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黄淮海平原农地流转空间分布与格局特征 总被引：1，自引：0，他引：1
农地流转已经成为影响中国农业发展的重要因素之一,分析农地流转空间格局特征对中国农业的转型发展尤为重要。本文以黄淮海平原农户调查数据为基础,引入ELL模型对黄淮海平原农地流转抽样数据进行了空间推演,获得该地区县域尺度农地流转方向和规模的空间格局参数,进而通过局部空间自相关分析描述农地流转表征指标在县域尺度上的集聚特征。研究表明:①黄淮海平原县域农地转入规模在440.79~1379.86hm2,呈现出由西向东递增的趋势;农地转出规模在908.61~2745.29hm2,表现出由西北向东南递增的特征;②农地转入和转出的Moran’s Ii值分别为0.78和0.89,反映出黄淮海平原农地转入和转出规模在空间上正相关（HH集聚和LL集聚）,且相关系数较高;③在95%的置信度下,农地转入HH集聚区、LL集聚区县域单元数量占比分别为16.67%和20.61%;农地转出HH集聚区、LL集聚区县域单元数量占比分别为19.08%和26.32%;HH集聚的县域是黄淮海平原农地流转的核心区,有着较强的正向效应,LL集聚的县域在空间分布上较集中、稳定,对周边县域有负向影响。该研究揭示的黄淮海平原农地流转空间分布信息或规律,可以为农地流转空间格局优化和相关的管理政策制定提供参考。 相似文献
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区域性创新具有明显的空间关联性和过程动态性,进而带动创新空间格局的演化。通过运用空间计量分析工具,对2005-2015年我国区域创新产出空间格局演化特征及影响因素进行了实证分析。初步研究结果表明：第一,我国区域创新产出呈现出空间集聚的阶段性特征,2011年成为空间集聚态势转型的重要节点;第二,创新集聚程度呈现东中西地带差异;第三,区域创新产出呈现出一定的空间扩张趋势,但区域拉动力不足;第四,区域创新要素投入对区域创新产出影响存在区域差异,区域创新市场需求及区域创新环境对整体区域创新产出具有正面影响。上述研究结果对于我国区域创新政策调整具有一定参考价值。 相似文献
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近年来,区域创新得到了广泛的关注,然而大部分对区域创新的研究集中在宏观的国家或省级区域层面,少有学者关注较小的空间尺度如县域创新。以浙江省71个县域单位为研究对象,运用极差分析、洛伦兹曲线分析以及探索性空间数据分析(ESDA)等方法分析了2003—2012年浙江省县域创新产出水平的空间差异及其时空演变。研究发现,区域创新行为的空间相关性在县域层面显著地高于省域水平,考察期内县域创新产出基尼系数有一定程度降低,但不均衡程度仍然很高:知识溢出效应对周边地区的促进作用存在其空间局限性,并且能否有效吸收这种技术知识溢出也将限制这种效应,决策者除了要重视创新要素投入外,还应更多的关注知识的空间溢出效应。 相似文献
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文章评估了浙江省各县域科技创新活动的发展水平,分析了其空间聚集效应。在建立科技创新活动多指标综合评价体系的基础上,通过主成分分析法评价了浙江省90个县域2009~2012年的科技创新活动发展水平,并通过Moran’s I指数进一步分析了浙江全省以及各区县间的科技创新活动的空间聚集效应。结果表明:浙江省科技创新活动发展存在较明显的"东北崛起,西南塌陷"的空间格局,浙东北地区为科技创新活动发达聚集区,而浙西南为滞后聚集区。在时序上,区域创新活动水平总体呈稳定状态。创新活动发达区与滞后区的主要差距在于创新组织上。结论对于促进县域空间尺度的科技创新研究和实践具有一定的指导意义。 相似文献
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采用熵权法测度2015—2020年中国30个省份制造业高质量发展水平,并采用泰尔指数和莫兰指数分析区域差异和空间集聚特征。研究发现：(1)整体上看,制造业高质量发展呈长期向好态势,但发展水平依旧不高;分维度来看,增长规模和产品质量处于较低水平,且呈波动下降趋势,产业结构优化升级、两化融合、创新驱动、开放发展呈不断上升态势,而绿色发展则呈波动上升趋势;从区域分析来看,东部制造业高质量发展水平呈稳步向上态势,中部总体呈不断上升状态,西部呈上升态势,但增速较慢,东北则出现停滞。(2)区域间差距在不断扩大,直接原因是地区内差异的不断增加,间接原因则是区域划分方式不同和产业转移。(3)各省市区制造业高质量发展水平呈现显著的空间正相关性,但其空间集聚性在不断减弱,未来中西部地区需充分挖掘资源禀赋优势,有序承接产业转移,东部地区则需进一步强化对外协同作用,引导内陆省份有序发展。 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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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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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
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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
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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