全文获取类型
收费全文 | 1843篇 |
免费 | 279篇 |
国内免费 | 649篇 |
专业分类
安全科学 | 401篇 |
废物处理 | 41篇 |
环保管理 | 140篇 |
综合类 | 1367篇 |
基础理论 | 269篇 |
污染及防治 | 259篇 |
评价与监测 | 94篇 |
社会与环境 | 116篇 |
灾害及防治 | 84篇 |
出版年
2024年 | 17篇 |
2023年 | 57篇 |
2022年 | 160篇 |
2021年 | 171篇 |
2020年 | 157篇 |
2019年 | 101篇 |
2018年 | 121篇 |
2017年 | 136篇 |
2016年 | 108篇 |
2015年 | 157篇 |
2014年 | 123篇 |
2013年 | 204篇 |
2012年 | 197篇 |
2011年 | 194篇 |
2010年 | 143篇 |
2009年 | 122篇 |
2008年 | 114篇 |
2007年 | 103篇 |
2006年 | 97篇 |
2005年 | 66篇 |
2004年 | 46篇 |
2003年 | 31篇 |
2002年 | 25篇 |
2001年 | 28篇 |
2000年 | 19篇 |
1999年 | 18篇 |
1998年 | 13篇 |
1997年 | 7篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 8篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1972年 | 1篇 |
1931年 | 1篇 |
排序方式: 共有2771条查询结果,搜索用时 328 毫秒
991.
992.
993.
5 A分子筛气相色谱法测定痕量 CFC12 总被引:2,自引:0,他引:2
采用5A分子筛气相色谱电子捕获检测器测定气体样品中的CFC12,介绍了填充柱的制备方法。方法线性良好,用峰高定量略优于用峰面积,检出限为27μg/m^3(进样体积以1 mL计),标准样品测定的RSD≤6.7%,加标回收率为92.3%~103%。 相似文献
994.
995.
H. H. Chang H. H. Tung C. C. Chao G. S. Wang 《Environmental monitoring and assessment》2010,162(1-4):237-250
In this study, water samples were collected from 86 water treatment plants for analysis of haloacetic acids (HAAs) and trihalomethanes (THMs) from February to March, 2007 and from July to August, 2007. Both seasonal and geographical variations of disinfection by-products (DBPs) in drinking water of Taiwan were presented. The results showed that the five HAA concentrations (HAA5) were 1.0–38.9 μg/L in the winter and 0.2–46.7 μg/L in the summer; and the total THMs were ND-99.4 μg/L in the winter and ND-133.2 μg/L in the summer. For samples taken from the main Taiwan island, dichloroacetic acid (29.4–31.7%) and trichloroacetic acid (25.3–27.6%) were the two major HAA species, and trichloromethane was the major THM species (49.9–62.2%) in finished water. For water treatment plants located on the offshore islands outside of Taiwan, high bromide concentration was found in raw water, and higher percentage of brominated THMs and HAAs were formed in the overall formation. A statistically significant (P?<?0.005) logarithmic linear regression model was found to be useful to describe the correlations between TTHM and HAA5 or nine HAAs (HAA5?=?1.219 ×TTHM 0.754, R 2?=?0.658; HAA9?=?1.824 ×TTHM 0.735, R 2?=?0.678). No apparent difference was observed for DBPs concentrations between finished water and distribution samples in this study. 相似文献
996.
Using the analytical hierarchy process to assess the environmental vulnerabilities of basins in Taiwan 总被引:3,自引:0,他引:3
Every year, Taiwan endures typhoons and earthquakes; these natural hazards often induce landslides and debris flows. Therefore,
watershed management strategies must consider the environmental vulnerabilities of local basins. Because many factors affect
basin ecosystems, this study applied multiple criteria analysis and the analytical hierarchy process (AHP) to evaluate seven
criteria in three phases (geographic phase, hydrologic phase, and societal phase). This study focused on five major basins
in Taiwan: the Tan-Shui River Basin, the Ta-Chia River Basin, the Cho-Shui River Basin, the Tseng-Wen River Basin, and the
Kao-Ping River Basin. The objectives were a comprehensive examination of the environmental characteristics of these basins
and a comprehensive assessment of their environmental vulnerabilities. The results of a survey and AHP analysis showed that
landslide area is the most important factor for basin environmental vulnerability. Of all these basins, the Cho-Shui River
Basin in central Taiwan has the greatest environmental vulnerability. 相似文献
997.
Assessment of groundwater vulnerability in the Yinchuan Plain,Northwest China using OREADIC 总被引:13,自引:0,他引:13
Groundwater vulnerability assessments provide a measure of the sensitivity of groundwater quality to an imposed contaminant
load and are globally recognized as an essential element of all aquifer management and protection plans. In this paper, the
vulnerability of groundwaters underlying the Yinchuan Plain of Northwest China is determined using OREADIC, a GIS-based assessment
tool that incorporates the key characteristics of the universally popular DRASTIC approach to vulnerability assessment but
has been modified to consider important additional hydrogeological factors that are specific to the region. The results show
that areas of high vulnerability are distributed mainly around Qingtongxia City, Wuzhong City, Lingwu City, and Yongning County
and are associated with high rates of aquifer recharge, shallow depths to the water table, and highly permeable aquifer materials.
The presence of elevated NO3− in the high vulnerability areas endorses the OREADIC approach. The vulnerability maps developed in this study have become
valuable tools for environmental planning in the region and will be used for predictive management of the groundwater resource. 相似文献
998.
新疆城市环境空气PM_(10)自动监测仪器质控巡检工作探析 总被引:1,自引:0,他引:1
随着城市环境空气质量自动监测业务现代化的飞速发展,新疆城市共安装38套PM10环境空气自动监测系统。本文通过对新疆19个城市空气自动监测系统PM10的巡检和质控考核,发现近几年来该系统运行维护中的诸多问题,从而提出仪器维护注意事项,以期提高新疆城市PM10监测数据质量,准确反映环境空气质量状况,为环境管理和政府决策提供更加科学、准确、可靠的基础监测数据。 相似文献
999.
泥石流堵塞坝溃决模式实验 总被引:4,自引:1,他引:3
为了研究泥石流堵塞坝溃决的模式,采用模型实验对堵塞坝溃决的过程进行模拟,实验历时2个月,共13组.实验中,通过改变主沟的水力参数和坝体参数研究泥石流堵塞坝溃决的全过程,并作了相关记录.通过对理论和实验数据的分析,泥石流堵塞坝的溃决形式有3种:冲刷溃决、有表面流的泥石流堆积体水力再启动、没有表面流的泥石流堆积体重力再启动.讨论了冲刷溃决中颗粒启动和有面流泥石流水力再启动的临界条件,并分析了启动流速u0和颗粒粒径D之间的关系;分析了泥石流重力再启动时堵塞坝坡面破坏的一般形式和特征;通过实验数据对不同溃决形式的溃决条件进行了验证,结果比较吻合. 相似文献
1000.
云南普洱6.4级地震震害分析 总被引:5,自引:1,他引:4
2007年6月3日云南普洱发生6.4级地震,震源深度仅5km。地震对当地各类建筑物和构筑物造成不同程度的破坏。本文根据此次地震现场调研,介绍了地震烈度分布与震区破坏等级划分,归纳了土木、砖木、砖混、框架结构房屋等建筑结构的震害情况,同时对供排水、交通、电力、通讯系统及水利工程等基础设施的破坏状况加以概括,并对各类结构的破坏原因进行了分类分析。总结了此次地震的震害特点,提出了未来村镇防震减灾工作的若干建议。 相似文献