全文获取类型
收费全文 | 12477篇 |
免费 | 183篇 |
国内免费 | 118篇 |
专业分类
安全科学 | 406篇 |
废物处理 | 557篇 |
环保管理 | 2024篇 |
综合类 | 1450篇 |
基础理论 | 3328篇 |
环境理论 | 3篇 |
污染及防治 | 3322篇 |
评价与监测 | 861篇 |
社会与环境 | 745篇 |
灾害及防治 | 82篇 |
出版年
2022年 | 118篇 |
2021年 | 103篇 |
2020年 | 80篇 |
2019年 | 106篇 |
2018年 | 193篇 |
2017年 | 184篇 |
2016年 | 291篇 |
2015年 | 210篇 |
2014年 | 285篇 |
2013年 | 1022篇 |
2012年 | 395篇 |
2011年 | 570篇 |
2010年 | 474篇 |
2009年 | 511篇 |
2008年 | 611篇 |
2007年 | 608篇 |
2006年 | 541篇 |
2005年 | 456篇 |
2004年 | 399篇 |
2003年 | 472篇 |
2002年 | 405篇 |
2001年 | 564篇 |
2000年 | 377篇 |
1999年 | 215篇 |
1998年 | 183篇 |
1997年 | 164篇 |
1996年 | 177篇 |
1995年 | 210篇 |
1994年 | 161篇 |
1993年 | 147篇 |
1992年 | 163篇 |
1991年 | 134篇 |
1990年 | 155篇 |
1989年 | 146篇 |
1988年 | 120篇 |
1987年 | 106篇 |
1986年 | 87篇 |
1985年 | 123篇 |
1984年 | 115篇 |
1983年 | 112篇 |
1982年 | 118篇 |
1981年 | 107篇 |
1980年 | 92篇 |
1979年 | 89篇 |
1978年 | 69篇 |
1977年 | 69篇 |
1976年 | 58篇 |
1975年 | 58篇 |
1974年 | 60篇 |
1973年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 468 毫秒
141.
Claus Beier Filip Moldan Richard F.Wright 《Ambio-人类环境杂志》2003,32(4):275-282
到2010年<哥德堡议定书>正式实施时,欧洲自20世纪70年代末以来已减少的酸化硫和氮释放量将进一步减少.这里我们论述了通过使用应用于3个大型"清洁雨"实验(即分别在挪威里斯达尔谢伊阿[Risdalsheia],瑞典耶德松[Gardsjon]以及丹麦克洛斯特海泽[Klosterhede]的所谓"屋顶实验")的酸化模型MAGIC讨论恢复酸化陆地生态系统的结果.<哥德堡议定书>的实施将启动通过重建盐基饱和恢复上述3处土壤的进程.恢复率较低,在今后30年中,盐基饱和增加不足5%.气候引发的风暴严重性的加剧将增加海盐输入生态系统的量.这将为土壤提供额外的碱阳离子,并使恢复速度翻一番,同时还将随着沉积的碱阳离子与存储在土壤中的酸性交换导致高海盐输入之后的强酸性脉动.因此,酸化集水区土壤和径流的进一步恢复将取决于酸沉积下降的数量和速率,在近岸系统的情况下,还取决于海盐输入事件的频率和强度. 相似文献
142.
Edmonds Jae Wise Marshall Pitcher Hugh Richels Richard Wigley Tom MacCracken Chris 《Mitigation and Adaptation Strategies for Global Change》1997,1(4):311-339
We report results from the application of an integrated assessment model, MiniCAM 1.0. The model is employed to explore the full range of climate change implications of the successful development of cost effective, advanced, energy technologies. These technologies are shown to have a profound effect on the future magnitude and rate of anthropogenic climate change. We find that the introduction of assumptions developed by a group of ‘bottom-up’ modelers for the LEESS scenarios into a ‘top-down’ model, the Edmonds-Reilly-Barns Model, leads to ‘top down’ emissions trajectories similar to those of the LEESS. The cumulative effect of advanced energy technologies is to reduce annual emissions from fossil fuel use to levels which stabilize atmospheric concentrations below 550 ppmv. While all energy technologies play roles, the introduction of advanced biomass energy production technology is particularly important. The consideration of all greenhouse related anthropogenic emissions, and in particular sulfur dioxide, is found to be important. We find that the consideration of sulfur dioxide emissions coupled to rapid reductions in carbon dioxide emissions leads to higher global mean temperatures prior to 2050 than in the reference case. This result is due to the short-term cooling impact of sulfate aerosols, which dominates the long-term warming impact of CO2 and CH4 in the years prior to 2050. We also show that damage calculations which use only mean global temperature and income may be underestimating damages by up to a factor of five. Disaggregating income reduces this to a factor of two, still a major error. Finally, the role of the discount rate is shown to be extraordinarily important to technology preference. 相似文献
143.
144.
In this paper we deal with the problem of identifying environmental principles for the design and operation of supply chains. The operations that are included in supply chains are briefly described along with the approaches that are applied in order to improve their environmental performance. A background of environmental principles for achieving eco-efficiency and building of environmentally friendly organizational systems is presented and emphasis is put on the application of such principles “from cradle to grave”. Then, environmental principles applicable to particular objects of logistics networks planning are identified and commented upon. In addition, selective case studies from the literature, which show the applicability of the formulated principles and their relevance to practice, are discussed. The paper concludes with some remarks regarding the benefits for companies and societies, in general, that occur as a result of the application of the formulated principles. 相似文献
145.
In Hydra vulgaris at the level of dissociated single cells endodermal cells adhere to each other more readily than to ectodermal cells at the
initial adhesion. The time required for adhesion to occur between two adjacent cells is shorter for both endodermal and ectodermal
homotypic cell adhesions once the initial adhesion of the first pair of cells has been established. It is confirmed that contact
of an aggregated pair with additional homotypic cells facilitates the occurrence of homotypic adhesions; heterotypic adhesions
are discouraged. This suggests that adhesion of homotypic cells contributes to an increased readiness for subsequent homotypic
cells to adhere.
Received: 25 August 1999 / Accepted in revised form: 11 January 2000 相似文献
146.
147.
148.
149.
150.