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   1680篇
  免费   68篇
  2023年   10篇
  2021年   26篇
  2020年   28篇
  2019年   29篇
  2018年   27篇
  2017年   50篇
  2016年   45篇
  2015年   32篇
  2014年   35篇
  2013年   174篇
  2012年   91篇
  2011年   86篇
  2010年   46篇
  2009年   60篇
  2008年   73篇
  2007年   58篇
  2006年   65篇
  2005年   61篇
  2004年   55篇
  2003年   51篇
  2002年   52篇
  2001年   30篇
  2000年   29篇
  1999年   22篇
  1998年   31篇
  1997年   22篇
  1996年   13篇
  1995年   15篇
  1994年   25篇
  1993年   22篇
  1992年   21篇
  1991年   22篇
  1990年   27篇
  1989年   27篇
  1988年   14篇
  1987年   17篇
  1986年   18篇
  1985年   21篇
  1984年   15篇
  1983年   21篇
  1982年   20篇
  1981年   12篇
  1980年   15篇
  1979年   14篇
  1977年   11篇
  1976年   16篇
  1975年   9篇
  1971年   9篇
  1968年   10篇
  1967年   9篇
排序方式: 共有1748条查询结果,搜索用时 15 毫秒
1.
There is substantial evidence of detrimental psychological sequelae following disasters, including terrorist attacks. The effect of these events on extreme responses such as suicide, however, is unclear. We tested competing hypotheses about such effects by employing autoregressive integrated moving average techniques to model the impact of September 11 and the Oklahoma City bombing on monthly suicide counts at the local, state, and national level. Unlike prior studies that provided conflicting evidence, rigorous time series techniques revealed no support for an increase or decrease in suicides following these events. We conclude that while terrorist attacks produce subsequent psychological morbidity and may affect self and collective efficacy well beyond their immediate impact, these effects are not strong enough to influence levels of suicide mortality.  相似文献   
2.
3.
A national survey was conducted to compare the background and career characteristics of men and women engineers differing in the number of years since they completed their BS degrees (0–5, 6–10, 11–15, and 16–20 years). The parents of women engineers were more likely to have college degrees and to be employed in professional positions than were the parents of men engineers. Women engineers were less likely to be married and were more likely to be childless than were the men. Both men and women were influenced by courses and work–related factors in their decisions to pursue engineering, but men made their career decisions sooner than women. Although men and women reported comparable levels of technical responsibility in their present jobs, gender differences favoring men were found for supervisory responsibility and salary among those with more than five years of experience, with the gap between men and women increasing with experience. Men with 16–20 years of experience and all four degree cohorts of women endorsed the opinion that there are better opportunities for men than women in engineering.  相似文献   
4.
5.
6.
This study examined the relationship of reported maternal depression to prior and current life stressors, and to mother perceptions of child adjustment, parenting behaviors, and child conduct problems. Forty-six depressed mothers and 49 nondepressed mothers and their clinic-referred children (aged 3-8 years) participated. Depressed mothers were more critical than nondepressed mothers, but the behavior of children of depressed and nondepressed mothers showed no significant differences. Depressed mothers were more likely to have experience child abuse, spouse abuse, or more negative life events than nondepressed mothers. Maternal reports of stress related to mother characteristics and to negative life events were the most potent variables discriminating depressed from nondepressed mother families.  相似文献   
7.
One hundred and thirty-three college students responded to percentage definitions of “good,” “minimal,” and “no” eye contact. They also judged their perceptions of a speaker with “little or no eye contact” on a semantic differential scale containing 60 polarized adjective pairs regarding personality traits. The majority of the student respondents defined an individual with “good” eye contact as looking at his/her audience/listener 90–100% of the time. This is a more stringent definition than other literature has indicated. Furthermore, speakers with little or no eye contact were judged less favorably on 70% of the items, which indicates that low eye contact adversely affects perceptions of a speaker's personality. Therefore, stutterers need to be made aware of the importance of and determinants of effective eye contact in communication. Also, the development of effective eye contact needs to be incorporated as a major goal in stuttering therapy.  相似文献   
8.
There is usually a long period of time between infection with the AIDS virus and manifestation of symptoms. Asymptomatic patients often would benefit from elective surgery for diseases such as arthritis which are unrelated to their infection. The surgeons' decisions to accept the risks to themselves, their spouses, and their operating teams in order to relieve pain and suffering appear to be based upon two covenants; one concerns their role within the doctor-patient relationship, and the other concerns their relationship to what they see as the ultimate meaning in life.  相似文献   
9.
Human fetal cardiac responses (36-39 weeks gestational age) to brief, repeated vocal stimuli (male or female voice uttering the same sentence), given at 90-95 dB SPL ex utero (around 20-30 dB less in utero) during a state of low fetal heart rate (FHR) variability, were examined using highly conservative statistical criteria taking into account each subject's prestimulus FHR variability. Subjects exposed to either of the two stimuli displayed significantly more decelerative heart rate (HR) changes compared to control subjects receiving no stimulation. The decelerative changes started during the first seconds following the onset of stimulation and reached their amplitude peak within 10 or 20 sec, depending on the subject. The directions—HR acceleration or deceleration—and the amplitude of the response depended on prestimulus HR variability only, not on prestimulus level. No major difference was found between the effects of the two voices. The data are compared to previous studies demonstrating fetal decelerative changes to acoustic stimuli of less than 105 dB SPL. The choice of an objective criterion to define an HR response and the possible orienting response nature of the decelerative change are discussed.  相似文献   
10.
Teams are playing an increasingly important role in the workplace. However, reviews of the team performance literature have suggested that there are serious deficiencies in our understanding of team processes and performance (e.g., Dyer, 1984). These difficulties may be attributable, in part, to the lack of laboratory methodologies to investigate team performance. This paper describes the use of low-fidelity simulations as a potentially useful paradigm for researching team coordination and performance. This paradigm is advantageous in that it offers relatively high levels of experimental control and task representation at a low cost.  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