全文获取类型
收费全文 | 749篇 |
免费 | 33篇 |
国内免费 | 26篇 |
专业分类
安全科学 | 204篇 |
废物处理 | 10篇 |
环保管理 | 102篇 |
综合类 | 290篇 |
基础理论 | 49篇 |
污染及防治 | 24篇 |
评价与监测 | 54篇 |
社会与环境 | 20篇 |
灾害及防治 | 55篇 |
出版年
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 18篇 |
2020年 | 11篇 |
2019年 | 9篇 |
2018年 | 9篇 |
2017年 | 21篇 |
2016年 | 22篇 |
2015年 | 19篇 |
2014年 | 36篇 |
2013年 | 29篇 |
2012年 | 36篇 |
2011年 | 51篇 |
2010年 | 35篇 |
2009年 | 41篇 |
2008年 | 33篇 |
2007年 | 33篇 |
2006年 | 39篇 |
2005年 | 43篇 |
2004年 | 49篇 |
2003年 | 39篇 |
2002年 | 31篇 |
2001年 | 18篇 |
2000年 | 22篇 |
1999年 | 21篇 |
1998年 | 19篇 |
1997年 | 12篇 |
1996年 | 18篇 |
1995年 | 26篇 |
1994年 | 12篇 |
1993年 | 14篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有808条查询结果,搜索用时 515 毫秒
431.
研究了城市地铁产生的二次辐射噪声测量现状及评价方法,依据现行地铁二次辐射噪声监测相关标准,对城市地铁产生的二次辐射噪声进行测量,将JGJ/T 170—2009、GB 50118—2010和GB/T 50355—2018中规定的限值与地铁二次辐射噪声的特征频谱、环境影响评价以及噪声限值进行了对比分析。结果显示,现行标准限值在执行中存在一定的不完善之处,需要根据实测数据重新分析评价标准的适用性、准确性和合理性。结合当前噪声管理的社会需求,提出了声级增量和特征频谱增量的概念,并将分析结果与现行标准值进行了比较分析,表明声级增量和特征频谱增量能更好地反映二次辐射噪声的影响,对于地铁二次辐射噪声标准的制修订具有参考价值。 相似文献
432.
433.
Groundwater Vulnerability Assessment for Organic Compounds: Fuzzy Multicriteria Approach for Mexico City 总被引:1,自引:0,他引:1
Mazari-Hiriart M Cruz-Bello G Bojórquez-Tapia LA Juárez-Marusich L Alcantar-López G Marín LE Soto-Galera E 《Environmental management》2006,37(3):410-421
This study was based on a groundwater vulnerability assessment approach implemented for the Mexico City Metropolitan Area
(MCMA). The approach is based on a fuzzy multicriteria procedure integrated in a geographic information system. The approach
combined the potential contaminant sources with the permeability of geological materials. Initially, contaminant sources were
ranked by experts through the Analytic Hierarchy Process. An aggregated contaminant sources map layer was obtained through
the simple additive weighting method, using a scalar multiplication of criteria weights and binary maps showing the location
of each source. A permeability map layer was obtained through the reclassification of a geology map using the respective hydraulic
conductivity values, followed by a linear normalization of these values against a compatible scale. A fuzzy logic procedure
was then applied to transform and combine the two map layers, resulting in a groundwater vulnerability map layer of five classes:
very low, low, moderate, high, and very high. Results provided a more coherent assessment of the policy-making priorities
considered when discussing the vulnerability of groundwater to organic compounds. The very high and high vulnerability areas
covered a relatively small area (71 km2 or 1.5% of the total study area), allowing the identification of the more critical locations. The advantage of a fuzzy logic
procedure is that it enables the best possible use to be made of the information available regarding groundwater vulnerability
in the MCMA. 相似文献
434.
