全文获取类型
收费全文 | 20222篇 |
免费 | 278篇 |
国内免费 | 184篇 |
专业分类
安全科学 | 633篇 |
废物处理 | 822篇 |
环保管理 | 2999篇 |
综合类 | 3051篇 |
基础理论 | 5571篇 |
环境理论 | 12篇 |
污染及防治 | 4963篇 |
评价与监测 | 1346篇 |
社会与环境 | 1140篇 |
灾害及防治 | 147篇 |
出版年
2023年 | 106篇 |
2022年 | 176篇 |
2021年 | 156篇 |
2020年 | 157篇 |
2019年 | 170篇 |
2018年 | 311篇 |
2017年 | 358篇 |
2016年 | 489篇 |
2015年 | 371篇 |
2014年 | 600篇 |
2013年 | 1568篇 |
2012年 | 711篇 |
2011年 | 978篇 |
2010年 | 806篇 |
2009年 | 814篇 |
2008年 | 915篇 |
2007年 | 940篇 |
2006年 | 805篇 |
2005年 | 701篇 |
2004年 | 698篇 |
2003年 | 650篇 |
2002年 | 626篇 |
2001年 | 730篇 |
2000年 | 567篇 |
1999年 | 326篇 |
1998年 | 240篇 |
1997年 | 262篇 |
1996年 | 267篇 |
1995年 | 307篇 |
1994年 | 304篇 |
1993年 | 247篇 |
1992年 | 249篇 |
1991年 | 225篇 |
1990年 | 237篇 |
1989年 | 225篇 |
1988年 | 182篇 |
1987年 | 202篇 |
1986年 | 190篇 |
1985年 | 196篇 |
1984年 | 195篇 |
1983年 | 187篇 |
1982年 | 179篇 |
1981年 | 162篇 |
1980年 | 145篇 |
1979年 | 143篇 |
1978年 | 128篇 |
1977年 | 128篇 |
1976年 | 95篇 |
1974年 | 94篇 |
1973年 | 98篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
681.
Fabiano A. N. Fernandes Ronier M. Lopes Marina P. Mercado Evne S. Siqueira 《International Journal of Green Energy》2016,13(4):417-423
This article focuses on the optimization of the production of fatty acid ethyl esters from soybean oil using CaO-based heterogeneous catalysts. Three different catalytic promoters were evaluated: Magnesium, zinc, and potassium. The reaction has evaluated the promoter content (promoter to calcium molar ratio), catalyst load, alcohol to oil molar ratio, and temperature. Response surface methodology (RSM) was used to evaluate the influence of each variable on the yield of biodiesel. The addition of K2O or MgO in the catalyst has enhanced the yield in fatty acid ethyl esters, while the use of ZnO as a promoter was not successful. 相似文献
682.
Protected areas’ role in climate-change mitigation 总被引:1,自引:0,他引:1
683.
David M. Oliver Nick D. Hanley Melanie van Niekerk David Kay A. Louise Heathwaite Sharyl J. M. Rabinovici Julie L. Kinzelman Lora E. Fleming Jonathan Porter Sabina Shaikh Rob Fish Sue Chilton Julie Hewitt Elaine Connolly Andy Cummins Klaus Glenk Calum McPhail Eric McRory Alistair McVittie Amanna Giles Suzanne Roberts Katherine Simpson Dugald Tinch Ted Thairs Lisa M. Avery Andy J. A. Vinten Bill D. Watts Richard S. Quilliam 《Ambio》2016,45(1):52-62
The use of molecular tools, principally qPCR, versus traditional culture-based methods for quantifying microbial parameters (e.g., Fecal Indicator Organisms) in bathing waters generates considerable ongoing debate at the science–policy interface. Advances in science have allowed the development and application of molecular biological methods for rapid (~2 h) quantification of microbial pollution in bathing and recreational waters. In contrast, culture-based methods can take between 18 and 96 h for sample processing. Thus, molecular tools offer an opportunity to provide a more meaningful statement of microbial risk to water-users by providing near-real-time information enabling potentially more informed decision-making with regard to water-based activities. However, complementary studies concerning the potential costs and benefits of adopting rapid methods as a regulatory tool are in short supply. We report on findings from an international Working Group that examined the breadth of social impacts, challenges, and research opportunities associated with the application of molecular tools to bathing water regulations. 相似文献
684.
