全文获取类型
收费全文 | 489篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 27篇 |
废物处理 | 13篇 |
环保管理 | 90篇 |
综合类 | 92篇 |
基础理论 | 119篇 |
环境理论 | 2篇 |
污染及防治 | 99篇 |
评价与监测 | 39篇 |
社会与环境 | 13篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 5篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 9篇 |
2019年 | 10篇 |
2018年 | 17篇 |
2017年 | 12篇 |
2016年 | 15篇 |
2015年 | 14篇 |
2014年 | 18篇 |
2013年 | 32篇 |
2012年 | 21篇 |
2011年 | 32篇 |
2010年 | 27篇 |
2009年 | 30篇 |
2008年 | 29篇 |
2007年 | 28篇 |
2006年 | 28篇 |
2005年 | 23篇 |
2004年 | 18篇 |
2003年 | 12篇 |
2002年 | 15篇 |
2001年 | 11篇 |
2000年 | 12篇 |
1999年 | 8篇 |
1998年 | 12篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1958年 | 1篇 |
1943年 | 1篇 |
排序方式: 共有499条查询结果,搜索用时 15 毫秒
151.
Non-invasive prenatal testing has been in clinical use for a decade; however, there is evidence that this technology will be more widely applied within the next few years. Guidance is therefore required to ensure that the procedure is offered in a way that is evidence based and ethically and clinically acceptable. We conducted a systematic review of the current relevant literature to ascertain the factors that should be considered when offering non-invasive prenatal testing in a clinical setting. We undertook a systematic search of relevant databases, journals and reference lists, and from an initial list of 298 potential papers, identified 11 that were directly relevant to the study. Original data were extracted and presented in a table, and the content of all papers was analysed and presented in narrative form. Four main themes emerged: perceived attributes of the test, regulation and ethical issues, non-invasive prenatal testing in practice and economic considerations. However, there was a basic difference in the approach of actual or potential service users, who were very positive about the benefits of the technology, compared with other research participants, who were concerned with the potential moral and ethical outcomes of using this testing method. Recommendations for the appropriate use of non-invasive prenatal testing are made. © 2013 John Wiley & Sons, Ltd. 相似文献
152.
153.
Pimp Your Landscape: A Tool for Qualitative Evaluation of the Effects of Regional Planning Measures on Ecosystem Services 总被引:1,自引:0,他引:1
The article presents the platform “Pimp your landscape” (PYL), which aims firstly at the support of planners by simulating
alternative land-use scenarios and by an evaluation of benefits or risks for regionally important ecosystem services. Second,
PYL supports an integration of information on environmental and landscape conditions into impact assessment. Third, PYL supports
the integration of impacts of planning measures on ecosystem services. PYL is a modified 2-D cellular automaton with GIS features.
The cells have the major attribute “land-use type” and can be supplemented with additional information, such as specifics
regarding geology, topography and climate. The GIS features support the delineation of non-cellular infrastructural elements,
such as roads or water bodies. An evaluation matrix represents the core element of the system. In this matrix, values in a
relative scale from 0 (lowest value) to 100 (highest value) are assigned to the land-use types and infrastructural elements
depending on their effect on ecosystem services. The option to configure rules for describing the impact of environmental
attributes and proximity effects on cell values and land-use transition probabilities is of particular importance. User interface
and usage of the platform are demonstrated by an application case. Constraints and limits of the recent version are discussed,
including the need to consider in the evaluation, landscape-structure aspects such as patch size, fragmentation and spatial
connectivity. Regarding the further development, it is planned to include the impact of land management practices to support
climate change adaptation and mitigation strategies in regional planning. 相似文献
154.
