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21.
The recently described Gallophasma longipalpis from Earliest Eocene French amber is considered to be a key fossil taxon that phylogenetically links ‘Mesozoic Phasmatodea’ with extant stick and leaf insects. However, our re‐evaluation of the evidence provided for this placement reveals that Gallophasma does not possess any unambiguous synapomorphies with extant forms, e.g. neither with Euphasmatodea nor with the more inclusive Phasmatodea. The fusion of abdominal segment 1 with the metathoracic segment, a derived character state present in both Gallophasma and Euphasmatodea, shows fundamental structural differences, and cannot be homologized between both taxa. We argue that the presence of a well‐developed, externally visible ovipositor and four‐segmented cerci in Gallophasma can be interpreted only as plesiomorphic with regards to all extant Phasmatodea, or even to Phasmatodea plus its putative sister groups Embioptera or Orthoptera. Gallophasma does not belong to the stem lineage of recent Phasmatodea, and is referred to best as ‘lower Neoptera’ or Polyneoptera incertae sedis. Therefore, this fossil may be central to reconstructing the ground pattern of the aforementioned orthopteroid lineages, and to determining wing character polarity within Polyneoptera.  相似文献   
22.
The Lanceocercata are a clade of stick insects (Phasmatodea) that have undergone an impressive evolutionary radiation in Australia, New Caledonia, the Mascarene Islands and areas of the Pacific. Previous research showed that this clade also contained at least two of the nine New Zealand stick insect genera. We have constructed a phylogeny of the Lanceocercata using 2277 bp of mitochondrial and nuclear DNA sequence data to determine whether all nine New Zealand genera are indeed Lanceocercata and whether the New Zealand fauna is monophyletic. DNA sequence data were obtained from mitochondrial cytochrome oxidase subunits I and II and the nuclear large subunit ribosomal RNA and histone subunit 3. These data were subjected to Bayesian phylogenetic inference under a partitioned model and maximum parsimony. The resulting trees show that all the New Zealand genera are nested within a large New Caledonian radiation. The New Zealand genera do not form a monophyletic group, with the genus Spinotectarchus Salmon forming an independent lineage from the remaining eight genera. We analysed Lanceocercata apomorphies to confirm the molecular placement of the New Zealand genera and to identify characters that confirm the polyphyly of the fauna. Molecular dating analyses under a relaxed clock coupled with a Bayesian extension to dispersal‐vicariance analysis was used to reconstruct the biogeographical history for the Lanceocercata. These analyses show that Lanceocercata and their sister group, the Stephanacridini, probably diverged from their South American relatives, the Cladomorphinae, as a result of the separation of Australia, Antarctica and South America. The radiation of the New Caledonian and New Zealand clade began 41.06 million years ago (mya, 29.05–55.40 mya), which corresponds to a period of uplift in New Caledonia. The main New Zealand lineage and Spinotectarchus split from their New Caledonian sister groups 33.72 (23.9–45.62 mya) and 29.9 mya (19.79–41.16 mya) and began to radiate during the late Oligocene and early Miocene, probably in response to a reduction in land area and subsequent uplift in the late Oligocene and early Miocene. We discuss briefly shared host plant patterns between New Zealand and New Caledonia. Because Acrophylla sensu Brock & Hasenpusch is polyphyletic, we have removed Vetilia Stål from synonymy with Acrophylla Gray.  相似文献   
23.
Annual and seasonal variation in reproductive timing and performance were studied in a population of the Lesser Spotted Woodpecker Dendrocopos minor over 10 years in southern Sweden. The median laying date of the first egg varied by up to 17 days between years, being generally larger than the variation of laying dates within years. Neither clutch size, brood size in successful nests, fledging success in successful nests nor mean nestling weight differed significantly between years. There was no trend for mean clutch size to vary between early and late years. In spite of a more than threefold variation in population size, no reproductive variable demonstrated an apparent density-dependence. Within the season, clutch size declined steeply with increasing clutch initiation date, whereas fledging success and nesting success did not, leading to a trend in brood size almost identical to the trend in clutch size. The survival prospects of fledged young declined with increasing clutch initiation date, and it is argued that the clutch size laid is a strategic adjustment to laying date. Out of 124 breeding attempts, 34% did not produce fledged young. In 9% of the breeding attempts, pairs laid no eggs. At least 20% of the breeding attempts failed after egg-laying. The most common cause of breeding failure was loss of the breeding partner followed by nest abandonment (40% of the failures). Only 16–28% of the failures were due to predation on the nest. Most complete failures, and also partial losses from nests, occurred at the early breeding stages. It is argued that the early nestling phase may be a critical stage, which the woodpeckers adjust to coincide with the seasonal food peak, explaining the strikingly late breeding season compared with other non-migrant species.  相似文献   
24.
The heat‐ and odour‐producing genus Arum (Araceae) has interested scientists for centuries. This long‐term interest has allowed a deep knowledge of some complex processes, such as the physiology and dynamics of its characteristic lure‐and‐trap pollination system, to be built up. However, mainly because of its large distributional range and high degree of morphological variation, species' limits and relationships are still under discussion. Today, the genus comprises 28 species subdivided into two subgenera, two sections and six subsections. In this study, the phylogeny of the genus is inferred on the basis of four plastid regions, and the evolution of several morphological characters is investigated. Our phylogenetic hypothesis is not in agreement with the current infrageneric classification of the genus and challenges the monophyly of several species. This demonstrates the need for a new infrageneric classification based on characters reflecting the evolution of this enigmatic genus. To investigate the biogeography of Arum deeply, further spatiotemporal analyses were performed, addressing the importance of the Mediterranean basin in the diversification of Arum. Our results suggest that its centre of origin was the European–Aegean region, and that major diversification happened during the last 10 Myr. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163 , 14–32.  相似文献   
25.