Marjut Rajasilta Mikael Elfving Jari Hänninen Päivi Laine Ilppo Vuorinen Jorma Paranko 《Ambio》2016,45(2):205-214
685.
Highly erratic rainfall patterns in northern Benin complicate the ability of rural farmers to engage in subsistence agriculture. This research explores gender-specific responses to climate variability in the context of agrarian Benin through a household survey (n = 260) and an experimental gaming exercise among a subset of the survey respondents. Although men and women from the sample population are equally aware of climate variability and share similar coping strategies, their specific land-use strategies, preferences, and motivations are distinct. Over the long term, these differences would likely lead to dissimilar coping strategies and vulnerability to the effects of climate change. Examination of gender-specific land-use responses to climate change and anticipatory learning can enhance efforts to improve adaptability and resilience among rural subsistence farmers. 相似文献
686.
David A. Ross Héctor M. Guzmán Vincent J. Van Hinsberg Catherine Potvin 《Journal of environmental science and health. Part. B》2016,51(10):675-687
Concentrations of eight elements were measured in Chelonia mydas and Lepidochelys olivacea eggs collected along the Pacific coast of Panama. Manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), and mercury (Hg) concentrations were similar to previous reports of these species from around the world, while lead (Pb) was lower than previous reports. Cd posed the highest health risk to people who regularly eat the eggs, with average consumption rates leading to target hazard quotients (THQ) of up to 0.35 ± 0.15. Our conclusions indicate that current turtle egg consumption in isolated, coastal Pacific communities may pose a health concern for young children, and that youth and young adults should limit their consumption of turtle eggs to reduce their total intake of nonessential metals. 相似文献
687.
Parise Henry Olufunmilayo Owopetu Demilade Adisa Thao Nguyen Kevin Anthony David Ijoni-Animadu 《Journal of environmental science and health. Part. B》2016,51(8):546-552
The free living nematode Caenorhabditis elegans is a proven model organism for lipid metabolism research. Total lipids of C. elegans were extracted using chloroform and methanol in 2:1 ratio (v/v). Fatty acids composition of the extracted total lipids was converted to their corresponding fatty acids methyl esters (FAMEs) and analyzed by gas chromatography/accurate mass quadrupole time of flight mass spectrometry using both electron ionization and chemical ionization techniques. Twenty-eight fatty acids consisting of 12 to 22 carbon atoms were identified, 65% of them were unsaturated. Fatty acids containing 12 to17 carbons were mostly saturated with stearic acid (18:0) as the major constituent. Several branched-chain fatty acids were identified. Methyl-14-methylhexadecanoate (iso- 17:0) was the major identified branched fatty acid. This is the first report to detect the intact molecular parent ions of the identified fatty acids in C. elegans using chemical ionization compared to electron ionization which produced fragmentations of the FAMEs. 相似文献
688.
