全文获取类型
收费全文 | 406篇 |
免费 | 4篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 12篇 |
环保管理 | 33篇 |
综合类 | 98篇 |
基础理论 | 97篇 |
污染及防治 | 109篇 |
评价与监测 | 23篇 |
社会与环境 | 36篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 3篇 |
2022年 | 7篇 |
2021年 | 3篇 |
2020年 | 7篇 |
2019年 | 13篇 |
2018年 | 9篇 |
2017年 | 19篇 |
2016年 | 16篇 |
2015年 | 11篇 |
2014年 | 20篇 |
2013年 | 23篇 |
2012年 | 21篇 |
2011年 | 18篇 |
2010年 | 20篇 |
2009年 | 17篇 |
2008年 | 18篇 |
2007年 | 32篇 |
2006年 | 9篇 |
2005年 | 14篇 |
2004年 | 8篇 |
2003年 | 15篇 |
2002年 | 13篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1983年 | 6篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1970年 | 2篇 |
1967年 | 2篇 |
1964年 | 3篇 |
1920年 | 3篇 |
1915年 | 1篇 |
排序方式: 共有416条查询结果,搜索用时 109 毫秒
171.
172.
Temporal Segmentation of Human Short-Term Behavior in Everyday Activities and Interview Sessions 总被引:1,自引:0,他引:1
Human behavior is structured by serial order and timing of functionally related groups of movements with a duration of a
few seconds. These elementary action units have been described in ethological studies during unstaged everyday behavior, but
not during interview sessions. Psychomotor alterations are relevant for differential diagnosis and treatment, and psychiatric
patients are generally evaluated during interview sessions. Therefore the time structure of upper limb movements (n=764) of healthy subjects (n=22) were studied using videotaped interviews and frame-by-frame analysis and compared to movements (n=530) of unstaged human everyday behavior (n=154). The number of action units, but not their duration, was correlated inversely with self-reported impairment of mood
and pleasure experience in healthy persons. The temporal distribution of movements in interview sessions did not differ from
the time patterns of everyday behavior. This method could be a promising tool to investigate time patterns of movements and
psychomotor alterations in psychiatric patients during interview sessions.
Received: 29 October 1998 / Accepted in revised form: 29 December 1998 相似文献
173.
激光诱导荧光技术测量大气OH自由基的研究进展 总被引:2,自引:0,他引:2
大气氢氧自由基(OH)是对流层大气中最重要的氧化剂,对酸雨,平流层臭氧的损耗等有重要影响,激光诱导荧光技术是目前测定大气OH自由基中使用最多的测量方法。文章总结了20多年来国内外的研究成果,论述了激光诱导荧光技术用于测定大气OH自由基的基本原理和研究进展,讨论了测量中不确定因素及其对策,并着重介绍了目前最常用的基于气体扩张的低压荧光技术。 相似文献
174.
175.
Ralf Dillert Matthias Brandt Iris Fornefett Ulrike Siebers Detlef Bahnemann 《Chemosphere》1995,30(12):2333-2341
The photocatalytic degradation of 2,4,6-trinitrotoluene and ten other nitroaromatic compounds in aerated TiO2 suspensions has been studied. The following order of reactivity was observed: nitrotoluenes > nitrobenzene > dinitrotoluenes . dinitrobenzenes > 2,4,6-trinitrotoluene > 1,3,5-trinitrobenzene, which reflects the known influence of nitro groups towards the attack of electrophilic reagents on the aromatic molecule. 相似文献
176.
177.
178.
Lucie Zvolska Matthias Lehner Yuliya Voytenko Palgan Oksana Mont Andrius Plepys 《Local Environment》2019,24(7):628-645
ABSTRACTAddressing urban sustainability challenges requires changes in the way systems of provision and services are designed, organised and delivered. In this context, two promising phenomena have gained interest from the academia, the public sector and the media: “smart cities” and “urban sharing”. Smart cities rely on the extensive use of information and communications technology (ICT) to increase efficiencies in urban areas, while urban sharing builds on the collaborative use of idling resources enabled by ICT in densely populated cities. The concepts have many similar features and share common goals, yet cities with smart city agendas often fail to take a stance on urban sharing. Thus, its potentials are going largely unnoticed by local governments. This article addresses this issue by exploring cases of London and Berlin – two ICT-dense cities with clearly articulated smart city agendas and an abundance of sharing platforms. Drawing on urban governance literature, we develop a conceptual framework that specifies the roles that cities assume when governing urban sharing: city as regulator, city as provider, city as enabler and city as consumer. We find that both cities indirectly support urban sharing through smart agenda programmes, which aim to facilitate ICT-enabled technical innovation and emergence of start-ups. However, programmes, strategies, support schemes and regulations aimed directly at urban sharing initiatives are few. We also find that Berlin is sceptical towards urban sharing organisations, while London took more of a collaborative approach. Implications for policy-makers are discussed in the end. 相似文献
179.
180.
An undisturbed natural reserve area iocated in a tropical montane rain forest at about 1800 m altitude in Sri Lanka served as a study site to investigate and assess the natural background concentration levels of As, Cd, Co, Cu, Ni, Pb and Zn in plants representing different taxonomic groups (divisions) in the plant kingdom. The plants selected were: the lichen,Usnea barbata (old man's beard);Pogonatum sp. (a moss);Lycopodium selago (epiphytic lycopod);Polypodium lanceolatum (epiphytic fern);Bulbophyllum elliae (epiphytic orchid) andActinodaphne ambigua (dicotyledonous large tree). Degree of homogeneity with respect to Cd, Cu, Pb and Zn in homogenised materials of all samples were within acceptable limits, whereasPogonatum sp. showed the highest degree of homogeneity for Pb. In addition to confirming extremely low levels of heavy metals in all plant species, the survey also found that generally the primitive plants,Usnea andPogonatum appear to have a greater tendency to accumulate As, Cd, Co and Pb; in particular,U. barbata appears to be an efficient accumulator for those heavy metals, suggesting its potential use in environmental studies.Actinodaphne ambigua was found to have a specific accumulating ability for nickel. Surface cleaning of theA. ambigua leaves resulted in a substantial decrease in the foliar contents of Cd, Ni, Pb and Zn. Variations in heavy metal contents observed in different plant genera are discussed in terms of their habits and place of growth in the forest. It is anticipated that the background levels presented in this paper from a remote, unpolluted tropical ecosystem will provide useful reference data for comparative environmental studies. 相似文献