全文获取类型
收费全文 | 474篇 |
免费 | 24篇 |
国内免费 | 31篇 |
专业分类
安全科学 | 33篇 |
废物处理 | 18篇 |
环保管理 | 76篇 |
综合类 | 98篇 |
基础理论 | 110篇 |
环境理论 | 2篇 |
污染及防治 | 125篇 |
评价与监测 | 32篇 |
社会与环境 | 28篇 |
灾害及防治 | 7篇 |
出版年
2023年 | 10篇 |
2022年 | 23篇 |
2021年 | 21篇 |
2020年 | 9篇 |
2019年 | 21篇 |
2018年 | 24篇 |
2017年 | 21篇 |
2016年 | 31篇 |
2015年 | 24篇 |
2014年 | 33篇 |
2013年 | 48篇 |
2012年 | 19篇 |
2011年 | 38篇 |
2010年 | 23篇 |
2009年 | 20篇 |
2008年 | 23篇 |
2007年 | 15篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 16篇 |
2002年 | 15篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1973年 | 1篇 |
1966年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有529条查询结果,搜索用时 406 毫秒
101.
Most woody plants contain a diverse array of plant secondary metabolites (PSMs) that deter vertebrate herbivores. However,
mammalian folivores have evolved a complex of physiological and behavioural strategies to counter these compounds, leading
to the development of an “evolutionary arms race”. Marsupial folivores are ideal models to investigate the role of PSMs in
the interaction between the external foraging environment and the digestive physiology of mammalian herbivores, as we have
a very strong understanding of the diversity and modes of action of PSMs in Eucalyptus, as well as the mechanisms by which animals overcome the effects of these compounds. Studies of marsupial folivores have
benefited from the facts that: these herbivores subsist on relatively poor quality diets; they include feeding types from
specialist species such as the koala, to generalists; and life history factors such as maternal investment in reproduction
can be measured more easily than in eutherians. Here, we describe patterns of spatial variation in the types and distributions
of plant secondary metabolites in Australian forests and discuss how this variation influences foraging behaviour, habitat
selection and life history strategies in arboreal, folivorous marsupials. We also provide a summary of our understanding of
the mechanisms by which marsupials detect and regulate their intake of toxic compounds. While our examples are drawn largely
from studies of the interaction between marsupials and Eucalyptus, this knowledge is applicable to advancing our understanding of interactions in plant–mammal systems more broadly. We also
identify and discuss key areas that should be the focus of future research. 相似文献
102.
103.
104.
Ben Drake James C. R. Smart Mette Termansen Klaus Hubacek 《Regional Environmental Change》2013,13(3):649-659
Many regulating ecosystem services exhibit non-excludability and non-rivalry characteristics akin to public goods. This makes it unlikely that such regulating ecosystem services will attract a price in the marketplace. Policymakers, therefore, find difficulties in determining a correct economic valuation for regulating ecosystem services, with potentially severe consequences for aligning policy for ecosystem service provision with public preferences for service delivery. This research used a choice modelling approach to estimate public preferences for delivery of two regulating ecosystem services; reductions in the flood risk to the British city of York (implemented by filling in drainage ditches in peat moorland further up the catchment), and a reduction in CO2 emissions (implemented by planting Poplar trees for biomass either locally in the study area or elsewhere in the UK). The choice experiment presented respondents with options providing different levels of CO2 reduction, implemented locally or nationally, and different levels of flood risk reduction, at a range of different prices, with a tax as the payment vehicle. Subsequent analysis with latent class (LC) models showed considerable heterogeneity of preference among respondents, particularly with regard to the location of tree planting for CO2 reduction. One LC segment showed a significant preference for achieving a high level CO2 reduction through national, as opposed to local tree planting, potentially indicating the existence of NIMBYism. The same LC segment displayed a preference for moderate reductions in the flood risk to York, even though this would deliver no personal benefit for a substantial proportion of the segment. This could, therefore, indicate altruistic behaviour towards geographically proximate beneficiaries. 相似文献
105.
Ben Vanpeperstraete Sébastien Duyck Medani P. Bhandari Janis Brizga Leida Rijnhout Sylvia Lorek A. Peter Castro Chiung Ting Chang Herman Daly Robert J. Didham Gianluca Ferraro Oliver Greenfield Ashok Khosla Ernst Ulrich von Weizsäcker Birgit Lode Simon Miles Henrique Pacini Semida Silveira Leisa Perch Jaap Rijnsburger Mukul Sanwal Sameera Savarala S. Jacob Scherr Kallidaikurichi E. Seetharam A.M.M. Adeeb Donna Shepherd Adrian Smith Lisinka Ulatowska Alice Vincent Werner John 《Natural resources forum》2011,35(4):334-342
106.
I. Ben TaloubaL. Balland N. Mouhab M.A. Abdelghani-Idrissi 《Journal of Loss Prevention in the Process Industries》2011,24(4):391-396
The thermal stability of organic peroxides (cumene hydroperoxide 80 wt% and dicumyl peroxide) was studied by means of calorimetric measurement (DSC, TA Q1000) in an isotherm mode and a dynamic mode. Analysis of power profiles released in the isothermal mode was combined with the analysis of the decomposed compounds by a gas chromatograph/mass spectrometer (GC/MS) to determine the reaction mechanisms corresponding to each of the two reactions. In this work, a methodology for estimating kinetic parameters was based on the comparison of the power profile (dynamic mode) given by the model to that obtained experimentally by changing the parameters values. Parameter estimation is achieved using the mixed estimation method where a genetic algorithm is combined with a locally convergent method. 相似文献
107.
