全文获取类型
收费全文 | 13678篇 |
免费 | 38篇 |
国内免费 | 70篇 |
专业分类
教育 | 8696篇 |
科学研究 | 968篇 |
各国文化 | 437篇 |
体育 | 2270篇 |
综合类 | 253篇 |
文化理论 | 96篇 |
信息传播 | 1066篇 |
出版年
2023年 | 118篇 |
2022年 | 143篇 |
2021年 | 83篇 |
2020年 | 74篇 |
2019年 | 71篇 |
2018年 | 58篇 |
2016年 | 89篇 |
2015年 | 229篇 |
2014年 | 567篇 |
2013年 | 648篇 |
2012年 | 637篇 |
2011年 | 1033篇 |
2010年 | 694篇 |
2009年 | 501篇 |
2008年 | 632篇 |
2007年 | 561篇 |
2006年 | 698篇 |
2005年 | 671篇 |
2004年 | 586篇 |
2003年 | 608篇 |
2002年 | 415篇 |
2001年 | 195篇 |
2000年 | 162篇 |
1999年 | 134篇 |
1998年 | 89篇 |
1997年 | 123篇 |
1996年 | 123篇 |
1995年 | 131篇 |
1994年 | 141篇 |
1993年 | 140篇 |
1992年 | 166篇 |
1991年 | 157篇 |
1990年 | 181篇 |
1989年 | 166篇 |
1988年 | 230篇 |
1987年 | 303篇 |
1986年 | 285篇 |
1985年 | 346篇 |
1984年 | 260篇 |
1983年 | 244篇 |
1982年 | 211篇 |
1981年 | 181篇 |
1980年 | 103篇 |
1979年 | 42篇 |
1958年 | 38篇 |
1957年 | 42篇 |
1956年 | 58篇 |
1955年 | 59篇 |
1954年 | 63篇 |
1953年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
Webb SJ Jones EJ Merkle K Venema K Greenson J Murias M Dawson G 《Child development》2011,82(6):1868-1886
Individuals with autism spectrum disorder (ASD) show differences in face processing abilities from early in development. To examine whether these differences reflect an atypical versus delayed developmental trajectory, neural responses to familiar and unfamiliar faces in twenty-four 18- to 47-month-old children with ASD were compared with responses of thirty-two 12- to 30-month-old typically developing children. Results of 2 experiments revealed that neural responses to faces in children with ASD resembled those observed in younger typically developing children, suggesting delayed development. Electrophysiological responses to faces were also related to parent report of adaptive social behaviors for both children with ASD and typical development. Slower development of the face processing system in ASD may be related to reduced self-directed "expected" experience with faces in early development. 相似文献
962.
Based on theoretically driven models, the Chicago School Readiness Project (CSRP) targeted low-income children's school readiness through the mediating mechanism of self-regulation. The CSRP is a multicomponent, cluster-randomized efficacy trial implemented in 35 Head Start-funded classrooms (N = 602 children). The analyses confirm that the CSRP improved low-income children's self-regulation skills (as indexed by attention/impulse control and executive function) from fall to spring of the Head Start year. Analyses also suggest significant benefits of CSRP for children's preacademic skills, as measured by vocabulary, letter-naming, and math skills. Partial support was found for improvement in children's self-regulation as a hypothesized mediator for children's gains in academic readiness. Implications for programs and policies that support young children's behavioral health and academic success are discussed. 相似文献
963.
Developmentalists are often interested in understanding change processes, and growth models are the most common analytic tool for examining such processes. Nonlinear growth curves are especially valuable to developmentalists because the defining characteristics of the growth process such as initial levels, rates of change during growth spurts, and asymptotic levels can be estimated. A variety of growth models are described beginning with the linear growth model and moving to nonlinear models of varying complexity. A detailed discussion of nonlinear models is provided, highlighting the added insights into complex developmental processes associated with their use. A collection of growth models are fit to repeated measures of height from participants of the Berkeley Growth and Guidance Studies from early childhood through adulthood. 相似文献
964.
