全文获取类型
收费全文 | 50628篇 |
免费 | 2157篇 |
国内免费 | 34篇 |
出版年
2020年 | 578篇 |
2019年 | 638篇 |
2018年 | 982篇 |
2017年 | 910篇 |
2016年 | 1008篇 |
2015年 | 661篇 |
2014年 | 860篇 |
2013年 | 3852篇 |
2012年 | 1570篇 |
2011年 | 1622篇 |
2010年 | 927篇 |
2009年 | 1064篇 |
2008年 | 1398篇 |
2007年 | 1406篇 |
2006年 | 1260篇 |
2005年 | 1111篇 |
2004年 | 1077篇 |
2003年 | 1013篇 |
2002年 | 984篇 |
2001年 | 1724篇 |
2000年 | 1702篇 |
1999年 | 1281篇 |
1998年 | 536篇 |
1997年 | 504篇 |
1995年 | 482篇 |
1992年 | 1029篇 |
1991年 | 945篇 |
1990年 | 983篇 |
1989年 | 901篇 |
1988年 | 871篇 |
1987年 | 809篇 |
1986年 | 824篇 |
1985年 | 912篇 |
1984年 | 735篇 |
1983年 | 647篇 |
1982年 | 509篇 |
1979年 | 758篇 |
1978年 | 558篇 |
1977年 | 492篇 |
1976年 | 494篇 |
1975年 | 625篇 |
1974年 | 751篇 |
1973年 | 777篇 |
1972年 | 649篇 |
1971年 | 550篇 |
1970年 | 495篇 |
1969年 | 534篇 |
1968年 | 676篇 |
1967年 | 593篇 |
1966年 | 606篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Fluid intelligence belongs to that cluster of intellectual abilities evincing aging loss. To examine further the range of intellectual reserve available to aging individuals and the question of replicability in a new cultural and laboratory setting, 204 healthy older adults (mean age = 72 years; range = 60-86) participated in a short-term longitudinal training study. For experimental subjects, 10 sessions consisted of cognitive training involving two subability tests (Figural Relations, Induction) of fluid intelligence. The pattern of outcomes replicates and expands on earlier studies. Older adults have the reserve to evince substantial increases in levels of performance in fluid intelligence tests. Transfer of training, however, is narrow in scope. Training also increases accuracy of performance and the ability to solve more difficult test items. Difficulty level was estimated in a separate study, with a comparable sample of N = 112 elderly adults. Future research is suggested to examine whether intellectual reserve extends to near-maximum levels of performance. 相似文献
992.
Short scales were developed to measure three broad dimensions of personality in the National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Followup Study. Items to measure neuroticism were selected rationally from the General Well-Being Schedule, and items to measure extraversion and openness to experience were selected by multiple regression from the NEO Personality Inventory. In a sample of 654 men and women from the Augmented Baltimore Longitudinal Study of Aging, all three short scales showed clear evidence of convergent and discriminant validity against full scales in self-reports, and against peer and spouse ratings. Because they were developed and validated on a sample with a comparable age range, the NHANES scales should be useful in examining age trends in these three personality dimensions in a national sample. 相似文献
993.
Barbara E. DiCocco L.C.S.W. 《Contemporary Family Therapy》1986,8(1):50-61
When presented with a behavioral problem or symptom expression that involves two systems, such as a serious school-related problem, the therapist needs to design an approach that will intervene effectively and expeditiously in both systems. This paper offers a guide to stages of problem escalation and therapeutic intervention that is intended to aid the problem-solver's thinking processes in approaching a troubled situation that involves two systems, the school and the home. 相似文献
994.
995.
There has been interest in recent years in the relationship between marital distress and psychopathology. It has been rare, however, for investigators to follow patients after their release from the hospital and observe the course of their marital relationships. The present study included patients meeting criteria for three DSM III DISORDERS (MAjor depressive, bipolar, and schizophrenic) and a normal control sample, all of whom are participants in an ongoing longitudinal study of children at risk for psychopathology (Stony Brook High-Risk Project; Weintraub & Neale, 1984). Marital Adjustment Test (MAT; Locke & Wallace, 1959) scores were collected on patients at entry into the project (Phase I) and at a three year follow-up (Phase II). Course of marriage was defined as negative if the couple's marital adjustment was rated as poor at Phase II or resulted in divorce or separation at Phase II. It was found that only the depressed group differed from the normal group in having significantly worse course of marital relationship; 84% of the depressive couples showed a “negative” course of marital change over time. However, all three patient groups had significantly higher rates of divorce by Phase II. MAT scores at Phase I successfully predicted course of marital relationship for all diagnostic groups. Implications for aftercare of psychiatric inpatients are discussed. 相似文献
996.
