全文获取类型
收费全文 | 1054篇 |
免费 | 46篇 |
国内免费 | 50篇 |
专业分类
安全科学 | 116篇 |
废物处理 | 7篇 |
环保管理 | 207篇 |
综合类 | 493篇 |
基础理论 | 114篇 |
污染及防治 | 41篇 |
评价与监测 | 84篇 |
社会与环境 | 56篇 |
灾害及防治 | 32篇 |
出版年
2023年 | 7篇 |
2022年 | 11篇 |
2021年 | 17篇 |
2020年 | 38篇 |
2019年 | 20篇 |
2018年 | 11篇 |
2017年 | 24篇 |
2016年 | 41篇 |
2015年 | 42篇 |
2014年 | 49篇 |
2013年 | 83篇 |
2012年 | 42篇 |
2011年 | 73篇 |
2010年 | 32篇 |
2009年 | 55篇 |
2008年 | 44篇 |
2007年 | 64篇 |
2006年 | 48篇 |
2005年 | 48篇 |
2004年 | 40篇 |
2003年 | 47篇 |
2002年 | 35篇 |
2001年 | 34篇 |
2000年 | 43篇 |
1999年 | 35篇 |
1998年 | 32篇 |
1997年 | 23篇 |
1996年 | 17篇 |
1995年 | 22篇 |
1994年 | 16篇 |
1993年 | 11篇 |
1992年 | 13篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1972年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有1150条查询结果,搜索用时 250 毫秒
1.
氢氟酸的污染与防治 总被引:1,自引:0,他引:1
方慧萍 《石油化工环境保护》1997,(1):52-54
综述氢氟酸烷基化装置,运行过程中氢氟酸的危害,污染源的分析,防治措施及取得效果. 相似文献
2.
Ozone (O3), as a harmful air pollutant, has been of wide concern. Safe, efficient, and economical O3 removal methods urgently need to be developed. Catalytic decomposition is the most promising method for O3 removal, especially at room temperature or even subzero temperatures. Great efforts have been made to develop high-efficiency catalysts for O3 decomposition that can operate at low temperatures, high space velocity and high humidity. First, this review describes the general reaction mechanism of O3 decomposition on noble metal and transition metal oxide catalysts. Then, progress on the O3 decomposition performance of various catalysts in the past 30 years is summarized in detail. The main focus is the O3 decomposition performance of manganese oxides, which are divided into supported manganese oxides and non-supported manganese oxides. Methods to improve the activity, stability, and humidity resistance of manganese oxide catalysts for O3 decomposition are also summarized. The deactivation mechanisms of manganese oxides under dry and humid conditions are discussed. The O3 decomposition performance of monolithic catalysts is also summarized from the perspective of industrial applications. Finally, the future development directions and prospects of O3 catalytic decomposition technology are put forward. 相似文献
3.
Bertram P Stadler-Salt N Horvatin P Shear H;State of the Lakes Ecosystem Conferences 《Environmental monitoring and assessment》2003,81(1-3):27-33
Many administrative jurisdictions have authority over parts of the Great Lakes, sometimes with competing purposes as well as governance at differing scales of time and space. As demand increases for high quality information that is relevant to environmental managers, environmental and natural resource agencies with limited budgets must look to interdisciplinary, collaborative approaches for the collection, analysis and reporting of data. The State of the Lakes Ecosystem Conferences (SOLEC) were begun in 1994 in response to reporting requirements of the Great Lakes Water Quality Agreement between Canada and the U.S. The biennial conferences provide independent, science-based reporting on the state of health of the Great Lakes ecosystem components. A suite of indicators necessary and sufficient to assess Great Lakes ecosystem status was introduced in 1998, and assessments based on a subset of the indicators were presented in 2000. Because SOLEC is a multi-agency, multi-jurisdictional reporting venue, the SOLEC indicators require acceptance by a broad spectrum of stakeholders in the Great Lakes basin. The SOLEC indicators list is expected to provide the basis for government agencies and other organizations to collaborate more effectively and to allocate resources to data collection, evaluation and reporting on the state of the Great Lakes basin ecosystem. 相似文献
4.
This paper presents development of a first approximation of a Namibian, national level, land degradation monitoring system.
The process involved a large number of stakeholders and led to the definition of four primary indicators that were regarded
as related to land degradation in Namibia: population pressure, livestock pressure, seasonal rainfall and erosion hazards.
These indicators were calculated annually for the period 1971–1997. Annual land degradation risk maps were produced for the
same period by combining the indicators. A time series analysis of results generated by indicators was undertaken at two sites.
