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21.
Dinoflagellates, their cysts and Quaternary stratigraphy   总被引:1,自引:0,他引:1  
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22.
Poisson/gamma random field models for spatial statistics   总被引:6,自引:0,他引:6  
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23.
Abstract The adipokinetic hormone (AKH) of the large milkweed bug Oncopeltus fasciatus is isolated from an acidified methanolic extract of 200 corpora cardiaca, purified by single step reversed phase high‐performance liquid chromatography (HPLC) and N‐terminally deblocked using pyroglutamate aminopeptidase. The sequence is identified by Edman degradation and matrix assisted laser desorption/ionization‐time of flight mass spectroscopy as pGlu‐Leu‐Asn‐Phe‐Ser‐Pro‐Asn‐Trp amide. This structure is confirmed by chemical synthesis and coelution of native and synthetic peptide on HPLC. The AKH of O. fasciatus is identical to Tenmo‐HrTH, a member of the adipokinetic/red pigment‐concentrating hormone peptide family that had been isolated earlier from several tenebrionid beetles. Tenmo‐HrTH causes a significant rise in the concentration of haemolymph lipids when injected into adult male and female O. fasciatus, but displays no hyperglycaemic activity. There is no indication of the presence of other AKHs in O. fasciatus. The large milkweed bug represents the first member of the seed bugs (Lygaeidae) for which the endogenous AKH has been identified.  相似文献   
24.
We compared the assemblages of phyllostomid bats in three Neotropical rainforests with respect to species richness and assemblage structure and suggested a method to validate estimates of species richness for Neotropical bat assemblages based on mist-netting data. The fully inventoried bat assemblage at La Selva Biological Station (LS, 100 m elevation) in Costa Rica was used as a reference site to evaluate seven estimators of species richness. The Jackknife 2 method agreed best with the known bat species richness and thus was used to extrapolate species richness for an Amazonian bat assemblage (Tiputini Biodiversity Station; TBS, 200 m elevation) and an Andean premontane bat assemblage (Podocarpus National Park; BOM, 1000 m elevation) in Ecuador. Our results suggest that more than 100 bat species occur sympatrically at TBS and about 50 bat species coexist at BOM. TBS harbours one of the most species-rich bat assemblages known, including a highly diverse phyllostomid assemblage. Furthermore, we related assemblage structure to large-scale geographical patterns in floral diversity obtained from botanical literature. Assemblage structure of these three phyllostomid assemblages was influenced by differences in floral diversity at the three sites. At the Andean site, where understorey shrubs and epiphytes exhibit the highest diversity, the phyllostomid assemblage is mainly composed of understorey frugivores and nectarivorous species. By contrast, canopy frugivores are most abundant at the Amazonian site, coinciding with the high abundance of canopy fruiting trees. Assemblage patterns of other taxonomic groups also may reflect the geographical distribution patterns of floral elements in the Andean and Amazonian regions.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 617–629.  相似文献   
25.
A new species of Sarcinomyces , a melanized fungus with meristematic development, is described. On the basis of small subunit and internal transcribed sequence regions of ribosomal DNA sequencing, the new species was accommodated in the anamorph genus Sarcinomyces (Herpotrichiellaceae, Chaetothyriales) close to S. petricola .  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 373–380.  相似文献   
26.
We characterize eight polymorphic microsatellite loci for the San Esteban chuckwalla, Sauromalus varius, which are being used as markers in a study of the genetic results from a decade of captive breeding in this endangered species. Observed heterozygosity estimates for S. varius ranged from 0.00 to 0.30, whereas expected heterozygosity estimates ranged from 0.06 to 0.58.  相似文献   
27.
REX I. DE SILVA 《Ibis》1987,129(1):88-92
A mass mieration of Bridled Terns Sterna anaethetus has been observed periodically off the south western coast of Sri Lanka during the past several years (Hoffmann 1975, Phillips 1978) and it is now evident that the phenomenon is an annual occurrence A preliminary study was initiated in 1981 (De silva 1982) and the results encouraged the continuation of observations until late October 1984 Only those aspects of migration which were visible from land are dealt with here  相似文献   
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29.
ABSTRACT. Polyurethane substrates were anchored near the surface of 14 lakes in the northern tip of the lower peninsula of Michigan. I wo substrates were removed from each take and taken to the laboratory after 1, 3, 6, 15, and 21 days of exposure. At the laboratory, one substrate was used for determining the number of species of diatoms and the other for protozoa. A cluster analysis of the matrix of Jaccard's coefficients for all diatom samples from all lakes showed that virtually all samples from any given lake consistently clustered together. This indicates that, with respect to species occurrence, distinct and compositionally stable diatom assemblages formed on the substrates in fewer than 21 days. Analysis of all protozoan samples from all lakes did not show such clustering, however, and the correspondence of clusters for protozoan and diatom communities for the 14 lakes was not particularly good. This suggests that the link between the two groups at the species level is not particularly strong during the early phases of artificial substrate colonization.  相似文献   
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