全文获取类型
收费全文 | 414篇 |
免费 | 11篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 15篇 |
废物处理 | 14篇 |
环保管理 | 124篇 |
综合类 | 26篇 |
基础理论 | 124篇 |
环境理论 | 1篇 |
污染及防治 | 82篇 |
评价与监测 | 23篇 |
社会与环境 | 18篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 18篇 |
2015年 | 9篇 |
2014年 | 12篇 |
2013年 | 40篇 |
2012年 | 21篇 |
2011年 | 25篇 |
2010年 | 16篇 |
2009年 | 14篇 |
2008年 | 18篇 |
2007年 | 14篇 |
2006年 | 20篇 |
2005年 | 20篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 14篇 |
2001年 | 12篇 |
2000年 | 12篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 9篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1932年 | 1篇 |
排序方式: 共有430条查询结果,搜索用时 15 毫秒
31.
32.
33.
Nina Rønsted Seana K. Walsh Margaret Clark Merlin Edmonds Tim Flynn Scott Heintzman Alexander Loomis David Lorence Uma Nagendra Ben Nyberg Michael Opgenorth Lauren Weisenberger Adam Williams Dustin Wolkis Kenneth R. Wood Matthew Keir 《Conservation biology》2022,36(4):e13896
The International Union for Conservation of Nature's Red List of Threatened Species (IUCN Red List) is the world's most comprehensive information source on the global conservation status of species. Governmental agencies and conservation organizations increasingly rely on IUCN Red List assessments to develop conservation policies and priorities. Funding agencies use the assessments as evaluation criteria, and researchers use meta-analysis of red-list data to address fundamental and applied conservation science questions. However, the circa 143,000 IUCN assessments represent a fraction of the world's biodiversity and are biased in regional and organismal coverage. These biases may affect conservation priorities, funding, and uses of these data to understand global patterns. Isolated oceanic islands are characterized by high endemicity, but the unique biodiversity of many islands is experiencing high extinction rates. The archipelago of Hawaii has one of the highest levels of endemism of any floristic region; 90% of its 1367 native vascular plant taxa are classified as endemic. We used the IUCN's assessment of the complete single-island endemic (SIE) vascular plant flora of Kauai, Hawaii, to assess the proportion and drivers of decline of threatened plants in an oceanic island setting. We compared the IUCN assessments with federal, state, and other local assessments of Kauai species or taxa of conservation concern. Finally, we conducted a preliminary assessment for all 1044 native vascular plants of Hawaii based on IUCN criterion B by estimating area of occupancy, extent of occurrence, and number of locations to determine whether the pattern found for the SIE vascular flora of Kauai is comparable to the native vascular flora of the Hawaiian Islands. We compared our results with patterns observed for assessments of other floras. According to IUCN, 256 SIE vascular plant taxa are threatened with extinction and 5% are already extinct. This is the highest extinction risk reported for any flora to date. The preliminary assessment of the native vascular flora of Hawaii showed that 72% (753 taxa) is threatened. The flora of Hawaii may be one of the world's most threatened; thus, increased and novel conservation measures in the state and on other remote oceanic islands are urgently needed. 相似文献
34.
We used strontium isotopes and analysis of foliar and soil nutrients to test whether erosion can rejuvenate the supply of rock-derived nutrients in the lowland tropical rain forest of La Selva, Costa Rica. We expected that these nutrients would be depleted from soils on stable surfaces, a result of over one million years of weathering in situ. In fact, trees and palms in all landscape positions derive a relatively high percentage (> or =40%) of their strontium from bedrock, rather than atmospheric, sources. The fraction that is rock-derived increases on slopes, but with no detectable effect on plant macronutrient concentrations. These results differ from those in a similar ecosystem on Kauai, Hawaii, where plants on uneroded surfaces derive almost all of their foliar Sr from atmospheric, rather than bedrock, sources. The results from La Selva challenge the assumption that tropical Oxisols in general have low nutrient inputs from bedrock, and support the hypothesis that erosion can increase the supply of these nutrients in lower landscape positions. 相似文献
35.
Ibáñez I Clark JS Dietze MC Feeley K Hersh M LaDeau S McBride A Welch NE Wolosin MS 《Ecology》2006,87(8):1896-1906
Efforts to anticipate threats to biodiversity take the form of species richness predictions (SRPs) based on simple correlations with current climate and habitat area. We review the major approaches that have been used for SRP, species-area curves and climate envelopes, and suggest that alternative research efforts may provide more understanding and guidance for management. Extinction prediction suffers from a number of limitations related to data and the novelty of future environments. We suggest additional attention to (1) identification of variables related to biodiversity that are diagnostic and potentially more predictable than extinction, (2) constraints on species dispersal and reproduction that will determine population persistence and range shifts, including limited sources or potential immigrants for many regions, and (3) changes in biotic interactions and phenology. We suggest combinations of observational and experimental approaches within a framework available for ingesting heterogeneous data sources. Together, these recommendations amount to a shift in emphasis from prediction of extinction numbers to identification of vulnerabilities and leading indicators of change, as well as suggestions for surveillance tools needed to evaluate important variables and the experiments likely to provide most insight. 相似文献
36.
