首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1046篇
  免费   73篇
  1119篇
  2024年   6篇
  2023年   27篇
  2022年   8篇
  2021年   9篇
  2020年   49篇
  2019年   45篇
  2018年   125篇
  2017年   102篇
  2016年   90篇
  2015年   52篇
  2014年   60篇
  2013年   229篇
  2012年   39篇
  2011年   37篇
  2010年   42篇
  2009年   22篇
  2008年   29篇
  2007年   20篇
  2006年   12篇
  2005年   8篇
  2004年   12篇
  2003年   5篇
  2002年   9篇
  2001年   8篇
  2000年   8篇
  1999年   7篇
  1998年   10篇
  1997年   4篇
  1996年   3篇
  1995年   5篇
  1994年   4篇
  1993年   3篇
  1992年   3篇
  1991年   2篇
  1989年   4篇
  1988年   1篇
  1987年   3篇
  1986年   3篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
排序方式: 共有1119条查询结果,搜索用时 10 毫秒
71.
The original fineness of coins is very important information that can help us to understand the commercial situation in a wide historical context. This paper deals with a comparison of analytical methods suitable for the evaluation of the actual and original fineness of coins based on a detailed case study of a medieval coin sample. Both non‐destructive (i.e., scanning electron microscopy/energy‐dispersive X‐ray spectroscopy, X‐ray fluorescence, atomic force microscopy and hydrostatic weighing) and destructive (i.e., inductively coupled plasma – mass spectrometry and the Volhard titration method) techniques were used. The original fineness can be also deduced from knowledge of the internal structure of the coin (limited miscibility of copper and silver). A new analytical method based on a combination of a micrograph of the metallographic cross‐section with consequent image analysis was developed for determination of the original fineness. The proposed approach is relatively simple and provides reliable values. Sample heterogeneity and its impact on the determination of fineness are also discussed.  相似文献   
72.
The behavioural, cultural, and political implications of archaeological human remains in non‐mortuary, possibly culinary, contexts requires that we understand the range of mortuary practices in a particular region. Although several rockshelter sites on Mangaia, Cook Islands have yielded burned, fragmentary human bones in earth ovens that seem to support archaeological models and ethnohistoric accounts of ritual sacrifice and cannibalism, the absence of data on the range of Mangaian mortuary patterns obscures these interpretations. We describe burial patterns based on 40 above‐ground interments representing at least 92 individuals in caves of Mangaia, Cook Islands, in order to begin to develop an island‐wide perspective on mortuary patterns. Sampling both pre‐ and post‐European contact sites we found that multiple interments dominate probable pre‐contact burials (73%, 19 of 26) and single interments dominate post‐contact contexts (80%, eight of ten burials), probably reflecting the influence of Christianity on mortuary ritual. Subadults were more frequent in all post‐contact contexts suggesting alternative burial places, probably church cemeteries, for adults. Burial cave remains are broadly consistent with ethnohistoric accounts of interment in caves, however, they also illustrate additional burial practices and differences between time periods, such as primary body position and the role of multiple‐individual interments, which are not discussed ethnohistorically. The mortuary practices in Mangaian burial caves differ from burials associated with marae and seem completely unrelated to the presence of highly fragmentary and burnt human remains in pre‐contact rockshelter middens elsewhere on the island. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
73.
The lithic assemblage from the Middle Palaeolithic site of Payre (Rhone Valley, France) contains a large number of convergent tools and pointed tools of various shapes, sizes and retouch types. These were excavated from several archaeological units, dating from marine isotopic stages 8–5, which also yielded human skeletal remains. Consideration of this large tool kit has led to an improved analysis of Middle Palaeolithic tools with two retouched convergent edges. The 350 tools were not described within the classical typological framework, but, rather, from a lithic technological perspective in relation to a discoid debitage. In addition, an initial macroscopic use-wear analysis aided in establishing whether they were used according to their technical and/or morphological features. The Middle Palaeolithic convergent tools from Payre are shown to be quite diversified, and the question of the significance of the retouch and the definition of the various types is addressed. Initial functional results indicate that a clear relationship between shape and function cannot be easily established, and that these tools were used as hand tools. This study contributes to the debate on the use of stone tip spears in the Early European Middle Palaeolithic.  相似文献   
74.
This paper analyses social transformations in the Early Iron Age based on a holistic and longue durée approach applied to the first fortified habitats in the Iberian north-west. Through a comprehensive review of two paradigmatic settlements of the EIA in the province of A Coruña (Galicia, north-west Iberia), Punta de Muros and A Graña, a comparison is drawn between the social and territorial dynamics of this period by means of an in-depth analysis of the main characteristics of both settlements. Accordingly, a greater level of social complexity during the phases of occupation of the settlement of Punta de Muros has been identified, in contrast to the resistance to change observed in A Graña. Based on these conclusions, the role of metalworking and its symbolic value in fostering and legitimizing these social and territorial transformations and in the development of Iron Age communities are analysed.  相似文献   
75.
