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   492篇
  免费   20篇
  2024年   3篇
  2023年   11篇
  2022年   9篇
  2021年   10篇
  2020年   20篇
  2019年   19篇
  2018年   26篇
  2017年   12篇
  2016年   16篇
  2015年   12篇
  2014年   14篇
  2013年   92篇
  2012年   33篇
  2011年   35篇
  2010年   26篇
  2009年   24篇
  2008年   26篇
  2007年   17篇
  2006年   17篇
  2005年   14篇
  2004年   10篇
  2003年   10篇
  2002年   15篇
  2001年   7篇
  2000年   11篇
  1999年   6篇
  1998年   2篇
  1996年   2篇
  1994年   3篇
  1993年   2篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1985年   1篇
  1984年   1篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
排序方式: 共有512条查询结果,搜索用时 15 毫秒
31.
毛泽东与中国科学技术的自主研发   总被引:2,自引:0,他引:2  
毛泽东将科学技术视为革命者完成自身历史使命的重要工具,他洞见先进技术在后发国家追赶发达国家中的作用,将大力发展科学技术视为国家的重要职能,在西方国家封锁禁运、苏联毁约的困境下,千方百计引进先进科技并努力促进自主研发,果断地发展高科技产业,提高中华民族的国际地位,为中国进一步发展打下了基础。回顾毛泽东与中国科学技术自主研发的历程,有助于我们深刻认识和实践新形势下中共中央、国务院做出的建设创新型国家的重大战略决策。  相似文献   
32.
This paper explores the materiality of social power relationally through study of social interactions with artifacts. Specifically, it is argued that acquisition of an artifact instantiates social power by imposing interactions on groups taking part in that artifact's life-history activities. We introduce the “performance-preference matrix,” an analytic tool for systematically studying the effects of such acquisition events on activity groups. The use of the performance-preference matrix is illustrated through an example: the acquisition of electric-arc lights for lighthouses in the 19th century. Suggestions are offered for analyzing culture-contact situations and for handling singularized artifacts such as heirlooms and monuments.
William H. WalkerEmail:
  相似文献   
33.
Two Taiwan-based economists estimate the technology content of exports by the machinebuilding industry of the East Asia region during 2004-2008, using comparative analysis to clarify changes in the relative competitiveness of four East Asian nations (China, Japan, South Korea, and Taiwan) accompanying the formation of a regional trading bloc and production networks. In particular, they examine the technology content of these countries' machinebuilding sub-industries' exports within the Southeast Asian market (documenting the rise of the machinebuilding industry in China) as well as the penetration of Japanese, South Korean, and Taiwanese sub-industries into China's market. The results point to areas of emerging competition among China, South Korea, Japan, and Taiwan for East Asian markets, which can only be expected to intensify in the future. Journal of Economic Literature, Classification Numbers: F14, F15, F36, O14, P23. 7 tables, 36 references.  相似文献   
34.
我国考古和文物保护工作中物探技术的应用   总被引:7,自引:0,他引:7  
20世纪80年代以来,物探技术在考古和物保护方面应用越来越多,在古墓探查、大型古建筑地下遗存现状探查、重要古建基础状况探查、古遗迹断代等方面,地球物理技术都找到了发挥作用的机会。本通过地球物理技术在云冈石窟、龙门石窟、克孜尔石窟、北京故宫紫禁城、嵩岳寺塔、古泗州城遗址、风阳明中都等的物理探查实例,以及查找古墓、古遗迹断代等方面的工作,介绍了我国在考古和物保护领域应用地球物理技术的进展,并指出了物探在用于考古和保时的特点和展望。  相似文献   
35.
