全文获取类型
收费全文 | 16616篇 |
免费 | 1345篇 |
国内免费 | 2082篇 |
专业分类
安全科学 | 1530篇 |
废物处理 | 240篇 |
环保管理 | 4187篇 |
综合类 | 8816篇 |
基础理论 | 1529篇 |
环境理论 | 47篇 |
污染及防治 | 742篇 |
评价与监测 | 1919篇 |
社会与环境 | 939篇 |
灾害及防治 | 94篇 |
出版年
2024年 | 82篇 |
2023年 | 236篇 |
2022年 | 312篇 |
2021年 | 431篇 |
2020年 | 455篇 |
2019年 | 415篇 |
2018年 | 398篇 |
2017年 | 707篇 |
2016年 | 756篇 |
2015年 | 801篇 |
2014年 | 797篇 |
2013年 | 1153篇 |
2012年 | 1199篇 |
2011年 | 1185篇 |
2010年 | 919篇 |
2009年 | 908篇 |
2008年 | 680篇 |
2007年 | 1054篇 |
2006年 | 1042篇 |
2005年 | 887篇 |
2004年 | 769篇 |
2003年 | 762篇 |
2002年 | 613篇 |
2001年 | 560篇 |
2000年 | 531篇 |
1999年 | 391篇 |
1998年 | 292篇 |
1997年 | 261篇 |
1996年 | 238篇 |
1995年 | 222篇 |
1994年 | 151篇 |
1993年 | 125篇 |
1992年 | 91篇 |
1991年 | 78篇 |
1990年 | 47篇 |
1989年 | 45篇 |
1988年 | 43篇 |
1987年 | 34篇 |
1986年 | 29篇 |
1985年 | 21篇 |
1984年 | 26篇 |
1983年 | 23篇 |
1982年 | 32篇 |
1981年 | 30篇 |
1980年 | 34篇 |
1979年 | 36篇 |
1978年 | 20篇 |
1977年 | 21篇 |
1975年 | 20篇 |
1973年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
81.
本文讨论了水环境数学模型的选择及在水质管理规划中的使用方法,达到实用的目的.具有广泛的通用性和实用性. 相似文献
82.
关于模糊数学在环境质量综合评判中“最大隶属度”原则不适用性的讨论 总被引:3,自引:0,他引:3
通过对模糊数学在环境质量综合评判中的分析,指出“最大隶属度”原则的不适用性,并根据环境质量分级所存在的固有关系提出改进的方法。 相似文献
83.
John Boland Olena Kravchuk Wasim Saman Rowan Kilsby 《Environmental Modeling and Assessment》2003,8(2):101-113
The provision of energy for households is a major contributor to greenhouse gas emissions in the domestic sector. There is significant scope for energy savings and thus emission reduction in this sector. This paper constructs a bridge between thermal analysis and environmental assessment in the occupancy stage of the dwelling life cycle, approaching both methods as being on a common system Environment–Dwelling–Inhabitant. The importance of the local level in the thermal analysis and assessment of either a dwelling or an inhabitant's behaviour is demonstrated. It is shown that the researcher can choose between natural experiment, computer experiment and mathematical modelling to analyze the system. Such a choice is discussed for two particular methods of thermal analysis. Thermal Nomograms are the result of mathematical modelling, and the Energy Score Sheet is the result of a computer experiment in energy rating. Despite being developed for the purpose of thermal analysis, these methods can also be utilized for environmental assessment at the local level. The discussion centres on Australian conditions where the majority of the population resides in a relatively benign climate wherein behavioural alterations have significant potential for energy savings and environmental impact. The purpose of the paper is to emphasise benefits apart from energy minimisation to promote the use of energy efficient housing strategies. 相似文献
84.
分析了模糊综合评判在水质评价中的缺陷,将模糊数学中的贴近度与经典的Euclidean距离结合,提出Euclidean贴近度水质评价法。结果表明,该评价方法具有科学性、合理性,并且精度高,简单实用。 相似文献
85.
应用模糊综合指数法对伊犁河(伊宁段)水质的综合评价 总被引:3,自引:0,他引:3
模糊数学法对伊犁河(伊宁段)水质进行综合评价时,由于分别采用地面水环境质量标准中五类标准值的平均值及其中三个标准值,计算后的结果不一致,而模糊综合指数法避免了这类问题的出现,计算结果比较满意.从而表明,该法是对模糊数学法的进一步改进. 相似文献
86.
87.
乌伦古湖水质现状及污染防治对策 总被引:7,自引:0,他引:7
着重对乌伦古湖所监测的项目作了全面系统的分析,评价了该湖的水环境质量,指出乌伦古湖水质的主要问题是严重咸化,这是该湖可持续发展的最大障碍。并指出做好湖区规划,增加水源供给,加强污水处理和湿地建设,是乌伦古湖未来发展的有利措施。 相似文献
88.
Bass B Economou V Lee CK Perks T Smith SA Yip Q 《Environmental monitoring and assessment》2003,85(2):199-219
Indoor environmental health is now recognized as an important factor in preventing respiratory health problems in the United States. It is also a concern in Canada due to the amount of time that Canadians spend indoors because of cold weather and the potential for increased time indoors during the summer if theclimate warms. The negative health effects are often labeled assick building syndrome, but diagnosing a building or itsoccupants as sick is complicated by the variety of symptoms, thepresence of chronic versus acute symptoms and social andpsychological (socio-psychological) factors that may reduce theeffectiveness of an engineering solution. As a case study, thecontribution of various factors to indoor environmental health,in three buildings at the University of Toronto, was examinedusing five different methods. The results indicate that theinhabitants of the buildings consider features other than airquality in considering building health such as design,maintenance, funding cuts and socio-psychological factors. 相似文献
89.
Graef F Schmidt G Schröder W Stachow U 《Environmental monitoring and assessment》2005,108(1-3):189-203
A representative environmental monitoring network at the regional scale cannot use raster-based or random sampling designs, but requires a stratified sampling procedure integrating different information layers, and it has to occur in ecologically differing homogeneous regions (ecoregions). These we have determined using a set of spatial strata with ecological variables which we analysed with classification and regression trees (CART). We present a framework for environmental monitoring, that covers different scales, and we transfer the framework to a potential GMO (genetically modified organisms) monitoring network. We use ecoregion and other environmental strata together with existing environmental monitoring networks to determine GMO monitoring sites more precisely. 相似文献
90.
Turalioğlu FS 《Environmental monitoring and assessment》2005,104(1-3):119-130
Sulphur dioxide and PM10 levels are investigated in Erzurum during the periods of 1990–2000 heating season to assess air pollution level. For that reason, emissions of sulphur dioxide and particulate matter were calculated by using consumption of fuels and Turkish emission factors. These emission values were evaluated together with air pollution levels, which were measured at six stations in Erzurum atmosphere during 1990–2000 winter periods. Results reveal that in 1990–1994 heating period, there is an increasing trend in the emissions and air pollution levels over Erzurum, and the air quality limits were not met. The daily 24 h limit (short-term limit) was exceeded 127 days in 1992–1993 winter period. The reason for this increase was found to be the switching to use of low-quality fossil fuels instead of cleaner ones. Results also indicated that there was a considerable decrease in emissions of air pollutants and air pollution levels after 1995. This can be explained by the consumption of more high-quality fossil fuels. The correlation coefficient of SO2 with PM10 is obtained as r2 = 0.85, which is a high value supporting the idea that both pollutants are emitted from the same source. 相似文献