Liao, T.Y. & Kullander, S.O. (2012). Phylogenetic significance of the kinethmoid‐associated Y‐shaped ligament and long intercostal ligaments in the Cypriniformes (Actinopterygii: Ostariophysi). —Zoologica Scripta, 42, 71–87. The phylogenetic significance of the Y‐shaped and long intercostal ligaments in the Cypriniformes is examined using character optimization in 184 species representing 20 non‐ostariophysan teleost species, five ostariophysan orders, seven cypriniform families and 14 cyprinid subfamilies. Character states were optimized on the phylogenetic trees of previous studies. Given the topology of Saitoh et al. (2011) , the Y‐shaped ligament, connecting the kinethmoid to the ethmoid complex, is shown to be a synapomorphy for the Cyprinidae, with reversals observed in the Cyprininae, Danioninae, Gobioninae and Psilorhynchinae. The condition of the Y‐shaped ligament is consistent within most subfamilies with a few exceptions. Despite the exceptions, the Y‐shaped ligament may be considered as a diagnostic character distinguishing cyprinid subfamilies with otherwise similar morphology, that is, the Danioninae and Opsariichthyinae. The long intercostal ligament, connecting five to eight ribs and ascending from the subdistal end of the fifth rib, is present in the Catostomidae and all cyprinid subfamilies, except for the Psilorhynchinae and two developmentally truncated genera, Danionella and Paedocypris. In addition to these two cypriniforme families, the long intercostal ligament is homoplastically present in some catfishes. Given the topology of Saitoh et al. (2011) , presence of the long intercostal ligament is a synapomorphy of Cyprinidae+Catostomidae. Some shorter ligaments are also present in the Cypriniformes and Chilodus gracilis (Characiformes), near the base of the anterior ribs and only occurring anterodorsally to the putative line of the long intercostal ligament even when it is absent.  相似文献   
26.
Stridsberg, Sven 1981 12 15: Apertural constrictions in some oncocerid cephalopods. Lethaia , Vol. 14, pp. 269–276. Oslo. ISSN 0024–1164.
In some oncocerid cephalopods the shape of the aperture, siphuncle and the general outline of the shell have long served as generic characters. The aperture is mostly elaborated into a certain number of sinuses which take their final shape only in the adult. Therefore, knowledge of the relative age of the animal is required. The last chamber may serve as an indicator of age. A last chamber smaller than the second last indicates a mature specimen. This is because continued growth would have caused the death of the animal as the buoyancy turned negative. Moreover, it is of great importance to study the growth lines along the peristome to observe whether growth has ceased or not. Growth variations have been compared with growth stages. Furthermore, a constricted or contracted aperture can only be determined on specimens with the shell still preserved. Functional parallels are drawn between the Aprychopsis operculum and the restricted aperture. * Cephalopoda, Oncorerida. aperture, ontogeny, growth lines, functional morphologv , Aptychopsis. Silurian, Gotland .  相似文献   
27.
28.
Endogenous auxin levels in the shoots of apple cv. Ingrid Marie (red mutant) treated with SADH (succinic acid-2,2-dimethylhydrazide) were measured. SADH was applied in aqueous solution at 12.5, 25 or 50 mM concentrations in June, 3 weeks after flowering. The defoliated shoot tips were analysed just before SADH spray and 7, 15, 30 and 60 days after spraying. Similar treatments had been made in earlier years. When analysed before the treatment of the year started, shoot extracts of control plants contained higher auxin level than those shoots which were to receive SADH treatment, indicating a residual effect of SADH treatmens during previous years. There was almost no auxin activity in the shoots analysed after 7, 15 and 30 days of SADH treatment. The control plants maintained a high level of auxin activity during this period. However, after 60 days of treatment, shoots treated with 25 or 50 mM exhibited higher auxin activity than control shoots. There appears to be no relationship between the SADH concentration and reduction in auxin activity in the shoots at early stages after treatment.  相似文献   
29.
Climate change has proven to affect various aspects of the migration of birds. In response to milder winters making the habitat more profitable and increasing the survival of residents, the migratory fraction of partially migratory populations has been predicted to decline. We studied the blue tit Parus caeruleus , a common partial migrant in southern Sweden. The numbers migrating at Falsterbo, a migratory passage site in SW Sweden, has increased during the last decades, in parallel with increasing winter and annual temperatures. Migration data from Falsterbo were compared with yearly indices of the size of the breeding population as estimated by the Swedish National Bird Monitoring Programme. Over the study period 1975–2004, also the breeding population has increased in size. The proportion of blue tits migrating each year did not change over the study period, or possibly even increased slightly, which is in contrast to how climate change has been predicted to influence populations containing both migratory and resident individuals. The most important factors determining the intensity of blue tit migration in a given year was the size of an important winter food source, the beech mast crop (more migrants at lower crops) and the size of the breeding population (more migrants at higher densities).  相似文献   
30.
Acaronia vultuosa sp.n. occurs in the Rio Orinoco and upper Rio Negro drainages. In the Rio Negro it overlaps slightly the range of its only congener, A. nassa (Heckel), from which it can be distinguished by (1) the lack of microbranchiospines on the first gill arch, (2) thc separate instead of coalesced anterior gill rakers on the first gill arch, and (3) the colour pattern, which includes a much larger midlateral blotch and a different pattern of dark markings on the head.  相似文献   
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