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1.
基于PSR框架模型的东溪流域生态系统健康评价 总被引：16，自引：2，他引：14
本文根据联合国OECD和UNEP提出的“压力-状态-响应”（PSR）框架模型和流域生态系统的特点,通过建立流域生态系统健康评价的指标体系和评价模型,对福建省诏安东溪流域的生态系统健康状态进行评价。研究的基本思路是：首先,选取人口密度、GDP年增长率、人均拥有水资源量、年降雨量、森林覆盖率、工业废水达标处理率等能够充分反映流域压力、状态和响应的指标构建评价指标体系;其次,通过专家打分的方法对各评价指标进行权重分配,参考湿地的生态系统健康评价方法和相关标准对流域生态系统健康评价的各个指标进行标准化赋值;再次,提出了流域生态系统健康综合评价模型,得出流域生态系统健康综合指数;最后。把流域生态系统健康状态分为5个等级,分别是：良好状态、较好状态、警戒状态、较差状态和极差状态。根据流域生态系统健康综合指数,确定流域生态系统健康状况。研究结果表明,东溪流域生态系统健康评价指数（E）为0．5898。东溪流域生态系统健康处于警戒状态。 相似文献
2.
典型农牧交错区农业生态系统健康测度及其持续利用对策 总被引：2，自引：0，他引：2
生态系统健康作为全球管理的新目标,作为分析生态系统的新方法而受到青睐,是现代生态学的研究热点之一。本文根据生态系统健康的内涵和农牧交错带农业生态系统的特点,从活力、组织结构和恢复力3个方面选取18个指标,构建了农牧交错带农业生态系统健康的评价指标体系。在此基础上建立综合评价模型,应用于赤峰12个旗（区、县）,得到如下结果：农业生态系统健康状况处在“健康”标准是红山区和巴林右旗;处在“临界健康”标准是克什克腾旗、元宝山区、敖汉旗、松山区;处在“不健康”标准是宁城县、林西县、巴林左旗、喀喇沁旗、阿鲁克尔沁旗、翁牛特旗。评价结果基本上反映了当地农业生态系统的健康状况,说明建立的评价指标体系与模型是可行的。最后提出了农牧交错带农业生态系统持续利用的对策。 相似文献
3.
基于生态足迹模型的陕西省可持续发展动态研究 总被引：1，自引：0，他引：1
本文对陕西省2001—2010年的生态足迹及生态承载力进行了动态量化计算,并引用生态压力指数、万元GDP生态足迹、生态足迹多样性指数和生态系统发展能力等指标对计算结果进行了进一步分析。结果表明:陕西省近10年发展一直处于生态赤字状态,人均生态足迹年均增长率达到7.856%,生态赤字年均增长率高达15.772%;造成这种现象的主要原因是经济发展对建筑用地和化石能源用地的过度耗用;近10年陕西省的生态压力指数均大于1,且呈现增强的趋势,但万元GDP生态足迹则出现明显下降趋势,说明对资源利用效率显著提高;生态系统发展能力也有很大提升,但是2010年已超出其发展潜力,经济社会与自然资源的发展持续性出现矛盾,生态经济发展处于相对不可持续发展状态。 相似文献
4.
太湖流域生态系统健康的空间分异及其动态转移 总被引：8，自引：2，他引：6
根据研究地域的生态特征,综合考虑流域内生态系统相互影响机制,结合遥感解译、野外调查及社会统计等多源数据,运用PSR模型从胁迫因子、状态因子以及效应因子三方面构建了流域生态系统健康评价指标体系,对太湖流域综合生态健康进行评价,并对其空间分异及动态转移特征进行深入分析。结果表明:2000年-2008年间,研究区域生态系统健康状况整体处于亚健康水平,区域综合生态健康指数由2000年的0.584下降至2008年的0.512,有92%的区域综合生态健康指数呈下降态势。生态健康存在明显区域性差异,整体呈现由东北至西南逐渐下降的趋势。生态健康状态较好的区域主要集中在西南部苕溪流域的安吉县、德清县及长兴县一带,而生态健康较差的区域主要分布于东北部的无锡市区和常州市区。 相似文献
5.
