全文获取类型
收费全文 | 234篇 |
免费 | 2篇 |
专业分类
安全科学 | 1篇 |
废物处理 | 9篇 |
环保管理 | 19篇 |
综合类 | 28篇 |
基础理论 | 38篇 |
污染及防治 | 88篇 |
评价与监测 | 27篇 |
社会与环境 | 22篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 2篇 |
2018年 | 10篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 18篇 |
2012年 | 18篇 |
2011年 | 18篇 |
2010年 | 10篇 |
2009年 | 17篇 |
2008年 | 13篇 |
2007年 | 18篇 |
2006年 | 19篇 |
2005年 | 6篇 |
2004年 | 11篇 |
2003年 | 9篇 |
2002年 | 5篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
排序方式: 共有236条查询结果,搜索用时 15 毫秒
231.
False negative detections may bias the surveys for rare species and reduce the reliability of models based on the proportion
of occupied patches. We assessed the detectability of the Eurasian otter Lutra lutra through the standard survey method by analysing the detection history of 28 sampling stretches surveyed monthly between March
2001 and January 2003. Each survey negative for otter spraints was considered as a false negative if the otter had been recorded
in the previous and/or following month (respectively, cFN and FN). Otter marking intensity (MI) (MI=N° of spraints per kilometre)
was calculated and assumed to represent an index of its relative abundance. Spraints were found in 81.7% of all surveys. Yearly
MI ranged from 1.02 to 101.4 spraints per kilometre. In 2002, mean MI was significantly lower than in the previous year, while
no clear seasonal trend could be outlined. The minimum number of surveys required to establish the occurrence of the otter,
as estimated by a probability model, was 2.6 and was inversely related to MI. For a sub-sample of 18 sampling stretches, the
relation between the frequency of both cFN and FN and five variables of potential interest for otters was tested by means
of stepwise linear multiple regressions, yielding two highly significant models, which both included only MI as the explanatory
variable. The frequency of both FN and cFN was correlated to MI and the resulting equations used to assess the percentage
of surveys positive for otters in both years. After the correction for non-detections, otter site occupancy did not vary between
the 2 years, except for one river when applying the more conservative estimate of false negatives (cFN). Multiple visits and
the assessing of MI should become standard components of otter surveys. This approach has broad applicability and may be applied
to assess the large-scale distribution of other rare or elusive mammalian carnivores. 相似文献
232.
Chávez-Sánchez María-Cristina Abad-Rosales Selene Lozano-Olvera Rodolfo Montoya-Rodríguez Leobardo Franco-Nava Miguel Ángel Mejía-Ruíz Claudio Humberto Pestryakov Alexey Bogdanchikova Nina 《Environmental science and pollution research international》2021,28(7):8224-8234
Environmental Science and Pollution Research - The objective of this study was to evaluate the histopathological alterations in juvenile Penaeus vannamei caused by silver nanoparticles (AgNPs) for... 相似文献
233.
234.
Manuel R. Guariguata Jonathan P. Cornelius Bruno Locatelli Claudio Forner G. Arturo Sánchez-Azofeifa 《Mitigation and Adaptation Strategies for Global Change》2008,13(8):793-808
The relationship between tropical forests and global climate change has so far focused on mitigation, while much less emphasis
has been placed on how management activities may help forest ecosystems adapt to this change. This paper discusses how tropical
forestry practices can contribute to maintaining or enhancing the adaptive capacity of natural and planted forests to global
climate change and considers challenges and opportunities for the integration of tropical forest management in broader climate
change adaptation. In addition to the use of reduced impact logging to maintain ecosystem integrity, other approaches may
be needed, such as fire prevention and management, as well as specific silvicultural options aimed at facilitating genetic
adaptation. In the case of planted forests, the normally higher intensity of management (with respect to natural forest) offers
additional opportunities for implementing adaptation measures, at both industrial and smallholder levels. Although the integration
in forest management of measures aimed at enhancing adaptation to climate change may not involve substantial additional effort
with respect to current practice, little action appears to have been taken to date. Tropical foresters and forest-dependent
communities appear not to appreciate the risks posed by climate change and, for those who are aware of them, practical guidance
on how to respond is largely non-existent. The extent to which forestry research and national policies will promote and adopt
management practices in order to assist production forests adapt to climate change is currently uncertain. Mainstreaming adaptation
into national development and planning programs may represent an initial step towards the incorporation of climate change
considerations into tropical forestry. 相似文献
235.
Amine-Khodja A Trubetskaya O Trubetskoj O Cavani L Ciavatta C Guyot G Richard C 《Chemosphere》2006,62(6):1021-1027
Humic-like substances (HLS) were extracted from a mixture of sewage sludges and trimmings (70-30%, w/w) after different times of composting (0, 70 days and 130 days). HLS were analyzed by elemental analysis, UV-visible and fluorescence spectroscopy and also tested for their ability to photosensitize the degradation of Irgarol. The rate of Irgarol photodegradation in artificial solar light was found to be 2.5- to 4.3-fold higher in the presence of HLS than in buffered Milli-Q water. These results were confirmed by experiments in solar light that evidenced the photodegrading properties of HLS in a more striking way. Using 2-propanol as hydroxyl radical scavenger, we could show that hydroxyl radicals contributed to the photosensitized Irgarol degradation for about 25%. The photodegrading activity of HLS, their absorbance and their emissive properties were all found to increase between 0 and 70 days of composting and to remain quite constant between 70 and 130 days. The degree of humification varied in the same way, linking all these properties to the humification process. 相似文献
236.
Graciela A. Canziani Rosana M. Ferrati Claudio Rossi Diego Ruiz-Moreno 《Regional Environmental Change》2006,6(4):181-191
The purpose of this work is to assess the impact on the Esteros del Ibera wetland ecosystem caused by the Yacyreta dam, a large hydroelectric power plant on the Parana River, Argentina, in comparison to other factors of environmental change. The project of the dam started around 1970. The power plant began operating in 1994. In 1989, the neighboring Ibera wetland ecosystem showed a substantial increase in the water level for which several different causes were conceivable, including climate change and the dam construction. We analyzed all existing hydrometeorological data and studied other changes that were observed in this ecosystem. A water balance model was used to analyze different scenarios. Increased groundwater inflow, generated since the construction of the dam, appears to be affecting the wetland more than any other factor. The study has implications for the assessment of global and regional consequences of building dams.
相似文献
Graciela A. CanzianiEmail: Phone: +54-2292-447104Fax: +54-2293-446317 |