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   17017篇
  免费   183篇
  国内免费   9篇
教育   12255篇
科学研究   1612篇
各国文化   119篇
体育   1331篇
综合类   8篇
文化理论   126篇
信息传播   1758篇
  2021年   135篇
  2020年   191篇
  2019年   354篇
  2018年   506篇
  2017年   482篇
  2016年   445篇
  2015年   271篇
  2014年   360篇
  2013年   3142篇
  2012年   351篇
  2011年   428篇
  2010年   282篇
  2009年   263篇
  2008年   391篇
  2007年   282篇
  2006年   347篇
  2005年   250篇
  2004年   227篇
  2003年   207篇
  2002年   246篇
  2001年   353篇
  2000年   317篇
  1999年   299篇
  1998年   163篇
  1997年   175篇
  1996年   203篇
  1995年   203篇
  1994年   162篇
  1993年   188篇
  1992年   271篇
  1991年   242篇
  1990年   241篇
  1989年   280篇
  1988年   276篇
  1987年   233篇
  1986年   230篇
  1985年   249篇
  1984年   227篇
  1983年   260篇
  1982年   203篇
  1981年   178篇
  1980年   179篇
  1979年   255篇
  1978年   199篇
  1977年   189篇
  1976年   174篇
  1975年   138篇
  1974年   136篇
  1973年   140篇
  1971年   117篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Research Findings: This study explored the relations between Spanish–English dual language learner (DLL) children’s home language and literacy experiences and their expressive vocabulary and oral comprehension abilities in Spanish and in English. Data from Spanish–English mothers of 93 preschool-age Head Start children who resided in central Pennsylvania were analyzed. Children completed the Picture Vocabulary and Oral Comprehension subtests of the Batería III Woodcock–Muñoz and the Woodcock–Johnson III Tests of Achievement. Results revealed that the language spoken by mothers and children and the frequency of mother–child reading at home influenced children’s Spanish language abilities. In addition, the frequency with which children told a story was positively related to children’s performance on English oral language measures. Practice or Policy: The findings suggest that language and literacy experiences at home have a differential impact on DLLs’ language abilities in their 2 languages. Specific components of the home environment that benefit and support DLL children’s language abilities are discussed.  相似文献   
992.
This study explored the role of student (e.g., age, language background, gender), home (e.g., parent/caregiver education), and school (e.g., school type, size) socio-demographic factors in students’ school (e.g., in-school arts tuition, arts engagement), home (e.g., parent/caregiver–child arts interaction), and community (e.g., arts attendance, arts tuition) arts participation. The sample comprised 1172 elementary and secondary school students from 15 schools. Findings revealed that student and home socio-demographic factors were the most salient in predicting arts participation across school, home, and community contexts. Age, gender, and prior achievement were the key student socio-demographic factors, while parent/caregiver education and occupation were also associated with students’ arts participation. Implications for practice and intervention pertinent to young people’s arts participation are discussed.  相似文献   
993.
Immunization with a proper dose of an antigenic stimulus leads to cell proliferation and antibody response of circulating lymphocytes. We have previously observed that Secondary immunized spleenocytes resist ceramide-mediated apoptosisin vitro. Our present study is aimed at investigating thein vivo effect of immunization on apoptosis. Mice were subjected to either Primary or Secondary dose with Tetanus Toxoid. Unimmunized spleenocytes served as controls. Unimmunized, Primary and Secondary immunized mice were later exposed to chemotherapeutic drugs such as Etoposide/Methotrexate/Vincristine to induce apoptosis. Apoptosis was studied by using the Feulgen reaction on 5μ thin parafin sections of spleen. It was observed that Secondary immunized mice showed a lower percentage of apoptosis as compared to Primary or Unimmunized mice that was subjected to either of the chemotherapeutic drugs. It was thus concluded that Secondary immunization inhibits the process of chemotherapeutic drug induced apoptosis in vivo.  相似文献   
994.
Would the reader identify with a supervisor of K-6 science, a supervisor selecting NSF-sponsored materials, or a university science educator? The author finds differences in the perception of a supervisor's role.  相似文献   
995.
This study examined the effects of a newly developed on-site consultancy programme to improve global quality of the child care environment in non-parental child care centres for 0- to 4-year-old children as measured with the ITERS-R/ECERS-R. Using a randomised controlled trial with a pretest, posttest, and follow-up test, we compared 35 experimental group with 33 control group. The consultancy programme comprised three consultations in total. Analysis on the items that were specifically targeted during the consultancy showed a significant improvement on these targeted items between pretest and posttest and between posttest and follow-up. The effect of the consultancy programme on the total scores (including the non-targeted items) was not significant.  相似文献   
996.
In this paper, we report the discrete frequencies at which golf balls can vibrate, the mode patterns of these vibrations and how these modes can be excited. There are two broad classes of modes: those that radiate sound waves and those that do not. Both silent and acoustic modes are excited by tangential (i.e. spin-producing) impact forces; only acoustic modes are excited by radial impact forces. Exact analytical results for a homogeneous ball core are compared with finite element numerical results for both a core and a model two-piece ball. Correspondences are readily established for the important low-frequency modes, and the good agreement suggests the validity of these results for real golf balls. The results potentially provide the basis for a rapid, simple and non-destructive method of measuring the effective high-frequency elastic shear modulae of balls (and ball cores) as well as a method for 'tuning' the performance of balls for specific clubs. Some of these aspects are explored further in our companion paper in this issue.  相似文献   
997.
Within the context of classroom learning, strategic transfer can be viewed as a tool for academic problem solving. Strategic transfer is defined as the spontaneous access and retrieval (remembering) of previously learned formal procedures for the successful solution of a problem. The transfer-appropriate processing encoding model (Morris, Bransford, and Franks, 1977), and the transfer-appropriate procedures retrieval model (Roediger, Weldon, and Challis, 1989) are reviewed. An integration of the two models is proposed through the development of a training-for-transfer paradigm (Phye, 1990). By integrating encoding and retrieval processing in a single transfer paradigm the issue of accessing prior knowledge (Bransford, 1990) that is also referred to as the inert knowledge problem (Whitehead, 1929) can directly be addressed.  相似文献   
998.
In 671 mother–child (49% male) pairs from an epidemiological birth cohort, we investigated (a) prospective associations between DNA methylation (at birth) and trajectories (ages 7–13) of oppositional defiant disorder (ODD), and the ODD subdimensions of irritable and headstrong; (b) common biological pathways, indexed by DNA methylation, between ODD trajectories and attention deficit hyperactivity disorder (ADHD); (c) genetic influence on DNA methylation; and (d) prenatal risk exposure associations. Methylome‐wide significant associations were identified for the ODD and headstrong, but not for irritable. Overlap analysis indicated biological correlates between ODD, headstrong, and ADHD. DNA methylation in ODD and headstrong was (to a degree) genetically influenced. DNA methylation associated with prenatal risk exposures of maternal anxiety (headstrong) and cigarette smoking (ODD and headstrong).  相似文献   
999.
1000.
What is the relationship between the context and substantive meaning of a measure and the assessment of the reliability of the measure? Does the interpretation of a reliability coefficient depend on the nature of the measure? How does this approach to reliability relate to alternative assessments?  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