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71.
JOHN DOUGLAS HUDSON 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1970,3(1):11-40
Hudson, J. D.: Algal limestones with pseudomorphs after gypsum from the Middle Jurassic of Scotland. Lethaia , Vol. 3, pp. 11–40. Oslo, January 15th, 1970.
Algal limestones from two horizons within the Great Estuarine Series of the Hebrides are described. That from the Mytilus Shales is a typically stromatolitic limestone formed by algal trapping and binding of micrite pellets. Calcite pseudomorphs after gypsum occur along some of the laminae. The limestones from the Lower Ostrea Beds include less regularly-stromatolitic types, and nodular algal limestones that contain tubes of calcified algae, notably Cayeuxia nodosa Anderson. The algal nodules also yield uncalcified tubes composed of organic material, that are comparable to recent Schizothrix. These algae form inter-growths similar to those recorded from the recent supratidal deposits of the Bahamas. The algal nodules are often coated with microtufa. Pellet- and spheru-lite-limestones are associated with the algae, and pseudomorphs after gypsum are again found. Isotopic data on the carbonate-carbon, and the palaeoecological implications of the algae and the pseudomorphs are discussed. 相似文献
Algal limestones from two horizons within the Great Estuarine Series of the Hebrides are described. That from the Mytilus Shales is a typically stromatolitic limestone formed by algal trapping and binding of micrite pellets. Calcite pseudomorphs after gypsum occur along some of the laminae. The limestones from the Lower Ostrea Beds include less regularly-stromatolitic types, and nodular algal limestones that contain tubes of calcified algae, notably Cayeuxia nodosa Anderson. The algal nodules also yield uncalcified tubes composed of organic material, that are comparable to recent Schizothrix. These algae form inter-growths similar to those recorded from the recent supratidal deposits of the Bahamas. The algal nodules are often coated with microtufa. Pellet- and spheru-lite-limestones are associated with the algae, and pseudomorphs after gypsum are again found. Isotopic data on the carbonate-carbon, and the palaeoecological implications of the algae and the pseudomorphs are discussed. 相似文献
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75.
MICHELLE SIMEONI DEBORAH A. DAWSON DOUGLAS J. ROSS NICOLAS CHLINE TERRY BURKE BEN J. HATCHWELL 《Molecular ecology resources》2007,7(6):1319-1322
We characterized 20 microsatellite loci in the long‐tailed tit, Aegithalos caudatus. Polymorphic loci were identified by testing 114 loci that had been originally isolated in other avian species. The loci were characterized in 23–163 unrelated long‐tailed tits from a British population and displayed between two and 42 alleles, with observed heterozygosity ranging between 0.09 and 0.97. 相似文献
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Satellite-marked waterfowl reveal migratory connection between H5N1 outbreak areas in China and Mongolia 总被引:1,自引:0,他引:1
DIANN J. PROSSER JOHN Y. TAKEKAWA SCOTT H. NEWMAN BAOPING YAN DAVID C. DOUGLAS YUANSHENG HOU ZHI XING DEHAI ZHANG TIANXIAN LI YONGDONG LI DELONG ZHAO WILLIAM M. PERRY & ERIC C. PALM 《Ibis》2009,151(3):568-576
The role of wild birds in the spread of highly pathogenic avian influenza H5N1 has been greatly debated and remains an unresolved question. However, analyses to determine involvement of wild birds have been hindered by the lack of basic information on their movements in central Asia. Thus, we initiated a programme to document migrations of waterfowl in Asian flyways to inform hypotheses of H5N1 transmission. As part of this work, we studied migration of waterfowl from Qinghai Lake, China, site of the 2005 H5N1 outbreak in wild birds. We examined the null hypothesis that no direct migratory connection existed between Qinghai Lake and H5N1 outbreak areas in central Mongolia, as suggested by some H5N1 phylogeny studies. We captured individuals in 2007 from two of the species that died in the Qinghai Lake outbreaks and marked them with GPS satellite transmitters: Bar-headed Geese Anser indicus ( n = 14) and Ruddy Shelduck Tadorna ferruginea ( n = 11). Three of 25 marked birds (one Goose and two Shelducks) migrated to breeding grounds near H5N1 outbreak areas in Mongolia. Our results describe a previously unknown migratory link between the two regions and offer new critical information on migratory movements in the region. 相似文献
78.
