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   726篇
  免费   5篇
  国内免费   20篇
安全科学   18篇
废物处理   48篇
环保管理   73篇
综合类   41篇
基础理论   104篇
污染及防治   283篇
评价与监测   130篇
社会与环境   48篇
灾害及防治   6篇
  2023年   17篇
  2022年   77篇
  2021年   75篇
  2020年   19篇
  2019年   28篇
  2018年   32篇
  2017年   36篇
  2016年   39篇
  2015年   32篇
  2014年   35篇
  2013年   83篇
  2012年   25篇
  2011年   47篇
  2010年   36篇
  2009年   26篇
  2008年   22篇
  2007年   18篇
  2006年   14篇
  2005年   13篇
  2004年   11篇
  2003年   7篇
  2002年   5篇
  2001年   10篇
  2000年   1篇
  1999年   5篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1991年   1篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1985年   3篇
  1984年   1篇
  1983年   1篇
  1982年   5篇
  1981年   2篇
  1980年   4篇
  1979年   4篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1972年   1篇
  1964年   1篇
  1963年   1篇
排序方式: 共有751条查询结果,搜索用时 15 毫秒
671.
Environment, Development and Sustainability - Conservation of greenbelts is the most enduringly successful and popular basic need for today to protect green land, preserve ecological landscape and...  相似文献   
672.
The global agenda of sustainable development (SD) will get a major boost from the successful implementation of the Sustainable Development Goals (SDGs) in developing countries. This requires effective planning and understanding of the SDGs at the national level and developing sound SDG indicators that account for country priorities. Currently, there is no formal SDG indicator set in India, but the process for it is underway. This paper has attempted to propose a unique technique for identifying the most representative indicator set for SD measurement in India based on the SDGs. Considering the needs and preferences of the country, a three‐stage process is proposed to develop the priority indicator set. The application of the approach has been presented for SDG 7, which relates to energy. This is supported with a background on India's SD progress. The proposed technique is simple yet effective, and can be easily replicated by other developing countries.  相似文献   
673.
Juvenile Dicentrarchus labrax L. (sea bass) were exposed to water diluted 17beta-estradiol (E2) (200 ng/L and 2000 ng/L) and treated with intraperitoneal (i.p) injection E2 (0.5 mg/kg and 5 mg/kg) during 10 days in order to study its genotoxicity and peroxidative damage, measured as gill, blood, liver and kidney DNA integrity decrease using DNA strand breaks assay as well as liver, gill and kidney lipid peroxidation (LPO) respectively. Juvenile sea bass gill DNA integrity was significantly decreased for all E2 exposure conditions. However, no differences were detected either between different exposure routes or tested concentrations. Blood DNA integrity was significantly decreased by E2 5 mg/kg as well as by both water diluted E2 exposure conditions. The highest E2 dose (5 mg/kg) also promoted liver DNA integrity decrease. Liver and gill LPO significantly increased at the highest E2 i.p treatment. An increasing trend of gill and liver LPO, though statistically insignificant, was observed in D. labrax exposed to water diluted E2 in both tested concentrations. The current results demonstrated that DNA damage in juvenile sea bass is affected by the E2 exposure conditions, such as water diluted E2 versus i.p E2 injection since i.p E2 injection promoted higher genotoxicity effect, in terms of affected organs than water diluted E2. Moreover, the organ sensitivity to E2 was different, since gill showed more susceptibility than blood, liver and kidney. Concerning kidney LPO and DNA integrity no differences were found between treated and controls juvenile sea bass groups.  相似文献   
674.
Corrosion, which tends to increase the concentrations of certain metals in tap water, is one of the most important water quality problems as it can affect public health and public acceptance of water supply and the cost of providing safe water. In this context, this study aimed at investigating the scale formation tendency or corrosivity of groundwater in the semi-arid Harran Plain. The degree of scale formation tendency/corrosivity of water was determined considering pHs, Langelier Index, and Ryznar Index of groundwater samples. Except for well no.4, which is close to a local hot spring, all the wells had corrosive characteristics. The amount of CO2 from the soil zone respiration and high sulfate concentration in the wells are important factors affecting corrosiveness. Results showed that precipitation, excessive irrigation, and change in groundwater level caused seasonal variation in corrosive characteristics.  相似文献   
675.

