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   22520篇
  免费   1962篇
  国内免费   1391篇
  25873篇
  2024年   58篇
  2023年   406篇
  2022年   346篇
  2021年   402篇
  2020年   866篇
  2019年   881篇
  2018年   839篇
  2017年   965篇
  2016年   907篇
  2015年   607篇
  2014年   831篇
  2013年   2535篇
  2012年   489篇
  2011年   669篇
  2010年   575篇
  2009年   833篇
  2008年   1052篇
  2007年   1111篇
  2006年   1056篇
  2005年   919篇
  2004年   789篇
  2003年   653篇
  2002年   580篇
  2001年   367篇
  2000年   327篇
  1999年   301篇
  1998年   239篇
  1997年   204篇
  1996年   159篇
  1995年   144篇
  1994年   134篇
  1993年   110篇
  1992年   91篇
  1991年   60篇
  1990年   60篇
  1989年   44篇
  1988年   52篇
  1985年   423篇
  1984年   476篇
  1983年   377篇
  1982年   470篇
  1981年   455篇
  1980年   459篇
  1979年   418篇
  1978年   486篇
  1977年   384篇
  1976年   381篇
  1975年   289篇
  1974年   285篇
  1973年   246篇
排序方式: 共有10000条查询结果,搜索用时 6 毫秒
231.
To examine to what degree argumentation skills are mastered by pupils who attend the vocational, general and academic streams in Dutch secondary education various subtests were constructed. The theoretical study of argumentation as exposed by Van Eemeren and Grootendorst was the basis for this test construction. In this article tests for the identification of singular, multiple and subordinate argumentation are described. Also an account is given of a pretest of these three subtests.  相似文献   
232.
The degree of structural and functional specialization that differentiates between upper and lower limb use in humans is quite unparalleled among primates. It is argued that less neural resources are devoted to leg and foot control than to arm and hand control, and that this aspect of lower limb innervation, together with the uniquely restricted use of the lower limb, renders lower limb function more sensitive to general neural insult. In addition, the status of leg and foot control differs from that of arm and hand control both early in life and during the later years of decline.  相似文献   
233.
The issues involved in decision making about the aggressiveness of future medical care for older persons are explored. They are related to population trends, the heterogeneity of older persons and a variety of factors involved in individual preferences. Case studies are presented to illustrate these points, as well as a review of pertinent literature. The argument is offered that, considering these many factors, a system of flexible, individualized care by informed patient preference, is more rational than the rationing of technological services by age.  相似文献   
234.
This paper examines the ethical issues of conflict of interest raised by the burgeoning development of physician involvement in for-profit entrepreneurial activities outside their practice. After documenting the nature and extent of these activities, and their potential for conflicts of interest, the paper assesses the major arguments for and against physicians' referral of patients to facilities they own or in which they invest. The paper concludes that an outright ban on such activity seems ethically warranted.  相似文献   
235.
The paper is an attempt to review the basis for the claim that physicians have a professional obligation to treat AIDS patients. Considered are the historical record, two professional codes of ethics, and several recent articles. The paper concludes that the arguments considered, which attempt to support the claim that physicians have an obligation to treat, fail. It is suggested, rather, that common humanity, which physicians share with those who suffer from AIDS, ought to be the basis for engaging in the care of AIDS patients.  相似文献   
236.
Philip Hefzer 《Zygon》1993,28(1):77-101
Abstract. The paper consists of an argument that goes as follows. Symbols and their elaboration into myths constitute Homo sapiens 's most primitive reading of the world and the relation of humans to that world. They are, in other words, primordial units of cultural information, emerging very early in human history, representing a significant achievement in the evolution of human self-consciousness and reflection. The classic myths of Fall and Original Sin, as well as the doctrines to which they gave rise, are further interpretations of this primordial information. The doctrinal traditions of the first four centuries of Christianity are surveyed. Three sets of data as interpreted by the biological sciences are offered as resources for understanding the biogenetic grounds of the experience that the symbols, myths, and doctrines of Fall and Original Sin seek to interpret. The conclusions to be drawn are that (1) the symbolic material is indeed commensurate with the scientific understandings, and (2) the scientific interpretations deepen our understanding of the symbols, while (3) the conversation between the symbols and the science once again raises certain perennial questions about human existence.  相似文献   
237.
238.
239.
240.
驾驶员心理品质检测中的杆型人形图法   总被引:1,自引:0,他引:1  
在汽车驾驶员心理品质检测研究中,我们根据数学中的多变量图分析方法,并汲取简笔画的优点,用19个人形图变量代表检测所得的17种心理品质数据,来具体、形象地再现每个驾驶员心理品质变量的整体关系。这对于检测结果的分类或进行系统化分析具有重要的实用意义。  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