全文获取类型
收费全文 | 7914篇 |
免费 | 383篇 |
国内免费 | 1012篇 |
专业分类
安全科学 | 1183篇 |
废物处理 | 207篇 |
环保管理 | 724篇 |
综合类 | 3833篇 |
基础理论 | 602篇 |
污染及防治 | 1877篇 |
评价与监测 | 464篇 |
社会与环境 | 295篇 |
灾害及防治 | 124篇 |
出版年
2023年 | 23篇 |
2022年 | 106篇 |
2021年 | 102篇 |
2020年 | 113篇 |
2019年 | 110篇 |
2018年 | 67篇 |
2017年 | 286篇 |
2016年 | 307篇 |
2015年 | 222篇 |
2014年 | 79篇 |
2013年 | 87篇 |
2012年 | 429篇 |
2011年 | 566篇 |
2010年 | 206篇 |
2009年 | 246篇 |
2008年 | 574篇 |
2007年 | 613篇 |
2006年 | 434篇 |
2005年 | 421篇 |
2004年 | 345篇 |
2003年 | 336篇 |
2002年 | 315篇 |
2001年 | 261篇 |
2000年 | 172篇 |
1999年 | 123篇 |
1998年 | 36篇 |
1997年 | 29篇 |
1996年 | 31篇 |
1995年 | 65篇 |
1994年 | 41篇 |
1993年 | 86篇 |
1992年 | 79篇 |
1991年 | 109篇 |
1990年 | 123篇 |
1989年 | 94篇 |
1988年 | 194篇 |
1987年 | 245篇 |
1986年 | 128篇 |
1985年 | 238篇 |
1984年 | 223篇 |
1983年 | 197篇 |
1982年 | 161篇 |
1981年 | 144篇 |
1980年 | 129篇 |
1979年 | 78篇 |
1978年 | 82篇 |
1977年 | 37篇 |
1976年 | 63篇 |
1975年 | 48篇 |
1974年 | 69篇 |
排序方式: 共有9309条查询结果,搜索用时 78 毫秒
1.
微塑料是水环境中一种含量丰富的污染物。但关于其对幼鱼的影响情况知之甚少。我们考察了塑料微珠的密度增大对黑头软口鲦(Pimephales promelas)幼鱼觅食和生长的影响。我们发现微塑料对幼鱼摄食幼虫卤虫无节幼体(Artemia nauplii)的摄食量影响很小,对30天体长也基本无影响。
精选自Timothy David Malinich, Nathan Chou, Maria S. Sepúlveda, Tomas O. H??k. No evidence of microplastic impacts on consumption or growth of larval Pimephales promelas. Environmental Toxicology and Chemistry,2018,37:2912-2918.
详情请见 https://doi.org/10.1002/etc.4257 相似文献
2.
3.
Kennedy N. Igbokwe 《中国人口.资源与环境(英文版)》2005,(1)
1 INTRODUCTIONIn the past, natural resources management initiatives havefocused on large but specific sector projects such as dams,reservoirs for water supply schemes, irrigation systems,crop production, at forestation, etc. Often these projectswere treated as technical and administrative issues ratherthan as a socio-economic and political one. However, thehigh social and environmental cost of such schemes haveled to a change of paradigm since the 1980s towards small-scale community projec… 相似文献
4.
Removal of thiobencarb in aqueous solution by zero valent iron 总被引:2,自引:2,他引:0
A cost-effective method with zero valent iron (ZVI) powder was developed for the purification of thiobencarb (TB)-contaminated water. The removal treatment was performed in the batch system. A sample solution of 10 ml containing 10 microg ml(-1) of TB could be almost completely treated by 100mg of ZVI at 25 degrees C for 12h of treatment time. Since the formation of chloride ion in the aqueous solution during the treatment of TB was observed, the removal of TB with ZVI may contain two processes: reduction (degradation) and adsorption. Because the present treatment for TB is simple, easy handling and cheap, the developed technology with ZVI can contribute to the treatment of agricultural wastewaters. 相似文献
5.
