生态补偿对象的空间选择研究——以甘南藏族自治州草地生态系统的水源涵养服务为例

生态补偿对象的空间选择研究是生态补偿机制的基础性和支撑性研究,对建立高效合理的生态补偿机制具有十分关键的作用。目前国内在生态补偿的理论和实践研究中很少专门研究补偿对象的选择问题,这种不考虑空间异质性对整个补偿区域实施统一的标准补偿势必会影响到补偿的效率。有鉴于此,基于补偿资金效率考虑,构建以土地所有者提供的生态系统服务、土地所有者的参与成本和生态系统服务受损风险为参数的空间选择模型,以甘南藏族自治州草地生态系统水源涵养服务为例,乡镇为基本研究单元,采用聚类分析法将全州划为五大等级补偿区:优先补偿区、次级优先补偿区、次级补偿区、临界补偿区和潜在补偿区或可能补偿区。对各级补偿区的特征分析结果表明:①草地生态系统的优先补偿主体主要分布在纯牧区,而非优先补偿区主要分布在半农半牧区、林业区和农业区;②基于补偿资金效率考虑的补偿优先度与草地生态系统退化风险呈现高度的吻合状态,草地生态系统的优先补偿区又是高退化风险区(生态脆弱区);③草地生态系统的补偿效率与生态重要性呈现出吻合的状态,即草地生态系统的优先补偿区又是重要生态功能区;④甘南州近17%的草地为低效率和无效率补偿区,也是非生态脆弱区和非重要生态功能区,基于生态脆弱性、生态重要性和补偿效率考虑,这部分草地可暂时给予较低标准的补偿。     

基于IDL Export Bridge技术的湖泊水环境遥感监测系统设计

通过使用IDL连接桥(IDL Export Bridges)技术,构建可调用IDL运行库的COM封装对象;并结合.NET在开发Windows桌面应用程序方面的优点,设计开发能够满足业务化需求的湖泊水环境遥感自动化监测系统.该系统可对多种遥感影像进行预处理,并针对不同湖泊区域进行水质参数反演,最终完成制图输出和报告文档.     

保障性住房租购选择研究

在当前保障性住房供给与需求矛盾不断加深的背景下,研究保障对象对保障性住房的租赁或购买的需求特征及其关键影响因素,具有较强的必要性与现实意义。本文通过问卷调查方式获取城市中心城区受保障对象的需求特征数据,从保障对象住房需求的视角,分析影响保障性住房租赁或购买选择的相关因素。文中构建了Logit模型,并检验各因素对保障性住房租购选择的影响关系及强度。结果显示:(1)住区环境、个体特征、家庭特征、住房特征等四大类因素对保障性住房租购选择产生显著的影响;(2)住区环境中,教育资源、交通配套设施等是影响保障性住房租购选择的关键指标,这些关键指标的改善,将会使保障对象更倾向于购买保障房而不是租赁;(3)个体特征中,性别与年龄对保障性住房租购选择影响最大,相比男性、年轻人,女性、年长者更倾向于购买保障性住房而不是租赁;(4)家庭特征方面,人口数量多、经济收入高等特征的家庭更愿意选择购买保障房,但家庭人口数量的影响大于家庭经济收入;(5)住房特征中,居住稳定性对保障性住房租购选择影响最大,其次是保障性住房准入政策合理性、住房面积及户型,这些因素的改善,都将提高保障对象对保障性住房做出购买的决策。因此,提供多形式、多条件的保障性住房,才能满足不同保障对象的租赁或购买的需求。设置合理的保障性住房准入条件,构建科学合理规范的保障性住房供给标准和住房保障运行机制,才能使迫切需要租购保障房的家庭从中受益。     

流域水生态功能分区与质量目标管理技术研究的若干问题

制定中国的水生态功能分区方案、提出流域水环境质量目标管理技术体系是解决中国流域污染控制的重大科技需求,不仅可以提升我国水污染控制的科技水平,而且对于我国流域水生态安全保障具有现实意义.本文对水生态功能分区与质量目标管理的意义、概念、研究现状以及未来发展趋势进行了研究.阐述了流域水生态功能分区与质量目标管理技术研究的迫切...     

