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   6932篇
  免费   158篇
  国内免费   168篇
教育   5522篇
科学研究   987篇
各国文化   8篇
体育   183篇
综合类   336篇
文化理论   4篇
信息传播   218篇
  2024年   1篇
  2023年   25篇
  2022年   59篇
  2021年   140篇
  2020年   130篇
  2019年   166篇
  2018年   111篇
  2017年   112篇
  2016年   132篇
  2015年   144篇
  2014年   406篇
  2013年   520篇
  2012年   503篇
  2011年   530篇
  2010年   388篇
  2009年   374篇
  2008年   365篇
  2007年   499篇
  2006年   472篇
  2005年   376篇
  2004年   310篇
  2003年   323篇
  2002年   248篇
  2001年   236篇
  2000年   154篇
  1999年   119篇
  1998年   68篇
  1997年   86篇
  1996年   64篇
  1995年   44篇
  1994年   48篇
  1993年   23篇
  1992年   29篇
  1991年   14篇
  1990年   14篇
  1989年   11篇
  1988年   10篇
  1987年   1篇
  1957年   3篇
排序方式: 共有7258条查询结果,搜索用时 15 毫秒
1.
张坊岩溶地貌是中国北方岩溶类型的典型代表。分析张坊地区的地层展布与构造变形,探讨地层-构造演化与岩溶发育的关系。研究区主要出露近水平的中上元古界碳酸盐岩夹细碎屑岩和硅质岩,主要经历印支期(或更早期)伸展状态下的固态流变变形、燕山期的逆冲-褶皱变形和房山岩体期后的伸展变形等多期次构造演化,造就了研究区复杂的褶皱、断裂、构造裂隙和岩溶地貌特征。大型溶洞的发育主要与中上元古界的岩性-地层展布、中生代的逆冲断裂和新生代的伸展断裂等地质作用有关。在多阶段沉积-变形等地质作用控制下,发育了中元古代、古生代、中生代和新生代4期古岩溶,形成构造抬升侵蚀溶蚀、构造反转溶蚀冲蚀和多次抬升溶蚀侵蚀等3种主要溶洞发育类型。  相似文献   
2.
Self‐reported measures are an easy, time‐efficient, and low‐cost way to collect research data compared to other assessment methods. They are, however, characterized by several limitations regarding the quality and the clarity of the data they produce, especially when they are implemented in education. The main purpose of the current study was to use a method called discrete choice modeling (DCM) in education, in order to develop a self‐reported instrument that will reduce the bias for socially desirable responses and to assess teachers’ practices in physical activity. DCM method has the ability to overcome the respondents’ tendency to answer in a socially desirable way. A nationally representative sample of 531 Greek early educators participated in this study and were administered a self‐assessment questionnaire based on DCM. Results showed that the DCM based newly developed instrument manages to assess effectively educators’ practices and provided evidence of the applicability of the method in education. Further implications and future recommendations regarding the effective application of DCM in education are discussed.  相似文献   
3.
This case study explores how a group of Grade 9 students engaged in sociopolitical discourses and actions in a science class in a mostly indigenous student school in Nepal. The study used sociopolitical consciousness (SPC) as a framework to document and understand indigenous students’ SPC-oriented science interactions and subsequent social change actions. We used ethnographic methods of data collection over 6 months. The study focused on the actions of 4 girls and 2 boys belonging to the indigenous Tharu group. Data were analyzed using iterative qualitative methods. The study findings show that students are capable of engaging in critical thinking, critical reflecting, and taking actions for social change. Additionally, students are competent to link their experiences with social, structural, and political discrimination to the relevant science content they learn. The study presents four thematic findings related to SPC and science teaching and learning: Fostering social justice awareness in science class, fostering structural understanding of inequities in sickle cell disease, fostering sociopolitical actions for sickle cell disease, and the teacher's activist pedagogy for SPC in science learning. Implications of the study are that culturally relevant pedagogy helps indigenous students to become sociopolitically more aware of the links between science and social change. Adding aspects of critical pedagogies in science teaching could encourage students to become more sociopolitically reflective about science learning.  相似文献   
4.
Political polarization remains perhaps the “greatest barrier” to effective COVID-19 pandemic mitigation measures in the United States. Social media has been implicated in fueling this polarization. In this paper, we uncover the network of COVID-19 related news sources shared to 30 politically biased and 2 neutral subcommunities on Reddit. We find, using exponential random graph modeling, that news sources associated with highly toxic – “rude, disrespectful” – content are more likely to be shared across political subreddits. We also find homophily according to toxicity levels in the network of online news sources. Our findings suggest that news sources associated with high toxicity are rewarded with prominent positions in the resultant network. The toxicity in COVID-19 discussions may fuel political polarization by denigrating ideological opponents and politicizing responses to the COVID-19 pandemic, all to the detriment of mitigation measures. Public health practitioners should monitor toxicity in public online discussions to familiarize themselves with emerging political arguments that threaten adherence to public health crises management. We also recommend, based on our findings, that social media platforms algorithmically promote neutral and scientific news sources to reduce toxic discussion in subcommunities and encourage compliance with public health recommendations in the fight against COVID-19.  相似文献   
5.
