全文获取类型
收费全文 | 1346篇 |
免费 | 60篇 |
出版年
2020年 | 11篇 |
2019年 | 19篇 |
2018年 | 28篇 |
2017年 | 21篇 |
2016年 | 38篇 |
2015年 | 26篇 |
2014年 | 29篇 |
2013年 | 437篇 |
2012年 | 60篇 |
2011年 | 54篇 |
2010年 | 48篇 |
2009年 | 55篇 |
2008年 | 26篇 |
2007年 | 47篇 |
2006年 | 56篇 |
2005年 | 18篇 |
2004年 | 23篇 |
2003年 | 22篇 |
2002年 | 19篇 |
2001年 | 24篇 |
2000年 | 18篇 |
1999年 | 11篇 |
1998年 | 15篇 |
1997年 | 7篇 |
1996年 | 12篇 |
1995年 | 15篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 9篇 |
1989年 | 11篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 8篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 14篇 |
1979年 | 12篇 |
1978年 | 9篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1974年 | 12篇 |
1973年 | 5篇 |
1972年 | 6篇 |
1971年 | 8篇 |
1968年 | 10篇 |
1967年 | 6篇 |
1966年 | 7篇 |
排序方式: 共有1406条查询结果,搜索用时 15 毫秒
151.
152.
A wooden Roman anchor was discovered at the retreating shore of the Dead Sea, north of Ein Gedi. The anchor's wood material was coated by a thick veneer of aragonite and gypsum crusts. The wood was dated by radiocarbon to the early Roman time in the Levant. Lead isotope analyses carried out on the Pb–Fe–Cu anchor material (remains of the anchor's metal parts) yielded ratios that indicate origin of the metal in Italian ores (maybe Tuscan). For the wooden part of the anchor a local tree was used. 相似文献
153.
Ruth M.K. Plets Justin K. Dix Jon R. Adams Jonathan M. Bull Timothy J. Henstock Martin Gutowski Angus I. Best 《Journal of archaeological science》2009
The remains of Henry V's flagship, the Grace Dieu, currently lie buried within the inter-tidal sediments of the River Hamble (S. England). Previous archaeological investigations have been hindered by difficult excavation conditions resulting in a poor understanding of the dimensions, shape and degradation state of the hull's deeper structure. This study therefore aimed to image, characterize and reconstruct the buried remains of this vessel using a high-resolution 3D acoustic sub-bottom Chirp system with RTK-GPS positioning capability. The accurate navigation and high-resolution data that were acquired enabled the construction of a full 3D image of the site that not only identified the remains of the wooden hull, but also features buried within it. In addition, the degradation state of these buried wooden remains were investigated by calculating reflection coefficients while a hypothetical larger reconstruction of the Grace Dieu's hull was achieved, through the use of the ShipShape ship design software package. 相似文献
154.
Kuhn's Geometric Index of Unifacial Stone Tool Reduction (GIUR): does it measure missing flake mass?
Kuhn's GIUR is a set of measurements taken on a resharpened stone flake's edge. Its purpose is to estimate the amount of stone removed before the exhausted tool was abandoned. An experimental test of Kuhn's Index led Hiscock and Clarkson to suggest that it is an excellent estimator of flake mass loss. Our own tests, using different experimental procedures, reached much less optimistic conclusions. Here, we apply their own measurement procedures, and successfully duplicate their results. It does not follow, however, that our now-consistently high correlations have a causal connection. As GIUR values increase, they are less able to estimate the actual loss of flake mass. It appears, therefore, that incremental loss of flake mass need not be the sole driver of the GIUR value. If the correlation is an inevitable byproduct of the experiment's design, as it now appears, then analyses based on this high correlation will be misleading. The GIUR remains, however, and excellent gauge of flake edge exhaustion. 相似文献
155.
A large systematic dye investigation of prehistoric Danish and Norwegian bog textiles was carried out using high performance liquid chromatography with photo diode array detection. After the selection of the most suitable protocol for dye extraction and HPLC analysis for this specific group of archaeological samples, the second part included the characterisation of the dyes detected in the whole series of the Early Iron Age textiles and the interpretation of the dyeing technology. Natural organic dyes were found from the three main categories of natural dyes, hence throwing new light on the use of biological dye sources in Early Iron Age Scandinavia. The results clearly indicate that most Scandinavian peat bog textiles originally were dyed and that already during the 1st millennium BC, the populations in Scandinavia were familiar with the dyeing technology. 相似文献
156.