A System Dynamics Model for the Environmental Management of the Sepetiba Bay Watershed, Brazil 总被引:2,自引:0,他引:2
In the recent past, the Sepetiba Bay watershed, located in the Rio de Janeiro State, Brazil has experienced rapid industrial
development and population growth, as well as an increase in water pollution and environmental degradation. To analyze the
complex interrelationships among the agents affecting the Sepetibza Bay environment, a system dynamics model was developed.
The model builds on extensive studies conducted for the watershed, and simulates different hypotheses of economic growth and
of demographic expansion. Thus, it can be used as a decision support tool for the identification of investment priorities
and policy analyses under various scenarios. In order to provide a comprehensive approach to the environmental management
of the Sepetiba Bay watershed, the model had to consider only the most relevant aspects of the behavior and the key interactions
among agents operating in the watershed. In this article, the model’s structure is presented together with some of its main
results. 相似文献
435.
环境决策支持系统的设计技术及发展趋势 总被引:4,自引:2,他引:2
简要论述了环境决策支持系统(EDSS)的发展历程,提出了EDSS开发技术的六大构成部分:应用平台的选择;系统的开发方式的选择;系统的开发工具的选择;系统的组成结构的建立;系统的基本功能的设计;系统的开放接口的设计。对系统设计的关键技术进行了分析,依据EDSS的应用现状,指出EDSS的发展趋势,对实际应用具有一定的指导意义和实用价值。 相似文献
436.
Towards a Formal Framework of Vulnerability to Climate Change 总被引:7,自引:0,他引:7
Cezar Ionescu Richard J. T. Klein Jochen Hinkel K. S. Kavi Kumar Rupert Klein 《Environmental Modeling and Assessment》2009,14(1):1-16
There is confusion regarding the notion of “vulnerability” in the climate change scientific community. Recent research has
identified a need for formalisation, which would support accurate communication and the elimination of misunderstandings that
result from the use of ambiguous terminology. Moreover, a formal framework of vulnerability is a prerequisite for computational
approaches to its assessment. This paper presents an attempt at developing such a formal framework. We see vulnerability as
a relative concept in the sense that accurate statements about vulnerability are possible only if one clearly specifies (1)
the entity that is vulnerable, (2) the stimulus to which it is vulnerable and (3) the preference criteria to evaluate the
outcome of the interaction between the entity and the stimulus. We relate the resulting framework to the Intergovernmental
Panel on Climate Change conceptualisation of vulnerability and two recent vulnerability studies.
This paper is dedicated to the memory of Gerhard Petschel-Held, whose pioneering work on syndromes of global change has been
a source of inspiration for us and for others across various schools of thought on vulnerability. 相似文献
437.
简述了水污染源在线监测设备系统集成的必要性,分析了目前系统集成中存在的问题,以及应采取的对策。按照国家有关规范要求,对现场端的在线监测设备进行科学的综合布局,并从采水、配水、预处理、控制、分析、数据采集与传输、辅助等构成单元,提出了有关水污染源在线监测设备系统集成的方案。 相似文献
438.
低浓度SO2和NOx 自动监测系统性能评价方法 总被引:1,自引:0,他引:1
通过对7种废气自动监测系统的比较研究和现场测试,提出了非分散红外法、紫外差分法、紫外荧光法、化学发光法等多种 SO2和 NO x 自动监测技术在低浓度范围实现准确定量监测的性能评价方法,定义了 CEMS 的系统检出限及其主要影响因素。建议采用系统检出限、线性误差等关键参数作为低浓度 CEMS 的性能评价方法,提出将全系统多点标准气体校准或加标回收率作为验收和质控监督的基本方法。 相似文献
439.
440.
简述了目前比对监测工作的依据以及比对监测现状,指出了比对工作的常见问题,如共性问题、颗粒物比对监测、二氧化硫比对监测、流速比对监测、合理选择比对方法等,提出了相应的解决办法,监测人员应对各种参比监测方法熟练掌握,了解各个企业的CEMS系统原理、方法和工况,在保证监测数据准确性的前提下提高比对工作的一致性。 相似文献