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松辽盆地白垩纪微体生物群分布特征与富烃源岩层的形成 总被引:3,自引:0,他引:3
松辽盆地是我国白垩纪最大的陆相含油气盆地,晚白垩世两次大的湖侵事件导致了微体生物群的繁盛和富烃源岩层的形成。在论述松辽盆地白垩纪微体古生物群分布特征的基础上,着重阐述了以微体生物为核心的松花江生物群的发育与富烃源岩层形成的关系。认为大型富营养湖泊的发育为松花江生物群的繁盛创造了良好的外部条件,而湖盆内繁盛的微体生物群则为富烃源岩层的形成提供了丰厚的物质基础,与此同时,长期继承性深水构造凹陷和非补偿沉积则是富烃源岩层形成的有利场所。 相似文献
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Johnson RW Ahmed TF Miesbauer LJ Edalji R Smith R Harlan J Dorwin S Walter K Holzman T 《Analytical biochemistry》2005,341(1):22-32
Fragmentation and "top-down" sequencing of intact proteins by mass spectrometry (MS) is most commonly performed by infusion of protein solutions into Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers. However, the high cost of this instrumentation, coupled with the need to infuse "clean" solutions (lacking standard biological buffers), limits broad application of this technique. The current study describes an alternative approach to top-down sequencing using in-source fragmentation on quadrupole time-of-flight (Q-Tof) instrumentation coupled with reversed-phase liquid chromatography (LC). Application of this technique to purified recombinant samples yielded protein fragments during routine LC-MS analysis. The presence of multiple N- and C-terminal fragments allowed localization of structural modifications without proteolytic digestion. The method was extended to complex samples by using LC conditions that provided high-resolution protein separation. Utility of the method was illustrated by real-time monitoring of protein modifications occurring in reconstituted apoptosomes. These experiments illustrate that intact protein mass and limited sequence information can be obtained simultaneously on an LC timescale. This approach will allow a wide variety of laboratories to routinely apply top-down sequencing to problems in structural characterization, protein purification, and biomarker identification. 相似文献
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山西汾河源头地区种子植物区系地理成分分析 总被引:2,自引:0,他引:2
汾河源头地处山西吕梁山北段的管涔山系腹地,暖温带北部.据调查,汾河源头共有种子植物94科398属875种(含种下等级,下同),其中裸子植物3科7属12种,被子植物91科391属863种.种子植物科、属、种各类分布型占总数百分比没有明显的相关性,科、属、种的区系成分特有现象不平衡.科的分布区类型中,世界分布40科,温带分布30科,没有中国特有科;属的分布区类型中,温带分布264属,北温带成分处于显著地位,中国特有属4属,反映出该区植物区系的温带性质;种的分布区类型中,中国特有分布最多,共501种,其次是温带亚洲和东亚分布,成为构成汾河源头地区森林植被和灌从植被的建群种和优势种的主要成分. 相似文献
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Since natural and anthropogenic sources can contribute to elevated levels of metals at remote and background sites, identifying the source of a metal is an important step in environmental risk assessment. Various source apportionment procedures are available to identify metal sources, and have been used extensively to determine sources in urban settings and to a lesser extent at remote sites. However, measuring metals at remote or background sites presents unique challenges with respect to experimental design. The state of the science in monitoring techniques and source apportionment procedures is discussed in terms of limitations and applicability to remote sites, and recommendations are made on maximizing information recovery through source apportionment procedures by incorporating appropriate experimental design. 相似文献
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《Palaeoworld》2014,23(2):162-186
Site 549 of the Deep Sea Drilling Project was drilled on the Goban Spur in the Bay of Biscay in 1981. The core recovered from this North Atlantic location included 290 m of Barremian and possibly partly Hauterivian “syn-rift” deposits overlain unconformably by rocks of early Albian age. The number and variety of spores and pollen grains in the palynomorph assemblages and associated palynofacies through these units together with the presence of some pieces of wood, fragments of foliage, and a few megaspores in the lowest part of the Cretaceous succession suggest that the source area vegetation was, at least initially, relatively close to the site of deposition. Ginkgoalean, bennettitalean, and other gymnosperm groups are represented in the plant mesofossil assemblage but most of the fragments of foliage show cheirolepidiaceous characteristics. Five species belonging to this family have been identified and described. Two of these, Frenelopsis atlantica Zhou and Batten and Frenelopsis? alvinii Zhou and Batten, are new and one is unnamed. The composition of the three informally identified suites of spore and pollen assemblages recovered from 49 samples through the Early Cretaceous succession is consistent with age determinations of parts of it determined previously on the basis of dinoflagellate cysts, foraminifera, nannoplankton, and other fossils. 相似文献
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