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   2821篇
  免费   136篇
  2957篇
  2023年   20篇
  2022年   26篇
  2021年   40篇
  2020年   57篇
  2019年   46篇
  2018年   87篇
  2017年   79篇
  2016年   84篇
  2015年   56篇
  2014年   60篇
  2013年   290篇
  2012年   138篇
  2011年   109篇
  2010年   83篇
  2009年   72篇
  2008年   101篇
  2007年   100篇
  2006年   87篇
  2005年   83篇
  2004年   67篇
  2003年   81篇
  2002年   74篇
  2001年   54篇
  2000年   75篇
  1999年   41篇
  1998年   44篇
  1997年   31篇
  1996年   26篇
  1994年   25篇
  1993年   26篇
  1992年   33篇
  1991年   49篇
  1990年   25篇
  1989年   34篇
  1988年   22篇
  1987年   25篇
  1986年   21篇
  1985年   30篇
  1982年   25篇
  1981年   31篇
  1980年   32篇
  1979年   27篇
  1978年   25篇
  1975年   33篇
  1974年   34篇
  1973年   26篇
  1972年   23篇
  1971年   21篇
  1968年   19篇
  1967年   19篇
排序方式: 共有2957条查询结果,搜索用时 15 毫秒
131.
31 college age men and women who consume less than three caffeinated beverages per week agreed to participate as subjects in research on the effects of acute caffeine intake on low intensity task performance. All subjects performed two randomly administered test conditions: (1) caffeine (5 mg/kg) and (2) placebo on separate visits following an initial 1-hr. orientation visit. Subjects were administered the beverage 30 min. prior to performing 12 separate tests assessing basic mathematics, simple response, logical reasoning, hand-eye coordination, and spatial and assembly skills. The Spielberger State Anxiety test was administered immediately after consuming the test beverage and once again at posttest. Analysis showed that caffeine did not significantly affect performance on all tests with the exception of the peripheral awareness (hand-eye coordination) test on which performance was higher after ingesting caffeine. The placebo treatment produced no effect on state anxiety, which contrasted with a significant rise in anxiety after caffeine consumption. State anxiety values were significantly greater after caffeine treatment relative to the placebo at pretest, and this difference persisted at posttest. These results demonstrated that the dose of caffeine increased scores on state anxiety for individuals who consumed less than three caffeinated beverages weekly but had very little effect on performance of low intensity tasks, except for a hand-eye coordination test involving peripheral awareness. Perhaps longer continuous performance of more demanding tasks would be more sensitive.  相似文献   
132.
The objective of this document is to provide health care professionals with recommendations for genetic counseling and testing of individuals with a suspected or confirmed diagnosis of Fabry disease, with a family history of Fabry disease, and those identified as female carriers of Fabry disease. These recommendations are the opinions of a multicenter working group of genetic counselors, medical geneticists, and other health professionals with expertise in Fabry disease counseling, as well as an individual with Fabry disease who is a founder of a Fabry disease patient advocacy group in the United States. The recommendations are U.S. Preventive Task Force Class III, and they are based on clinical experience, a review of pertinent English-language articles, and reports of expert committees. This document reviews the genetics of Fabry disease, the indications for genetic testing and interpretation of results, psychosocial considerations, and references for professional and patient resources. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. The professional judgment of a healthcare provider, familiar with the facts and circumstances of a specific case, will always supersede these recommendations.  相似文献   
133.
134.
Johnson DN 《Memory & cognition》2000,28(8):1303-1309
The effects of task demands on the representation of letter strings in long-term repetition priming (LTRP) were explored in two lexical decision experiments. The stimuli in both experiments were words and nonwords, some presented horizontally and some vertically. The only difference between the two experiments was the response required by the participant. In Experiment 1, the participants pressed one of two buttons, indicating whether or not a given stimulus was a word. In Experiment 2, the participants pressed one of four buttons, indicating both the lexical status and the orientation of a given stimulus. The results were that in Experiment 1, LTRP was not disrupted by a change in stimulus orientation, whereas in Experiment 2 it was, suggesting that the nature of the stimulus representation utilized in LTRP is partially dependent on the demands of the task.  相似文献   
135.
136.
