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121.
武进区花卉苗木基地产业生态化建设方案研究   总被引:3,自引:0,他引:3  
苏南地区的快速城市化在带动地方经济大发展的同时,却给农村环境造成了巨大的压力,如何实现农村环境与经济协调发展是亟待研究的任务。江苏省常州市武进区花卉苗木基地的实践表明,对区域做出科学的生态经济区划,在严格保护基本农田的基础上,充分利用其它类型的土地资源因地制宜地发展花卉苗木生态产业,成为农村生态环境建设的优化途径之一。武进花木基地环境建设包括:(1)优化生态经济区划,将整个基地划分为平原水网和漏湖圩田两个生态经济区;(2)根据各生态经济区的不同特点采取相应的生态产业布局和实施方案;(3)发展具有“水乡、花卉、休闲”特色的生态旅游产业。  相似文献   
122.
A Profile and Management of the US Army's underground storage tanks   总被引:1,自引:0,他引:1  
The US Army owns more than 10,000 underground storage tanks (USTs), many of which are old and may be leaking. The Resource Conservation and Recovery Act of 1976 required tank owners to collect and report data on them by May 1986. In order to manage the large amounts of information on its USTs, the Army developed a microcomputer-based data base system. The data base system is user friendly and allows the user to store, organize, and manipulate the UST data. A leak potential index (LPI) was also developed and calculated for each of the Army's USTs. The LPI is used to prioritize USTs so that those with higher LPIs can be monitored closely. A characteristic profile of Army USTs according to construction material, capacity, age, content, and LPI is presented in this paper.The opinions expressed in this paper are those of the authors and do not necessarily reflect the views of the US Department of the Army, nor does the mention of trade names or commercial products constitute endorsement or recommendation for use.  相似文献   
123.
Aquatic acidification by deposition of airborne pollutants emerged as an environmental issue in southeastern Canada during the 1970s. Drawing information from the extensive research and monitoring programs, a sequence of issue assessments demonstrated the necessity of reducing the anthropogenic emissions of acidifying pollutants, particularly sulphur dioxide (SO2). The 1991 Canada-U.S. Air Quality Agreement (AQA) was negotiated to reduce North American SO2 emissions by 40% relative to 1980 levels by 2010, and at present, both countries have reduced emissions beyond their AQA commitment. In response to reduced SO2 emissions, atmospheric deposition of sulphate (SO4 2–) and SO4 2– concentrations in many lakes have declined, particularly in south-central Ontario and southern Québec. Sulphate deposition still exceeds aquatic critical loads throughout southeastern Canada however. Increasing pH or alkalinity (commonly deemed recovery) has been observed in only some lakes. Several biogeochemical factors have intervened to modify the lake chemistry response to reduced SO4 2– input, notably release of stored SO4 2– from wetlands following periods of drought and reduction in the export of base cations from terrestrial soils. Three examples from Ontario are presented to illustrate these responses. Significant increases in pH and alkalinity have been observed in many lakes in the Sudbury area of Ontario due to the large reductions in local SO2 emissions; early-stage biological recovery is evident in these lakes. An integrated assessment model predicts that AQA emission reductions will not be sufficient to promote widespread chemical or biological recovery of Canadian lakes. Monitoring and modeling are mutually supporting assessment activities and both must continue.  相似文献   
124.
城市火灾案例库辅助决策方法的研究   总被引:6,自引:1,他引:5  
在对城市火灾事故案例进行全面调查、统计和分类分析的基础上,提出一种城市火灾案例特征属性的表示框架,对特征属性进行了层次化和结构化,同时对属性值的取值进行较为科学而严格的定义,进而应用混合相似度度量方法和粗糙-模糊集方法提炼案例中蕴涵的灭火救援知识,给出一种灭火救援辅助决策过程模型;通过查找最相似案例和案例库提炼出相关的灭火救援规则进行灭火救援辅助决策;成功进行了实例验证。该模型的建立可为城市火灾案例智能决策系统的研究提供参考。  相似文献   
125.
