全文获取类型
收费全文 | 1115篇 |
免费 | 18篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 39篇 |
废物处理 | 43篇 |
环保管理 | 140篇 |
综合类 | 230篇 |
基础理论 | 235篇 |
环境理论 | 3篇 |
污染及防治 | 324篇 |
评价与监测 | 70篇 |
社会与环境 | 53篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 11篇 |
2022年 | 16篇 |
2021年 | 23篇 |
2020年 | 16篇 |
2019年 | 15篇 |
2018年 | 39篇 |
2017年 | 40篇 |
2016年 | 44篇 |
2015年 | 36篇 |
2014年 | 42篇 |
2013年 | 61篇 |
2012年 | 49篇 |
2011年 | 78篇 |
2010年 | 59篇 |
2009年 | 61篇 |
2008年 | 71篇 |
2007年 | 69篇 |
2006年 | 38篇 |
2005年 | 55篇 |
2004年 | 30篇 |
2003年 | 36篇 |
2002年 | 34篇 |
2001年 | 19篇 |
2000年 | 15篇 |
1999年 | 10篇 |
1998年 | 16篇 |
1997年 | 5篇 |
1996年 | 11篇 |
1995年 | 19篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 12篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1969年 | 2篇 |
1963年 | 2篇 |
1961年 | 2篇 |
1959年 | 3篇 |
1958年 | 3篇 |
1957年 | 2篇 |
排序方式: 共有1140条查询结果,搜索用时 437 毫秒
121.
This paper presents an agent-based approach for error detection in incident management organizations. The approach consists of several parts. First, a formal approach for the specification and hierarchical verification of both traces and properties. Incomplete traces are enriched by enrichment rules. Furthermore, a classification mechanism is presented for the different properties in incident management that is based on psychological literature. Classification of errors provides insight in the functioning of the agents involved with respect to their roles. This insight enables the provision of dedicated training sessions and allows software support to give appropriate warning messages during incident management. 相似文献
122.
There must be a change in attitude towards end-of-life products. The view that these products pose a liability must be changed. Secondary material is valuable as raw material. Thus, activities encouraging changes in opinion are important.Two major EU directives guide the recycling process; the Directive of End-of-Life Vehicles (ELV) and the Directive of Waste Electrical and Electronic Equipment (WEEE). Both focus on the input of the recycling system, not on what is coming out of the system.The WEEE Directive is the legislation on the European level that governs the handling and processing of these types of products. The WEEE Directive is not only aimed at stricter handling and reduction of hazardous materials but also encourages EU member states to support technical development in order to facilitate increased recycling.In order to properly address these issues a mind-set, material hygiene, has been introduced. The basic idea is to act, in every life cycle phase of the product, towards highest possible efficiency in recycling. The outcome of useful material is in focus.A study on dishwashers is made with copper outcome as target. The results are based on Swedish conditions but general conclusions can be made. Limited design efforts can raise the outcome of valuable materials, if the recycling process is organized in an optimal manner.A theoretical concept of disassembly structures is used to draw general conclusions on the case study.Increasing product recycling suitability is one side of the problem; another is increasing effectiveness of handling and processing of end-of-life products.The purpose of this paper is to introduce the concept of “material hygiene” and based on that demonstrate a method for grading structural properties in a recycling perspective. The findings presented in this paper are based on a field study in which a number of dishwashers were disassembled and analyzed. 相似文献
123.
124.
125.
E. Joanne Verweij Martine C. de Vries Esther J. Oldekamp Alex J. Eggink Dick Oepkes Femke Slaghekke Jochem K. H. Spoor Jan A. Deprest Jena L. Miller Ahmet A. Baschat Philip L. J. DeKoninck 《黑龙江环境通报》2021,41(8):949-956
Since the completion of the Management of Myelomeningocoele Study, maternal-fetal surgery for spina bifida has become a valid option for expecting parents. More recently, multiple groups are exploring a minimally invasive approach and recent outcomes have addressed many of the initial concerns with this approach. Based on a previously published framework, we attempt to delineate the developmental stage of the surgical techniques. Furthermore, we discuss the barriers of performing randomized controlled trials comparing two surgical interventions and suggest that data collection through registries is an alternative method to gather high-grade evidence. 相似文献
126.
