全文获取类型
收费全文 | 37461篇 |
免费 | 1520篇 |
国内免费 | 29篇 |
专业分类
39010篇 |
出版年
2020年 | 375篇 |
2019年 | 484篇 |
2018年 | 716篇 |
2017年 | 658篇 |
2016年 | 766篇 |
2015年 | 503篇 |
2014年 | 606篇 |
2013年 | 2898篇 |
2012年 | 1189篇 |
2011年 | 1185篇 |
2010年 | 688篇 |
2009年 | 759篇 |
2008年 | 996篇 |
2007年 | 1016篇 |
2006年 | 899篇 |
2005年 | 805篇 |
2004年 | 788篇 |
2003年 | 716篇 |
2002年 | 760篇 |
2001年 | 1258篇 |
2000年 | 1255篇 |
1999年 | 919篇 |
1998年 | 386篇 |
1997年 | 360篇 |
1995年 | 368篇 |
1992年 | 741篇 |
1991年 | 706篇 |
1990年 | 687篇 |
1989年 | 640篇 |
1988年 | 631篇 |
1987年 | 578篇 |
1986年 | 596篇 |
1985年 | 638篇 |
1984年 | 537篇 |
1983年 | 487篇 |
1982年 | 366篇 |
1979年 | 571篇 |
1978年 | 402篇 |
1977年 | 375篇 |
1976年 | 375篇 |
1975年 | 429篇 |
1974年 | 538篇 |
1973年 | 568篇 |
1972年 | 481篇 |
1971年 | 422篇 |
1970年 | 398篇 |
1969年 | 421篇 |
1968年 | 522篇 |
1967年 | 458篇 |
1966年 | 441篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
Processing resources and age differences in working memory 总被引:1,自引:0,他引:1
This study investigated the performance of young and old subjects on a modified version of the working memory task developed by Baddeley and Hitch (1974). Subjects were required to verify a set of sentences of varying complexity while they repeated aloud zero, two, or four words. The older subjects took longer to verify the sentences, especially when the sentences were grammatically complex, but the effect of concurrent memory load on verification latency was the same in both groups. These results cast doubt on the notion that there is an age-related decline in one general pool of processing resources. They also suggest that older people have greater difficulty with the active processing aspects, rather than with the passive holding aspects, of working memory tasks. 相似文献
122.
The concept of heightened resilience or invulnerability in young profoundly stressed children is developed in terms of its implications for a psychology of wellness and for primary prevention in mental health. Relevant literature is reviewed, a skeletal model for studying resilience is outlined, and needed research directions are considered. The latter include expansion of the construct's nomological definitional net, inquiry into the antecedents and determinants of resilience, and the application of such generative information to frame preventive interventions for young, profoundly stressed children. 相似文献
123.
Selma A. Lewis Jim Johnson Patricia Cohen Marc Garcia Carmen Noemi Velez 《Journal of abnormal child psychology》1988,16(4):459-471
Twenty-six suicide attempters, 9 to 18 years of age, were compared with 725 nonattempters on measures of school achievement, educational goals, socioeconomic status, and depression. As has been found in studies using clinical samples, suicide attempters in our communitybased sample had significantly lower school achievement than nonattempters. The relationship between attempted suicide and low school achievement seemed to be explained by the effects of depression. Lower-SES youth tended to be more likely to attempt suicide than higher-SES youths. However, SES appeared to have little effect on the relationship between attempted suicide and school achievement. Results also suggest that children of mothers with low educational goals for them may be more at risk for attempted suicide than youths whose mothers have higher educational goals for their children.This research was supported by the National Institute of Mental Health, Grant No. MH36971. 相似文献
124.
Cyd C. Strauss Cynthia G. Last Michel Hersen Alan E. Kazdin 《Journal of abnormal child psychology》1988,16(1):57-68
The relationship between anxiety and depression was examined in a sample of 106 children and adolescents referred to an outpatient anxiety disorder clinic for children. Twenty-eight percent of patients with DSM-III diagnoses of anxiety disorders displayed a concurrent major depression. Children with anxiety disorders plus major depression were found (1) to be older, (2) to demonstrate more severe anxiety symptomatology, and (3) to be diagnosed with different rates of certain anxiety-disorder subtypes, when compared to anxious patients without major depression. Nondepressed anxious children and adolescents did not differ from a psychopathological control group in severity of either anxiety or depression symptoms. 相似文献
125.
