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11.
Continued advancement in the field of physical activity and health promotion relies heavily on the synthesis of rigorous scientific evidence. As such, systematic reviews and meta-analyses of randomized controlled trials have led to a better understanding of which intervention strategies are superior (i.e., produce the greatest effects) in physical activity-based health behavior change interventions. Indeed, standard meta-analytic approaches have allowed researchers in the field to synthesize relevant experimental evidence using pairwise procedures that produce reliable estimates of the homogeneity, magnitude, and potential biases in the observed effects. However, pairwise meta-analytic procedures are only capable to discerning differences in effects between a select intervention strategy and a select comparison or control condition. In order to maximize the impact of physical activity interventions on health-related outcomes, it is necessary to establish evidence concerning the comparative efficacy of all relevant physical activity intervention strategies. The development of network meta-analysis (NMA)—most commonly used in medical-based clinical trials—has allowed for the quantification of indirect comparisons, even in the absence of direct, head-to-head trials. Thus, it stands to reason that NMA can be applied in physical activity and health promotion research to identify the best intervention strategies. Given that this analysis technique is novel and largely unexplored in the field of physical activity and health promotion, care must be taken in its application to ensure reliable estimates and discernment of the effect sizes among interventions. Therefore, the purpose of this review is to comment on the potential application and importance of NMA in the field of physical activity and health promotion, describe how to properly and effectively apply this technique, and suggest important considerations for its appropriate application in this field. In this paper, overviews of the foundations of NMA and commonly used approaches for conducting NMA are provided, followed by assumptions related to NMA, opportunities and challenges in NMA, and a step-by-step example of developing and conducting an NMA.  相似文献   
12.
利用核密度分析、巴雷托截取法和多元回归分析等方法,对我国大学生高水平排球队空间分布特征和影响因素进行分析。主要结论有:大学生高水平排球队的数量呈波动上升趋势;在规模结构上,大学生高水平排球队数量规模的省际分布呈现倒“金字塔”结构,而配比规模的省际分布呈现“金字塔”结构,且极不平衡;在空间格局上,具有显著的区域差异,表现出东部区域较多;在集聚特征上,大学生高水平排球队主要分布在直辖市和省会城市,主要集聚在京津翼地区和长江流域,其他地区比较分散;在空间竞技实力上,具有显著的区域不平衡性,呈现“南弱北强”的特征;影响大学生高水平排球队空间分布的主要因素有高校招生条件、本科院校数量、经济发展实力和体育发展水平。  相似文献   
13.
针对多旋翼无人机目标的识别问题,提出一种基于伽柏(Gabor)变换的瞬时频率估计与快速傅里叶变换(FFT)相结合的微多普勒特征提取算法。首先建立多旋翼无人机旋翼回波模型,并通过仿真分析叶片数目、旋翼转速和初始相位等参数对微多普勒特征的影响,利用Gabor变换得到时频特征。在此基础上通过瞬时频率极大值法提取微多普勒频率,并对瞬时频率采用FFT提取旋翼数和转动频率,从而获得叶片长度估计值。实测数据验证了该算法较为准确地提取无人机的微多普勒参数。  相似文献   
14.
随着信息技术的快速发展和教育理念的不断更新,符合信息化教学时代背景的学习型微信公众平台——微助教应运而生,成为教育界的新星,从而真正实现个性化教学,为教学改革注入新的活力。文章将对微助教的功能特色以及利用其辅助大班课堂教学的优势进行简单的总结概述,并对其做出简要的分析,提出一些理解与看法。  相似文献   
15.
ABSTRACT

This article suggests that situations in which multiple research teams are convened under similar conditions present an opportunity to discover factors that lead to productive collaboration. It argues that social network analysis of research team outputs becomes more valuable when paired with data about research participant perceptions; and that any variables used as indicators of collaboration need to be calibrated using datasets from multiple studies with cross-team comparisons. The article provides an example of the kind of methodology needed to achieve this, describing a study with data from four research teams based at an Australian university campus, reporting their research performance over four years under conditions in which many variables were controlled and with results augmented by a survey of participant perceptions. Findings from the study indicate that there were exceptions to hypothesized associations between participant perceptions of collaboration and specific social network analysis measures over co-authorship data. The article suggests that, given the methodological challenges of studying research teams in the field, multiple datasets combining findings such as those in the present study are a path towards the development of indicators of productive higher education research collaboration.  相似文献   
16.
