全文获取类型
收费全文 | 408篇 |
免费 | 37篇 |
国内免费 | 126篇 |
专业分类
安全科学 | 8篇 |
废物处理 | 8篇 |
环保管理 | 178篇 |
综合类 | 226篇 |
基础理论 | 50篇 |
污染及防治 | 55篇 |
评价与监测 | 22篇 |
社会与环境 | 21篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 6篇 |
2022年 | 9篇 |
2021年 | 14篇 |
2020年 | 8篇 |
2019年 | 20篇 |
2018年 | 17篇 |
2017年 | 18篇 |
2016年 | 26篇 |
2015年 | 32篇 |
2014年 | 26篇 |
2013年 | 27篇 |
2012年 | 32篇 |
2011年 | 41篇 |
2010年 | 27篇 |
2009年 | 27篇 |
2008年 | 22篇 |
2007年 | 12篇 |
2006年 | 37篇 |
2005年 | 16篇 |
2004年 | 22篇 |
2003年 | 17篇 |
2002年 | 14篇 |
2001年 | 20篇 |
2000年 | 13篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1977年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有571条查询结果,搜索用时 125 毫秒
81.
Krystyna A. Stave 《Journal of the American Water Resources Association》2001,37(5):1369-1379
ABSTRACT: This paper examines the co‐evolution of the Las Vegas, Nevada metropolitan area, Las Vegas Wash ecosystem‐a downstream riparian wetland‐and Wash management as a case of urban‐environment dynamics. Since Las Vegas Wash provides the primary drainage for Las Vegas, changes in the urban system lead to changes in the Wash and its ecosystem. The population of the drainage area has grown from approximately 1,000 people in 1900 to more than 1.3 million in 2000. This phenomenal population growth led to increased Wash flow, from less than .03 m3/sec (1 ft3/sec) to over 7.4 m3/sec (260 ft3/sec), and consequent ecological changes from a nearly dry wash to a rich wetland, and now to an eroded system. As the Wash ecosystem changed, valuation of Wash characteristics by residents and resource managers also changed, shifting the focus of management and use, which ultimately led to further ecosystem changes. Reciprocal relationships among human activity, environmental change, and management in this urban area highlight the need for a comprehensive and dynamic systems perspective and adaptive approaches in urban environmental management and make this a particularly compelling case study. This paper describes a conceptual systems framework for adaptive urban‐environment management derived from this case. 相似文献
82.
Mark M. Wilsnack David E. Welter Angela M. Montoya Jorge I. Restrepo Jayantha Obeysekera 《Journal of the American Water Resources Association》2001,37(3):655-674
ABSTRACT: As part of the Comprehensive Everglades Restoration Plan (CERP), various water supply projects have been proposed in a region located between the Miami metropolitan area and the extensive regional wetland systems that are part of the Everglades or remnant Everglades. A ground water flow model of the surficial aquifer within northern Miami‐Dade County was constructed using MODFLOW to evaluate the effects of these projects on water levels in the wetlands and the underlying surficial aquifer. The new Wetlands package was used to conjunctively simulate overland flow through these wetlands and the shallow ground water system. Comparisons of simulated to measured ground water levels and wetland stages were very satisfactory, where computed and measured water levels agreed within 0.5 ft over most of the period of record at nearly all of the monitoring sites. Temporal trends in water levels were also replicated. It was concluded that the assumptions and methodologies inherent to the Wetlands package were suitable for simulating regional wetland hydrology within the Everglades area. 相似文献
83.