127.
Guus J.M. Velders Jan Matthijsen 《Atmospheric environment (Oxford, England : 1994)》2009,43(25):3858-3866
The extent of the exceedance of the EU limit values for nitrogen dioxide (NO2) and particulate matter (PM10) concentrations within the Netherlands is expected to decrease significantly, in the coming years. Whether limit values will actually be exceeded, in the next decade, depends not only on European, national and local policies, but also on the effects of inevitable interannual meteorological fluctuations. An analysis of model calculations and measurements yields variations (1 sigma) in the annual average concentration of about 5% for NO2 and 9% for PM10, due to meteorological fluctuations. These deviations from long-term average concentrations affect assessments of future levels, set against limit values. For instance, an NO2 concentration of 39 μg m?3, estimated for a given year with long-term average meteorology, indicates that it is likely (chance >66%) that the limit value of 40 μg m?3 will not be exceeded in that particular year. At the same time, the estimation also indicates, for example, that this situation is unlikely (change <33%) to continue for three years in a row. However, with an estimated concentration of 38 μg m?3, it is likely that the limit value will not be exceeded for three years in a row. The limit value for the daily average PM10 concentration is equivalent to an annual average of about 32 μg m?3. This threshold is unlikely to be exceeded for three years in a row, when an annual average concentration of 29 μg m?3 is estimated. Interannual variations in concentrations of NO2 and PM10 are linked to large-scale meteorological fluctuations. Therefore, similar results can be expected for other European countries. 相似文献
128.
Rosalind Pratt Jan Deprest Tom Vercauteren Sebastien Ourselin Anna L. David 《黑龙江环境通报》2015,35(12):1159-1166
Fetal surgery has become a clinical reality, with interventions for twin-to-twin transfusion syndrome (TTTS) and spina bifida demonstrated to improve outcome. Fetal imaging is evolving, with the use of 3D ultrasound and fetal MRI becoming more common in clinical practise. Medical imaging analysis is also changing, with technology being developed to assist surgeons by creating 3D virtual models that improve understanding of complex anatomy, and prove powerful tools in surgical planning and intraoperative guidance. We introduce the concept of computer-assisted surgical planning, and present the results of a systematic review of image reconstruction for fetal surgical planning that identified six articles using such technology. Indications from other specialities suggest a benefit of surgical planning and guidance to improve outcomes. There is therefore an urgent need to develop fetal-specific technology in order to improve fetal surgical outcome. © 2015 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd. 相似文献
129.
130.
The transition in Dutch water management 总被引:2,自引:1,他引:1
Over the past decades, the Dutch people have been confronted with severe water-related problems, which are the result of an unsustainable water system, arising from human interventions in the physical infrastructure of the water system and the water management style. The claims of housing, industry, infrastructure and agriculture have resulted in increasing pressure on the water system. The continuous subsidence of soil and climate change has put pressure on the land. Hence, the nature and magnitude of water-related problems have changed. Longitudinal research of relevant national policy documents reveals that the water management regime has changed its water management style over the past 30 years from a technocratic scientific style towards an integral and participatory style. We have investigated if the historical development in Dutch Water management can be characterized as a transition. Based on longitudinal research through an integrated systems analysis, document research and expert interviews, we have reconstructed the historical narrative by using the transition concepts of multi-level and multi-phase. This research indicates that the shift in Dutch Water management can be characterized as a transition. This transition is currently in the take-off stage and near the acceleration stage. This is a crucial stage as long as the considerable gap between the strategic macro-vision and the practical implementation at the micro-level remains. As long as these levels are not compatible (modulation), the transition will not be completed successfully. Transition management as multi-level governance model should therefore be adopted to facilitate the modulation. 相似文献