首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   246篇
  免费   3篇
安全科学   9篇
废物处理   2篇
环保管理   13篇
综合类   47篇
基础理论   58篇
污染及防治   111篇
评价与监测   3篇
社会与环境   5篇
灾害及防治   1篇
  2022年   3篇
  2021年   2篇
  2019年   2篇
  2018年   3篇
  2017年   5篇
  2015年   4篇
  2013年   6篇
  2012年   11篇
  2011年   6篇
  2010年   5篇
  2009年   7篇
  2008年   8篇
  2007年   6篇
  2006年   4篇
  2005年   4篇
  2004年   3篇
  2003年   8篇
  2002年   6篇
  1999年   8篇
  1998年   2篇
  1997年   2篇
  1996年   5篇
  1995年   5篇
  1994年   6篇
  1993年   9篇
  1992年   3篇
  1991年   5篇
  1989年   2篇
  1986年   4篇
  1984年   8篇
  1983年   4篇
  1982年   6篇
  1981年   10篇
  1979年   6篇
  1978年   7篇
  1977年   4篇
  1976年   10篇
  1975年   6篇
  1974年   12篇
  1973年   11篇
  1972年   2篇
  1963年   2篇
  1960年   1篇
  1959年   1篇
  1958年   1篇
  1954年   1篇
  1933年   1篇
  1927年   1篇
  1925年   1篇
  1914年   1篇
排序方式: 共有249条查询结果,搜索用时 15 毫秒
131.
In this study, we investigated the toxic effects of water-soluble elements from a contaminated soil via gavage in a single dose, simulating a geophagy event. The contaminated soil was collected in a field located in an industrial complex, and the control soil was collected in a reference area. Metabolic and behavioral parameters in Wistar male rats were measured after 24 and 96 h of gavage. After 96 h, the major organs were weighed, blood was collected to check hematological parameters, the bone marrow was taken for the micronucleus test, and the liver was used for evaluating the total antioxidant capacity, lipoperoxidation and protein carbonylation. Animals exposed to contaminated soil presented a few significant alterations by comparison with control animals: TBARS and protein carbonyl levels increased, the relative weight of the kidneys increased, metabolic parameters (body weight gain, food intake, water consumption, urine and feces production) depressed and there was behavioral alteration. These findings suggest that soils impacted by atmospheric contaminants can affect the organism physiological status jeopardizing the health of populations living in industrial areas. Finally, this study reassures that ingestion of potentially contaminated soils, even for short periods of time, can cause health risks.  相似文献   
132.
To contribute to the aspirations of recent international biodiversity conventions, protected areas (PAs) must be strategically located and not simply established on economically marginal lands as they have in the past. With refined international commitments under the Convention on Biological Diversity to target protected areas in places of “importance to biodiversity,” perhaps they may now be. We analyzed location biases in PAs globally over historic (pre‐2004) and recent periods. Specifically, we examined whether the location of protected areas are more closely associated with high concentrations of threatened vertebrate species or with areas of low agricultural opportunity costs. We found that both old and new protected areas did not target places with high concentrations of threatened vertebrate species. Instead, they appeared to be established in locations that minimize conflict with agriculturally suitable lands. This entrenchment of past trends has substantial implications for the contributions these protected areas are making to international commitments to conserve biodiversity. If protected‐area growth from 2004 to 2014 had strategically targeted unrepresented threatened vertebrates, >30 times more species (3086 or 2553 potential vs. 85 actual new species represented) would have been protected for the same area or the same cost as the actual expansion. With the land available for conservation declining, nations must urgently focus new protection on places that provide for the conservation outcomes outlined in international treaties.  相似文献   
133.
This paper expands on a simple concept shared with us over three decades ago by Trevor Kletz: what you don’t have can’t leak. Despite many efforts at eliminating hazards through inherently safer process methodologies, as encouraged by Kletz and others, the reality is that the use of hazardous materials and processes is still quite common. Therefore, we consider those processes that still handle hazardous materials – the cases where what you do not manage will leak and may cause a fire, explosion or toxic release. Our intended audience is quite broad. As Kletz has noted over the years, it is not just the people running a process who are responsible for its safety, but also those who make decisions on its design, operation, maintenance, staffing, etc. We hope that this paper contributes to an understanding of why we continue to have hazardous materials leak, potentially leading to accidents that cause fatalities, serious injuries, property damage, and environmental harm.We expand on the fundamental equation for risk, a function of both the frequency and the consequence of a possible event, by considering the effects of poor operational discipline on risk, and ultimately, on the possible leak or release of the hazardous material. Continued safe operation involving hazardous materials depends on and is sustained by the operational discipline of everyone involved in the design of processes and their continuing operation and maintenance. What we do not manage will leak and therein lays the fundamental challenge that Kletz continues to emphasize today.  相似文献   
134.
135.
136.
beta-Hexachlorocyclohexane-14C (1.5 ppm) was administered in the diet to rats for one week. During the elimination phase three therapeutic agents were fed to enhance the clearance. Renal and fecal excreted radioactive products were collected for 8 weeks and extracted. Although significant differences in the total excreted amount of radioactivity were registered between controls and treated rats, there were no quantitative differences in the extractability of the excreta and no differences in the chemical nature of metabolites found. Radioactivity in urine consisted to 100% of conversion products, about 30% of which were unextractable residues. In the organic soluble fraction the 2,4,6-trichlorophenol was the major metabolite in urine and the only metabolite detected in feces. Minor conversion products of beta-HCH in urine were a trichlorohydroxyme-thoxybenzene, a dichlorophenol and a trace of a tetrachlorocyclohexane-isomer.  相似文献   
137.
138.
139.
140.
Artisanal small-scale gold miners (ASM) occasionally employ whole ore amalgamation by adding mercury into ball mills to recover gold. In this process, 25–30% of the mercury added is lost to the environment. It is also inefficient less than 30% of gold is recovered. Amalgamation, followed by cyanidation, has been observed at many artisanal mining sites. This combination poses additional environmental and health consequences. Tests with ore samples from Talawaan, North Sulawesi, Indonesia indicate the possibility of replacing mercury by cyanidation in the ball mill, reaching gold extraction of 93% in 6 h of leaching. The gold in the Indonesian ore sample is fine and less than 8% of gold recovery was obtained with gravity concentration of the ore ground 80% below 0.25 mm, which is a reasonably fine grain size for artisanal gold operations. Replacing mercury addition with cyanidation in ball mills was implemented in one artisanal gold mining operation in Portovelo, Ecuador, achieving 95% of gold extraction in 8 h of mill leaching. This technique demonstrated a drastic improvement in gold recovery. It was found to be a simple, inexpensive technique well accepted by local miners. The results from laboratory and field tests are promising; however a thorough investigation into the socio-economic and environmental aspects of this presented alternative must be conducted prior to introduction.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号