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491.
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
492.
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
493.
494.
495.
Angeborene Tagesperiodik bei Eidechsen 总被引:1,自引:0,他引:1
Klaus Hoffmann 《Die Naturwissenschaften》1957,44(12):359-360
496.
Anne?Marijke?SchelEmail author Klaus?Zuberbühler 《Behavioral ecology and sociobiology》2012,66(3):361-373
Dawn chorusing by guereza black-and-white colobus monkeys is one of the most impressive spectacles of African rainforests.
This vocal behaviour is highly contagious, travelling from one neighbouring group to the next, until a wide forest area is
covered by calling monkeys. Chorusing usually occurs up to 2 h before dawn, sometimes more than once, unless the preceding
night was cold and wet. We conducted a series of playback experiments, which showed that guerezas’ chorusing was difficult
to elicit experimentally, suggesting that callers took several variables into account before responding to other monkeys’
predawn calls. Acoustic analyses showed that morning calls were individually distinct, but we found no evidence that callers
took individual identity into account in their decision to participate in chorusing. The only way to reliably elicit chorusing
in our study area was to broadcast recordings of morning choruses for longer than 30 s and at a time when a chorus simultaneously
emerged in a distant part of the forest. 相似文献
497.
Azhar Abbas T.S. Amjath-Babu Harald Kächele Muhammad Usman Klaus Müller 《国际发展与全球生态学杂志》2016,23(1):98-111
South Asia faces increasing flooding risks due to climatic and socio-economic changes. Various measures have been adopted by the governments of the countries in this region. However, these measures are not adequate to protect the vulnerable communities from ever-increasing flood losses. This study assesses the policy and planning processes and flood-related scientific research in India, Pakistan and Bangladesh. Based on a systematic review, a comparison of the existing flood management systems of the three countries is undertaken, and a framework for sustainable flood management in the region is suggested. Insights from the literature show that Bangladesh has been able to develop an effective governance structure to address flood hazards, while Pakistan’s approach to flood management planning is found to be largely inadequate. This inadequacy is mainly attributed to missing links in policy formulation and planning processes, along with a lack of institutional coordination. The results of the literature analysis reveal poor support from scientific research focusing on flooding issues in the case of Pakistan, while Bangladesh and India seem to have benefited from research support in formulating their flood management strategies. Based on these findings, an alternative framework is suggested, emphasizing the need to enhance institutional linkages, community participation and evidence-based research. 相似文献
498.
It is frequently assumed that males have an almost unlimited reproductive capacity, while access to receptive females is typically
limiting. Consequently, sexual selection is expected to favor vigorous courtship behavior in males. If such behavior is associated
with non-trivial costs, ample current mating opportunities should be accompanied by a reduction in future mating vigor. To
test this hypothesis, three treatments differing in sex ratio were established using the tropical butterfly Bicyclus anynana: 50 males each were housed either with 0, 25, or 50 females. Mating trials involving the competition among males from each
treatment for a single virgin female were carried out on days 3, 9, and 15 after allocation to treatments. While there was
no difference on day 3, prior mating opportunity clearly reduced mating success on days 9 and 15, being lowest if identical
numbers of males and females were housed together. This finding suggests accumulating costs associated with high courtship
and/or mating activity. Further, older males were more active and initiated copulation earlier than the younger ones, consistent
with the residual reproductive value hypothesis. We found no evidence for a survival or fertility cost of mating. 相似文献
499.
500.
Mercury, cadmium and lead concentrations in different ecophysiological groups of earthworms in forest soils 总被引:1,自引:0,他引:1
Ernst G Zimmermann S Christie P Frey B 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):1304-1313
Bioaccumulation of Hg, Cd and Pb by eight ecophysiologically distinct earthworm species was studied in 27 polluted and uncontaminated forest soils. Lowest tissue concentrations of Hg and Cd occurred in epigeic Lumbricus rubellus and highest in endogeic Octolasion cyaneum. Soils dominated by Dendrodrilus rubidus possess a high potential of risk of Pb biomagnification for secondary predators. Bioconcentration factors (soil-earthworm) followed the sequence ranked Cd > Hg > Pb. Ordination plots of redundancy analysis were used to compare HM concentrations in earthworm tissues with soil, leaf litter and root concentrations and with soil pH and CEC. Different ecological categories of earthworms are exposed to Hg, Cd and Pb in the topsoil by atmospheric deposition and accumulate them in their bodies. Species differences in HM concentrations largely reflect differences in food selectivity and niche separation. 相似文献