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1.
基于现代农业发展的丘陵山区农用地整治分区与发展策略——以重庆市云阳县为例 总被引：3，自引：0，他引：3
农用地整治分区以及相应的差异化整治策略一直都是学界关注的热点,但多目标导向和局域约束条件的提炼仍稍显薄弱。本文尝试将丘陵山区现代农业发展这一社会选择目标与农用地整治分区这一既定目标相结合,提出多元化整治目标函数的研究范式。这一范式的形成不同于之前学者运用案例比较和收益—成本分析等方法提出的分区目标,而是运用机制设计理论讨论现代农业发展与整治分区相互关系和作用渠道的基础上得出的综合目标函数。在此理论框架下,本文以重庆市云阳县为实例,基于土地利用规模化、经营现代化和生态景观管护3个主要变量,24个操作指标,运用一般均衡和动态优化的思路,以最大化社会总剩余为目标,提炼各整治类型区(优先整治区、适度整治区、优化调整区、重点整治区、限制整治区)现代农业发展的约束条件,进而提出不同整治类型区的发展策略,据此提出的发展策略与研究地区未来的土地利用规划和产业发展规划更为契合。 相似文献
2.
土地管理之利器——土地利用总体规划 总被引：1，自引：0，他引：1
文章主要从土地利用总体规划是土地用途管制的依据,充分确立土地利用规划的法定地位,完善规划体系,抓好横向、纵向规划,建立"规划-许可-计划"的土地用途分区和土地指标控制相结合的管理体系,强化土地利用规划的实施管理以及改进土地利用规划编制的方式方法等5个方面进行了. 相似文献
3.
基于生态风险空间差异的土地整治投入优先序研究 总被引：1，自引：0，他引：1
近年来,中国各地投入了大量资金实施土地整治项目,取得了显著成效,但在安排项目及其资金投入的先后顺序方面,缺乏科学的依据和标准,已成为土地整治中亟待解决的问题。本文以甘肃省华池县为例,在“十三五”土地整治规划（2016—2020年）确定的整治潜力的基础上,运用相对风险模型（RRM模型）,对华池县15个乡镇的生态风险空间差异进行评价,确定土地整治投入优先序。结果显示：①华池县土地整治生态风险划分为低风险区、中风险区、较高风险区、高风险区4个等级;②土地整治投入优先序划分为整治优先投入区、一般投入区、投入紧缩区、限制投入区,并从管控风险的角度提出各区域未来土地整治的重点方向和注意问题。研究表明：运用相对风险模型（RRM模型）评价生态风险更符合土地整治工程建设实际,在此基础上确定的土地整治优先序符合西部生态环境脆弱区实际情况,在确定土地整治资金投入顺序中是一种较好的方法。 相似文献
4.
《资源科学》2017,(2)
耕地整治优先度和模式的科学合理性对土地整治工作有重要意义。本文系统讨论了丘陵沟壑区耕地整治优先度的原则,从自然资源条件、基础设施与工程施工条件、立地条件三方面构建黄土丘陵沟壑区耕地综合条件评价指标体系,以甘肃天水市麦积区为例,运用综合评价系数法和GIS标准分类法确定耕地整治优先度,并分析耕地整治模式。结果表明:(1)麦积区耕地整治优先度评价结果表明所构建的黄土丘陵沟壑区耕地综合条件评价体系具有一定的可行性;(2)根据耕地地块综合条件系数评价结果,划分麦积区耕地整治优先度为优先、一般和限制整治区;(3)运用因素组合法,将麦积区耕地整治模式划分为:"土坎梯地+经济林"、农田水利建设及优化和路林网密织三种模式。 相似文献
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6.
生态环境建设的内涵与配置 总被引：2，自引：1，他引：2
该文从生态环境建设的概念入手,深入分析了生态环境建设的内涵.指出,生态环境建设的实质是水资源、土地资源、气候资源、生物资源等再生自然资源的保护、改良与合理利用.在<全国生态环境建设规划>划分的8个生态环境建设类型区的基础上,提出了以流域为单元进行生态环境建设分区配置的必要性.并以黄河流域上中游为例,重点探讨了其生态环境建设分区的方法与成果.作者采用综合的生态经济指标,以县为单元,将西北地区黄河流域划分为6个生态环境建设区,即风沙区、黄土丘陵沟壑区、黄土高塬沟壑区、沿河阶地与平原区、土石山区、河源区.在分区的基础上,确定了各区生态环境建设的生态经济目标及相应的措施配置模式.针对生态环境建设中存在的问题,提出了对策建议以流域为单元进行生态环境建设分区;因地制宜建设主攻方向;积极稳步推进"退耕还林还草";加大投资力度,拓宽投资渠道;加强法制建设,把预防监督放在首位;充分满足生态环境建设的需水要求. 相似文献
7.
