全文获取类型
收费全文 | 278篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 12篇 |
废物处理 | 10篇 |
环保管理 | 23篇 |
综合类 | 53篇 |
基础理论 | 76篇 |
污染及防治 | 68篇 |
评价与监测 | 23篇 |
社会与环境 | 14篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 8篇 |
2016年 | 18篇 |
2015年 | 10篇 |
2014年 | 14篇 |
2013年 | 21篇 |
2012年 | 22篇 |
2011年 | 25篇 |
2010年 | 15篇 |
2009年 | 19篇 |
2008年 | 20篇 |
2007年 | 17篇 |
2006年 | 10篇 |
2005年 | 9篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1985年 | 2篇 |
1981年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有282条查询结果,搜索用时 15 毫秒
111.
Effects of the 2008 flood on economic performance and food security in Yemen: a simulation analysis
下载免费PDF全文
![点击此处可从《Disasters》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Extreme weather events such as floods and droughts can have devastating consequences for individual well being and economic development, in particular in poor societies with limited availability of coping mechanisms. Combining a dynamic computable general equilibrium model of the Yemeni economy with a household‐level calorie consumption simulation model, this paper assesses the economy‐wide, agricultural and food security effects of the 2008 tropical storm and flash flood that hit the Hadramout and Al‐Mahrah governorates. The estimation results suggest that agricultural value added, farm household incomes and rural food security deteriorated long term in the flood‐affected areas. Due to economic spillover effects, significant income losses and increases in food insecurity also occurred in areas that were unaffected by flooding. This finding suggests that while most relief efforts are typically concentrated in directly affected areas, future efforts should also consider surrounding areas and indirectly affected people. 相似文献
112.
113.
The study investigated whether plasmatic parameters in fish such as Cl- content could serve as physiological indicators to evaluate water quality. The variations of plasma Cl- content in two fish species caught in a wide range of rivers representative of the hydrographic system of Lorraine (N-E France) were investigated. First, we studied autochthonous populations of chub (Leuciscus cephalus) which is a widespread species in the rivers of Lorraine. Organisms living in highly mineralised rivers (>1500 microScm(-1))--either naturally or due to salt mine contamination--showed plasma Cl- content significantly greater than organisms living in river with a lower mineralisation. Second, we investigated plasma Cl- content of brown trout (Salmo trutta fario) in poorly mineralised streams (<80 microS cm(-1)) with different degrees of acidification, both on autochthonous and transferred organisms. While indigenous trout maintained their Cl- content even in the acidic streams, transferred trout exhibited an important decrease of Cl- content after 48 h of exposure under acidic conditions. 相似文献
114.
Adjustment of parental effort to manipulated foraging ability in a pelagic seabird,the thin-billed prion Pachyptila belcheri 总被引:6,自引:0,他引:6
Henri Weimerskirch Olivier Chastel Luc Ackermann 《Behavioral ecology and sociobiology》1995,36(1):11-16
An experiment was designed to examine in a long-lived seabird, the thin-billed prion (Pachyptila belcheri), how adults adjust their food provisioning strategy when their foraging abilities are reduced and when the chick's needs are increased. To reduce the foraging abilities of adults we impaired their flying ability by removing some flight feathers (handicapped), and to increase the food needs of the chick one parent was retained (single). Birds made either short foraging trips lasting 1–3 days, or long trips lasting 5–9 days. Control birds alternated long and short trips whereas single birds or handicapped birds made several successive short trips and thereafter a long trip. In each treatment, food loads tended to be heavier after long trips than after short trips, and single birds tended to bring heavier loads than control or handicapped birds. Birds in the three treatments lost similar amounts of mass after short trips and gained similar amounts of mass after long trips. However, the mass of handicapped birds declined through the experiment, while that of control and single birds remained stable. Although the proportion of chicks that died during the experiment was similar among the three treatments, the chicks fledged by a single bird were lighter than those in control nests. The results of the experiment suggest that thin-billed prions adjust their breeding effort differently to decreased flying ability or increased food demand by the chick. Single birds increase foraging effort without allowing their condition to deteriorate. Conversely, handicapped birds are unable to maintain their body condition while sustaining the chick at the same rate as control birds. It is suggested that in this long-lived seabird, adults probably adjust their breeding effort so that they do not incur the risk of an increased mortality, this risk being monitored by the body condition. 相似文献
115.
