全文获取类型
收费全文 | 34399篇 |
免费 | 335篇 |
国内免费 | 337篇 |
专业分类
安全科学 | 963篇 |
废物处理 | 1556篇 |
环保管理 | 4480篇 |
综合类 | 4629篇 |
基础理论 | 9099篇 |
环境理论 | 8篇 |
污染及防治 | 9557篇 |
评价与监测 | 2491篇 |
社会与环境 | 2053篇 |
灾害及防治 | 235篇 |
出版年
2022年 | 306篇 |
2021年 | 340篇 |
2020年 | 220篇 |
2019年 | 294篇 |
2018年 | 523篇 |
2017年 | 515篇 |
2016年 | 818篇 |
2015年 | 619篇 |
2014年 | 940篇 |
2013年 | 2949篇 |
2012年 | 1135篇 |
2011年 | 1481篇 |
2010年 | 1253篇 |
2009年 | 1324篇 |
2008年 | 1514篇 |
2007年 | 1650篇 |
2006年 | 1448篇 |
2005年 | 1204篇 |
2004年 | 1228篇 |
2003年 | 1175篇 |
2002年 | 1128篇 |
2001年 | 1457篇 |
2000年 | 1036篇 |
1999年 | 617篇 |
1998年 | 460篇 |
1997年 | 429篇 |
1996年 | 499篇 |
1995年 | 475篇 |
1994年 | 456篇 |
1993年 | 419篇 |
1992年 | 392篇 |
1991年 | 358篇 |
1990年 | 372篇 |
1989年 | 372篇 |
1988年 | 346篇 |
1987年 | 297篇 |
1986年 | 245篇 |
1985年 | 266篇 |
1984年 | 317篇 |
1983年 | 303篇 |
1982年 | 323篇 |
1981年 | 276篇 |
1980年 | 243篇 |
1979年 | 284篇 |
1978年 | 211篇 |
1977年 | 188篇 |
1976年 | 173篇 |
1975年 | 170篇 |
1973年 | 162篇 |
1972年 | 160篇 |
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
781.
Habibiandehkordi Reza Lobb David A. Sheppard Steve C. Flaten Don N. Owens Philip N. 《Environmental science and pollution research international》2017,24(22):18372-18382
Environmental Science and Pollution Research - Vegetated buffer strips (VBSs) are widely encouraged as a cost-effective strategy to address phosphorus (P) pollution associated with agricultural... 相似文献
782.
Kyoung S. Ro Patrick G. Hunt Michael A. Jackson David L. Compton Scott R. Yates Keri Cantrell SeChin Chang 《Waste management (New York, N.Y.)》2014,34(8):1520-1528
Manure-derived biochar is the solid product resulting from pyrolysis of animal manures. It has considerable potential both to improve soil quality with high levels of nutrients and to reduce contaminants in water and soil. However, the combustible gas produced from manure pyrolysis generally does not provide enough energy to sustain the pyrolysis process. Supplementing this process may be achieved with spent agricultural plastic films; these feedstocks have large amounts of available energy. Plastic films are often used in soil fumigation. They are usually disposed in landfills, which is wasteful, expensive, and environmentally unsustainable. The objective of this work was to investigate both the energetics of co-pyrolyzing swine solids with spent plastic mulch films (SPM) and the characteristics of its gas, liquid, and solid byproducts. The heating value of the product gas from co-pyrolysis was found to be much higher than that of natural gas; furthermore, the gas had no detectable toxic fumigants. Energetically, sustaining pyrolysis of the swine solids through the energy of the product gas could be achieved by co-pyrolyzing dewatered swine solids (25% m/m) with just 10% SPM. If more than 10% SPM is used, the co-pyrolysis would generate surplus energy which could be used for power generation. Biochars produced from co-pyrolyzing SPM and swine solid were similar to swine solid alone based on the surface area and the 1H NMR spectra. The results of this study demonstrated the potential of using pyrolysis technology to manage two prominent agricultural waste streams (SPM and swine solids) while producing value-added biochar and a power source that could be used for local farm operations. 相似文献
783.
For a sustainable municipal sewage sludge management, not only the available technology, but also other parameters, such as policy regulations and socio-economic issues should be taken in account. In this study, the current status of both European and Greek Legislation on waste management, with a special insight in municipal sewage sludge, is presented. A SWOT analysis was further developed for comparison of pyrolysis with incineration and gasification and results are presented. Pyrolysis seems to be the optimal thermochemical treatment option compared to incineration and gasification. Sewage sludge pyrolysis is favorable for energy savings, material recovery and high added materials production, providing a ‘zero waste’ solution. Finally, identification of challenges and barriers for sewage sludge pyrolysis deployment in Greece was investigated. 相似文献
784.
S. V. Otari R. M. Patil N. H. Nadaf S. J. Ghosh S. H. Pawar 《Environmental science and pollution research international》2014,21(2):1503-1513
A novel approach for the green synthesis of silver nanoparticles (AgNPs) from aqueous solution of AgNO3 using culture supernatant of phenol degraded broth is reported in this work. The synthesis was observed within 10 h, and AgNPs showed characteristic surface plasmon resonance around 410 nm. Spherical nanoparticles of size less than 30 nm were observed in transmission electron microscopy. X-ray diffraction pattern corresponding to 111, 200, 220, and 311 revealed the crystalline nature of the as-formed nanoparticles. It was found that the colloidal solution of AgNP suspensions exhibited excellent stability over a wide range of ionic strength, pH, and temperature. The effect of pH and ionic strength indicated that stabilization is due to electrostatic repulsion arising from the negative charge of the conjugate proteins. The AgNPs showed highly potent antimicrobial activity against Gram-positive, Gram-negative, and fungal microorganisms. The as-prepared AgNPs showed excellent catalytic activity in reduction of 4-nitrophenol to 4-aminophenol by NaBH4. By manufacturing magnetic alginate beads, the reusability of the AgNPs for the catalytic reaction has been demonstrated. 相似文献
785.
Journal of Polymers and the Environment - To optimize the phase separation temperature of poly (N-isopropylacrylamide) two monomers have been used to fabricate a series of three functional and... 相似文献
786.
787.
788.
789.
790.
R. Hickisch T. Hodgetts P. J. Johnson C. Sillero-Zubiri K. Tockner D.W. Macdonald 《Conservation biology》2019,33(5):1151-1163
Conservation planners need reliable information on spatial patterns of biodiversity. However, existing data sets are skewed because some ecosystems, taxa, and locations are underrepresented. We determined how many articles have been published in recent decades on the biodiversity of different countries and their constituent provinces. We searched the Web of Science catalogues Science Citation Index (SCI) and Social Science Citation Index (SSCI) for biodiversity-related articles published from 1993 to 2016 that included country and province names. We combined data on research publication frequency with other provincial-scale factors hypothesized to affect the likelihood of research activity (i.e., economic development, human presence, infrastructure, and remoteness). Areas that appeared understudied relative to the biodiversity expected based on site climate likely have been inaccessible to researchers for reasons, notably armed conflict. Geographic publication bias is of most concern in the most remote areas of sub-Saharan Africa and South America. Our provincial-scale model may help compensate for publication biases in conservation planning by revealing the spatial extent of research needs and the low cost of redoing this analysis annually. 相似文献