全文获取类型
收费全文 | 654篇 |
免费 | 33篇 |
国内免费 | 10篇 |
专业分类
安全科学 | 43篇 |
废物处理 | 24篇 |
环保管理 | 147篇 |
综合类 | 81篇 |
基础理论 | 216篇 |
环境理论 | 1篇 |
污染及防治 | 113篇 |
评价与监测 | 33篇 |
社会与环境 | 24篇 |
灾害及防治 | 15篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 6篇 |
2021年 | 11篇 |
2020年 | 17篇 |
2019年 | 17篇 |
2018年 | 27篇 |
2017年 | 25篇 |
2016年 | 33篇 |
2015年 | 23篇 |
2014年 | 33篇 |
2013年 | 56篇 |
2012年 | 37篇 |
2011年 | 59篇 |
2010年 | 32篇 |
2009年 | 32篇 |
2008年 | 45篇 |
2007年 | 40篇 |
2006年 | 32篇 |
2005年 | 27篇 |
2004年 | 16篇 |
2003年 | 14篇 |
2002年 | 31篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有697条查询结果,搜索用时 15 毫秒
71.
In August 2005, after the devastating tsunami in the Indian Ocean Basin, a Memorandum of Understanding (MoU) for the cessation of hostilities was signed by Aceh's longstanding adversaries—the Government of Indonesia and the Free Aceh Movement (GAM). The tsunami was a major catalyst for ‘disaster diplomacy’—international political pressure, which, this paper argues, was an important ingredient in creating conditions for the MoU, although the situation within Aceh also shaped the peace process. Based on interviews conducted in 2006 and 2007 with government officials, GAM representatives and fighters, and non‐governmental organization staff in Aceh, this paper finds that assistance for tsunami survivors far exceeds that available for conflict survivors and ex‐combatants. The formation of these two solitudes—the tsunami‐affected and the conflict‐affected—compounds challenges for sustaining peace in Aceh. This research points to an enduring lack of livelihoods for former fighters and conflict victims that may threaten a sustainable peace. 相似文献
72.
Ashley A. Weaver Jennifer W. Talton Ryan T. Barnard Samantha L. Schoell Katrina R. Swett Joel D. Stitzel 《Traffic injury prevention》2015,16(4):S108-S116
Objective: Injury risk curves estimate motor vehicle crash (MVC) occupant injury risk from vehicle, crash, and/or occupant factors. Many vehicles are equipped with event data recorders (EDRs) that collect data including the crash speed and restraint status during a MVC. This study's goal was to use regulation-required data elements for EDRs to compute occupant injury risk for (1) specific injuries and (2) specific body regions in frontal MVCs from weighted NASS-CDS data.Methods: Logistic regression analysis of NASS-CDS single-impact frontal MVCs involving front seat occupants with frontal airbag deployment was used to produce 23 risk curves for specific injuries and 17 risk curves for Abbreviated Injury Scale (AIS) 2+ to 5+ body region injuries. Risk curves were produced for the following body regions: head and thorax (AIS 2+, 3+, 4+, 5+), face (AIS 2+), abdomen, spine, upper extremity, and lower extremity (AIS 2+, 3+). Injury risk with 95% confidence intervals was estimated for 15–105 km/h longitudinal delta-Vs and belt status was adjusted for as a covariate.Results: Overall, belted occupants had lower estimated risks compared to unbelted occupants and the risk of injury increased as longitudinal delta-V increased. Belt status was a significant predictor for 13 specific injuries and all body region injuries with the exception of AIS 2+ and 3+ spine injuries. Specific injuries and body region injuries that occurred more frequently in NASS-CDS also tended to carry higher risks when evaluated at a 56 km/h longitudinal delta-V. In the belted population, injury risks that ranked in the top 33% included 4 upper extremity fractures (ulna, radius, clavicle, carpus/metacarpus), 2 lower extremity fractures (fibula, metatarsal/tarsal), and a knee sprain (2.4–4.6% risk). Unbelted injury risks ranked in the top 33% included 4 lower extremity fractures (femur, fibula, metatarsal/tarsal, patella), 2 head injuries with less than one hour or unspecified prior unconsciousness, and a lung contusion (4.6–9.9% risk). The 6 body region curves with the highest risks were for AIS 2+ lower extremity, upper extremity, thorax, and head injury and AIS 3+ lower extremity and thorax injury (15.9–43.8% risk).Conclusions: These injury risk curves can be implemented into advanced automatic crash notification (AACN) algorithms that utilize vehicle EDR measurements to predict occupant injury immediately following a MVC. Through integration with AACN, these injury risk curves can provide emergency medical services (EMS) and other patient care providers with information on suspected occupant injuries to improve injury detection and patient triage. 相似文献
73.
