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   25678篇
  免费   854篇
  国内免费   5844篇
安全科学   1402篇
废物处理   1748篇
环保管理   2582篇
综合类   9982篇
基础理论   5617篇
环境理论   4篇
污染及防治   7151篇
评价与监测   1690篇
社会与环境   1500篇
灾害及防治   700篇
  2024年   33篇
  2023年   273篇
  2022年   843篇
  2021年   749篇
  2020年   632篇
  2019年   527篇
  2018年   2053篇
  2017年   2100篇
  2016年   1849篇
  2015年   1052篇
  2014年   1335篇
  2013年   1737篇
  2012年   1912篇
  2011年   2761篇
  2010年   1786篇
  2009年   1645篇
  2008年   2045篇
  2007年   2208篇
  2006年   855篇
  2005年   622篇
  2004年   507篇
  2003年   613篇
  2002年   568篇
  2001年   425篇
  2000年   441篇
  1999年   427篇
  1998年   411篇
  1997年   394篇
  1996年   357篇
  1995年   262篇
  1994年   209篇
  1993年   188篇
  1992年   148篇
  1991年   113篇
  1990年   74篇
  1989年   41篇
  1988年   37篇
  1987年   16篇
  1986年   20篇
  1985年   14篇
  1984年   28篇
  1983年   21篇
  1982年   15篇
  1981年   13篇
  1978年   2篇
  1975年   2篇
  1974年   2篇
  1972年   2篇
  1957年   1篇
  1935年   2篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Environmental Science and Pollution Research - The existing literature on the environmental Kuznets curve (EKC) fails to investigate the spatial attribute of the “pollution halo” effect...  相似文献   
2.
Environmental Science and Pollution Research - A mechanical harvesting technology based on coupling flocculation with a rotary drum filter (RDF, 35-μm) was applied to remove cyanobacterial...  相似文献   
3.
Environmental Science and Pollution Research - Growing environmental pressure urges China to develop in a sustainable and low carbon way, and thus China strives to achieve a carbon peak by 2030 and...  相似文献   
4.
Environmental Science and Pollution Research - At present, the contradiction between survival and ecology necessitates the integration of crop planting, chemical fertilizer application, and...  相似文献   
5.
Environmental Science and Pollution Research - Hydrothermal liquefaction (HTL) of biomass used HTL reaction under high temperature and pressure to produce bio-oil. This technology is considered as...  相似文献   
6.
Environmental Science and Pollution Research - The impact of high concentrations of air pollution on COVID-19 has been a major air quality and life safety issue in recent studies. This study aimed...  相似文献   
7.
The chemical recycling of cellulosic fibres may represent a next-generation fibre–fibre recycling system for cotton textiles, though remaining challenges include how to accommodate fibre blends, dyes, wrinkle-free finishes, and other impurities from finishing. These challenges may disrupt the regeneration process steps and reduce the fibre quality. This study examines the impact on regenerated viscose fibre properties of a novel alkaline/acid bleaching sequence to strip reactive dyes and dimethyloldihydroxyethyleneureas (DMDHEU) wrinkle-free finish from cotton textiles. Potentially, such a bleaching sequence could advantageously be integrated into the viscose process, reducing the costs and environmental impact of the product. The study investigates the spinning performance and mechanical properties (e.g., tenacity and elongation) of the regenerated viscose fibres. The alkaline/acid bleaching sequence was found to strip the reactive dye and DMDHEU wrinkle-free finish from the cotton fabric, so the resulting pulp could successfully be spun into viscose fibres, though the mechanical properties of these fibres were worse than those of commercial viscose fibres. This study finds that reactive dyes and DMDHEU wrinkle-free finish affect the viscose dope quality and the regeneration performance. The results might lead to progress in overcoming quality challenges in cellulosic chemical recycling.  相似文献   
8.
The discovery of ordered mesoporous materials in 1992 by Mobil Oil Corporation scientists has opened great opportunities for new applications in many emerging fields such as heterogeneous catalysis, biocatalysis, energy conversion, biosensors, photocatalytic devices and environmental technologies. Porous materials are grouped by the International Union of Pure and Applied Chemistry (IUPAC) into three classes according to their pore diameter: microporous (<?2 nm), mesoporous (2–50 nm) and macroporous (>?50 nm). One of the most versatile methods for the preparation of those materials is the soft template approach which combines the sol–gel process with molecular self-assembly. While the micelles formed by ionic or nonionic surfactants, as well as amphiphilic polymers, have been extensively used as templates, the supramolecular assemblies formed between cyclodextrins and block copolymers have been less investigated, despite their large chemical and structural diversity. This review article focuses mainly on nanostructured porous inorganic materials derived from cyclodextrins or cyclodextrin-based assemblies. More than 100 references are described and discussed, in which we look both at their synthesis and characterization, as well as their applications in the emerging fields of heterogeneous catalysis and photocatalysis. A special attention is paid to the evaluation of the critical parameters that need to be controlled for improving their (photo) catalytic performances.  相似文献   
9.
The CO2 absorption capacities of potassium glycinate, potassium sarcosinate (choline, proline), mono-ethanolamine (MEA), and tri-ethanolamine were evaluated to find the optimal absorbent for separating CO2 from gaseous products by a CO2 purification process. The absorption loading, desorption efficiency, cost, and environmental tolerance were assessed to select the optimal absorbent. MEA was found to be the optimum absorbent for separating the CO2 and H2 mixture in gaseous product. The maximum absorption loading rate was 0.77 mol CO2 per mol MEA at temperature of 20°C and absorbent concentration of 2.5 mol/L, whereas desorption efficiency was 90% by heating for 3 h at 130°C. MEA was found to be an optimal absorbent for the purification process of CO2 during gaseous production.  相似文献   
10.
Environmental Science and Pollution Research - Phosphorus is an&nbsp;essential macro-mineral nutrient for poultry, needed for the body growth, development of bones, genomic function, good...  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