根据2013-2014年对乐清湾海域生态环境的综合调查结果,采用《近岸海域生态健康评价指南》(HY/T087-2005)中的河口及海湾生态系统健康评价方法对该海域的生态系统健康状况进行评价和分析。结果显示,水环境健康指数、沉积物健康指数、生物残毒健康指数、栖息地健康指数和生物健康指数分别为10.89、10.00、8.87、5.00和16.46,海域生态健康指数为51.22。表明,乐清湾海域水环境处于亚健康状态,沉积环境处于健康状态,未受生物残毒污染,而栖息地和生物指标处于不健康状态。综合5类评价因子的的评价结果,判定该海域生态环境处于亚健康状态。 相似文献
6.
【目的】探究荒漠绿洲三生用地变化及其生态效应,可为黄河流域生态保护和高质量发展提供决策参考。【方法】本文以1990—2020年黄河上游荒漠绿洲区——银川市为例,提出了生态系统服务价值（ESV）当量因子的系数修订方法,建立了银川市与全国ESV当量因子的系数关系,分析了ESV对三生用地时空变化的响应特征。【结果】结果表明：①生态用地在银川市三生用地中比例最高,但研究时段内有所降低,由1990年的69.49%下降为2020年的57.68%,同期,生产用地稳中有增,由28.54%提升为32.52%,生活用地扩张迅速,由2.37%提升为9.81%;生活用地动态度变化剧烈,生产用地与生态用地动态度渐趋平缓。②1990—2020年ESV总量增加了38423.65万元,生态用地质量提升对ESV的增加效应大于生产用地和生活用地扩张导致的ESV降低效应;结构上,调节服务对ESV的贡献最大且持续提升,比例从1990年的82.29%增为2020年的83.76%,其他服务比例均有所降低。③城市扩张、能源基地建设、移民迁入等因素是导致ESV下降的重要原因,导致城区、宁东能源基地和重点移民迁入区ESV降低;生态建设是ESV的提升主因,白芨滩自然保护区、黄河生态带核心区以及贺兰山东麓葡萄长廊等区域的ESV增加明显。【结论】今后发展中,需要提升生活用地和生产用地的效率以降低其扩张速率,以降低挤占生态用地的压力,同时,需要持续改善生态用地质量,以促进荒漠绿洲生态系统健康可持续发展。 相似文献
7.
新时代创新引领发展对培育和优化创新生态系统提出新要求,需要准确客观评价区域创新生态系统健康状况。基于传统生态位适宜度模型进行改进修正,采用PCA分析法对生态因子赋权以解决评价指标共线性问题,提炼创新生态系统的开放性、多样性与协同性、演进性与成长性、可持续性等固有特征,从特性角度重构区域创新生态系统健康评价指标体系。从描述性分析和定量分析两个角度对省域和城市两个不同层次的区域创新生态系统进行健康评价。研究表明,模型与指标适合评价创新生态系统的健康度;我国区域创新生态系统健康度不平衡状况仍在加剧。培育优化创新生态系统要注重久久为功,突出新增长极,形成内生动力,促进创新行为者融合共生。 相似文献
8.
流域生态系统健康评价研究 总被引：16，自引：2，他引：14
以流域为单元,评价生态系统健康状况,将为流域的规划、管理和保护以及流域综合治理提供决策依据。总结了国内外关于流域生态系统健康评价的方法,对流域生态系统健康评价体系的理论基础、基本框架、指标选择、指标的评价函数、权重分配、体系建构步骤等关键性问题进行了研究。以“自然条件限制因子-流域生态健康指示因子-人类活动影响因子”评价体系为基础,选择了水质、植被、水土保持、生物多样性、湿地、土地利用、人口、点源污染、面源污染、水资源开发利用率、河流自然化、人均GDP、土壤、水文和生物第一性潜在生产率等20项指标,构建每个评价指标的评价函数,利用层次分析法对滦河山区流域和北四河平原流域进行生态系统健康评价。综合评价结果表明,滦河山区流域和北四河平原流域生态系统健康得分为76和46,年降雨量、点源污染、面源污染、水资源开发利用率是我国北方半湿润/半干旱地带小流域生态系统健康状况的主要控制因子。 相似文献
9.