Cyd C. Strauss Cynthia A. Lease Cynthia G. Last Greta Francis 《Journal of abnormal child psychology》1988,16(4):433-443
Differences between a clinical sample of younger (ages 5 to 11) and older (ages 12 to 19) children meeting DSM-III criteria for overanxious disorder (OAD) were examined. Younger and older children were compared in terms of (1) the rates of OAD diagnoses occurring in the two age groups, (2) sociodemographic characteristics, (3) symptom expression, (4) association with other forms of maladjustment, and (5) self-reported anxiety and depression. The prevalence of OAD diagnoses and sociodemographic characteristics did not differ. Although younger and older OAD children showed similar rates of most specific DSM-III OAD symptoms, older children presented with a higher total number of overanxious symptoms than younger children. Older children more frequently exhibited a concurrent major depression or simple phobia, whereas younger OAD children more commonly had coexisting separation anxiety or attention deficit disorders. Older OAD children reported significantly higher levels of anxiety and depression on self-report measures. Findings indicated that the expression of OAD varies by developmental level. 相似文献
126.
The possibility that rats can navigate in the Morris water maze by reducing the difference between the memorized platform scene and the current sensory input was tested in nine blind rats. A computerized videosystem monitored the rats' movements in the pool and converted the rat-target distance into tones the frequency of which increased in 64 equal steps from 120 Hz at 128 cm to 7680 Hz at 0 cm. During 15 days of training to find a fixed platform position from different starting points (12 trials per day) average escape latencies decreased from 39.0 to 25.4 s. The performance significantly deteriorated when the acoustic distance signalization was omitted and/or when the target position was changed form trial to trial. It is concluded that blind rats solved the task by simultaneously employing search strategy based on position responses, mapping using acoustic background beacons, and distance reduction navigation. It is argued that the various strategies are additive and that their relative significance depends of the conditions of the experiment. 相似文献
127.
Recent research has indicated strong relations between people's appraisals of their circumstances and their emotional states. The present study examined these relations across a range of unpleasant situations in which subjects experienced complex emotional blends. Subjects recalled unpleasant experiences from their pasts that were associated with particular appraisals and described their appraisals and emotions during these experiences. Situations defined by particular appraisals along the human agency or situational control dimensions were reliably associated with different levels of anger, sadness, and guilt, as predicted. However, predicted differences in emotion were not observed for situations selected for appraisals along the certainty or attention dimensions. Most subjects reported experiencing blends of two or more emotions, and correlation/regression analyses indicated that even in the context of these blends, patterns of appraisal similar to those observed previously (Smith & Ellsworth, 1985, 1987) characterized the experience of the individual emotions. The regressions further indicated that appraisals along some dimensions were more important to the experience of particular emotions than were appraisals along other dimensions. Thesecentral appraisals are compared with the adaptive functions their associated emotions are believed to serve, and the implications of these findings are discussed.This research was supported in part by a Stanford University graduate fellowship and in part by a National Institute of Mental Health training grant to Craig Smith. Part of the writing was done while Phoebe Ellsworth was a fellow at the Center for Advanced Study in the Behavioral Sciences, supported by the John D. and Catherine T. MacArthur Foundation and by the James McKeen Cattell Fund. 相似文献
128.
A 47-year-old right-handed man underwent craniotomy for clipping of an aneurism at the trifurcation of the left middle cerebral artery. Subsequently, he suffered a left hemisphere CVA after which his speech and language resembled that of Broca's aphasia with accompanying apraxia of speech. Medical, behavioral, and acoustical data amassed over a period of several months indicated numerous contraindications to traditional diagnoses of Broca's aphasia, apraxia of speech, and dysarthria. Ultimately, it was determined that the patient had a selective impairement of phonation or laryngeal apraxia. This was illustrated dramatically when he was taught to use an electrolarynx which allowed him to bypass his disrupted phonatory system. Speaking with the electrolarynx, the patient communicated normally. Any semblance of Broca's aphasia disappeared. Supralaryngeal articulation was normal; apraxia of speech behaviors were absent. This case report indicates that dissociation of oral and laryngeal gestures due to brain injury is possible. Mechanisms underlying such a dissociation for this case are reviewed. The possibility of discrete center lesions in the frontal motor association area causing different types of apraxia of speech is discussed. 相似文献
129.
A pediatric auditory version of the Stroop procedure was developed and administered to 48 normal children from 3 to 6 years of age. Our purpose was to define the developmental course characterizing interaction between auditory and semantic speech dimensions in young children. The procedure was a reaction time (RT) task that required children to respond as quickly and as accurately as possible to words spoken by a male or a female voice. Children were instructed to ignore what was said and to push the "Mommy" button if Mommy was talking or the "Daddy" button if Daddy was talking. Performance was obtained for words with neutral, congruent, and conflicting semantic content. Preschool children manifested processing dependencies that were similar to those observed in adults on the visual Stroop procedure. Conflict between semantic and auditory dimensions significantly increased RT and congruence between the two dimensions significantly decreased RT relative to the neutral condition. The pattern of results indicated that the meaning of words was processed automatically in the normal children. The magnitude of the Stroop effect reflected developmental change with increasing age. 相似文献
130.