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51.
More than 40 logboats are known from the Czech Republic, and at least 20 are preserved in repositories or regional museums (seven in Moravia, 13 in Bohemia). Two further vessels remain in situ. Many logboats are known from neighbouring countries, but until recently vessels from the Czech Republic have not attracted the same research interest. Only five Czech vessels (two from Bohemia and three from Moravia) have been dated by absolute methods. Several more have been assigned tentative dates on the basis of context or close similarity to other dated vessels. This article presents a summary of current evidence. © 2009 The Author  相似文献   
52.
Under certain environmental conditions, post-depositional diagenetic loss of bone collagen can severely reduce the number of bones from a particular archaeological site that are suitable for stable isotopic analysis or radiocarbon dating. This study examined nearly 300 bones from 12 archaeological sites across southern England known to yield poor or variable preservation to try to identify one, or more, pre-screening technique(s) that would indicate suitable collagen preservation for radiocarbon dating. The most reliable method was shown to be the percent nitrogen (%N) of whole bone powder, which has an 84% chance of successfully predicting whether or not a bone will yield sufficient (i.e. >1% weight) collagen for dating.  相似文献   
53.
This paper presents new AMS radiocarbon dating results of six ungulate bones from the current excavation of Isturitz Cave, France, layer C 4c4. The assemblage from this layer exhibits a suite of traits closely aligned with the Early Aurignacian, but with some aspects that bear strong similarities with the Protoaurignacian, with possible in situ technological transformation. Accurate and precise dating of the late Middle Palaeolithic and the early Upper Palaeolithic periods is critical to our understanding of the possible relationship between final Neanderthals and early modern humans in Europe. As such, a rigorous set of sample selection and evaluation protocols was developed and used in this research. Among these, only cutmarked bones were selected and a total of 31 targets were made, giving a weighted average of 37,180 ± 420 BP for this assemblage and providing a terminus ante quem for the ornaments, decorated artefact and amber pendants beneath it. The implications and importance of these results to debates concerning the chronological relationship between the Châtelperronian, Protoaurignacian and Early Aurignacian and associated debates regarding hominin dispersal, interaction and the timing of technical and cultural innovations are discussed.  相似文献   
54.
A set of 104 independently dated archaeomagnetic directions was used to extend the U.S. Southwest reference curve back to 375 cal BC and to calculate isolated mean VGPs centered on 960 cal BC and 2390 cal BC. Prior to this study, most U.S. Southwest reference curves extended to only ca. AD 585. This study employed Sternberg’s moving window technique with variably sized windows, rather than fixed windows, to smooth the dataset into a continuous curve. The size of each averaging window was determined by the density of data captured by the window, such that each window had a minimum data density of 5.0 and a minimum window size of 50 years. This approach differs from previous studies in the U.S. Southwest, which have applied a uniformly sized averaging window to a dataset regardless of the temporal distribution of the data.  相似文献   
55.
A new sedimentary morphogenic analysis was carried out at the Divje babe I Paleolithic site to determine paleotemperatures for Late Pleistocene deposits (around 80,000–40,000 BP) and to discover hiatuses in the sedimentary sequence. The Divje babe I paleotemperature record is based on the relative abundance of congelifracts in a 280 cm thick sedimentary sequence. Congelifracts are clasts whose morphogenesis is directly associated with post-depositional frost wedging. The Divje babe I paleotemperature record compares well with global GRIP (Summit) and other regional paleotemperature records for the Late Pleistocene. Comparisons are supported by ESR dates from the Divje babe I site. Two significantly cool climate phases were identified in the Divje babe I record. The older cool phase was placed between 67,000 BP and 62,000 BP and the second, younger cool phase was placed between 61,000 BP and 58,000 BP (both Middle Würmian) according to correlations with the GRIP record. The main disadvantage with the Divje babe I paleotemperature record is missing data. The sequence of cave sediments is not complete in Divje babe I due to breaks in sedimentation. Two reliable and two assumed hiatuses were identified in the studied sedimentary sequence.  相似文献   
56.
