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   32525篇
  免费   567篇
  国内免费   3篇
  2020年   162篇
  2019年   165篇
  2018年   3723篇
  2017年   3024篇
  2016年   2476篇
  2015年   380篇
  2014年   288篇
  2013年   983篇
  2012年   932篇
  2011年   2785篇
  2010年   2746篇
  2009年   1693篇
  2008年   2045篇
  2007年   2491篇
  2006年   335篇
  2005年   460篇
  2004年   394篇
  2003年   327篇
  2002年   283篇
  2001年   462篇
  2000年   470篇
  1999年   308篇
  1998年   141篇
  1997年   116篇
  1996年   118篇
  1995年   109篇
  1992年   226篇
  1991年   236篇
  1990年   228篇
  1989年   217篇
  1988年   217篇
  1987年   206篇
  1986年   195篇
  1985年   195篇
  1984年   179篇
  1983年   133篇
  1982年   133篇
  1979年   167篇
  1978年   125篇
  1977年   116篇
  1975年   160篇
  1974年   169篇
  1973年   192篇
  1972年   166篇
  1971年   155篇
  1970年   132篇
  1969年   142篇
  1968年   188篇
  1967年   145篇
  1966年   153篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
241.
A variety of studies withhabitual users of nicotine, caffeine, cocaine, and amphetamines have shown that administration of these stimulants has the paradoxical effect of lowering arousal states. Research on transmarginal inhibition shows that when subjects are presented with a succession of stimuli monotonically increasing in intensity, GSR and related arousal responses increase first and then begin to decline beyond a certain point of stimulus intensity. That is, following repeated exposure to intense stimuli, continued more intense stimulation has the effect of lowering arousal. Since stimulants subjectively heighten stimulus intensity, the transmarginal inhibition data provide a basis for explaining opposing effects of stimulants on arousal, depending on dose and frequency of use. It was hypothesized that when dose levels are low and usage is infrequent, arousal increases with stimulant intake. In contrast, when dose levels are high and frequent, arousal shows decrements with new intakes of stimulant. A new questionnaire measure of characteristic arousal was developed and correlated with subjects' reports of habitual levels of stimulant and sedative intake. Weekly total stimulant use correlated significantly and negatively with characteristic arousal level, providing support for the hypothesis. This lowered arousal of frequent stimulant users was not a confound of, or due to, concomitant frequent sedative use, since total stimulant and sedative use levels were uncorrelated.The author would like to thank Janice Schafrik for running the subjects in this study.  相似文献   
242.
Despite speculation that sucrose consumption affects behavior, little empirical information is available. Accordingly, this study investigated the effect of sucrose consumption on the behavior of eight preschool children. Children were tested individually using a double-blind, crossover design. On separate mornings each child received 6 ounces of juice, sweetened on one morning with sucrose and on the other with an artificial sweetener. Children were observed for 90 minutes following the drinks, alternating between 15-minute sessions of work on structured tasks and 15-minute sessions of free play. Following the sucrose drink the children showed a decrement in performance in the structured testing situation, and they demonstrated more inappropriate behavior during free play. These differences in behavior were most pronounced approximately 45 to 60 minutes after the drinks. Thus, the study provides objective evidence in young children of a rather subtle, yet significant, time-dependent behavior effect of sucrose ingestion.This research was funded in part by grants from the General Research Grants Committee, University Hospital, Boston University Medical Center, and from the University of Connecticut Research Foundation. The project was conducted at the Clinical Research Center, Massachusetts Institute of Technology (National Institute of Health/General Clinical Research Center Grant 5M01-RR00088-20). We would like to express our appreciation to the many staff members of the Clinical Research Center for their extensive cooperation in helping us to plan and carry out this study, and to the director and staff of Technology Children's Center for their assistance in helping us to reach interested families. We also would like to thank the parents and children who participated in the study. Portions of this paper were presented at the annual meeting of the American Psychological Association, Toronto, August 1984.  相似文献   
243.
Attitudes toward posthumous organ donation and commitment to donate   总被引:4,自引:0,他引:4  
The medical need for human organs suitable for use as transplants far exceed the supply, and is growing. More favorable attitudes about organ donation would increase people's willingness to sign posthumous donation pledges. But effective educational programs require information about the public's present views. Verbal attitude scales were constructed and administered to 110 adults, resulting in reliable measurement of two independent dimensions, prodonation and antidonation (r = .003). Cluster analysis of the instrument revealed that the positive dimension involves belief in the humanitarian benefits of organ donation and feelings of pride experienced by the donor. The negative dimension reflects fears of body mutilation and of receiving inadequate medical treatment when one's life is at risk. Pro and anti scores in combination predicted willingness to sign a donor card. A 2 X 2 analysis of variance (High-Low Positive X High-Low Negative) revealed significant main effects for both positive and negative attitude. Also, a significant interaction effect was obtained. Those subjects who had both strong positive attitudes and weak negative attitudes were especially willing to sign donor cards. Suggestions for designing educational campaigns to promote organ donation are offered.  相似文献   
244.