Ben B. Chapman Lesley J. Morrell Jens Krause 《Behavioral ecology and sociobiology》2009,63(12):1757-1763
The environment is profoundly important in shaping many aspects of animal phenotype, including courtship and mating behaviours.
Courtship displays rely upon the transmission of visual information from the signaller to the receiver, which means they are
likely to be less effective in visually poor conditions such as at low light or in turbid ecosystems. One might therefore
predict that in visually poor environments it would be beneficial for individuals to plastically adjust their mating behaviour
to maximise mating success. Here, we investigate the impact of the developmental and current visual environment (light intensity)
upon male mating behaviour in the Trinidadian guppy Poecilia reticulata. Male guppies have two different mating tactics: They can court females with a visual sigmoid display or attempt to circumvent
female choice by attempting a non-consensual copulation (gonapodium thrust). We reared juvenile guppies in low light and relatively
high light intensities for 5 months before observing individual males for mating behaviour in both light conditions. We found
that the current light environment is important in determining the frequency of both sigmoidal courtship displays and non-consensual
copulation attempts. Males increase the frequency of sigmoidal displays at relatively high light and increase non-consensual
mating attempts at low light, suggesting that males compensate for poor visual conditions via an adjustment in tactics. We
also find a significant correlation in courtship effort between the different light environments, suggesting that there is
individual consistency across time and context for this trait. Developmental environment was less important. However, we found
that fish reared at lower light intensities continued to employ sigmoidal displays despite the poor current visual environment.
Our data show that male mating behaviour is phenotypically plastic in response to recent light environment. This may have
implications for understanding how animals cope with anthropogenic environmental change. 相似文献
108.
Erin H. Gillam Gary F. McCracken John K. Westbrook Ya-Fu Lee Michael L. Jensen Ben B. Balsley 《Behavioral ecology and sociobiology》2009,64(1):69-79
Bats alter their echolocation in response to changes in ecological and behavioral conditions, but little is known about how
they adjust call structure in response to changes in altitude. We examined altitudinal variation in the echolocation of Brazilian
free-tailed bats, Tadarida brasiliensis, a species known to fly to altitudes of 3,000 m above the ground. From 50.2 h of recordings, we analyzed 113 high-quality
echolocation call sequences recorded from 0 to 862 m above ground level. Bats flying near the ground used shorter, higher-frequency,
broader-bandwidth calls compared to bats at higher altitudes, an effect likely due to the greater levels of echo-producing
clutter (i.e., vegetation, buildings) found near the ground. When ground-level recordings are excluded, bats continue to shift
towards the use of longer-duration, lower-frequency, narrower-bandwidth calls with increasing altitude. We propose that the
observed high-altitude changes in call structure are a response to changing acoustic attenuation rates and/or decreasing insect
densities at higher altitudes. 相似文献
109.
Due to the lack of data on hydraulic-jump dynamics in very large channels, the present paper describes the main characteristics
of the velocity field and turbulence in a large rectangular channel with a width of 4 m. Although a hydraulic jump is always
treated as a wave that is transversal to the channel wall, in the case of this study it has a trapezoidal front shape, first
starting from a point at the sidewalls and then developing downstream in an oblique manner, finally giving rise to a trapezoidal
shape. The oblique wave front may be regarded as a lateral shockwave that arises from a perturbation at a certain point of
the lateral wall and travels obliquely toward the centreline of the channel. The experimental work was carried out at the
Coastal Engineering Laboratory of the Water Engineering and Chemistry Department of the Technical University of Bari (Italy).
In addition to the hydraulic jump formation, a large recirculating flow zone starts to develop from the separating point of
the lateral shock wave and a separate boundary layer occurs. Intensive measurements of the streamwise and spanwise flow velocity
components along one-half width of the channel were taken using a bidimensional Acoustic Doppler Velocimeter (ADV). The water
surface elevation was obtained by means of an ultrasonic profiler. Velocity vectors, transversal velocity profiles, turbulence
intensities and Reynolds shear stresses were all investigated. The experimental results of the separated boundary layer were
compared with numerical predictions and related work presented in literature and showed good agreement. The transversal velocity
profiles indicated the presence of adverse pressure gradient zones and the law of the wall appears to govern the region around
the separated boundary layer. 相似文献
110.
单室MFC型生物毒性传感器对重金属离子的检测研究 总被引:2,自引:0,他引:2
构建了单室微生物燃料电池(air-cathode microbial fuel cell,ACMFC)型生物毒性传感器,以含重金属离子(Cd2+、Cu2+)人工配水为检测对象,分析了有毒物质对检测仪的抑制率与有毒物质浓度的线性关系.结果表明,①单室MFC型生物毒性传感器结构简单,操作方便,灵敏度较高,可用于水体重金属离子(Cd2+、Cu2+)生物毒性的快速检测;②在实验条件下,该生物毒性传感器检测时间4h,清洗时间2~10min,恢复时间4h;③检测结果显示,实验室自配Cd2+、Cu2+及其混合液IC20值分别为0.6、0.8和0.25mg/L,有毒物质浓度与MFC产电量的抑制率呈显著正相关,相关系数分别为0.9960、0.9744和0.9907. 相似文献