Torbjørn M. Johnsen Wenche Eikrem Christine D. Olseng Knut E. Tollefsen Vilhelm Bjerknes 《Journal of the American Water Resources Association》2010,46(1):6-13
Johnsen, Torbjørn M., Wenche Eikrem, Christine D. Olseng, Knut E. Tollefsen, and Vilhelm Bjerknes, 2010. Prymnesium parvum: The Norwegian Experience. Journal of the American Water Resources Association (JAWRA) 46(1):6-13. DOI: 10.1111/j.1752-1688.2009.00386.x Abstract: In Norwegian waters, Prymnesium parvum has been reported from Oslofjorden in the south to Spitzbergen in the north. However, blooms of P. parvum have only been reported from the Sandsfjorden system in Ryfylke, Western Norway where the salinity of the permanent brackish layer (2-5 m) typically is in the range of 4-7 psu during the summer months. The first bloom on record occurred in 1989, and it killed 750 metric tons of caged salmon and trout which was a significant economic loss to the fish farming industry. Toxic blooms occurred as well in subsequent years and the number of fish farms in the area decreased considerably as did the occurrence of P. parvum. In 2005, fish farming was reintroduced to the area and again, in 2007 a toxic bloom of P. parvum killed 135 metric tons of caged fish. The Norwegian Institute for Water Research has, in collaboration with “Erfjord Stamfisk” fish farm, set up a monitoring program that includes light microscopy cell counts of Prymnesium, water quality measurements, and observation of the caged fish. A submergible fish net was mounted over the fish pens and during the toxic outbreak of P. parvum in July-August 2007, which was as previous years confined to the upper brackish water layer, the fish nets were lowered to 10 m depths below the surface and fish feeding was temporarily stopped. Despite substantial weight loss, the fish survived the toxic bloom and the economic loss was minimal. Monitoring of P. parvum bloom dynamics in 2007 revealed that populations were initially dominated by the nonmotile forms which were gradually replaced by the flagellated forms. Toxicity was observed when the flagellated cells dominated populations in the summer. Chrysochromulina, solitary small Chaetoceros species, and small centric diatoms co-existed with P. parvum during the monitoring period (June-October). 相似文献
155.
Ingrid Christine Koch Coleen Vogel Zarina Patel 《Mitigation and Adaptation Strategies for Global Change》2007,12(8):1323-1339
Climate change is a multi-dimensional issue and in terms of adaptation numerous state and non-state actors are involved from
global to national and local scales. The aim of this paper is first to analyse specific institutional networks involved in
climate change predominantly at the national level in South Africa and second to determine how different stakeholders perceive
their role vis-a-vis climate change adaptation. Within the South African context there is a gap in understanding and evaluating
how institutional networks operate and thus the findings of this work may help inform and strengthen such relationships in
the future. Results showed that few institutions fully understand the implications of adaptation and their roles and responsibilities
have not yet been properly defined. Constraints relating to capacity, lack of awareness and poor information flow need to
be addressed. Climate change is perceived as an important issue although problems such as poverty reduction and job creation
remain national priorities. Most importantly this research has demonstrated how adaptation challenges the hierarchical manner
in which government works and a more collaborative approach to climate change adaptation is needed. Adaptation needs to be
mainstreamed and institutional networks need to be strengthened in order for adaptation mechanisms to be effectively implemented.
相似文献
Ingrid Christine KochEmail: |
156.
157.
158.
159.
Pengbo Liu Yu-Wen Chien Efstathia Papafragkou Hui-Mien Hsiao Lee-Ann Jaykus Christine Moe 《Food and environmental virology》2009,1(3-4):141-147
The human noroviruses (NoV) are the major cause of acute non-bacterial gastroenteritis and are commonly transmitted by foodborne routes. Epidemiological evidence from propagated outbreaks, as well as environmental sampling, suggest that these viruses are environmentally stable. The purpose of this study was to examine the persistence of representative human NoV on the fingertips of volunteers and on commonly used food preparation surfaces. Human fingerpads and surfaces (stainless steel, Formica®, and ceramic) were inoculated with 20% fecal suspensions of Norwalk virus (NV) or Snow Mountain virus (SMV). The virus inocula were recovered by elution at serial time points ranging from 0 to 120 min post-inoculation (for fingerpads) and after up to 42 days (for surfaces). The quantity of detectable viral RNA, expressed as genome equivalent particles (GEP) was evaluated using quantitative real-time RT-PCR (RT-qPCR). The amount of NV RNA on the surface decreased gradually over time, with an average reduction ranging from 1.5 to 2.9 log10 GEP after 21–28 days storage under ambient conditions. SMV showed greater environmental persistence, with a 0.4–1.2 log10 GEP reduction on all three surfaces after 42 days of ambient storage. On fingerpads, the amount of human NoV RNA declined slightly (<0.25 log10) after 15 min and remained relatively unchanged thereafter (through 120 min). These results support the epidemiological evidence that food preparation surfaces and human hands can act as vehicles for human NoV transmission long after the initial contamination event has occurred. 相似文献