首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   281篇
  免费   8篇
  国内免费   4篇
安全科学   11篇
废物处理   3篇
环保管理   41篇
综合类   37篇
基础理论   79篇
环境理论   1篇
污染及防治   80篇
评价与监测   16篇
社会与环境   20篇
灾害及防治   5篇
  2023年   1篇
  2022年   6篇
  2021年   10篇
  2020年   10篇
  2019年   8篇
  2018年   15篇
  2017年   6篇
  2016年   17篇
  2015年   8篇
  2014年   8篇
  2013年   18篇
  2012年   15篇
  2011年   25篇
  2010年   14篇
  2009年   19篇
  2008年   19篇
  2007年   14篇
  2006年   11篇
  2005年   11篇
  2004年   6篇
  2003年   8篇
  2002年   3篇
  2000年   5篇
  1999年   2篇
  1998年   1篇
  1997年   2篇
  1995年   1篇
  1994年   3篇
  1993年   3篇
  1992年   4篇
  1991年   1篇
  1990年   2篇
  1987年   1篇
  1985年   2篇
  1984年   2篇
  1982年   2篇
  1980年   1篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1971年   1篇
  1963年   1篇
  1960年   1篇
  1958年   1篇
  1946年   1篇
排序方式: 共有293条查询结果,搜索用时 937 毫秒
161.
162.
The distribution of the introduced European green crab, Carcinus maenas, was investigated in the central California embayments of Bodega Bay Harbor (BBH), Tomales Bay, and Bolinas Lagoon using baited traps and snorkel surveys. Adult green crabs were very spatially limited in all three embayments and occurred primarily in warm, shallow areas that lacked large native Cancer spp. crabs. The green crabs that were found in closest proximity to populations of Cancer spp. exhibited high levels of limb damage and loss; damage was strongly correlated with low ratios of intertidal area: edge, indicative of narrow areas of intertidal that are more easily accessed by large Cancer spp. moving up to forage during periods of tidal inundation. Up to 70% of the green crabs tethered in areas of BBH that are utilized by Cancer spp. experienced limb loss, while those tethered in the marsh, where there are no Cancer spp., were undamaged. The results suggest that the potential distribution of green crabs in the northeastern Pacific will be far less than has been predicted, and that their impacts may be largely attenuated through predation by and competition with native crab species.  相似文献   
163.
164.
Environmental Science and Pollution Research - Air toxics are airborne pollutants known or suspected to cause cancer or other serious health effects, including certain volatile organic compounds...  相似文献   
165.
Habitat heterogeneity can generate intraspecific diversity through local adaptation of populations. While it is becoming increasingly clear that population diversity can increase stability in species abundance, less is known about how population diversity can benefit consumers that can integrate across population diversity in their prey. Here we demonstrate cascading effects of thermal heterogeneity on trout-salmon interactions in streams where rainbow trout rely heavily on the seasonal availability of anadromous salmon eggs. Water temperature in an Alaskan stream varied spatially from 5 degrees C to 17.5 degrees C, and spawning sockeye salmon showed population differentiation associated with this thermal heterogeneity. Individuals that spawned early in cool regions of the 5 km long stream were genetically differentiated from those spawning in warmer regions later in the season. Sockeye salmon spawning generates a pulsed resource subsidy that supports the majority of seasonal growth in stream-dwelling rainbow trout. The spatial and temporal structuring of sockeye salmon spawn timing in our focal stream extended the duration of the pulsed subsidy compared to a thermally homogeneous stream with a single population of salmon. Further, rainbow trout adopted movement strategies that exploited the multiple pulses of egg subsidies in the thermally heterogeneous stream. Fish that moved to track the resource pulse grew at rates about 2.5 times higher than those that remained stationary or trout in the reference stream with a single seasonal pulse of eggs. Our results demonstrate that habitat heterogeneity can have important effects on the population diversity of dominant species, and in turn, influence their value to species that prey upon them. Therefore, habitat homogenization may have farther-reaching ecological effects than previously considered.  相似文献   
166.
