全文获取类型
收费全文 | 780篇 |
免费 | 6篇 |
国内免费 | 18篇 |
专业分类
安全科学 | 14篇 |
废物处理 | 8篇 |
环保管理 | 46篇 |
综合类 | 322篇 |
基础理论 | 195篇 |
环境理论 | 2篇 |
污染及防治 | 163篇 |
评价与监测 | 29篇 |
社会与环境 | 24篇 |
灾害及防治 | 1篇 |
出版年
2018年 | 10篇 |
2017年 | 13篇 |
2016年 | 16篇 |
2015年 | 17篇 |
2014年 | 12篇 |
2013年 | 35篇 |
2012年 | 27篇 |
2011年 | 33篇 |
2010年 | 22篇 |
2009年 | 26篇 |
2008年 | 25篇 |
2007年 | 27篇 |
2006年 | 39篇 |
2005年 | 25篇 |
2004年 | 15篇 |
2003年 | 21篇 |
2002年 | 20篇 |
2001年 | 12篇 |
2000年 | 8篇 |
1999年 | 27篇 |
1998年 | 13篇 |
1997年 | 11篇 |
1996年 | 14篇 |
1995年 | 7篇 |
1994年 | 13篇 |
1993年 | 8篇 |
1991年 | 6篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1985年 | 10篇 |
1983年 | 8篇 |
1970年 | 6篇 |
1967年 | 8篇 |
1966年 | 9篇 |
1965年 | 10篇 |
1964年 | 14篇 |
1963年 | 10篇 |
1962年 | 9篇 |
1961年 | 8篇 |
1960年 | 9篇 |
1958年 | 7篇 |
1957年 | 9篇 |
1956年 | 7篇 |
1955年 | 8篇 |
1954年 | 11篇 |
1953年 | 8篇 |
1952年 | 5篇 |
1939年 | 6篇 |
1931年 | 5篇 |
排序方式: 共有804条查询结果,搜索用时 234 毫秒
611.
Klaus Peschke Peter Friedrich Uwe Kaiser Stephan Franke Wittko Francke 《Chemoecology》1999,9(2):47-54
Summary. In the rove beetle Aleochara curtula, a male specific sternal gland is described. Isopropyl (Z9)-hexadecenoate has been identified by GC/MS of surface and sternal gland extracts as a male specific compound. Its emission
in the air was demonstrated by closed-loopstripping-analyses. In field experiments, conspecific males and females were attracted
by the odor of carrion, caged males from laboratory cultures, and by the synthetic ester. Isopropyl (Z9)-hexadecenoate or live males, combined with fresh carrion attract more beetles than a fresh carcass alone. Isopropyl hexadecanoate
as a minor compound was not attractive. The term “aggregation” pheromone and the ecological significance of attracting females
to a fresh carcass allowing early copulation and egg-deposition are discussed.
Received 20 August 1998; accepted 15 January 1999. 相似文献
612.
Karl-Werner Schramm Petra Marth Alexander Wolf Klaus Hahn Konstantin Oxynos Johannes Schmitzer Antonius Kettrup 《Environmental Sciences Europe》1999,11(5):277-280
Measured partition coefficients (KLM/L) related to lipid-concentrations between the muscle (CML) and liver (CLL) tissue of two fish species (Abramis brama, Zoarces viviparus) exhibit nominal values of unity according the relationship KLM/L=CML/CLL=1 for persistent compounds such as highly chlorinated PCB and values above one for degradable compounds for example chlorinated cyclohexanes or DDT. The corresponding theory is presented. The relationship holds for samples for single fish as well as for pooled samples. 相似文献
613.
614.
615.
Angeborene Tagesperiodik bei Eidechsen 总被引:1,自引:0,他引:1
Klaus Hoffmann 《Die Naturwissenschaften》1957,44(12):359-360
616.
