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   74篇
  免费   3篇
  国内免费   3篇
测绘学   15篇
大气科学   13篇
地球物理   6篇
地质学   23篇
海洋学   14篇
天文学   3篇
综合类   1篇
自然地理   5篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2017年   2篇
  2016年   6篇
  2015年   3篇
  2014年   7篇
  2013年   2篇
  2012年   4篇
  2011年   11篇
  2010年   3篇
  2009年   6篇
  2008年   6篇
  2007年   3篇
  2006年   6篇
  2005年   4篇
  2004年   2篇
  2003年   2篇
  2002年   2篇
  2001年   3篇
  2000年   2篇
  1997年   1篇
  1995年   1篇
排序方式: 共有80条查询结果,搜索用时 15 毫秒
31.
The Kimberley coast in Australia's far north-west is the traditional country and home of a number of Indigenous groups and hosts some of the country's richest cultural heritage, most spectacular rock art, scenery and wildlife, making it an attractive tourism destination. A growing expedition cruise industry provides the main means of visitor access to remote coastal sites and offers excursions to shore-based attractions in what are mostly Aboriginal Reserve lands. In light of concerns about environmental and cultural site impacts resulting from increasing visitor numbers, this study examined biophysical site impacts along access trails to shore-based attractions and used qualitative methods to ascertain cultural impacts. The synthesis of the findings highlights that cultural concerns arising from visitor access without having sought traditional owner consent for such access, combined with a lack of traditional owner involvement in the planning, management or running of visitor activities, overshadow currently low environmental impacts of onshore expedition cruise activities. To overcome the continuing impasse regarding the issue of unsanctioned visitor access, the Kimberley urgently needs a coordinated approach by key stakeholders and the traditional owners which recognises and acknowledges the historical context. Such a process would facilitate tourism activities to become culturally sustainable.  相似文献   
32.
The imposition of exclusive statutory real property rights in or near pastoralists’ areas and their migration corridors permanently excludes and extinguishes pastoralist rights to mobility and access to required resources. Seasonal interactions with non-pastoralist land use actors often occur during pastoralist migrations between rangelands and highlands or dry season grazing areas. In an embedded case study in Northern Kenya, in which interviews based on semi-structured questionnaires were held with pastoralists and non-pastoralists, we investigated how non-pastoralist land use actors manage encounters with migrating pastoralists within the context of the Land Administration system. We found that the majority of non-pastoralist land use actors encounter migrating pastoralists during distinct periods. Most never allow herders access to privately owned land. A small proportion allow access and make temporary verbal or written access agreements containing provisions on grazing fees, grazing regulations and rules to protect private property. The majority of non-pastoralists are unwilling to have access arrangements formalized. We argue that land rights adjudication should identify and confer all existing land rights to all users to avoid obstruction or renegotiation for access, and recommend the inclusion of pastoralists’ access rights as real property rights in the Land Administration system.  相似文献   
33.
Tuna has made a significant contribution to Indonesian and world fisheries. Indonesian tuna fisheries were introduced from Japan, Taiwan and Korea. Longline fishing was introduced in 1962, and purse seine gear was first used in 1974. Many foreign vessels have reflagged to the Indonesian flag. The Indonesian government developed its own tuna fisheries and closed the chartering program in 2006. Through these efforts, Indonesia became the number one tuna production country in 2004 and has further targeted an increase in marine capture fisheries catch of 0.5%/year from 2010 to 2014. Tuna resources remain under pressure globally. The tuna regional fisheries management organizations attempt to manage tuna fisheries by strengthening conservation of stocks. To enhance international cooperation, Indonesia ratified the 1982 Convention on the Law of the Sea in 1985 and the Agreement for the Implementation of the Provisions of the United Nations Convention on the Law of the Sea of 10 December 1982 relating to Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks in 2005 and became a member of Indian Ocean Tuna Commission and Commission for the Conservation of Southern Bluefin Tuna and a cooperating non-member of Western and Central Pacific Fisheries Commission in the 2000s. Consequently, Indonesia adopted domestic regulations to comply with management measures. For future sustainable development, Indonesia needs to build its capacity, improve its compliance with the tuna RFMOs’ conservation and management measures, strengthen data collection, develop its products to increase their quality and diversification, and enhance its international cooperation.  相似文献   
34.
