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   1860篇
  免费   109篇
  国内免费   1篇
  2020年   23篇
  2019年   19篇
  2018年   34篇
  2017年   36篇
  2016年   53篇
  2015年   42篇
  2014年   59篇
  2013年   303篇
  2012年   46篇
  2011年   40篇
  2010年   42篇
  2009年   56篇
  2008年   39篇
  2007年   31篇
  2006年   31篇
  2005年   21篇
  2004年   34篇
  2003年   27篇
  2002年   34篇
  2000年   19篇
  1999年   29篇
  1998年   27篇
  1997年   27篇
  1996年   25篇
  1994年   23篇
  1993年   33篇
  1992年   27篇
  1991年   28篇
  1990年   27篇
  1989年   31篇
  1988年   26篇
  1987年   20篇
  1986年   31篇
  1985年   22篇
  1984年   26篇
  1983年   27篇
  1982年   27篇
  1981年   31篇
  1980年   22篇
  1979年   31篇
  1978年   17篇
  1977年   18篇
  1976年   21篇
  1975年   17篇
  1974年   27篇
  1972年   17篇
  1969年   18篇
  1967年   19篇
  1966年   27篇
  1964年   17篇
排序方式: 共有1970条查询结果,搜索用时 15 毫秒
21.
Regional cerebral blood flow (rCBF) may be measured with inhalation techniques that use end-expired values of radioactivity to estimate the isotope concentration in arterial blood. These end-expired data are used as an input function in a mathematical equation to derive rCBF. End-expired air is assumed normally to be in equilibrium with the arterial blood at the alveolar surface of the lung during regular (passive) breathing; this assumption may not be valid during continuous phonation. We therefore have analyzed breathing (inhalation/exhalation) patterns and end-expired radioactivity (133Xe) during (1) speaking, (2) singing, and (3) humming of the national anthem, and also during (4) passive breathing. Statistically significant differences in breathing patterns were measured between a group of nonmusicians and two groups of musicians (singers) during the phonation tasks: The nonmusicians breathed more often (and more rapidly) and exhibited less variability in their breathing patterns than did the musicians. Notwithstanding these differences, the shapes of smoothed functions derived from the end-expired values were not influenced appreciably during phonation (except possibly during talking). The latter finding suggests that estimates of rCBF derived with these data should not be confounded seriously because of the continuous phonation.  相似文献   
22.
23.
Increasing numbers of Spanish-heritage immigrant families in the United States are beginning to seek therapy for family conflicts related to their adapation to the new country/culture. This paper focuses on the difficulties experienced by these families and presents issues specific to therapy with them. Effective therapy with these families requires that therapists focus on clarification of the differential adaptation rates of family members and facilitate a resolution of the family's transitional conflicts(s). Six cases involving such families are presented.David A. Baptiste, Jr., PhD, is a Psychologist and Marital and Family therapist in the counseling center at New Mexico State University and in private practice, Las Cruce, NM.Revision of a paper presented to the International Round Table for the Advancement of Counseling, Annual Conference, Utrech, The Netherlands, July, 1985. The author expresses appreciation to Judith Landau-Stanton for her helpful review of an earlier draft of this paper.  相似文献   
24.
In times of stress, men and women sometimes turn to the use of alcohol and drugs as an avenue for relieving their discomfort and distress. One explanation of this finding implicates traditional male tendencies as predisposing factors. The purpose of the present investigation was to study how the relationship between stress and substance use is moderated (1) by the masculine role, as measured by the Masculine Role Inventory; and (2) by socially desirable and undesirable masculine-instrumental and feminine-expressive personality attributes, as measured by the Extended Personal Attributes Questionnaire. The results indicated that during stressful episodes men characterized by socially undesirable instrumental personality attributes reported using tranquilizers and sedatives. By contrast, it was found that during stressful times, women characterized by success preoccupation reported less use of mind-altering drugs and more use of tranquilizers-sedatives. In addition, it was found that socially desirable expressive attributes served to buffer the impact of stressful experiences on women's use of alcohol.A preliminary report of these data were presented at the 1985 annual meeting of the Southwestern Psychological Association, Austin, Texas. Gratitude is extended to Toni Falbo for her assistance with this research.  相似文献   
25.
Pupillary responses have proven to be reliable physiological correlates of cognitive effort in a variety of tasks, including language processing. To investigate the relation between psychological and syntactic complexity 20 syntactically ambiguous sentences, balanced for bias, were presented to 16 subjects, while their pupil size was continuously measured. These sentences could be read as verb oriented (syntactically more complex) or object oriented (syntactically less complex). Principal components analysis of pupillary movements revealed that verb-oriented readings, resulted in greater pupillary dilations than object-oriented readings, indicating that syntactically more complex sentences, as determined via a formal grammar, require greater cognitive effort in processing. This is viewed as further evidence for the notion that syntactic and psychological complexity are related. High- and low-bias sentences did not induce comparable differences in pupillary movements, indicating that the "multiple meaning theory" may have to be modified.  相似文献   
26.
27.
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   
28.
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   
29.
Recent data on post-war birth cohorts in the U.S.A. show a negative relationship between IQ and fertility, both actual and expected. Previous investigators (e.g. Bajema, the Reeds and Waller) had found a slightly positive relationship for certain pre-war birth cohorts. This secular change in the relationship between IQ and fertility is replicated here for data on the membership of the American Mensa. Members born before the war exhibit a fertility below but close to that of the equivalent cohorts in the nation as a whole. Members born during and after the war exhibit a fertility that is substantially lower than that of the equivalent national cohorts. Apparently, rising fertility, which characterized the period in which the pre-war birth cohorts bore their children, causes a convergence in birth rates across IQ classes. Declining and/or low fertility, which characterizes the period in which the post-war birth cohorts are bearing their children, has the opposite effect, i.e. a divergence in birth rates across IQ classes, with the lower birth rates in the higher-IQ classes. The membership of Mensa may not be a representative sample of the high-IQ population as a whole, as it seems to attract a disproportionate number of low procreators even for this population. However, there is no reason to believe that changes in fertility rates across cohorts within Mensa, relative to changes in the national fertility rates, do not reliably reflect changes in fertility rates across cohorts within the high-IQ population of the U.S.A. as a whole, again relative to those of the nation, though these rates may be fluctuating around different means.  相似文献   
30.
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