中国西部生态—经济区的主要特征与症结 总被引：4，自引：0，他引：4
本文是根据西部地区自然、社会、经济的地域分布规律,选取包括自然条件如降水、气温、地形、光温生产力、初级生产力与环境人口负荷评估状况,水资源情况,土地利用情况,生态景观退化情况,城镇化与经济发展情况等,划分出三级西部生态-经济区划的分区.根据西部生态经济区划的东部、西北和青藏高原三大地带,以及28个三级生态-经济区的具体情况,具体阐述了各生态-经济区的主要特征与症结,分别从各主要分区的自然背景、社会发展和经济综合指数分析西部各生态-经济区的主要特征与存在的问题.依据区划中的地带性特征,针对不同的典型区,提出了相应的对策和建议. 相似文献
8.
该文从生态环境建设的概念入手,深入分析了生态环境建设的内涵。指出,生态环境建设的实质是水资源、土地资源、气候资源、生物资源等再生自然资源的保护、改良与合理利用。在《全国生态环境建设规划》划分的8个生态环境建设类型区的基础上,提出了以流域为单元进行生态环境建设分区配置的必要性。并以黄河流域上中游为例,重点探讨了其生态环境建设分区的方法与成果。作者采用综合的生态经济指标,以县为单元,将西北地区黄河流域划分为6个生态环境建设区,即：风沙区、黄土丘陵沟壑区、黄土高塬沟壑区、沿河阶地与平原区、土石山区、河源区。在分区的基础上,确定了各区生态环境建设的生态经济目标及相应的措施配置模式。针对生态环境建设中存在的问题,提出了对策建议：以流域为单元进行生态环境建设分区;因地制宜建设主攻方向;积极稳步推进“退耕还林还草”;加大投资力度,拓宽投资渠道;加强法制建设,把预防监督放在首位;充分满足生态环境建设的需水要求。 相似文献
9.
近年来,中国各地进行了大量的土地整治工作,但如何合理安排土地整治项目,实现土地整治资金使用效率的最大化已成为亟待解决的问题。本文基于数据包络模型,对湖北省85个县（市、区）土地整治绩效的空间差异进行评价,然后运用生态系统服务价值相关理论测算土地整治生态潜力,并对数量、质量、生态潜力进行聚类,得出综合潜力,最后对土地整治绩效水平分级图与综合潜力分级图进行空间叠加,确定土地整治投入优先序。结果显示：①湖北省土地整治绩效水平相对较高,其中综合效率有效的地区有29个,技术效率有效的地区有36个,规模效率有效的地区有29个,三者均值分别为0.8607,0.8931,0.9600。从空间分布上来看：综合效率均值、技术效率均值均呈现中间高两头低的态势,而规模效率则表现为中间低两头高;②土地整治综合潜力可以划分成五个潜力级别区;③全省可划分成16个土地整治优先投入区、25个次优先投入区、20个一般投入区、24个投入紧缩区,并结合各区域特点,指出未来土地整治的重点方向。研究为确定新一轮土地整治资金投入的方向、提高土地整治资金使用效率,提供基础性的理论依据。 相似文献
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以马村区为例,在明确农用地整治潜力内涵的基础上,从数量、质量两方面对全区农用地整治增加耕地潜力进行了系统的测算和评价,分析了其农用地整治潜力的空间分布特征;选取新增耕地系数、新增耕地面积、耕地质量提高潜力作为评价因素,将马村区农用地整治潜力划分为Ⅰ、Ⅱ、Ⅲ3个等级,为马村区土地整治规划工作提供了依据。 相似文献
11.
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
12.
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
13.
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
14.
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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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
16.
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
17.
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
18.
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
19.
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
20.
《中国科学院院刊(英文版)》2014,(3)
<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence 相似文献