全文获取类型
收费全文 | 833篇 |
免费 | 28篇 |
国内免费 | 81篇 |
专业分类
安全科学 | 45篇 |
废物处理 | 6篇 |
环保管理 | 116篇 |
综合类 | 330篇 |
基础理论 | 55篇 |
污染及防治 | 160篇 |
评价与监测 | 137篇 |
社会与环境 | 58篇 |
灾害及防治 | 35篇 |
出版年
2024年 | 1篇 |
2023年 | 24篇 |
2022年 | 13篇 |
2021年 | 16篇 |
2020年 | 22篇 |
2019年 | 16篇 |
2018年 | 22篇 |
2017年 | 11篇 |
2016年 | 15篇 |
2015年 | 15篇 |
2014年 | 36篇 |
2013年 | 35篇 |
2012年 | 28篇 |
2011年 | 66篇 |
2010年 | 35篇 |
2009年 | 60篇 |
2008年 | 57篇 |
2007年 | 51篇 |
2006年 | 35篇 |
2005年 | 21篇 |
2004年 | 24篇 |
2003年 | 19篇 |
2002年 | 27篇 |
2001年 | 24篇 |
2000年 | 29篇 |
1999年 | 27篇 |
1998年 | 35篇 |
1997年 | 32篇 |
1996年 | 11篇 |
1995年 | 27篇 |
1994年 | 22篇 |
1993年 | 13篇 |
1992年 | 25篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 11篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有942条查询结果,搜索用时 718 毫秒
851.
Correlating element atmospheric deposition and cancer mortality in Portugal: data handling and preliminary results 总被引:1,自引:0,他引:1
Sarmento S Wolterbeek HT Verburg TG Freitas MC 《Environmental pollution (Barking, Essex : 1987)》2008,151(2):341-351
This study, framed within geographical epidemiology, presents preliminary findings concerning the association between the concentrations of chemical elements obtained through atmospheric biomonitoring with lichens and cancer mortality in the Portuguese population. Exploratory analyses were performed to identify potential confounders for the relationships between chemical elements and neoplasm mortality and to assess the extent of their interference. The results of this study highlight some methodological and conceptual difficulties inherent to observational and geographical studies, in the specific context of the Portuguese population, and the challenge posed by the large numbers of pollutants considered. 相似文献
852.
利用ADMS-城市模型模拟分析鞍山市大气环境质量 总被引:2,自引:0,他引:2
利用鞍山市 2 0 0 2年的TSP(总悬浮颗粒物 )和SO2 (二氧化硫 )大气环境监测资料、污染源排放清单资料和气象资料 ,以及ADMS -城市大气扩散模型进行了鞍山市大气环境质量分析。结果表明 :鞍山市低架源对地面浓度的贡献较大 ,高架源对地面浓度的贡献相对较小。 相似文献
853.
854.
The input of acidity to Swedish forest soils through forestry between 1955 and 2010 is compared with the acid input from atmospheric deposition. Depending on region, input of acidity from forestry was the minor part (25–45%) of the study period’s accumulated acid input but is now the dominating source (140–270 molc ha−1 year−1). The net uptake of cations due to the increase in standing forest biomass, ranged between 35 and 45% of the forestry related input of acidity while whole-tree harvesting, introduced in the late 1990s, contributed only marginally (< 2%). The geographical gradient in acid input is reflected in the proportion of acidified soils in Sweden but edaphic properties contribute to variations in acidification sensitivity. It is important to consider the acid input due to increases in standing forest biomass in acidification assessments since it is long-term and quantitatively important.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01540-y. 相似文献
855.
Control Strategy Optimization for Attainment and Exposure Mitigation: Case Study for Ozone in Macon, Georgia 总被引:1,自引:0,他引:1
Implementation of more stringent 8-hour ozone standards has led the U.S. Environmental Protection Agency to designate nonattainment
status to 474 counties nationwide, many of which had never previously violated air quality standards. As states select emission
control measures to achieve attainment in these regions, their choices pose significant implications to local economies and
the health of their citizens. Considering a case study of one such nonattainment region, Macon, Georgia, we develop a menu
of potential controls that could be implemented locally or in neighboring parts of the state. The control menu offers the
potential to control about 20–35% of ozone precursor emissions in most Georgia regions, but marginal costs increase rapidly
beyond 15–20%. We link high-order ozone sensitivities with the control menu to identify cost-optimized strategies for achieving
attainment and for alternative goals such as reducing spatially averaged or population-weighted ozone concentrations. Strategies
targeted toward attainment of Macon ozone would prioritize local reductions of nitrogen oxides, whereas controls in the more
densely populated Atlanta region are shown to be more effective for reducing statewide potential population exposure to ozone.