Plant-soil microorganism interactions: heritable relationship between plant genotype and associated soil microorganisms 总被引:3,自引:0,他引:3
Schweitzer JA Bailey JK Fischer DG LeRoy CJ Lonsdorf EV Whitham TG Hart SC 《Ecology》2008,89(3):773-781
Although soil microbial communities are known to play crucial roles in the cycling of nutrients in forest ecosystems and can vary by plant species, how microorganisms respond to the subtle gradients of plant genetic variation is just beginning to be appreciated. Using a model Populus system in a common garden with replicated clones of known genotypes, we evaluated microbial biomass and community composition as quantitative traits. Two main patterns emerged. (1) Plant genotype influenced microbial biomass nitrogen in soils under replicated genotypes of Populus angustifolia, F1, and backcross hybrids, but not P. fremontii. Genotype explained up to 78% of the variation in microbial biomass as indicated by broad-sense heritability estimates (i.e., clonal repeatability). A second estimate of microbial biomass (total phospholipid fatty acid) was more conservative and showed significant genotype effects in P. angustifolia and backcross hybrids. (2) Plant genotype significantly influenced microbial community composition, explaining up to 70% of the variation in community composition within P. angustifolia genotypes alone. These findings suggest that variation in above- and belowground traits of individual plant genotypes can alter soil microbial dynamics, and suggests that further investigations of the evolutionary implications of genetic feedbacks are warranted. 相似文献
617.
Kate Arnold Yvonne Pohlner Klaus Zuberbühler 《Behavioral ecology and sociobiology》2008,62(4):549-559
Some non-human primates produce acoustically distinct alarm calls to different predators, such as eagles or leopards. Recipients
respond to these calls as if they have seen the actual predator, which has led to the notion of functionally referential alarm
calls. However, in a previous study with free-ranging putty-nosed monkeys (Cercopithecus nictitans martini), we demonstrated that callers produced two acoustically distinct alarm calls to eagle shrieks and leopard growls, but both
alarm calls were given to both predators. We can think of two basic explanations for this surprising result, a methodological
and theoretical one. Firstly, acoustic predator models may not always be suitable to test alarm call behaviour in primates,
sometimes causing uncharacteristic behaviour. Secondly, referential alarm calling may not be a universal feature of primate
alarm call systems. Considering the methodological and theoretical importance of these possibilities, we conducted a follow-up
study using life-sized leopard, eagle, and human models on the same population and compared the resulting vocal responses
to those given to acoustic predator models. We compared the alarm call series given to each of these predator model types
and found a considerable degree of consistency suggesting that the mode of presentation did not affect anti-predator calling
strategies. However, evidence for audience effects on calling behaviour was inconclusive. While it appears that predator class
is reliably encoded by different call series types irrespective of the mode of presentation, observations of these same call
series given in non-predatory contexts indicate that predator class is unlikely to be the relevant organising principle underlying
the alarm-calling behaviour in this species. We conclude by offering an alternative, non-referential, account of the alarm-calling
system exhibited by this species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
618.
Josefine Norman Per-Erik Jansson Neda Farahbakhshazad Klaus Butterbach-Bahl Changsheng Li Leif Klemedtsson 《Ecological modelling》2008
The amount of nitrogen gases (N2O, NO and N2) emitted from forest soils depends on interactions between soil properties, climatic factors and soil management. To increase the understanding of nitrogen processes in soil ecosystems, two dynamic models, CoupModel (coupled heat and mass transfer model for soil–plant–atmosphere systems) and the denitrification–decomposition (DNDC) model were selected. Both are dynamic models with different submodels for soil, vegetation, hydrology and climate system. CoupModel has a higher degree of detail on soil physical and abiotic components, whereas the DNDC model contains details of microbiological processes involved in production of nitrogen gases. To improve the previous simple submodel of nitrogen emission in CoupModel, we included a submodel corresponding to the forest version of DNDC containing photosynthesis/evapotranspiration-nitrogen (PnET-N-DNDC model). 相似文献
619.
Klaus Peter Rippe 《Journal of Agricultural and Environmental Ethics》2000,12(1):71-80
In the public debate concerning novel foods, someconsumer groups claim a consumer right to have accessto certain kinds of food in the market. To discusssuch statements, the paper identifies the reasons thatmay justify liberal states to regulate food. Althoughit defends certain paternalistic activities, itfavours an autonomy-centred food policy. Autonomy andconsumer sovereignty require that certain conditionsare fulfilled. It may be argued that one suchcondition is that the consumer should have choices.Against this position, the paper defends the view thatliberty rights to choose are limited to areas whichare of great importance for personal identity and thegood life. Local decisions in the area of foodconsumption do not have such importance, though globalones may have it. But even if this were true,government activity to protect such liberties shouldbe limited to the guarantee of formal conditions forthe good life of persons. It is not a legitimate taskof the government to safeguard specific conceptions ofthe good life. 相似文献
620.