BFR burdens in abiotic media have been less studied than in biota, despite their essential value as an aide to identifying sources, temporal and geographic trends and exposure routes. Many polymer products consist of several percent by weight of BFRs. Global trade in these can result in rapid and wholesale BFR movement. Loss from in-use products of nonreactive BFRs may be important, particularly in respect to indoor exposure. In the case of BDE-209, discharges from publicly owned treatment works may be substantial. BFR burdens in air, water and sewage sludge respond rapidly to changes in environmental BFR inputs. PBDEs have been the most widely studied. In many locales PBDE burdens in these media now surpass those of PCBs. Air and water near sources and urban areas are typically enriched relative to rural locales. The more volatile PBDEs dominate in the vapor phase, while BDE-209 typically predominates on particulates. Evidence exists for long-range transport of the more volatile PBDEs. A greater diversity of BFRs (mostly PBDEs, HBCD and TBBP-A) has been detected in sewage sludges. Land application of these sludges on agricultural fields is one conduit for soil contamination. In general, environmental concentrations of BDE-209 appear to be increasing, while penta-BDE burdens in Europe may have peaked. Sediments function as longer-term integrators of environmental burdens. Concentrations of common BFRs therein may be substantial near point sources. Evidence for debromination in the environment has been limited to date. However, some laboratory and field observations suggest it is possible to a limited extent. 相似文献
37.
Lori L. Travis David E. Clark Amy E. Haskins Joseph A. Kilch 《Journal of Safety Research》2012,43(5-6):375-380
BackgroundMortality from traffic crashes is often higher in rural regions, and this may be attributable to decreased survival probability after severe injury.MethodsData were obtained from the National Automotive Sampling System – General Estimates System (NASS-GES) for 2002–2008. Using weighted survey logistic regression, three injury outcomes were analyzed: (a) Death overall, (b) Severe injury (incapacitating or fatal), and (c) Death, after severe injury. Models controlled for (pre-crash) person, event, and county level factors.ResultsThe sample included 883,473 motorists. Applying weights, this represented a population of 98,411,993. Only 2% of the weighted sample sustained a severe injury, and 9% of these severely injured motorists died. The probability of death overall and the probability of severe injury increased with older age, safety belt nonuse, vehicle damage, high speed, and early morning crashes . Males were less likely to be severely injured, but more likely to die if severely injured. Motorists in southern states were more likely to have severe injuries, but not more likely to die if severely injured. Motorists who crashed in very rural counties were significantly more likely to die overall, and were more likely to die if severely injured.ConclusionsMotorists with severe injury are more likely to die in rural areas, after controlling for person- and event-specific factors. 相似文献
38.
Jennifer Horney Matt Simon Shannon Grabich Philip Berke 《Journal of Environmental Planning and Management》2015,58(5):802-818
In accordance with the Disaster Mitigation Act, most US counties have a hazard mitigation plan (HMP) to reduce future disaster losses. HMPs are important as they can be used to proactively assess risk, direct future development, raise awareness and build consensus. Using a population-based sample, we interviewed residents of Bertie County, NC, about their awareness of and participation in the HMP process to determine if demographics, social vulnerability or hazard vulnerability were associated with increased awareness or participation. We also assessed whether these factors were associated with knowledge of policy changes and investments that were adopted in the HMP. Overall, the unemployed were the only group less likely to report awareness of or participation in HMP development. African-Americans, mobile home residents, the poor, short-term residents and those with less disaster experience were less likely to be aware of policies and investments prioritised in the HMP. Targeted efforts to increase awareness could potentially improve disaster outcomes among vulnerable populations. 相似文献
39.
Samples representing the damselfishes (Perciformes: Pomacentridae) Stegastes nigricans, Chrysiptera biocellata, C. glauca, and C. leucopoma from North Male Atoll, Republic of Maldives, and Guam, Southern Marianas, were surveyed electrophoretically. A sample representing C. leucopoma from Ngemelis Island, Republic of Palau, was included in the analysis to provide a within-Micronesia comparison. On average, products of 23 presumptive protein-coding loci were examined in each sample. In comparisons of Maldivian and Guamanian samples, absolute or virtually fixed allelic differences were detected at: (1) ADA
* and PEPS
* for Stegastes nigricans; (2) ADA
*, AAT-1
*, AAT-2
*, and mMDH
* for C. biocellata, and; (3) ADA
*, AAT-1
*, and AAT-2
* for C. glauca. At three polymorphic loci, ADA
*, sMDH-1
*, and sMDH-2
*, similar allele frequencies were found in Palauan and Guamanian samples representing C. leucopoma, suggesting that these samples share a gene pool. Significantly different allele frequencies at ADA
* and sMDH-1
* and a virtually fixed allelic difference at sMDH-2
* were detected between the Maldivian samples and each of the Micronesian samples representing C. leucopoma. The observed patterns of allele frequency differentiation suggest that Maldivian and Micronesian samples of each of the four study species represent separate demes. 相似文献
40.