Connan O Tessier E Maro D Amouroux D Hébert D Rozet M Voiseux C Solier L 《Journal of environmental radioactivity》2008,99(7):1102-1110
This study presents an original work on measurements of stable and radioactive iodinated species in the Seine estuary (France), with estimates fluxes of volatile gaseous species from water to the atmosphere. Various iodinated compounds were identified in water and air in particular 131I in water, what is unusual. Concentrations and behaviour of iodinated elements in the Seine estuary seem similar to what has been observed in other European estuaries. MeI (Methyl Iodide) and Total Volatile Iodine (TVI) fluxes from water to air vary between 392 and 13949 pmol m(-2) d(-1) and between 1279 and 16484 pmol m(-2) d(-1), respectively. Water to air flux of TVI for the Seine river was estimated in the range 4-46 kg y(-1). Measurements of (131)I in water varying between 0.4 and 11.9 Bq m(-3). Fluxes of (131)I from water to atmosphere are in the range 2.4 x 10(5)-1.3 x 10(7)Bq y(-1), close to an annual discharge of (131)I by a nuclear reactor. 相似文献
116.
Thomas J. Olivier Carole Ober John Buettner-Janusch Donald Stone Sade 《Behavioral ecology and sociobiology》1981,8(4):279-285
Summary In rhesus monkey populations, animals related by descent to some female comprise a matriline or genealogy. Data on blood protein polymorphisms in the Cayo Santiago rhesus colony indicate that allele frequency variations among matrilines in social groups are large. These variations occur despite high levels of outbreeding. Computer simulation analyses indicate that pedigree or linear effect account for much of the observed genetic differentiation among genealogies. A sampling with correlation model in which genealogy sizes and average kinship levels are parameters predicts among matriline genetic differentiation. This study indicates that substantial genetic substructure is present within rhesus social groups. Our analyses also predict that large variances in allele frequencies should be common among social or trait groups based on kinship relationships. 相似文献
117.
Edel Pérez-López Tyler Wist Yesenia Rodríguez Mauricio Luna-Rodríguez Chrystel Y. Olivier 《Environment, Development and Sustainability》2018,20(4):1797-1805
Native corn in Mexico can be affected by maize bushy stunt disease (MBS), which can negatively impact maize-farming operations. Maize bushy stunt symptoms in native corn were linked to the presence of phytoplasmas through molecular analysis of symptomatic native corn plants in Mexico. These findings motivated a socioeconomic characterization and identification of the management strategies developed by the “subsistence farmers” of those communities to answer the questions: What elements of farming affect the presence of MBS disease in “subsistence farmers” fields? What do “subsistence farmers” know about MBS disease and the pathogen associated with MBS disease? How best can MBS disease be managed in small farming communities in Mexico? Through face-to-face interviews with growers and the corresponding analyses of their responses, we identified a widespread lack of knowledge about MBS disease, its causal agent and its vector(s). This study highlighted factors useful to guide future management decisions and education programs, as well as further research to transmit information about MBS disease among “subsistence farmers” in rural communities in Mexico. 相似文献
118.
