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1.
Accumulating evidence indicates the critical importance of cerebrovascular dysfunction in the pathogenesis of Alzheimer''s disease (AD). However, systematic comparative studies on the precise brain vasculature of wild-type and AD model mice are still rare. Using an image-optimization method for analysing Micro-Optical Sectioning Tomography (MOST) data, we generated cross-scale whole-brain 3D atlases that cover the entire vascular system from large vessels down to smallest capillaries at submicron resolution, for both wild-type mice and a transgenic (APP/PS1) mouse model of AD. In addition to distinct vascular patterns in different brain regions, we found that the main vessels of the molecular layer of the hippocampal dentate gyrus (DG-ml) undergo abrupt changes in both diameter and branch angle, spreading a unique comb-like pattern of capillaries. By using a quantitative analysis workflow, we identified in the hippocampus of AD mice an overall reduction of the mean vascular diameter, volume fraction and branch angle, with most significant impairment in the DG-ml. In addition, virtual endoscopy revealed irregular morphological features in the vessel lumen of the AD mice, potentially contributing to the impairment of blood flow. Our results demonstrate the capability of high-resolution cross-scale evaluation of brain vasculature and underscore the importance of studying hippocampal microcirculation for understanding AD pathogenesis.  相似文献   
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Virtual microscopy (VM) is a widely used teaching method in Medical Education in many developed countries. In Brazil, however, this is not the case for most medical schools, considering Brazilian social inequality and uneven access to technology. Recently, the Covid-19 pandemic has also challenged Universities to seek and make a transition toward more effective methods of full-time online education. Thus, the main goal of this work was to verify student's perception and academic performance, assessed upon VM implementation in a Brazilian Medical School. Ribeirao Preto Medical School students answered a 26-question survey with regards to optical microscopy (OM) and VM. Academic performance was compared between participants that were (year of 2019) or were not (year of 2015) exposed to VM. Taken the results together, subjective impressions such as handling, suitability, learning effectiveness, and pleasure using the tools, have shown a higher score for virtual microscopy (median = 29), when compared to optical microscopy (median = 24) with a P-value < 0.001 by Wilcoxon rank test, upon measurement using an ordinal scale. Regarding academic performance, no statistically significant differences were found between groups (P-value = 0.38, Cohen's d = 0.19). Therefore, VM proved to be adequate to the Brazilian medical education in light of Brazilian social contexts and Covid-19 pandemic.  相似文献   
3.
Game-based learning can have a positive impact on medical education, and virtual worlds have great potential for supporting immersive online games. It is necessary to reinforce current medical students' knowledge about radiological anatomy and radiological signs. To meet this need, the objectives of this study were: to design a competition-based game in the virtual world, Second Life and to analyze the students' perceptions of Second Life and the game, as well as to analyze the medium-term retention of knowledge and the potential impact on the final grades. Ninety out of 197 (45.6%) third-year medical students voluntarily participated in an online game based on self-guided presentations and multiple-choice tests over six 6-day stages. Participants and non-participants were invited to perform an evaluation questionnaire about the experience and a post-exposure knowledge test. Participants rated the experience with mean scores equal to or higher than 8.1 on a 10-point scale, highlighting the professor (9.5 ± 1.1; mean ± SD) and the virtual environment (8.9 ± 1.1). Participants had better results in the post-exposure test than non-participants (59.0 ± 13.5 versus 45.3 ± 11.5; P < 0.001) and a lower percentage of answers left blank (6.7 ± 8.4 versus 13.1 ± 12.9; P = 0.014). Competitive game-based learning within Second Life is an effective and well-accepted means of teaching core radiological anatomy and radiological signs content to medical students. The higher medium-term outcomes obtained by participants may indicate effective learning with the game. Additionally, valuable positive perceptions about the game, the educational contents, and the potential benefit for their education were discovered among non-participants.  相似文献   
4.
