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   9150篇
  免费   1654篇
  国内免费   1篇
  2023年   56篇
  2022年   64篇
  2021年   166篇
  2020年   199篇
  2019年   558篇
  2018年   468篇
  2017年   614篇
  2016年   606篇
  2015年   524篇
  2014年   480篇
  2013年   1247篇
  2012年   604篇
  2011年   525篇
  2010年   449篇
  2009年   383篇
  2008年   437篇
  2007年   333篇
  2006年   298篇
  2005年   353篇
  2004年   288篇
  2003年   286篇
  2002年   268篇
  2001年   166篇
  2000年   158篇
  1999年   119篇
  1998年   81篇
  1997年   64篇
  1996年   64篇
  1995年   39篇
  1994年   31篇
  1993年   51篇
  1992年   58篇
  1991年   50篇
  1990年   47篇
  1989年   45篇
  1988年   39篇
  1987年   42篇
  1986年   45篇
  1985年   47篇
  1984年   46篇
  1983年   40篇
  1982年   39篇
  1981年   29篇
  1980年   21篇
  1979年   29篇
  1978年   27篇
  1977年   28篇
  1976年   25篇
  1974年   20篇
  1973年   22篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
We distinguish three different readings of the intuitionistic notions of validity, soundness, and completeness with respect to the quantification occurring in the notion of validity, and we establish certain relations between the different readings. For each of the meta-logical notions considered we suggest that the most natural reading (which is not the same for all cases) is precisely the one which is required by the recent intuitionistic completeness theorems for IPC.This paper was partly written while the first author, H. C. M. de Swart, was a Visiting Fellow at Princeton University for the academic year 1976–1977. This opportunity was given to him by the Niels Stensen Stichting in Amsterdam, the department of philosophy of the Catholic University in Nijmegen and by Princeton University. He is happy to express his appreciation for that opportunity.  相似文献   
133.
The effects of task demands on the visual comparison of facial patterns and of comparable nonfacial patterns were explored in two studies. The studies yielded two primary findings. First, faces, despite their holistic properties, are not rotated faster than comparable non-face-like patterns, although subjects’ judgments of them were uniformly more rapid than judgments for nonfaces. Second, the nature of the same-different judgment task required of subjects had a large effect on the pattern of results obtained: When stimuli were compared to their mirror images, results indicative of mental “rotation” were obtained. When stimuli were compared on the basis of similarity of individual features, the pattern of results was very different. This one manipulation produced effects that exceeded those of all of the other manipulations, including that of rotation.  相似文献   
134.
Self-perceived competence in three roles (parent, social participant, self-supporter) was examined in relation to life satisfaction in a sample of 47 divorced, employed, single parent, middle-income women. Parenting was found to be the role of greatest perceived competence, and self-supporter the role of lowest perceived competence. Competence as a self-supporter was the strongest predictor of life satisfaction. Life satisfaction did not differ significantly between groups defined by length of time as single parents. For women separated less than 3 years, the social participant was the role of least perceived competence and the best predictor of life satisfaction. For those separated more than 3 years, the three roles were nearly equal in perceived competence, but competence as self-supporter was the best predictor of life satisfaction.  相似文献   
135.
136.
Twenty-one unassertive agoraphobic patients were assigned to one of three treatments: (1) prolonged exposure in vivo, (2) assertive training and (3) a combination of assertive training and prolonged exposure in vivo. Each treatment was conducted in groups which were led by two therapists. Assessments involved both phobic targets and assertiveness, and were made before and after treatment, and at 1-month follow-up. Exposure in vivo was found to be superior to assertive training on phobic targets. Assertive training produced greater gains in assertiveness than exposure in vivo. The combination of treatments produced results comparable to exposure in viro. Results indicated that the type of change produced by the treatments is a rather specific one and is related to the specific target of treatment.  相似文献   
137.
