全文获取类型
收费全文 | 4449篇 |
免费 | 290篇 |
国内免费 | 332篇 |
专业分类
安全科学 | 396篇 |
废物处理 | 152篇 |
环保管理 | 1286篇 |
综合类 | 1834篇 |
基础理论 | 426篇 |
环境理论 | 20篇 |
污染及防治 | 141篇 |
评价与监测 | 66篇 |
社会与环境 | 676篇 |
灾害及防治 | 74篇 |
出版年
2024年 | 7篇 |
2023年 | 46篇 |
2022年 | 82篇 |
2021年 | 98篇 |
2020年 | 136篇 |
2019年 | 123篇 |
2018年 | 122篇 |
2017年 | 206篇 |
2016年 | 231篇 |
2015年 | 184篇 |
2014年 | 163篇 |
2013年 | 346篇 |
2012年 | 304篇 |
2011年 | 383篇 |
2010年 | 273篇 |
2009年 | 239篇 |
2008年 | 170篇 |
2007年 | 281篇 |
2006年 | 208篇 |
2005年 | 179篇 |
2004年 | 157篇 |
2003年 | 151篇 |
2002年 | 121篇 |
2001年 | 106篇 |
2000年 | 120篇 |
1999年 | 107篇 |
1998年 | 57篇 |
1997年 | 66篇 |
1996年 | 63篇 |
1995年 | 49篇 |
1994年 | 57篇 |
1993年 | 50篇 |
1992年 | 29篇 |
1991年 | 29篇 |
1990年 | 20篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 10篇 |
1979年 | 17篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1975年 | 3篇 |
1973年 | 8篇 |
1972年 | 3篇 |
1971年 | 8篇 |
排序方式: 共有5071条查询结果,搜索用时 468 毫秒
91.
Traditional knowledge and practices are important in prudent resource use and biodiversity conservation. The implications of modernization and changing lifestyle are discussed in the context of agriculture and resource use, the two sectors in which maximum modernization has occurred. The information was gathered through observations and structured interviews over three years (July 1996 to July 1999) of field work in the western Himalaya. It was observed that forest based subsistence agriculture has given way to the market dependant cash crop cultivation. That apart from loss of genetic diversity, has also resulted in the degradation of forests. The use of wild plants in the day-to-day activities has also declined and dependence on high value market products has increased. Currently, wild plants are used only if no other cheap substitute is available in the market or if the use is economically beneficial to the people. Thus, the knowledge gathered through ages of experience is eroding because of the activities geared for short-term economic benefits which, in long run, may not be sustainable. 相似文献
92.
93.
94.
广州茶文化旅游资源的开发利用 总被引:7,自引:1,他引:7
作者立足于广州的茶文化,首先从社会普同性、文化信息共有性、文化模式的整合性等三个方面分析得出茶文化是广州民俗旅游资源的重要组成部分,并在此基础上对广州茶文化进行了分类,论述了其民俗旅游资源价值。最后,作者对开发广州茶文化旅游资源提出了一些建议。 相似文献
95.
西昌地区野生藜蒿资源的开发利用 总被引:5,自引:1,他引:5
作者根据对四川省西昌地区野生藜蒿资源的调查研究。论述了野生藜蒿的生物学特征,分布、开发利用价值,繁殖特性和经济效益,并提出了开发利用野生藜蒿资源的建议。 相似文献
96.
榆林地区甘草资源的开发与利用 总被引:1,自引:1,他引:1
根据对陕西省榆林地区甘草资源的调查研究,论述了甘草的生物学特征、分布、开发利用价值、栽培技术和经济效益,并提出了开发利用甘草资源的建议。 相似文献
97.
MICHAEL A. SCHUETT 《Environmental management》1997,21(2):239-246
/ This study intended to explore the perceptions of mountain bikingmanagement through a mail survey of state park directors in all 50 states.With a 100% response rate, it was found that 47 states permit mountainbiking in their state parks, however, few state parks have formalized plansto manage this outdoor activity. The management policies that do exist arenot followed on a statewide basis but vary within each state and at eachstate park. Many states have worked cooperatively with local mountain bikingclubs to develop and maintain mountain bike trails, promote rider education,and provide volunteer patrols on trails. The issue of user conflict surfacedwith almost three-fourths of the managers responding that conflict existedbetween mountain bikers and other trail users. This preliminary study shouldprompt further research with on-site managers focusing on the use ofmanagement plans for mountain biking, cooperation between managers and usergroups, and user conflict. It is recommended that an Internet-basedinformation clearinghouse or discussion group be made available to landmanagers by a national bicycling organization.KEY WORDS: Mountain biking; State parks; State park directors;Recreation resource management 相似文献
98.
This article does not focus on adaptation or mitigation policy directly but on an allied opportunity that exists for the Pacific
Islands via the auspices of the Climate Convention, because the existing very costly energy systems used in the Pacific Island
region are fossil-fuel dependent. It is argued here that efforts can be made towards the development of energy systems that
are ecologically sustainable because Pacific Island nations are eligible to receive assistance to introduce renewable energy
technology and pursue energy conservation via implementation mechanisms of the Climate Convention and, in particular, through
transfer of technology and via joint implementation.
It is contended that assistance in the form of finance, technology, and human resource development from developed countries
and international organizations would provide sustainable benefits in improving the local Pacific Island environments. It
is also emphasized that mitigation of greenhouse gas emissions is not the responsibility of the Pacific Islands as they contribute
very little on a per capita global scale and a tiny proportion of total global greenhouse gas emissions. 相似文献
99.
海南特区农村剩余劳动力资源的开发与利用 总被引:1,自引:0,他引:1
本文论述了海南特区农村剩余劳动力资源的现状及其影响劳动力资源开发利用的主要因素,提出了海南特区农村剩余劳动力资源开发与利用的途径。 相似文献
100.
湖北旅游资源特征与分区 总被引:1,自引:0,他引:1
本文在分析湖北省旅游资源的赋存状况和特征基础上,提出了湖北旅游的分区方案,包括鄂东综合旅游,鄂中名胜古迹,鄂西北山岳风光和鄂西南峡谷溶洞与民俗风情4大旅游区,旨在为湖北区域旅游开发与产业布局提供理论依据。 相似文献