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1.
量化长江经济带水资源消耗时空差异的驱动效应,对双控行动的贯彻实施具有重要意义。本文采用LMDI方法,将用水量的时空差异分解为经济规模效应、产业结构效应和技术进步效应,用水强度的时空差异分解为产业结构效应和技术进步效应。结果显示：技术进步、产业结构调整是抑制用水量上升和促进用水强度下降的主次因素,而经济增长始终推动用水量上升;三次产业用水效率普遍提高和第一产业比重下降,有力促进了用水量和用水强度下降;与重庆相比,其他省份产业用水强度始终较大,尤其是第一、二产业,不利于用水量空间差异的缩小,长江三角洲省份产业结构更加高级缩小了用水量空间差异;与上海相比,其他省份第三产业用水强度始终较大和产业结构低级扩大了用水强度空间差异;水资源消耗时空差异之间存在相互转换的关系。因此,用水量控制应该围绕提高用水效率和优化产业结构,还需要辅助于经济、制度等手段,同时,根据三次产业特征差异而有所侧重;各省份选定参照对象后,依据空间差异驱动效应情况,提出适用的节水对策。 相似文献
2.
量化长三角地区用水量时空差异的驱动效应,对该地区节水型社会建设具有重要的意义。本文采用LMDI方法,将2000—2015年长三角用水量时空差异的驱动效应分解为强度效应、结构效应、收入效应和人口效应。研究发现,从时间角度看,产业用水强度下降和产业结构调整是用水量下降的驱动因素,尤其是前者,除上海第一产业外,长三角三次产业用水效率普遍提高;产业结构调整促进用水量下降的作用主要来源于第一产业;经济增长和人口增加促进了用水量增加。从空间角度看,用水量差异及其驱动效应与参考对象的选择密切相关;浙江第一、二产业用水效率提高促进用水量下降具有明显优势,而上海在第三产业上具有优势;上海产业结构更加高级化,而江苏和浙江的第一、二产业比重较大;江苏和浙江要努力控制人口规模,也是缩小用水量空间差异的有效途径。因此,长三角要采取有针对性、差别化的节水政策措施减少用水量,可以从技术进步、产业结构调整以及人口控制方面具体考虑,经济增长是社会前进的动力,反而会增加用水需求。 相似文献
3.
基于面板VAR模型的新疆农业用水与农业经济增长的互动效应研究 总被引：5，自引：0，他引：5
新时期以"绿洲灌溉农业"为特征的新疆各地区农业的快速发展与农业用水比重必须下降的现实,使得探讨两者之间的相互关系尤为重要。本文基于1997-2011年新疆15个地州(市)面板数据,建立了农业用水量与农业经济增长的面板VAR模型,考察农业用水与农业经济增长的互动效应。研究结果表明:1新疆三个区域的农业用水和农业经济增长之间存在长期协整关系;2北、东、南疆的农业用水对农业经济增长的推动效应有明显差异,其中北疆地区农业经济增长效应最大,其次为东疆,再次为南疆;3农业经济增长对农业用水量的变化产生的效应南疆最明显,其次为北疆,东疆用水结构较为稳定,农业用水量变动最小。因此,依据各地农业用水与农业增长的短期与中长期因果关系建立科学灌溉制度与水资源政策,依靠节水技术,才能有效提高农业综合效益。 相似文献
4.
最终产品本地用水指支持最终产品生产所需的本地水资源,该用水指标能够反映最终消费和产品供应链对当地水资源的影响,因而开始被学者所关注。本文以天津市为研究区,采用环境投入产出分析技术核算天津市的最终产品本地用水量,并用结构分解模型对其变化情况进行驱动力分析,进而探究了社会经济层面上的驱动机理。结果表明：2002-2012年间天津市最终产品本地用水量增加了6%（1.1亿m3）。人均最终消费效应是其增加的主要驱动因素,直接用水强度效应和最终消费部门效应是抑制其增加的主要因素;从产业部门来看,农业部门的最终产品本地用水量最大,但工业规模的扩大是导致最终产品本地用水量增加的主要原因。天津市可以通过减少出口高用水强度产品、提高出口产业用水效率、提倡本地居民改变消费结构和将最终产品本地用水和水足迹等指标融入企业绿色核算体系等方式减少天津市本地用水,缓解水资源短缺压力。 相似文献
5.
城镇化进程中居民消费对水资源消耗的影响效应研究 总被引：1，自引：0，他引：1
构建向量形式的Kaya扩展模型,运用LMDI方法将用水总量分解为人口规模、人口城镇化、居民消费、消费抑制因子、技术进步和产业结构调整6种效应。研究表明:用水总量的增长主要来自于居民消费的贡献,尤其是城镇居民消费引起的间接耗水的增长;人口规模和人口城镇化对用水总量的增长具有持续的正向作用,且人口城镇化的驱动力要强于人口规模;消费抑制因子对用水总量的影响经历了由正到负的过程,与用水总量之间存在反向变动的逻辑关系;技术进步与产业结构调整对用水总量的增长呈现出持续的抑制效应,但是变动幅度较小,凸显出当前我国技术进步和产业结构调整在节水方面的乏力。虽然居民消费极大地推动了用水量的增长,但是由于居民消费在整体国民经济中具有用水强度的比较优势,因此提高居民消费水平并不违背水资源的节约目标,同时施以节水技术创新和产业结构改善等手段,能够实现水资源的可持续发展。 相似文献
6.
