全文获取类型
收费全文 | 18888篇 |
免费 | 898篇 |
国内免费 | 5606篇 |
专业分类
安全科学 | 1340篇 |
废物处理 | 1183篇 |
环保管理 | 1570篇 |
综合类 | 9834篇 |
基础理论 | 3155篇 |
环境理论 | 2篇 |
污染及防治 | 5882篇 |
评价与监测 | 968篇 |
社会与环境 | 769篇 |
灾害及防治 | 689篇 |
出版年
2024年 | 27篇 |
2023年 | 261篇 |
2022年 | 835篇 |
2021年 | 749篇 |
2020年 | 589篇 |
2019年 | 529篇 |
2018年 | 716篇 |
2017年 | 761篇 |
2016年 | 751篇 |
2015年 | 964篇 |
2014年 | 1358篇 |
2013年 | 1851篇 |
2012年 | 1449篇 |
2011年 | 1538篇 |
2010年 | 1285篇 |
2009年 | 1276篇 |
2008年 | 1372篇 |
2007年 | 1184篇 |
2006年 | 1139篇 |
2005年 | 755篇 |
2004年 | 614篇 |
2003年 | 667篇 |
2002年 | 596篇 |
2001年 | 588篇 |
2000年 | 577篇 |
1999年 | 452篇 |
1998年 | 342篇 |
1997年 | 378篇 |
1996年 | 319篇 |
1995年 | 261篇 |
1994年 | 213篇 |
1993年 | 181篇 |
1992年 | 159篇 |
1991年 | 105篇 |
1990年 | 95篇 |
1989年 | 58篇 |
1988年 | 49篇 |
1987年 | 38篇 |
1986年 | 33篇 |
1985年 | 24篇 |
1984年 | 25篇 |
1983年 | 30篇 |
1982年 | 35篇 |
1981年 | 24篇 |
1980年 | 11篇 |
1979年 | 14篇 |
1978年 | 12篇 |
1975年 | 12篇 |
1973年 | 9篇 |
1972年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
121.
大气中SO_2、NO_x、TSP和CO平行采样监测结果的统计分析表明,地面与楼顶采样的差异不显著,其浓度变化有随高度呈规律性的变化趋向,降雪具有明显的洗脱清除作用。 相似文献
122.
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
123.
Assessing land use impacts on flood processes in complex terrain by using GIS and modeling approach 总被引:1,自引:0,他引:1
Y. B. Liu F. De Smedt L. Hoffmann L. Pfister 《Environmental Modeling and Assessment》2005,9(4):227-235
A distributed hydrologic modeling and GIS approach is applied for the assessment of land use impact in the Steinsel sub-basin, Alzette, Grand-Duchy of Luxembourg. The assessment focuses on the runoff contributions from different land use classes and the potential impact of land use changes on runoff generation. The results show that the direct runoff from urban areas is dominant for a flood event compared with runoff from other land use areas in this catchment, and tends to increase for small floods and for the dry season floods, whereas the interflow from forested, pasture and agricultural field areas contributes to the recession flow. Significant variations in flood volume, peak discharge, time to the peak, etc., are found from the model simulation based on the three hypothetical land use change scenarios. 相似文献
124.
Pacáková V Pockeviciute D Armalis S Stulík K Li J Veselý J 《Journal of environmental monitoring : JEM》2000,2(2):187-191
Experiments were carried out to monitor the equilibrium distribution of lead, cadmium and copper between an aqueous phase modelling natural water and a solid phase modelling natural sediment, under varying conditions. The aqueous phase was analysed using ETAAS and differential pulse anodic stripping voltammetry (DPASV), whereas XRD and FTIR were used to study the solid phase. Sorption isotherms at constant pH were measured. Conditional distribution constants were calculated as functions of the pH, the time of equilibration and the amount of solid material. The results obtained stress the need for standardization of the approaches to the study of water-sediment interactions in order to be able to evaluate and compare the extensive data from field measurements and to predict these interactions. 相似文献
125.
Iwasaka Y Shi GY Kim YS Matsuki A Trochkine D Zhang D Yamada M Nagatani T Nagatani M Shen Z Shibata T Nakata H 《Environmental monitoring and assessment》2004,92(1-3):5-24
Measurements of aerosols were made in 2001 and 2002 at Dunhuang (40 degrees 00'N, 94 degrees 30'E), China to understand the nature of atmospheric particles over the desert areas in the Asian continent. Balloon-borne measurements with an optical particle counter suggested that particle size and concentration had noticeable peaks in super micron size range not only in the boundary mixing layer but also in the free troposphere. Super-micron particle concentration largely decreased in the mid tropopause (from 5 to 10 km; above sea level, a.s.l.). Lidar measurements made during August 2002 at Dunhuang suggested the possibility that mixing of dust particles occurred from near the ground to about 6 km even under calm weather conditions, and a large depolarization ratio of particulate matter was found in the aerosol layer. The top of the aerosol layer was found at heights of nearly 6 km (a.s.l.). It is strongly suggested that nonspherical dust particles (Kosa particles) frequently diffused in the free atmosphere over the Taklamakan desert through small-scale turbulences and are possible sources of dust particles of weak Kosa events that have been identified in the free troposphere not only in spring but also in summer over Japanese archipelago. Electron microscopic experiments of the particles collected in the free troposphere confirmed that coarse and nonspherical particles observed by the mineral particle were major components of coarse mode (diameter larger than 1 microm) below about 5 km over Dunhuang, China. 相似文献
126.
127.
128.
介绍液相化学发光分析法的原理和特点以及十年来在我国环境监测中的应用。收录1983年~1991年国内的应用论文50余篇,作了较为系统全面的评述。 相似文献
129.
多介质环境目标值的应用 总被引:1,自引:0,他引:1
本文概述了多介质目标德的SAM/Ⅰ的方法。多介质目标值包括环境目标值和排放目标值。点源分析包括SAM/ⅠA,SAM/ⅠB,SAM/Ⅰ,SAM/Ⅱ。在缺少环境质量标准的情况下,使用多介质环境目标值有较强的适用性,且具有省时、省力、经济等特点。本文将多介质目标值的SAM/ⅠA点源分析方法引入聚氯乙烯生产废水的环境评价中,取得较为满意的结果。 相似文献
130.
地震安全性评价工作在城市建设中起着非常重要的作用,为工程抗震提供精确的设计依据,提供科学合理的地震动参数,提出科学合理的设防要求,能够在一定程度上避免破坏性地震造成的损失,从而达到有效减灾的目的。 相似文献