首先对中国知网数据库中收录的以警察体育为主题的文献时序分布进行梳理,通过论文发表时间与数量的变量关系对比,分析揭示该研究领域的历史脉络、发展速度以及演变规律。随后利用信息可视化软件Bibexcel绘制出警察体育研究领域的核心作者、研究机构、高被引文献的知识图谱,阐释该领域的研究结构、力量分布以及合作平台建设等情况。最后运用词频分析、共词聚类和可视化法生成关键词共现网络图谱,挖掘、提炼文献数据背后的规律与逻辑,捕捉警察体育研究领域中的研究热点和前沿动态,并在此基础上深入探讨警察体育未来研究的基本趋势和发展方向。  相似文献   
17.
Handwriter identification aims to simplify the task of forensic experts by providing them with semi-automated tools in order to enable them to narrow down the search to determine the final identification of an unknown handwritten sample. An identification algorithm aims to produce a list of predicted writers of the unknown handwritten sample ranked in terms of confidence measure metrics for use by the forensic expert will make the final decision.Most existing handwriter identification systems use either statistical or model-based approaches. To further improve the performances this paper proposes to deploy a combination of both approaches using Oriented Basic Image features and the concept of graphemes codebook. To reduce the resulting high dimensionality of the feature vector a Kernel Principal Component Analysis has been used. To gauge the effectiveness of the proposed method a performance analysis, using IAM dataset for English handwriting and ICFHR 2012 dataset for Arabic handwriting, has been carried out. The results obtained achieved an accuracy of 96% thus demonstrating its superiority when compared against similar techniques.  相似文献   
18.
Aspect-based sentiment analysis aims to determine sentiment polarities toward specific aspect terms within the same sentence or document. Most recent studies adopted attention-based neural network models to implicitly connect aspect terms with context words. However, these studies were limited by insufficient interaction between aspect terms and opinion words, leading to poor performance on robustness test sets. In addition, we have found that robustness test sets create new sentences that interfere with the original information of a sentence, which often makes the text too long and leads to the problem of long-distance dependence. Simultaneously, these new sentences produce more non-target aspect terms, misleading the model because of the lack of relevant knowledge guidance. This study proposes a knowledge guided multi-granularity graph convolutional neural network (KMGCN) to solve these problems. The multi-granularity attention mechanism is designed to enhance the interaction between aspect terms and opinion words. To address the long-distance dependence, KMGCN uses a graph convolutional network that relies on a semantic map based on fine-tuning pre-trained models. In particular, KMGCN uses a mask mechanism guided by conceptual knowledge to encounter more aspect terms (including target and non-target aspect terms). Experiments are conducted on 12 SemEval-2014 variant benchmarking datasets, and the results demonstrated the effectiveness of the proposed framework.  相似文献   
19.
Zero-shot object classification aims to recognize the object of unseen classes whose supervised data are unavailable in the training stage. Recent zero-shot learning (ZSL) methods usually propose to generate new supervised data for unseen classes by designing various deep generative networks. In this paper, we propose an end-to-end deep generative ZSL approach that trains the data generation module and object classification module jointly, rather than separately as in the majority of existing generation-based ZSL methods. Due to the ZSL assumption that unseen data are unavailable in the training stage, the distribution of generated unseen data will shift to the distribution of seen data, and subsequently causes the projection domain shift problem. Therefore, we further design a novel meta-learning optimization model to improve the proposed generation-based ZSL approach, where the parameters initialization and the parameters update algorithm are meta-learned to assist model convergence. We evaluate the proposed approach on five standard ZSL datasets. The average accuracy increased by the proposed jointly training strategy is 2.7% and 23.0% for the standard ZSL task and generalized ZSL task respectively, and the meta-learning optimization further improves the accuracy by 5.0% and 2.1% on two ZSL tasks respectively. Experimental results demonstrate that the proposed approach has significant superiority in various ZSL tasks.  相似文献   
20.
A named professional with responsibility for overseeing and coordinating the educational inclusion of pupils with special educational needs and disabilities has become an important school role in many countries. In England, the SENCO (special educational needs coordinator) became a mandatory role in 1994, and associated mandatory training was introduced in 2009. A questionnaire survey of 618 in-training and actual SENCOs revealed that their motivating interest in becoming a SENCO varied. An exploratory factor analysis of 32 items covering different interests in the role yielded four interest factors in becoming a SENCO: outward-facing factors (‘inclusion’ and ‘high-quality provision’) and inward-facing factors (‘educational and professional development’ and ‘leadership voice and status’). The outward-facing factors were viewed as more important to respondents than the inward-facing factors. Interest factors did not interact with organisational variables, including age group taught and school quality. Nevertheless, younger SENCOs and those engaged in training were more motivated by educational and professional development. SENCOs holding school leadership contracts were more motivated in developing leadership voice and status compared with their classroom teacher peers. Moreover, there was a significant overall difference with women reporting a higher interest than men across all factors.  相似文献   
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