全文获取类型
收费全文 | 1187篇 |
免费 | 9篇 |
国内免费 | 28篇 |
专业分类
安全科学 | 41篇 |
废物处理 | 80篇 |
环保管理 | 111篇 |
综合类 | 209篇 |
基础理论 | 248篇 |
环境理论 | 2篇 |
污染及防治 | 395篇 |
评价与监测 | 75篇 |
社会与环境 | 61篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 3篇 |
2022年 | 17篇 |
2021年 | 20篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 39篇 |
2017年 | 44篇 |
2016年 | 54篇 |
2015年 | 34篇 |
2014年 | 40篇 |
2013年 | 111篇 |
2012年 | 64篇 |
2011年 | 95篇 |
2010年 | 68篇 |
2009年 | 72篇 |
2008年 | 80篇 |
2007年 | 72篇 |
2006年 | 66篇 |
2005年 | 40篇 |
2004年 | 36篇 |
2003年 | 37篇 |
2002年 | 23篇 |
2001年 | 16篇 |
2000年 | 11篇 |
1999年 | 11篇 |
1998年 | 9篇 |
1997年 | 11篇 |
1996年 | 5篇 |
1995年 | 12篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1981年 | 3篇 |
1976年 | 2篇 |
1970年 | 2篇 |
1966年 | 3篇 |
1965年 | 7篇 |
1964年 | 5篇 |
1963年 | 5篇 |
1962年 | 10篇 |
1961年 | 11篇 |
1960年 | 2篇 |
1959年 | 2篇 |
1958年 | 2篇 |
1957年 | 2篇 |
1956年 | 3篇 |
1954年 | 3篇 |
1942年 | 2篇 |
1941年 | 2篇 |
排序方式: 共有1224条查询结果,搜索用时 15 毫秒
441.
Toxicity and hazard of a mixture of SSRIs to zooplankton communities evaluated in aquatic microcosms
The toxicity and hazard of a mixture of selective serotonin reuptake inhibitors (SSRIs), including fluoxetine, fluvoxamine, and sertraline, to zooplankton communities were evaluated using 120,00l outdoor microcosms. Acute (day 4) and chronic (day 35) zooplankton abundance and species richness were assessed for Rotifera, Cladocera, and Copepoda. For acute SSRI exposures, rotifers were the most sensitive zooplankton taxa to changes in abundance (predicted no effect concentration (PNEC)=19 nM); however, no effects in zooplankton species richness were observed for this treatment period. A decrease in Copepoda abundance and species richness was observed following chronic exposures of SSRIs (PNEC=9.1 nM). A 99th-centile predicted environmental concentration (PEC=0.51 nM) yielded HQs at least two orders of magnitude below 1. Therefore, mixtures of SSRIs do not appear to present a hazard to zooplankton communities at environmentally relevant concentrations. 相似文献
442.
Kumpiene J Ore S Lagerkvist A Maurice C 《Environmental pollution (Barking, Essex : 1987)》2007,145(1):365-373
The stabilization of metal contaminated soil is being tested as an alternative remediation method to landfilling. An evaluation of the changes in Cu and Pb mobility and bioavailability in soil induced by the addition of coal fly ash and natural organic matter (peat) revealed that the amount of leached Cu decreased by 98.2% and Pb by 99.9%, as assessed by a batch test. Metal leaching from the treated soil was lower by two orders of magnitude compared to the untreated soil in the field lysimeters. A possible formation of mineral Cu- and Pb-bearing phases and active surface with oxides were identified by chemical equilibrium calculations. Low metal leaching during a two-year observation period, increased seed germination rate, reduced metal accumulation in plant shoots, and decreased toxicity to plants and bacteria, thereby demonstrating this stabilization method to be a promising technique for in situ remediation of Cu and Pb contaminated soil. 相似文献
443.
444.