Aubuchon-Endsley NL Grant SL Berhanu G Thomas DG Schrader SE Eldridge D Kennedy T Hambidge M 《Child development》2011,82(4):1238-1251
Male and female infants from rural Ethiopia were tested to investigate relations among hemoglobin (Hb), anthropometry, and attention. A longitudinal design was used to examine differences in attention performance from 6 (M = 24.9 weeks, n = 89) to 9 months of age (M = 40.6 weeks, n = 85), differences hypothesized to be related to changes in iron status and growth delays. Stunting (length‐for‐age z scores < ?2.0) and attention performance, t(30) = ?2.42, p = .022, worsened over time. Growth and Hb predicted attention at 9 months, R2 = .15, p < .05, but not at 6. The study contributes to the knowledge base concerning the relations among Hb, early growth, and attention. 相似文献
965.
The authors used a large sample of children (N ≈ 7,400) participating in the Early Childhood Longitudinal Study--Kindergarten Cohort (ECLS-K) to estimate kindergarten children's academic achievement growth trajectories in reading and mathematics. The authors were particularly interested in whether the growth trajectories of children with learning disabilities (LD) or speech language impairments (SLI)--as well as those of other groups of children--were consistent with a cumulative or compensatory developmental cycle. Both LD and SLI children displayed significantly lower levels of kindergarten reading achievement than nondisabled children. However, and over the subsequent 5 years of elementary school, only children with SLI lagged increasingly behind nondisabled peers in their reading skills growth. The authors observed a different pattern for mathematics achievement. Children with LD, but not SLI, lagged increasingly behind nondisabled children in their mathematics skills growth. The authors also observed some consistency in "poor-get-poorer" effects across reading and mathematic achievement for additional population subgroups. Those kindergarten children who were from lower socioeconomic status families, who were African American, and who more frequently displayed learning-related behavior problems initially had lower levels of reading and mathematics achievement and also lagged increasingly behind in their acquisition of these skills over time. Some groups of children, including those with SLI, experience a cumulative rather than a compensatory cycle of achievement growth. 相似文献
966.
967.
Bennett S Ward M Moreau K Fortin G King J Mackay M Plint A 《Child abuse & neglect》2011,35(11):930-936
Objective
We sought to determine the incidence, clinical features, and demographic profile of head injury secondary to suspected child maltreatment (abuse or neglect) in Canada to help inform the development and evaluation of prevention programs for abusive head injuries.Methods
From March 1, 2005 to February 28, 2008, an average of 2,545 paediatricians and paediatric subspecialists were surveyed monthly through the established network of the Canadian Paediatric Surveillance Program. We calculated incidence rates using the number of confirmed cases over the product of the duration of the study (3 years) and population estimates by age group.Results
There were 220 confirmed cases of head injury from suspected child maltreatment. The annual incidence rate was 14.1 per 100,000 for children less than 1 year of age and 1.4 per 100,000 for those less than 15 years. Seventy three percent (141) of cases involved infants less than 12 months of age and 52% (100) of cases involved infants less than 6 months of age. Seventy-five percent (165) of cases presented to the emergency room. With regard to outcome, 12% (27) of cases resulted in death and 45% (75) of survivors had neurological sequelae at discharge. Thirty percent (67) of all cases, as well as 30% (8) of deaths were previously known to child welfare authorities.Conclusion
This study provides an estimate of the rate of head injury secondary to suspected child maltreatment in Canada. The young age and poor medical outcomes of those involved highlights the need for prevention efforts that are implemented early in life. Given that a significant percentage of injured infants and children were already known to child welfare authorities, the study also highlights the need to establish and evaluate additional preventive efforts for parents and caregivers already in the child welfare system. 相似文献968.
