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951.
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A gall midge pollinating flowers of Kadsura longipedunculata is described as Resseliella kadsurae sp. nov. based on adult specimens collected in 2006 from Langshan, Xinning County, Hunan Province, China. The new species is distinguishable from other known congeners in the combination of the following characteristics: gynecoid male flagellomeres, mottled wings, simple claws on all legs; male hypoproct with a transverse bridge‐like structure ventrally connecting both sides of hypoproct. In particular, the gynecoid male flagellomeres and transverse bridge‐like structure are unique to the new species. Partial sequencing of the cytochrome oxidase subunit I mitochondrial gene indicates that R. kadsurae is grouped with the R. theobardi + R. yagoi clade, but this clade and the monophyly of the genus Resseliella are not statistically supported. The new species is nocturnal, and mating occurs at dusk. At the time of mating, males and females hang on opposite sides of non‐sticky old spider webs in a venter‐to‐venter position. Immature stages and the life history of R. kadsurae are unknown. The flower‐visiting habit of R. kadsurae is contrasted with that of other flower‐visiting gall midges and the probability that this behavior exists in other congeners is discussed. 相似文献
954.
Anita Aisenberg Natalia Estramil Carlos Toscano-Gadea Macarena González 《Journal of Ethology》2009,27(1):43-50
Males can change their copulatory or sperm transfer patterns in response to sperm competition risk. Schizocosa malitiosa performs long copulations, which include two consecutive patterns (Patterns 1 and 2). Virgin females are very sexually receptive,
but mated females diminish their receptiveness. Female unreceptivity has been attributed to the action of receptivity-inhibiting
substances, mainly transferred during Pattern 1. We tested: (1) if females who mated only with Pattern 1 were immediately
unreceptive; (2) male and female behaviours when the copulating couple was exposed to another male. For (1), we interrupted
mating when Pattern 1 finished and immediately exposed the female to a second male. For (2), we introduced a second male when
the couple was starting (Ei) or finishing copulation (Li). Females were unreceptive immediately after finishing Pattern 1.
Males from Ei and Li dismounted and approached the second males. Ei males diminished the frequencies of insertion after perceiving
the presence of a second male and dismounted less frequently when copulating with heavy females. The study provides insights
about the timing of sexual unreceptivity in S. malitiosa under possibilities of sperm competition, discussing male adjustment of copulatory behaviour in the presence of rival males.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Douglass H. Morse 《Oecologia》1999,120(2):252-257
Earlier experiences may play an important role in the choice of hunting sites, but their effects on the foraging repertoire
of most animals remain poorly understood. I tested the role of previous flower choices (hunting sites) by penultimate-instar
female crab spiders Misumena vatia in making subsequent patch-choice decisions. M. vatia is a sit-and-wait predator, and the two flower species used, ox-eye daisy Chrysanthemum leucanthemum and common buttercup Ranunculus acris, are important hunting sites. Spiders with different immediate experience showed similar short-term (<1 day) giving-up times
on the two flower species, independent of their previous substrate. However, four-fifths of the individuals that remained
a day or longer tended to leave buttercups sooner than daisies, especially if they had previously occupied daisies. Thus they
may directly assess the quality of a potential hunting site, perhaps in response to prey abundance, but previous experience
may play a minor role as well. Of spiders that made several consecutive choices of hunting sites, those on daisies often confined
these runs to daisies (one of two years); those on buttercups did not exhibit comparable fidelity. Spiders molting into the
adult stage almost always subsequently chose the same flower species (either daisy or buttercup) as the one on which they
molted. Thus, juvenile experiences may influence adults, the critical stage when virtually all of the spiders' reproductive
resources are gathered, even if this resulted from imprinting on their molt sites rather than carrying information over the
molt.
Received: 26 December 1998 / Accepted: 21 April 1999 相似文献
959.
Marina Wirth Jonas O. Wolff Esther Appel Stanislav N. Gorb 《Journal of morphology》2019,280(4):534-543
Spiders attach silken threads to substrates by means of glue-coated nanofibers (piriform silk), spun into disc-like structures. The organization and ultrastructure of this nano-composite silk are largely unknown, despite their implications for the biomechanical function and material properties of thread anchorages. In this work, the ultrastructure of silken attachment discs was studied in representatives of four spider families with Transmission Electron Microscopy to facilitate a mechanistic understanding of piriform silk function across spiders. Based on previous findings from comparative studies of piriform silk gland morphology, we hypothesized that the fibre-glue proportion of piriform silk differs in different spiders, while the composition of fibre and glue fractions is consistent. Results confirmed large differences in the relative proportion of glue with low amounts in the orb weaver Nephila senegalensis (Araneidae) and the hunting spider Cupiennius salei (Ctenidae), larger amounts in the cobweb spider Parasteatoda tepidariorum (Theridiidae) and a complete reduction of the fibrous component in the haplogyne spider Pholcus phalangioides (Pholcidae). We rejected our hypothesis that glue ultrastructure is consistent. The glue is a colloid with polymeric and fluid fractions that strongly differ in proportions and assembly. We further confirmed that in all species studied both dragline and piriform silk fibres do not make contact with the environmental substrate. Instead, adhesion is established by a thin dense skin layer of the piriform glue. These results advance our understanding of piriform silk function and the interspecific variation of its properties, which is significant for spider biology, web function and the bioengineering of silk. 相似文献
960.
Tadashi Miyashita 《Population Ecology》1992,34(1):15-28
Mean daily food consumption and total lifetime food consumption of the spider, Nephila clavata, were estimated in natural populations. Daily food consumption in the late adult stage was 27–150 mg wet weight, which was nearly equivalent or slightly larger than that in other large web-building spiders. Considerable variation in food consumption was found among habitats or years. The largest variation among habitats in the same year was 7 and 5 fold for daily and lifetime consumption, respectively, while that among years in the same habitat was 3.5 and 2.5 for daily and lifetime consumption, respectively. Feeding conditions evaluated from the food consumption per body weight of spiders declined during the period from mid-July to mid-September in almost all the populations, which suggested that they faced to severe food limitation in this period. 相似文献