Environmental assessment of waste incineration in a life-cycle-perspective (EASEWASTE). 总被引:1,自引:0,他引:1
Christian Riber Gurbakhash S Bhander Thomas H Christensen 《Waste management & research》2008,26(1):96-103
A model for life-cycle assessment of waste incinerators is described and applied to a case study for illustrative purposes. As life-cycle thinking becomes more integrated into waste management, quantitative tools for assessing waste management technologies are needed. The presented model is a module in the life-cycle assessment model EASEWASTE. The module accounts for all uses of materials and energy and credits the incinerator for electricity and heat recovered. The energy recovered is defined by the user as a percentage of the energy produced, calculated on the lower heating value of the wet waste incinerated. Emissions are either process-specific (related to the amount of waste incinerated) or input-specific (related to the composition of the waste incinerated), while mass transfer to solid outputs are governed by transfer coefficients specified by the user. The waste input is defined by 48 material fractions and their chemical composition. The model was used to quantify the environmental performance of the incineration plant in Aarhus, Denmark before and after its upgrading in terms of improved flue gas cleaning and energy recovery. It demonstrated its usefulness in identifying the various processes and substances that contributed to environmental loadings as well as to environmental savings. The model was instrumental in demonstrating the importance of the energy recovery system not only for electricity but also heat from the incinerator. 相似文献
445.
Christian Riber Claus Petersen Thomas H. Christensen 《Waste management (New York, N.Y.)》2009,29(4):1251-1257
The chemical composition of Danish household waste was determined by two approaches: a direct method where the chemical composition (61 substances) of 48 material fractions was determined after hand sorting of about 20 tonnes of waste collected from 2200 households; and an indirect method where batches of 80–1200 tonnes of unsorted household waste was incinerated and the content of the waste determined from the content of the outputs from the incinerator. The indirect method is believed to better represent the small but highly contaminated material fractions (e.g., batteries) than the direct method, because of the larger quantities included and the more homogenous material to sample from. Differences between the direct and the direct methods led to corrections in the of heavy metal concentration of a few fractions.The majority of the energy content of the waste originates from organic waste like paper, cardboard and organic fractions. The single fraction contributing most to the total energy content is the non-recyclable plastic fraction, contributing 21% of the energy content and 60% of the chlorine content, although this fraction comprises less than 7% by weight. Heavy metals originate mainly from inert fractions, primarily batteries. 相似文献
446.
Long Term Effects of Acid Irrigation at the Höglwald on Seepage Water Chemistry and Nutrient Cycling
Wendelin Weis Roland Baier Christian Huber Axel Göttlein 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):211-223
In order to test the hypothesis of aluminium toxicity induced by acid deposition, an experimental acid irrigation was carried out in a mature Norway spruce stand in Southern Germany (Höglwald). The experiment comprised three plots: no irrigation, irrigation (170 mm a?1), and acid irrigation with diluted sulphuric acid (pH of 2.6–2.8). During the seven years of acid irrigation (1984–1990) water containing 0.43 molc m?2 a?1 of protons and sulphate was added with a mean pH of 3.2 (throughfall?+?acid irrigation water) compared to 4.9 (throughfall) on both control plots. Most of the additional proton input was consumed in the organic layer and the upper mineral soil. Acid irrigation resulted in a long lasting elevation of sulphate concentrations in the seepage water. Together with sulphate both aluminium and appreciable amounts of base cations were leached from the main rooting zone. The ratio between base cations (Ca?+?Mg?+?K) and aluminium was 0.79 during acid irrigation and 0.92 on the control. Neither tree growth and nutrition nor the pool of exchangeable cations were affected significantly. We conclude that at this site protection mechanisms against aluminium toxicity exist and that additional base cation runoff can still be compensated without further reduction of the supply of exchangeable base cations in the upper mineral soil. 相似文献
447.
Using a time-varying stochastic frontier model, this paper examines the technical efficiency of firms in the iron and steel industry to try to identify the factors contributing to the industry's efficiency growth. Industry observers and policymakers tend to cite most frequently three possible sources of efficiency growth: privatization; economies of scale; and vintage of equipment. Our study corroborates these factors. Based on our findings, which pertain to 52 iron and steel firms over the period of 1978–1997, privatization is likely to improve the efficiency of iron and steel firms to a great extent as evidenced in various industries. This study also provides systematic evidence that iron and steel production shows economies of scale. In addition, newer vintages of equipment are found to be closely correlated with higher levels of efficiency. This clearly indicates that investment in new plants and equipments is critical in pursuit of efficiency in the iron and steel industry. 相似文献
448.
449.
450.
The Science of Nature - 相似文献