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71.
72.
Assessing the credibility of evidence in complex, socio‐scientific problems is of paramount importance. However, there is little discussion in the science education literature on this topic and on how students can be supported in developing such skills. In this article, we describe an instructional design framework, which we call the Credibility Assessment Framework, to scaffold high school students' collaborative construction of evidence‐based decisions and their assessment of the credibility of evidence. The framework was employed for the design of a web‐based reflective inquiry environment on a socio‐scientific issue, and was enacted with 11th grade students. The article describes the components of the Credibility Assessment Framework and provides the details and results of an empirical study illustrating this framework in practice. The results are presented in the form of a case study of how 11th grade students investigated and evaluated scientific data relating to the cultivation of genetically modified plants. Multiple kinds of data were collected, including pre‐ and post‐tests of students' conceptual understanding and their skills in assessing the credibility of evidence, and videotapes of students' collaborative inquiry sessions. The analysis of the pre‐ and post‐tests on students' conceptual understanding of Biotechnology and their skills in assessing the credibility of evidence revealed statistically significant learning gains. Students' work in task‐related artifacts and the analysis of two groups' videotaped discussions showed that students became sensitive to credibility criteria, questioned the sources of data and correctly identified sources of low, moderate, and high credibility. Implications for designers and educators regarding the application of this framework are discussed. © 2011 Wiley Periodicals, Inc. J Res Sci Teach 48: 711–744, 2011  相似文献   
73.
Teachers are encouraged to enhance professional competence through reflective practice and they are also asked to undertake research to generate evidence for their professional practices. This paper reports on an inquiry into a group of primary school English language teachers’ research engagement in the province of Guangdong on the Chinese mainland. The inquiry explored the effect of educational reforms on the participants’ research engagement through the use of an open‐ended questionnaire and group interviews. The inquiry revealed that research engagement had become an important part of the teachers’ professional lives. Emerging findings from the inquiry also problematised their research engagement as it was found to have been undermined by a competitive promotion mechanism, the teachers’ conceptualisations of research and challenges in the knowledge dissemination process. The paper ends with reflections on how to make teacher research “educational” for teachers and serve as an effective way for professional development.  相似文献   
74.
针对卫星扩频通信系统的时间同步需求,提出一种基于GNSS授时的卫星通信前向链路间接时间同步方法。通过由星地自发自收链路与锁相环构成的钟差间接修正环路,对发送端码时钟进行闭环修正。这将使前向链路信号起始扩频码相位在到达接收端的时刻与卫星导航授时模块输出的1 PPS保持精确稳定的同步。实现了不需要位同步的扩频信号定时接收。分析并得到间接时间同步误差表达式及其与环路带宽的变化关系,给出使同步误差最小的最优环路带宽值。星地链路试验结果表明时间同步误差随环路带宽的变化关系与理论分析一致,最佳环路带宽对应的钟差间接修正环路秒脉冲1σ同步误差约为20 ns,验证了本方法的有效性。在此同步误差条件下,接收端成功地进行扩频伪码的同步和电文解调,实现了卫星导航授时对通信的辅助。  相似文献   
75.
BMI和心肺适能对全代谢综合征男性最大脂代谢水平的影响   总被引:1,自引:0,他引:1  
目的:探究BMI和心肺适能对全代谢综合征男性最大脂代谢水平的影响.方法:采用CDS代谢综合征诊断标准募集24名全代谢综合征(tMS)男性.血清指标检测采用酶法和放免法.直接测定最大耗氧量和最大有氧功.间接测热法和非连续递增负荷法检测最大脂代谢水平.分别依据BMI、最大耗氧量的平均值将被试分为高,低BMI组,高、低心肺适能组.结果:tMS男性整体最大脂氧化率(MFOR)为151.58±20.64 mg/min,最大脂氧化强度(Fatmax)为28.48±5.98%VO2max,Fatmax相应RER为0.94±0.01;供能交叉点为33.42±6.96%VO2max,心肺适能水平为18.25±2.68 ml/kg/mim;高、低BMI组间心肺适能、MFOR、Fatmax和交叉点均无显著性差异;高、低心肺适能组间MFOR具有非常显著性差异(P<0.01),但BMI、Fatmax和交叉点强度均无显著性差异;tMS男性BMI与MFOR相关不具显著性,心肺适能与MFOR具显著性正相关(r=0.75,P<0.01).结论:全代谢综合征男性最大脂氧化强度处于低有氧强度范围,tMS男性最大脂氧化率受心肺适能水平影响,而BMI对其无显著影响.  相似文献   
76.
