全文获取类型
收费全文 | 239篇 |
免费 | 12篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 70篇 |
废物处理 | 1篇 |
环保管理 | 15篇 |
综合类 | 51篇 |
基础理论 | 17篇 |
污染及防治 | 17篇 |
评价与监测 | 24篇 |
社会与环境 | 5篇 |
灾害及防治 | 55篇 |
出版年
2023年 | 5篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 10篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 8篇 |
2012年 | 16篇 |
2011年 | 28篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 7篇 |
2007年 | 15篇 |
2006年 | 9篇 |
2005年 | 14篇 |
2004年 | 7篇 |
2003年 | 10篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 11篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1983年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有255条查询结果,搜索用时 0 毫秒
201.
土壤和地下水石油污染的生物治理 总被引:10,自引:1,他引:10
概述了石油生物降解速率的主要影响因素,烃类的组成与状态,烃类降解微生物,温度与pH值,O2和营养。介绍了土壤和地下水石油污染的两种生物治理方法;菌种法和营养物法,认为该法具有安全,经济,无二次污染,不需大型设备,操作简单等优点,但也具有一定的局限性。 相似文献
202.
Cross-borehole ground penetrating radar (XBGPR) is used in monitoring a long-term vadose zone infiltration experiment at a test site in Socorro, NM in order to examine contaminant transport in the vadose zone. XBGPR attenuation tomography is conducted in order to test the ability of using images of electromagnetic attenuation for hydrogeologic investigations. The results of four pre-infiltration attenuation inversions shows standard deviations below 0.1 Np/m, and demonstrate the consistency of the XBGPR tomography technique for making time-lapse observations. Correlation to the core records indicates that XBGPR attenuation tomograms provide high-resolution images of clay distribution in the vadose zone. Water infiltration at the ground surface was initiated in February 1999 at a constant rate of 2.7 cm/day, and continued at this rate throughout the data collection experiment. Time-lapse attenuation tomograms show that attenuation increases by approximately 0.3 Np/m during the water infiltration, and indicate a snowplow effect may be occurring where salts are dissolved by the water and concentrated at the front of the plume. Seasonal temperature changes may also cause changes in electromagnetic attenuation images, and masking the evidence of water infiltration. Thus caution must be taken when using time-lapse attenuation images to interpret the movement of a water plume during a long-term experiment as temperature changes. 相似文献
203.
Bekins BA Cozzarelli IM Godsy EM Warren E Essaid HI Tuccillo ME 《Journal of contaminant hydrology》2001,53(3-4):387-406
A multidisciplinary study of a crude-oil contaminated aquifer shows that the distribution of microbial physiologic types is strongly controlled by the aquifer properties and crude oil location. The microbial populations of four physiologic types were analyzed together with permeability, pore-water chemistry, nonaqueous oil content, and extractable sediment iron. Microbial data from three vertical profiles through the anaerobic portion of the contaminated aquifer clearly show areas that have progressed from iron-reduction to methanogenesis. These locations contain lower numbers of iron reducers, and increased numbers of fermenters with detectable methanogens. Methanogenic conditions exist both in the area contaminated by nonaqueous oil and also below the oil where high hydrocarbon concentrations correspond to local increases in aquifer permeability. The results indicate that high contaminant flux either from local dissolution or by advective transport plays a key role in determining which areas first become methanogenic. Other factors besides flux that are important include the sediment Fe(II) content and proximity to the water table. In locations near a seasonally oscillating water table, methanogenic conditions exist only below the lowest typical water table elevation. During 20 years since the oil spill occurred, a laterally continuous methanogenic zone has developed along a narrow horizon extending from the source area to 50-60 m downgradient. A companion paper [J. Contam. Hydrol. 53, 369-386] documents how the growth of the methanogenic zone results in expansion of the aquifer volume contaminated with the highest concentrations of benzene, toluene, ethylbenzene, and xylenes. 相似文献
204.
鱼外渔场海洋生物体内重金属和多环芳烃含量水平与食用风险评价 总被引:2,自引:0,他引:2
本文对2018年2月采自东海鱼外渔场的海洋生物(包括鱼类、头足类和甲壳类)体内的5种重金属(Cu、Pb、Cr、As、Cd)和16种多环芳烃(PAHs)的残留水平进行了测定,分析了污染物在生物体内的累积特性并计算了潜在的食用风险,并结合氮稳定同位素技术,初步探讨了生物体内重金属和PAHs的营养级传递特性。结果表明:5种重金属在生物中的平均浓度表现为CuPbCrAsCd;参照我国《食品中污染物限量》和《无公害食品水产品中有毒有害物质限量》,重金属Cu、Cd和Cr均未超过食用标准,但Pb和As的超标现象较为严重。与世界其他范围海域生物体内重金属浓度相比,该渔场生物体内Cu和Pb浓度较高。∑PAHs的平均浓度为283 ng·g~(-1)dw,以低环PAHs(2~3环)占比较大,且主要贡献单体为萘(NAP),总体处于较低污染水平。海洋生物对重金属的富集能力较PAHs高,尤其对Cu的富集最为明显。但风险计算结果表明,重金属和PAHs都不会对消费者的人体健康产生明显风险。重金属Cu和Cd浓度随营养级的升高出现了稀释现象,但重金属Pb、Cr、As和PAHs的营养传递特性不明显,覆盖完整食物链的污染物营养传递特性有待进一步深入研究。 相似文献
205.
坍塌事故已成为建筑施工中又一重大伤害事故 总被引:1,自引:0,他引:1
何建安 《中国安全科学学报》1995,5(5):3-5
近年来在工程施工中因坍塌事故而造成的重大伤亡事故屡有发生。文章根据工程事故实例,对坍塌事故进行了分类剖析,探讨导致各类坍塌伤亡事故发生的原因并提出相应的预防措施。 相似文献
206.
207.
William L. Magette Adel Shirmohammadi Billy V. Lessley Richard A. Weismiller 《Journal of the American Water Resources Association》1989,25(3):599-606
ABSTRACT: Ground water quality is an environmental issue of national concern. Agricultural activities, because they involve large land areas, often are cited as a major contributor of ground water contaminants. It appears that some degree of ground water contamination from agricultural land use is inevitable, especially where precipitation exceeds evapotranspiration. For this reason, and because agriculture differs significantly from point sources of pollution, farmers, policymakers, and scientists need alternative management strategies by which to protect ground water. Mathematical models coupled to geographic information systems to form expert systems can be important management tools for both policymakers and agricultural producers. An expert system can provide farmers, researchers, and environmental managers with information by which to better manage agricultural production systems to minimize ground water contamination. Significant research is necessary to perfect such a system, necessitating interim ground water management strategies that include not only a strong research program, but educational and public policy components as well. 相似文献
208.
ABSTRACT: An analytical framework is presented that identifies the tradeoffa that a regional authority desiring to enhance ground water quality is confronted with as it strives to balance the preferences of farmers and households while endeavoring to maximize net regional welfare. The basic rule developed indicates that the regional authority must choose a policy whereby any increase (decrease) in regional income is just equal to the decrease (increase) in net benefits to households. 相似文献
209.
210.