首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   272篇
  免费   24篇
  国内免费   15篇
测绘学   33篇
大气科学   23篇
地球物理   6篇
地质学   78篇
海洋学   53篇
综合类   32篇
自然地理   86篇
  2023年   3篇
  2022年   6篇
  2021年   7篇
  2020年   4篇
  2019年   10篇
  2018年   9篇
  2017年   19篇
  2016年   16篇
  2015年   23篇
  2014年   21篇
  2013年   32篇
  2012年   18篇
  2011年   26篇
  2010年   25篇
  2009年   8篇
  2008年   10篇
  2007年   11篇
  2006年   19篇
  2005年   7篇
  2004年   9篇
  2003年   3篇
  2002年   5篇
  2001年   4篇
  2000年   2篇
  1999年   3篇
  1998年   4篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1991年   1篇
  1985年   2篇
  1983年   1篇
排序方式: 共有311条查询结果,搜索用时 734 毫秒
131.
This paper explains the ongoing conflict between Trinidad & Tobago and Barbados over the right to catch flying fish off the coast of Tobago. The aim of the paper is to present the different scenarios arising from the conflict and to determine the best outcome for managing the flying fish. The history and current situation of the conflict is presented. The possible outcomes are evaluated with a framework developed in the paper. It is concluded that a negotiated agreement between the two countries gives the best result. Future negotiations should focus on developing a limited access program like Individual Transferable Quotas.  相似文献   
132.
A principal challenge in developing any fishery management plan is the allocation of benefits and costs among participants in the fishery. This process is further complicated by imperfect information about future market demand and limited ability to predict the consequences of regulatory change. This paper offers a new approach to policymakers, using econometric analysis to simulate the potential impact of individual tradable quotas (ITQs) in a fishery. We compare the distribution of harvest across participants in the Atlantic Herring fishery under the current open access regime and under a potential ITQ regime, assuming two different levels of future demand. Our results show that production efficiency varies by vessel gear, home-port and relationship with buyers. Some of the predicted consequences of ITQs are: vessels from Massachusetts will gain share relative to those from Maine; trawlers will gain share relative to purse seine vessels; and independent vessels will lose share relative to vessels that are primarily contracted to specific processors or bait companies. These results will help policymakers in developing future management plans for the herring fishery. More generally, this analytical approach can help regulators in any fishery assess the potential impact of alternative policy changes under alternative future demand scenarios.  相似文献   
133.
Collective forest tenure reform and water rights system reform are two types of resource system reform initiated by the Chinese government since the implementation of the reform and opening policy of the 1980s. Forest tenure reform has been completed and water rights system reform is ongoing. This study analyzes key points and problems with collective forest tenure reform and summarizes four typical successful reform measures and lessons that will have implications for the developing water rights system: the collective forest-cutting quota system, collective forest tenure compensation, collective forest tenure confirmation, and collective forest tenure trading center. A flexible water permission index, compensation measures in water rights trade, water rights approval, and various forms of water rights trading platforms are proposed as reform measures. This study fills a gap in comparative studies between two important resource system reforms in China and provides a reference for further reform and development of water rights systems locally and abroad.  相似文献   
134.
对机构改革背景下空间规划体系构建的思考   总被引:1,自引:1,他引:0  
郝庆 《地理研究》2018,37(10):1938-1946
“建立空间规划体系”是自然资源部的一项重要职能,也是整合空间规划、保障空间治理机制有效运行的必然要求。在借鉴国外空间规划体系的基础上,按照适应中国政治体制和法律基础、适应未来空间开发和空间治理变化的需求,提出构建层层传导的空间规划体系确保国家重大战略部署得以落实;提出在微观尺度空间规划进行空间开发权与土地利用权的分配,作为实施空间用途管制的法律依据,保障地方多样化、灵活化的发展;通过构建“宏观政策性/指导性规划—中观衔接性规划—微观实施性规划”的空间规划体系,为国家建立和完善空间规划体系、提升空间治理能力提供参考。  相似文献   
135.
农村土地承包经营权确权是目前农村土地改革的一项重要工作,本文以甘肃镇原县农村土地承包经营权确权项目为例,采用带有POS系统推扫式数码航摄仪ADS80进行数字航空摄影测量,生产正射影像DOM,并结合全球定位连续运行基准站系统GSCORS实测进行界址点测量和地块图绘制,以及经权属调查后,基于GIS平台建立确权登记数据库,该技术极大地方便了土地承包经营权确权工作,明显地提高了工作效率。  相似文献   
136.
