首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   203篇
  免费   2篇
  国内免费   3篇
安全科学   20篇
废物处理   1篇
环保管理   19篇
综合类   85篇
基础理论   13篇
污染及防治   12篇
评价与监测   29篇
社会与环境   5篇
灾害及防治   24篇
  2022年   3篇
  2021年   4篇
  2020年   2篇
  2019年   1篇
  2018年   3篇
  2017年   4篇
  2016年   4篇
  2015年   8篇
  2014年   11篇
  2013年   18篇
  2012年   7篇
  2011年   10篇
  2010年   4篇
  2009年   21篇
  2008年   16篇
  2007年   10篇
  2006年   2篇
  2005年   7篇
  2004年   6篇
  2003年   2篇
  2002年   4篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1998年   2篇
  1997年   2篇
  1995年   5篇
  1994年   5篇
  1993年   7篇
  1992年   9篇
  1991年   6篇
  1990年   3篇
  1989年   3篇
  1987年   5篇
  1985年   3篇
  1984年   4篇
  1983年   1篇
  1982年   1篇
排序方式: 共有208条查询结果,搜索用时 250 毫秒
81.
酚污染正严重威胁着饮用水源地的供水安全,迫切需要开展挥发酚实时预警监测。从挥发酚在线监测系统构架、监测方法验证、在线监测功能完善、运维周期及成本核算、应急预警功能实现等方面,介绍了挥发酚在线监测技术在苏州市饮用水源地的应用经验,以期进一步完善水源水预警监测体系。  相似文献   
82.
Effluents from wastewater treatment plants (WWTPs) containing microorganisms and residual nutrients can influence the biofilm formation. Although the process and mechanism of bacterial biofilm formation have been well characterized, little is known about the characteristics and interaction of bacteria, archaea and eukaryotes in the early colonization, especially under the influence of WWTP effluent. The aim of this study was to characterize the important bacterial, archaeal and eukaryotic species in the early stage of biofilm formation downstream of the WWTP outlet. Water and biofilm samples were collected 24 and 48 hr after the deposition of bio-cords in the stream. Illumina Miseq sequencing of the 16S and 18S rDNA showed that, among the three domains, the bacterial biofilm community had the largest alpha and beta diversity. The early bacterial colonizers appeared to be “biofilm-specific”, with only a few dominant operational taxonomic units (OTUs) shared between the biofilm and the ambient water environment. Alpha-proteobacteria and Ciliophora tended to dominate the bacterial and eukaryotic communities, respectively, of the early biofilm already at 24 hr, whereas archaea played only a minor role during the early stage of colonization. The network analysis showed that the three domains of microbial community connected highly during the early colonization and it might be a characteristic of the microbial communities in the biofilm formation process where co-occurrence relationships could drive coexistence and diversity maintenance within the microbial communities.  相似文献   
83.
以核电站核污染扩散预警技术为研究对象,基于环保指挥自动化系统C4ISRE,通过整合WRF、HYSPLIT、Unidata IDV、AGI STK、Arc GIS系统等构建核污染扩散单一合成图SIP(Single Integrated Picture),并通过SIP对核污染扩散进行详细分析,进而实现对核污染应急处置的制信息权。研究表明:当研究区实际的天气系统具备了本例模拟的气象特征时,即主体风向为局部区域东北风3~4级,局部区域西北风6~7级,发生与日本福岛核事故同样等级的事故,12个小时后,受影响的居民区主要为谢屯镇、炮台镇、李店镇、普兰店市、无名区1。其中,炮台镇的大部分区域浓度为10 Pbq,面积为2.66 km 2,东北方向部分区域浓度为100 Pbq,面积为0.03 km~2;普兰店市西南部区域浓度为10 Pbq,面积为8.00 km~2,东北部区域浓度为100 Pbq,面积为0.033 km 2;李店镇东北区域浓度为1 Pbq,面积为0.93km~2;无名区1南部区域浓度为1 Pbq,面积为4.50 km~2。  相似文献   
84.
