全文获取类型
收费全文 | 19034篇 |
免费 | 1462篇 |
国内免费 | 2841篇 |
专业分类
安全科学 | 2759篇 |
废物处理 | 271篇 |
环保管理 | 2616篇 |
综合类 | 10370篇 |
基础理论 | 2009篇 |
环境理论 | 12篇 |
污染及防治 | 1177篇 |
评价与监测 | 1474篇 |
社会与环境 | 1597篇 |
灾害及防治 | 1052篇 |
出版年
2024年 | 49篇 |
2023年 | 231篇 |
2022年 | 426篇 |
2021年 | 573篇 |
2020年 | 555篇 |
2019年 | 503篇 |
2018年 | 469篇 |
2017年 | 624篇 |
2016年 | 736篇 |
2015年 | 802篇 |
2014年 | 831篇 |
2013年 | 1046篇 |
2012年 | 1272篇 |
2011年 | 1429篇 |
2010年 | 1029篇 |
2009年 | 1044篇 |
2008年 | 858篇 |
2007年 | 1303篇 |
2006年 | 1324篇 |
2005年 | 1056篇 |
2004年 | 894篇 |
2003年 | 1033篇 |
2002年 | 824篇 |
2001年 | 709篇 |
2000年 | 641篇 |
1999年 | 585篇 |
1998年 | 439篇 |
1997年 | 351篇 |
1996年 | 295篇 |
1995年 | 263篇 |
1994年 | 252篇 |
1993年 | 205篇 |
1992年 | 163篇 |
1991年 | 125篇 |
1990年 | 94篇 |
1989年 | 50篇 |
1988年 | 46篇 |
1987年 | 28篇 |
1986年 | 20篇 |
1985年 | 29篇 |
1984年 | 15篇 |
1983年 | 18篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 9篇 |
1979年 | 11篇 |
1977年 | 11篇 |
1973年 | 10篇 |
1972年 | 5篇 |
1971年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Kimpo metropolitan landfill has received various kinds of wastessince January 1992. The leachate level was measured to be 10.3 m in May 1995 and the level increased to 12.2 m in August 1996. Therefore, to prove the reason for the increasing leachate level, we calibrated hydraulic conductivity of each waste andintermediate layer using the HELP (Hydrologic Evaluation ofLandfill Performance) model. The leachate generation data measured from February 1993 to October 1995 was used in the model calibration. As a result of a model calibration, we obtained anaverage infiltration ratio and used this in analysis of the total water balance to predict elevation of leachate level. Main causes of the elevation of the leachate level were the high water content of the waste and the degradation of the leachate-drainage system caused by the subsidence of a naturalbarrier layer. 相似文献
103.
Fagundez LA Fernández VL Marino TH Martín I Persano DA Rivarola Y Benítez M Sadañiowski IV Codnia J Zalts A 《Environmental monitoring and assessment》2001,71(1):61-70
Passive diffusion samplers were employed in San Miguel(Buenos Aires Metropolitan Area) for a preliminary airpollution monitoring. The highest loads were observedin downtown, compared with an urban background site.Total suspended particulate matter (TSPM) varied from0.257 to 0.033 mg cm-2 month-1; dust was examinedfor particle nature and size distribution. A similartrend was observed for nitrogen dioxide (NO2) andTSPM spatial distribution, suggesting that traffic isthe major pollution source. Sulphur dioxide (SO2)values were low and rather homogeneous. Levels for theinvestigated pollutants are below EPA's guide linevalues. Geographic (flat area, near to Rio de LaPlata) and climatologic factors (rainfalls andvariable wind directions) contribute to disperse pollutants. 相似文献
104.
Ambient Air Quality Monitoring Network Design for Assessing Human Health Impacts from Exposures to Airborne Contaminants 总被引:1,自引:0,他引:1
Existing methods of establishing ambientair quality monitoring networks typically evaluateonly parameters related to ambient concentrations ofthe contaminant(s) of interest such as emissionsource characteristics, atmospheric transport anddispersion, secondary reactions, depositioncharacteristics, and local topography. However,adverse health risks from exposures to airbornecontaminants are a function of the contaminant andthe anatomic and physiologic characteristics of theexposed population. Thus, ambient air qualitymonitoring networks designed for the protection ofpublic health or for epidemiological studiesevaluating adverse health impacts from exposures toambient air contaminants should account for bothcontaminant characteristics and human healthparameters. A methodology has been establishedwhich optimizes ambient air quality monitoringnetworks for assessments of adverse human healthimpacts from exposures to airborne contaminants byincorporating human health risk assessmenttechniques. The use of risk assessment techniquesas the basis for designing ambient air qualitymonitoring networks will help to target limitedfinancial and human resources to evaluate humanhealth risks from exposures to airbornecontaminants. 相似文献
105.
A study on the orbit of air temperature movement 总被引:1,自引:0,他引:1
Zong-Chang Yang 《Environmental Modeling and Assessment》2007,12(2):131-143
In this paper, we describe an air temperature movement by mapping its time series to the polar coordinates: the value of the
time series is plotted on the radial coordinate and the time on the angular coordinate. In this way, both the yearly and daily
air temperature movements from five different locations of China are used to demonstrate that, in an intuitionistic view,
air temperature movement is neither random nor chaotic, but has its own orbit. We then propose an elliptic orbit model for
the air temperature movement. Our proposed model provides quite good results when it is applied to the evaluation of yearly
air temperature movements in eight locations in various parts of the world, and the evaluation of daily air temperature movements
in five locations in Hunan Province of China on December 17, 2005. Results show that our approach provides a concise and helpful
model for air temperature analysis. 相似文献
106.
博斯腾湖水质矿化度模型及预测研究 总被引:6,自引:0,他引:6
根据博斯腾湖1985~1995年水质监测数据和出入湖水量等水文数据观测值,采用水质扩散模型和盐量平衡关系推导出博斯腾湖大湖区(简称博湖)水质矿化度模型,并预测了几种情况下博湖水质矿化度及近几年变化趋势,分析了影响博湖水质矿化度的主要因素,为博湖的近期和远期环境保护规划、环境管理等提供科学依据. 相似文献
107.
分析了建立锡山市跨行政区水域边界监控点的必要和可行性,并阐述了建立锡山市排污总量控制体系的重要性,以便提高整个区域的水环境质量。 相似文献
108.
用StrandenE.推荐的测量方法对哈密地区环境空气中220Rn子体α潜能浓度测量结果表明,室内、外平均值分别为56.1和10.2(×10-7J·m-3)。室内外220Rn/222Rn子体α潜能浓度比值分别为0.84和032。220Rn子体所致居民有效剂量当量为228μSv·a-1(集体有效剂量当量为0.9×02man·Sv)。 相似文献
109.
根据塔里木油田1993-1996年环境空气监测数据,对其环境空气质量状况进行了分析和评价。 相似文献
110.
对北京中央电视塔周围25 km2区域电磁环境质量分别进行了射频的网格法手工监测和车载巡测自动监测,通过SPSS软件等对两种监测方法获取的数据进行了统计对比分析,发现两组数据在总体水平及数值分布特征上较为接近,因此车载巡测监测可以替代网格法监测。以车载巡测数据为基础,绘制了实测数据的道路电磁地图,利用插值法绘制了区域电磁地图,对区域电磁环境质量进行了直观表征。从回应公众关注和城市电磁规划出发,建议今后可利用车载巡测监测加强时域和频域的监测。 相似文献