全文获取类型
收费全文 | 5934篇 |
免费 | 359篇 |
国内免费 | 1333篇 |
专业分类
安全科学 | 389篇 |
废物处理 | 318篇 |
环保管理 | 567篇 |
综合类 | 2633篇 |
基础理论 | 1158篇 |
环境理论 | 1篇 |
污染及防治 | 1704篇 |
评价与监测 | 402篇 |
社会与环境 | 317篇 |
灾害及防治 | 137篇 |
出版年
2024年 | 17篇 |
2023年 | 102篇 |
2022年 | 253篇 |
2021年 | 202篇 |
2020年 | 193篇 |
2019年 | 169篇 |
2018年 | 257篇 |
2017年 | 230篇 |
2016年 | 222篇 |
2015年 | 247篇 |
2014年 | 338篇 |
2013年 | 566篇 |
2012年 | 411篇 |
2011年 | 450篇 |
2010年 | 385篇 |
2009年 | 415篇 |
2008年 | 397篇 |
2007年 | 352篇 |
2006年 | 303篇 |
2005年 | 250篇 |
2004年 | 228篇 |
2003年 | 244篇 |
2002年 | 168篇 |
2001年 | 230篇 |
2000年 | 159篇 |
1999年 | 102篇 |
1998年 | 96篇 |
1997年 | 74篇 |
1996年 | 74篇 |
1995年 | 65篇 |
1994年 | 44篇 |
1993年 | 38篇 |
1992年 | 51篇 |
1991年 | 26篇 |
1990年 | 29篇 |
1989年 | 21篇 |
1988年 | 12篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 19篇 |
1984年 | 17篇 |
1983年 | 11篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1975年 | 9篇 |
1974年 | 12篇 |
1973年 | 11篇 |
1972年 | 13篇 |
排序方式: 共有7626条查询结果,搜索用时 15 毫秒
851.
Wet air oxidation of a prepared reactive dye solution was performed to assess the efficacy of CoAlPO(4)-5 and CeO(2) as catalysts in the reaction. Via adsorption and oxidation of dye, CoAlPO(4)-5 effectively decreased American Dye Manufacturers Institute and chemical oxygen demand (COD) values in the dye solution. At a reaction temperature of 135 degrees C and an applied pressure of 1.0 MPa, color and COD removal were as high as 95% and 90%, respectively, after 2 h. Active sites on the outer surface of CoAlPO(4)-5 are responsible for adsorption and decomposition of dye while active sites in the pores dominate further destruction and oxidation of intermediate products. Since the outer surface only represents a minor part of the total surface, the color removal does not increase appreciably with loading of CoAlPO(4)-5. The CeO(2) catalyst, calcined from cerium chloride under high thermal impact (type A CeO(2)) was very effective in removing color and COD from the solution. This catalyst demonstrated near 100% color removal at temperatures above 135 degrees C and the COD removal could be above 95% at 165 degrees C. With both CoAlPO(4)-5 and CeO(2) catalysts, COD rose and then fell back during the reaction, a feature typical of a consecutive reaction. In contrast to prepared CeO(2), a commercial CeO(2) did not exhibit any catalytic ability for the removal of color and COD. The durability of both CoAlPO(4)-5 and prepared CeO(2) is considered to be fair. 相似文献
852.
853.
本文介绍了球团竖炉的烟尘排放特性 ,分析了烟尘回收效益及脱硫、除尘、除雾一体化技术设备 ,该技术设备是一种紧凑合理、高效耐用、性价比高、管理方便、适合国情的大气环境净化技术设备 相似文献
854.
855.
856.
添加剂升温烧蚀法在制备新型介孔水环境净化材料中的应用 总被引:2,自引:0,他引:2
首次探索了一种破坏式造孔与有机复合相结合的新方法以制备介孔复合水环境净化材料,使最终产品成为一种具有广谱孔结构分布的复合环境材料。详细介绍了该方法的第二步工艺即添加剂升温烧蚀法,在优化后的最佳条件下,产品的孔径得到了进一步扩大,其中部分孔道直径可达至介孔级,同时材料的表面得到了进一步活化。经此步工艺后,所制备的中间产品染料吸附量是原材料的194倍,是酸洗刻蚀后产品的122倍;24h吸湿率是原材料的38倍,是酸洗刻蚀后产品的19倍。 相似文献
857.
Yang Y Tao S Wong PK Hu JY Guo M Cao HY Coveney RM Zuo Q Li BG Liu WX Cao J Xu FL 《Chemosphere》2005,60(6):753-761
The dynamic exposures to HCHs of individuals born between the years 1913 and 1993 in Tianjin have been simulated by connecting a fugacity model (IV) with a multimedia exposure model. Ingestion is the most important pathway for human beings to take up HCHs, and concentrations in the human body correlate with body weight changes. Accumulations of HCHs were derived assuming that the degradation in human body behaved linearly. The health risk of exposure to HCHs was measured using cancer risk and loss of life expectancy (LLE), and LLE was modified from its original definition to incorporate a dynamic calculation that takes variances in exposure into account. Monte-Carlo simulations were run to analyze the uncertainties of the model. 相似文献
858.
859.
活性炭纤维吸附废水中对硝基苯酚及其脱附研究 总被引:8,自引:0,他引:8
采用新型高效吸附剂——活性炭纤维吸附废水中对硝基苯酚,对其吸附和脱附影响因素进行了较详细的研究,确定了最佳工艺参数,并对动态吸附一脱附进行了稳定性实验。在最佳的吸附条件下,装填4g活性炭纤维可处理含对硝基苯酚1000mg/L的废水1400mL,出水对硝基苯酚浓度〈2mg/L,达到国家综合污水一级排放标准,活性炭纤维有效吸附量可达349.87mg/g。在最佳脱附条件下,脱附率〉99%,并可从高浓度脱附液中回收对硝基苯酚。稳定性实验表明,吸附-脱附性能稳定,采用活性炭纤维吸附处理对硝基苯酚废水是一种行之有效的处理方法。 相似文献
860.
A study of using dual membrane technologies, microfiltration (MF) and reverse osmosis (RO), for reclaiming blowdown of the cooling tower was conducted at ZJK power plant, Hebei province, China. The study shows that the combined MF-RO system can effectively reduce water consumption in the power industry. The results indicate that MF process is capable of producing a filtrate suitable for RO treatment and achieving a silt density index (SDI) less than 2, turbidity of 0.2 NTU. The water quality of RO effluent is very good with an average conductivity of about 40 micros/cm and rejection of 98%. The product water is suitable for injection into the cooling tower to counteract with cooling water intrusion. After adopting this system, water-saving effectiveness as expressed in terms of cycles of concentration could be increased from 2.5-2.8 times to 5 times. 相似文献