全文获取类型
收费全文 | 899篇 |
免费 | 3篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 38篇 |
废物处理 | 22篇 |
环保管理 | 269篇 |
综合类 | 68篇 |
基础理论 | 174篇 |
污染及防治 | 257篇 |
评价与监测 | 57篇 |
社会与环境 | 19篇 |
灾害及防治 | 4篇 |
出版年
2022年 | 7篇 |
2021年 | 5篇 |
2020年 | 8篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 17篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 114篇 |
2012年 | 21篇 |
2011年 | 43篇 |
2010年 | 32篇 |
2009年 | 27篇 |
2008年 | 46篇 |
2007年 | 41篇 |
2006年 | 47篇 |
2005年 | 27篇 |
2004年 | 39篇 |
2003年 | 32篇 |
2002年 | 31篇 |
2001年 | 22篇 |
2000年 | 17篇 |
1999年 | 8篇 |
1998年 | 15篇 |
1997年 | 14篇 |
1996年 | 16篇 |
1995年 | 12篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 13篇 |
1991年 | 14篇 |
1990年 | 5篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 19篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 5篇 |
1979年 | 14篇 |
1978年 | 8篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1972年 | 5篇 |
1971年 | 4篇 |
1970年 | 5篇 |
排序方式: 共有908条查询结果,搜索用时 15 毫秒
161.
The engagement of UK local authorities is vital if national government is to meet its climate change commitments. However, with no mandatory targets at local government level, other drivers must explain engagement. Using a Geographic Information System, this study compares the spatial distribution of action on climate change based on past actions and stated intentions to a suite of relevant independent variables. The Action Index created is among the first to quantify climate change engagement beyond a simple binary measure and provides a useful comparative study to recent work in the USA. The Index enables investigation of both mitigation and adaptation, which show different trends in relation to some variables. The study shows that action is strongest where the voting habits of the local population suggest environmental concern and where neighbouring local authorities are also engaging in action on climate change. Physical vulnerability to the effects of climate change is a motivator for action only where the dangers are obvious. Action is less likely where other resource-intensive issues such as crime and housing exist within a local authority area. 相似文献
162.
Donald Lyons 《Local Environment》2013,18(1):71-86
The continually increasing volume of the waste stream has led to numerous calls for strategies to close the loop on material use through industrial symbiosis strategies which direct used material and products (wastes) back to production processes. By use of a survey of recycling, remanufacturing and waste treatment firms in Texas, this paper asks if these firms can operate as a bridge between production and consumption/waste to efficiently increase the flow of used materials and products back to production processes at the local level. The results suggest that while most materials and used products are collected locally, only some can be re(consumed) locally. Moreover, the firms face negative perceptions about their activities from industry and the public at large that likely slow both the rate of entry of new firms into these markets and the expansion possibilities of existing firms. In addition, the types of conventions that characterize the interactions of more successful firms are not well developed in this sector(s). It is unlikely that recycling, remanufacturing and waste treatment firms can become central players in the production, consumption and waste cycle loop until society develops production design, marketing and consumption philosophies that include recycling and remanufacturing at a fundamental level. 相似文献
163.
John A. Litvaitis Jeffrey L. Norment Kelly Boland Kate O’Brien Rachel Stevens Donald Keirstead Thomas Lee James D. Oehler Jeffery M. Taylor Susan Bickford Matthew D. Tarr 《Environmental management》2013,52(6):1313-1319
Limiting the spread of invasive plants has become a high priority among natural resource managers. Yet in some regions, invasive plants are providing important habitat components to native animals that are at risk of local or regional extirpation. In these situations, removing invasive plants may decrease short-term survival of the at-risk taxa. At the same time, there may be a reluctance to expand invaded habitats to benefit at-risk species because such actions may increase the distribution of invasive plants. Such a dilemma can result in “management paralysis,” where no action is taken either to reduce invasive plants or to expand habitats for at-risk species. A pragmatic solution to this dilemma may be to develop an approach that considers site-specific circumstances. We constructed a “discussion tree” as a means of initiating conversations among various stakeholders involved with managing habitats in the northeastern USA to benefit several at-risk taxa, including New England cottontails (Sylvilagus transitionalis). Major components of this approach include recognition that expanding some invaded habitats may be essential to prevent extirpation of at-risk species, and the effective control of invasive plants is dependent on knowledge of the status of invasives on managed lands and within the surrounding landscape. By acknowledging that management of invasive plants is a complex issue without a single solution, we may be successful in limiting their spread while still addressing critical habitat needs. 相似文献
164.
