PE内衬技术在给水管网维修方面应用的探讨

诸多因素造成目前城市的给水管网 ,除了不断新建外还必须对原有管道进行更新、改造。但是更新改造原有管网异常棘手 ,我们通过市场开发与技术研究 ,认为PE内衬技术具有无可比拟的优越性 ,是解决这一问题的最佳途径     

怀洪新河浮游动物群落特征与水环境因子的关系研究

为研究怀洪新河太湖新银鱼国家级水产种质资源保护区(以下简称保护区)水域浮游动物的群落结构及其与水环境因子的关系,于2014年6月(夏季)在怀洪新河进行采样分析,并对调查区域内的浮游动物及主要环境因子进行了主成分分析(PCA)和典范对应分析(CCA)。结果表明,保护区河段属中营养型河流;保护区浮游动物有4门24属33种,其中轮虫类最多,为11种(占33.33%),其次为原生动物和桡足类,均为8种(占24.24%),最少的为枝角类6种(占18.18%);保护区浮游动物细胞密度平均为1.82×10~4ind./L,生物量平均为2.45mg/L;水温和氨氮是影响水体环境的关键因子;水温、总氮、浊度、氨氮、高锰酸盐指数(COD_(Mn))和pH是影响浮游动物群落结构的主要驱动因子。     

城市森林生态系统服务功能价值评估初探

城市森林为城市生态系统提供了多方面的服务功能。本文以大连市为例,对城市森林净化环境、涵养水源、固碳释氧、保护土壤等生态服务功能进行评估计算,并分析城市森林系统生态服务功能总价值的构成。     

基于VEGETATION数据的区域生态系统质量评价之二——生产能力指数评价

区域生态系统生产能力指数是评价其生态功能的重要指标之一.文章构建了区域生态系统生产能力指数评价模型,并对中国1998～2004年间区域生态系统生产能力进行评价,发现中国各区域生态系统的生产能力在时空发布上差异巨大,在空间上呈现从西北往东南逐级变好的趋势,西北最差.在时间分异上,区域生态系统生产能力呈现明显的季节性发布,尤以北方地区最为明显.     

生态系统评价的若干问题探讨

对生态系统的评价可分为两类，一是对生态经济状态的评价，二是对生态经济服务功能的评价，前者主要是在生态评价研究的初期，侧重于对生态系统所处的形势的评价；后者是在最近几年发展起来的，侧重于对生态系统所提供的产品和服务的价值评价，文章概述了方面评价的国内外研究进展，并在评价目的，评价尺度，评价参与者，评价的方法和技术手段等方面进行了探讨。     

Timber harvest calculations on a National Forest: A case study

Harvest calculations determine sawtimber flows from public lands and are closely scruntinized by a wide spectrum of forest users. This study examines the reliability of harvest calculations on a single national forest in New Mexico Forest Service determinations of an array of variables were reviewed and evaluated. The study revealed a lack of precision in Forest Service adherence to self-imposed procedural standards governing the calculation process. Timber sales have taken place on lands where such standards prohibit harvesting and these lands have been included in annual harvest calculations. Assumptions required by a mathematical model used by the Forest Service in calculating the harvest were not followed in the subsequent implementation of the harvest level. These factors suggest that the Forest Service could have significantly over-stated annual harvest rate for the first decade. Opportunities exist to improve the calculation, and benefits realized may greatly exceed additional costs of implementation     

Wildfire Policy and Public Lands: Integrating Scientific Understanding with Social Concerns across Landscapes

Abstract:  Efforts to suppress wildfires have become increasingly problematic in recent years as costs have risen, threats to firefighter safety have escalated, and detrimental impacts to ecosystems have multiplied. Wildfires that escape initial suppression often expand into large, high-intensity summer blazes. Lost is the legacy of smaller fires that likely burned outside extreme weather and fuel conditions and resulted in less severe impacts. Despite the recognized need for modifications to existing policies and practices, resource agencies have been slow to respond. The spread of exotic species, climate change, and increasing human development in wildlands further complicates the issue. New policies are needed that integrate social and ecological needs across administrative boundaries and broad landscapes. These policies should promote a continuum of treatments with active management and reduction of fuel hazard in wildland-urban interface zones and reintroduction of fire in wildlands. Management goals should focus on restoration of the long-term ecological health of the land. Projects that reduce fuel loads but compromise the integrity of soil, water supplies, or watersheds will do more harm than good in the long run. Despite significant ecological concerns, learning to live with fire remains primarily a social issue that will require greater political leadership, agency innovation, public involvement, and community responsibility.     

新型城镇化背景下城乡环境基本公共服务均等化推进路径

新型城镇化迫切需要推进城乡环境基本公共服务均等化,而农村环境公共服务的不足成为实现环境基本公共服务均等化的阻碍和制约。在阐述新型城镇化和城乡环境基本公共服务均等化之间关系的基础上,从环境基本公共服务投入总体不足、供给主体单一、城乡不均等突出等方面指出:当前阶段城乡环境基本公共服务均等化现状和面临的问题。探讨了城镇化背景下城乡环境基本公共服务均等化的发展重点领域,包括饮用水安全保障、清洁的大气、污水垃圾治理设施、环境信息服务等,认为推进城乡环境基本公共服务均等化宜采用政府推动、市场参与、多元化供给的协调推进路径,并提出政策建议。     

铁路劳动安全面向二十一世纪若干问题的探讨

论述了铁路劳动安全面向二十一世纪的几个对策性措施：确立铁道安全的正确观念，开展铁路安全评估，推行铁路安全文化，规划建设铁路劳动安全社会化服务体系     

Geographic information systems within the national health service: the scope for implementation

The paper starts by assessing some of the needs for information management within the health service in Great Britain. Geographic Information Systems are introduced, and some of the functions such as database management, networking and overlying are described. Principally, it is argued that GIS can fill the role as a health information system, resource management system, and has the potential to assist in family practitioner monitoring and epidemiological studies.