Seventy to 80 chronic psychiatric patients are treated in an aftercare clinic with a goal of tertiary preventive care. The major component of the treatment approach is reality-oriented group psychotherapy with an emphasis on interpersonal relationships. Attention to three factors in group psychotherapy with this population of patients has facilitated our work and outcome. These are the concept of the core group, diagnostic heterogeneity, and staff structure.  相似文献   
138.
In a study designed to assess the relationship between smoking status and correct identification of cigarette brands, junior high school students from two schools viewed cigarette and automobile advertisements with brand and model identification deleted. Results showed that adolescents with higher ad recognition scores were more likely to smoke cigarettes. In addition, a relationship was found between age and correct identification of cigarette advertisements, with older students identifying more ads correctly than younger students. No significant effects emerged for identification of automobile advertisements except for sex, with boys identifying more advertisements than girls. Additional findings indicated that even “experimental” smokers, who smoked as little as once per year, recognized significantly more cigarette advertisements than nonsmokers. These and other results are discussed in terms of their implications for prevention and policy issues. It is argued that society's allowance of printed cigarette advertising overlooks adolescents' heightened vulnerability to the kinds of appeals used in cigarette advertisements. Present policy also overlooks adolescents' relative unresponsiveness to the health risk information required in cigarette advertisements.  相似文献   
139.
Somatic complaints in anxious children   总被引:6,自引:0,他引:6  
Although stomachaches and headaches are considered characteristic of children with anxiety disorders, there is converging evidence that a broader range of somatic symptoms may be associated with children's expressions of anxiety. The purpose of this study was to determine the prevalence of somatic complaints in anxious children. The results indicated that children with anxiety disorders endorsed the presence of many different somatic complaints, and that contrary to clinical intuition, stomaches and headaches were not among the most commonly reported symptoms. In addition, the anxious children endorsed significantly more somatic complaints when compared to normal controls. Furthermore, the symptom pattern reported by anxious children indicated the presence of both the somatic and cognitive components usually associated with panic attacks, although none of the children met diagnostic criteria for panic disorder. The results are discussed in terms of the contribution of somatic symptoms to the understanding of anxiety disorders in children.  相似文献   
140.
Immediate post-training subcutaneous administration of lysine vasopressin (LVP, 0.003-1.00 microgram/kg) enhanced retention, whereas the vasopressin antagonist AAVP (0.01-0.30 microgram/kg) impaired it, in male Swiss mice tested 48 h after training in an inhibitory avoidance task. Both effects were dose-dependent. Neither LVP nor AAVP affected response latencies in mice not given the footshock on the training trial. The simultaneous administration of AAVP at a dose (0.01 microgram/kg) which had no effect on retention shifted the dose-response curve of LVP to the right. Nicotine (1.0-30.0 micrograms/kg, sc), a central nicotinic cholinergic agonist, also facilitated retention in a dose-related manner without affecting the retention performance of unshocked mice. The effect of nicotine was prevented by the central acting nicotinic cholinergic receptor antagonist mecamylamine (5 mg/kg, sc.). In contrast, neither hexamethonium (5 mg/kg, sc), a peripheral acting nicotinic receptor blocker, nor atropine (0.5 mg/kg, sc) or methylatropine (0.5 mg/kg, sc), two anticholinergic drugs which are known to act on muscarinic cholinergic receptors, prevented the effect of post-training nicotine. The effects of LVP and nicotine were time-dependent, suggesting that both treatments enhanced retention by influencing post-training processes involved in memory storage. Low doses of nicotine (1.50 microgram/kg, sc) or the central anticholinesterase physostigmine (35 micrograms/kg, sc) and LVP (0.003 microgram/kg, sc), which had no effect on retention when administered alone, produced a synergistic interaction when given together following training. The influence of LVP (0.03 microgram/kg, sc) on retention was prevented not only by AAVP (0.01 microgram/kg, sc) but also by mecamylamine (5 mg/kg, sc), whereas the effects of nicotine (10.0 micrograms/kg, sc) were prevented only by mecamylamine. These results suggest that the enhancement of retention induced by vasopressin is probably due to an activation of central nicotinic cholinergic mechanisms which are critical for memory formation.  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