Research into the family of the Counts Swéerts-Sporck raised doubts regarding their biographical data, particularly concerning a child who died in 1817, later identified as Philipp Swéerts-Sporck, and his siblings Joseph and Barbara. These were alleged to include a pair of dizygotic twins, but DNA could not be used to clarify their relationships. Carbon and nitrogen isotopes were therefore measured in their first permanent molars, whereas Philipp's biological age was estimated based on his skeleton. Philipp died at an older age than the written sources claim; an isotopic similarity was found between Joseph and Barbara, but Philipp differed.  相似文献   
76.
During colonial times, an active maritime trade existed between Spain and the New World, with convoys sailing annually to and from Mexico and returning via Havana, Cuba, after wintering in America. A database constructed from secondary and open sources revealed that Spanish vessels were sailing over open waters along a northern path near Louisiana and a southern path across the central Gulf of Mexico. These routes were traversed in about one month and scheduling for the convoy was based on an understanding of the Americas’ meteorological and oceanographic climate. However, other factors may also have been involved in the directional layout of the routes. Today these ancient routes crisscross planning areas for oil and gas lease sales in the US Exclusive Economic Zone and the information presented in this article may aid in identifying areas where historic shipwrecks may lie. Maps and documents found during this study helped piece together the evolution of our understanding of the Gulf of Mexico surface circulation and how this knowledge influenced sailing during colonial times.  相似文献   
77.
This work analyses the main Spanish legislative and urban planning instruments, highlighting some of the most important structural problems of the current Spanish urban realities. The survey on legislation runs from the first Land Use Act of 1956 to the decentralization of the administration and the culmination of the transfer processes to the respective Spanish regions. Later, we study the complete well-structured hierarchy of urban planning instruments in use at present. Finally, we analyse how these and other factors have an influence on the capacity to control housing prices and on a lack of sustainability characterized by the excessive urbanizing use of the land.  相似文献   
78.
The paper deals with dendrochronological and radiocarbon dating of subfossil trunks found in the basin of the Morava River. The research into subfossil trunks had been conducted in the Czech Republic in the past but the research stopped in 2001. 160 records of measurements of subfossil, predominantly oak trunk samples, are preserved from that time. Three years ago the research was reopened and again the most trunks were found in the basin of the Morava River. 92 samples of oak trunks and 7 samples of other tree species (poplar, elm, maple, beech) were taken from selected sites. The samples were processed in compliance with the standard dendrochronological methodology. To date the samples, Czech, Austrian, Polish and German standard chronologies were used. In cases when the dendrochronological dating was unsuccessful, the samples were sent for radiocarbon dating. In total, 35 samples were dated, mainly by the radiocarbon method. Subfossil trunks from gravel pit Tovačov were dated and classified into 4 different periods, the oldest being from 2780–2190 BC. In Osek nad Bečvou, the samples were taken from two sites. Whereas from the 4 trunks taken in the river channel each was from a different period, the trunks from the gravel pit come from 981–1015 AD. The trunks found in the Morava River basin near Strážnice were dated to the 10th–15th century. In the future, we expect to extend the amount of the acquired samples with the aim to create a link to the existing standard chronology or to create a long floating average treering curve.  相似文献   
79.
Determination of the source of Spondylus objects is essential for the interpretation of Late Neolithic exchange systems and the social role of shell ornaments. We performed stable isotope analysis combined with cathodoluminescence microscopy study on ornaments (beads, bracelets) made of Spondylus shells excavated at the Aszód-Papi földek archaeological site in Hungary, to define their origin. For comparison Spondylus finds from Neolithic sites of Greece, modern Spondylus shells from the Aegean and the Adriatic, as well as fossil Spondylus and Ostrea shells from the Carpathian Basin were also examined. Oxygen isotope composition of Spondylus finds from Aszód ranges between ?1.9 and 2.1‰ and overlaps with the oxygen isotope range of shell objects from other Neolithic sites. Modern Spondylus shells from the Aegean and the Adriatic show overlapping δ18O values with one another and with the Neolithic objects; while recent shells of the Black Sea clearly are separate isotopically from the Mediterranean ones and most of archaeological artefacts. Spondylus shells from the Aszód site have Mediterranean origin; their source can be the Aegean or the Adriatic. Based on a former strontium isotope study the use of fossil Spondylus shells is excluded as raw material used for ornaments, however, in recent years the use of fossil shells was reintroduced. The shell ornaments from Aszód-Papi földek and the fossil oyster shells collected from the Carpathian Basin exhibit some overlapping oxygen isotope values; however, cathodoluminescence microscopy indicates that the Spondylus objects retained their original aragonite material. Diagenetic calcite, which occurs typically in the fossil shells, was not detected in the ornaments suggesting that the studied objects were made of recent shells. Calcitic parts observed in some Spondylus objects are not related to fossilisation.  相似文献   
80.
This paper continues the characterization of the lead isotopic fingerprint of ancient copper mines in the north‐west of Spain. In this work, the lead isotopic compositions found in copper ores from the La Profunda mine are presented. Azurites and malachites sampled from this deposit were subjected to lead isotope analysis by multicollector ICP–MS. The results showed a clear radiogenic lead signature compatible with the presence of uranium‐rich minerals (such as zeunerite) in the same mining complex. Moreover, a rare copper artefact, found in the galleries of the mine during its modern exploitation, was also analysed and showed that local mineral was used for its manufacturing.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号