全文获取类型
收费全文 | 2873篇 |
免费 | 444篇 |
国内免费 | 916篇 |
专业分类
安全科学 | 413篇 |
废物处理 | 88篇 |
环保管理 | 288篇 |
综合类 | 2050篇 |
基础理论 | 436篇 |
环境理论 | 1篇 |
污染及防治 | 444篇 |
评价与监测 | 116篇 |
社会与环境 | 172篇 |
灾害及防治 | 225篇 |
出版年
2024年 | 16篇 |
2023年 | 76篇 |
2022年 | 175篇 |
2021年 | 183篇 |
2020年 | 214篇 |
2019年 | 167篇 |
2018年 | 149篇 |
2017年 | 195篇 |
2016年 | 143篇 |
2015年 | 202篇 |
2014年 | 215篇 |
2013年 | 252篇 |
2012年 | 282篇 |
2011年 | 269篇 |
2010年 | 250篇 |
2009年 | 231篇 |
2008年 | 229篇 |
2007年 | 198篇 |
2006年 | 191篇 |
2005年 | 136篇 |
2004年 | 97篇 |
2003年 | 75篇 |
2002年 | 64篇 |
2001年 | 43篇 |
2000年 | 41篇 |
1999年 | 33篇 |
1998年 | 27篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 10篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1984年 | 4篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1961年 | 2篇 |
1959年 | 1篇 |
1932年 | 1篇 |
排序方式: 共有4233条查询结果,搜索用时 908 毫秒
321.
322.
Pamornrat Kueseng Mathieu L. Noir Bo Mattiasson Panote Thavarungkul Proespichaya Kanatharana 《Journal of environmental science and health. Part. B》2013,48(8):772-780
A molecularly imprinted polymer (MIP) for atrazine was synthesized by non-covalent method. The binding capacity of MIP was 1.00 mg g? 1 polymer. The selectivity and recovery were investigated with various pesticides which are mostly, found in the environment, for both similar and different chemical structure of atrazine. The competitive recognition between atrazine and structurally similar compounds was evaluated and it was found that the system provided highest recovery and selectivity for atrazine while low recovery and selectivity were obtained for the other compounds. The highest recovery was obtained from MIP compared with non-imprinted polymer (NIP), a commercial C18 and a granular activated carbon (GAC) sorbent. The method provided high recoveries ranged from 94 to 99% at two spiked levels with relative standard deviations less than 2%. The lower detection limit of the method was 80 ng L? 1. This method was successfully applied for analysis of environmental water samples. 相似文献
323.
Stakeholders on Meat Production, Meat Consumption and Mitigation of Climate Change: Sweden as a Case
Henrik Lerner Bo Algers Stefan Gunnarsson Anders Nordgren 《Journal of Agricultural and Environmental Ethics》2013,26(3):663-678
In this paper we analyse and discuss the views of Swedish stakeholders on how to mitigate climate change to the extent it is caused by meat production. The stakeholders include meat producer organisations, governmental agencies with direct influence on meat production, political parties as well as non-governmental organisations. Representatives of twelve organisations were interviewed. Several organisations argued against the mitigation option of reducing beef production despite the higher greenhouse gas intensity of beef compared to pork and chicken meat (according to life cycle analysis). Regarding feed production some organisations proposed use of the best available industrial fertilizers, others were against all use of such fertilizers. Several organizations suggested domestic production of more protein-rich fodder and use of manure for biogas production. Regarding meat consumption the focus was on throwing away less food as waste and on eating less meat but the best (most climate friendly) meat, which was considered to be Swedish meat in contrast to imported meat. There was agreement on many issues. Most disagreement was found regarding political steering. We find many of the stakeholders’ mitigation proposals regarding meat production and consumption acceptable. However, we are to some extent critical to their defence of Swedish beef production. We also point out certain problems with the suggestion to reduce consumption of imported meat but not of domestically produced meat. 相似文献
324.
Shuting ZHANG Bo WEI Xin YU Bing LIU Zhuoying WU Li GU 《Frontiers of Environmental Science & Engineering in China》2010,4(4):459-465
The biologic activated carbon (BAC) process is widely used in drinking water treatments. A comprehensive molecular analysis
of the microbial community structure provides very helpful data to improve the reactor performance. However, the bottleneck
of deoxyribonucleic acid (DNA) extraction from BAC attached biofilm has to be solved since the conventional procedure was
unsuccessful due to firm biomass attachment and adsorption capacity of the BAC granules. In this study, five pretreatments
were compared, and adding skim milk followed by ultrasonic vibration was proven to be the optimal choice. This protocol was
further tested using the vertical BAC samples from the full-scale biofilter of Pinghu Water Plant. The results showed the
DNAyielded a range of 40 μg·g−1 BAC (dry weight) to over 100 μg·g−1 BAC (dry weight), which were consistent with the biomass distribution. All results suggested that the final protocol could
produce qualified genomic DNA as a template from the BAC filter for downstream molecular biology researches. 相似文献
325.
聚合氯化铝与三氯化铁混凝剂在常规水处理中的运用 总被引:3,自引:0,他引:3
通过聚合氯化铅与三氯化铁在常规水处理的生产性实验,从经济成本、水质指标和实际使用存在的问题对其进行分析比较,并比较了两种混凝剂在常规水处理中的优缺点。 相似文献
326.
以意大利的FACE(Free atmospheric CO2 enrichment)长期定位试验区和大气环境控制装置为研究对象,用化学分步酸提法将土壤有机质分离为活性库、慢库和惰性库,并培养测定土壤有机氮的矿化率,研究人工模拟大气CO2富集、施氮肥及植株类型对土壤有机质库及激发效应的影响.第一茬(POP FACE)试验产生了激发效应.但第二茬(Euro FACE)试验CO2处理区的总碳增加最显著高于对照处理区.即激发效应终止.主成分分析显示,有效氮的矿化水平已成为有机质降解的制约因素.据此推断,试验区巾活性碳和有效氮控制的激发效应阶段转变为氮利用受限所引起的碳积累阶段.CO2富集对N矿化率、慢库和惰性库均无显著性影响.研究结果表明,土壤的激发效应不仅受有机碳的活性库制约,氮的矿化率也是影响其发生的关键因子之一. 相似文献
327.
Changes of protists, which were categorized into different functional groups primarily according to their feeding habits, in two full-scale municipal wastewater treatment systems experiencing sludge bulking were investigated over a period of 14 months. Protist biomass represented 3.7% to 5.2% of total biomass on average under normal sludge conditions, and the percentage increased significantly (p < 0.05) under sludge bulking conditions. The biomass of Chilodonella spp., capable of eating filamentous bacteria, tended to decrease in both systems when sludge bulking occurred, showing that the abnormal growth of filamentous bacteria did not lead to a biomass bloom of this group of protists. On the other hand, the bactivorous protists represented more than 96% of total protist biomass, and the biomass of this group, particularly the attached ciliates, increased significantly (p < 0.05) when sludge bulking occurred. The significant increase of the attached ciliates may have possibly facilitated the growth of filamentous bacteria through selectively preying on non-filamentous bacteria and further exacerbated sludge bulking. The redundancy analysis and correlation analysis results showed that the biomass changes of the attached ciliates were primarily related to the sludge volume index and to some extent related to five-day biochemical oxygen demand loading and hydraulic retention time. 相似文献
328.
329.
分析当前通风隔声窗的现状,以及通风隔声窗发展中的几个关键点,即:安静、节能、智能、清新空气、美观;结合正升声学公司开发的通风隔声窗产品讨论通风隔声窗在未来住宅建筑中的应用。 相似文献
330.