This study assessed 37 children's and 38 adults', as well as their family members' (39 mothers and 26 spouses), coping responses to the news that they (or a loved one) were islet-cell antibody positive (ICA+) and at risk for type 1 diabetes. The Ways of Coping Checklist (WCC) was administered 4 months after ICA+ notification and at follow-up 10 months later. Participants' state anxiety was measured a few days after ICA+ notification and again 4 months later, at the time of the initial WCC administration. Children's coping strategies differed from those of adults, and mothers' coping strategies differed from spouses'. Initial state anxiety in response to ICA+ notification was related to how participants subsequently coped with the news. Coping, in turn, was related to maintenance of state anxiety over time.  相似文献   
137.
Two experiments tested the prediction based on the source monitoring framework that imagination is most likely to lead to false memories when related perceived events have occurred. Consistent with this, people were more likely to falsely remember seeing events when the events had been both imagined as seen and actually heard than when they were just heard, just visually imagined, or imagined both visually and auditorily. Furthermore, when people considered potential sources for memories or more carefully evaluated features of remembered events, source errors were reduced. On average, misattributed ("false") memories differed in phenomenal qualities from true memories. Taken together, these findings show that as different qualities of mental experience flexibly enter into source attributions, qualities derived from related perceptual events are particularly likely to lead to false claims that imagined events were seen, even when the event involves a primary modality (auditory) different from the target event (visual).  相似文献   
138.
Few cross-national reports have examined suicide rates among adolescents and young adults. A survey of suicides among 15-24-year-olds in 34 of the wealthiest nations demonstrated that 15,555 youths killed themselves in a 1-year study period. Thirty-four percent of these suicides were firearm-related. Finland led the participating nations in total and firearm-related suicide rates. An association was found between divorce rates and youth suicide rates, firearm-related suicide among youths, and suicide rates among young males. For a smaller sample of countries, an association was found between firearm availability and firearm-related suicide rates among youths and suicide rates among young males.  相似文献   
139.
Research on the hopelessness and self-esteem theories of depression (Abramson, Metalsky, & Alloy, 1989; Metalsky, Joiner, Hardin, & Abramson, 1993) suggests that HIV-infected persons with depressotypic attributional style (AS) and low self-esteem (SE) may be at risk for onset of a syndrome referred to as hopelessness depression (HD). In a prospective study conducted to test these theories, measures of anxiety and depression, AS, and SE were administered to 85 HIV+ and 43 HIV– men; symptoms were reassessed 6 months later. Results indicated that: (1) The interaction of AS, SE, and HIV status predicted change in HD symptoms, but not overall depression or anxiety symptoms; (2) HIV+ men with depressotypic AS and high SE had increased HD symptom levels while other men with high SE had decreased HD symptom levels; (3) HD symptoms remained stable over the 6-month interval among men with low SE; and (4) High SE predicted decreases in anxiety symptoms among HIV– men, but not among HIV+ men. Contrary to the study hypothesis, these findings suggest that among individuals with life-threatening illnesses such as HIV infection, those with depressotypic AS and high SE may be at highest risk for onset of HD.  相似文献   
140.
Summary and conclusions The health we seek is creative growth through all the relationships of life. We need an elastic concept of health, with a capacity to accept limitations and to do our best with these limitations in creative efforts to keep growing.We need to be aware of the particular hazards in this vocation, which may endanger the emotional health of the clergyman. Seeing these more clearly we can better prepare to cope with them.We must know to whom we belong, and learn to be at home with those persons and groups who become our living, working, and reciprocal community of outgoing care and forgiving love.If we can see emotional health as a dynamic process of ever-growing outreach and integration, we will value the stresses of our life and work. The pains as well as the joys contribute to the challenge and fulfillment of persons who grow through creative encounter with other persons.Continuing education will be needed for this crucial vocation of ministering to others, as it is in every serving profession where the complexities of life are so baffling. Academic courses and library study, though needed, will not suffice to prepare for effective work with other persons in face-to-face relations. There will be constant need for supervised evaluation of what we are and seek to become to others in the critical moments of meeting, listening, and responding as person to person in the ultimate concerns of our life in community.He is also a member of the Academy.  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