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   11035篇
  免费   332篇
  国内免费   2篇
  2020年   108篇
  2019年   137篇
  2018年   164篇
  2017年   184篇
  2016年   230篇
  2015年   171篇
  2014年   206篇
  2013年   1153篇
  2012年   358篇
  2011年   405篇
  2010年   284篇
  2009年   270篇
  2008年   370篇
  2007年   417篇
  2006年   407篇
  2005年   356篇
  2004年   327篇
  2003年   351篇
  2002年   348篇
  2001年   158篇
  2000年   177篇
  1999年   160篇
  1998年   177篇
  1997年   158篇
  1996年   166篇
  1995年   156篇
  1994年   157篇
  1993年   130篇
  1992年   142篇
  1991年   134篇
  1990年   117篇
  1989年   119篇
  1988年   117篇
  1987年   125篇
  1986年   129篇
  1985年   142篇
  1984年   145篇
  1983年   155篇
  1982年   173篇
  1981年   161篇
  1980年   150篇
  1979年   125篇
  1978年   165篇
  1977年   154篇
  1976年   144篇
  1975年   142篇
  1974年   145篇
  1973年   136篇
  1972年   107篇
  1968年   72篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
231.
232.
233.
In this commentary on a study by H. Steven Moffic, et al., of the current status of the Hippocratic Oath in medical education, Veatch discusses the relation of the oath to ethical conduct, the meaning of primum non nocere ("do no harm"), and the limitations of practicing Hippocratic ethics.  相似文献   
234.
This investigation focused on the interrelationships among students' study activities, students' self-concept of academic ability ratings, students' academic achievement, and instructional practices in 12 high school biology courses. Using a framework derived from a previous investigation, course features were classified into those that appear to (a) place demands on, (b) support, or (c) compensate for student engagement in particular study activities. Students' study activities, self-concept of academic ability ratings, and achievement were measured with experimenter-developed instruments. Results are reported for (a) characteristics of instruments and course features, (b) relationships between central factors of the investigation, and (c) multi-level relationships between course features and student variables. Results at the student level indicated that self-concept of academic ability and, to a lesser extent, students' study activities were positively associated with student achievement. Students' self-concept of academic ability ratings were also linked to students' engagement in generative, proactive study activities. At the course level the supportive practices of providing challenging homework assignments and extensive feedback on student coursework were associated with student engagement in effortful, generative, proactive study activities. The provision of extensive feedback was also associated with high student achievement. Multi-level relationships were analysed using hierarchical linear modelling (HLM) analyses. These analyses revealed, for example, that in courses in which little or no feedback is given on homework assignments, the relationship between achievement and student engagement in diligent effort management activities was enhanced. Other HLM analyses were conducted to examine the mediating role of course features on the relationship between students' self-concept of academic ability and their study activities and achievement. For example, the presence of challenging course demands was associated with an enhancement of the relationship between self-concept of academic ability and achievement whereas the presence of instructor provisions (supports and compensations) designed to reduce course demands was associated with a reduction in this relationship.  相似文献   
235.
236.
237.
238.
239.
240.
The crane's foot: The rise of the pedigree in human genetics   总被引:1,自引:1,他引:0  
The standard pedigree used by geneticists is intimately connected to the history of genetics. Pedigrees drawn today are based on standards established in the early decades of the twentieth century. Those standards were established by geneticists who pursued an active interest in eugenics. The slightly different standards followed in America vs. England to some extent followed the stronger support of Mendelism by the Americans, as well as the individual preferences of the leading human geneticists in those countries.  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