Soils adjacent to chromated copper arsenate (CCA)-treated fence posts along a fence line transecting different soil series, parent material, drainage classes, and slope were used to determine which soil properties had the most influence on As spatial distribution and speciation. Metal distribution was evaluated at macroscopic (total metal concentration contour maps) and microscopic scales (micro-synchrotron X-ray fluorescence maps), As speciation was determined using extended X-ray absorption fine structure spectroscopy, and redox status and a myriad of other basic soil properties were elucidated. All geochemical parameters measured point to a condition in which the mobilization of As becomes more favorable moving down the topographic gradient, likely resulting through competition (Meh-P, SOM), neutral or slightly basic pH, and redox conditions that are favorable for As mobilization (higher Fe(II) and total-Fe concentrations in water extracts). On the landscape scale, with hundreds of kilometers of fence, the arsenic loading into the soil can be substantial (~8-12 kg km). Although a significant amount of the As is stable, extended use of CCA-treated wood has resulted in elevated As concentrations in the local environment, increasing the risk of exposure and ecosystem perturbation. Therefore, a move toward arsenic-free alternatives in agricultural applications for which it is currently permitted should be considered. 相似文献
165.
Donald B. Thompson 《Journal of Agricultural and Environmental Ethics》2011,24(2):165-194
The term natural is effective in the marketing of a wide variety of foods. This ambiguous term carries important meaning in Western culture.
To challenge an uncritical understanding of natural with respect to food and to explore the ambiguity of the term, the development of Western ideas of nature is first discussed. Personification and hypostasization of nature are given special emphasis. Leo Marx’s idea of the pastoral
design in literature is then used to explore the meaning of natural as applied to food, emphasizing Marx’s distinction between
a sentimental and a complex pastoral. The latter is applied to natural as a means of collapsing a dichotomy of man and nature to the idea of second nature. From this perspective an understanding of the industrialization of the food system and the importance of local and organic
food are considered. The extent to which processed foods might properly be considered natural is raised and discussed for
several common foods. Although marketing of natural foods might make us think that we consume nature, I suggest that what
is consumed is more appropriately second nature. I suggest that in order to maintain a critical perspective about one’s relationship
to the natural world, everyone should make an attempt to experience the complex pastoral with respect to at least something
that is consumed as food. When nature is understood as second nature in the context of a complex pastoral, the question of
whether a food or ingredient is to be considered natural is replaced by deliberative thought based on our best knowledge and
judgment, and the result will be less constrained by ideology. 相似文献
166.
Rosemary E. Golding Donald J. Colgan Guy Nelmes Tina Reutelshöfer 《Marine Biology》2011,158(6):1259-1269
DNA sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene were collected from estuarine snails in the genus
Phallomedusa to examine the effects of estuarine isolation on population structure and gene flow. Three clades were recovered, one corresponding
to Phallomedusa austrina and two others with the morphology of Phallomedusa solida. The haplotype diversity in all three clades indicated recent population expansion. Phallomedusa austrina was restricted to the west of a previous land bridge in the Bass Strait between mainland Australia and Tasmania, and P. solida to its east and to northern Tasmania. Phylogeographic analysis of P. austrina and P. solida shows strong geographic separation of species, but no local genetic structure indicative of regional or estuarine isolation.
The clades of P. solida exhibit substantial genetic divergence and were sympatric across their entire distribution in eastern Tasmania and mainland
Australia. Such a situation, which has not previously been observed in phylogeographic studies of southeast Australia, suggests
that P. solida has had a complex refugial history during periods of environmental challenge. 相似文献
167.
Rubenstein LZ Vivrette R Harker JO Stevens JA Kramer BJ 《Journal of Safety Research》2011,42(6):493-499
Background
Falls are a common, serious, and often unrecognized problem facing older adults. The objective of this study was to provide an initial clinical and statistical validation for a public health strategy of fall risk self-assessment by older adults using a Fall Risk Questionnaire (FRQ).Methods
Adults age 65 + (n = 40) were recruited at a Los Angeles Veterans Affairs (VA) medical facility and at a local assisted living facility. Participants completed the FRQ self-assessment and results were compared to a “gold standard” of a clinical evaluation of risks using the American/British Geriatrics Society guidelines to assess independent predictors of falls: history of previous falls, fear of falling, gait/balance, muscle weakness, incontinence, sensation and proprioception, depression, vision, and medications. For the comparison, we used an iterative statistical approach, weighing items based on relative risk.Results
There was strong agreement between the FRQ and clinical evaluation (kappa = .875, p < .0001). Individual item kappa values ranged from .305-.832. After dropping one FRQ item (vision risk) because of inadequate agreement with the clinical evaluation (kappa = .139, p = .321), the final FRQ had good concurrent validity.Conclusions
The FRQ goes beyond existing screening tools in that it is based on both evidence and clinical acceptability and has been initially validated with clinical examination data. A larger validation with longitudinal follow-up should determine the actual strength of the FRQ in predicting future falls. 相似文献168.
