全文获取类型
收费全文 | 17629篇 |
免费 | 1511篇 |
国内免费 | 1954篇 |
专业分类
安全科学 | 3198篇 |
废物处理 | 270篇 |
环保管理 | 3657篇 |
综合类 | 8726篇 |
基础理论 | 1560篇 |
环境理论 | 66篇 |
污染及防治 | 739篇 |
评价与监测 | 1018篇 |
社会与环境 | 1326篇 |
灾害及防治 | 534篇 |
出版年
2024年 | 39篇 |
2023年 | 207篇 |
2022年 | 335篇 |
2021年 | 499篇 |
2020年 | 549篇 |
2019年 | 512篇 |
2018年 | 442篇 |
2017年 | 778篇 |
2016年 | 835篇 |
2015年 | 834篇 |
2014年 | 807篇 |
2013年 | 1175篇 |
2012年 | 1299篇 |
2011年 | 1311篇 |
2010年 | 1052篇 |
2009年 | 1036篇 |
2008年 | 730篇 |
2007年 | 1152篇 |
2006年 | 1105篇 |
2005年 | 979篇 |
2004年 | 871篇 |
2003年 | 783篇 |
2002年 | 643篇 |
2001年 | 527篇 |
2000年 | 544篇 |
1999年 | 408篇 |
1998年 | 292篇 |
1997年 | 264篇 |
1996年 | 190篇 |
1995年 | 232篇 |
1994年 | 160篇 |
1993年 | 125篇 |
1992年 | 102篇 |
1991年 | 57篇 |
1990年 | 40篇 |
1989年 | 29篇 |
1988年 | 20篇 |
1987年 | 8篇 |
1986年 | 10篇 |
1982年 | 11篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1973年 | 6篇 |
1972年 | 9篇 |
1971年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
101.
应用灰色系统GM(1,1)模型,对地下水中总硬度的变化作了预测.检验结果表明,该模型精度较高,是一种较好的预测方法. 相似文献
102.
103.
文章就此次"一控双达标"验收监测中所反映的一些问题,提出一些观点和建议,为今后达标验收监测及环境管理提供对策. 相似文献
104.
利用面向对象技术、多线程技术和动态链接技术在嵌入式操作Windows CE上开发了移动环境监测系统。介绍了基于实时嵌入式操作的移动环境监测系统的设计原理、系统框架及关键技术。指出在嵌入式计算机上实现移动环境监测,既可以进行在线环境监测,也可以减少开发的费用和硬件投资。该系统的特点是集成度高,体积小,反应速度快,智能化高,稳定性好和可靠性强。 相似文献
105.
论中国环境监测发展战略 总被引:23,自引:10,他引:23
介绍了中国环境监测的发展历程,分析了中国环境监测发展面临的压力,提出了中国环境监测的发展战略和实现战略目标的保障措施. 相似文献
106.
107.
灰色模型在确定关键污染因子中的应用 总被引:1,自引:2,他引:1
将灰色模型引入水环境质量评价中 ,通过对某个时间段内污染物原始监测数据的灰色处理 ,从动态演变中找出关键因子 ,客观地判定各污染因子所起的作用 ,并对各因子在下一个时间段的发展趋势作出判断 ,增加了评价的准确性。经过实例运用分析表明 ,该方法物理意义明确 ,简便易用 相似文献
108.
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
109.
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
110.
IMPACTS OF VISITORS ON SOIL AND VEGETATION OF THE RECREATIONAL AREA “NACIMIENTO DEL RÍO MUNDO” (CASTILLA-LA MANCHA, SPAIN) 总被引:1,自引:0,他引:1
Andrés-Abellán M Del Alamo JB Landete-Castillejos T López-Serrano FR García-Morote FA Del Cerro-Barja A 《Environmental monitoring and assessment》2005,101(1-3):55-67
This study examines the effects of recreational use on the soil and vegetation at a site of ecological importance (Nacimiento del Río Mundo, Albacete, Spain). The most visited sites showed increased soil compaction of approximately 50%, bare ground increase to 61 ± 10% and a decrease in richness (from 25 ± 2 to 15 ± 2 species), diversity (from 4.0 ± 0.1 to 2.7 ± 0.4) and stratification of plant species (from 80 ± 11 to 21 ± 4%). The most visited sites had 90% less plant species as compared to the least visited. Intense use was associated with the presence of nitrophilous plant and vegetal species with a morphology adapted to heavy trampling. The recreational areas showed a distribution pattern of impact radiating outwards from the most used and degraded point. At the most visited point, Los Chorros (the spring of the river), the impact radiated outwards for about 20 m. A pilot experiment examining the effects of one-year restriction to visitors for access to a formerly impacted area showed a plant cover increase by anthropic and not by native species of 57 percent units. 相似文献