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   11852篇
  免费   213篇
  国内免费   332篇
教育   7702篇
科学研究   2973篇
各国文化   105篇
体育   359篇
综合类   494篇
文化理论   37篇
信息传播   727篇
  2024年   3篇
  2023年   38篇
  2022年   99篇
  2021年   167篇
  2020年   213篇
  2019年   251篇
  2018年   251篇
  2017年   236篇
  2016年   204篇
  2015年   266篇
  2014年   673篇
  2013年   1171篇
  2012年   769篇
  2011年   864篇
  2010年   745篇
  2009年   775篇
  2008年   792篇
  2007年   772篇
  2006年   834篇
  2005年   740篇
  2004年   626篇
  2003年   557篇
  2002年   364篇
  2001年   307篇
  2000年   205篇
  1999年   82篇
  1998年   53篇
  1997年   61篇
  1996年   29篇
  1995年   24篇
  1994年   37篇
  1993年   24篇
  1992年   18篇
  1991年   16篇
  1990年   4篇
  1989年   22篇
  1988年   10篇
  1987年   8篇
  1986年   2篇
  1985年   20篇
  1984年   15篇
  1983年   6篇
  1982年   13篇
  1981年   9篇
  1980年   3篇
  1979年   6篇
  1978年   6篇
  1977年   4篇
  1976年   2篇
  1974年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
谈义乌市公示语的英译   总被引:1,自引:0,他引:1  
良好的国际化语言环境是国际化城市建设的保证。义鸟市公示语英译还存在着浮于表面的解读、选词欠地道、简单的字字对应、不规范的书写等不足。针对这些问题,建议采取建立行政管理机构、推行翻译人员持证上岗制度、加强公众舆论监督等具体措施。  相似文献   
62.
The prevalence of ischaemia-related symptoms is remarkably high among elite indoor volleyball players. Since the exposure to sport-specific demands may be higher in beach volleyball compared to indoor volleyball, the aim of this study was to assess the prevalence of ischaemia-related symptoms and associated risk factors among world-class beach volleyball players. Therefore, a questionnaire survey was performed among beach volleyball players active during the 2013 Grand Slam Beach Volleyball in the Netherlands. In total, 60 of the 128 beach volleyball players (47%) participated: 26 males and 34 females from 17 countries. The self-reported prevalence of cold or blue or pale digits in the dominant hand during or immediately after practice or competition was 38% (n = 23). Two risk factors were independently associated with symptoms of blue or pale digits: more than 14 years playing volleyball (odds ratio (OR) 4.42, 90% confidence interval (90% CI) 1.30–15.07) and sex (female) (OR 4.62, 90% CI 1.15–18.57). In conclusion, the prevalence of symptoms associated with digital ischaemia is high among international world-class beach volleyball players. Female sex and the length of the volleyball career were independently associated with an increased risk of ischaemia-related symptoms. The high prevalence of these seemingly innocuous symptoms and possible associated risk factors warrant regular monitoring since early detection can potentially prevent thromboembolic complications and irreversible tissue damage.  相似文献   
63.
The analysis of the joint kinematics during swimming plays a fundamental role both in sports conditioning and in clinical contexts. Contrary to the traditional video analysis, wearable inertial-magnetic measurements units (IMMUs) allow to analyse both the underwater and aerial phases of the swimming stroke over the whole length of the swimming pool. Furthermore, the rapid calibration and short data processing required by IMMUs provide coaches and athletes with an immediate feedback on swimming kinematics during training. This study aimed to develop a protocol to assess the three-dimensional kinematics of the upper limbs during swimming using IMMUs. Kinematics were evaluated during simulated dry-land swimming trials performed in the laboratory by eight swimmers. A stereo-photogrammetric system was used as the gold standard. The results showed high coefficient of multiple correlation (CMC) values, with median (first–third quartile) of 0.97 (0.93–0.95) and 0.99 (0.97–0.99) for simulated front-crawl and breaststroke, respectively. Furthermore, the joint angles were estimated with an accuracy increasing from distal to proximal joints, with wrist indices showing median CMC values always higher than 0.90. The present findings represent an important step towards the practical use of technology based on IMMUs for the kinematic analysis of swimming in applied contexts.  相似文献   
64.
1.Introduction The reproduction systems of 3D images without using eyeglasses and other special accessories has always attracted attention and aroused great interest of developers and consumers of such equipment because of totally accurate image and method of its presentation.Such systems can be used and are already partially used in advertising,television,different devices (i.e.smartphones,tablet computers),at the exhibitions,etc.,as well as in various technical applications,training systems,simulators,etc.  相似文献   
65.
本文分析了数据库系统的不安全因素.在简要介绍JAVA安全体系结构基础上结合JAAS来实现对用户身份的验证和授权以达到保护用户连接的目的、利用JSSE实现SSL隧道封装保护JDBC的传输,接着讨论了利用数据库管理系统提供的一些安全机制来加强数据库的安全.文章最后还提出了对高度机密的数据采用数据库加密的解决方案.  相似文献   
66.
INTRODUCTION Shield tunnel method has become the most pre- ferred method in city tunnel construction because of its excellent attributes: little effect on surrounding environment, fast and safe construction, outstanding performance in earthquake resistance, etc. (Zhang et al., 2004). In different shield tunnels, the arrangement and number of segments are different, but the whole assembling process is generally the same. The as- sembling process begins with A2P, then A1P, A3P, BP, CP, …  相似文献   
67.
在国内外的研究基础上,结合安徽特有的基本情况,建立了一套评价安徽省各市R&D投入产出综合水平指 标体系,运用主成分分析和聚类分析,客观的评价了安徽省各地市R&D投入产出水平。评价结果表明,“合芜蚌”试验 区引领带动着全省R&D投入产出水平,“皖江带”城市R&D投入产出水平两极分化严重,而“皖北”地区则有崛起的势 头,从而为各市提升R&D投入产出水平提供参考依据。  相似文献   
68.
食用茉莉花香味成分的GC/MS分析   总被引:6,自引:0,他引:6  
采用水蒸气蒸馏-乙醚萃取法对云南引种食用茉莉花中芳香性成分进行了提取,并用气相色谱-质谱联机技术对其中化学成分进行分析鉴定.共鉴定出46种芳香性有机成分,占茉莉花挥发油提取物总含量的99.9005%.通过对食用茉莉花芳香性成分的分析,为茉莉花香精香料的开发提供了依据.  相似文献   
69.
从研究“A,但B”为代表的转折句的类别及构成方法入手,为对转折句进行语义分析提供方法和途经.根据A、B所表达的概念之间是否具有属种关系,将“A,但B”分为属种关系转折句和非属种关系转折句;根据A、B所断定的两种事物情况是否在同一个语义层面上,将“A,但B”类转折句分为相同语义层面上的相反相对和不同语义层面上的相反相对;根据A、B之间的逻辑联系来分类,将“A,但B”分为并列式、连贯式、递进式、选择式、因果式等转折句。“A,但B”类转折句构成的逻辑方法主要有求同法、求异法、限制法,概括法、排除法、对照法等.  相似文献   
70.
《红楼梦》作者通过对贾宝玉独特心理成长过程的描写 ,揭示了贾宝玉的性格是其独特生理、心理成长的结果 ,又是一种社会影响的结果 ,还是一种传统历史文化的载体 ;正是有了这一女性化心理细致深入的描写才使贾宝玉这一形象更加有血有肉 ,而成为不朽的典型  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