A U.S. EPA-sanctioned approach for demonstrating ozone attainment with photochemical models is shown to be highly dependent
on the choice of a baseline period and may not foster optimal strategies for assuring attainment and protecting human health. 相似文献
856.
生态文明正作为新兴文明代替工业文明,人类社会也将从工业化发展模式转向生态化发展模式。生态城市是人类物质文明与精神文明相融合的现代文明城市。本文提出了建设沈阳生态市需要更加关注和思考的几个方面。1.以人为本。2.农村是建设生态市的难点和重点。3.建立生态安全防护体系。4.实行区域环境治理。5.建设生态文化。 相似文献
857.
基于郑州市2017年1月1日—2022年2月28日环境空气细颗粒物(PM2.5)逐日质量浓度监测数据和同期气象数据,利用反向传播(BP)神经网络构建了环境空气PM2.5质量浓度预报模型,实现了对郑州市后1日环境空气PM2.5质量浓度日均值进行预报。构建了考虑大气氧化性因素(情景一)和不考虑大气氧化性因素(情景二)这2种情景,并对2种情景下的预报效果进行评价。结果显示,在情景一下,各季节PM2.5预报质量浓度与实况质量浓度的标准化平均偏差(NMB)和均方根误差(RMSE)均处于较低水平,表明预报效果均具有较好的稳定性;各季节PM2.5实况质量浓度与预报质量浓度之间的相关系数(r)、一致性指数(IA)、准确率(Q)和级别预报准确率(G)均处于较高水平,其中Q值均>79%,G值均>80%,表明各季节PM2.5实况质量浓度与预报质量浓度趋势的吻合程度较高。情景一各季节PM2.5预报质量浓度与实况质量浓度的NMB和RMSE均低于情景... 相似文献
858.
我国铁路危险货物办理站安全分析与对策 总被引:3,自引:1,他引:2
危险货物运输的源头是危险货物办理站 ,研究危险货物办理站的安全管理及存在的问题 ,具有现实意义和社会影响 ,对铁路行车安全和危货安全承运及保管至关重要。笔者通过实践和调查 ,阐述了目前我国铁路危险货物办理站安全运输中存在的主要问题 ,指出了危险货物办理站现有问题产生的原因 ,并提出了我国危险货物办理站问题解决的对策。 相似文献
859.
Pavlos D. Kalabokas Loizos G. Viras John G. Bartzis Christos C. Repapis 《Atmospheric environment (Oxford, England : 1994)》2000,34(29-30)
A systematic analysis of surface ozone observations in rural areas surrounding Athens is presented. The analysis is based on ozone data for the rural station Aliartos about 80 km NW of Athens center and for two stations on the northern periphery of the Athens basin: Demokritos, located 10 km NE of Athens center and Liossia, 12 km to the north. The data for these two stations are screened for cases of strong air flow from rural areas. Average hourly summer afternoon ozone mixing ratios are similar for all three stations about 60 ppb and thus exceed for the hours 12:00–20:00 LST the 55 ppb WHO guideline for human health for 8 h ozone exposure. The corresponding winter afternoon mixing ratios are at 35 ppb. However, due to the large diurnal variation, mean monthly ozone mixing ratios at Aliartos, for the months April–September vary from 32 to 40 ppb, which is comparable to the higher average ozone levels at rural stations in south-central Europe. In cases of southerly air flow in the summer in the Athens basin, afternoon ozone levels at Demokritos and Liossia are generally the highest of any in the monitoring network. Hourly average concentrations, however, are only 40% greater than rural values. A background ozone level of such magnitude will have a significant impact on estimates for the effectiveness of pollution control measures for Athens. 相似文献
860.
在北方农牧交错带植被重建中适宜乔、灌、草种生态区划的基础上,以该区域黄土高原区作为研究区,结合该区1989和1999两年的土地利用分类图,通过计算区域缺水指数及对其分级,探讨了缺水指数在时间和空间上的变化规律,分析了耕地、林地、草地等该区主要土地利用类型在时间和空间上与缺水指数的关系。在此基础上,构建水分亏缺风险指数(RiskIndexofWaterDeficit),从研究区整体和各生态分区两个尺度上探讨了不同土地利用类型的RIWD时空分异。得出如下结论:①1989~2000年,研究区缺水指数均在中度以上,其变化幅度有逐年减少的趋势;②对比1989年和1999年两年的缺水指数,区域整体缺水状况有所缓解,但各生态分区内的缓解程度在空间上仍存在差异;③从研究区整体而言,各土地利用类型的水分亏缺风险指数逐渐减少,依次为林地、耕地、草地;④因各生态分区内的地理特征包括水分状况存在变化,故各土地利用类型的水分亏缺风险程度排列顺序与区域整体有所不同。 相似文献