全文获取类型
收费全文 | 916篇 |
免费 | 18篇 |
国内免费 | 17篇 |
专业分类
安全科学 | 89篇 |
废物处理 | 29篇 |
环保管理 | 186篇 |
综合类 | 397篇 |
基础理论 | 87篇 |
污染及防治 | 52篇 |
评价与监测 | 74篇 |
社会与环境 | 16篇 |
灾害及防治 | 21篇 |
出版年
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 4篇 |
2020年 | 10篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2017年 | 18篇 |
2016年 | 28篇 |
2015年 | 30篇 |
2014年 | 63篇 |
2013年 | 53篇 |
2012年 | 31篇 |
2011年 | 79篇 |
2010年 | 45篇 |
2009年 | 63篇 |
2008年 | 60篇 |
2007年 | 32篇 |
2006年 | 45篇 |
2005年 | 41篇 |
2004年 | 42篇 |
2003年 | 28篇 |
2002年 | 33篇 |
2001年 | 15篇 |
2000年 | 30篇 |
1999年 | 31篇 |
1998年 | 25篇 |
1997年 | 24篇 |
1996年 | 21篇 |
1995年 | 16篇 |
1994年 | 18篇 |
1993年 | 17篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有951条查询结果,搜索用时 46 毫秒
481.
易燃易爆氢氧车间生产、贮气柜系统危险性评价 总被引:2,自引:0,他引:2
通过某动力公司氢氧车间生产、贮存系统危险性因素分析 ,对氢氧车间氢气生产、贮存各工艺环节进行了火灾爆炸危险性评价 ,并针对氢氧车间生产工艺系统和湿式贮气柜的火灾爆炸事故隐患 ,提出了事故防范的安全对策。 相似文献
482.
安全评价中危险辨识的地位、存在问题和对策 总被引:8,自引:7,他引:8
生产企业、系统、工程或设备的安全性程度 ,需按有关规定或技术要求 ,进行各种形式的安全评价。安全评价是危险评价 ,其中辨识危险在安全评价中具有重要意义。笔者论述了危险辨识在安全评价中的地位 ;指出了危险辨识存在的问题 ;从资料准备、企业调研、危险辨识方法、行业专家作用和人员素质等 7个方面提出了解决现存问题的对策及措施。安全评价是落实“安全第一 ,预防为主”方针 ,消除隐患 ,预防和预测事故 ,确保安全生产的重要手段 相似文献
483.
Ecological limitations and appropriation of ecosystem support by shrimp farming in Colombia 总被引:4,自引:0,他引:4
Shrimp farming in mangrove areas has grown dramatically in Asia and Latin America over the past decade. As a result, demand
for resources required for farming, such as feed, seed, and clean water, has increased substantially. This study focuses on
semiintensive shrimp culture as practiced on the Caribbean coast of Colombia. We estimated the spatial ecosystem support that
is required to produce the food inputs, nursery areas, and clean water to the shrimp farms, as well as to process wastes.
We also made an estimate of the natural and human-made resources necessary to run a typical semiintensive shrimp farm. The
results show that a semiintensive shrimp farm needs a spatial ecosystem support—the ecological footprint—that is 35–190 times
larger than the surface area of the farm. A typical such shrimp farm appropriates about 295 J of ecological work for each
joule of edible shrimp protein produced. The corresponding figure for industrial energy is 40:1. More than 80% of the ecological
primary production required to feed the shrimps is derived from external ecosystems. In 1990 an area of 874–2300 km2 of mangrove was required to supply shrimp postlarvae to the farms in Colombia, corresponding to a total area equivalent to
about 20–50% of the country’s total mangrove area. The results were compared with similar estimates for other food production
systems, particularly aquacultural ones. The comparison indicates that shrimp farming ranks as one of the most resource-intensive
food production systems, characterizing it as an ecologically unsustainable throughput system. Based on the results, we discuss
local, national, and regional appropriation of ecological support by the semiintensive shrimp farms. Suggestions are made
for how shrimp farming could be transformed into a food production system that is less environmentally degrading and less
dependent on external support areas. 相似文献
484.
