全文获取类型
收费全文 | 51796篇 |
免费 | 2142篇 |
国内免费 | 19篇 |
出版年
2020年 | 532篇 |
2019年 | 641篇 |
2018年 | 915篇 |
2017年 | 905篇 |
2016年 | 927篇 |
2015年 | 634篇 |
2014年 | 845篇 |
2013年 | 3801篇 |
2012年 | 1514篇 |
2011年 | 1638篇 |
2010年 | 935篇 |
2009年 | 1003篇 |
2008年 | 1428篇 |
2007年 | 1412篇 |
2006年 | 1323篇 |
2005年 | 1162篇 |
2004年 | 1143篇 |
2003年 | 1067篇 |
2002年 | 1069篇 |
2001年 | 1678篇 |
2000年 | 1590篇 |
1999年 | 1224篇 |
1998年 | 599篇 |
1997年 | 507篇 |
1992年 | 976篇 |
1991年 | 908篇 |
1990年 | 943篇 |
1989年 | 895篇 |
1988年 | 869篇 |
1987年 | 810篇 |
1986年 | 851篇 |
1985年 | 945篇 |
1984年 | 749篇 |
1983年 | 684篇 |
1982年 | 550篇 |
1981年 | 511篇 |
1979年 | 801篇 |
1978年 | 601篇 |
1977年 | 493篇 |
1976年 | 528篇 |
1975年 | 698篇 |
1974年 | 794篇 |
1973年 | 817篇 |
1972年 | 644篇 |
1971年 | 590篇 |
1970年 | 560篇 |
1969年 | 601篇 |
1968年 | 741篇 |
1967年 | 643篇 |
1966年 | 657篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
T R Zentall P Jackson-Smith J A Jagielo G B Nallan 《Journal of experimental psychology. Animal behavior processes》1986,12(2):153-159
Categorical coding is the tendency to respond similarly to discriminated stimuli. Past research indicates that pigeons can categorize colors according to at least three spectral regions. Two present experiments assessed the categorical coding of shapes and the existence of a higher order color category (all colors). Pigeons were trained on two independent tasks (matching-to-sample, and oddity-from-sample). One task involved red and a plus sign, the other a circle and green. On test trials one of the two comparison stimuli from one task was replaced by one of the stimuli from the other task. Differential performance based on which of the two stimuli from the other task was introduced suggested categorical coding rules. In Experiment 1 evidence for the categorical coding of sample shapes was found. Categorical color coding was also found; however, it was the comparison stimuli rather than the samples that were categorically coded. Experiment 2 replicated the categorical shape sample effect and ruled out the possibility that the particular colors used were responsible for the categorical coding of comparison stimuli. Overall, the results indicate that pigeons can develop categorical rules involving shapes and colors and that the color categories can be hierarchical. 相似文献
942.
Sex differences in the effects of gonadectomy on amphetamine-induced rotational behavior in rats 总被引:2,自引:0,他引:2
The effects of gonadectomy on amphetamine-induced rotational behavior were studied in male and female rats. Different systemic doses were used to produce equivalent brain concentrations of the drug in each group, thereby controlling for sex differences in the metabolism of amphetamine. Ovariectomy of female rats significantly attenuated amphetamine-induced rotation, whereas castration of males was without effect. The results support the idea that in females, the endogenous gonadal hormones facilitate functional activity in the mesostriatal dopamine system. 相似文献
943.
Glucose modulation of memory storage processing 总被引:9,自引:0,他引:9
P E Gold 《Behavioral and neural biology》1986,45(3):342-349
Epinephrine, derived from the adrenal medulla, enhances memory storage for several forms of learning. One physiological action of this hormone is to liberate hepatic glucose stores. This experiment tested the possibility that glucose could itself enhance memory. Rats were water deprived, pretrained to drink, pretrained to drink in the behavioral apparatus, and then trained in a one-trial inhibitory (passive) avoidance task. Immediately after the training footshock, the animals each received an injection of glucose (1.0-500 mg/kg). When tested for retention 24 h later, the animals which received 10 or 100 mg/kg doses of glucose exhibited enhanced retention performance; higher and lower doses had no significant effect on the memory tests. Also, glucose injections (100 mg/kg) delayed by 1 h after training had no effect on the retention tests. These findings suggest that the increase in plasma glucose levels subsequent to epinephrine injection may contribute to the effects of epinephrine on memory. In addition, the results suggest that peripheral glucose levels may exert important influences on memory storage. 相似文献
944.
The psychometric properties of the State-Trait Anxiety Inventory for Children (STAIC) and relationships between STAIC T-Anxiety scores and standardized measures of achievement were determined for 948 kindergarten and first-and second-grade children. The T-anxiety scores of kindergarten children were lower than those of first-and second-graders. Internal consistency of the STAIC scales was higher in individual testing sessions than in small group administrations. Small but significant negative correlations were found between STAIC T-Anxiety scores and measures of school achievement. It was concluded that the STAIC is a potentially useful measure of state and trait anxiety in kindergarten through sixth-grade children, but it must be administered individually at the kindergarten and first-grade levels.The research was performed while the senior author was a senior research scientist at the Dallas Independent School District. 相似文献
945.
Health as a value: methodological and theoretical considerations 总被引:8,自引:0,他引:8
The concept of value placed on health is very important in several different theoretical approaches to the study of health behavior. In practice, however, health value is generally assumed to be universally high rather than being directly measured. If this assumption is incorrect, then theories that include health value have rarely been adequately tested. This paper presents a short 4-item Likert scale designed to measure the value placed on health. Norms from the utilization of this scale in five different samples are presented. Health value is found to increase with age among girls, but the increase apparently stops by late adolescence, before full adult levels of health value are achieved. Middle-aged women place a higher value on health than do middle-aged men, although no comparable sex difference appears in a sample of undergraduates. Consistent with theoretical predictions, both health locus of control beliefs and beliefs in the efficacy of certain preventive health behaviors correlate more highly with the performance of those same behaviors 5 to 9 months later among respondents who place a high value of health relative to those who do not value health so highly. However, this interaction is found only when it can be safely assumed that health is the primary value underlying the behavior. The importance of considering a variety of values in addition to health as possible motivators of preventive health behavior is stressed. 相似文献
946.
947.
948.
RICHARD E. PRICE MICHAEL M. OMIZO VICTORIA L. HAMMETT 《Journal of counseling and development : JCD》1986,65(2):96-97
The authors discuss issues and suggestions relative to counseling clients with AIDS. Several psychosocial issues are presented, and a psycho-educational model of treatment to meet the needs of AIDS clients is described. 相似文献
949.
MARY K. O'FARRELL CLARA E. HILL SUSAN M. PATTON 《Journal of counseling and development : JCD》1986,65(3):141-145
Process analyses revealed that interpretations and exploration of feelings were helpful across two cases. Other interventions were helpful for one case but not the other. 相似文献
950.
Daniel N. Klein Richard A. Depue Steven P. Krauss 《Journal of psychopathology and behavioral assessment》1986,8(4):355-366
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