This study combined laboratory based microcosm systems as well as field experiments to evaluate the mobility of atrazine on a Ultisol under humid tropical conditions in Brazil. Results from sorption experiments fit to the Freundlich isotherm model [K(f) 0.99 mg kg(-1)/(mg l(-1))(1/n)], and indicate a low sorption capacity for atrazine in this soil and consequently large potential for movement by leaching and runoff. Microcosm systems using (14)C-atrazine to trace the fate of the applied herbicide, showed that 0.33% of the atrazine was volatilized, 0.25% mineralized and 6.89% was recorded in the leachate. After 60 d in the microcosms, 75% of the (14)C remained in the upper 5 cm soil layer indicating atrazine or its metabolites remained close to the soil surface. In field experiments, after 60 d, only 5% of the atrazine applied was recovered in the upper soil layers. In the field experiments atrazine was detected at a depth of 50 cm indicating leaching. Simulating tropical rain in field experiments resulted in 2.1% loss of atrazine in runoff of which 0.5% was adsorbed onto transported soil particles and 1.6% was in solution. Atrazine runoff was greatest two days after herbicide application and decreased 10 fold after 15 d. The use of atrazine on Ultisols, in the humid tropics, constitutes a threat to water quality, causing surface water and ground water pollution. 相似文献
6.
Improvements on Flood Alleviation in Germany: Lessons Learned from the Elbe Flood in August 2002 总被引:1,自引:0,他引:1
The increase in damage due to natural disasters is directly related to the number of people who live and work in hazardous
areas and continuously accumulate assets. Therefore, land use planning authorities have to manage effectively the establishment
and development of settlements in flood-prone areas in order to avoid the further increase of vulnerable assets. Germany faced
major destruction during the flood in August 2002 in the Elbe and Danube catchments, and many changes have been suggested
in the existing German water and planning regulations. This article presents some findings of a “Lessons Learned” study that
was carried out in the aftermath of the flood and discusses the following topics: 1) the establishment of comprehensive hazard
maps and flood protection concepts, 2) the harmonization of regulations of flood protection at the federal level, 3) the communication
of the flood hazard and awareness strategies, and 4) how damage potential can be minimized through measures of area precaution
such as resettlement and risk-adapted land use. Although attempts towards a coordinated and harmonized creation of flood hazard
maps and concepts have been made, there is still no uniform strategy at all planning levels and for all states (Lae
nder) of the Federal Republic of Germany. The development and communication of possible mitigation strategies for “unthinkable
extreme events” beyond the common safety level of a 100-year flood are needed. In order to establish a sustainable and integrated
flood risk management, interdisciplinary and catchment-based approaches are needed. 相似文献
7.
<正> 关于金伯利岩中金刚石及超基性岩和榴辉岩捕虏体形成的地幔假说,近几年来几乎已成为定理。对此问题的一些不同的看法,或是因为不值得引起严重注意未被提及,或是因为缺乏足够的论据和实际分析资料而完全被忽视。 相似文献
8.
2008年1月12日的全国安全生产工作会议上,国家安全监管总局局长李毅中在安全生产工作报告中指出:“在党中央、国务院的正确领导和上下各方的共同努力下,2007年,在国民经济持续快速发展、能源原材料和交通运输市场需求旺盛、经济总量和投资等大幅度增长的情况下,全国安全生产状况总体上继续趋稳趋好,较好地完成了国务院安委会年初确定的各项指标任务。”2007年安全生产工作进展情况和取得的成绩突出表现在以下几个方面。 相似文献
9.
10.
Xiang Laisheng Guo Yajun Li Zhanfang . School of Management Northeastern University Shenyang Liaoning China . Development Research Center of Liaoning People’s Government Shenyang Liaoning China 《中国人口.资源与环境(英文版)》2007,5(2):49-52
In the high technology industry, small and medium sized technology enterprises (SMSTEs) play a pivotal role in advancing the whole industry. To achieve sustainable development, they need to extend their scope of business activities beyond a national view and exploit international market actively to meet international competitions that increase quickly in the form of allocating resources within the scope of the world. However, the SMSTEs are also facing risks associated with themselves during the process of exploiting international market owing to their own restrictions, so what they should do is to consider risk evaluations in exploiting the international market. 相似文献