74.
This paper examines the relationship between the development of the dominant industrial food system and its associated global economic drivers and the environmental sustainability of agricultural landscapes. It makes the case that the growth of the global industrial food system has encouraged increasingly complex forms of “distance” that separate food both geographically and mentally from the landscapes on which it was produced. This separation between food and its originating landscape poses challenges for the ability of more localized agricultural sustainability initiatives to address some of the broader problems in the global food system. In particular, distance enables certain powerful actors to externalize ecological and social costs, which in turn makes it difficult to link specific global actors to particular biophysical and social impacts felt on local agricultural landscapes. Feedback mechanisms that normally would provide pressure for improved agricultural sustainability are weak because there is a lack of clarity regarding responsibility for outcomes. The paper provides a brief illustration of these dynamics with a closer look at increased financialization in the food system. It shows that new forms of distancing are encouraged by the growing significance of financial markets in global agrifood value chains. This dynamic has a substantial impact on food system outcomes and ultimately complicates efforts to scale up small-scale local agricultural models that are more sustainable. 相似文献
75.
Robert A. Rose Dirck Byler J. Ron Eastman Erica Fleishman Gary Geller Scott Goetz Liane Guild Healy Hamilton Matt Hansen Rachel Headley Jennifer Hewson Ned Horning Beth A. Kaplin Nadine Laporte Allison Leidner Peter Leimgruber Jeffrey Morisette John Musinsky Lilian Pintea Ana Prados Volker C. Radeloff Mary Rowen Sassan Saatchi Steve Schill Karyn Tabor Woody Turner Anthony Vodacek James Vogelmann Martin Wegmann David Wilkie Cara Wilson 《Conservation biology》2015,29(2):350-359
In an effort to increase conservation effectiveness through the use of Earth observation technologies, a group of remote sensing scientists affiliated with government and academic institutions and conservation organizations identified 10 questions in conservation for which the potential to be answered would be greatly increased by use of remotely sensed data and analyses of those data. Our goals were to increase conservation practitioners’ use of remote sensing to support their work, increase collaboration between the conservation science and remote sensing communities, identify and develop new and innovative uses of remote sensing for advancing conservation science, provide guidance to space agencies on how future satellite missions can support conservation science, and generate support from the public and private sector in the use of remote sensing data to address the 10 conservation questions. We identified a broad initial list of questions on the basis of an email chain‐referral survey. We then used a workshop‐based iterative and collaborative approach to whittle the list down to these final questions (which represent 10 major themes in conservation): How can global Earth observation data be used to model species distributions and abundances? How can remote sensing improve the understanding of animal movements? How can remotely sensed ecosystem variables be used to understand, monitor, and predict ecosystem response and resilience to multiple stressors? How can remote sensing be used to monitor the effects of climate on ecosystems? How can near real‐time ecosystem monitoring catalyze threat reduction, governance and regulation compliance, and resource management decisions? How can remote sensing inform configuration of protected area networks at spatial extents relevant to populations of target species and ecosystem services? How can remote sensing‐derived products be used to value and monitor changes in ecosystem services? How can remote sensing be used to monitor and evaluate the effectiveness of conservation efforts? How does the expansion and intensification of agriculture and aquaculture alter ecosystems and the services they provide? How can remote sensing be used to determine the degree to which ecosystems are being disturbed or degraded and the effects of these changes on species and ecosystem functions? 相似文献
76.