城市公共安全监管对象风险调查系统研究

随着城市的不断发展,生产经营企业也日益增多,随之也带来很多城市风险。为了维护城市和谐,保障人民生命财产安全,必须采取有效措施控制或降低城市风险。该项目采取调查城市监管对象实际现状为依据,运用科学的模型方法分析计算。同时为增加软件的灵活性,系统的风险调查表指标内容、赋分标准、指标权重等内容都可以根据实际应用情况相应调整。实践证明,该方法能较准确的计算出监管对象风险状况,为下一步消除风险提供技术支持。     

基于高分数据的村级地块面向对象分类方法研究

针对农作物对地抽样调查工作中村级抽样单元野外调查工作量大的问题,研究了一种基于高分数据的村级农作物种植面积提取方法。以辽宁省北镇市孟家村SPOT5遥感影像为实验数据(主要包括农田、裸地、道路、大棚、水体、房屋等类型),基于eCognition平台,根据局部方差法筛选地物最优分割尺度,按照最优分割尺度从大到小组织实验区地物分割次序,结合影像对象的光谱、形状等特征,建立分类规则,完成了村级农作物种植面积的提取。该方法有效避免了在影像分割时参数反复试错带来的复杂性和随机性,提高了农作物种植面积面向对象分类精度和效率。通过野外调查样地进行精度验证表明,精度达到90.4%,为提高农作物种植面积对地抽样调查工作效率,减少野外调查的工作量提供技术支撑。     

Injury Outcome in Crashes with Guardrail End Terminals

Objective: The goal of this study is to evaluate the crash performance of guardrail end terminals in real-world crashes. Guardrail end terminals are installed at the ends of guardrail systems to prevent the rail from spearing through the car in an end-on collision. Recently, there has been a great deal of controversy as to the safety of certain widely used end terminal designs, partly because there is surprisingly little real-world crash data for end terminals. Most existing studies of end terminal crashes used data from prior to the mid-1990s. Since then, there have been large improvements to vehicle crashworthiness and seat belt usage rates, as well as new roadside safety hardware compliant with National Cooperative Highway Research Program (NCHRP) Report 350, “Recommended Procedures for the Safety Performance Evaluation of Highway Features.” Additionally, most existing studies of injury in end terminal crashes do not account for factors such as the occurrence of rollover. This analysis uses more recent crash data that represent post-1990s vehicle fleet changes and account for a number of factors that may affect driver injury outcome and rollover occurrence.

Methods: Passenger vehicle crashes coded as involving guardrail end terminals were identified in the set of police-reported crashes in Michigan in 2011 and 2012. End terminal performance was expected to be a function of end terminal system design. State crash databases generally do not identify specific end terminal systems. In this study, the coded crash location was used to obtain photographs of the crash site prior to the crash from Google Street View. These site photographs were manually inspected to identify the particular end terminal system involved in the crash. Multiple logistic regression was used to test for significant differences in the odds of driver injury and rollover between different terminal types while accounting for other factors.

Results: A total of 1,001 end terminal crashes from the 2011–2012 Michigan State crash data were manually inspected to identify the terminal that had been struck. Four hundred fifty-one crashes were found to be suitable for analysis. Serious to fatal driver injury occurred in 3.8% of end terminal crashes, moderate to fatal driver injury occurred in 11.8%, and 72.3% involved property damage only. No significant difference in moderate to fatal driver injury odds was observed between NCHRP 350 compliant end terminals and noncompliant terminals. Car drivers showed odds of moderate to fatal injury 3.6 times greater than LTV drivers in end terminal crashes. Rollover occurrence was not significantly associated with end terminal type.

Conclusions: Car drivers have greater potential for injury in end terminal crashes than light truck/van/sport utility vehicle drivers. End terminal designs compliant with NCHRP 350 did not appear to carry different odds of moderate driver injury than noncompliant end terminals. The findings account for driver seat belt use, rollover occurrence, terminal orientation (leading/trailing), control loss, and the number of impact events. Rollover and nonuse of seat belts carried much larger increases in injury potential than end terminal type. Rollover did not appear to be associated with NCHRP 350 compliance.     

快速成形技术的新进展

快速成形技术是集机械、电子、光学、材料等学科为一体的先进制造技术之一。论述了快速成形技术的起源,介绍了快速成形技术的应用领域及其市场分布情况。在阐述了各成形工艺在国内外新进展的基础上,讨论了该技术的发展趋势。     

环境规划与城市总体规划比较分析

环境规划与城市总体规划是相互联系和渗透,同时又各有侧重,具有相对独立性的两种规划.城市总体规划的研究对象是一定时期的某城市,而环境规划则是针对“社会-经济-环境“这一大的复合生态系统;城市总体规划具有城市建设发展纲领的性质,而环境规划则更侧重于污染防治和生态保护与建设;从与可持续发展的关系来说,环境规划更侧重环境保护的重要意义,而城市总体规划则是城市建设发展的蓝图,对城市经济、社会和人口、资源、环境等都具有指导和控制作用,涉及面更广.另外,两种规划的编制、审批和管理单位也不同.     

环境保护“十二·五”规划——目标、任务与动力

围绕国家和自治区的总体要求,结合包头市实际,明确了包头市十二.五环境保护工作的指导思想、总体目标,以削减总量、改善质量、防范风险为主线,按环境要素提出了十二.五环境保护工作的重点任务和动力机制,为科学编制十二.五环境保护规划奠定了基础。