Charles T. Garten Deanne J. Brice Hector F. Castro Robin L. Graham Melanie A. Mayes Jana R. Phillips Wilfred M. Post Christopher W. Schadt Stan D. Wullschleger Donald D. Tyler Phillip M. Jardine Julie D. Jastrow Roser Matamala R. Michael Miller Kelly K. Moran Timothy W. Vugteveen R. Cesar Izaurralde Allison M. Thomson Tristram O. West James E. Amonette Jeffrey L. Smith 《Agriculture, ecosystems & environment》2011,140(1-2):289-297
Switchgrass (Panicum virgatum) is a perennial, warm-season grass that has been identified as a potential biofuel feedstock over a large part of North America. We examined above- and belowground responses to nitrogen fertilization in “Alamo” switchgrass grown in West Tennessee, USA. The fertilizer study included a spring and fall sampling of 5-year old switchgrass grown under annual applications of 0, 67, and 202 kg N ha?1 (as ammonium nitrate). Fertilization changed switchgrass biomass allocation as indicated by root:shoot ratios. End-of-growing season root:shoot ratios (mean ± SE) declined significantly (P ≤ 0.05) at the highest fertilizer nitrogen treatment (2.16 ± 0.08, 2.02 ± 0.18, and 0.88 ± 0.14, respectively, at 0, 67, and 202 kg N ha?1). Fertilization also significantly increased above- and belowground nitrogen concentrations and decreased plant C:N ratios. Data are presented for coarse live roots, fine live roots, coarse dead roots, fine dead roots, and rhizomes. At the end of the growing season, there was more carbon and nitrogen stored in belowground biomass than aboveground biomass. Fertilization impacted switchgrass tissue chemistry and biomass allocation in ways that potentially impact soil carbon cycle processes and soil carbon storage. 相似文献
169.
Maria Lumbierres Prabhat Raj Dahal Moreno Di Marco Stuart H. M. Butchart Paul F. Donald Carlo Rondinini 《Conservation biology》2022,36(3):e13851
Area of habitat (AOH) is defined as the “habitat available to a species, that is, habitat within its range” and is calculated by subtracting areas of unsuitable land cover and elevation from the range. The International Union for the Conservation of Nature (IUCN) Habitats Classification Scheme provides information on species habitat associations, and typically unvalidated expert opinion is used to match habitat to land-cover classes, which generates a source of uncertainty in AOH maps. We developed a data-driven method to translate IUCN habitat classes to land cover based on point locality data for 6986 species of terrestrial mammals, birds, amphibians, and reptiles. We extracted the land-cover class at each point locality and matched it to the IUCN habitat class or classes assigned to each species occurring there. Then, we modeled each land-cover class as a function of IUCN habitat with (SSG, using) logistic regression models. The resulting odds ratios were used to assess the strength of the association between each habitat and land-cover class. We then compared the performance of our data-driven model with those from a published translation table based on expert knowledge. We calculated the association between habitat classes and land-cover classes as a continuous variable, but to map AOH as binary presence or absence, it was necessary to apply a threshold of association. This threshold can be chosen by the user according to the required balance between omission and commission errors. Some habitats (e.g., forest and desert) were assigned to land-cover classes with more confidence than others (e.g., wetlands and artificial). The data-driven translation model and expert knowledge performed equally well, but the model provided greater standardization, objectivity, and repeatability. Furthermore, our approach allowed greater flexibility in the use of the results and uncertainty to be quantified. Our model can be modified for regional examinations and different taxonomic groups. 相似文献
170.
Thornton Grace L. Stevens Brian French Shannon K. Shirose Leonard J. Reggeti Felipe Schrier Nick Parmley E. Jane Reid Alexandra Jardine Claire M. 《Environmental science and pollution research international》2022,29(23):34137-34146
Environmental Science and Pollution Research - Anticoagulant rodenticides (ARs) are used globally to control rodent pest infestations in both urban and agricultural settings. It is well documented... 相似文献