WADE A. WALL NORMAN A. DOUGLAS QIU‐YUN XIANG WILLIAM A. HOFFMANN THOMAS R. WENTWORTH MATTHEW G. HOHMANN 《Molecular ecology》2010,19(19):4302-4314
The general phylogeographical paradigm for eastern North America (ENA) is that many plant and animal species retreated into southern refugia during the last glacial period, then expanded northward after the last glacial maximum (LGM). However, some taxa of the Gulf and Atlantic Coastal Plain (GACP) demonstrate complex yet recurrent distributional patterns that cannot be explained by this model. For example, eight co‐occurring endemic plant taxa with ranges from New York to South Carolina exhibit a large disjunction separating northern and southern populations by >300 km. Pyxidanthera (Diapensiaceae), a plant genus that exhibits this pattern, consists of two taxa recognized as either species or varieties. We investigated the taxonomy and phylogeography of Pyxidanthera using morphological data, cpDNA sequences, and amplified fragment length polymorphism markers. Morphological characters thought to be important in distinguishing Pyxidanthera barbulata and P. brevifolia demonstrate substantial overlap with no clear discontinuities. Genetic differentiation is minimal and diversity estimates for northern and southern populations of Pxyidanthera are similar, with no decrease in rare alleles in northern populations. In addition, the northern populations harbour several unique cpDNA haplotypes. Pyxidanthera appears to consist of one morphologically variable species that persisted in or near its present range at least through the latter Pleistocene, while the vicariance of the northern and southern populations may be comparatively recent. This work demonstrates that the refugial paradigm is not always appropriate and GACP endemic plants, in particular, may exhibit phylogeographical patterns qualitatively different from those of other ENA plant species. 相似文献
79.
新疆艾比湖湿地自然保护区鸟类清单及秋季迁徙数量统计 总被引:1,自引:1,他引:0
新疆物种多样性项目组在近10年中多次考察丁艾比湖区(44°50'N,82°50'E,海拔189 m).特别是2007~2009年逐月环湖考察,包括阿拉山口、奎屯河、精河、博尔塔拉河、科克巴斯陶、桑德库木、甘家湖、古尔图等,东西长118 km,南北宽56 km,覆盖6608 km2.采用样线法和点计数法对艾比湖区不同区域鸟的种类和数量进行统计和分析.记录到233种鸟类,是全疆种数的55%,分别隶属于17目53科128属.秋季一次统计到103 875只鸟类.首次发现了卷羽鹈鹕Pelecanus crispus、白头硬尾鸭Oxyura leucocephala、遗鸥Larus relictus和细嘴鸥Larus genei等的聚集地.另有夜鹭、小白额雁、斑背潜鸭、长尾鸭、剑鹆、小滨鹬、细嘴鸥、黄腹鹨等8种为新疆新纪录种.区系以占北种(183种,78.5%)和广布种(49种,21.0%)为主,极少东洋种.艾比湖为中哑鸟类迁徙的重要驿站. 相似文献
80.
We identified four new polymorphic microsatellite loci in bluefin killifish (Lucania goodei) and five loci in yellow bullheads (Ameiurus natalis). We screened 400 killifish from 20 populations and 180 bullheads from nine populations, finding a high degree of polymorphism (nine to 54 alleles per locus; average expected heterozygosity 0.678–0.976). We found no evidence for linkage disequilibrium. Three of the loci found in bluefin killifish show heterozygote deficiency; the other loci do not deviate from Hardy–Weinberg expectations. 相似文献