本报告首先梳理了西方档案理论与档案史,探讨了那些激发档案专业思想、战略及方法的概念,其次又着重阐述了档案鉴定这个由档案工作者从人类文献记录中挑选出很小比例作为档案长久保存的过程。19世纪至今的档案工作者对其工作、职能、活动及社会作用的认识经历了(或者说显示了)四个大的思想框架(或范式),探讨和了解这个背景可以让我们更好地认识和应对我们现在所处的这个数字时代的挑战。  相似文献   
77.
Nitric oxide (NO) a free radical having both cytoprotective as well as tumor promoting agent is formed from l-arginine by converting it to l-citrulline via nitric oxide synthase enzymes. The reaction product of nitric oxide with superoxide generates potent oxidizing agent, peroxynitrite which is the main mediator of tissue and cellular injury. Peroxynitrite is reactive towards many biomolecules which includes amino acids, nucleic acid bases; metal containing compounds, etc. NO metabolites may play a key role in mediating many of the genotoxic/carcinogenic effects as DNA damage, protein or lipid modification, etc. The basic reactions of nitric oxide can be divided as direct effect of the radical where it alone plays a role in either damaging or protecting the cell milieu and an indirect effect in which the byproducts of nitric oxide formed by convergence of two independent radical generating pathways play the role in biological reactions which mainly involve oxidative and nitrosative stress. Nitric oxide is also capable of directly interacting with mitochondria through inhibition of respiration or by permeability transition. Reaction of nitric oxide with metal ions include its direct interaction with the metals or with oxo complexes thereby reducing them to lower valent state. Excessive production of nitric oxide can be studied by inhibiting the synthetic pathway of nitric oxide using both selective or specific nitric oxide synthase inhibitor or non-selective nitric oxide synthase inhibitor with respect to isoforms of nitric oxide.  相似文献   
78.
综合运用知识管理与合作竞争理论,将间接互惠、情感利他等机制引入到了科研团队的动态分析中,建立了多Agent合作与竞争交互规则,在Swarm平台上进行了仿真.根据仿真结果,对科研团队的合作模式、信任关系、资源数量、平等程度、梯队建设、合作氛围及文化背景等进行了进一步分析,得到科研团队建设方面的一些启示.  相似文献   
79.
徐盈之  胡永舜 《软科学》2011,25(4):69-75
通过计算我国2007年制造业部门的碳排放量情况,对比了我国制造业部门各行业的直接碳排放及由最终需求引致的碳排放,并利用投入产出模型将由最终需求引致的碳排放量分解为直接效应、反馈效应、溢出效应、自给效应以及自溢效应。研究发现,在直接排放中,石油加工、炼焦及核燃料加工业这类化石能源消耗较大产业的碳排放量最大,而由最终需求引致的总排放中,通用、专用设备制造业和通信设备、计算机及其他电子设备制造业这类高技术产业的排放量最大;同时,分解研究发现,制造业部门碳排放的溢出效应最大,主要对象是能源产业以及服务业。  相似文献   
80.
Whilst many of us engage in supporting clinicians in identifying, appraising and using evidence, how many of us adopt the same approach to our own work? A recent survey by the UK LIS Research Coalition indicated that 60% of respondents use research reports as a source of information whilst a similar proportion of health library respondents use professional events such as conferences as a source of information. This summer sees the 6th International Evidence Based Library and Information Practice (EBLIP6) being held at the University of Salford, UK between 27th‐30th June which will go some way to satisfying this latter information need whilst the Health Information and Libraries Journal can help satisfy the need for research reports. Whatever you’re doing this summer, let’s make it evidence based.  相似文献   
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