中国结构升级、技术进步与水资源消耗——基于改进的LMDI方法 总被引：3，自引：0，他引：3
针对水资源消耗强度问题,本文基于改进的LMDI方法研究1997-2011年我国水资源消耗强度变化的影响因素。我们发现,总效应与强度效应具有相似的变化趋势,强度效应下降及反转是总效应下降及反转的主要原因,产业结构效应未促进用水强度下降;利用完全模型得到,各省份用水效率普遍提高,主要由于技术进步,东部发达地区是用水强度下降的主要推动因素,产业结构效应并未推动总效应下降,区域结构效应对总效应的影响较弱;利用简化模型得到,总效应下降幅度较大的省份集中于西部地区,产业结构效应与强度效应对总效应的影响与完全模型一致,东部地区产业结构效应促进总效应下降的效果好于中西部地区;改进的LMDI方法符合残差检验和时间反演检验。因此,各省份发展经济的同时,需要关注技术创新,尤其中西部地区;加快产业结构调整,也是提高用水效率的重要途径;加强发达地区对欠发达地区的支持,缩小区域社会经济差距。 相似文献
7.
基于海洋资源消耗强度内涵,测度中国沿海省区1996—2015年海洋资源消耗强度,揭示其时空演化特征,运用改进的对数均值迪式指数分解法（LMDI）建立因素分解模型,分析中国海洋资源消耗强度变动的因素贡献并进行差异比较。结果表明：①1996—2015年,中国海洋资源消耗强度总体呈先上升后稳步下降的态势,第一产业资源消耗强度平稳下降,第二、三产业资源消耗强度与中国海洋资源消耗强度变动趋势基本同步;空间格局演化上,海洋资源消耗中高强度省区逐渐减少,低强度省区逐渐增多,区域差异逐步缩小;②技术进步效应、产业结构效应和区域规模效应对我国海洋资源消耗强度下降的贡献率分别为78.224%、18.334%和3.442%;沿海各省区的因素分解效应差异显著,其中福建以技术进步效应为主,浙江、山东和海南以技术进步效应和区域规模效应为主,天津、河北和江苏以技术进步效应和产业结构效应为主,辽宁、上海、广东和广西则是技术进步效应、产业结构效应和区域规模效应共同推动海洋资源消耗强度下降;③从海洋三次产业来看,技术进步效应在第二产业内部贡献最大,累计占比为77.118%;产业结构效应在第一产业内部贡献最大,累计占比为314.547%;区域规模效应在三次产业内部无明显差异。各省区推行海洋三次产业资源集约利用技术或措施时应有所区别和侧重。 相似文献
8.
在干旱半干旱地区,农业部门用水量大,但利用率不高,所以发展节水灌溉成为缓解水资源稀缺的可能路径。但是在节水灌溉技术提高的条件下,如果实际节水效果达不到预期,就会出现“灌溉用水反弹效应”。基于此,本文从理论上构建了灌溉用水反弹效应的衡量方法,然后利用LMDI分解法将灌溉用水反弹效应分解为气候效应、单产效应、结构效应、面积效应和灌溉效应,并利用西北五省（区）2005—2016年的数据,在效应测算和分解的基础上分析了其驱动因素及区域差异。结果发现：①西北五省（区）整体的反弹效应高达340.00%,即新增用水量达到了预期节水量的3.4倍,其中甘肃、宁夏、青海、陕西和新疆的灌溉用水反弹效应分别为374.97%、55.10%、117.46%、434.51%和384.32%;②单位面积产量增长和种植面积扩大始终是促进西北整体和各省（区）灌溉用水反弹效应上升的驱动因素;③西北整体灌溉用水反弹效应上升的主导因素为单位面积产量增长,但各省（区）存在区域差异,其中甘肃、宁夏和陕西为单位面积产量增长,青海为气候变化,新疆为种植面积扩大。所以,为缓解旱区农业灌溉用水反弹效应,在整体策略上,不能追求单产的最大化,而应适当采取亏缺灌溉,并合理规划灌溉农业规模;在局部策略上,要实行差异化的区域政策,因地制宜。 相似文献
9.
黄河流域水资源供需矛盾突出,在有限的水资源条件下,亟需开展水资源需求管理,以保障社会经济可持续发展。本文以二级流域为基本单元,采用对数均值迪氏指数方法分析2003—2015年黄河流域用水量的时空演变特征,揭示流域用水时空变化的主要影响因素。结果显示：①黄河流域用水量占比全国用水量8.0%~9.3%,年用水总量呈现上升趋势,而人均用水量则呈下降趋势。②各二级流域用水量随时间变化的主导因素不一致,人口与人均GDP增长为用水量增加的主导因素,用水强度降低与产业结构升级能起到抑制用水量增长的作用。黄河二级流域人均用水量空间差异显著,用水强度对人均用水量空间差异的影响最显著,各因素对二级流域人均用水量空间差异的影响逐年减小。研究结果可为黄河流域水资源需求管理提供科学依据。 相似文献
10.
基于经济学中的边际思想,运用全分解模型计算出1997年-2007年中国以及31个地区(台湾、香港和澳门除外)产业用水的规模边际、技术边际与结构边际,分析了中国产业用水边际效应的时空分异规律;通过构建产业用水增长质量指数,分析了中国产业用水增长质量的时间分异特征,运用Gini系数、Theil指数分析其空间分异特征。结果表明:研究期内,中国产业用水增长质量在总体和局部都呈现提升的态势,但提升速度存在明显差异,产业用水增长质量总体差异在逐年增大,在总体差异的组成中,东部、中部、西部地区间和东部地区内部差异贡献比例较大。导致中国产业用水增长质量指数存在差异的最重要因素是各地区经济发展水平的不同。为此,平衡经济发展,适当加大中西部地区水资源利用与管理投资力度,是全面提升产业用水增长质量,缩小地区差异的关键所在。 相似文献
11.
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
12.
《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
13.
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
15.
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
16.
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
17.
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
18.
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
19.
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