全文获取类型
收费全文 | 278篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 12篇 |
废物处理 | 10篇 |
环保管理 | 23篇 |
综合类 | 53篇 |
基础理论 | 76篇 |
污染及防治 | 68篇 |
评价与监测 | 23篇 |
社会与环境 | 14篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 8篇 |
2016年 | 18篇 |
2015年 | 10篇 |
2014年 | 14篇 |
2013年 | 21篇 |
2012年 | 22篇 |
2011年 | 25篇 |
2010年 | 15篇 |
2009年 | 19篇 |
2008年 | 20篇 |
2007年 | 17篇 |
2006年 | 10篇 |
2005年 | 9篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1985年 | 2篇 |
1981年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有282条查询结果,搜索用时 46 毫秒
171.
Several extinct sperm whales (stem Physeteroidea) were recently proposed to differ markedly in their feeding ecology from the suction-feeding modern sperm whales Kogia and Physeter. Based on cranial, mandibular, and dental morphology, these Miocene forms were tentatively identified as macroraptorial feeders, able to consume proportionally large prey using their massive teeth and robust jaws. However, until now, no corroborating evidence for the use of teeth during predation was available. We report on a new specimen of the stem physeteroid Acrophyseter, from the late middle to early late Miocene of Peru, displaying unusual bony outgrowths along some of the upper alveoli. Considering their position and outer shape, these are identified as buccal maxillary exostoses. More developed along posterior teeth and in tight contact with the high portion of the dental root outside the bony alveoli, the exostoses are hypothesized to have developed during powerful bites; they may have worked as buttresses, strengthening the teeth when facing intense occlusal forces. These buccal exostoses further support a raptorial feeding technique for Acrophyseter and, indirectly, for other extinct sperm whales with a similar oral apparatus (Brygmophyseter, Livyatan, Zygophyseter). With a wide size range, these Miocene stem physeteroids were major marine macropredators, occupying ecological niches nowadays mostly taken by killer whales. 相似文献
172.
Julien Saada Olivier Parant Sylvie Kessler Jacqueline Aziza Marie France Sarramon 《黑龙江环境通报》2006,26(1):9-10
Congenital splenic cyst (CSC) is a rare condition, and only a few cases with prenatal diagnosis and no associated malformation have been reported. Spontaneous regression is possible in case of mild CSC (under 40 mm), but enlargement or secondary complications may lead to surgical treatment. We report, herein, two cases of isolated mild CSC with complete spontaneous postnatal regression. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
173.
174.
Lola Loussert Fabien Vidal Olivier Parant Safouane M. Hamdi Christophe Vayssiere Paul Guerby 《黑龙江环境通报》2020,40(5):519-527
For the past decades, growing attention has been given to aspirin use during pregnancy. It favors placentation by its proangiogenic, antithrombotic, and anti-inflammatory effects. Therefore, low doses of aspirin are prescribed in the prevention of placenta-mediated complications, mainly preeclampsia and fetal growth restriction. However, questions regarding its clinical application are still debated. Aspirin is effective in preventing preeclampsia in a high-risk population. Most guidelines recommend that risk stratification should rely on medical history. Nevertheless, screening performances dramatically improve if biochemical and biophysical markers are included. Concerning the appropriate timing and dose, latest studies suggest aspirin should be started before 16 weeks of pregnancy and at a daily dose of 100 mg or more. Further studies are needed to improve the identification of patients likely to benefit from prophylactic aspirin. Besides, the role of aspirin in the prevention of fetal growth restriction is still questioned. 相似文献
175.
176.
177.
An increasing number of organisations are moving towards assessing and reporting their environmental performance in a supply-chain context. Not only are such “footprint”-type assessments seen as more rigorous than sustainability reports created in-house, they also offer more abatement options than assessments limited to an organisation’s premises. Hybrid life-cycle assessment methods combining input-output analysis and process analysis are ideally suited to enumerate organisational footprints, because they were developed to enable overall complete results whilst being application-specific. We apply one of these hybrid methods, the Path Exchange Method to the task of planning for a sustainable campus at the University of Sydney in Australia. We show how this method can be used by an environmental or procurement officer for exploring environmental performance and abatement options across supply chains. We also show how parts of an organisation, for example University faculties, can be assessed and compared against each other. Whilst tools like ones used in this work enable quantitative decision support for procurement and operations policies, it takes staff awareness, engagement and training to successfully put such tools into practice. 相似文献
178.
179.
180.
Catharina J. E. Schulp Peter H. Verburg Peter J. Kuikman Gert-Jan Nabuurs Jos G. J. Olivier Wim de Vries Tom Veldkamp 《Environmental management》2013,51(3):709-723
National-scale inventories of soil organic carbon (SOC) and forest floor carbon (FFC) stocks have a high uncertainty. Inventories are often based on the interpolation of sampled information, often using a number of covariables to help such interpolation. The rationale for the choice of these covariables is not always documented, despite the fact that many local-scale studies have identified the factors explaining spatial variability of SOC and FFC stocks. These studies indicate, among others the importance of long-term land use history. Despite this, information on the effects of land use history has never been used to explain variability of carbon stocks in national-scale inventories. We designed an alternative method to improve national-scale inventories of SOC and FCC for the Dutch sand area that takes stock of the findings of detailed case studies. Determinants for SOC and FFC stocks derived from landscape-scale case studies were used to map national-scale spatial variability and to calculate national totals. The resulting national-scale spatial distribution was compared with the SOC stock map from the current Dutch greenhouse gas inventory. Using land use history to explain SOC variability decreased the error of the SOC stock estimate in 60 % of the area. The error in FFC stocks decreased in half of the forest area after including soil fertility, tree species, and forest age as explanatory factors. Estimates with reduced uncertainty will make land use and land management a more attractive and acceptable mitigation option to reduce emissions of greenhouse gases for the LULUCF sector. 相似文献