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   6960篇
  免费   150篇
  国内免费   57篇
  7167篇
  2018年   23篇
  2014年   17篇
  2012年   627篇
  2011年   729篇
  2010年   189篇
  2009年   86篇
  2008年   560篇
  2007年   624篇
  2006年   516篇
  2005年   460篇
  2004年   426篇
  2003年   459篇
  2002年   365篇
  2001年   247篇
  2000年   307篇
  1999年   153篇
  1998年   51篇
  1997年   38篇
  1996年   36篇
  1995年   36篇
  1994年   38篇
  1993年   27篇
  1992年   40篇
  1991年   47篇
  1990年   41篇
  1989年   45篇
  1988年   46篇
  1987年   41篇
  1986年   31篇
  1985年   39篇
  1984年   27篇
  1983年   45篇
  1982年   35篇
  1981年   32篇
  1980年   15篇
  1978年   25篇
  1976年   18篇
  1965年   28篇
  1963年   20篇
  1959年   20篇
  1958年   62篇
  1957年   54篇
  1956年   48篇
  1955年   37篇
  1954年   34篇
  1953年   28篇
  1952年   27篇
  1951年   27篇
  1950年   24篇
  1949年   14篇
排序方式: 共有7167条查询结果,搜索用时 15 毫秒
181.
Social information processing (SIP) patterns were conceptualized in orthogonal domains of process and context and measured through responses to hypothetical vignettes in a stratified sample of 387 children (50% boys; 49% minority) from 4 geographical sites followed from kindergarten through 3rd grade. Multidimensional, latent-construct, confirmatory factor analyses supported the within-construct internal consistency, cross-construct discrimination, and multidimensionality of SIP patterns. Contrasts among nested structural equation models indicated that SIP constructs significantly predicted children's aggressive behavior problems as measured by later teacher reports. The findings support the multidimensional construct validity of children's social cognitive patterns and the relevance of SIP patterns in children's aggressive behavior problems.  相似文献   
182.
The objective of this document is to provide health care professionals with recommendations for genetic counseling and testing of individuals with a suspected or confirmed diagnosis of Fabry disease, with a family history of Fabry disease, and those identified as female carriers of Fabry disease. These recommendations are the opinions of a multicenter working group of genetic counselors, medical geneticists, and other health professionals with expertise in Fabry disease counseling, as well as an individual with Fabry disease who is a founder of a Fabry disease patient advocacy group in the United States. The recommendations are U.S. Preventive Task Force Class III, and they are based on clinical experience, a review of pertinent English-language articles, and reports of expert committees. This document reviews the genetics of Fabry disease, the indications for genetic testing and interpretation of results, psychosocial considerations, and references for professional and patient resources. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. The professional judgment of a healthcare provider, familiar with the facts and circumstances of a specific case, will always supersede these recommendations.  相似文献   
183.
The positive effect of postlearning sleep on memory consolidation as well as the relationship between sleep-related memory processes and the hippocampal formation are increasingly clarified topics in neurobiology. However, the possibility of a stable relationship between waking mnemonic performance and sleep-dependent hippocampal electric activity is unexplored. Here we report a correlative analysis between sleep-dependent parahippocampal-hippocampal (pHip-Hip) electric activity recorded by foramen ovale (FO) electrodes and different types of memory performances in epileptic patients. Psychological testing was performed days or weeks before electrophysiological recordings. The relative spectral power of the slow activity (below 1.25 Hz) during deep non-REM (NREM) sleep at the right pHip-Hip region correlated positively with the visual memory performance according to Rey-Osterrieth Complex Figure Test (ROCFT). Along the posterior-anterior direction of the hippocampal formation a linear increasing of correlations was observed. The relative power of the activity below 1.25 Hz at the left pHip-Hip during phasic REM sleep correlated positively with verbal learning performance and mnemonic retention values according to ROCFT. It is concluded that the pHip-Hip structures' capacity of producing high amplitude and synchronized slow (< 1 Hz) oscillation during deep NREM sleep is related to the functional power of these structures. We hypothesize that the asymmetric (side-specific) propagation of ponto-geniculo-occipital (PGO) activity to the pHip-Hip region is related to the memory correlates of phasic REM sleep.  相似文献   
184.
The Brown ADD Scale for Adolescents is widely used in clinical settings, yet, no published studies have investigated divergent and concurrent validity and specificity and sensitivity to inattentive ADHD symptomatology. Ninety-eight participants (13 to 16 years) were classified as ADHD/I and/or reading disabled (RD) using Kiddie Schedule for Affective Disorder and Schizophrenia (K-SADS), Conners' Rating Scales (CRS-R), and Ontario Child Health Study Scales (OCHSS), WRAT3, and WRMT-R. The results were: 29 ADHD/I; 12 RD, 16 ADHD/I with RD; and, 41 controls. The RD group was included to evaluate specificity. The Brown was administered but not used in classification. The ADHD groups scored higher on the Brown subscales compared with the other two groups. The recommended cutoffs resulted in high rates of false negatives but few false positives; this suggests good specificity but poor sensitivity. There were moderate correlations among the Brown, CRS-R, and OCHSS. The Brown can be useful in screening out ADHD; however, its low sensitivity precludes its usefulness in diagnosing ADHD.  相似文献   
185.
A model integrating Japanese ethnicity, cultural identity, and anxiety was developed and assessed in Japanese American and part-Japanese American high school seniors (N = 141). Using measures from the Hawaiian High Schools Health Survey, the model incorporated the State-Trait Anxiety Inventory, the Major Life Events Scale, and the Japanese Culture Scale (JCS). Japanese American adolescents scored higher on the JCS and reported fewer anxiety symptoms than part-Japanese American adolescents. Predictors for anxiety were being Japanese American versus part-Japanese American, income, and culturally intensified events. A significant interaction of behavior by self-identification was obtained. The model had good overall fit, suggesting that cultural identity formation may contribute to anxiety experienced particularly by adolescents of mixed heritage.  相似文献   
186.
187.
The current legal framework within the Lithuanian health system is described including a review of the physician’s autonomy, rights and duties, and patients’ rights including the right to reimbursement. The role of ethical codes and the law are discussed. An earlier version of this paper was presented at an International Conference on “Conflict of Interest and its Significance in Science and Medicine” held in Warsaw, Poland on 5–6 April, 2002.  相似文献   
188.
189.
This paper investigates which of the various legal notions proposed for human DNA is the most appropriate from an ontological viewpoint - unique legal status, private property, common property, person, or information. The focus is on the difficulties that private property, common property and person present. By using Harré's notion of "file-self" we argue that, ontologically, the most appropriate legal notion to be applied is information. This has consequences for storage, control and use of genetic information as well as identifiable human body material.  相似文献   
190.
This study examined the modulatory function of Duchenne and non-Duchenne smiles on subjective and autonomic components of emotion. Participants were asked to hold a pencil in their mouth to either facilitate or inhibit smiles and were not instructed to contract specific muscles. Five conditions--namely lips pressing, low-level non-Duchenne smiling, high-level non-Duchenne smiling, Duchenne smiling, and control--were produced while participants watched videoclips that were evocative of positive or negative affect. Participants who displayed Duchenne smiles reported more positive experience when pleasant scenes and humorous cartoons were presented. Furthermore, they tended to exhibit different patterns of autonomic arousal when viewing positive scenes. These results support thefacial feedback hypothesis and suggest that facial feedback has more powerful effects when facial configurations represent valid analogs of basic emotional expressions.  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