全文获取类型
收费全文 | 741篇 |
免费 | 16篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 27篇 |
废物处理 | 30篇 |
环保管理 | 173篇 |
综合类 | 86篇 |
基础理论 | 172篇 |
污染及防治 | 168篇 |
评价与监测 | 51篇 |
社会与环境 | 51篇 |
灾害及防治 | 6篇 |
出版年
2022年 | 7篇 |
2021年 | 14篇 |
2020年 | 11篇 |
2019年 | 11篇 |
2018年 | 19篇 |
2017年 | 20篇 |
2016年 | 18篇 |
2015年 | 20篇 |
2014年 | 16篇 |
2013年 | 82篇 |
2012年 | 30篇 |
2011年 | 42篇 |
2010年 | 24篇 |
2009年 | 24篇 |
2008年 | 41篇 |
2007年 | 48篇 |
2006年 | 35篇 |
2005年 | 18篇 |
2004年 | 19篇 |
2003年 | 38篇 |
2002年 | 24篇 |
2001年 | 10篇 |
2000年 | 13篇 |
1999年 | 5篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 18篇 |
1993年 | 11篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 10篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1986年 | 6篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1917年 | 1篇 |
排序方式: 共有764条查询结果,搜索用时 843 毫秒
551.
The Delphi approach to the mediation of environmental disputes 总被引:1,自引:1,他引:1
Environmental disputes, in many countries, have taken on a ritualistic character. Their persistence, even after prolonged analysis and debate, suggests that they result from ideological rather than factual differences. Since no single ideological position holds a monopoly on the truth, effective environmental management would seem to require an integration of views, the problem being how to achieve this. One approach to this problem is illustrated in this article. Two factions in the spruce budworm dispute in New Brunswick, Canada, were engaged in a mediation exercise using the Delphi method. Details of the design and execution of this form of mediation are provided, together with an evaluation of the Delphi's effectiveness in this context. 相似文献
552.
Alan Miller 《The Environmentalist》1982,2(3):223-231
Summary This is a paper about problem-solving styles in Environmental Management and the specific deficiencies in these styles that
might be groupd under the label ‘tunnel vision’. The latter, a form of selective attention, contributes to inadequate problem-formulation,
partial solutions to complex problems and to the generation of even more intractable, additional problems. Examples of tunnel
vision in military and environmental decision-making are discussed, together with the situational, personal and educational
factors that exacerbate its influence. The paper concludes with some recommendations for changes in professional education
that might help to recduce the occurrence of tunnel vision.
Dr Alan Miller who is now associate professor at the University of New Brunswick received his training in biology (in England)
and ecology (in Canada). He then spent several years pursuing research at the Northwest Institute for Medical Research in
Chicago, USA. A growing interest in the human aspects of environmental and medical problems led to a further graduate study
in psychology, followed by teaching positions in Ireland and Canada. His current interests include: the education of environmental
professional; the psychosocial problems involved in environmental management, and, the problems inherent in interdisciplinary
project groups. 相似文献
553.
Alan R. Hill 《Journal of the American Water Resources Association》1981,17(4):627-634
: The export of dissolved molybdate reactive phosphorus (DMRP) from 22 watersheds in the Duffin Creek drainage basin near Toronto Ontario was measured over a 25-month period. The annual average loss varied from 0.027 to 2.11 kg P/ha. Phosphorus levels in a number of watersheds were strongly influenced by effluent from a sewage treatment plant which contributed about 68 percent of the annual DMRP input to Duffin Creek. An analysis of 12 watersheds which did not contain major point pollution sources revealed that DMRP concentration and losses had a significant positive correlation with crop area and a strong negative association with forest, abandoned farm land, and area of sand + sandy loam soils. The causal relationships underlying these simple correlations are difficult to evaluate because of considerable multicollinearity between land use, soil, and topographic variables. Analysis of a mass balance for the downstream reaches of Duffin Creek indicated that there was considerable retention of phosphorus in the river channel particularly during summer low flows. 相似文献
554.
Recovery of lotic periphyton communities after disturbance 总被引:2,自引:0,他引:2
Periphyton communities represent potentially excellent candidates for assessing the recovery of lotic ecosystems after disturbance.
These communities are ubiquitous, relatively easy to sample and measure (in terms of total community biomass), have short
generation times, and may influence the recovery rates of higher trophic levels. The first section of this article analyzes
how site availability, species availability, and differential species performance influence periphyton successional dynamics.
This background information provides a foundation for understanding how periphytic organisms respond after a disturbance.
The second section of this article analyzes how periphyton communities respond to four different types of disturbance (flood
events, desiccation, organic nutrient enrichment, and toxic metal exposure). Although data are limited, it is concluded that
the fast growth rates and short generation times of periphytic organisms, coupled with their flexible life history strategies
and good dispersal ability, allow lotic periphyton communities to recover relatively quickly after a disturbance. In addition,
disturbance type and severity, local environmental conditions, and site-specific factors also will influence recovery rates.
Future research needs include a better understanding of: (1) what periphyton property(ies) would serve as the best index of
recovery; (2) whether or not the robustness of this index varies among different environments and different disturbances;
(3) interactions between autotrophs and heterotrophs within the periphyton mat, particularly with respect to nutrient cycling;
(4) competitive interactions among organisms; (5) functional redundancy of organisms; and (6) the influence of the riparian
zone and channel geomorphology on periphyton recovery rates. 相似文献
555.