Cuijpers P Smit F Unger F Stikkelbroek Y Ten Have M de Graaf R 《Child abuse & neglect》2011,35(11):937-945
Objectives
There is much evidence showing that childhood adversities have considerable effects on the mental and physical health of adults. It could be assumed therefore, that the disease burden of childhood adversities is high. It has not yet been examined, however, whether this is true.Method
We used data of a large representative sample (N = 7,076) of the general population in the Netherlands. We calculated the disability weight (DW) for each respondent. The DW is a weight factor that reflects the severity of a disease or condition on a scale from 0 (perfect health) to 1 (equivalent to death). We used an algorithm based on the SF-6D to estimate DW. Because the DW indicates the proportion of a healthy life year that is reduced by the specific health state of the individual, it also possible to calculate the total number of years lost due to disability (YLD) in the population. We calculated the years lived with disability (YLD) for 9 different childhood adversities (in the areas of parental psychopathology; abuse and neglect; major life events), as well as for major categories of mental disorders and general medical disorders.Results
All 9 adversities resulted in a significantly increased DW, except death of a parent before the age of 16. Adversities in the category of abuse and neglect are associated with the highest DWs (0.057), followed by parental psychopathology (0.031) and life events during childhood (0.012). All adversities (46.4% of the population reports one or more adversity) are associated with 20.7 YLD/1,000, which is more than all mental disorders together (12.9 YLD/1,000). The category of abuse/neglect has the highest YLD/1,000 (15.8), which is also higher than all mental disorders together. Adjustment for the presence of mental and general medical disorders resulted in comparable outcomes.Conclusions
Childhood adversities are more important from a public health point of view than all common mental disorders together, and should be a priority for public health interventions. 相似文献969.
Gunnlaugsson G Kristjánsson AL Einarsdóttir J Sigfúsdóttir ID 《Child abuse & neglect》2011,35(5):372-381
Objectives
During intrafamilial conflicts children are often innocent bystanders, caught in the crossfire. In such situations, they are at increased risk to become directly involved in abusive verbal behavior of the perpetrator, and exposed to being shouted or yelled at, threatened, rejected and even physically abused. The present study has two main objectives: (1) ascertain a national base rate of intrafamilial conflicts and physical violence at home among Icelandic adolescents; and (2) to investigate the association of witnessing and/or having been a part of intrafamilial conflict or physical violence at home with variables that relate to mental health and well-being.Methods
The participants were 3,515 students, 14- and 15-year-old, in the national compulsory school system in Iceland. As a part of the 2003 ESPAD survey, each pupil was asked about experiences of severe verbal arguments and physical violence at home as well as their background, behaviors, and mental health assessed with the use of tested measurement scales such as the Symptom Distress Checklist 90 (SCL-90) and the Rosenberg Self-Esteem Scale.Results
About 22% of the participants stated that they had witnessed a severe verbal argument between parents and 34% stated that they had been involved in a severe verbal argument with parents. This rate was slightly higher for girls compared to boys. All together 7% of adolescents had witnessed physical violence at home where an adult was involved and 6% of the participants stated that they had experiences of being involved in physical violence at home where an adult was involved. Witnessing or being involved in severe verbal arguments at home and/or witnessing or being involved in physical violence with an adult was significantly associated with greater levels of depression, anger, and anxiety, and negatively related with self-esteem (p < 0.01).Conclusions
Many adolescents in Iceland witness severe parental verbal arguments or physical violence between adults in their homes and some are directly involved in such acts. It affects their long-term emotional and behavioral development and well-being.Practice implications
Preventive measures have to be implemented at an early age and should include, but not be limited to, information on disciplining and upbringing of children and the negative impact of intrafamilial conflicts on the long-term health of their children. Due attention should be given to the health and well-being of children where such violence is known to occur. 相似文献970.
在发言开始前,我想对受邀参加本次校长会议表示感谢,并代表开普敦大学以及南非向清华大学表达诚挚的祝贺和良好的祝愿。如同中国大学一样,我国的大学也正逐步融入世界大学群体。由于数十年的种族隔离制度作祟,来自学术界的杯葛接踵而至,南非的大学与国外同行间的合作或交换关系发展得异常困难与复杂。即使在 相似文献