Landings statistics of the Peruvian anchovy fishery show that the fishery went through a phase of explosive and uncontrolled growth from its establishment in the mid-fifties until its collapse in 1972. After the collapse, a second phase from 1973 to 1984 was characterized by unfavorable warm ocean conditions and low catches. A third phase, from 1984 to the present, with propitious ocean-environmental conditions and modern governance, can be further divided into a controlled growth period (1985-1994) and a sustainable landings' period (1995 to present). The most recent period of the third phase has enabled the fishery to maintain its catches and be labeled as one of the most sustainable fisheries worldwide. This article highlights the evolution of the legal system that provides for the current sustainable landings and governance of this fishery. Results show that General Fisheries Acts were enacted independently of failures to sustain anchovy landings. The three Peruvian Fisheries Acts were a reflection of broader national socio-political changes and were enacted mainly to define the role of the state and private investment and to delimit foreign involvement in the fishery industry. By contrast, the enactment of secondary legislation to control quotas and fishing seasons increased as the fishery moved towards stable landings. During this phase, enacted secondary legislation showed also a clear peak during strong positive sea surface anomalies driven by the El Niño Southern Oscillation (ENSO) 1997-1998, providing evidence of rapid adaptive management. The role of Fisheries Acts in defining access rights at the national level from a multilevel governance approach is discussed and further key elements that contributed to the transition towards sustainability are suggested.  相似文献   
35.
通过农牧网站专业气象服务系统中的用户登录模块的制作,介绍了利用ASP技术实现信息的更新、浏览、修改、编辑.后台管理系统实现了对信息的编辑.系统利用Access数据库技术动态存储信息内容,利用ASP技术动态显示信息内容.  相似文献   
36.
The development and use of indicators is common practice in efforts to promote urban sustainability. Indicators used to measure urban sustainability tend to focus narrowly on describing the current state of the urban system. Although a time series analysis using these indicators may lend insights into trends towards or away from certain ‘sustainability’ goals, existing indicators of urban sustainability do not provide information on the ability or the likelihood that the current system state can be maintained or improved over time. Indicators that incorporate a measure of system resilience would provide useful information on system sustainability. Through development of a new indicator, Water Provision Resilience (WPR), we provide an example of how measures of resilience could be incorporated into sustainability indicators. The new indicator adds six color codings to the existing indicator ‘percent of the population with access to safe water.’ Each color coding represents a measure of the ability of the water system to maintain or improve the current percent of the population with access to safe water in key areas of the water provision sector: supply, infrastructure, service provision, finances, water quality and governance. The metric is then applied to three cities. The goal in developing this metric is to provide a starting point for re-thinking the metrics used to measure progress and sustainability in order to incorporate the ability to absorb and adapt to stresses into sustainability analysis.  相似文献   
37.
利用Access开发岩土工程勘察管理数据库   总被引:2,自引:0,他引:2  
李洪 《化工矿产地质》2001,23(3):169-180
Access设计岩土工程勘察管理数据库 ,能对岩土工程勘察各个环节实行全面的、信息化的管理。对各环节的管理信息实现录入、查询、修改、打印数据和表格的功能 ;实现管理图件 (图片 )、声音、影像等多媒体功能 ;实现信息动态发布的网络化功能。岩土工程勘察管理数据库的开发利用简化了工作过程 ,规范了作业行为 ,提高了工作效率 ,推动了信息化、网络化建设 ,具有重要的实用价值  相似文献   
38.
如何实现图形数据与属性数据的一体化存储是目前的研究热点。本文以MS Access关系数据库为例,说明空间及多媒体数据实现全关系型存储的理论。从而能克服传统的混合结构模型中空间数据库和属性数据库的繁琐联结的弱点。  相似文献   
39.
本系统可以完成山西省各气象台站人工站及自动站多种类型的气象观测资料的接收,对接收后的资料进行解包,并将资料接收情况进行登记,系统把资料接收情况生成回执文件反馈回资料发送单位。业务管理部门可以通过系统制作的报表和Intranet查询登记库来了解资料到达情况。本系统还简化了各种资料的审核过程。  相似文献   
40.
Based on empirical evidence, the article looks at the implications of private sector participation (PSP) for the delivery of water supply and sanitation to the urban and peri-urban poor in developing countries, with particular reference to Africa and Latin America. More precisely, the article addresses the impact produced by multinational companies’ (MNCs) strategies, in light of the pursuit of profitability, on the extension of connections to the pipeline network. It does so by questioning the assumptions that greater private sector efficiency and innovation, together with contract design, will enable the sustainable extension of service coverage to low income dwellers. The strategies of the major water MNCs are considered both in relation to the global expansion of their operations and the adjustment of local strategies to commercial considerations. The latter might result in identifying profitable markets, modifying contractual provisions, attempting to reduce costs and increase income, reducing risks and exiting from non-performing contracts. The evidence reviewed allows for re-assessing the relative roles of the public and private sectors in extending and delivering water services to the poor. First, the most far reaching innovative approaches to extending connections are more likely to come from communities, public authorities and political activity than from MNCs. Secondly, whenever MNCs are liable to exit from non-profitable contracts, the public sector has no other option than to deal with external risks affecting continuity of provision. Finally, market limitations affecting MNCs’ ability to serve marginal populations and access cheap capital do not apply to well-organised, politically led public sector undertakings.  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