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71.
With the availability of the whole genome sequence of Escherichia coli or Corynebacterium glutamicum, strategies for directed DNA manipulation have developed rapidly. DNA manipulation plays an important role in understanding the function of genes and in constructing novel engineering bacteria according to requirement. DNA manipulation involves modifying the autologous genes and expressing the heterogenous genes. Two alternative approaches, using electroporation linear DNA or recombinant suicide plasmid, allow a wide variety of DNA manipulation. However, the over-expression of the desired gene is generally executed via plasmid-mediation. The current review summarizes the common strategies used for genetically modifying E. coli and C. glutamicum genomes, and discusses the technical problem of multi-layered DNA manipulation. Strategies for gene over-expression via integrating into genome are proposed. This review is intended to be an accessible introduction to DNA manipulation within the bacterial genome for novices and a source of the latest experimental information for experienced investigators.  相似文献   
72.
Prolonged inspection of a Chinese character induces a feeling of uncertainty of the character, a phenomenon named as Orthographic Satiation. However, there has not been direct evidence showing that such satiation does occur at the orthographic level. To investigate whether Chinese satiation occurs at the orthographic level or at other levels, the present study applies a speeded repetition priming paradigm to Chinese, which has been successfully used to examine Semantic Satiation in English. When judging whether a category name matched an exemplar word, participants showed gradually slower responses as the character standing for the category name was repeated, indicating the occurrence of satiation. However, repetition of a character without accessing its meaning, or repeated access to its meaning without repeating the character itself, did not elicit satiation. The results suggest Orthographic Satiation occurs not at the orthographic level, but at a level associating orthography and meaning during Chinese character reading.  相似文献   
73.
The foundation of Shanxi University is a prime example of the collaborative efforts in higher education between the Chinese and British in late Qing China (1842–1912). Both sides made compromises, with the Chinese adapting their ideas of educational sovereignty, and the British agreeing to work under the supervision of the local government. Such a collaboration was made possible by the individual personalities of the two founders and their visions for China’s higher education. The dual structure of the university, with one department to teach Chinese learning and the other to teach Western learning, showed that, at a local and personal level, these officials and missionaries opted for direct cooperation, despite the myriad changes and upheavals following the Boxer Movement. In addition, by allowing foreign missionaries into critical roles in a government university, the principle of ti-yong dualism was gradually being adapted. The formation of Shanxi University not only demonstrates the dynamics of the Sino-Western educational relationship and the roles individuals played in it, but also stimulates reflection on China’s contemporary cross-border partnerships in higher education  相似文献   
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How does classroom interaction support students’ apprenticeship into the ways of speaking, writing, and diagramming that constitute the practice of mathematics? We address this problem through an interpretative analysis of a whole-group conversation about alternative ways of solving a problem involving percent discounts that occurred in a sixth grade classroom. This research study draws upon Dewey’s theory of inquiry, Vygotsky’s cultural–historical psychology, Freudenthal’s realistic mathematics education, and Halliday’s systemic functional linguistics (SFL). From Freudenthal, we borrow the notions of mathematizing and guided reinvention—the former notion offers a view of mathematics as an activity of structuring subject matter and the latter one provides insights into the processes whereby mathematizing is learned and taught in the classroom. We glean from Dewey his view of reflective thinking as inquiry and the role that conversations may serve therein. We rely upon Vygotsky’s notions of a verbal thinking plane and a social phase of learning in order to reconsider the function of whole-class interaction in apprenticing students into mathematizing. Finally, SFL provides us with tools for explaining the choices of grammar and vocabulary students and teachers make as they realize meanings in whole-group conversations. Treating the selected whole-class conversation as a text, we focus our analysis on how this text came to mean what it did. Our central questions are as follows: What meanings were realized in the whole-class conversation by teacher and students and how were these meanings realized? How did the teacher’s lexico-grammatical choices guide the students’ choices? In addressing these questions, we advance an interpretation of the conversation as paradigmatic of students and teacher thinking aloud together about percents.  相似文献   
77.
