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   42399篇
  免费   356篇
  国内免费   241篇
安全科学   899篇
废物处理   2039篇
环保管理   5483篇
综合类   5879篇
基础理论   12171篇
环境理论   28篇
污染及防治   10479篇
评价与监测   2999篇
社会与环境   2814篇
灾害及防治   205篇
  2022年   292篇
  2021年   316篇
  2020年   209篇
  2019年   295篇
  2018年   1925篇
  2017年   1839篇
  2016年   1841篇
  2015年   708篇
  2014年   881篇
  2013年   2463篇
  2012年   1535篇
  2011年   2752篇
  2010年   1952篇
  2009年   1787篇
  2008年   2323篇
  2007年   2742篇
  2006年   1328篇
  2005年   1210篇
  2004年   1138篇
  2003年   1123篇
  2002年   1142篇
  2001年   1285篇
  2000年   900篇
  1999年   573篇
  1998年   459篇
  1997年   440篇
  1996年   449篇
  1995年   498篇
  1994年   446篇
  1993年   398篇
  1992年   418篇
  1991年   376篇
  1990年   378篇
  1989年   411篇
  1988年   350篇
  1987年   301篇
  1986年   278篇
  1985年   308篇
  1984年   300篇
  1983年   328篇
  1982年   324篇
  1981年   272篇
  1980年   246篇
  1979年   270篇
  1978年   230篇
  1977年   195篇
  1976年   200篇
  1975年   192篇
  1974年   172篇
  1972年   198篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Environmental Science and Pollution Research - It is well known that road transport emits various trace elements into the environment, which are deposited in soils in the vicinity of roads,...  相似文献   
992.
Environmental Science and Pollution Research - Glyphosate is the most used herbicide worldwide. Many studies have reported glyphosate risks to aquatic organisms of different trophic levels....  相似文献   
993.

The presence of potentially hazardous elements (PHEs) in playground soils is generally associated with anthropogenic sources such as vehicle traffic, industries, construction sites, and biomass burning. Studies indicate that PHEs are harmful to human health and may even be carcinogenic. Therefore, the aim of this study was to evaluate the physicochemical, morphological, and mineralogical properties of soil samples from three public playgrounds located in the cities of Bogota, Medellin, and Barranquilla. Besides, the possible impacts caused by the aerodynamics of particles in Colombian cities were verified. The morphology, composition, and structure of the nanoparticles (NPs) (< 100 nm) present in these soils were evaluated by field emission scanning electron microscopy (FE-SEM) equipped with high-precision field emission (FE) and high-resolution transmission electron microscopy (HR-TEM). Soil samples were predominantly feldspar, quartz, and, to a lesser extent, clay minerals, carbonates, and hematites. The average content of PHEs was anthropogenically enriched in relation to the upper continental crust. As and Sn showed a large spatial variation, indicating the influence of local sources, such as vehicle traffic and industries. There is an inverse relationship between the total concentrations of some elements and their leachable fractions. The accumulation of traffic-derived PHEs has a negative impact on human health and the environment, which is alarming, especially for elements such as Pb, Sb, or As. Therefore, the presence of PHEs should receive greater attention from public health professionals, and limits should be set and exposures controlled. This study includes the construction of a baseline that provides basic information on pollution, its sources, and exposure routes for humans in the vicinity of Colombia’s major cities, characterized by their increasing urbanization and industrialization.

  相似文献   
994.

Natural products may be applied in a wide range of domains, from agriculture to food and pharmaceutical industries. In this study, the antioxidant properties and the capacity to inhibit some enzymatic activities of Euphorbia resinifera and Euphorbia officinarum aqueous extracts and honeys were assessed. The physicochemical characteristics were also evaluated. Higher amounts of iron, copper and aluminium were detected in E. officinarum honey, which may indicate environmental pollution around the beehives or inadequate storage of honey samples. This honey sample showed higher amounts of total phenols and better capacity for scavenging superoxide anion free radicals and DPPH free radicals as compared with E. resinifera honey, but poorer capacity for inhibiting lipoxygenase, acetylcholinesterase, tyrosinase and xanthine oxidase. The ratio plant mass:solvent volume (1:100) and extraction time (1 - 2 h) were associated with higher total phenols and better antioxidant activities and lipoxygenase, acetylcholinesterase and tyrosinase inhibitory activities, regardless of the plant species. The aqueous extracts had systematically higher in vitro activities than the respective honey samples.

