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61.
Radka Storchová Jií Reif Michael W. Nachman 《Evolution; international journal of organic evolution》2010,64(2):456-471
Several lines of evidence suggest that the X chromosome plays a large role in intrinsic postzygotic isolation. The role of the Z chromosome in speciation is much less understood. To explore the role of the Z chromosome in reproductive isolation, we studied nucleotide variation in two closely related bird species, the Thrush Nightingale ( Luscinia luscinia ) and the Common Nightingale ( L. megarhynchos ). These species are isolated by incomplete prezygotic isolation and female hybrid sterility. We sequenced introns of four Z-linked and eight autosomal loci and analyzed patterns of polymorphism and divergence using a divergence-with-gene flow framework. Our results suggest that the nightingale species diverged approximately 1.8 Mya. We found strong evidence of gene flow after divergence in both directions, although more introgression occurred from L. megarhynchos into L. luscinia . Gene flow was significantly higher on the autosomes than on the Z chromosome. Our results support the idea that the Z chromosome plays an important role in intrinsic postzygotic isolation in birds, although it may also contribute to the evolution of prezygotic isolation through sexual selection. This highlights the similarities in the genetic basis of reproductive isolation between organisms with heterogametic males and organisms with heterogametic females during the early stages of speciation. 相似文献
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63.
The establishment of non-native species and the increase in atmospheric CO2, in combination, have the ability to alter current ecosystems. Previous studies have shown that invasive species tend to
respond more strongly to CO2 than natives, but these comparisons have been of different and unrelated species. To assess how response to CO2 might be related to invasiveness per se, we compared a native (Typha latifolia) with a congeneric invasive (Typha angustifolia), as well as their hybrid (T. × glauca). All three taxa are common components of wetland vegetation, often occurring in near monocultures. An open-top chamber experiment
was used to examine the effects of elevated and ambient CO2 concentrations on the three taxa. All three increased rhizome biomass by 40% in elevated CO2. Although the absolute increase did not differ among taxa, the invasive T. angustifolia had a much higher proportional response in biomass and photosynthetic rate (45 and 40% respectively). The weaker response
of the two larger taxa native T. latifolia (16 and 2%) and hybrid T. × glauca (−4% and −1%) was possibly driven by soil nutrient deficiency, such that they were not able to benefit from increased CO2. However, under low nutrients the smaller species T. angustifolia may become more a problematic invader in the future. 相似文献
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67.
Tomá Herben† Frantiek Krahulec Vra Hadincová Sylvie Pecháková Radka Wildová 《Journal of Ecology》2003,91(1):103-113
68.
69.
We demonstrate that zooplankton escape abilities are consistent with the composition of the zooplankton community in the Great
Lakes following the invasion of the visually preying invertebrate predator Bythotrephes longimanus. Escape abilities were analyzed by videotaping responses of free-swimming zooplankton to encounters with tethered Bythotrephes. Both maximum speed and maximum acceleration of the escape response were appreciably greater in Daphnia
mendotae and diaptomids, whose populations remained relatively unchanged, than those of Daphnia
retrocurva and Daphnia
pulicaria, whose populations greatly decreased after the Bythotrephes invasion. Maximum speed of all species was higher in the light than in complete darkness, likely due to a different level
of activity of Bythotrephes. Contrary to treatments with Bythotrephes, mean and maximum swimming speeds of all species were similar to each other and the same in light and dark in treatments
without Bythotrephes. This implies that the prey were responding to infochemicals produced by Bythotrephes. 相似文献
70.
Marc De Meyer Hélène Delatte Sunday Ekesi Kurt Jordaens Blanka Kalinová Aruna Manrakhan Maulid Mwatawala Gary Steck Joannes Van Cann Lucie Vaní?ková Radka B?ízová Massimiliano Virgilio 《ZooKeys》2015,(540):405-427
This paper reviews all information gathered from different disciplines and studies to resolve the species status within the Ceratitis FAR (Ceratitis
fasciventris, Ceratitis
anonae, Ceratitis
rosa) complex, a group of polyphagous fruit fly pest species (Diptera, Tephritidae) from Africa. It includes information on larval and adult morphology, wing morphometrics, cuticular hydrocarbons, pheromones, microsatellites, developmental physiology and geographic distribution. The general consensus is that the FAR complex comprises Ceratitis
anonae, two species within Ceratitis
rosa (so-called R1 and R2) and two putatitve species under Ceratitis
fasciventris. The information regarding the latter is, however, too limited to draw final conclusions on specific status. Evidence for this recognition is discussed with reference to publications providing further details. 相似文献