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   2222篇
  免费   74篇
  2022年   14篇
  2021年   15篇
  2020年   34篇
  2019年   34篇
  2018年   66篇
  2017年   52篇
  2016年   57篇
  2015年   51篇
  2014年   71篇
  2013年   266篇
  2012年   85篇
  2011年   76篇
  2010年   66篇
  2009年   66篇
  2008年   76篇
  2007年   90篇
  2006年   104篇
  2005年   89篇
  2004年   61篇
  2003年   74篇
  2002年   62篇
  2001年   42篇
  2000年   32篇
  1999年   44篇
  1998年   42篇
  1997年   31篇
  1996年   31篇
  1995年   31篇
  1994年   34篇
  1993年   30篇
  1992年   28篇
  1991年   31篇
  1990年   23篇
  1989年   25篇
  1987年   16篇
  1986年   18篇
  1985年   20篇
  1984年   31篇
  1983年   20篇
  1982年   27篇
  1981年   23篇
  1980年   17篇
  1979年   26篇
  1978年   19篇
  1977年   22篇
  1976年   15篇
  1975年   10篇
  1974年   15篇
  1973年   14篇
  1968年   10篇
排序方式: 共有2296条查询结果,搜索用时 31 毫秒
131.
Nine patients with semantic dementia (the temporal lobe variant of frontotemporal dementia) were asked to define concrete concepts either from presentation of a picture of the object or from its spoken name. As expected, the patients with the most severe semantic impairment produced the least detailed definitions, and the quality of the definitions overall was significantly related to concept familiarity. Further analyses of the definitions were designed to assess two key theoretical aspects of semantic organization. (i) Do objects and their corresponding names activate conceptual information in two neuroanatomically separable (modality-specific) semantic systems? If so, then-apart from any expected commonality in performance attributable to factors such as concept familiarity-one would not predict striking item-specific similarities in a patient's picture- and word-elicited definitions. (ii) Do sensory/perceptual features and more associative/functional attributes of conceptual knowledge form two neuroanatomically separable subsystems? If so, then one would predict significant dissociations in the prominence of these two types of information in the patients' definitions. The results lead us to favor a model of the semantic system that is divided by attribute type but not by modality.  相似文献   
132.
133.
Performance in the Wason card selection task is often improved given thematic content. Such content effects have been considered evidence against human rationality. We propose that the role of content lies in specifying premises underlying "if P, then Q" rules. Unlike thematic rules, abstract conditional rules do not explicitly provide material interpretation (P is a sufficient but not necessarily a necessary condition for Q), resulting in nonnormative responses. When necessity–sufficiency relations were explicated, normative responses were elicited and effects of other logically irrelevant components disappeared. The results suggest that content effects are compatible with human rationality.  相似文献   
134.
Seventeen-month-old infants were presented with pairs of images, in silence or with the non-directive auditory stimulus ‘look!’. The images had been chosen so that one image depicted an item whose name was known to the infant, and the other image depicted an image whose name was not known to the infant. Infants looked longer at images for which they had names than at images for which they did not have names, despite the absence of any referential input. The experiment controlled for the familiarity of the objects depicted: in each trial, image pairs presented to infants had previously been judged by caregivers to be of roughly equal familiarity. From a theoretical perspective, the results indicate that objects with names are of intrinsic interest to the infant. The possible causal direction for this linkage is discussed and it is concluded that the results are consistent with Whorfian linguistic determinism, although other construals are possible. From a methodological perspective, the results have implications for the use of preferential looking as an index of early word comprehension.  相似文献   
135.
136.
This longitudinal study was conducted among 102 women with non-metastasic breast cancer to identify the time evolution and prevalence of distress at specific times through diagnosis and treatment of disease: preliminary diagnosis, surgery, definitive diagnosis and chemotherapy. Additionally, the study aimed to examine the role of demographic, medical and psychosocial factors on distress. The results indicated that prevalence of distress was higher at initial diagnosis (25%) than the following time points (approximately 17%). The differences inter-individuals in the levels of distress were observed over the four assessments. No relation between distress and demographic and medical factors was found. However, psychosocial aspects were significant risk factors. Patterns of emotional suppression and specific coping responses like helplessness/hopelessness, anxious preoccupation, cognitive avoidance and fatalism were positively related to distress, whereas fighting spirit and perceived social support showed a protective role. Moreover, helplessness/hopelessness and anxious preoccupation jointly predicted 75% of cases and 98% non-cases of distress. Finally, a mediational model between emotional suppression and distress through helplessness/hopelessness was tested. Results support the necessity of routine distress screening all through the illness. Implications of data for psychosocial interventions with breast cancer patients are highlighted.  相似文献   
137.
