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1.
闽三角城市群生态网络分析与构建 总被引：2，自引：0，他引：2
快速城镇化进程导致区域生境斑块日益破碎化和孤岛化,科学构建生态网络是有效连接生境斑块的重要手段,对保障区域生物多样性和生态安全具有关键意义。以闽三角城市群为研究对象,依照“生态源地识别—阻力面设置—潜在廊道模拟”模式,根据生物栖息地适宜性评价识别生态源地,采用夜间灯光数据修正传统土地覆被赋值确定生态阻力面,基于最小累积阻力模型模拟潜在生态廊道。在此基础上,结合潜力模型进行廊道重要性评价,通过计算网络连通性指数和经济成本比确定廊道提取的合理阈值,提出生态与经济并重型生态网络构建方案。研究结果表明：①识别的生态源地共计45处,总面积约为3542 km2;模拟的潜在生态廊道共计990条,总长度约为5941 km。②源地及廊道的分布均呈现出显著的空间分异,研究区西北部山区丘陵地带的德化县、安溪县、南靖县等分布较为密集,而东南沿海建成区几乎没有分布。③0.73分位数所对应的网络连通性指数成本比达到最高值,此方案下提取的268条潜在廊道可有效连通45处生态源地。研究结果从生态保护与经济发展兼顾视角合理构建区域生态网络体系,可为闽三角城市群生态网络的建设优化提供科学依据。 相似文献
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【目的】构建生态网络、优化生态空间布局，对协调区域社会经济和生态环境可持续发展具有重要作用。【方法】本文以陕西省为例，在土地利用变化(LUCC)分析和生态系统服务价值(ESV)定量评价基础上，利用MSPA方法、Linkage Mapper工具等手段构建生态网络，并进一步展开了生态空间优化布局研究。【结果】(1)陕西省各地类面积在2000—2020年间发生了显著变化，期间面积(绝对值)变化从大到小依次为：耕地>林地>建设用地>草地>未利用地>水域；(2)陕西省生态系统服务价值在2000—2020年增加了47.84亿元，其空间分布格局总体保持稳定，高价值区主要分布在秦岭、巴山和延安市南部，低价值区集中分布在关中地区；(3)识别30处生态源地总面积约46465.92 km2，提取生态廊道62条、生态夹点36个、生态障碍点85个，共同组成生态网络；(4)提出“五带、六区、多廊道、多组团”的生态空间优化布局方案，为陕西省生态空间的修复管理提供了参考。【结论】从LUCC及ESV变化出发构建生态网络，识别生态空间中的问题区域并提出针对策略，可有效解... 相似文献
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青藏高原是我国乃至亚洲的重要生态安全屏障区和全球生物多样性保护的热点地区，保障生态安全是青藏高原生态保护的核心任务。青藏高原物种丰富但受威胁物种多。近15年来青藏高原生态安全屏障生态系统格局稳定，生态系统质量整体趋好，水源涵养、土壤保持和防风固沙服务均得以提升，生态退化趋势得到遏制，自然保护地建设和生态保护建设工程对提升生态屏障功能发挥了关键作用。然而，受气候暖湿化和人类活动影响，青藏高原生态安全屏障仍然面临退化草地面积大，以及冻土面积萎缩、沼泽湿地减少、部分生物栖息地退化、外来物种入侵、局部生态系统退化等生态风险。为了进一步保护青藏高原生态安全屏障功能，建议优化调整自然保护地空间格局，建立以国家公园群为主体的自然保护地体系和加快实施青藏高原生态安全屏障保护修复工程。 相似文献
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长期生态学监测和研究揭示了北亚热带森林生物多样性和生态系统的结构功能及维持机制,阐明了干扰对生物多样性和生态系统的影响过程;凝练出神农架自然遗产的全球突出价值,构建的"廊道-踏脚石-关键栖息地"保护体系提升了自然保护地的生态系统原真性和完整性;提出了重点生态功能区生物多样性保护和生态恢复的关键技术体系及应用模式。长期生态学研究为我国亚热带山地森林生态系统研究和生物多样性保护、生态建设和经济社会可持续发展提供基础理论和技术支撑。 相似文献
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基于多源数据综合观测的生态安全格局构建——以江西省万年县为例 总被引：2，自引：0，他引：2
全面掌握区域自然资源现状,以此为数据基础进行生态安全格局优化,对综合开发及统筹布局自然资源具有重要意义。开展自然资源综合观测、识别区域生态保护及修复节点是安全格局构建的关键环节。本文选取江西省万年县为研究区,通过土地利用类型、DEM、道路数据和自然保护地数据对区域资源现状进行综合观测;同时基于InVEST模型、粒度反推法以及区域现状确定生态源地;结合土地利用类型、地形以及道路因子构建综合阻力面;并使用电路理论判定生态廊道,识别生态修复关键点。结果表明：①万年县生态源地面积95.93 km2,林地为主要源地类型,其对于区域生态安全格局的稳定至关重要;生态廊道长度217.89 km,其中,贯穿全域的33条关键廊道需要优先保护,未来可作为自然资源综合观测及监测的重点区域。②识别出“夹点”11处,“障碍点”74处,区域生境连通性仍有较大提升空间。③基于电路理论,通过源地选取、阻力面及廊道构建、重要战略点识别等,整合全域山水林田湖草自然资源,针对生态安全格局提出不同分区的资源优化策略,对于提高区域资源供给能力具有积极的实践意义。 相似文献
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《中国科学基金》2021,(4)
