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131.
Kin selection and inclusive fitness theories predict that, in hopeless queenless (QL) groups, competition or cooperation will occur over male production among workers of different patrilines. Competition is expected to involve mutual inhibition of reproduction and to affect fertility advertisement. To examine kin effect on these phenomena, we studied QL groups of honeybee workers comprising three types of kin structure: groups composed of pure single patrilines, groups composed of three mixed patrilines (all originating from colonies headed by single-drone-inseminated queens), and control groups composed of bees originating from naturally mated queens. Global assessment of ovarian development, irrespective of patriline composition, revealed no differences among group types. In contrast, the performance of specific patrilines revealed that, in the three-mixed-patriline groups, some patrilines were reproductively suppressed compared to their performance when reared as a pure single patriline, resulting in an uneven share of reproduction. Analysis of the fertility signal produced by Dufour's gland revealed kin composition effects, which may reflect the bees' competitive efforts. Although patriline effects on worker reproductive superiority have been shown in QL colonies, we were able to investigate specific patriline performance both in competitive and noncompetitive situations here for the first time. The results are consistent with the hypothesis that reproductive and pheromonal competitions in QL groups are affected by the number of subfamilies populating a colony and that these act as coalitions. The results also emphasize that within-colony heterogeneity, in the form of multiple patrilines, has far-reaching consequences on social evolution. 相似文献
132.
Caste-specific pheromone biosynthesis is a prerequisite for reproductive skew in the honeybee. Nonetheless, this process is
not hardwired but plastic, in that egg-laying workers produce a queen-like pheromone. Studies with Dufour’s gland pheromone
revealed that, in vivo, workers’ gland biosynthesis matches the social status of the worker, i.e., sterile workers showed
a worker-like pattern whereas fertile workers showed a queen-like pattern (production of the queen-specific esters). However,
when incubated in vitro, the gland spontaneously exhibits the queen-like pattern, irrespective of its original worker type,
prompting the notion that ester production in workers is under inhibitory control that is queen-dependent. We tested this
hypothesis by exposing queen or worker Dufour’s glands in vitro to brain extracts of queens, queenright (sterile) workers
and males. Unexpectedly, worker brain extracts activated the queen-like esters biosynthesis in workers’ Dufour’s gland. This
stimulation was gender-specific; queen or worker brains demonstrated a stimulatory activity, but male brains did not. Queen
gland could not be further stimulated. Bioassays with heated and filtered extracts indicate that the stimulatory brain factor
is below 3,000 Da. We suggest that pheromone production in Dufour’s gland is under dual, negative–positive control. Under
queenright conditions, the inhibitor is released and blocks ester biosynthesis, whereas under queenless conditions, the activator
is released, activating ester biosynthesis in the gland. This is consistent with the hypothesis that queenright workers are
unequivocally recognized as non-fertile, whereas queenless workers try to become “false queens” as part of the reproductive
competition. 相似文献
133.
Merav Vonshak Tamar Dayan Julien Foucaud Arnaud Estoup Abraham Hefetz 《Behavioral ecology and sociobiology》2009,63(11):1667-1677
The little fire ant, Wasmannia auropunctata, constitutes one clonal supercolony throughout Israel, providing an opportunity to examine the effects of genotype versus
environment on nestmate recognition. Intraspecific encounters among field-collected or among laboratory-maintained colonies
were nonaggressive, but encounters between freshly collected and laboratory-maintained colonies were highly aggressive. Analyses
of cuticular hydrocarbons revealed that freshly field-collected colonies had distinguishable profiles. Moreover, freshly collected
colonies had profiles disparate from those of the same colonies after 4 months in the laboratory. These results indicate a
strong interplay between genetic-based and environmentally based effects on the recognition cues. We propose that in the field
the ants’ diet breadth is broad and consequently the incorporation of diet-borne substances is insufficient to mask the genetically
determined cues. In the laboratory, however, the restricted diet promoted the incorporation of alien hydrocarbons at high
levels, thus altering the genetically based cues to the point of alienation. These results shed a new light on the mechanisms
by which environmental cues may affect label and/or template formation in ants.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献