Recently there has been a surge in the number of green roofs and façades (vegetation on the roofs & walls of a building) installed in the UK, with advocation of their use by policy-makers and claims that they are aesthetically pleasing and promote restoration. But these claims rely on generalisations from different landscapes, raising concerns about validity. The present study examined whether houses with vegetation would be more preferred than those without, be perceived as more beautiful and restorative, and have a more positive affective quality. Differences between types of building-integrated vegetation were also examined. Two studies were conducted: an online survey in which participants (N = 188) rated photographs of houses with and without vegetation on each of these measures, and interviews (N = 8) which examined preference and installation concerns. Results showed that houses with (some types of) building-integrated vegetation were significantly more preferred, beautiful, restorative, and had a more positive affective quality than those without. The ivy façade and meadow roof rated highest on each. These findings are consistent with other areas of landscape research and the claims of those in the industry, and suggest that building-integrated vegetation would be a valuable addition to the urban environment.  相似文献   
167.
We report on a qualitative investigation of the influence of emotions on the decision making of traders in four City of London investment banks, a setting where work has been predominantly theorized as dominated by rational analysis. We conclude that emotions and their regulation play a central role in traders' decision making. We find differences between high and low performing traders in how they engage with their intuitions, and that different strategies for emotion regulation have material consequences for trader behavior and performance. Traders deploying antecedent‐focused emotional regulation strategies achieve a performance advantage over those employing primarily response‐focused strategies. We argue that, in particular, response‐focused approaches incur a performance penalty, in part because of the reduced opportunity to combine analysis with the use of affective cues in making intuitive judgments. We discuss the implications for our understanding of emotion and decision making, and for traders' practice. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
168.
Increasing atmospheric CO2 equilibrates with surface seawater, elevating the concentration of aqueous hydrogen ions. This process, ocean acidification, is a future and contemporary concern for aquatic organisms, causing failures in Pacific oyster (Crassostrea gigas) aquaculture. This experiment determines the effect of elevated pCO2 on the early development of C. gigas larvae from a wild Pacific Northwest population. Adults were collected from Friday Harbor, Washington, USA (48°31.7′N, 12°1.1′W) and spawned in July 2011. Larvae were exposed to Ambient (400 μatm CO2), MidCO2 (700 μatm), or HighCO2 (1,000 μatm). After 24 h, a greater proportion of larvae in the HighCO2 treatment were calcified as compared to Ambient. This unexpected observation is attributed to increased metabolic rate coupled with sufficient energy resources. Oyster larvae raised at HighCO2 showed evidence of a developmental delay by 3 days post-fertilization, which resulted in smaller larvae that were less calcified.  相似文献   
169.
This research is concerned with effects and actions at the local level, where it is argued that local governing processes are key to developing sustainable communities. The roles of the citizen and of formal government are changing such that the implementation of sustainability praxis at the local level requires that citizens and governments reconsider both the meaning and techniques of governance. Indeed, how we are governed, participate in governing processes and internalise and accept the need for change will affect how local communities make constant and lasting a dynamic praxis of sustainability. Actors in local governments and communities may be crucial in this task—especially as facilitators, enablers, leaders and partners. In this paper we focus on the Huon Valley Council and some members of one of its communities. We examine how they are experimenting with partnerships as a form of governance to unify, control, mobilise and regulate the conduct of various actors, and how such partnerships may foster sustainability praxis in the Valley's diverse communities of place and interest.  相似文献   
170.
In this work we modified a theoretical model of acid deposition in the soil–vegetation interaction to be experimentally applicable. We simplified the expression of the mathematical model of dynamical complex systems by setting parameters into more simple groups, giving an easy-of-validate expression. By the theoretical model it was proposed the nonlinear response of vegetation to acid deposition, which can explain the occurrence of serious and unexpected damages to plantations and forests focused on the catastrophic nature of the effects of aluminum mobility on the vegetation.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号