Inhibitory control, the ability to restrain a prepotent but ineffective response in a given context, is thought to be indicative of a species’ cognitive abilities. This ability ranges from “basic” motoric self-regulation to more complex abilities such as self-control. During the current study, we investigated the motoric self-regulatory abilities of 30 pet dogs using four well-established cognitive tasks – the A-not-B Bucket task, the Cylinder task, the Detour task, and the A-not-B Barrier task – administered in a consistent context. One main goal of the study was to determine whether the individual-level performance would correlate across tasks, supporting that these tasks measure similar components of motoric self-regulation. Dogs in our study were quite successful during tasks requiring them to detour around transparent barriers (i.e., the Cylinder and Detour tasks), but were less successful with tasks requiring the production of a new response (i.e., A-not-B Bucket and A-not-B Barrier tasks). However, individual dog performance did not correlate across tasks, suggesting these well-established tasks likely measure different inhibitory control abilities, or are strongly influenced by differential task demands. Our results also suggest other aspects such as perseveration or properties of the apparatus may need to be carefully examined in order to better understand canine motoric self-regulation or inhibitory control more generally.  相似文献   
78.
In the process of children’s talent development, fathers have been largely ignored compared to mothers who are mostly identified as the initial and primary influence for their children. Though modern fathers are becoming more engaged in childrearing and interacting more with their children and changes in family systems lead to new challenges and demands for defining parental roles today, fathers are still predominately portrayed as the principal breadwinners of families. Literature including both empirical and anecdotal data has documented positive and promising outcomes of paternal involvement for children’s talent development though fathers’ roles are not always differentiated from mothers’ roles and little research studied fathers and gifted children, exclusively. This paper includes a comprehensive review of fathers’ contributions to children’s talent development and discussion about issues and suggestions for research involving fathers and talent development.  相似文献   
79.
Many theories of giftedness either explicitly or implicitly acknowledge the role of genetic influences; yet, empirical work has not been able to establish the impact that genes have specifically on gifted behavior. In contrast, a great deal of research has been targeted at understanding the etiology of individual differences in general and specific cognitive abilities across the entire range of ability and to a lesser extent, high cognitive ability. This paper attempts to outline what we know and what we don't know about the etiology of giftedness as operationally defined as high g. We review studies selected to represent a variety of approaches that each address a different question about genetics and giftedness. These studies include quantitative genetic research which estimate heritability, shared and nonshared family environment – at the high and low ends of intelligence – as well as the heritability of group differences for general cognitive ability and specific cognitive abilities. We discuss the molecular genetic methods and mechanisms contributing to cognitive ability and suggest how epigenetic factors may operate. Quantitative and molecular genetic studies that include endophenotypes representing intelligence at a level closer to the genotype, are also included. This last group of studies represent a relatively new area of work that builds on and extends the extensive groundwork established by classic quantitative genetic studies of behavior.  相似文献   
80.
Mathematics teacher education aims to improve teachers’ use of mathematical knowledge to support teaching and learning, an aspect of pedagogical content knowledge (PCK). In this study, we interviewed teachers to understand how they used mathematics to make sense of student solutions to proportional reasoning problems. The larger purpose was to find accurate ways of categorizing teachers’ ability to do this vital aspect of teaching and thereby to inform assessment, teacher education, and professional development. We conjectured that teachers’ PCK for proportional reasoning could be reliably described in terms of attention to quantitative meanings in story problem contexts and in terms of understanding naïve forms of proportional reasoning. Instead, our findings reveal that individual teachers used a variety of means to make sense of (1) cognitively similar student solutions to different tasks and (2) mathematically related steps of a student solution within a single task. These findings illustrate the complexity of PCK for the topic of proportional reasoning and suggest the limits of what can be inferred about teacher knowledge from teachers’ evaluations of student solutions. We discuss implications for teacher education and assessment.  相似文献   
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