Current political conditions, primarily budgetary uncertainty, and the related reluctance to make funding commitments for
future generations, have raised questions about the costs of conservation and environmental protection that have not previously
been asked. As Federal investments are scrutinized and budgets become ever more constrained, the costs associated with environmental
requirements could begin to be of greater importance and to influence decisions on Federal projects. In response to concerns
about the U.S. Army Corps of Engineers (Corps) spending under the Endangered Species Act (P.L. 93-205) (ESA), a limited investigation
was performed to determine the accuracy of reported Corps expenditures. The investigation showed that, for particular groups
of species, actual conservation costs for threatened and endangered species may be twice the amounts previously reported in
the annual ESA expenditure reporting to the U.S. Fish and Wildlife Service. In light of this finding, the Corps has sought
a means to provide more accurate and consistent reporting of expenditures for addressing threatened and endangered species.
A Species Costs Template (template) has been developed to identify the types and magnitude of costs related to the ESA and
to counteract the impediments (legal, institutional, and practical) to underreporting costs. The template will be used by
the Corps for reporting ESA costs beginning with Fiscal Year 2005 (FY05) (reported in January 2006). Five broad categories
of expenditures (effects determination costs, ESA protection and conservation costs, equipment costs, opportunity costs, and
other species costs) are identified by the template. 相似文献
77.
78.
Based on actual project experiences over the past decade, execution strategies for remediation projects have varied significantly. For example, the overlap between the assessment and cleanup phases can range from none (for projects that complete assessment activities before starting the cleanup) to almost half of the assessment duration (for projects that may be under pressure to show progress at the site). This article quantifies the relationship between remediation project execution strategies, project definition components, and remediation project cost and schedule performance. By relating project outcomes to indicators that can be monitored early in the project cycle, project teams may be able to correct problems before they affect the ultimate performance of the remediation project. 相似文献
79.
This report was by John F. Disinger, Professor of Natural Resources, and Jennifer L. Tomsen, Graduate Teaching Associate in Natural Resources, The Ohio State University, Columbus, Ohio, 43210–1085, USA. 相似文献
80.
Jennifer K. Schultz Richard L. Pyle Edward DeMartini Brian W. Bowen 《Marine Biology》2007,151(1):167-175
Color variation is used in taxonomic classification of reef fishes, but it may not reliably indicate evolutionary divergence.
In the central Pacific, there are three color morphs of the flame angelfish, Centropyge loriculus: a red morph that occurs primarily in the Hawaiian archipelago, the endemic Marquesan color morph with reduced black markings,
and an orange morph that occurs throughout the rest of Oceania. The red and orange morphs co-occur at Johnston Atoll (1,300 km
south of Hawai’i), but intermediate forms have not been reported. To determine whether the three color morphs represent distinct
evolutionary lineages, we compared 641 base pairs of mitochondrial cytochrome b. Forty-one closely related haplotypes were observed in 116 individuals. Analysis of molecular variance (AMOVA) indicated
no significant genetic structure among color morphs (ΦST = 0.011, P = 0.147). Likewise, there was no significant pairwise structure between sampling locations, separated by up to 5,700 km,
after a Bonferroni correction (ΦST = 0.000–0.080, P = 0.0130–0.999). Genetic studies in conjunction with larval distribution data indicate that Centropyge species are highly dispersive. While there is a strong geographic component to the distribution of color morphs in C. loriculus, we find no evidence for corresponding genetic partitioning. We do not rule out an adaptive role for color differentiation,
but our data do not support emerging species. 相似文献