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   597篇
  免费   20篇
  2023年   3篇
  2022年   6篇
  2021年   2篇
  2020年   20篇
  2019年   23篇
  2018年   25篇
  2017年   22篇
  2016年   21篇
  2015年   11篇
  2014年   22篇
  2013年   136篇
  2012年   38篇
  2011年   40篇
  2010年   32篇
  2009年   38篇
  2008年   37篇
  2007年   21篇
  2006年   18篇
  2005年   18篇
  2004年   13篇
  2003年   8篇
  2002年   7篇
  2001年   7篇
  2000年   12篇
  1999年   6篇
  1998年   3篇
  1997年   4篇
  1996年   2篇
  1995年   2篇
  1994年   4篇
  1993年   1篇
  1992年   1篇
  1991年   2篇
  1990年   1篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1985年   1篇
  1984年   2篇
  1981年   1篇
  1980年   1篇
  1978年   1篇
排序方式: 共有617条查询结果,搜索用时 15 毫秒
21.
We present the palaeopathological analysis of a right fourth metatarsal (ATD6‐124) recovered from the Atapuerca–Gran Dolina site (Spain). This fossil, ca. 1 Ma, belongs to Homo antecessor, the earliest known European hominin species. The metatarsal exhibits a proliferative lesion on its medial periosteal surface. Periosteal reaction can be the bone response to a wide number of injurious processes. We describe a lesion on the basis of macroscopic and microscopic analyses, including microtomography and scanning electron microscopy. Externally, the osteoblastic lesion presents a highly porotic and disorganised morphology. Internally, we observe a series of micro‐fractures on the compact bone that do not affect the medullary canal. We provide a differential diagnosis and suggest that the ATD6‐124 lesion could correspond to a pedal stress fracture, also known as fatigue or march fracture. Stress fractures have been related to a load increase and muscular fatigue. This type of fracture has been widely reported in the foot of soldiers and athletes, which are usually engaged in strenuous, excessive or prolonged locomotive activities. Despite its high frequency in these groups, stress fractures have not been reported as such in fossil collections, with the exception of a metatarsal belonging to the Sima de los Huesos site (Atapuerca). Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
22.
In 1957, a new discovery inside Temple XVIII‐A was made in Palenque, the Mayan archaeological site in Chiapas Mexico, a royal tomb of an original design which proved to be the oldest at the site. Two skeletons were found, the principal (PAL‐44) was at the centre showing red pigmentation on the surface of some bones, personal adornments and offerings, which indicate that he was an early ruler of Palenque. The second (PAL‐45), deposited at the entrance, not in a special mortuary position, without offerings, suggests it was of a lower social status. This research presents a new bioarchaeological analysis with the following results: (i) The result of a direct radiocarbon dating of PAL‐44 by accelerator mass spectrometry is 250–420 cal AD (LTL12759A:1696 ± 30 BP). This means that the personage was buried long before the first designated ruler of Palenque, who, according to the epigraphic record was enthroned in ad 431. (ii) With X‐Ray Fluorescence, the red pigment was identified as cinnabar (HgS). (iii) PAL‐44 is a young adult male with a severe idiopathic scoliosis with a double curvature that affected the ribcage and lower limbs. Such a three‐dimensional deformity resulted in changes to his body mechanics and induced motion asymmetry. Consequently, his health and mobility must have been significantly affected by such a severe condition. (iv) PAL‐45 is an adult female with signs of nutritional problems in childhood and entheseal changes probably related to her activity. Three ante‐mortem traumas are registered: rib fracture, frontal depressed circular fracture and a nasal septal deviation. This traumatic event took place two weeks, approximately, prior to PAL‐45's death. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
23.
程亦胜 《东南文化》2006,(1):31-39,i0002
越国建都会稽之前的早期越国都邑在何地有说在诸暨,也有说在萧山。根据太湖南岸,尤其是安吉古城遗址及其周围的古墓群等考古调查资料,结合史书关于吴越两国疆界及吴越罸李、夫椒两次战争等相关史料研究分析,早期越国都邑应该在古钱塘江以北的太湖南岸,秦汉时期的鄣郡郡治所在地,今安吉古城。  相似文献   
24.
中国"三农"问题的由来和发展   总被引:16,自引:1,他引:15  
中国在改革开放过程中出现的特有的城乡关系和特有的城乡发展路径,产生了中国特有的"三农"问题的理论.这个理论的形成和运用,对于深入认识我国的基本国情、用以指导社会主义现代化建设的实践和对其他国家的问题进行研究,都是很有意义的.我国"三农"问题总的情况是农业问题已经基本上得到了解决,但农民问题和农村问题还很严重,主要根源还在于计划经济体制下所形成的一套农村、农业政策还没有得到根本转变.解决农民问题和农村问题,要继续深化农村体制改革,下决心改革户籍制度,改革现有的土地承包制度,改革现有的国民收入分配格局和乡镇现有的政权体制包括财政体制.  相似文献   
25.