Daniel S. Read Marianne Matzke Hyun S. Gweon Lindsay K. Newbold Laura Heggelund Maria Diez Ortiz Elma Lahive David Spurgeon Claus Svendsen 《Environmental science and pollution research international》2016,23(5):4120-4128
Zinc oxide nanoparticles (ZnO NPs) are used in an array of products and processes, ranging from personal care products to antifouling paints, textiles, food additives, antibacterial agents and environmental remediation processes. Soils are an environment likely to be exposed to manmade nanoparticles due to the practice of applying sewage sludge as a fertiliser or as an organic soil improver. However, understanding on the interactions between soil properties, nanoparticles and the organisms that live within soil is lacking, especially with regards to soil bacterial communities. We studied the effects of nanoparticulate, non-nanoparticulate and ionic zinc (in the form of zinc chloride) on the composition of bacterial communities in soil with a modified pH range (from pH 4.5 to pH 7.2). We observed strong pH-dependent effects on the interaction between bacterial communities and all forms of zinc, with the largest changes in bacterial community composition occurring in soils with low and medium pH levels (pH 4.8 and 5.9). The high pH soil (pH 7.2) was less susceptible to the effects of zinc exposure. At the highest doses of zinc (2500 mg/kg dw soil), both nano and non-nano particulate zinc applications elicited a similar response in the soil bacterial community, and this differed significantly to the ionic zinc salt treatment. The results highlight the importance of considering soil pH in nanotoxicology studies, although further work is needed to determine the exact mechanisms controlling the toxicity and fate and interactions of nanoparticles with soil microbial communities. 相似文献
689.
Sana Romdhane Marion Devers-Lamrani Fabrice Martin-Laurent Christophe Calvayrac Emilie Rocaboy-Faquet David Riboul Jean-François Cooper Lise Barthelmebs 《Environmental science and pollution research international》2016,23(5):4138-4148
In this study, a bacterial strain able to use sulcotrione, a β-triketone herbicide, as sole source of carbon and energy was isolated from soil samples previously treated with this herbicide. Phylogenetic study based on16S rRNA gene sequence showed that the isolate has 100 % of similarity with several Bradyrhizobium and was accordingly designated as Bradyrhizobium sp. SR1. Plasmid profiling revealed the presence of a large plasmid (>50 kb) in SR1 not cured under nonselective conditions. Its transfer to Escherichia coli by electroporation failed to induce β-triketone degrading capacity, suggesting that degrading genes possibly located on this plasmid cannot be expressed in E. coli or that they are not plasmid borne. The evaluation of the SR1 ability to degrade various synthetic (mesotrione and tembotrione) and natural (leptospermone) triketones showed that this strain was also able to degrade mesotrione. Although SR1 was able to entirely dissipate both herbicides, degradation rate of sulcotrione was ten times higher than that of mesotrione, showing a greater affinity of degrading-enzyme system to sulcotrione. Degradation pathway of sulcotrione involved the formation of 2-chloro-4-mesylbenzoic acid (CMBA), previously identified in sulcotrione degradation, and of a new metabolite identified as hydroxy-sulcotrione. Mesotrione degradation pathway leads to the accumulation of 4-methylsulfonyl-2-nitrobenzoic acid (MNBA) and 2-amino-4 methylsulfonylbenzoic acid (AMBA), two well-known metabolites of this herbicide. Along with the dissipation of β-triketones, one could observe the decrease in 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibition, indicating that toxicity was due to parent molecules, and not to the formed metabolites. This is the first report of the isolation of bacterial strain able to transform two β-triketones. 相似文献
690.
M. Yamuna Rani D. Bhagawan V. Himabindu V. Venkateswara Reddy P. Saritha 《Environmental science and pollution research international》2016,23(10):9323-9333
This paper reports on recycling of industrial wastes (three pharmaceutical industrial sludges) into environmental friendly value-added materials. Stabilization/Solidification (S/S or bricks) process was applied to make a safer way for the utilization of pharmaceutical waste. The additives in this study include binders (cement, lime and bentonite) and strengthening material (pulverized fuel ash (PFA), silica fume and quarry dust) was used at different compositions. Bricks were cured for 28 days, and the following analysis-like compressive strength, leachability of heavy metals, mineralogical phase identity by X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and thermal behaviour by thermogravimetric-differential thermal analysis (TG-DTA) had done. All the bricks were observed to achieve the standard compressive strength as required for construction according to BIS standards. Metal concentration in the leachate has reached the dischargeable limits according to Brazilian standards. Results of this study demonstrate that production of bricks is a promising and achievable productive use of pharmaceutical sludge. 相似文献