Alan Ewert 《Environmental management》1990,14(2):179-184
Mount St. Helens provides an interesting case study of a forest and wildland area that has been radically altered in recent
history. As a result of volcanic activity, the recreation environment has changed with respect to the setting, climbing opportunities,
and motivations for mountaineering. An evaluation process using both qualitative and quantitative methods was developed to
determine what the motivations, demographic characteristics, and preferred management techniques were for the posteruption
Mount St. Helens mountain-climbing visitor. Results suggest that changes have occurred in the “new” or posteruption climbing
visitor. These changes have not all been congruent with those anticipated by management. For example, the climbing visitor
is now less interested in climbing opportunities and more concerned with seeing the crater and other volcanic-related features.
This article discusses the findings of this research in light of how resource managers might consider the issue of visitor
changes in both demands and types of uses. For example, determining quota numbers based on sociological determinants (e.g.,
desire for solitude) need to be firmly grounded in who the visitors actually are rather than who they were. Consequently,
management tools such as the Recreational Opportunity Spectrum (ROS) and Limits of Acceptable Change (LAC) may need to be
altered to accommodate a changing resource or visitor base. These and other findings have implications for the future management
practices of the Mount St. Helens area and other environments where the recreation resources have undergone rapid and profound
change. 相似文献
556.
Snow was used as a collection medium to examine 1,3,5-hexahydro-1,3,5-trinitrotriazine (RDX) and 2,4,6-trinitrotoluene (TNT) residues post-detonation of 60-, 81-, and 120-mm mortar rounds, 105- and 155-mm howitzer rounds, M67 hand grenades, 40-mm rifle grenades, and blocks of C4. Residue-covered snow samples were collected, processed, and analyzed for explosives without cross-contamination from previous detonations and other potential matrix interferences. Detonation trials were performed following standard military live-fire and blow-in-place techniques. When possible, replicate munitions were detonated under similar conditions to provide a more reliable estimation of the mass of unconsumed high explosive residues. Overall the amount of energetic residues deposited from live-fire detonations were considerably less than the energetic residues deposited by blow-in-place detonations. 相似文献
557.
Air pollution control devices (APCDs) are not compulsory for medical waste incinerators (MWIs) in developing countries. In South Africa, combustion gases are usually vented directly to the atmosphere at temperatures greater than the formation temperature of dioxin. The possibility of dioxin formation outside the incinerator stack has been hypothesized. A plume model has been developed and tested in the wind tunnel with a scale model of an incinerator stack. The plume temperature and trajectory predictions of the plume model were verified within a +/- 3% experimental accuracy. Using South African data, the plume model predicts that the residence time of gases in the temperature range of 150-450 degrees C in a plume is 1.3 sec on average for 5% of a year (18 days) at meteorological conditions resulting in wind speeds of less than 1 m/sec. Two published dioxin formation models were used to assess the probability of dioxin formation in the plume. The formation models predict that the average polychlorinated dibenzodioxins/furans (PCDD/Fs) formed in the plume will exceed the stack emission regulations in South Africa of 0.2 ng/Nm3 toxic equivalent quotient (TEQ) by between 2 and 40 times. The calculated concentrations do not include additional gaseous PCDD/F compounds that may be formed at high-temperature post-combustion zones through pyrosynthesis mechanisms. 相似文献
558.
559.
A Global Perspective on Large Carnivore Conservation 总被引:4,自引:0,他引:4
The recent reintroduction of the gray wolf ( Canis lupus ) to Yellowstone signifies a constructive change, but the overall record in the United States on large carnivore conservation remains poor. Many developing countries are determined to do a better job of conserving predators, including their critical habitat and prey populations. We describe current efforts to protect tigers ( Panther tigris ), jaguars ( Panthera onca ), and large-scale forest habitat in Asia, Central America, and Africa. These initiatives take a comprehensive approach that includes biological field research, the identification of local human interests, and a growing recognition of the need for cooperation across political lines. Though often supported by U.S. technical assistance, this international experience could be used better to inform and improve carnivore conservation efforts in North America. Failure to improve our domestic performance or to fully appreciate the contributions of far less developed countries could weaken global efforts to maintain and restore populations of large carnivores. 相似文献
560.
Andrew M Latimer Shanshan Wu Alan E Gelfand John A Silander 《Ecological applications》2006,16(1):33-50
Models of the geographic distributions of species have wide application in ecology. But the nonspatial, single-level, regression models that ecologists have often employed do not deal with problems of irregular sampling intensity or spatial dependence, and do not adequately quantify uncertainty. We show here how to build statistical models that can handle these features of spatial prediction and provide richer, more powerful inference about species niche relations, distributions, and the effects of human disturbance. We begin with a familiar generalized linear model and build in additional features, including spatial random effects and hierarchical levels. Since these models are fully specified statistical models, we show that it is possible to add complexity without sacrificing interpretability. This step-by-step approach, together with attached code that implements a simple, spatially explicit, regression model, is structured to facilitate self-teaching. All models are developed in a Bayesian framework. We assess the performance of the models by using them to predict the distributions of two plant species (Proteaceae) from South Africa's Cape Floristic Region. We demonstrate that making distribution models spatially explicit can be essential for accurately characterizing the environmental response of species, predicting their probability of occurrence, and assessing uncertainty in the model results. Adding hierarchical levels to the models has further advantages in allowing human transformation of the landscape to be taken into account, as well as additional features of the sampling process. 相似文献