全文获取类型
收费全文 | 22550篇 |
免费 | 1843篇 |
国内免费 | 2885篇 |
专业分类
安全科学 | 3043篇 |
废物处理 | 369篇 |
环保管理 | 4029篇 |
综合类 | 12582篇 |
基础理论 | 2193篇 |
环境理论 | 19篇 |
污染及防治 | 1271篇 |
评价与监测 | 1185篇 |
社会与环境 | 1645篇 |
灾害及防治 | 942篇 |
出版年
2024年 | 44篇 |
2023年 | 327篇 |
2022年 | 534篇 |
2021年 | 740篇 |
2020年 | 801篇 |
2019年 | 601篇 |
2018年 | 487篇 |
2017年 | 740篇 |
2016年 | 836篇 |
2015年 | 881篇 |
2014年 | 1004篇 |
2013年 | 1324篇 |
2012年 | 1479篇 |
2011年 | 1663篇 |
2010年 | 1192篇 |
2009年 | 1272篇 |
2008年 | 979篇 |
2007年 | 1529篇 |
2006年 | 1552篇 |
2005年 | 1326篇 |
2004年 | 1170篇 |
2003年 | 1091篇 |
2002年 | 980篇 |
2001年 | 822篇 |
2000年 | 791篇 |
1999年 | 696篇 |
1998年 | 451篇 |
1997年 | 419篇 |
1996年 | 265篇 |
1995年 | 286篇 |
1994年 | 206篇 |
1993年 | 209篇 |
1992年 | 127篇 |
1991年 | 85篇 |
1990年 | 63篇 |
1989年 | 32篇 |
1988年 | 44篇 |
1987年 | 22篇 |
1986年 | 15篇 |
1985年 | 20篇 |
1984年 | 25篇 |
1983年 | 19篇 |
1982年 | 17篇 |
1981年 | 16篇 |
1980年 | 18篇 |
1979年 | 18篇 |
1978年 | 7篇 |
1973年 | 9篇 |
1972年 | 8篇 |
1971年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
1.
Hossein Karami Romina Sayahnia Hossein Mahmoudi Hossein Azadi Sadegh Salehi 《Natural resources forum》2023,47(1):60-86
Urbanization and mass movement of the population from rural areas and small cities to megacities have led to environmental, economic, and social problems in Iran. In dealing with these challenges, assessing resource and environmental carrying capacity (RECC) is considered an effective method to leverage space and capital to achieve sustainable development. This study aimed to rank the provincial RECC in Iran. Toward this purpose, environmental indices were generated from remotely sensed and statistical census data. Then, the provinces were scored in terms of environmental, economic, and infrastructural carrying capacities, and RECC using the mean variance analysis method. Results demonstrated that in most areas, there is no relationship between economic and infrastructural capacities and development. Statistically, a correlation coefficient of −0.53 between economic and environmental carrying capacities indicated excessive use of environmental capacities. Moreover, the spatial distribution pattern of environmental, economic, and infrastructural carrying capacity was entirely heterogeneous between the provinces; there was a northeast–southwest pattern in terms of infrastructural capacity and an economic pattern from north to south. The distribution pattern of RECC is most consistent with the environmental capacity, pointing at the high weight of the indicators of the RECC model. In conclusion, this research offers a new vision for policymakers and provides a theoretical and applicable framework for implementing sustainable strategies in land-use planning. It is recommended that the RECC concept and tools can be used not only for planning but also for measuring the efficiency of spatial development programs and establishing land balances in the region. 相似文献
2.
3.