Louise Sperling 《Disasters》1987,11(4):263-272
In 1983 and 1984, drought spread across the northern rangelands of Kenya and herders in lowland Samburu lost substantial portions of their livestock. Food aid arrived when 50 to 75% of the cattle had already died, and after poorer pastoralists were hungry enough to sell their remaining productive animals. No pastoralists died of the immediate effects of the drought, but many were so impoverished that their longer-term prospects for remaining as herders look dim.
This essay discusses the timing and content of famine relief as it applies both to Samburu and other food-stressed areas. It focuses on the process of food acquisition during the northern Kenyan drought itself. The more "indigenous" food strategies of herding, hunting and gathering offered limited benefits. Equally, however, commercial channels for procuring food proved inadequate. Herders could not reliably sell animals to obtain cash for purchased food, nor were the grain and sugar staples always available even when cash was on hand. Lacking means to provide for themselves, Samburu came to depend on varied kinds of handouts.  相似文献   
85.
以下扬子区44个代表性剖面的资料为基础,求导佩尔特提出的D函数和熵函数,编制出早石炭世各时期的沉积厚度趋势图和佩尔特岩相图,研究其沉积特征和古地理,对阐明该区地质发展史和地层控矿条件提供空间分布上的有用信息。  相似文献   
86.
Chorion biopsy specimens were used for prenatal assay of arylsulphatase A activity in a pregnant woman whose two children had died from metachromatic leukodystrophy (MLD). As in two subsequent pregnancies chorion arylsulphatase A was in the control range, it was concluded that both fetuses were healthy. Absence of MLD in the fetus from the first pregnancy was confirmed after assay of arylsuphatase A activity in fetal organs. The second pregnancy resulted in delivery of a healthy child.  相似文献   
87.
环境科学涉及到诸多领域,相关学科间的交叉、融合使环境科学研究日趋复杂,这种复杂性在大范围、长时间的环境研究中表现得尤为突出。对这类复杂的大区域的环境研究要从指导思想、研究方法、研究策略上进行改进,要从根本上寻求解决之道。笔者首先阐述了大区域环境研究的复杂性,探讨了研究的理论基础,最后以大徐州地区的环境问题为例,提出了研究策略。  相似文献   
88.
室内空气污染及控制   总被引:4,自引:0,他引:4  
室内空气污染是伴随着生活水平提高而出现的一b个崭新问题,与人类健康、生存有着密切的关系.本文着重介绍了甲醛、氯仿、三氯乙烯和燃烧产物等几种常见的室内污染物的来源、危害及预防措施.  相似文献   
89.
Cacops, one of the most distinctive Paleozoic amphibians, is part of a clade of dissorophoid temnospondyls that diversified in the equatorial region of Pangea during the Late Carboniferous and Early Permian, persisting into the Late Permian in Central Russia and China. Dissorophids were a successful group of fully terrestrial, often spectacularly armoured predators, the only amphibians apparently able to coexist with amniotes when the latter started to dominate terrestrial ecosystems. In this paper, we describe excellent new skulls from the Early Permian of Oklahoma attributed to Cacops, Cacops morrisi sp. nov. and provide for the first time detailed information about this iconic dissorophid. These specimens show anatomical and ontogenetic features that will impact on future studies on the evolution of terrestriality in tetrapods. For example, the large, posteriorly closed tympanic embayment has fine striations on an otherwise smooth surface, documenting the oldest known clear evidence for the presence of a tympanic membrane in the fossil record, a structure that is used for hearing airborne sound in extant tetrapods. The skull of C. morrisi also has several features associated with predatory behaviour, indicating that this dissorophid may have been one of the top terrestrial predators of its time.  相似文献   
90.
在经济快速发展与工业进程加快的推动下,人们生活条件得到改善。然而,大气污染问题也随之加剧,使城市形象受到严重损害,并阻碍城市发展与进步。相关部门需要对此种问题加以重视,积极制定防治措施。本文对大气污染危害与成因进行简单分析,并对其治理创新模式和方法进行简单介绍。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号