Successful adaptation to climate risks will depend on the outcomes of many coordinated and uncoordinated actions. Key will be ensuring public and private adaptations undertaken at a variety of scales do not undermine one another. To improve understandings of how adaptive responses accumulate, we investigate interactions between public and private efforts to mitigate flood hazards in the Deerfield River Watershed, located in Western Massachusetts, USA. Through interviews, we uncover the manner in which private adaptations, undertaken by landowners seeking to protect their land from flood impacts, are both determined in response to and have an effect on public adaptations seeking to address flood impacts across the watershed. Landowners respond to public adaptations based on their perceptions of the appropriateness of adaptive pathways including how they view the effectiveness of adaptive action and how the actions fit with the social contract. As a result, the interface between public and private adaptations takes various forms: commutable, attenuating, synergistic, or countervailing. Our findings underscore how, in areas with high geo-physical connectivity and where responsibility is dispersed across private and public entities, anticipating and responding to multiple interfaces between public and private adaptations is needed for public adaptations to achieve the best cumulative outcomes.  相似文献   
137.
Marine fisheries in Costa Rica have become characterized by overexploitation, ineffective centralized management and increased conflict among fishing sectors. Despite high economic and socio-cultural importance of small-scale fisheries, no formal mechanisms existed until recently to facilitate the participation of fishers in management. Marine Areas for Responsible Fishing (Áreas Marinas para la Pesca Responsable, AMPR) were legally recognized in 2009 as a co-management approach, enabling the designation of spatial management areas to be implemented collaboratively by artisanal fishers and government agencies. In this paper, we examine property and access relations shaping this emerging participatory management model using case studies primarily from the Gulf of Nicoya region. The policy demonstrably improves upon some aspects of management, for instance, by allowing artisanal fishers to determine gear restrictions within designated areas. However, the model lacks other attributes of more successful co-management scenarios, particularly exclusive access. The fugitive nature of resources further complicates property relations over these fisheries. The cases explored also illustrate broader institutional and systemic issues that preclude effective participatory management. Lessons from the region are used to propose significant shifts to the management of small-scale fisheries in Costa Rica.  相似文献   
138.
This paper offers a critical assessment of REDD+ in Nigeria through a political ecology perspective. Focusing on questions of property rights and resource access, it maps the discursive articulations and contestations through which carbon rights are being determined. It also shows how these articulations and contestations are linked to land and forest rights, and how they shape everyday access to the forest. Evidence from the Nigerian case suggests that factors that complicate rights and undermine access to resources for forest communities under REDD+ are immanent to the contested terrain constituted in part by REDD+ proposals, proponents’ discourses and practices geared towards securing the forest for REDD+. Efforts to secure property rights and guarantee the permanence of REDD+ forests align with economic, ecological and ideological aspirations of state and non-state actors to produce a regime of militarised protectionism. I demonstrate how, in addition to its material and symbolic facilitation of the emergent carbon forestry economy, militarised protectionism as a regime of exclusion also constitutes collateral political economies of ‘more-than-carbon’ forest resources (such as timber and non-timber forest products) which perpetuate capital accumulation by the elites. It is this kind of exclusion–accumulation dialectic, legitimised by carbon forestry claims that this paper describes as carbonised exclusion. The paper thus furthers debates on the political ecology of REDD+ and other carbon forestry projects, while productively engaging technocentric literature on REDD+ and property rights.  相似文献   
139.
Stigma and concern about public breastfeeding have been identified as contributing towards low breastfeeding rates in high-income countries. Despite this, very little research has examined public perceptions of breastfeeding. Among existing studies, lack of familiarity with breastfeeding, sexist views and hyper-sexualisation of the breast were identified alongside discomfort at viewing breastfeeding by strangers. During 2014, in the United Kingdom (UK), several cases of women being criticised for breastfeeding in public appeared in national newspapers. A Critical Discourse Analysis approach was used to theoretically frame analysis of 884 naturally occurring comments relating to a protest supporting women’s right to breastfeed in public from the UK’s most popular online news site, Mail Online. Findings are discussed in relation to mothers’ roles as citizens and sexual beings, with a particular focus on the visibility of breasts in public space. Women who breastfeed in public were viewed as unattractive, lazy, bad parents and lacking in self-respect. More specifically, women who breastfed in public were viewed as exhibitionist. This was contrasted with the desirability of breastfeeding within the home, which was seen as an appropriate way to feed an infant. The undesirability of public breastfeeding was inherently linked to sexuality, with breastfeeding women viewed as sexual aggressors (“flashers”) or inviting sexual contact from men. It is argued that these views originate in unequal gender relationships in society and the framing of breasts as sexual rather than nurturing. These discourses are played out in public space in which mothers are marginalised in a patriarchal society.  相似文献   
140.
“3S”技术在农村土地承包经营权确权登记中的应用   总被引:1,自引:0,他引:1  
"3S"技术在农村土地确权登记工作中的应用,有助于地籍信息的获取、宗地位置的表达、土地面积的测量以及土地权属信息的核查,提高了工作效率及数据的精确性。本文以青海省海东市互助土族自治县农村土地承包经营权确权登记试点项目为例,阐述"3S"技术在土地确权登记工作中的具体应用。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号