全文获取类型
收费全文 | 1794篇 |
免费 | 17篇 |
国内免费 | 23篇 |
专业分类
安全科学 | 46篇 |
废物处理 | 62篇 |
环保管理 | 245篇 |
综合类 | 401篇 |
基础理论 | 346篇 |
环境理论 | 1篇 |
污染及防治 | 514篇 |
评价与监测 | 96篇 |
社会与环境 | 109篇 |
灾害及防治 | 14篇 |
出版年
2023年 | 20篇 |
2022年 | 18篇 |
2021年 | 29篇 |
2020年 | 21篇 |
2019年 | 25篇 |
2018年 | 47篇 |
2017年 | 50篇 |
2016年 | 60篇 |
2015年 | 72篇 |
2014年 | 76篇 |
2013年 | 84篇 |
2012年 | 80篇 |
2011年 | 115篇 |
2010年 | 97篇 |
2009年 | 99篇 |
2008年 | 90篇 |
2007年 | 98篇 |
2006年 | 80篇 |
2005年 | 54篇 |
2004年 | 80篇 |
2003年 | 44篇 |
2002年 | 62篇 |
2001年 | 67篇 |
2000年 | 30篇 |
1999年 | 17篇 |
1998年 | 17篇 |
1997年 | 25篇 |
1996年 | 19篇 |
1995年 | 31篇 |
1994年 | 19篇 |
1993年 | 6篇 |
1992年 | 14篇 |
1991年 | 24篇 |
1990年 | 11篇 |
1989年 | 18篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1979年 | 9篇 |
1970年 | 6篇 |
1969年 | 4篇 |
1965年 | 4篇 |
1962年 | 3篇 |
1960年 | 4篇 |
1959年 | 3篇 |
1954年 | 3篇 |
排序方式: 共有1834条查询结果,搜索用时 15 毫秒
991.
Sophia Winkler-Schor Carena J. van Riper Adam Landon Rose Keller 《Conservation biology》2020,34(6):1404-1415
Values are the fundamental reasons why people engage in conservation behaviors. Recent research has called for a more refined approach to studying values in a way that accounts for the concept of eudaimonia. However, the empirical properties for a eudaimonic value scale have not been tested given that previous investigations have remained at the theoretical level. Drawing from an on-site survey of visitors to Denali National Park and Preserve, Alaska, we used a latent profile analysis to better understand the expression of multiple values of nature. Specifically, we segmented respondents by their value orientations with a particular focus on evaluating eudaimonic and hedonic values, alongside the established dimensions of altruistic, biospheric, and egoistic values. We identified 4 distinct subgroups defined by value orientations and validated these subgroups based on measures of conservation behavior and sociodemographic characteristics (e.g., age). These results indicated campaign messaging should harness a combination of eudaimonic, biospheric, and altruistic values to propel individual behavior. We also observed that hedonic and egoistic values defined how people related to nature and played a role, albeit less pronounced, in motivating them to take action. Our study is one of the first efforts to operationalize eudaimonia in a conservation context; thus, we have opened a new avenue for protected-area managers to align their strategies with the underlying values of stakeholders. 相似文献
992.
High-latitude ecosystems store large amounts of carbon (C); however, the C storage of these ecosystems is under threat from both climate warming and increased levels of herbivory. In this study we examined the combined role of herbivores and climate warming as drivers of CO2 fluxes in two typical high-latitude habitats (mesic heath and wet meadow). We hypothesized that both herbivory and climate warming would reduce the C sink strength of Arctic tundra through their combined effects on plant biomass and gross ecosystem photosynthesis and on decomposition rates and the abiotic environment. To test this hypothesis we employed experimental warming (via International Tundra Experiment [ITEX] chambers) and grazing (via captive Barnacle Geese) in a three-year factorial field experiment. Ecosystem CO2 fluxes (net ecosystem exchange of CO2, ecosystem respiration, and gross ecosystem photosynthesis) were measured in all treatments at varying intensity over the three growing seasons to capture the impact of the treatments on a range of temporal scales (diurnal, seasonal, and interannual). Grazing and warming treatments had markedly different effects on CO2 fluxes in the two tundra habitats. Grazing caused a strong reduction in CO2 assimilation in the wet meadow, while warming reduced CO2 efflux from the mesic heath. Treatment effects on net ecosystem exchange largely derived from the modification of gross ecosystem photosynthesis rather than ecosystem respiration. In this study we have demonstrated that on the habitat scale, grazing by geese is a strong driver of net ecosystem exchange of CO2, with the potential to reduce the CO2 sink strength of Arctic ecosystems. Our results highlight that the large reduction in plant biomass due to goose grazing in the Arctic noted in several studies can alter the C balance of wet tundra ecosystems. We conclude that herbivory will modulate direct climate warming responses of Arctic tundra with implications for the ecosystem C balance; however, the magnitude and direction of the response will be habitat-specific. 相似文献
993.
