全文获取类型
收费全文 | 993篇 |
免费 | 78篇 |
国内免费 | 194篇 |
专业分类
安全科学 | 102篇 |
废物处理 | 7篇 |
环保管理 | 408篇 |
综合类 | 478篇 |
基础理论 | 104篇 |
污染及防治 | 57篇 |
评价与监测 | 46篇 |
社会与环境 | 36篇 |
灾害及防治 | 27篇 |
出版年
2023年 | 16篇 |
2022年 | 15篇 |
2021年 | 25篇 |
2020年 | 37篇 |
2019年 | 34篇 |
2018年 | 31篇 |
2017年 | 32篇 |
2016年 | 37篇 |
2015年 | 51篇 |
2014年 | 42篇 |
2013年 | 56篇 |
2012年 | 71篇 |
2011年 | 49篇 |
2010年 | 48篇 |
2009年 | 41篇 |
2008年 | 46篇 |
2007年 | 45篇 |
2006年 | 61篇 |
2005年 | 53篇 |
2004年 | 38篇 |
2003年 | 40篇 |
2002年 | 35篇 |
2001年 | 31篇 |
2000年 | 32篇 |
1999年 | 20篇 |
1998年 | 24篇 |
1997年 | 19篇 |
1996年 | 12篇 |
1995年 | 13篇 |
1994年 | 13篇 |
1993年 | 15篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 12篇 |
1987年 | 15篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1981年 | 11篇 |
1980年 | 13篇 |
1979年 | 15篇 |
1978年 | 13篇 |
1977年 | 9篇 |
1975年 | 8篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1970年 | 4篇 |
排序方式: 共有1265条查询结果,搜索用时 78 毫秒
51.
莆田市城市排水行业的现状与发展建议 总被引:1,自引:1,他引:0
论述了莆田市排水行业的现状、近年来取得的进展和目前存在的一些主要问题。针对这些问题.笔者结合莆田市的实际情况对今后的发展提出了具体的建议和对策。 相似文献
52.
排水管网设计中管材的选择 总被引:1,自引:0,他引:1
排水管网使用的各类排水管材种类繁多,性能差异较大.根据排水管材的材质、性能分析,对常用几种排水管材进行了技术经济比较.以实际工程为例,概述了不同施工条件和不同地质条件下排水管材的设计选择方法. 相似文献
53.
为研究高瓦斯易自燃煤层不同供风量、高抽巷抽采流量、低抽巷抽采流量3因素对采空区自燃“三带”分布影响规律,选取阳煤五矿8406工作面为研究对象,在数值模拟研究基础上,采用Design Expert软件进行Box Behnken试验设计,构建采空区氧化升温带宽度在3因素、3水平条件下的二次回归响应曲面模型,并对不同条件下采空区氧化升温带宽度进行预测与分析。结果表明:二次回归方程P值为0.001 6,预测模型显著,模型的失拟项为0.606 3,不显著,回归方程具有统计学意义;当供风量为1 500~2 000 m3/min,低抽流量为450~650 m3/min,高抽流量为100~200 m3/min时,对氧化升温带宽度一次项重要度排序为C(高抽巷抽采流量)>A(供风量)>B(低抽巷抽采流量),二次项重要度排序为AC(供风量和高抽巷抽采流量)>AB(供风量和低抽巷抽采流量)>BC(低抽巷抽采流量和高抽巷抽采流量),且AB,AC,BC之间均无交互作用。 相似文献
54.
Nicole F. Opalinski Aditi S. Bhaskar Dale T. Manning 《Journal of the American Water Resources Association》2020,56(1):68-81
Weather variability has the potential to influence municipal water use, particularly in dry regions such as the western United States (U.S.). Outdoor water use can account for more than half of annual household water use and may be particularly responsive to weather, but little is known about how the expected magnitude of these responses varies across the U.S. This nationwide study identified the response of municipal water use to monthly weather (i.e., temperature, precipitation, evapotranspiration [ET]) using monthly water deliveries for 229 cities in the contiguous U.S. Using city‐specific multiple regression and region‐specific models with city fixed effects, we investigated what portion of the variability in municipal water use was explained by weather across cities, and also estimated responses to weather across seasons and climate regions. Our findings indicated municipal water use was generally well‐explained by weather, with median adjusted R2 ranging from 63% to 95% across climate regions. Weather was more predictive of water use in dry climates compared to wet, and temperature had more explanatory power than precipitation or ET. In response to a 1°C increase in monthly maximum temperature, municipal water use was shown to increase by 3.2% and 3.9% in dry cities in winter and summer, respectively, with smaller changes in wet cities. Quantifying these responses allows urban water managers to plan for weather‐driven variability in water use. 相似文献
55.