Andrew I. Duff Jeremy M. Moss Thomas C. Windes John Kantner M. Steven Shackley 《Journal of archaeological science》2012
X-ray fluorescence analysis of obsidian artifacts from sites located in Chaco Canyon and from three Chaco-era communities in New Mexico permits determination of their geological origin. These source data are used to describe patterning in obsidian procurement in sites located in Chaco Canyon dating from A.D. 500–1150, and in a three non-Canyon communities occupied during the period of Chaco Canyon's regional prominence (ca. A.D. 875–1150). These data demonstrate that the most proximate sources generally dominate the sourced obsidian assemblages from sites of all periods, but also suggest differences in procurement patterning both over time and across space. Within Chaco Canyon, there is a notable shift from Mount Taylor obsidian to use of Jemez Mountains sources over time. These data also suggest that earlier analyses of obsidian from sites in Chaco Canyon misidentified some obsidian artifact sources; these new data indicate the central areas of disagreement and provide a revision of procurement patterning. In the Chaco-era communities located outside Chaco Canyon, procurement patterning diverges. The Blue J community shows an increase in use of the nearby Mount Taylor source over time. Two communities located toward the southern extent of the Chaco great house distribution reveal a markedly distinct procurement pattern, obtaining nearly all of their obsidian from southern sources largely unrepresented at Chaco Canyon. Combined, these data provide new insights into raw material procurement and artifact production at sites in Chaco Canyon, and in communities occupied during the Chaco Phenomenon, the period of the Canyon's greatest regional influence. 相似文献
157.
Charlotte L. Pearson Carol B. Griggs Peter I. Kuniholm Peter W. Brewer Tomasz Ważny LeAnn Canady 《Journal of archaeological science》2012
The 1st millennium AD was a time of great transition in Europe and the Mediterranean. At the heart of the Byzantine Empire, Constantinople (modern day Istanbul) was a pivotal trade hub for the Aegean region. Establishing a precise and accurate dating framework for the development of this remarkable city and a chronological reference for this critical time period for the Mediterranean region is of great importance to a wide range of scholars. Here we present a new 213 year tree-ring record from 89 oak samples placed in time by dendrochronology and supported by radiocarbon analysis and historical documentation. It represents the middle of the first millennium AD in Constantinople. The tree-ring series are derived from pilings recovered from the extraordinary excavations of the so-called “Theodosian harbor” at Yenikap?, Istanbul, along with timbers from other sites and buildings around the city, including one of the most famous sites on the Istanbul sky-line—Hagia Sophia. They provide potential for new insight into a time period in which earthquakes, the Justinianic plague, and even a possible tsunami struck the city, and during which dramatic changes in climate have been recorded in other paleoenvironmental proxies. The chronology is the first published tree-ring series from the Aegean region to cover the ‘event’ years of AD 536–7 and 542 which are characterized by anomalous growth in other tree-ring series from around the world, but interestingly these event years are not evident in this tree-ring sequence. 相似文献
158.
Ken Frank I‐Chien Chen Youngmi Lee Scott Kalafatis Tingqiao Chen Yun‐Jia Lo Maria Carmen Lemos 《政策研究杂志》2012,40(3):492-515
This study explores how a scientist's location in science‐based policy networks can affect her policy‐oriented behaviors. In particular, we hypothesize that those scientists who fill structural holes in their networks will be more likely than others to engage in policy‐oriented behaviors. The network data are defined by scientists' coauthorship on policy documents regarding climate change in the Great Lakes. We employ a two‐mode network analysis to identify clusters of scientists who coauthored similar documents, and relative to those clusters, we identify those who fill structural holes by bridging between clusters. We find that those scientists who bridged between clusters were more likely to engage in policy‐oriented behaviors of policy advocacy and advising than were others in the network. This is an example of a link between network location and policy‐oriented behavior indicative of the broader phenomenon of how individuals exert agency, given structural constraints. 相似文献
159.
This work describes the procedures, the different techniques and the pipeline used for creating a digital framework that should assist the Superintendence of Pompeii in the digital reconstruction, classification, management and visualisation of archaeological finds inside an advanced 3D web-based repository of reality-based data. Specific topics have been focused on the quality assessment procedures adopted to ensure consistency and reliability of data throughout the whole 3D models acquisition and pipeline creation, as well as on the particular semantic reality-based structure adopted to develop an information system into a knowledge one. The main purposes of our framework have been the usage of 3D digital models as a restitution of the real object and as a metaphor for navigating through the data; 3D models were used as archaeological cognitive systems and developed as a collection of structured objects, identified through a precise terminology that allows to easily extend the concept of 2D GIS to 3D GIS. In addition, the system was developed as a scalable application that allows the use of the same database by different users, simply filtering the data according to the specific requirements, and can operate both as standalone and web-based application. 相似文献
160.
In 2010 we have described in JAS a novel method for quantifying sickle gloss. Independently, Goodale et al. (2010) published another method for quantifying gloss based on a different method. Recently, the methods of both teams have been criticized by Stemp et al. We argue below that the critique is lacking and that the method we devised, laser He–Ne measurement, is a way to quantify sickle blade gloss that enables an objective estimate of the intensity of sickles use. The system is not expensive and is time efficient. 相似文献