Separating the effects of partial submergence and soil oxygen demand on plant physiology 总被引:3,自引:0,他引:3
In wetlands, a distinct zonation of plant species composition occurs along moisture gradients, due to differential flooding tolerance of the species involved. However, "flooding" comprises two important, distinct stressors (soil oxygen demand [SOD] and partial submergence) that affect plant survival and growth. To investigate how these two flooding stressors affect plant performance, we executed a factorial experiment (water depth x SOD) for six plant species of nutrient-rich and nutrient-poor conditions, occurring along a moisture gradient in Dutch dune slacks. Physiological, growth, and biomass responses to changed oxygen availability were quantified for all species. The responses were consistent with field zonation, but the two stressors affected species differently. Increased SOD increased root oxygen deprivation, as indicated by either raised porosity or increased alcohol dehydrogenase (ADH) activity in roots of flood-intolerant species (Calamagrostis epigejos and Carex arenaria). While SOD affected root functioning, partial submergence tended more to reduce photosynthesis (as shown both by gas exchange and 13C assimilation), leaf dark respiration, 13C partitioning from shoots to roots, and growth of these species. These processes were especially affected if the root oxygen supply was depleted by a combination of flooding and increased SOD. In contrast, the most flood-tolerant species (Juncus subnodulosus and Typha latifolia) were unaffected by any treatment and maintained high internal oxygen concentrations at the shoot : root junction and low root ADH activity in all treatments. For these species, the internal oxygen transport capacity was well in excess of what was needed to maintain aerobic metabolism across all treatments, although there was some evidence for effects of SOD on their nitrogen partitioning (as indicated by 865N values) and photosynthesis. Two species intermediate in flooding tolerance (Carex nigra and Schoenus nigricans) responded more idiosyncratically, with different parameters responding to different treatments. These results show that partial submergence and soil flooding are two very different stressors to which species respond in different ways, and that their effects on physiology, survival, and growth are interactive. Understanding species zonation with water regimes can be improved by a better appreciation of how these factors affect plant metabolism independently and interactively. 相似文献
994.
995.
Irene T. M. Lindenburg Jeanine M. van Klink Vivianne E. H. J. Smits-Wintjens Inge L. van Kamp Dick Oepkes Enrico Lopriore 《黑龙江环境通报》2013,33(9):815-822
Perinatal survival rates after intrauterine transfusions (IUT) for red cell alloimmunisation now exceed 90%, which demonstrates the safety and efficacy of one of the most successful procedures in fetal therapy. However, improved perinatal survival could lead to an increased number of children with long-term disabilities. The importance of long-term follow-up studies in fetal therapy lies in both the necessity of evaluation of antenatal management as well as in evidence-based preconceptional and prenatal counselling. This review describes the possible long-term cardiovascular and neurodevelopmental sequelae after IUT treatment for different indications including red cell alloimmunisation, parvovirus B19 infection, fetomaternal haemorrhage and twin anaemia-polycythaemia sequence. © 2013 John Wiley & Sons, Ltd. 相似文献
996.
997.
van Oudenhove L Billoir E Boulay R Bernstein C Cerdá X 《Die Naturwissenschaften》2011,98(12):1009-1017
In Mediterranean habitats, temperature affects both ant foraging behaviour and community structure. Many studies have shown
that dominant species often forage at lower temperature than subordinates. Yet, the factors that constrain dominant species
foraging activity in hot environments are still elusive. We used the dominant ant Tapinoma nigerrimum as a model species to test the hypothesis that high temperatures hinder trail following behaviour by accelerating pheromone
degradation. First, field observations showed that high temperatures (> 30°C) reduce the foraging activity of T. nigerrimum independently of the daily and seasonal rhythms of this species. Second, we isolated the effect of high temperatures on pheromone
trail efficacy from its effect on worker physiology. A marked substrate was heated during 10 min (five temperature treatments
from 25°C to 60°C), cooled down to 25°C, and offered in a test choice to workers. At hot temperature treatments (>40°C), workers
did not discriminate the previously marked substrate. High temperatures appeared therefore to accelerate pheromone degradation.
Third, we assessed the pheromone decay dynamics by a mechanistic model fitted with Bayesian inference. The model predicted
ant choice through the evolution of pheromone concentration on trails as a function of both temperature and time since pheromone
deposition. Overall, our results highlighted that the effect of high temperatures on recruitment intensity was partly due
to pheromone evaporation. In the Mediterranean ant communities, this might affect dominant species relying on chemical recruitment,
more than subordinate ant species, less dependent on chemical communication and less sensitive to high temperatures. 相似文献
998.
Margit van Wessel Ronald van Buuren Cees van Woerkum 《Journal of Environmental Planning and Management》2015,58(1):156-174
This paper is a case study of a team of Dutch water managers who saw that to achieve flexibility in planning they needed to engage with organisational control requirements. Rather than approaching flexibility normatively, as much planning literature does, this paper presents a case of flexibility empirically – as something actors negotiate through their strategising within planning practice, within their organisational context. The analysis shows the importance of approaching flexibility in planning as an intra-organisational issue, presents insights on the strategies actors employ in negotiating flexibility and control intra-organisationally, and points to the political nature of dynamics between flexibility and control. 相似文献
999.
Jeroen van der Heijden 《Journal of Environmental Planning and Management》2015,58(6):1034-1057
This paper addresses a current trend of New Environmental Governance (NEG). It examines whether NEG is able to overcome a series of complex regulatory barriers and market shortfalls that stand in the way of carbon emissions reductions in the building sector. Building on an evaluation of 20 NEG arrangements from Australia and the Netherlands, it discusses the limits of the effective implementation and use of NEG in this sector. The paper concludes by suggesting three strategies to improve the performance of NEG arrangements in the building sector. 相似文献
1000.
Nivine H. Abbas Irna van der Molen Manal R. Nader Jon C. Lovett 《Journal of Environmental Planning and Management》2015,58(9):1511-1529
This research investigates how trust plays a role in environmental management in North Lebanon, which has suffered repeated episodes of armed conflict in recent times. Previous studies have shown that environmental problems have increased and that the government has been unable to address these, even during periods of relative peace. We examined trust as a factor that contributes to, or hampers, environmental management. Our analysis drew on a survey in 2011 involving 499 citizens. The results demonstrated that, according to citizens, the lack of trust between citizens, and between citizens and the public sector, is a key factor obstructing effective environmental management. The results indicate the level of correlation between how trusting people are; how citizens participate; and how people perceive government legitimacy. 相似文献