生态系统健康作为全球管理的新目标,作为分析生态系统的新方法而受到青睐,是现代生态学的研究热点之一.本文根据生态系统健康的内涵和农牧交错带农业生态系统的特点,从活力、组织结构和恢复力3个方面选取18个指标.构建了农牧交错带农业生态系统健康的评价指标体系.在此基础上建立综合评价模型,应用于赤峰12个旗(区、县),得到如下结果:农业生态系统健康状况处在"健康"标准是红山区和巴林右旗;处在"临界健康"标准是克什克腾旗、元宝山区、敖汉旗、松山区;处在"不健康"标准是宁城县、林西县、巴林左旗、喀喇沁旗、阿鲁克尔沁旗、翁牛特旗.评价结果基本上反映了当地农业生态系统的健康状况,说明建立的评价指标体系与模型是可行的.最后提出了农牧交错带农业生态系统持续利用的对策. 相似文献
10.
数字经济的蓬勃发展正在有力地推动着乡村的全面振兴,淘宝村、淘宝镇的涌现正是其重要体现,农村电商创业生态系统与新创企业之间的影响机制也因此成为一个关键问题。尽管现有文献已经探讨了创业生态系统的组成要素和关键参与者,但是在解释创业生态系统的竞争力和系统中新创企业绩效方面仍显不足。许多研究都强调了生态系统的健康性在创业生态系统持续发展过程中发挥的关键作用,它会影响所有生态系统参与者的命运。创业生态系统内资源相对稀缺,通过创业拼凑的方式是新创企业取得发展的有效途径之一。从微观的企业视角出发,在分析理解创业生态系统理论和创业拼凑理论的基础上,依据“环境感知—行为—结果”的研究逻辑,构建“创业生态系统健康性—创业拼凑—新创企业创业绩效”的理论模型,采用问卷调查方法,以泽国镇农村电商创业生态系统中的电商企业为研究对象,采用统计分析软件SPSS 22.0和AMOS 24.0对收集的605家电商企业的样本数据进行信效度检验,并构建结构方程模型,对假设进行检验,实证结果显示：（1）创业生态系统中生态稳定性和生态多样性对新创企业创业绩效具有正向影响;（2）创业拼凑对新创企业创业绩效具有正向影响;（3）创业生... 相似文献
11.
《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
12.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
13.
《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
14.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
15.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
16.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
17.
Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献
18.
Milton Mueller 《The Information Society》2001,17(3):151-163
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP. 相似文献
19.
Prof. Raymond C.K. Chen a neuropsychologist with the CAS Institute of Psychology has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.…… 《中国科学院院刊(英文版)》2008,22(1):15-15
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology. 相似文献
20.
Prof. SUN Changpu from the CAS Institute of Theoretical Physics coworkers from University of Basel in Switzerland have worked out a way - at least in theory - to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams is similar to the famous Stern-Gerlach effect whereby a beam of atoms passing through a magnetic field is split in two according to the atoms' spin states 《中国科学院院刊(英文版)》2008,22(1):23-23
Prof. SUN Changpu from the CAS Institute of Theoretical Physics and coworkers from University of Basel in Switzerland have worked out a way --at least in theory --to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams and is similar to the famous Stern-Gerlach effect, whereby a beam of atoms passing through a magnetic field is split in two according to the atoms＇ spin states （Phys. Rev. Lett. 99 130403）. 相似文献