Andrew S. Jones Allan A. Andales Jos L. Chvez Cullen McGovern Garvey E.B. Smith Olaf David Steven J. Fletcher 《Journal of the American Water Resources Association》2020,56(2):201-211
We apply predictive weather metrics and land model sensitivities to improve the Colorado State University Water Irrigation Scheduler for Efficient Application (WISE). WISE is an irrigation decision aid that integrates environmental and user information for optimizing water use. Rainfall forecasts and verification performance metrics are used to estimate predictive rainfall probabilities that are used as input data within the irrigation decision aid. These input data errors are also used within a land model sensitivity study to diagnose important prognostic water movement behaviors for irrigation tool development purposes simultaneously performing the analysis in space and time. Thus, important questions such as “how long can a crop water application be delayed while maintaining crop yield production?” are addressed by evaluating crop growth stage interactions as a function of soil depth (i.e., space), rainfall events (i.e., time), and their probabilistic uncertainties. Editor’s note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series. 相似文献
56.
Carroll S Goonetilleke A Thomas E Hargreaves M Frost R Dawes L 《Environmental management》2006,38(2):286-303
Onsite wastewater treatment systems (OWTS) are becoming increasingly important for the treatment and dispersal of effluent
in new urbanised developments that are not serviced by centralised wastewater collection and treatment systems. However, the
current standards and guidelines adopted by many local authorities for assessing suitable site and soil conditions for OWTS
are increasingly coming under scrutiny due to the public health and environmental impacts caused by poorly performing systems,
in particular septic tank-soil adsorption systems. In order to achieve sustainable onsite wastewater treatment with minimal
impacts on the environment and public health, more appropriate means of assessment are required. This paper highlights an
integrated risk based approach for assessing the inherent hazards associated with OWTS in order to manage and mitigate the
environmental and public health risks inherent with onsite wastewater treatment. In developing a sound and cohesive integrated
risk framework for OWTS, several key issues must be recognised. These include the inclusion of relevant stakeholders throughout
framework development, the integration of scientific knowledge, data and analysis with risk assessment and management ideals,
and identification of the appropriate performance goals for successful management and mitigation of associated risks. These
issues were addressed in the development of the risk framework to provide a generic approach to assessing risk from OWTS.
The utilisation of the developed risk framework for achieving more appropriate assessment and management techniques for OWTS
is presented in a case study for the Gold Coast region, Queensland State, Australia. 相似文献
57.
58.
随着遥感数据源的不断丰富,遥感技术不断提高,可以解决越来越多的水环境问题。指出了当前水生态环境管理方面的主要需求,结合目前遥感技术的发展,对国内外的水环境遥感研究进展进行综述。以湖泊富营养化监测与评估、核电站温排水遥感监测及城市黑臭水体遥感监测为案例,具体阐述遥感在水环境管理中的应用方法及成效。未来水生态环境管理发展趋势将以水污染防治为主向水污染防治和水生态修复与保护并重发展。基于此趋势,提出遥感在水生态修复的应用潜力,利于更多地方部门积极有效应用遥感技术,解决水生态环境问题。 相似文献
59.
pH对沟渠沉积物截留农田排水沟渠中氮、磷的影响研究 总被引:11,自引:0,他引:11
通过摇瓶动态实验和箱体静止实验,研究了不同pH条件下沟渠沉积物对农田流失氮、磷的截留效应,分析了pH对氮、磷截留效应及其界面交换作用的影响.结果表明:在实验pH变化范围内,沟渠沉积物对NH 4-N的吸附量和NO-2-N的硝化量以及对TN的截留率都是随着pH的增加而增加;沟渠沉积物对总溶解性磷(TDP)的吸附量随着pH的增加而增加,TP的截留率在5 d前随pH的增加而增加,但在此后基本不发生变化;在不同的pH下,通过影响微生物的活动直接或间接影响氮的界面交换行为,同时pH通过影响沉积物的吸附作用和离子交换作用来影响磷在沉积物-水界面的交换行为.阐明pH对沟渠沉积物氮、磷截留效应的影响有助于掌握氮、磷在农田排水沟渠中的迁移转化机理,从而对控制农业面源污染具有重要的意义. 相似文献
60.