Self-disclosure patterns of Anglo-Americans and Mexican Americans were analyzed according to overall frequency of reported self-disclosure and preferred targets (i.e., mother, father, male friend, female friend). Administrator sex and ethnicity were systematically varied so that the interaction of these variables with participant sex and ethnicity could be investigated. Results revealed that Anglo-Americans reported the most disclosure and Mexican-American men the least. Some suggestions are provided for counselors working with Mexican-American men.  相似文献   
245.
Psychopathology and symptom patterns were studied in 60 former prisoners-of-war (POWs) by administering standardized tests including the Minnesota Multiphasic Personality Inventory (MMPI), an adjustment problem checklist, and a structured clinical interview. Most POWs showed marked psychological impairment, but modal profile analysis identified two prototypic MMPI patterns, which differed in pervasiveness and type of psychopathology. Profile subtypes were defined by unique clusters of clinical symptoms and differed in confinement stress severity. The typology of symptoms argues against a homogeneous conceptualization of stress-induced disorders and suggests the need for definition of the severity and subtype of stress phenomena and individual difference factors in responding to trauma.  相似文献   
246.
This study investigated the relationship among anger, the Type A construct, and cardiovascular reactivity. The Novacco Anger Scale and the Jenkins Activity Survey (JAS) were used to measure anger proneness and Type A characteristics, respectively. Twenty-four college males were selected from the upper and lower quintiles of the JAS distribution. During the study, the subjects were exposed to varying levels of experimentally induced challenge, while measurements were taken of heart-rate and blood-pressure changes. The results showed a modest but significant correlation between scores on the Novacco Anger Scale and the JAS. More importantly, scores on the Novacco Anger Scale correlated significantly with heart rate and systolic blood pressure under all challenge conditions, while those on the JAS were unrelated to cardiovascular excitability. These results raise questions about the usefulness of the JAS as a predictor of CHD risk. They are also consistent with the beliefs of other investigators that anger and hostility are the most important Type A behaviors in predisposing patients to coronary heart disease. Additional implications of the study are discussed.  相似文献   
247.
The social adjustment of the adolescent offspring of parents with bipolar affective disorder (n=41) was compared to that of the offspring of parents with nonaffective psychiatric disorders (n=22) and the offspring of normal controls (n=26). In addition, the relationship between social adjustment and cyclothymia in offspring was determined. Social adjustment was assessed using the Life Activities Inventory, a new measure developed to assess social functioning in adolescents and young adults. Cyclothymia was assessed with the General Behavior Inventory. As a group, the offspring of bipolar parents did not differ significantly from either control group on social adjustment. However, the cyclothymic offspring of bipolar parents exhibited significantly poorer social adjustment than the noncyclothymic offspring of bipolars and the offspring of psychiatric and normal controls. These findings suggest that poor social functioning in the adolescent offspring of parents with bipolar illness may be associated with the early manifestations of affective disorder. In addition, these data indicate that despite its subsyndromal intensity, cyclothymia can result in significant social impairment.This study was supported in part by National Institute of Mental Health (NIMH) Research Grant MH-39782 to Daniel N. Klein and NIMH Grants MH-33083 and MH-37195 to Richard A. Depue.  相似文献   
248.
Factors affecting spontaneous alternation behavior (SAB) in animals, for example, age, gender and species studied; type of apparatus and cues employed; and neuro-anatomical, neuro-chemical and motivational status of the organism, were reviewed. Despite a myriad of experiments showing interesting main effects of such variables, little research has been performed assessing the interactive affects of these factors on alternation behavior. For example, psychologists test rats in central nervous system (CNS) lesion studies, whereas psychopharmacologists tend to assess SAB in mice. Most importantly, studies have not been reported investigating the possible interactions among species, brain lesions and drugs. This is an unfortunate omission since several important alternation models include propositions relating to cholinergic and/or serotonergic coding in the hippocampus. Examination of behavioral studies revealed the primary cue for alternation among invertebrates to be body turn, whereas vertebrates rely primarily on directional and odor cues. Reference to the seeking of stimulus change remains the most compelling motivational account of why animals manifest this ubiquitious and reliable behavior pattern. This review and the unpublished studies were supported by Research Grants MH16962, MH21288, and MH36491 from the National Institute of Mental Health and the Wake Forest University Research and Publication Fund.  相似文献   
249.
This paper reviews the literature on scapegoating, elaborating on the underlying mechanisms before describing the process of scapegoating as it occurred in a neonatal nurse support group. Illustrative vignettes are used to discuss how scapegoating was used by group members to avoid painful feelings arising from their care of extremely ill infants. Group process is related to the stages of the group's development as feelings were addressed more directly and the need to use scapegoating as a defense decreased.  相似文献   
250.
Gary N. Powell 《Sex roles》1986,14(1-2):9-19
Individuals' own definitions of sexual harassment ultimately influence the success of their companies in responding to the Equal Employment Opportunity Commission's (EEOC) guidelines against sexual harassment. Previous research has consistently shown that women see more sexual harassment than do men. However, sex differences in definitions of sexual harassment could be explained by sex role identity. Results from a study of undergraduate business students and MBA students holding full-time jobs instead reaffirmed the existence of a sex effect and revealed the presence of a Sex X Masculinity interaction effect. Subjects' femininity had a minor effect on their definitions of sexual harassment.A previous version of this article was presented at the Academy of Management Meeting, Dallas, August, 1983. Appreciation is extended to Lisa A. Film for her assistance with data analysis.  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