全文获取类型
收费全文 | 2205篇 |
免费 | 98篇 |
国内免费 | 740篇 |
专业分类
安全科学 | 167篇 |
废物处理 | 134篇 |
环保管理 | 160篇 |
综合类 | 1214篇 |
基础理论 | 388篇 |
污染及防治 | 685篇 |
评价与监测 | 78篇 |
社会与环境 | 59篇 |
灾害及防治 | 158篇 |
出版年
2024年 | 1篇 |
2023年 | 42篇 |
2022年 | 117篇 |
2021年 | 102篇 |
2020年 | 59篇 |
2019年 | 69篇 |
2018年 | 78篇 |
2017年 | 103篇 |
2016年 | 112篇 |
2015年 | 140篇 |
2014年 | 156篇 |
2013年 | 225篇 |
2012年 | 177篇 |
2011年 | 189篇 |
2010年 | 149篇 |
2009年 | 121篇 |
2008年 | 145篇 |
2007年 | 120篇 |
2006年 | 104篇 |
2005年 | 76篇 |
2004年 | 63篇 |
2003年 | 74篇 |
2002年 | 61篇 |
2001年 | 58篇 |
2000年 | 59篇 |
1999年 | 79篇 |
1998年 | 61篇 |
1997年 | 56篇 |
1996年 | 49篇 |
1995年 | 49篇 |
1994年 | 27篇 |
1993年 | 38篇 |
1992年 | 31篇 |
1991年 | 24篇 |
1990年 | 14篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1984年 | 3篇 |
1981年 | 2篇 |
1958年 | 1篇 |
排序方式: 共有3043条查询结果,搜索用时 960 毫秒
711.
本文主要对近30年来营口地震台记录的海城7.3级地震的余震观测资料进行分析,按不同的震级进行统计,分别作出M-T图和N-T图,可供今后监测工作参考。 相似文献
712.
Yanjun Meng Dazhen Tang Hao Xu Yong Li Lijun Gao 《Environmental science and pollution research international》2014,21(11):6964-6974
As one of the unconventional natural gas family members, coalbed methane (CBM) receives great attention throughout the world. The major associated problem of CBM production is the management of produced water. In the USA, Canada, and Australia, much research has been done on the effects and management of coalbed methane produced water (CMPW). However, in China, the environmental effects of CMPW were overlooked. The quantity and the quality of CMPW both vary enormously between coal basins or stratigraphic units in China. The unit produced water volume of CBM wells in China ranges from 10 to 271,280 L/well/day, and the concentration of total dissolved solids (TDS) ranges from 691 to 93,898 mg/L. Most pH values of CMPW are more than 7.0, showing the alkaline feature, and the Na-HCO3 and Na-HCO3-Cl are typical types of CMPW in China. Treatment and utilization of CMPW in China lag far behind the USA and Australia, and CMPW is mainly managed by surface impoundments and evaporation. Currently, the core environmental issues associated with CMPW in China are that the potential environmental problems of CMPW have not been given enough attention, and relevant regulations as well as environmental impact assessment (EIA) guidelines for CMPW are still lacking. Other potential issues in China includes (1) water quality monitoring issues for CMPW with special components in special areas, (2) groundwater level decline issues associated with the dewatering process, and (3) potential environmental issues of groundwater pollution associated with hydraulic fracturing. 相似文献
713.
Yuanfang Wang Baoyu Gao Qinyan Yue Xiao Zhan Xiaohui Si Chunxiao Li 《Journal of environmental management》2009,90(2):423-431
Epichlorohydrin-dimethylamine polymers with different intrinsic viscosity (η) and cationicity (τ) were synthesized. The flocculation performance and mechanism of these polymers in the removal of the reactive and disperse dyes from synthetic wastewater was investigated in terms of flocculation dynamics and color removal efficiency. The polymer flocculation efficiency was compared with that of polyaluminum chloride (PAC) and a composite flocculant based on polyaluminum chloride-epichlorohydrin-dimethylamine polyamine. The results showed that epichlorohydrin-dimethylamine polymer was effective over a pH range of 2–10 for the reactive and disperse dye removal (Reactive Brilliant Red and Disperse Yellow dyes). Epichlorohydrin-dimethylamine polymer with the highest η and τ gave the best reactive dye removal efficiency, and its adsorption-bridging and electric neutralization ability played important roles in the flocculation process. The higher the η viscosity of the epichlorohydrin-dimethylamine polymer, the better the flocculation performance of epichlorohydrin-dimethylamine polyamine, and stronger adsorption-bridging ability was obtained for removing the disperse dye from dyeing wastewaters. Epichlorohydrin-dimethylamine polymer achieved better decolorization performance when used together with PAC. 相似文献
714.
Health institutions in the People's Republic of China are under considerable challenge. Innovations in management systems may support the challenge to increase both efficiency and effectiveness. The balanced scorecard (BSC) is one such innovation. We have used a model to explore the factors that may impact the diffusion of the BSC in Chinese government hospitals. In particular, we concentrate on three factors - the outer context, the nature of the innovation and the communication and influence. The outer context and the nature of the innovation do provide an inducement to implement a BSC. The strength of the communication and influence may affect the level of take-up. However, we recognise that they may choose "the BSC not for any apparent technical excellence but for the legitimation that Western management practices may bring to local managers. 相似文献
715.
716.
通过资料调研、现场调查与检测,将获取的资料与法律、法规和标准要求相比较,对某炼化企业催化汽油吸附脱硫装置进行了职业病危害控制效果评价。 相似文献
717.
719.
Guangshui Na Wei Wei Shiyao Zhou Hui Gao Xindong Ma Lina Qiu Linke Ge Chenguang Bao Ziwei Yao 《环境科学学报(英文版)》2015,(2):8-13
In recent years, Dechloranes have been widely detected in the environment around the world.However, understanding and knowledge of Dechloranes in remote regions, such as the Arctic,remain lacking. Therefore, the concentrations of 5 Dechloranes in surface seawater, sediment,soil, moss, and dung collected from Ny-lesund in the Arctic were measured with the concentrations 93 pg/L, 342, 325, 1.4, and 258 pg/g, respectively, which were much lower than those in Asian and European regions. The mean ratios of anti-Dechlorane Plus(DP) to total DP(fanti) in seawater, sediment, soil, moss, dung, and atmospheric samples were 0.36, 0.21, 0.18,0.27, 0.66, and 0.43, respectively. Results suggested that the main source of DP in seawater,sediment, soil, and moss was long-range atmospheric transport. However, the ratio identified in dung was different, for which the migration behavior of the organism is probably the main source of DP. 相似文献
720.