全文获取类型
收费全文 | 7855篇 |
免费 | 387篇 |
国内免费 | 440篇 |
专业分类
安全科学 | 1687篇 |
废物处理 | 161篇 |
环保管理 | 875篇 |
综合类 | 4585篇 |
基础理论 | 244篇 |
污染及防治 | 422篇 |
评价与监测 | 452篇 |
社会与环境 | 123篇 |
灾害及防治 | 133篇 |
出版年
2024年 | 23篇 |
2023年 | 67篇 |
2022年 | 91篇 |
2021年 | 144篇 |
2020年 | 148篇 |
2019年 | 155篇 |
2018年 | 81篇 |
2017年 | 117篇 |
2016年 | 208篇 |
2015年 | 275篇 |
2014年 | 531篇 |
2013年 | 347篇 |
2012年 | 404篇 |
2011年 | 468篇 |
2010年 | 345篇 |
2009年 | 341篇 |
2008年 | 372篇 |
2007年 | 501篇 |
2006年 | 433篇 |
2005年 | 354篇 |
2004年 | 311篇 |
2003年 | 389篇 |
2002年 | 316篇 |
2001年 | 269篇 |
2000年 | 245篇 |
1999年 | 249篇 |
1998年 | 232篇 |
1997年 | 217篇 |
1996年 | 218篇 |
1995年 | 192篇 |
1994年 | 147篇 |
1993年 | 121篇 |
1992年 | 84篇 |
1991年 | 102篇 |
1990年 | 97篇 |
1989年 | 84篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有8682条查询结果,搜索用时 93 毫秒
61.
This article describes the integrated modeling approach for planning the size and the operation of constructed wetlands for
maximizing retention of nonpoint source pollutant loads and reservoir water-quality improvement at a catchment scale. The
experimental field-scale wetland systems (four sets, 0.88 ha each) have been in operation since 2002, where water depth was maintained
at 30–50 cm and hydraulic loading rate was at 6.3–18.8 cm/day. The wetland system was found to be adequate for treating polluted
stream water with stable removal e ciency even during the winter. The integrated modeling system (modified-BASINS) was applied to
the Seokmoon estuarine reservoir watershed and calibrated with monitoring data from constructed wetland, stream, and reservoir. The
calibrated integrated modeling system estimated that constructing wetlands on 0.5% (about 114 ha) of the watershed area at the mouth
of reservoir could reduce 11.61% and 13.49% of total external nitrogen and phosphorus loads, respectively. It also might improve the
nitrogen and phosphorus concentration of the reservoir by 9.69% and 16.48%, respectively. The study suggested that about 0.1%–1.0%
of the watershed area should be allocated for constructed wetland to meet specified water-quality standards for the estuarine reservoir
at the polder area where land use planning is relatively less complicated. 相似文献
62.
Evaluation of mercury speciation and removal through air pollution control
devices of a 190 MW boiler 总被引:1,自引:0,他引:1
Chengli Wu Yan Cao Zhongbing Dong Chinmin Cheng Hanxu Li Weiping Pan 《环境科学学报(英文版)》2010,22(2):277-282
Air pollution control devices (APCDs) are installed at coal-fired power plants for air pollutant regulation. Selective catalytic reduction
(SCR) and wet flue gas desulfurization (FGD) systems have the co-benefits of air pollutant and mercury removal. Configuration
and operational conditions of APCDs and mercury speciation a ect mercury removal e ciently at coal-fired utilities. The Ontario
Hydro Method (OHM) recommended by the U.S. Environmental Protection Agency (EPA) was used to determine mercury speciation
simultaneously at five sampling locations through SCR-ESP-FGD at a 190 MW unit. Chlorine in coal had been suggested as a factor
a ecting the mercury speciation in flue gas; and low-chlorine coal was purported to produce less oxidized mercury (Hg2+) and more
elemental mercury (Hg0) at the SCR inlet compared to higher chlorine coal. SCR could oxidize elemental mercury into oxidized
mercury when SCR was in service, and oxidation e ciency reached 71.0%. Therefore, oxidized mercury removal e ciency was
enhanced through a wet FGD system. In the non-ozone season, about 89.5%–96.8% of oxidized mercury was controlled, but only
54.9%–68.8% of the total mercury was captured through wet FGD. Oxidized mercury removal e ciency was 95.9%–98.0%, and there
was a big di erence in the total mercury removal e ciencies from 78.0% to 90.2% in the ozone season. Mercury mass balance was
evaluated to validate reliability of OHM testing data, and the ratio of mercury input in the coal to mercury output at the stack was from
0.84 to 1.08. 相似文献
63.
64.
65.
中国“十一五”规划纲要提出,“十一五”期间单位国内生产总值能耗降低20%左右,主要污染物排放总量减少10%。实现“十一五”节能和减排目标,是政府提出的一项硬性任务,行政约束性比较强。 相似文献
66.
我国湖泊富营养化防治与控制策略研究进展 总被引:25,自引:6,他引:19
随着全球人口的不断增加,工业化、城市化以及农业现代化的快速推进,湖泊富营养化问题已日益成为全球性的水环境污染问题。近年来,我国经济发展提速,资源利用强度加大,导致湖泊氮、磷营养盐严重富集,某些湖泊生态系统结构遭受破坏,功能紊乱,一些区域的湖泊蓝藻水华频繁爆发,湖泊富营养化呈现迅猛发展的趋势,并对区域经济发展与生产、生活用水保障带来挑战。尽管为了防控湖泊富营养化,我国各级政府投入了大量人力与物力,但在一些湖泊富营养化频繁区,一些防治与控制措施还没有收到理想而满意的效果。文章在综述国内外湖泊富营养化防治与控制策略研究的基础上,阐述了我国在富营养化研究方面存在的主要问题,提出了我国湖泊富营养化分区、分类控制的新思路。 相似文献
67.
68.
69.
70.