新中国诞生后,百废待兴。冀朝鼎在帝国主义实施禁运和经济封锁的困难面前,积极探索中国外经贸的新体制,加强外汇管理,以灵活的外交,与11个国家签定了外贸协定,还成功地与日本、英国等未建交国家进行“民间贸易”.打破西方列强的孤立政策.开创了中国对外交往与贸易的新局面。  相似文献   
26.
Kristin Reynolds 《对极》2015,47(1):240-259
Many studies have documented the benefits of urban agriculture, including increased food access, job creation, educational opportunities, and green space. A focus on its social benefits has fed an association of urban agriculture with social justice, yet there is a distinction between alleviating symptoms of injustice (such as disparate access to food or environmental amenities) and disrupting structures that underlie them. Despite its positive impacts, urban agriculture systems may reinforce inequities that practitioners and supporters aim to address. This paper reports findings from a 2‐year study of urban agriculture in New York City, which found race‐ and class‐based disparities among practitioners citywide. Using the lens of critical race theory, it argues that a failure to examine urban agriculture's role in either supporting or dismantling unjust structures may perpetuate an inequitable system. The paper concludes with recommendations for urban agriculture supporters and scholars to help advance social justice at structural levels.  相似文献   
27.
Within Iran, there is little archaeological evidence for relationships between newly arrived Early Trans-Caucasian (ETC) or Kura-Araxes settlers and earlier inhabitants and contact with neighbouring cultures, or for their apparently abrupt end. Based on the evidence, the Iranian Kura-Araxes was not a simple ‘copy' of the Caucasian Kura-Araxes package. Ceramic traditions show local peculiarities, and all are elements suggesting that the Kura-Araxes traditions went through processes of adaptation, change and re-elaboration according to local tastes and technologies. In this study, an archaeometric approach to ceramics in the Kolyaei Plain of central Zagros contributes to the discussion of contact and exchange between indigenous communities and several cultural spheres of influence on the Early Bronze Age (beginning in the fourth millennium bce ). Morphological data, as well as the mineralogical and chemical composition of ceramics, were applied to determine the major and trace elements of the pottery shards. Based on the trace element profiles, it can be suggested that all the pottery shards are in the same group and they strongly are local products. The ceramic provenance indicates the same patterns of material interactions during the ETC or Kura-Araxes in all the sites within the Kolyaei Plain.  相似文献   
28.
Incentive programs to encourage landowners to protect habitat should be carefully designed to avoid motivation crowding: basically, replacing intrinsic reasons such as a land ethic with extrinsic ones like payments. Little research on motivation crowding tests real programs, and no such work has been done in Canada. We surveyed farmers in Nova Scotia in 2017 to explore whether participation in a new incentive program called Wood Turtle Strides, or knowledge about a similar incentive program potentially available in the future, would alter reported motivations to use riparian setbacks and buffers. Motivations to use setbacks or buffers were heavily intrinsic across all four survey cohorts: wildlife stewardship and sacrifice motivated actions more than social pressures. We were not able to statistically test for motivational crowding due to low program uptake and thus post-program survey responses, but there was no evidence of second-hand crowding: farmers being motivated by hearing about a program in an adjacent jurisdiction. Findings point to the significance of wildlife stewardship for many farmers, and persistent resistance to conservation among others, as well as a risk of low additionality. More post-program research is necessary to fully understand the program's net impact on motivations and conservation.  相似文献   
29.
The study analyses the chemical composition of 57 glass samples from 40 beads discovered at 20 archaeological sites in Poland. The beads are dated to Hallstatt C–Early La Tène periods (c.800/750–260/250 bce ). Analyses were carried out using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Two groups were distinguished among the glasses based on the MgO/K2O ratio: high-magnesium glass (HMG), five samples; and low-magnesium glass (LMG), 52 samples. The former were melted with halophyte plant ash, the second with mineral soda. These glasses were produced in the Eastern Mediterranean (more likely in Mesopotamia or Syro-Palestine than in Egypt) and transported in the form of semi-products to secondary glass workshops in Europe. Some of the white opaque glass was coloured and opacified in Europe.  相似文献   
30.
European and indigenous artifacts from a grave near a mound on Pine Island in the Tennessee River near Guntersville, Alabama, donated to the Yale Peabody Museum of Natural History in 1915, included a group of fabric fragments. The fragments, which incorporate interlaced bison-hair yarns, most likely represent portions of a sash, an accessory with a long history in Mississippian iconography but with few extant archaeological examples. This paper addresses fabric attributes, comparable archaeological and historical fabrics, and the social significance of this costume item.  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