Alternate monocular and binocular exposure to complementary stimulation can yield opposite but coexisting aftereffects that are contingent on whether the test display is viewed with one eye or two eyes. The motion aftereffect was studied by adapting each eye separately to a contracting spiral and both eyes together to an expanding spiral. The stationary test spiral subsequently appeared to be expanding when viewed monocularly, but to be contracting when it was seen with both eyes open. With respect to the McCollough effect, after monocular exposure to red-vertical and green-horizontal gratings and binocular exposure to red-horizontal and green-vertical gratings, the appearance of the color of the test gratings when viewed with one eye was different from that when viewed with both eyes. Opposite, coexisting aftereffects induced by complementary stimulation can be interpreted as evidence that there are unique binocular aspects to visual function. 相似文献
997.
Howard C. Hughes 《Attention, perception & psychophysics》1984,36(2):177-184
It is well established that human observers respond more quickly to visual targets that appear in expected locations than they do to ones in unexpected locations. These variations in simple reaction time have been attributed to a covert alignment of an attentional mechanism to the expected target location. The present experiments investigated the influence of strength of signal and strength of subject’s positional expectancy on the magnitude of this attentional effect. In the first experiment, target luminance was varied over a range of three log units, and it was found that the effects of luminance were essentially additive with the effect of the positional expectancy (i.e., the attention effect). The second experiment found that the magnitude of visual attention interacts with the information value of the precue used to create the spatial expectancy, although, once again, luminance had additive effects. The resuls are interpreted as indicating that, rather than influencing early visual processing, the act of attending to a spatial location operates fairly late in the detection process. 相似文献
998.
A. H. C. van der Heijden R. Schreuder L. Maris M. Neerincx 《Attention, perception & psychophysics》1984,36(6):577-585
This study investigates the separate activation versus coactivation issue for redundant targets in a simple letter-detection paradigm with latency as the dependent variable. The results of a one-response visual-search task are reported. Since, on single-target trials, only the target was presented and no accompanying noise element, no “distraction decrement” caused by irrelevant noise elements (Grice et al., 1984) was to be expected. The data obtained showed a clear redundantsignal effect. Subsequent detailed analysis of the latency data using Miller’s (1982) procedure indicated that the results were consistent with a separate activation model and failed to provide convincing evidence in favor of coactivation models. A further analysis of the data indicated that, in the present study, the separate channels were negatively correlated for a range of fast RTs and positively correlated for intermediate and larger RTs. No evidence in favor of Grice et al.’s (1984) distraction-decrement hypothesis was found. The conclusions of this study are that (1) a separate activation model summarizes the essential features of information processing in this simple visual search task, and (2) no convincing evidence in favor of coactivation in visual search tasks has been reported in the literature up to now. 相似文献
999.
A sample of delinquent and nondelinquent male adolescents was assessed with respect to locus of control and intellectual achievement responsibility. Data were also gathered concerning age, family size, birth order, socioeconomic status, race, and school grade. Results were subjected to a multivariate analysis and showed support for a multidimensional model of locus of control. There was no difference in expectancy of control for negative academic events between delinquents and nondelinquents. In general, birth order and delinquency were the two most important determinants of locus of control. Results are discussed in terms of previous literature on locus of control with particular consideration paid to expectations of control. 相似文献
1000.
The present study examined some previously reported relationships between drug use by adolescents and perceived attitudes and behaviors of their parents. An anonymous questionnaire was administered to the student body of an inner-city secondary school for difficult students. Relationships between parental use of drugs and adolescent use of the same drugs were moderate and roughly equivalent across drugs. However, parental use of marijuana was strongly related to the adolescent's use of other, harder drugs such as opiates, cocaine, amphetamines, and barbiturates. This finding is explained within the framework of Kandel's postulated stages of drug initiation. It points to a need for further study of parental influences, which may be increasingly problematic as more individuals who have grown up in our marijuana-accepting society become parents of adolescents. 相似文献