黄河流域是连接青藏高原、黄土高原和华北平原的生态廊道,也是我国"一带一路"建设的重要经济廊道,对国家的经济社会发展和生态安全都具有重要意义。受气候变化和人类活动影响,近几十年来黄河流域生态系统的结构和功能发生了巨大变化,流域生态系统的健康受到威胁。然而,目前仍缺乏对黄河流域生态系统在流域尺度上的整体性研究,对其完整性、连通性和脆弱性的系统研究不足,难以有针对性地提升变化环境下的生态系统服务与生态屏障效应。围绕黄河流域生态保护与高质量发展的重大战略需求,我们认为应从流域整体性出发,通过构建黄河流域生态系统类型及空间格局数据集,分析黄河流域生态水平衡分量的格局变化规律,解析并量化表征气候变化和人类活动与生态系统变化之间的关联;基于多源数据集以及生态水文模型,解析黄河流域生态系统的时空格局变化和生态水文过程,并以此建立关键生态系统服务的定量评估指标体系,揭示关键生态系统服务供给能力的格局特征和空间流动及变化趋势,开展生态系统服务格局特征与空间流动时空变异的归因分析;阐明生态系统结构—过程—服务的级联效应,提出生态屏障功能的优化提升方案,为黄河流域生态治理与管理提供科技支撑。上述研究对完善和丰富地球系统科学具有重要的理论和现实意义。 相似文献
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为了探究互联网给产学研协同创新中的知识增值带来的影响。本文从知识生态视角出发，构建了基于互联网的产学研协同创新知识生态系统模型，并运用生态机制解释其中的知识增值过程。在此基础之上，引用“华为&清华”协同创新案例，基于现实数据构建知识增值系统动力学模型，并运用Vensim PLE软件进行仿真。研究表明，互联网可通过改善知识种群的知识创新环境、增强知识种群的知识转移能力和知识转移意愿、为知识种群提供知识服务来促进产学研协同创新中的知识实现增值。最后，针对如何最大程度发挥互联网在促进知识增值方面的作用，提出相关建议。 相似文献
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建立自然保护区是保护典型生态系统和生物多样性及珍稀濒危物种资源的基本途径。具有敏感生态系统和丰富生物多样性的青藏高原,其自然保护区建设及其成效一直以来是各界关注的重点问题。本文以最新的《全国自然保护区名录》和已发表NPP与保护成效数据为基础,分析了青藏高原保护区的组成、分布格局与保护成效。结果表明:11963年至今,青藏高原地区建成了各类保护区155个,面积达82.24万km2,占全高原面积的32.35%;2保护区类型主要以野生动物与荒漠生态系统、野生动物及其生态系统、野生动物3个类型为主,各占高原内保护区总面积的36.84%、33.35%和6.80%;3形成了以超大型保护区为主、中部和东南部分布为主、保护类型多样为特点的青藏高原自然保护区体系;4经过50余年的生态建设,保护区保护成效显著,主要表现为:珍稀濒危物种数量显著增加、濒危物种西藏马鹿被重新发现、野生动物的栖息地得到了恢复和改善及典型保护区内草地植被的生态功能增强。本研究结果可为青藏高原生物多样性保护研究和区域可持续发展提供科学参考。 相似文献
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北方草地是我国重要的绿色生态屏障,也是黄河、长江、澜沧江、滦河等江河的发源地和水源涵养区,其对保障我国生态安全,提升生态系统服务和生态系统稳定性具有极其重要的作用。长期以来,我国在畜牧业生产中重视草地的生产功能,而忽视其生态功能,导致生产功能过度利用,以及生态系统服务和生态功能降低,继而严重威胁着我国的生态安全。开展北方草地生态系统服务评估,制定北方草地主体功能区划,是构建和优化生态安全屏障体系,科学配置草地的生态-生产功能,推进生态文明,统筹山水林田湖草一体化保护和修复,建设"美丽中国",实现人与自然和谐共生的国家重大科技需求。文章基于北方草地生态系统服务和资源环境条件的空间分异规律,将北方草地划分为7个功能区、25个亚区。该生态功能区划将为制定区域国土空间规划,科学布局重要生态系统保护和修复重大工程,统筹推进生态保护和修复工作提供重要的科技支撑。 相似文献
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A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
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《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
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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
14.
《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
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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
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Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
17.
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
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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
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Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
20.
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