北方农牧交错区草地生态系统服务间接价值的初步评估——以太仆寺旗和沽源县境内为例

以草地地上生物量为基础,运用经济学的市场价值法、物质量法、水量平衡法等方法对太仆寺旗和沽源县境内的农牧交错区草地的固定CO2、释放O2、土壤侵蚀控制、涵养水源、营养物质循环5项生态系统服务功能进行初步的评估。结果表明：由这5项功能构成的生态系统服务的间接价值在农区为16 668元/（hm2·a）,在草原区为17 223元/（hm2·a）。尽管草原区的间接价值比农区的高3.33%,但研究所选的农牧交错区由于农业活动的干扰,并没有导致草地生态系统服务功能间接价值的显著下降。这说明维持现阶段的农业活动或退耕还草可能促进草地生态系统生态经济价值的可持续性发展;但若继续开垦和破坏草地,草地生态系统的服务功能可能会显著下降,草地所具有的生态屏障作用也会减弱甚至消失。     

Clients’ perceptions of delivery of veterinary services in peri-urban Ghana

A study was designed aimed at comparing the assessment of performance of animal health care delivery systems in peri-urban Ghana by livestock and poultry keepers in 4 locations. 889 respondents were interviewed using a questionnaire. A higher proportion of respondents in Location 1 met their needs for animal health by themselves, while in Location 3 these needs were met mainly by veterinarians. The mean distances to veterinary clinics, veterinary technicians or to purchase medicine were significantly higher in Location 1. Higher proportions in 3 locations perceived effectiveness of service delivery to be good. However, equity was poor in all 4 locations. Higher proportions in Locations 2, 3 and 4 said services were unaffordable. Client needs were perceived to have been met by higher proportions in Locations 3 and 4 but not in Locations 1 and 2. Staff attitude and technical competence were good in all 4 locations. The study concluded that the differences reported in the quality of service indicators in the 4 locations were not critical enough to recommend location-specific delivery systems.     

基于XML与Web服务的齿轮制造信息的共享与集成

为实现齿轮企业内各应用系统间的信息共享与集成,加快企业信息化进程,提出了基于可扩展标示语言（extensive makeup language,XML）与Web服务的齿轮制造信息共享与集成解决方案。研究了齿轮企业内EXPRESS数据模型与XML模型的映射机制,实现了产品模型数据交换标准（standard exchange of product data model,STEP）中性文件的XML转换和表达,并利用Web服务技术实现了齿轮信息共享服务平台的集成框架构建与软件开发。最后,通过圆柱斜齿轮的网络化磨削加工试验,来验证该信息共享与集成方案的可行性与实用性。试验结果表明,本文所提出的信息共享与集成方案,能有效实现齿轮企业各应用系统间的信息交流与共享,满足齿轮企业信息化建设的需求。     

西北干旱监测预警评估业务系统开发与应用

利用VS 2005,SQL2005,Surfer 8.0等工具开发建成了"西北区域干旱监测预警评估业务系统",该系统为西北区首个区域性的干旱监测预警评估业务系统.该系统为B/S架构的网络化软件,业务用户可以通过网络操作获得西北各省区丰富的气象干旱、农业干旱、生态干旱等数据信息.该系统实现了对干旱监测、预警、评估等业务工作的支持,能够进行标准化降水指数,相对湿润度指数,综合干旱指数,彭曼蒸散,作物水分亏缺度,水资源评估,干旱灾情评估等50多种指标模型的自动计算,可为大气、农业、生态等领域的干旱监测预警评估提供丰富的图形、表格和文本等数据信息.该系统集成度高,运行过程基本为自动处理.目前该系统已经在西北区域的干旱监测预警评估业务中运行,并为西北区域和各省干旱监测预警业务提供了有力支持.     

森林生态系统健康快速评价研究

运用北京市"十五"森林资源二类清查数据,以北京市西山林场为例,从森林生态系统的完整性、稳定性、可持续性建立森林生态系统健康快速评价指标体系.使用层次分析法确定指标权重,运用综合评价模型对森林小斑尺度上北京市西山林场森林生态系统健康状况进行了评价.结果表明,(1)北京西山林场367个小斑中,70.3%的小斑处于亚健康状态.(2)确定的3类8个指标,能比较客观地反映北京市西山林场森林生态系统的健康状况,且简便易用,具有一定的科学性和可操作性.     

自由分类法在图书馆信息管理中的应用

自由分类法是随网络技术发展起来的一种新的信息组织方式,提供了一个用户高度参与的集体智慧平台。图书馆资源管理应从信息管理转变为知识管理,为教学与科研创新服务,用新技术提升资源管理与传播的水平。     

基于电子阅览室为平台的数字资源服务效益研究

电子阅览室建设是适应图书馆数字资源建设的需要而发展起来,它配置了优良的软硬件设施和较好的人力资源,提供了数字资源阅读场所。电子阅览室开展的检索培训、实践、导读、答疑等工作,提高了数字资源的服务效益。     

Assessing turnover of microbial biomass phosphorus: Combination of an isotopic dilution method with a mass balance model

Microbial biomass phosphorus (P) can play an important role in P cycling and availability to plants by acting as a source (remineralization) or sink (immobilization) of phosphate ions (iP). To assess the role of the microbial P pools, both the dynamics (i.e. the turnover) and the size of the microbial P pools were studied in forest soils. Combining an isotopic dilution method with a modelling approach, we showed the existence of two pools of microbial P with different dynamics and therefore of different importance in soil P availability and cycling. In particular, we showed that the largest pool of microbial P (80%) had a fast turnover (nine days). Microbial P increased with an increase in soil organic matter and represented up to 53% of total P in contrasting forest soils. By combining these results with the turnover times of microbial P obtained in the modelling study, we evaluated that 8.5-17.3 kg P ha⁻¹ of microbial P could turn over in a few days. This suggests that microbial biomass P is a potentially significant source of available iP, and that micro-organisms can play a major role in P cycling in the forest studied here. However, microbial biomass can also be in competition with the trees since most of the remineralized P could be immobilized again in the microbial turnover.     

基于CVM的岷江上游森林生态系统服务价值评估

采用条件价值评估法(CVM),以支付卡形式设计了498份调查问卷,在2008年对岷江上游森林生态价值调研的基础上,于2011年再次调查了岷江下游居民对上游森林生态系统服务的支付意愿(WTP)。结果表明,2011年岷江下游居民中,有69.02%对岷江上游森林生态系统服务存在支付意愿,与2008年相比,提高了8.22%,平均支付意愿为每年36.51元,与2008年相比,降低了7.49元。根据岷江下游现有的家庭总数进行计算,2011年岷江上游森林生态系统服务价值是1.4亿元。利用Logistic模型对影响居民支付意愿的因素进行了定量分析,并在此基础上提出了相关的政策建议。     

云阳县喀斯特地区生态系统退化的原因及对策

总结了云阳县喀斯特地区的地貌类型和生态环境特点,分析该脆弱生态系统退化的原因。针对该地区贫困与生态环境退化的现状,提出生态重建与发展经济的对策。