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三江源地区的生态危机与保护建设战略探索 总被引：2，自引：0，他引：2
三江源地区独特的生态环境造就了世界上高海拔地区独一无二的大面积湿地生态系统,长江、黄河、澜沧江三大河流得以同源于此。随着气候的变化和人类活动的日趋频繁,使源区生态环境的恶化不断加剧,人口、资源、环境与发展之间的矛盾日益突出,保护生态环境与自然资源已刻不容缓。 相似文献
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青海省清洁能源发电潜力及价值分析 总被引：2，自引：0，他引：2
随着科技进步,清洁能源的开发利用成为缓解资源短缺、改善生态环境的重要途径,对清洁能源潜力进行量化评估,有助于有关部门制定合理的开发利用决策。本文基于模型模拟和空间分析等方法,对青海省水电势能、太阳能、风能、生物质能、地热能5种主要清洁能源的发电潜力及价值进行评估,得到了青海省主要清洁能源发电潜力的时空分布格局和数量统计特征。结果表明：①从时间上看,2000—2018年清洁能源发电潜力呈逐年增加趋势,空间分布格局变化不大,发电潜力较稳定。从空间上看,青海省西部清洁能源发电潜力相对较高,东部较低;州（市）尺度上,玉树州、海西州处于清洁能源发电潜力高值区,西宁市处于低值区;生态功能区尺度上,三江源地区处于清洁能源发电潜力高值区,祁连山地区处于低值区。②从清洁能源结构来看,青海省水电资源潜力最为丰富,2000—2018年水电势能平均发电潜力达到2338.41亿kW·h,其次是生物质能、地热能、太阳能和风能,且在实际应用中清洁能源在能源消费中的比重逐渐增大。③2000—2018年青海省清洁能源潜力平均价值为1887.75亿元,未来可获得的清洁能源的经济价值将随着中国碳市场的发展和清洁能源开发利用强度的增大而逐渐增长。本文为青海省相关部门了解省内清洁能源的现状和未来开发利用前景,制定清洁能源开发利用政策提供了重要依据。 相似文献
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西藏丁青县1961—2015年气温变化特征分析 总被引：1，自引：0，他引：1
文章采用丁青县1961~2015年气温资料,运用气候倾向率、M-K趋势检验和突变分析、Morlet小波变换等方法对丁青县气温年、季变化特征进行分析,结果表明:丁青县平均气温、最高气温和最低气温均呈显著的上升趋势,气候倾向率分别为0.246℃/10a、0.242℃/10a和0.275℃/10a,升温率小于青藏高原地区,高于全国平均升温率。无论是平均气温、最高气温还是最低气温,四季均表现为增温趋势,以冬季增温幅度最大。平均气温、最高气温和最低气温的升高均为突变现象,突变点分别在1995年、2002年和1994年左右。气温变化存在明显的周期,且无论较长周期还是较短周期的变化都处于偏暖期,且在未来一定时期内呈向较暖趋势发展的走向。 相似文献
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本文分析、总结出三江(黄河、长江、澜沧江)源地区生态环境恶化的直接原因是气温持续升高，汛期降水减幅明显，以及不顾生态的人为活动。同时，从空中水资源含量、降水天气系统、大气凝结核等方面论述了开发利用三江源地区空中水资源的可行性。1997～2003年的人工增雨作业实践证明，三江源地区空中水资源是可以利用的。 相似文献
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黄河源区是黄河流域最重要的水源地和产流区,贡献了超过全流域37%的产流量,对流域中下游地区的水资源安全、粮食生产和生态环境有决定性的意义。明晰黄河源区近60年来的气候水文和近30年来的植被覆盖特别是草地退化的变化特征,不仅是深入理解黄河源区水文循环机理的前提,也是准确把握源区及中下游水资源状况和生态环境的关键,更是贯彻习近平总书记"黄河流域生态保护和高质量发展"要求的核心问题。从气候角度看,黄河源区自1951年以来经历了显著的暖湿化过程,20世纪90年代有所回落。但从2000年以来,气温和降水以更快的速度增大,进而引发了冰川积雪消融加剧、蒸散发增加和冻土层退缩等一系列后果。然而,由于各个过程中水分损耗的加剧以及人类活动的影响,这种增湿并不能转换为有效的水资源,黄河源区的观测和天然河川径流量均呈现出减少的趋势。而不断退化的草地则使得区域水分涵养能力不断降低,生态环境不断恶化。面对黄河源区严峻的水资源和生态环境挑战,除了继续深入研究黄河源区水文循环机理外,建议应做到:(1)将生态环境保护放在首位;(2)水资源的有序开发利用;(3)社会生产与自然环境的和谐共存;(4)从战略高度贯彻实施有序适应气候变化。 相似文献
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《资源科学》2019,(1)
气温的差异是造成自然景观和生态环境差异的主要因素之一。本研究采用全国一级流域735个气象站点1951—2013年气温资料,利用相对差分法、Hurst指数等方法对年气温的时空变化特征进行分析。结果表明:全国年气温总体呈显著升高趋势,但长江区中部年气温变化不显著。全国、辽河、海河、淮河、黄河、长江、西南诸河、东南诸河和珠江区均存在区域年气温的最佳代表性气象站点,分别为铁干里克、彰武、乐亭、菏泽、海源、井冈山、加查、武夷山市和柳州。代表性气象站点的年气温可以用以快速评估流域年气温均值的变化特征。全国一级流域年气温变化的主周期大致为25～28年。近20～30年是研究期内的偏暖期,Hurst指数分析表明在未来相当长一段时期内,全国绝大部分地区的气温会呈现为升高趋势。"哈尔滨-北京-石家庄-西安-重庆-贵阳"连线附近年气温与年降水量主要呈(极)显著负相关关系,该连线接近于"胡焕庸线","胡焕庸线"附近的气候研究对中国生态环境保护和"一带一路"倡议具有重要意义。 相似文献
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近40年浙江省气候变化的分析 总被引：2，自引：0，他引：2
利用浙江省9个站点近40年(1951～1990)的逐月气温及降水资料,对近40年浙江省的气候变化状况作了初步分析.结果表明,近40年我省气温的变化趋势为降温→升温→再降温→再升温.第一次升温幅度大于第二次,第一次降温幅度不及第二次.降水的变化趋势为减少→增加,增幅不及减幅.在东部沿海,逐年气候特征以冷干和暖温较为多见,而其它地区则多出现暖干和冷湿气候. 相似文献
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近47年三江源雨季降水时空分布特征 总被引：2，自引：0，他引：2
利用三江源(黄河、长江、澜沧江)地区13个气象站1961～2007年雨季(6～9月)降水资料,分析了三江源地区雨季降水的变化特征.结果表明:近47年来三江源地区雨季降水量呈减少趋势,减少幅度为1.9mm/10a.EOF分解显示,第一模态表现为降水空间变化的全区一致性,第二模态表现为西南部与东北部的反相,第三模态表现为西北部与东南部的反相.将全区分为东部、南部、西部、北部四个地区,用小波变换分析的结果是,东部和西部的突变点相接近,分别为1987、1988年,但旱涝期正好相反:南部为先涝后旱,突变点在20014年;北部为先旱后涝,突变点在1966年,南、北两地区的干旱期均长于偏涝期. 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
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《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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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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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
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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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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
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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