全文获取类型
收费全文 | 716篇 |
免费 | 5篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 10篇 |
废物处理 | 31篇 |
环保管理 | 62篇 |
综合类 | 150篇 |
基础理论 | 168篇 |
环境理论 | 4篇 |
污染及防治 | 232篇 |
评价与监测 | 38篇 |
社会与环境 | 35篇 |
出版年
2023年 | 9篇 |
2022年 | 8篇 |
2021年 | 10篇 |
2020年 | 10篇 |
2019年 | 4篇 |
2018年 | 24篇 |
2017年 | 14篇 |
2016年 | 13篇 |
2015年 | 17篇 |
2014年 | 23篇 |
2013年 | 52篇 |
2012年 | 25篇 |
2011年 | 54篇 |
2010年 | 31篇 |
2009年 | 43篇 |
2008年 | 34篇 |
2007年 | 44篇 |
2006年 | 33篇 |
2005年 | 22篇 |
2004年 | 35篇 |
2003年 | 23篇 |
2002年 | 27篇 |
2001年 | 15篇 |
2000年 | 11篇 |
1999年 | 6篇 |
1998年 | 16篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 6篇 |
1994年 | 10篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1981年 | 4篇 |
1978年 | 3篇 |
1974年 | 3篇 |
1965年 | 3篇 |
1963年 | 3篇 |
1962年 | 2篇 |
1961年 | 2篇 |
1960年 | 3篇 |
1959年 | 2篇 |
1958年 | 4篇 |
1957年 | 6篇 |
1956年 | 5篇 |
1955年 | 8篇 |
1943年 | 3篇 |
1922年 | 3篇 |
排序方式: 共有730条查询结果,搜索用时 78 毫秒
101.
102.
103.
104.
Tobias Frische Jan Ahlers Andreas Gies Carola Kussatz Christoph Schulte Hans -Christian Stolzenberg 《Environmental Sciences Europe》2007,19(1):49-61
This contribution highlights the role and importance of ecotoxicology in regulatory decisions of chemicals legislation focussing on the responsibilities of the German Federal Environmental Agency (UBA). Therefore, organisational structures and processes relevant for making decisions concerning the risks of chemicals to men and the environment are described. As any regulatory decision starts with scientific findings, a brief overview of UBA’s activities with regard to own research and to initiate research in the area of ecotoxicology is provided. In addition, the vast importance of standardisation and international harmonisation of guidelines for testing and assessment of chemicals is illustrated, including the time- and ressource consuming character of these harmonisation processes. Subsequently, the involvement of regulatory decision making in intense and controversial scientific and political debates is emphasised. The transparency of these discussions and the independence of science is critically addressed in this context. In a final chapter the job requirements and options for qualification in Germany are described, ending up with a brief summary of the positive experiences with UBA’s contribution to the new advanced training course in ecotoxiciology realised by GDCh/SETAC GLB. A summary of the discussions on these different topics emphasises the specific challenge in regulatory ecotoxicology: To generate knowledge relevant for decision making, while acting in an area of conflict between scientific demands and economical as well as political interests. 相似文献
105.
Goal and Scope
The constant increase of traffic and the rising energy and material consumption both in industry and trade as well as in private households mean a constant challenge to environmental protection and to the air pollution control. With the commencement of the Federal ambient pollution control act in April 1974, the legal basis for the monitoring of air pollution was created. In future, the limit values laid down in the Council Directive 1999/30/EG, 2000/69/EG and 96/62/EG, will be valid. In town and regional planning there is a great demand for a simple index to evaluate the air quality. From the available data of PM10, NO2, O3, CO, SO2, trends of the air quality will be derived.Methods
The indices LQI and TLQ suggested by Mayer et al. (2002) were calculated for selected stations of the air pollution monitoring network (ZIMEN) in Rhineland-Palatine. All analysis are based on hourly recorded value, Mean values and frequency distributions are used for the interpretation. Furthermore, the characteristics and trends of the indices under different weather conditions were examined and discussed.Results
The examination figures out that the air pollutions indices at all stations show similar patterns in the period between January 2001 and December 2002. Neither the LQI, nor the TLQ shows an annual variation. Existing variations are mainly controlled by the general weather situation and the air temperature. High values of the indices appear at extremely high or low mean daily air temperature. The absolute value of the air pollution index is determined by local pollution factors.Outlook and Recommendations
Both indices are well suitable to evaluate the air quality and to assess the effects of state-aided measures for air pollutant control. Therefore, the indices TLQ and LQI should be published as an additional information in the world wide web. 相似文献106.
107.
108.
109.
110.
Paper nests of social wasps are intriguing constructions for both, biologists and engineers. We demonstrate that moisture
and latent heat significantly influence the thermal performance of the nest construction. Two colonies of the hornet Vespa crabro were investigated in order to clarify the relation of the temperature and the moisture regime inside the nest. Next to fairly
stable nest temperatures the hornets maintain a high relative humidity inside the nest. We found that in consequence a partial
vapor-pressure gradient between nest and ambient drives a constant vapor flux through the envelope. The vapor flux is limited
by the diffusion resistance of the envelope. The driving force of vapor flux is heat, which is consumed through evaporation
inside the nest. The colony has to compensate this loss with metabolic heat production in order to maintain a stable nest
temperature. However, humidity fluctuations inside the nest induce circadian adsorption and desorption cycles, which stabilize
the nest temperature and thus contribute significantly to temperature homeostasis. Our study demonstrates that both mechanisms
influence nest thermoregulation and need to be considered to understand the thermodynamic behavior of nests of wasps and social
insects in general. 相似文献