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   1609篇
  免费   17篇
  国内免费   40篇
安全科学   22篇
废物处理   108篇
环保管理   155篇
综合类   138篇
基础理论   292篇
环境理论   2篇
污染及防治   544篇
评价与监测   297篇
社会与环境   104篇
灾害及防治   4篇
  2023年   59篇
  2022年   172篇
  2021年   114篇
  2020年   25篇
  2019年   46篇
  2018年   82篇
  2017年   88篇
  2016年   108篇
  2015年   44篇
  2014年   78篇
  2013年   174篇
  2012年   74篇
  2011年   88篇
  2010年   69篇
  2009年   60篇
  2008年   71篇
  2007年   54篇
  2006年   62篇
  2005年   34篇
  2004年   23篇
  2003年   20篇
  2002年   28篇
  2001年   8篇
  2000年   7篇
  1999年   6篇
  1998年   3篇
  1997年   2篇
  1996年   6篇
  1995年   2篇
  1994年   4篇
  1993年   3篇
  1992年   3篇
  1989年   2篇
  1988年   3篇
  1985年   2篇
  1984年   2篇
  1983年   4篇
  1982年   5篇
  1979年   2篇
  1969年   1篇
  1966年   1篇
  1965年   2篇
  1964年   2篇
  1962年   2篇
  1961年   4篇
  1958年   3篇
  1957年   3篇
  1956年   2篇
  1955年   4篇
  1953年   1篇
排序方式: 共有1666条查询结果,搜索用时 31 毫秒
81.
82.
The in vitro study was carried out to examine the toxicity of four commercially used pesticides (phorate, mancozeb, chlorpyrifos, and endosulfan) at the recommended dose (1X) and higher field doses (1.5X, 2X, 2.5X, and 3X) on plant growth-promoting activities of Burkholderia sp. strain L2, isolated from pesticide-treated rhizosphere of Lycopersicon esculentum. At the recommended dose, level of toxicity of all the pesticides to phosphate solubilization activity and indole-3-acetic acid (IAA) production was less detrimental as compared to exceeding doses. At maximum dose rate of each pesticide, the percentage decrease in phosphate solubilization and IAA production over control was found in order of chlorpyrifos < mancozeb < endosulfan < phorate. Present study proves that Burkholderia sp. strain L2 could be used as a potential microbial inoculant in the agricultural soil having persistent pesticide residues.  相似文献   
83.
84.
Currently, there are limited data on the levels of perfluoroalkyl substances other than perfluorooctane sulfonic acid and perfluorooctanoic acid in the human body. Most of this information has been extracted from biological monitoring of plasma while the occurrence of perfluoroalkyl substances in other human tissues is rarely studied. The objective of the present study was to develop a physiologically based pharmacokinetic model to assess the concentration of perfluoroalkyl substances in human tissues, based on an existing model previously validated for perfluorooctane sulfonic acid and perfluorooctanoic acid. Experimental data on concentrations of perfluoroalkyl substances in human tissues from individuals in Tarragona County (Catalonia, Spain) were used to estimate the values of some distribution and elimination parameters needed for the simulation. No significant correlations were found between these parameters and the chain lengths. The model was finally validated for five perfluoroalkyl substances.  相似文献   
85.
Madhupur National Park is renowned for severe resource ownership conflicts between ethnic communities and government authorities in Bangladesh. In this study, we applied the Institutional Analysis and Development framework to identify: (i) past and present informal institutional structures within the ethnic Garo community for land resource management; (ii) the origin of the land ownership dispute; (iii) interaction mechanisms between formal and informal institutions; and (iv) change in land management authority and informal governance structures. We identify that the informal institutions of the traditional community have undergone radical change due to government interventions with implications for the regulation of land use, informal institutional functions, and joint-decision-making. Importantly, the government’s persistent denial of the role of existing informal institutions is widening the gap between government and community actors, and driving land ownership conflicts in a cyclic way with associated natural resource degradation.  相似文献   
86.