Aggression between partners represents a potential guiding force in family dynamics. However, research examining the influence of partner aggression (physically and psychologically aggressive acts by both partners) on harsh parenting and young child adjustment has been limited by a frequent focus on low-risk samples and by the examination of partner aggression at a single time point. Especially in the context of multiple risk factors and around transitions such as childbirth, partner aggression might be better understood as a dynamic process. In the present study, longitudinal trajectories of partner aggression from birth to age 3 years in a large, high-risk, and ethnically diverse sample (N = 461) were examined. Specific risk factors were tested as predictors of aggression over time, and the longitudinal effects of partner aggression on maternal harsh parenting and child maladjustment were examined. Partner aggression decreased over time, with higher maternal depression and lower maternal age predicting greater decreases in partner aggression. While taking into account contextual and psychosocial risk factors, higher partner aggression measured at birth and a smaller decrease over time independently predicted higher levels of maternal harsh parenting at age 3 years. Initial level of partner aggression and change over time predicted child maladjustment indirectly (via maternal harsh parenting). The implications of understanding change in partner aggression over time as a path to harsh parenting and young children's maladjustment in the context of multiple risk factors are discussed.  相似文献   
138.
Telehealth involves the use of information and communications technology to deliver health services to patients over distance. Canada is well suited to benefit from telehealth since many individuals live in remote, rural and isolated locations. Manitoba is the easternmost prairie province and MBTelehealth is an active Canadian program that currently has 105 sites in 73 communities. Although studies of patient satisfaction comparing telehealth to on-site clinical visits have been conducted, a comparative study of the types of genetics patients seen via these two modalities has not been performed previously. In this study we: (1) examined the uptake of telehealth in Genetics in Manitoba; (2) contrasted telehealth usage in Genetics with other clinical programs; and (3) performed a comparative study of the types of Genetics referrals seen in 2008 on-site versus via telehealth. Results indicate the uptake of telehealth is increasing and has made genetics outreach clinics unnecessary. The Program of Genetics and Metabolism is consistently one of the top ten utilizers of telehealth within the province. With respect to discipline, chi square analysis revealed the trends were not significantly different for on-site and telehealth encounters, with prenatal referrals being the most common and Hereditary Breast and Ovarian Cancer referrals being the least common. Referrals within each discipline varied depending on the need for fetal assessment and physical examination. Telehealth was utilized regularly for test results sessions across all disciplines.  相似文献   
139.
We describe the association between postpartum depression and the quantity and content of infant media use. Households with depressed mothers viewed twice as much television as households with non-depressed mothers did, and depressed mothers appeared to derive comparatively greater pleasure from television viewing. Maternal depression was associated with an increased exposure to child-directed content by 6–9-month-old infants, although it was not associated with an increased exposure to adult-directed programming. Depressed mothers also reported being less likely to sit and talk with their children during television use or to consult outside sources of information about media. This increase in television exposure without corresponding parental involvement could negatively affect developmental outcomes.  相似文献   
140.
A fundamental step in learning words is the development of an association between a sound pattern and an element in the environment. Here we explore the nature of this associative ability in 12‐month‐olds, examining whether it is constrained to privilege particular word forms over others. Forty‐eight infants were presented with sets of novel English content‐like word–object pairings (e.g. fep) or novel English function‐like word–object (e.g. iv) pairings until they habituated. Results indicated that infants associated novel content‐like words, but not the novel function‐like words, with novel objects. These results demonstrate that the mechanism with which basic word–object associations are formed is remarkably sophisticated by the onset of productive language. That is, mere associative pairings are not sufficient to form mappings. Rather the system requires well‐formed noun‐like words to co‐occur with objects in order for the linkages to arise.  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