  相似文献   
995.
Environmental Science and Pollution Research - A theoretical physicochemical and thermodynamic investigation of the adsorption of heavy metals Zn2+, Cd2+, Ni2+, and Cu2+on carbon-based adsorbents...  相似文献   
996.
Environmental Science and Pollution Research - A complete survey is presented on the inorganic composition of the euhalophyte annual succulent species Salicornia patula (Chenopodiaceae), including...  相似文献   
997.
Environmental Science and Pollution Research - Phytoremediation techniques have been proposed as ecological methods to clean up contaminated sites. This study is aimed to evaluate the effect of the...  相似文献   
998.
Environmental Science and Pollution Research - This work studies the effects of different bromide-based ionic liquids, with phosphonium and ammonium cations, towards several environmental...  相似文献   
999.
The disinfection of drinking water is an important public health service that generates high quality, safe and palatable tap water. The disinfection of drinking water to reduce waterborne disease was an outstanding public health achievement of the 20th century. An unintended consequence is the reaction of disinfectants with natural organic matter, anthropogenic contaminants and bromide/iodide to form disinfection by-products (DBPs). A large number of DBPs are cytotoxic, neurotoxic, mutagenic, genotoxic, carcinogenic and teratogenic. Epidemiological studies demonstrated low but significant associations between disinfected drinking water and adverse health effects. The distribution of DBPs in disinfected waters has been well defined by advances in high precision analytical chemistry. Progress in the analytical biology and toxicology of DBPs has been forthcoming. The objective of this review was to provide a detailed presentation of the methodology for the quantitative, comparative analyses on the induction of cytotoxicity and genotoxicity of 103 DBPs using an identical analytical biological platform and endpoints. A single Chinese hamster ovary cell line was employed in the assays. The data presented are derived from papers published in the literature as well as additional new data and represent the largest direct quantitative comparison on the toxic potency of both regulated and emerging DBPs. These data may form the foundation of novel research to define the major forcing agents of DBP-mediated toxicity in disinfected water and may play an important role in achieving the goal of making safe drinking water better.  相似文献   
1000.
The formation and concentration of disinfection by-products (DBPs) in pool water and the ambient air vary according to the type of water treatment process used. This exploratory study was aimed at investigating the short-term impact of modifications of the water treatment process on traditional DBP levels (e.g., trihalomethanes (THMs), chloramines) and emerging DBPs (e.g., Halonitromethanes, Haloketones, NDMA) in swimming pool water and/or air. A sampling program was carried to understand the impact of the following changes made successively to the standard water treatment process: activation of ultraviolet (UV) photoreactor, halt of air stripping with continuation of air extraction from the buffer tank, halt of air stripping and suppression of air extraction from the buffer tank, suppression of the polyaluminium silicate sulfate (PASS) coagulant. UV caused a high increase of Halonitromethanes (8.4 fold), Haloketones (2.1 fold), and THMs in the water (1.7 fold) and, of THMs in the air (1.6 fold) and contributed to reducing the level of chloramines in the air (1.6 fold) and NDMA in the water (2.1 fold). The results highlight the positive impact of air stripping in reducing volatile contaminants. The PASS did not change the presence of DBPs, except for the THMs, which decrease slightly with the use of this coagulant. This study shows that modifications affecting the water treatment process can rapidly produce important and variable impacts on DBP levels in water and air and suggests that implementation of any water treatment process to reduce DBP levels should take into account the specific context of each swimming pool.  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