Introduction  

This study was hypothesized that salicylic acid elevates the level of antioxidant system that will protect plants from the stress generated by nickel and/or salinity.  相似文献   
676.

Background, aim, and scope  

Lead, a major contaminant, is highly used in paint manufacturing due to its anticorrosive properties. Recent reports indicated high lead content among Indian paints used for commercial purposes. Painters are continuously exposed to these lead containing paints during painting of both commercial as well as residential buildings. Lead is well-known for its genotoxicty in occupational workers; however, in Indian painters the genotoxic effects of lead have not been reported to date. Therefore we aimed to study the genotoxic end points in painters due to their long-term exposure to these high lead-containing Indian paints.  相似文献   
677.
Several sex steroids and estrogenic drugs are genotoxic in varying conditions and cause oxidative stress, which has been a field of interest to study the molecular mechanism of the genetic damage. Among the estrogenic drugs, a strong toxic effect is exerted by diethylstilbestrol (DES). In the present study it has been attempted to study its genotoxic effects in human lymphocyte assay system along with ameliorative or anticlastogenic effects of vitamin C. The drug was used with different dosage of concentrations on human lymphocytes administered in vitro. The parameters used were Sister Chromatid Exchanges (SCEs) and Chromosomal Aberrations (CAs). Higher levels of clastogeny and SCEs have been observed indicating significant damaging effect by the drug. Interesting ameliorating effects were observed in the presence of vitamin C which is a well-known antioxidant. The results support the possibility of practical application of natural protectors against the mutagenic/oenotoxic action of chemical mutagens.  相似文献   
678.
679.
Two approaches were used to investigate the influence of dissolved oxygen (DO) and substrate availability on the formation and dynamics of "bioactive zones" in a water-saturated porous medium. A bioactive zone is defined as a region where a microbial community is sufficiently active to metabolize bioavailable substrates. In the first approach, microbial activity was characterized by monitoring the spatial and temporal variability of DO and aqueous substrate (salicylate and naphthalene) concentrations during miscible-displacement experiments. In the second approach, microbial activity was monitored using multiple fiber optics emplaced in the porous medium to detect luminescence produced by Pseudomonas putida RB1353, a bioluminescent reporter organism that produces light when salicylate (an intermediate of naphthalene degradation) is present. The results of both approaches show that the location and size of the bioactive zones were influenced by in situ DO and substrate availability. When DO was not a limiting factor (i.e., lower substrate input concentrations), the bioactive zone encompassed the entire column, with the majority of the microbial activity occurring between the inlet and midpoint. However, as the availability of DO became limiting for the higher substrate input experiments, the size of the bioactive zone shrank and was ultimately limited to the proximity of the column inlet.  相似文献   
680.
Farah MA  Ateeq B  Ali MN  Sabir R  Ahmad W 《Chemosphere》2004,55(2):257-265
Three widely used xenobiotics pentachlorophenol (PCP), 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-chloro-2,6-diethyl-N-(butoxymethyl) acetanilide (Butachlor) are evaluated for acute toxicity and stress behavior on freshwater fish (Heteropneustes fossilis, Clarias batrachus, Channa punctatus) and mosquito larvae (Culex pipiens fatigans). The experiment was carried out by medium treatment using intermittent flow-through system. Median lethal concentrations (LC50) were calculated by probit analysis. The LC50 values and 95% confidence intervals showed variable range for tested chemicals. Mosquito larvae generally appeared resistant than fish, while H. fossilis was found to be most sensitive. Stress signs in the form of behavioral changes are also observed. Both types of organisms are recommended as good bioindicator for the risk assessment of aquatic environment due to chemicals tested.  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