Jennifer M. Sanders C. Rhett Jackson Meredith Welch-Devine 《Journal of the American Water Resources Association》2023,59(4):803-823
Despite long-standing knowledge of the benefits of riparian buffers for mitigating nonpoint source pollution, many streams are unprotected by buffers. Even landowners who understand ecological values of buffers mow riparian vegetation to the streambank. Do trends in rural riparian conditions reflect the development of riparian forest science? What motivates residential riparian management actions? Using high-resolution orthoimagery, we quantified riparian conditions and trends between 1998 and 2015 in the rural upper Little Tennessee River basin in Macon County, North Carolina and explored how landowners view riparian zone management and riparian restoration programs. Buffer composition in 2015 was as follows: no buffer (32.5%), narrow (19.3%), forested (26.7%), shrub (7.2%), and intermediate (7.0%). Relative to 1998, the greatest decrease occurred in the no buffer class (−17.7%, 46 km) and the largest increases occurred in the shrub (+72.5%, 20 km) and narrow (12.6%, 14 km) classes. Forested buffer marginally increased. Semi-structured interview data suggest that landowners prioritize recreational and scenic aspects of riparian buffers over ecological functions such as filtration and bank stabilization. Riparian restoration programs might be made more enticing to non-adopters if outreach language appealed to landowner priorities, design elements demonstrated intentional management, and program managers highlighted areas where ecological goals and landowner values align. 相似文献
4.
5.
为了完善现有煤与瓦斯共采技术,创新煤与瓦斯共采方法,对错层位巷道布置下的煤与瓦斯共采系统展开研究,利用相似模拟试验,分析错层位巷道布置覆岩运动情况,预测其开采围岩裂隙发育和瓦斯运移形式,提出了创新煤与瓦斯共采技术构想。研究结果表明:采空区覆岩三带高度随接续工作面的增加而增大,相邻采空区垮落矸石压实区呈现“O-L-O”形变化,多个相邻采空区覆岩出现大“O”形圈裂隙带;相邻采空区内瓦斯可实现相互运移,大“O”形圈裂隙带内赋存大量瓦斯气体;研究提出了地面钻井抽采瓦斯、走向高位瓦斯抽采巷和外错尾巷穿层钻孔3种煤与瓦斯共采技术,比传统巷道布置情况下的煤与瓦斯共采技术在安全、经济等方面更具优势。 相似文献
6.
Conservation conflicts are gaining importance in contemporary conservation scholarship such that conservation may have entered a conflict hype. We attempted to uncover and deconstruct the normative assumptions behind such studies by raising several questions: what are conservation conflicts, what justifies the attention they receive, do conservation-conflict studies limit wildlife conservation, is scientific knowledge stacked against wildlife in conservation conflicts, do conservation-conflict studies adopt a specific view of democracy, can laws be used to force conservation outcomes, why is flexibility needed in managing conservation conflicts, can conservation conflicts be managed by promoting tolerance, and who needs to compromise in conservation conflicts? We suggest that many of the intellectual premises in the field may defang conservation and prevent it from truly addressing the current conservation crisis as it accelerates. By framing conservation conflicts as conflicts between people about wildlife or nature, the field insidiously transfers guilt, whereby human activities are no longer blamed for causing species decline and extinctions but conservation is instead blamed for causing social conflicts. When the focus is on mitigating social conflicts without limiting in any powerful way human activities damaging to nature, conservation-conflict studies risk keeping conservation within the limits of human activities, instead of keeping human activities within the limits of nature. For conservation to successfully stop the biodiversity crisis, we suggest the alternative goal of recognizing nature's right to existence to maintenance of ecological functions and evolutionary processes. Nature being a rights bearer or legal person would imply its needs must be explicitly taken into account in conflict adjudication. If, even in conservation, nature's interests come second to human interests, it may be no surprise that conservation cannot succeed. 相似文献
7.
Xueqi Fan Jie Gao Wenchao Li Jun Huang Gang Yu 《Frontiers of Environmental Science & Engineering》2020,14(1):8
8.
9.
利用专业噪声测量设备及噪声频谱分析设备,对地铁站附属地下餐饮空间区域噪声进行监测,绘制噪声小时频谱。经分析发现地铁附属地下餐饮空间声环境会受到客流、空间位置及餐铺建筑结构影响,因此在该类空间进行降噪设计中应充分考虑这些因素的影响。 相似文献
10.