sulfur) and global (carbon) pollutants, we examine the pollution haven hypothesis and free riding behavior. Under domestic emissions trading, poorer Southern countries become pollution havens when free trade opens up whenever sulfur damage functions are linear or when sulfur levels in equilibrium are not higher in the South. With global trading of carbon permits, the pollution haven effect emerges in equilibrium whenever the convex sulfur damage functions are nonlinear. Countries that do not participate in a Global Protocol designed to reduce carbon emissions enjoy double benefits, stemming from free riding and cleaner local environments.     

Large eddy simulation of plume dispersion behind an aircraft in the take-off phase

The aim of this paper is to provide an investigation, using large eddy simulation, into plume dispersion behind an aircraft in co-flowing take-off conditions. Validation studies of the computational model were presented by Aloysius and Wrobel (Environ Model Softw 24:929–937, 2009) and a study of the flow and dispersion properties of a double-engine aircraft jet was presented by Aloysius et al. (EEC/SEE/2007/001, EUROCONTROL Experimental Centre, ), in which only the engine was modelled. In this paper, the complete geometry of a Boeing 737 is modelled and investigated. The current work represents a contribution towards a better understanding of the source dynamics behind an airplane jet engine during the take-off and landing phases. The information provided from these simulations will be useful for future improvements of existing dispersion models.     

发展地方环保产业的思考

本文论述了发展地方环保产业的六大要素：优势、科技、龙头、基地、环境、创新。抓住了这六大要素,地方环保产业就可成为地方经济新的增长点。     

Co-Partnership in Forest Management: The Gwira-Banso Joint Forest Management Project in Ghana

The involvement of local communities, as well as the private sector and the government in forest management is now an important principle of tropical forestry policy and practice and a major component of most international forestry aid programmes. This paper present an analysis on the Joint Forest Management Project initiated by two timber companies (Ghana Primewood Products Ltd and Dalhoff Larsen & Horneman) in collaboration with local people in Gwira-Banso of Ghana. Conditions required for enhancing responsibility for and commitment to local forest management, and for an effective local participatory process were also analysed. The study began with the premise that incentives and good communication will enhance participation in joint forest management.The assumption was valid and the results from the survey showed that five broad issues prioritised by respondents to be essential for co-partnership in forest management are communication, financial support, tree planting, multiple land use and benefit sharing. The Project enjoys a great deal of support from the local community, but a number of factors make the continued support of local people a challenging task, including questions of immediate livelihood sources and tenure arrangements. Although this participatory forest management has been implemented over a relatively short period, there is evidence that government and private sectors can successfully involve local people in sustainable management of the forests.     

生态恢复过程中的种群遗传学考虑

生态恢复是生态科学的最终实验,从种群角度看,恢复的目标是使种群（尤其是优势种或建群种）到具有生长、繁殖和适应进化变化的能力。要达到这个目标,种群遗传学知识必不可少。遗传变异是物种适应变化环境的基础,而局部适应则是种群适应局部环境遗传分化的结果,它们在生态恢复中起着重要的作用。分析了生态恢复过程中影响种群遗传变异因素,主要有取样误差和小种群效应（主要是瓶颈或建立者事件及其以后的近交和漂变等）,在进行     

厌氧-局部循环供氧生物膜技术处理农村污水

通过模拟农村生活污水水质和间歇进水特点,利用“厌氧-局部循环供氧生物膜”技术,研究该工艺对有机物、氮、磷的去除效果.厌氧池和局部循环供氧池有效容积比为1∶1.6,曝气装置位于局部循环供氧池中间底部,环形导流板将局部循环供氧池分隔成中间好氧区和四周缺氧区,斜管沉淀池前置到厌氧池与局部循环供氧池之间,出水端设置循环水池.装置连续稳定运行12个月,平均进水量为140 L/d,生物反应区HRT为1.3d.监测结果表明,出水COD、BOD、NH3-N、TN和TP平均浓度分别在40.31、3.38、2.69、11.98和0.75 mg/L,达到了国家城镇污水处理厂污染物排放指标(GB-18918-2002)中的一级排放标准.研究表明,厌氧-局部循环供氧技术是一种适合农村分散污水处理的新工艺,可有效减轻农业面源污染.     

高速冲击下多胞材料细观结构中波传播规律

目的 获取安全防护结构中细观多胞材料在高速冲击下的波传播规律.方法 采用基于3D-Voronoi细观多胞结构数值仿真和基于最小二乘法的局部应变梯度法,研究细观多胞结构在高速冲击下的冲击波波阵面传播规律.通过细观多胞结构数值仿真提取的位移场数据,结合局部应变梯度法得到界面清晰的冲击波波阵面.结果 冲击端和支撑端分别诱发右...     

ECONOMIC EFFECTS OF RIVER RECREATION ON LOCAL ECONOMIES1

ABSTRACT: Outdoor recreation is a major, growing use of water resources in the United States. The economic effects of expenditures by visitors to three recreational river sites on local economies surrounding the sites were estimated using an input-output model (IMPL.AN). Expenditure data were from the Public Area Recreation Visitors Study (PARVS). Results indicate that visitor spending stimulates a considerable amount of economic activity and growth in local economies. Economic effects include increases in total gross output ranging from $2.6 million to $13.4 million, increases in total income ranging from $1.2 million to $5.6 million, and increases in employment ranging from 60 to 292 jobs.     

高温高含二氧化碳条件下五种含Cr钢适用性评价

目的 预测某高温高含二氧化碳油井中管柱的腐蚀情况,为该油井推荐安全经济的材质。方法 采用高温高压反应釜模拟现场工况进行腐蚀试验,通过失重法、扫描电子显微镜(SEM)和X射线能谱分析(EDS)对五种含Cr钢的适用性进行评价。结果 在40~160 ℃温度范围内,五种钢材随温度的升高,其均匀腐蚀速率先升高后降低,且均在80 ℃时达到最大值。3Cr钢的腐蚀速率最高,在整个温度范围内,均远高于0.076 mm/a。在温度为120 ℃时,9Cr钢开始出现局部腐蚀。在温度为160 ℃时,13Cr钢有一定的局部腐蚀倾向。S13Cr、22Cr钢在整个温度范围内的腐蚀速率都较低,试验后试样表面平整连续,耐蚀性能好。结论 建议在采出井井筒中上部40~80 ℃较低温度井段选用9Cr钢,中部80~120 ℃中高温井段选用13Cr钢,底部120~160 ℃高温井段选用S13Cr钢。