寿王坟铜矿通风阻力测定与安全性分析   总被引:1,自引:0,他引:1  
矿井通风阻力测定是通风技术管理工作的重要内容之一,掌握矿井通风系统阻力的分布情况对矿井通风日常安全管理十分重要。本文介绍了几种通风阻力的测定方法,根据寿王坟铜矿的实际情况选用基点法对其进行了通风阻力测定,计算通风阻力测定数据并运用最小二乘法进行平差处理,使校正后的结果满足克希荷夫第一、第二平衡定律,为今后进行通风系统改造,提供了有参考价值的基础数据资料。最后依据测定结果对寿王坟铜矿通风系统安全性进行了分析。  相似文献   
126.
阐述了排污申报登记与环境监理的关系。指出,排污申报的作用 应当体现在对污染源监理的全过程中,应对申报数据进行核查,形成一个有效的污染源动态管理系统,并建立相应的污染源动态信息库。  相似文献   
127.
为充分发挥前兆数字化数据在地震预报中的作用 ,研制了基于SQL网络数据库的通用接口程序。该程序通过ODBC数据源直接从网上对数据库进行存取 ,并通过数据导出和日期格式的转换而形成前兆分析人员所需的数据格式。  相似文献   
128.
Abstract: The subjective nature of graphical base‐flow separation combined with the many applications of base‐flow time series derived from continuous streamflow data, motivates the development and application of automated algorithms for heuristic base‐flow separation. Base‐flow time series derived from gauged streamflow support diverse applications in engineering hydrology, catchment analysis, hydrogeologic investigations, regional low‐flow analysis, and recharge estimation. Whether based on graphical procedures for recession analysis or analytical expressions derived from fundamental equations of ground‐water flow, the variety of base‐flow separation algorithms belies the array of base‐flow definitions and interpretations that variously refer to dominant process, source, flow path, and characteristic response time. Algorithms that are invariant in their consistent – though heuristic – characterization of base‐flow response are particularly useful for interbasin comparisons of low‐flow characteristics and hydrologic regionalization. More adaptable algorithms provide application‐specific flexibility in allocating flow components like interflow to either quickflow or slowflow. Four widely used algorithms that produce consistent base‐flow time series using only gauged streamflow records are compared and contrasted with a complementary heuristic algorithm that incorporates hydrologic judgment explicitly, through manual parameterization. The utility of these inherently subjective algorithms is illustrated through a simple example of flow phase separation in a two‐component end‐member mixing model of dissolved chlorides in the Cuyahoga River.  相似文献   
129.
通过对昌吉州三工镇和榆树沟镇、米泉市古牧地镇和柏杨河乡种植区土壤、空气质量、灌溉水的监测分析与调查研究,对比清洁区蔬菜基地与污灌区蔬菜基地环境现状,探讨了灌溉用水对蔬菜质量的影响,提出切实可行的防治措施.  相似文献   
130.
Growing interest in green products has provided fresh impetus to the research in the field of renewable materials. Plant fibers are not only renewable but also light in weight and low in cost. Polymer composites manufactured using them find applications in diverse fields such as automobiles, housing, and furniture. However, their hydrophilic nature and inadequate adhesion with matrix limits their use in high performance applications. In this study, a novel method for improving adhesion characteristics of natural fibers has been developed. This method is carried out by treating hemp fibers with a fungus: Ophiostoma ulmi, obtained from elm tree infected with Dutch elm disease. Treated fibers showed improved acid–base characteristics and resistance to moisture. Improved acid–base interactions between fiber and resin are expected to improve the interfacial adhesion, whereas improved moisture resistance would benefit the durability of the composites. Finally, composites were prepared using untreated/treated fibers and unsaturated polyester resin. Composites with treated fibers showed slightly better mechanical properties, which is most probably due to improved interfacial adhesion.  相似文献   
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