Housing is not only one of the major sources of carbon dioxide (CO2) emissions, but it has been increasingly vulnerable to climate-induced disasters, particularly those sheltering the urban poor. Both mitigation and adaptation measures are therefore required for the design and construction of low-income housing to encourage low carbon development and improve resilience to disasters. As self-help housing—the common type of housing for the urban poor in developing countries—is usually built by ordinary people with participatory approach, it is crucial to develop a low-carbon and disaster-resilient assessment tool for assisting them in making informed decisions during planning process. The objective of this article is to propose a new approach for developing a low-carbon and disaster-resilient assessment tool for self-help housing (LoDAT-SH) by combining opinions from experts and community residents to assign weights, identify indicators, and establish benchmarks with the aim to develop a simple, relevant, and practical tool for non-expert users like self-help residents. The application of the proposed methodology to a case study of a developing country, Thailand, shows the ability of LoDAT-SH, which contains 45 indicators in the four categories of low carbon development, disaster resilience, community participation, and financial consideration, in enabling self-help residents to assess the performance of their housing design, identify potential measures to create a low-carbon and disaster-resilient housing, and prioritize such actions. To support the creation of a low-carbon and disaster-resilient housing as the mitigation and adaptation strategy for urban development at the global level, the study suggests that the methodology of LoDAT-SH should be replicated to develop a more comprehensive assessment tool applicable for the use in self-help housing design in other developing countries, which will house about 900 million of the urban poor by 2020.  相似文献   
87.
88.
Abstract

A simple analytical procedure for the determination of Aroclor 1260 in cattle adipose tissue is described. The polychlorinated biphenyls residues are extracted from the tissue using a soxhlet extractor and the extracts are cleaned up using a florisil SEP‐PAK cartridge. The residues are detected using a gas chromatograph equipped with an electron capture detector. The effect of extraction time of the Aroclor 1260 residues from the tissue has been investigated and a period of four hours is found to give satisfactory percent recoveries. Greater than 85 percent recoveries were obtained from adipose tissue spiked with Aroclor 1260. The method can be used to detect Aroclor 1260 residue levels as low as 0.10 parts per million.

The method was used to analyze thirty‐one cattle adipose tissue samples out of which twenty‐six samples were taken from cattle suspected of exposure to a pasture containing electrical transformers and capacitors containing Aroclor 1260. Five control samples were collected from cattle with no known exposure. All twenty‐six samples were found to contain non‐detectable Aroclor 1260 residues.  相似文献   
89.
90.
Size-segregated aerosol samples (PM2.5 and PM10) were collected during Jan–Dec-2007 from a high-altitude site located in a semi-arid region (Mt. Abu, 24.6 °N, 72.7 °E, 1680 m asl) in order to asses the temporal variability in the abundance of atmospheric mineral dust and its elemental composition over western India. The mass concentrations of fine (PM2.5) and coarse (PM10–2.5) mode aerosols varied from 1.6 to 46.1 and 2.3 to 102 μg m?3 respectively over the annual seasonal cycle; with dominant and uniform contribution of mineral dust (60–80%) in the coarse mode relative to large temporal variability (11–75%) observed in the fine mode. The coarse mass fraction shows a characteristic increase with the wind speed during summer months (Mar to Jun); whereas fine aerosol mass and its elemental composition exhibit conspicuous temporal pattern associated with north-easterlies during wintertime (Oct–Feb). The Fe/Al weight ratio in PM2.5 ranges from 0.5 to 1.0 during winter months. The relative enrichment of Fe in fine mode, compared to the crustal ratio of 0.44, is attributed to the down-wind advective transport of combustion products derived from large-scale biomass burning, industrial and automobile emission sources located in the Indo-Gangetic Plain (northern India). In contrast, Ca/Al and Mg/Al weight ratios show relative enrichment of Ca and Mg in the coarse mode; indicating their dominant contribution from carbonate minerals. This has implication to efficient neutralization of atmospheric acidic species (SO42? and NO3?) by mineral dust over western India.  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