Mannino I Franco D Piccioni E Favero L Mattiuzzo E Zanetto G 《Environmental management》2008,41(1):118-129
A cost-effectiveness analysis was performed to evaluate the competitiveness of seminatural Free Water Surface (FWS) wetlands
compared to traditional wastewater-treatment plants. Six scenarios of the service costs of three FWS wetlands and three different
wastewater-treatment plants based on active sludge processes were compared. The six scenarios were all equally effective in
their wastewater-treatment capacity. The service costs were estimated using real accounting data from an experimental wetland
and by means of a market survey. Some assumptions had to be made to perform the analysis. A reference wastewater situation
was established to solve the problem of the different levels of dilution that characterize the inflow water of the different
systems; the land purchase cost was excluded from the analysis, considering the use of public land as shared social services,
and an equal life span for both seminatural and traditional wastewater-treatment plants was set. The results suggest that
seminatural systems are competitive with traditional biotechnological systems, with an average service cost improvement of
2.1-fold to 8-fold, according to the specific solution and discount rate. The main improvement factor was the lower maintenance
cost of the seminatural systems, due to the self-regulating, low artificial energy inputs and the absence of waste to be disposed.
In this work, only the waste-treatment capacity of wetlands was considered as a parameter for the economic competitiveness
analysis. Other goods/services and environmental benefits provided by FWS wetlands were not considered.
相似文献
Daniel FrancoEmail: |
84.
85.
青海湖几种主要湿地植物的种群分布格局及动态 总被引:23,自引:2,他引:23
应用种群生态空间分布的分析方法,研究了青海湖四种主要湿地植物:杉叶藻(Hippuris vulgaris)、槽杆荸荠(Eleocharis valleculosa)、华扁穗莞(Blysmus sinocompresus)、碱蓬(Suaeda glauca)的空间分布格局及其动态,研究表明:杉叶藻、槽杆荸荠、华扁穗莞三种群由侵入期、定期初期到种群发育盛期的过程中,其集群程度先增大后减小,总体呈扩散的趋势;碱蓬种群,从幼苗到繁殖期,集群程度增大,呈聚集的趋势,说明前三种植物的克隆繁殖方式于滨湖湿地生境具有更好的生态适应性,图2表3参11 相似文献
86.
87.
3种不同基质潜流湿地对磷的去除效果 总被引:12,自引:0,他引:12
基质是潜流式人工湿地污水处理系统的重要组成部分,直接影响到系统的处理效果。本文研究了由沸石、页岩陶粒和碎石3种不同基质构建的潜流式人工湿地对磷的去除效果。结果表明,在设计水力停留时间3d,连续进出水情况下,碎石单元对磷的去除效果最好,页岩陶粒单元次之,沸石单元效果最差,平均去除率分别为95%、60%和35%。在潜流式人工湿地污水处理系统运行初期观察到磷释放现象,沸石单元最为明显。进水磷浓度较低时,磷的去除率随浓度升高而升高,当正磷、总磷浓度分别升高到2.4—2.5和3.1~3.3mg/L时,正磷、总磷的去除率开始迅速下降。 相似文献
88.
建立潜流湿地有机污染物迁移转化模型,采用多孔介质模型描述潜流湿地的水力特性,并引入Monod方程相耦合,实现对湿地系统内部流场及水质浓度的同时模拟。通过实验,校核模型参数,并验证模型。结果表明,该模型能较好模拟潜流湿地中有机污染物的去除效果;计算条件下,在不同基质填料的潜流湿地中都会出现滞水区和快速通道,影响水力效率与污染物去除效果;预测了不同填料系统中7种典型选控性有机污染物的去除效果,其处理效率:苯胺苯酚二甲苯甲苯苯硝基苯氯苯,可通过优选填料提高吸附量和延长停留时间来提高选控性有机物的处理效果。 相似文献
89.
对人工湿地污水处理工艺及其对水中污染物的去除机理进行了综述,并对人工湿地处理污水的技术进行了展望。 相似文献
90.
人工湿地在污水处理中的应用及其展望 总被引:9,自引:0,他引:9
作为污水处理的有效途径,人工湿地具有众多的优点。本文分析了人工湿地的构造及去污机理,总结了人工湿地在污水处理中应用的历史及现状,并对其未来的应用前景做出了展望。 相似文献