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   38806篇
  免费   805篇
  国内免费   7篇
  2020年   205篇
  2019年   231篇
  2018年   3758篇
  2017年   3075篇
  2016年   2556篇
  2015年   466篇
  2014年   407篇
  2013年   1497篇
  2012年   1171篇
  2011年   2941篇
  2010年   2878篇
  2009年   1831篇
  2008年   2234篇
  2007年   2735篇
  2006年   524篇
  2005年   686篇
  2004年   586篇
  2003年   504篇
  2002年   494篇
  2001年   766篇
  2000年   765篇
  1999年   531篇
  1998年   250篇
  1997年   232篇
  1996年   230篇
  1995年   174篇
  1994年   173篇
  1992年   413篇
  1991年   380篇
  1990年   409篇
  1989年   335篇
  1988年   314篇
  1987年   313篇
  1986年   292篇
  1985年   295篇
  1984年   284篇
  1983年   238篇
  1982年   202篇
  1981年   169篇
  1979年   248篇
  1978年   191篇
  1977年   175篇
  1975年   204篇
  1974年   246篇
  1973年   243篇
  1972年   189篇
  1971年   181篇
  1969年   182篇
  1968年   213篇
  1967年   194篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Sprague-Dawley rats drank sweetened (3% dextrose + 0.144% saccharin, w/v) or unflavored water for 18 days and subsequent pain reactivity was assessed using a hot plate. Compared to the rats that consumed unflavored water, the rats that consumed sweet water responded more quickly on the hot plate indicating that their threshold for pain was lowered. Another group of rats given identical exposure to the fluids had their brains prepared for measuring opiate receptor binding using the delta-receptor ligand [3H]D-Ala-D-Leu-enkephalin ([3H]DADLE) and the mu-receptor selective ligand [3H]Tyr-D-Ala-Gly-MePhe-Gly-ol ([ 3H]DAGO). Binding of these opiates to mu- and delta-receptors in the cerebral cortex, striatum, hippocampus, hypothalamus, brain stem, and remaining brain regions was the same for the rats that drank sweet fluids and those that drank unflavored water. These findings suggest that drinking sweet fluids lowers pain thresholds but does not alter mu- and delta-receptors.  相似文献   
102.
Attribution questionnaires were completed by 137 students in an introductory economics course immediately preceding the first exam in their class and immediately after their exams were returned. Results indicate that males and females used attributions differently, although not as a function of perceived outcome. In contrast, sex-typing groups varied their attribution as a function of perceived outcome. Self-esteem is proposed as a possible mediating variable. It was concluded that sex typing in relation to perceived successful and unsuccessful performance is an important variable in attributional research.  相似文献   
103.
104.
105.
Attitudes toward older and younger adults: a meta-analysis   总被引:3,自引:0,他引:3  
Attitudes toward the elderly have been examined in a number of empirical studies, yet the question of whether the elderly are viewed more negatively than younger persons has not been resolved. A meta-analysis of the literature was conducted to examine this question; results demonstrated that attitudes toward the elderly are more negative than attitudes toward younger people. However, smaller differences between the evaluations of elderly and younger targets were found when (a) the study used measures of personality traits (compared with measures of competence), (b) there were a larger number of dependent measures included in the effect size, (c) specific information was provided about the target person (compared with when a general target such as old person was used), and (d) a between-subjects design (compared with a within-subjects design) was used. These results support Lutsky's (1981) conclusion that age, in and of itself, seems to be less important in determining attitudes toward the elderly than other types of information. The methodological limitations within the literature and a need to consider multiple components of attitudes toward older individuals are discussed.  相似文献   
106.
We investigated longitudinally the effects of a stroke on the social support systems and well-being of the patient's primary support person, both acutely and as the condition stabilized. Individuals who had suffered a first stroke and a primary support person participated in two waves of data collection, carried out in 6-month intervals beginning 7 weeks after the stroke. Our data show that the prevalence of depressive symptoms is from 2 1/2 to 3 1/2 times higher than rates found among representative samples of middle-aged and elderly populations. Mean level of depression did not change over time, although level of optimism declined significantly. Multiple regression analyses showed that levels of depression and perceived burden in support persons are highly related to aspects of the stroke such as its severity, and that demographic variables such as age and income play a relatively minor role in attenuating these relations in the acute adjustment phase. However, from 7 to 9 months after the stroke, well-established demographic variables such as health, income, and age were significant predictors of depression. Individuals who were older and who had good health and higher incomes were least depressed.  相似文献   
107.
The present study was designed to assess whether the conversational behavior of children separated into accepted, rejected, and mixed-status dyads differed along the dimensions of listening to, paying attention to, and indicating interest in their dyadic partner. Conversations of 40 third-grade dyads were analyzed as they occurred in a 2- min waiting period and a 4- min conversation period. Seventeen categories of verbal behaviors that indexed these dimensions were used as content codes. Multivariate analyses of variance performed on the observational data yielded significant main effects for status, sex, and experimental condition. Results are interpreted in terms of previous social skills research, and suggestions for future research are offered.  相似文献   
108.
Clinical judgments on the treatability and prognosis of mentally disordered offeenders (MDO) may strongly influence legal dispositions and the availability of treatment resources. This study examined 1,238 discharge summaries for MDOs referred for court assessments. Psychiatrists evidenced marked variability in how often they recommended treatment and how frequently they judged patients to have a poor prognosis. Two logit analyses suggested that diagnosis and consultation by other clinicians were associated with (a) treatment recommendations (i.e., Axis I diagnosis and social work consultations) and (b) prognosis (i.e., Axis II diagnosis and psychology consultations).  相似文献   
109.
110.
A software package called PAST (Programmer Assessment Software Tools) is described. PAST was designed as a research and diagnostic tool to analyze how programmers develop and test program code. PAST uses line changes between successive compiles to estimate a programmer’s cognitive processing. Line changes are highlighted and graphically presented between any two versions or compiles. Summary graphs and statistics across all versions also are provided. Applications of PAST for expanding our understanding of programming and applying it to research, teaching, and learning are discussed.  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