通过文献资料调研、实地考察、专家访谈等方法,基于社会主要矛盾转化视角,对体育产业供给侧改革的投入要素、行动逻辑与实施路径进行研究。研究认为:1)中国特色社会主义步入新时代,社会主要矛盾的转化对体育产业供给侧改革提出了新要求,而体育产业供给侧改革可以有效破解体育产业中不平衡和不充分的发展问题;2)推进体育产业供给侧改革的核心工作是通过改革与创新,优化产业结构,提高劳动力、土地、资本、制度等要素的投入力度,提高全要素生产率;3)行动逻辑是构建“强政府-强市场”结合模式,不仅要用好政府“有形之手”,也要放开市场“无形之手”,发挥市场在体育资源配置中的决定性作用。具体实践中,通过深化体制机制改革、促进产业跨界融合、实施产业创新驱动、补齐产业发展短板等途径推进体育产业供给侧改革。  相似文献   
6.
本研究采用单一被试研究中的跨行为多探测设计,以成人与同伴混合视频示范作为干预策略,嵌入动机操作的原理,对一名孤独症儿童实施以玩偶为中介的虚构客体游戏行为的干预。研究结果显示:孤独症儿童在干预期的目标游戏中表现出的与视频脚本一致的假装游戏行为数量显著增加,并能够得到良好的维持;在未经教学的游戏情境中能够表现出恰当的虚构客体游戏行为,表明儿童习得的虚构客体游戏技能能够得到良好的泛化。  相似文献   
7.
唐诗知识图谱的构建及其智能知识服务设计   总被引:2,自引:0,他引:2  
[目的/意义]立足于当前大数据环境下的唐诗知识服务需求,以大规模唐诗数据为基础构建唐诗知识图谱并提供智能知识服务,推动人工智能环境下唐诗知识管理和知识服务方式的创新。[方法/过程]本文在对领域知识服务需求调研的基础上,设计领域知识服务驱动的唐诗本体模型,然后利用从Web上爬取的多源异构数据,采用知识抽取、知识融合、知识推理等技术自动构建唐诗知识图谱,统一表示和组织唐诗领域数据,实现对大规模唐诗数据的语义化处理。[结果/结论]本文设计基于唐诗知识图谱的智能知识服务平台KnowPoetry,提供唐诗领域的知识探索、时空轨迹、语义查询等智能化知识服务,推动人工智能环境下唐诗数字人文研究方法的创新转型。  相似文献   
8.
Despite increased acknowledgement of the significance of situational factors to engagement, engagement is traditionally seen as a student characteristic. In this study, we investigated to what extent variation in observational measures of behavioral student engagement during seatwork is due to students versus teachers, teacher-student dyads, or situational (i.e., variation in time) effects. Additionally, we studied whether adaptive support during teacher-student interactions contributes to student engagement following that interaction. A cross-classified multilevel analysis of 324 video- and audio-recorded secondary school teacher-student interactions showed that situational factors and error were the strongest source of variability in student engagement. Other than expected, teacher-related and dyad-related variability were limited. Although behavioral engagement after teacher-student interaction was significantly higher than pre-interaction student engagement, higher post-interaction levels were not related to the level of adaptive support provided during the teacher-student interaction. These findings imply that situational factors deserve more attention in engagement research, for example by investigating what situational factors contribute to engagement. For teachers, the time-variant, situation-dependent nature of engagement opens up valuable opportunities to actively design optimal learning situations.  相似文献   
9.
While there is a growing body of work that examines disciplinary identity development, unlike qualitative work in this area, quantitative research has not fully incorporated the importance of different contexts, nor has it uniquely focused on underrepresented groups (in this case, women in physics). This study examines how the constructs posited by prior work as important for physics identity, as well as an additional theorized construct, may interrelate and affect female students' physics identity differently depending on the context. Context in this study refers to two different experiential levels in college. The constructs examined include performance/competence, recognition, and interest, as well as sense of belonging. In particular, we used structural equation modeling to examine the effect that these constructs have on the physics identity of two groups of female physics undergraduates: first year students and senior year students. The results reveal that the relationship of the theorized constructs with physics identity vary between the two groups as well as compared to prior research with broad college student populations (not just physics majors). Unlike broad college student populations, for our sample of female physics undergraduates, interest did not have a direct effect on physics identity while sense of belonging was significant only for senior year students. These results exemplify the importance of examining context or different types of student experiences when studying disciplinary identity development rather than generalizing previous frameworks to all contexts.  相似文献   
10.
This study investigates the impact of teaching factors on students’ cognitive and metacognitive achievement in mathematics. Written tests and the “Metacognitive Skills and Knowledge Assessment” tool were administered to grade 4 and 5 students (n = 924) at the beginning and end of the school year 2013-2014. A student questionnaire was used for measuring teaching factors. Multilevel SEM analyses revealed a reciprocal relationship between students’ cognitive and metacognitive skills. All teaching factors of the dynamic model of educational effectiveness were found to be associated with mathematics achievement but only four factors (modeling, assessment, questioning, and dealing with misbehavior) were associated with two aspects of metacognition (i.e. prediction and evaluation). Implications of findings are drawn.  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