This paper is a contribution to the emergy evaluation of systems involving recycling or reuse of waste. If waste exergy (its residual usefulness) is not negligible, wastes could serve as input to another process or be recycled. In cases of continuous waste recycle or reuse, what then is the role of emergy? Emergy is carried by matter and its value is shown to be the product of specific energy with mass flow rate and its transformity. This transformity (τ) given as the ratio of the total emergy input and the useful available energy in the product (exergy) is commonly calculated over a specific period of time (usually yearly) which makes transformity a time dependent factor. Assuming a process in which a part of the non-renewable input is an output (waste) from a previous system, for the waste to be reused, an emergy investment is needed. The transformity of the reused or recycled material should be calculated based on the pathway of the reused material at a certain time (T) which results in a specific transformity value (τ). In case of a second recycle of the same material that had undergone the previous recycle, the material pathway has a new time (T + T1) which results in a transformity value (τ1). Recycling flows as in the case of feedback is a dynamic process and as such the process introduces its own time period depending on its pathway which has to be considered in emergy evaluations. Through the inspiration of previous emergy studies, authors have tried to develop formulae which could be used in such cases of continuous recycling of material in this paper. The developed approach is then applied to a case study to give the reader a better understanding of the concept. As a result, a ‘factor’ is introduced which could be included on emergy evaluation tables to account for subsequent transformity changes in multiple recycling. This factor can be used to solve the difficulties in evaluating aggregated systems, serve as a correction factor to up-level such models keeping the correct evaluation and also solve problems of memory loss in emergy evaluation. The discussion deals with the questions; is it a pure mathematical paradox in the rules of emergy? Is it consistent with previous work? What were the previous solutions to avoid the cumulative problem in a reuse? What are the consequences? 相似文献
119.
Alecia J. Carter Olivier Pays Anne W. Goldizen 《Behavioral ecology and sociobiology》2009,64(2):237-245
The mean vigilance of animals in a group often decreases as their group size increases, yet nothing is known about whether
there is individual variability in this relationship in species that change group sizes frequently, such as those that exhibit
fission–fusion social systems. We investigated variability in the relationship between group size and vigilance in the eastern
grey kangaroo (Macropus giganteus) by testing whether all individuals showed decreased vigilance with increased group size, as has been commonly assumed. We
carried out both behavioural observations of entire groups of kangaroos and focal observations of individually recognised
wild female kangaroos. As in other studies, we found a collective group-size effect on vigilance; however, individuals varied
in their vigilance patterns. The majority (57%) of the identified individual kangaroos did not show significant group-size
effects for any of the recorded measures of vigilance. The females that did not show a negative group-size effect were, on
average, more vigilant than those females that did show a group-size effect, but this difference was not significant. We propose
that some females exhibit higher levels of social vigilance than others, and that this social vigilance increases with group
size, cancelling out any group-size effect on anti-predator vigilance for those females. Our results therefore suggest that
only some prey individuals may gain anti-predator benefits by reducing their time spent scanning when in larger groups. The
large amount of variation that we found in the vigilance behaviour of individual kangaroos highlights the importance of collecting
and analysing vigilance data at the individual level, which requires individual recognition. 相似文献
120.
Olivier Didur David Dewez Radovan Popovic 《Environmental science and pollution research international》2013,20(3):1870-1875
The inhibitory effect of chromium (Cr) on photosystem II (PSII) activity was investigated in the green alga Chlamydomonas reinhardtii during different phases of the cell cycle. Algae were cultivated in continuous light or a light/dark cycle (16:8 h) to obtain a synchronously dividing cell culture. The cell division phases were determined with the DNA-specific fluorescent probe SYBR green using flow cytometry. The effect of Cr on PSII activity was investigated after a 24-h treatment with algal cultures having different proportions of newly divided cells (G0/G1), dividing cells at the DNA replication phase (S), and dividing cells at the mitosis phase (G2/M). Using chlorophyll a fluorescence parameters based on PSII electron transport capacity in dark- (ΦMII) and light-adapted (Φ′MII) equilibrium state, we found that the effect of Cr differs depending on the stage of the cell cycle. When algal cultures had a high proportion of cells actively dividing (M phase), the toxic effect of Cr on PSII activity appeared to be much higher and PSII quantum yield was decreased by 80 % compared to algal cultures mainly in the G0/G1 phase. Therefore, the inhibitory effect of Cr on photosynthesis appears to be different according to the cell cycle state of the algal population. 相似文献