Virtual microscopy (VM) has been utilized to improve students' learning experience in microscope laboratory sessions, but minimal attention has been given to determining how to use VM more effectively. The study examined the influence of VM on academic performance and teacher and student perceptions and compared laboratory test scores before and after VM incorporation. A total of 662 third-year students studying histology and 651 fourth-year students studying pathology were divided into two groups. The light microscopy (LM) group used a light microscope in 2014 and 2015, while the LM + VM group used the VM platform and a light microscope in 2016 and 2017. Four factors positively predict laboratory scores (R square, 0.323; P < 0.001): (i) the pathology course and test-enhanced learning, (ii) the VM platform and experience, (iii) medical students and lecture scores, and (iv) female students. The LM + VM group exhibited less score variability on laboratory examinations relative to their mean than the LM group. The LM + VM group was also associated with fewer failing grades (F grade; odds ratio, 0.336; P < 0.001) and higher scores (A grade; odds ratio, 2.084; P < 0.001) after controlling for sex, school, course, and lecture grades. The positive effect of the VM platform on laboratory test grades was associated with prior experience using the VM platform and was synergistic with more interim tests. Both teachers and students agreed that the VM platform enhanced laboratory learning. The incorporation of the VM platform in the context of test-enhanced learning may help more students to master microscopic laboratory content.  相似文献   
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The development of three-dimensional learning among all K-12 student demographics remains a prominent goal for the field of science education. However, substantial research in science teacher education for urban populations showcases hurdles to overcome in order to achieve this goal, particularly for elementary teachers. Research shows that urban elementary teachers are often ill-prepared to develop a type of science pedagogy responsive to students' learning needs. The fidelity of such pedagogies that these teachers adhere to when trying to implement such a requested content–relationality between these populations and how their local contexts can be used as sites to learn science in relevant ways are often not fully realized, as well. Given that science achievement gaps exhibit racial disparities starting in primary grades and attitudes toward science have been shown to affect academic achievement and motivation, we argue that one way to ameliorate, in at least an incremental way, this disparity is to design novel learning experiences to prime students to see the relevancy of science in their local contexts before such three-dimensional designed learning is set to occur. In this research, we leveraged the immersive nature of Virtual Reality 360 videos and present a design-based research iteration testing how this novel technologically enhanced learning experience may have influenced close to 400 urban elementary students' attitudes toward science around those attitudes labeled as “behavioral beliefs” by the field. Using a concurrent, convergent mixed-methods design with a two-way multivariate analysis of covariance quantitative data set triangulated with students' qualitative self-reports that were transformed into quantitative preponderances in graphic form, the data support that our design iteration emphasizing the importance of context as a design focus can prime students who struggle to see science as relevant to change their attitudes. Implications are discussed around relationality, novel technological affordances, and the use of local contexts as learning resources.  相似文献   
7.
基于虚拟现实技术的救助船对外消防培训仿真系统   总被引:1,自引:0,他引:1  
针对救助船消防训练中存在的海况复杂,对外消防炮射流受风影响大,往往无法准确控制其射向目标区域的问题,在理想状态下射流理论的基础上探究风对射流轨迹的影响,建立自然风条件下射流轨迹的数学模型,模拟对外消防炮射流的运动情况。应用3ds Max构建船舶模型,用Unity3D构建救助船在面临大风浪、遇险船着火等状况时对外消防系统的工作场景,提出一种精确构建粒子系统轨迹的方法,使射流模型能精确体现在场景中。通过虚拟现实设备能实现救助船对外消防培训仿真系统的立体显示和人机交互,起到更好的虚拟仿真和培训效果。  相似文献   
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肖花  刘春年  郭韫丽 《现代情报》2016,36(11):32-36
文章基于虚拟社区环境,阐述了突发事件下用户应急信息行为表现特征,剖析基于虚拟社区的用户应急信息行为实施的必要性,划分基于虚拟社区的用户应急信息行为构成维度,分析突发事件中虚拟社区用户应急信息行为过程,并提出突发事件下基于虚拟社区的用户应急信息行为的优势所在。  相似文献   
10.
虚拟多角化的合作机制与运作模式探析   总被引:1,自引:0,他引:1  
虚拟多角化是以功能为介体通过非产权合作联系到一起的运作整体。本文在对虚拟多角化的内涵与特征分析的基础上,探讨了虚拟多角化的合作代理、自私代理合作机制,进而提出了虚拟多角化的“哑铃型”与“联合体”两种运作模式及其对应的具体运作形式,最后阐述了虚拟多角化对家电业和轻纺业的实践启示。  相似文献   
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