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   1589篇
  免费   8篇
  1597篇
  2025年   1篇
  2024年   5篇
  2023年   2篇
  2022年   3篇
  2021年   5篇
  2020年   12篇
  2019年   3篇
  2018年   279篇
  2017年   208篇
  2016年   239篇
  2015年   13篇
  2014年   10篇
  2013年   21篇
  2012年   37篇
  2011年   176篇
  2010年   194篇
  2009年   65篇
  2008年   93篇
  2007年   90篇
  2006年   35篇
  2005年   44篇
  2004年   15篇
  2003年   10篇
  2002年   11篇
  2001年   15篇
  2000年   3篇
  1999年   5篇
  1998年   1篇
  1997年   1篇
  1976年   1篇
排序方式: 共有1597条查询结果,搜索用时 0 毫秒
981.
982.
983.
Humans use animals as a means of creating and manipulating relationships with other human beings. This process occurs both through the use of animals for food or raw materials and through the use of animals as literary and artistic symbols. Cervus elaphus is Irelands only indigenous deer species. It is also unique in being the only native Irish, wild animal to appear frequently in medieval texts, iconography, and archaeological deposits. This paper brings together diversesources of information to illuminate how early medieval monasteries used reddeer to establish an identity for themselves and to conceptualize socioeconomic relationships with others.  相似文献   
984.
藉1931年至1933年《光华日报》及《槟城新报》的报道,讨论了粤籍人士谢湘任中华民国驻槟榔屿领事期内,在履行保护和管理华侨、组织劝导华侨捐款救灾、促进商务交流提倡国货、发展海外华文教育及履行国府任务等职责中的表现,探讨了其上任一年半被免职的原因及该事件所折射出的槟城华人社会的种种侧面。从槟城华文报纸对谢湘免职的不同立场,可以看出这是一个有争议的历史问题,谢湘之被免职不仅与其任内的表现有关,还与槟城华侨社会不同方言群间的复杂权力关系有关,在深层次上凸显了福建方言群与广东方言群在主导当时槟城华人社会中的重要作用。被免职的谢湘极有可能是槟城华人社会帮权争斗下的一个牺牲品。  相似文献   
985.
在明清人相关的文集、书画集和诗词选集中,有些词作尚未进入整理者的视野。今特辑词作17首、补词人4位,以减少明词整理的遗珠之憾。  相似文献   
986.
    
This paper focuses on the study of simulations for spatially variable seismic underground motions in U-shaped canyons. First, a canyon ground cross-coherence function based on commonly used coherence function models of flat terrain, is deduced and presented. To further obtain the underground cross-coherence function, a mathematical expression, including its specific deduction process for describing the relationship between coherence functions of multi-support ground and underground motions, is also given in detail and adopted. Then, the key factors (i.e. canyon underground power spectrum density and canyon underground coherence function) for simulating the spatially variable seismic underground motions are obtained by a two-step transferring method from flat-ground to underground soil. Furthermore, a program is coded for generating the spatially variable seismic underground motions. The effectiveness of the generated seismic motions is further verified. Finally, two numerical examples are taken to validate the proposed simulation approach, illustrating the specific characteristics of canyon coherence function. The analysis results show the apparent differences of the simulated seismic motions using the canyon coherence function from those using conventional coherence function models of flat terrain. The proposed approach provides some insights for anti-earthquake analysis of soil-structure interaction or underground structures in canyon topography.  相似文献   
987.
    
The Ji'erzankale Necropolis (吉尔赞喀勒墓地) is located on the Pamir Plateau in the Xinjiang Uyghur Autonomous Region of China. Composed of numerous stone circle graves and directly radiocarbon dated to the Iron Age (ca. 2400–2600 years cal BP), this site is unique in that numerous lines of archaeological evidence suggest that those interred here were followers of the Zoroastrian religion. Here, we present carbon (δ13C) and nitrogen (δ15N) stable isotope ratio measurements of seeds (Nitraria pamirica, n = 7), animals (n = 14), and humans (n = 24) to reconstruct ancient diet and lifeways at the Ji'erzankale Necropolis. The results of the N. pamirica reflect the natural C3 vegetation and arid environment of this region. The δ13C (mean ± SD = –18.6 ± 0.8‰) and δ15N (mean ± SD = +8.1 ± 1.6‰) results of the animals (13 sheep and 1 hare) display a mostly C3 terrestrial diet with variable levels of protein consumption. Adult humans (n = 19) have δ13C (mean ± SD = –17.9 ± 0.2‰) and δ15N (mean ± SD = +13.1 ± 0.3‰) results that tightly cluster above the sheep by approximately +5‰. This is evidence that the diet of this population was relatively homogenous and mainly based on sheep and/or their secondary products and did not have a large input of C4 crops such as foxtail (Setaria italica) or common millet (Panicum miliaceum).  相似文献   
988.
    
Instead of the conventional approach to sectioning tooth dentine horizontally for isotope analysis, a new serial sampling strategy has been developed recently. This new method considers the developmental direction of growth lines in dentine when samples are sectioned. It can therefore provide more precise and detailed information about an individual's dietary history, including breastfeeding/weaning patterns, infant feeding experiences, and dietary shifts throughout the early life of an individual. In order to enhance our understanding of human groups in ancient Sichuan, it is practical and necessary to apply this new technique to archaeological samples from this region. In this study, carbon and nitrogen isotope compositions of bone and serial dentinal collagen from two Yingpanshan human individuals (M32 and M40) were analysed and compared, in order to reveal the dietary history during their lifetime. Results indicate that their long‐term averaged diets after childhood consisted of both C3 and C4‐type foods, predominantly the former. The contribution of animal protein to the childhood diet of individual M40, between the ages of 3.0 and 7.5, was similar to his long‐term averaged diet after childhood. He had also consumed more millets during the childhood. By comparison, individual M32 consumed more animal protein and likely also more C3‐type foods between the ages of 4.5 and 13.5 than after childhood. Little variations in δ15N dentinal collagen of each individual suggest that the relative consumption of animal to plant foods in their respective diets was more or less consistent in their childhood. However, the larger variations in the δ13C values of dentine samples show that the proportion of C3 and C4‐plant foods in their respective diets varied at different phases in their childhood. The variations are probably related to environmental factors and/or human behaviour. The dietary history and weaning practices revealed by using this technique also indicate that the two individuals might have been non‐locals or received some foods that originated from the outside.  相似文献   
989.
990.
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