运用科学技术方法对清代珐琅的研究   总被引:4,自引:0,他引:4  
作者运用原子发射光谱、扫描电子显微镜、偏光显微镜和金相显微镜,对故宫博物院藏清代珐琅残片进行了实验分析。研究中.对构成珐琅的硅酸盐材料、铜材料、焊接材料以及镀金层的元素组成进行了测试;对珐琅残片断面的焊接层和镀金层的微观形貌、焊接层的金相组织进行了观察和鉴别。在此基础上,运用结晶学、矿物学、金属学和金相学的基础理论对珐琅原料种类、各种原料的作用、珐琅料的熔制与烧蓝、铜材料与焊接材料的合金属性、焊层的金相组织、掐丝珐琅的烧制工艺等问题加以探讨,试图藉现代科技手段揭示清代珐琅所包含的科学技术内涵。  相似文献   
36.
安图沙金沟旧石器遗址发现的石器研究   总被引:3,自引:0,他引:3  
安图县沙金沟遗址于2006年发现,遗址位于沙金河右岸第Ⅲ级阶地上,在地表和含角砾的黄色亚黏土层中共发现石器82件,原料以黑曜岩为主,包括石核、石片、石叶、细石叶、二类和三类工具(刮削器、雕刻器、尖状器和砍砸器等)。遗址的地质年代推测为晚更新世的晚期,即旧石器时代晚期。  相似文献   
37.
Modern technology lends itself to holistic exploration and widely accessible outreach. New technology allows scientists studying our planet either from space or deep under the seas, to explore and reveal both natural and cultural resources that have previously escaped our scrutiny. However, the use of these new technologies is expensive and often the exclusive tool of industrial research. Yet, these new technologies can lead the way to greater collaboration, better science and more public access. In 2003 and 2004, a landmark project, combining government agencies, industrial technology and outreach set new standards in collaborative scientific exploration. The project focused on six shipwrecks at depth in the Gulf of Mexico. The questions posed by the project illuminate how science and industry can collaborate to produce remarkable results. The papers presented in this issue form a model for deepwater exploration.  相似文献   
38.
Skill is central to the identification of the individual within lithic analysis. Modern replication tends to focus on the proficient flintknapper, and emphasises complex, technically demanding implements and high quality raw materials. Yet, acquiring lithic skill is a universal process that manifests itself in various ways depending on technological strategy and raw material. This paper presents the results of a programme of experimental replication that explores notions of consistency and identity. Based on Mesolithic blade technology, using direct percussion reduction and variable pebble resources, it compares knappers with different experience and identifies some salient parameters of individual performance.  相似文献   
39.
再读跨湖桥     
在《跨湖桥》考古报告的基础上,本文运用浮选、孢粉和非孢粉微化石、PIXE技术和拉曼光谱等多种分析手段,对跨湖桥遗址的人工制品和生态物进行了分析,复原了当时人类的居住环境及变迁、古食谱和制陶技术,从文化生态的角度探讨了先民的生存方式。文章认为,8000年前跨湖桥的富裕环境很可能促使复杂采集狩猎经济的发展,并出现比较复杂的社会结构,而水稻栽培和猪的驯养很可能与这类社会常见的仪式和宴享活动有关。  相似文献   
40.
The archaeological record of Oldowan hominins represents a diverse behavioral system. It has been suggested that exploitation of lithic resources by Oldowan hominins was simplistic and represented mostly use of local sources of stone. Here we investigate the raw material selection and transport behaviors of Oldowan hominins reflected in the stone artifact assemblages from the Kanjera South Formation, South Rachuonyo District, Kenya. Using geochemical methods (ED-XRF) artifacts are linked to primary and secondary source outcrops throughout southwestern Kenya. These data show that hominins selected raw materials for transport at frequencies that are significantly different from their availability on ancient landscapes. Furthermore, a substantial proportion of the assemblage represents transport over relatively long distances (>10 km). Our study further suggests that in the early stages of stone tool use hominins used a wide variety of raw materials and selected these materials at some distance from their eventual discard locations. Early hominin behavior may have incorporated an understanding of raw material source distributions across a more extensive landscape than has been previously documented. This supports the growing perspective that Oldowan technology represents a more complex behavioral pattern than is usually associated with the beginnings of hominin tool use.  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