风暴潮期间海塘工程的安全是防汛工作的重要问题。本文对海塘工程安全的影响因素进行了分析,提出了海塘工程安全预警的思路,并将决策支持系统这一新技术引入防台抗潮的决策工作中,以提高决策人的决策能力。 相似文献
485.
Ecological risk assessment provides a methodology for evaluating the threats to ecosystem function associated with environmental
perturbations or stressors. This report documents the development of a conceptual model for assessing the ecological risk
to the water quality function (WQF) of bottomland hardwood riparian ecosystems (BHRE) in the Tifton-Vidalia upland (TVU) ecoregion
of Georgia. Previus research has demonstrated that mature BHRE are essential to maintaining water quality in this portion
of the coastal plain. The WQF of these ecosystems is considered an assessment endpoit—an ecosystem function or set of functions
that society chooses to value as evidenced by laws, regulations, or common usage. Stressors operate on ecosystems at risk
through an exposure scenario to produce ecological effects that are linked to loss of the desired function or assessment end
point. The WQF of BHRE is at risk because of the ecological and environmental quality effects of a suite of chemical, physical,
and biological stressors. The stressors are related to nonpoint source pollution from adjacent land uses, especially agriculture;
the conversion of BHRE to other land uses; and the encroachment of domestic animals into BHRE. Potential chemical, physical,
and biological stressors to BHRE are identified, and the methodology for evaluating appropriate exposure scenarios is discussed.
Field-scale and watershed-scale measurement end points of most use in assessing the effects of stressors on the WQF are identified
and discussed. The product of this study is a conceptual model of how risks to the WQF of BHRE are produced and how the risk
and associated uncertainties can be quantified. 相似文献
486.
Maohua Zhong Tiemin Liu Yunfeng Deng Congling Shi Tairan Fu Xueyi Hu 《Journal of Loss Prevention in the Process Industries》2006,19(6):762-768
This paper mainly reviews on safety evaluation in China in recent years, explains the role of safety evaluation playing in work safety and introduces the progress of safety evaluation made in industries. Also it introduces some important provisions on Safety Evaluation Agencies (SEA), and the evaluation specifications and standards, on which the safety evaluation is carried out, issued by China government. Furthermore, it analyzes the incompletes in safety evaluation and discusses their possible influence on SEA, local administration of work safety and the public's reorganization, and indicates the key points to be developed in China future safety evaluation. 相似文献
487.
由于污染排放存在时空与行业"热点"(hot spots)问题,针对非均匀污染物建立跨区域排污权交易体系具有一定困难。基于一种新的污染外部性度量系数,本文对传统的达标检测方法进行了改进,在此改进达标检测法上构建的跨区域排污权交易体系,能够在简化交易机制和管理工作的同时较好地解决"热点"问题,在社会总产出和总排污量不变的情况下实现社会福利的帕累托改进。 相似文献
488.
辉河湿地国家自然保护区生态系统健康评价 总被引:5,自引:2,他引:3
在RS和GIS技术的支持下,以1975和2006年两期遥感影像为信息源,从生态系统空间范围和服务功能价值变化的角度对呼伦贝尔辉河草原湿地国家级自然保护区的生态系统健康状况进行了分析.结果表明,1975~2006年间辉河湿地自然保护区的草原和湖泊面积分别减少了7346和2731hm2,湿地和干涸湖面积分别增加了6877和2953 hm2.从自然保护区的核心——湿地生态系统的斑块格局变化来看,1975~2006年间斑块密度增加了74.48个.hm-2,斑块连通度在100~300m的阈限值范围内呈减少的趋势,平均减少0.069±0.038.基于生态系统服务价值的评价结果表明,1975~2006年间辉河湿地国家自然保护区生态系统达到健康水平以上的区域面积为323215 hm2,占保护区面积的93.31%,生态系统较差和恶劣区的面积为23177 hm2,占总面积的6.69%.研究区的总生态价值盈余为8.8×107元,其盈余主要来源于草原向湿地的转化、水体向湿地的转化及干涸湖向草原的转化. 相似文献
489.
490.