2003年2月,云南省文物考古研究所为配合三峡工程建设,对位于重庆万州区武陵镇的中嘴遗址进行了考古发掘。本次发掘的遗存以隋唐时期为主,出土了陶器、瓷器以及其他遗物,从中透射出渔业活动是当时当地居民生产生活的一个重要方面,同时也可看到当地文化与周边文化的交流。  相似文献   
57.
The Aterian has a huge geographic extension covering all North Africa, although it was not supposed to exist in the mountain ranges of the central Sahara. Its chronological context is not yet definitively determined and it is still difficult to say whether the Aterian tools are technological, typological, functional, or chronological markers. Recent surveys and excavations at Uan Tabu and Uan Afuda, two rock-shelters located in the central Tadrart Acacus, provide the first chronological, environmental and archaeological indications on this Late Pleistocene human occupation in the area. The lack of organic matter led us to perform OSL and TL analyses on sand. L'Atérien a une énorme extension géographique qui couvre tout le Nord de l'Afrique, tandis qu'on ne pensait pas qu'il existait dans les montagnes du Sahara central. Son contexte culturel n'est pas définitivement déterminé et il est encore difficile de dire si les instruments atériens sont des indicateurs téchnologiques, typologiques, fonctionels ou culturels. Reconnaissances et fouilles récentes à Uan Tabu et Uan Afuda, deux abris situés dans l'Acacous central, fournissent les premières indications sur la chronologie, l'environnement et l'archéologie de l'Atérien dans la région. L'absence de la substance organique, nous a porté à faire des déterminations OSL et TL sur les sables.  相似文献   
58.
Two significant events in the late Holocene history of Madagascar were (a) the arrival of people, and (b) the loss of nearly two dozen species of land vertebrates in the socalled “subfossil extinctions”. The consensus is that the faunal losses occurred shortly subsequent to human arrival, but the timing of these events is poorly constrained. The minimum age for initial human presence on the island may now be set at approximately 2000 bp, on the basis of AMS 14C dates for human-modified femora of extinct dwarf hippos from SW Madagascar. Assuming that this date also marks the beginning of deleterious human interactions with the subfossil fauna, and assuming that this fauna became completely extinct by 900 bp, the width of the anthropogenic “extinction window” may have been as long as c. 1000 a. This estimate, nearly twice the length of previous ones, is close to the unadjusted minimum for the duration of the terminal Pleistocene extinction event in the Americas. Whether or not this length of time comports with theoretical expectations of a “blitzkrieg” pattern of losses is uncertain, but greater refinement in dating the end of the subfossil extinctions is unlikely to produce radically shorter estimates of duration.  相似文献   
59.
This study uses quartz-based optically stimulated luminescence dating to determine when a massive fortification wall (W11186) was constructed in the archaeological site of Tall Zarʿa in the Jordan Valley. A total of 11 samples of sediments were taken from a trench on the north side of the wall (extramuros). The extracted quartz grains had good luminescence characteristics and were identified as well bleached by comparison with feldspar infrared-stimulated luminescence (IRSL) ages. The optical ages showed that the deposition against the wall occurred in two different periods. The first was around 3.20 ± 0.07 ka ago (Iron Age), and the second was around 2.28 ± 0.08 ka (Hellenistic period). Human activity was evident because of the intermixing of cultural material with the presumed naturally deposited units.  相似文献   
60.
夏商周断代工程采用系列样品进行14C年代测定,得出了夏商西周的年代框架,与考古遗址相对应,解决了三代考古学的分期.登封王城岗古城约为公元前2070年,即夏的起始年代.偃师商城始建于公元前1600年,郑州商城始建于公元前1580年,前者早于后者,偃师商城遂成为夏商分界的界标.就作为都城而言,郑州商城开始作为王都的时间比起偃师商城开始作为王都的时间要晚得更多.  相似文献   
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