The analysis revealed a general trend towards an increased land degradation risk over the period 1971–1997. A decrease in
annual rainfall and an increase in livestock numbers caused this negative trend at one site, while decreased annual rainfall
and increased human population were the causes at a second site. Evaluation of resulting maps through direct field observations
and long-term monitoring at selected study sites with different conditions relevant for the indicators defined, is an essential
next step. 相似文献
5.
Llansó RJ Dauer DM Vølstad JH Scott LC 《Environmental monitoring and assessment》2003,81(1-3):163-174
The Chesapeake Bay benthic index of biotic integrity (B-IBI) was developed to assess benthic community health and environmental quality in Chesapeake Bay. The B-IBI provides Chesapeake Bay monitoring programs with a uniform tool with which to characterize bay-wide benthic community condition and assess the health of the Bay. A probability-based design permits unbiased annual estimates of areal degradation within the Chesapeake Bay and its tributaries with quantifiable precision. However, of greatest interest to managers is the identification of problem areas most in need of restoration. Here we apply the B-IBI to benthic data collected in the Bay since 1994 to assess benthic community degradation by Chesapeake Bay Program segment and water depth. We used a new B-IBI classification system that improves the reliability of the estimates of degradation. Estimates were produced for 67 Chesapeake Bay Program segments. Greatest degradation was found in areas that are known to experience hypoxia or show toxic contamination, such as the mesohaline portion of the Potomac River, the Patapsco River, and the Maryland mainstem. Logistic regression models revealed increased probability of degraded benthos with depth for the lower Potomac River, Patapsco River, Nanticoke River, lower York River, and the Maryland mainstem. Our assessment of degradation by segment and water depth provided greater resolution of relative condition than previously available, and helped define the extent of degradation in Chesapeake Bay. 相似文献
6.
Marco Ferretti 《Environmental monitoring and assessment》1997,48(1):45-72
Part of this paper has been prepared for the lecture Forest Health Assessment-Criteria,Methods and Problems given by the author at the UIMPuniversity course Sanidad Forestal en el Bosques Mediterraneos yTemplados. Implicacion de la Contaminacion Atmosferica y del Cambio Global, held in Valencia, Spain, October, 1995. Assessment and monitoring of forest health representsa key point for environmental policy and for the management ofenvironmental resources. With the renewed interest in assessment andmonitoring of forest health generated by the suspected occurrence ofa widespread forest decline in Europe and North America, manyactivities have been undertaken: however, some questions should beconsidered and clarified when attempting to estimate forest health.Particularly, the objective(s) of the assessment and monitoringprogram should be carefully identified. Identification of a program‘stask has a number of implications and consequences: it implies adefinition of what concept of forest health (forest ecosystem health,forest health or forest trees health?) is assumed, what will be thetarget entity to be monitored, and therefore the identification of therelevant assessment questions and assessment endpoints.Consequences concern the definition of the spatial scale (frominternational to landscape and plot scale monitoring) and ecologicalcoverage (from single species population to population ofecosystems) of the program, which can have a considerable influenceon the choice of the proper sampling strategy and tactic, as well ason the most suitable methods, indicators and indices to be used.Although much of the work in the field of forest health and airpollution has concentrated on surveys on crown transparency anddiscoloration, there is an entire range of methods, indicators andindices developed to assess the health status of forests. The decisionas to which ones should be used will depend on the aim of theprogram and on economic and practical considerations. A furtherconsideration concerns the time span of the program, but anydecision in this field is subject to many limitations due to difficultiesin predicting future monitoring needs. All these points should becarefully considered and implemented according to a rigorousQuality Assurance procedure since any decision will influence futurework for many years. 相似文献
7.
北京市地表水环境面临的主要问题及防治对策 总被引:6,自引:2,他引:6
针对北京市地表水水质污染现状、污染特点及其变化趋势,深入剖析了目前地表水环境及其治理过程中存在的主要问题,提出进一步改善北京市地表水环境的措施与建议。 相似文献
8.
以石油类储存为例,通过其在固定顶罐储存、装卸的呼吸排放和工作排放的计算分析,提出控制有机液体排放的工程技术措施和管理措施。 相似文献
9.
This paper presents a new tool for promoting business sustainability — indicators of sustainable production. It first introduces the concept of sustainable production as defined by the Lowell Center for Sustainable Production, University of Massachusetts Lowell. Indicators of sustainable production are discussed next, including their dimensions and desirable qualities. Based on the Lowell Center Indicator Framework, the authors suggest a new methodology of core and supplemental indicators for raising companies' awareness and measuring their progress toward sustainable production systems. Twenty-two core indicators are proposed and a detailed guidance for their application is included. An eight-step model provides a context for indicator implementation. The paper concludes with a summary of the strengths and weaknesses of the methodology as well as recommendations for testing the indicators. 相似文献
10.