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31.
Abstract High physical fitness in childhood and adolescence is positively associated with favourable health-related outcomes. Our aim was to examine the relationship between relatives' (father, mother, brother, sister, and best friend) physical activity engagement and encouragement on adolescents' physical fitness. Adolescents were part of the HELENA study, a multi-centre study conducted in 10 cities from nine European countries in 2006-2008. Participants were 3288 adolescents (48% boys, 52% girls) aged 12.5-17.5 years with valid data on at least one of the three fitness variables studied: muscular strength (standing long jump), speed/agility (4×10 m shuttle run), and cardiorespiratory fitness (20 m shuttle run). The adolescents reported their relatives' physical activity engagement and encouragement. Analysis of covariance showed that relatives' physical activity engagement (father, mother, brother, and best friend) was positively related to cardiorespiratory fitness (P?相似文献   
32.
Both China and India have been experiencing a historical take-off in the use of intellectual property rights (IPR). In terms of trademark applications filed with domestic IP offices in 2009, the evidence demonstrates that China now ranks 1st worldwide and India 5th, while for patent filings China ranks 3rd worldwide and India ranks 9th. This performance is remarkable as both China and India experienced negligible demand for IPR protection as recently as two decades ago. The IPR take up trends in these two countries are analyzed in detail, highlighting the structure of patent and trademark demand since 1990. Specifically, the available series are broken down and analyzed according to: (i) national versus foreign origin of patents and trademarks; (ii) technological (IPC) and trademark (NICE) classes; and (iii) the major individual patent users in each country. The data used refers to applications in the Chinese and Indian IP offices although the demand from residents of these two countries in both the international and other national systems is also assessed. Beyond the existing momentum in IPR registrations by China and India and their capacity to maintain it into the near future, the paper addresses practical questions about the strategies, motives and benefits behind the current trends. In particular, we seek to evaluate the capacity of both China's and India's National Innovation Systems to internalize the potential returns of this increasing demand for IPR. The insight reached finds that should both China and India sustain their current IPR growth rates, they will be able to catch up with the most advanced economies within the time span of a few decades.  相似文献   
33.
This study explored the early development of expert athletes compared to a group of athletes that did not achieve an expert level of performance despite being involved in youth events with their national squads. In particular, the activities, training patterns, and psychosocial influences that characterized their paths in competitive sports were examined. Male and female participants (N?=?42) from different sports were interviewed. Overall, athletes showed several commonalities. However, experts were selected to national squads later and also started thinking about investing in becoming elite athletes later. Non-experts revealed more parental pressure and less individual training with coaches.  相似文献   
34.
In this article we examine empirical evidence on the criterion, predictive, transfer, and fairness aspects of validity of a large-scale language arts performance assessment, referred to as the Performance Assignment (PA). We use multilevel models to avoid biased inferences that might result from the naturally nested data. Specifically, we examine the relationships of the assessment with the Stanford Achievement Test, 9th Edition and the California High School Exit Examination. The results indicate that the measures are related, that students demonstrate a degree of transfer, and that the language arts PA is relatively more fair than comparison assessments. The results are robust to various model specifications and demonstrate that benefits do not accrue to all students equally.  相似文献   
35.
36.
This paper proves a general structural property of the wavelet tree for a given seminorm in the context of the wavelet packet transform method. This structural property can be used in denoising algorithms of different applications to guarantee the optimality of novel search strategies. The property holds for any input signals using any orthogonal analysing wavelet families. The property holds for any norms, which results to be a convex function through the wavelet tree. Using a defined norms, seminorms or pseudonorms, this property can be used to detect incoherent parts of an input signal by using the minimal depth of the tree. In this sense the proposed denoising procedure works without thresholds for the localisation of different kinds of noise, as well as for a stop criterium for an optimal representation of the incoherency. The proof of this property is performed by mathematical induction and the demonstration is based on orthonormality with the help of the multiresolution framework aspects of the wavelets packet tree. The Theorem is independent of the definition of the adopted norm and of the incoherent part of an input signal. In this sense, the discovered property is a general one, which is related to any norm and any nature of the signal incoherence. It can be used in different applications, in which a minimum of a norm is required to be calculated through the wavelet tree.  相似文献   
37.
Trajectories of stability and change in bullying roles were examined through a longitudinal prospective study of 916 school students followed up biannually from age 11 to 17. Perpetrators and victims had relatively stable trajectories with most of the children remaining in the same role over time or becoming uninvolved. Bully/victim was the most unstable role with frequent transitions to perpetrators or victims. Developmental change in bullying roles was found with a decrease in physical forms over time in bullies and victims but with persistently high perpetration and victimization in bully/victims. These findings open new horizons in research and practice related to bullying and can be useful for its early detection or design of targeted interventions.  相似文献   
38.
Health information is readily available and easily obtained from a variety of media and interpersonal sources. Although several studies have examined health-related information seeking, a comprehensive validation study of this measure is still needed. This study uses a longitudinal cohort study of Israeli university students (N = 800) aged 18–30, and a cross-sectional sample of U.S. college students (N = 498) to validate measures of information seeking about the nonmedical use of two drugs (marijuana and amphetamines) from a range of media and interpersonal sources. Information seeking measures for both drug types showed good convergent, discriminant, nomological, and test-retest validity. Results offer support for the use of these measures as valid indicators of the constructs for which they were designed. Implications for the use of these measures in future research are discussed.  相似文献   
39.
Using longitudinal data from a cohort of middle school students from a large school district, we estimate separate "value-added" teacher effects for two subscales of a mathematics assessment under a variety of statistical models varying in form and degree of control for student background characteristics. We find that the variation in estimated effects resulting from the different mathematics achievement measures is large relative to variation resulting from choices about model specification, and that the variation within teachers across achievement measures is larger than the variation across teachers. These results suggest that conclusions about individual teachers' performance based on value-added models can be sensitive to the ways in which student achievement is measured.  相似文献   
40.
Previous research has suggested that children in the early grades of primary school do not have much awareness of morphemes. In this study, a priming paradigm was used to try to detect early signs of morphological representation of stems through a spelling task presented to Portuguese children (N = 805; age range 6–9 years). Primes shared the stem with the targets and contained well-articulated, stressed vowels; the stems of the target words and pseudo-words contained non-stressed schwa vowels, which typically result in spelling difficulties. If priming proved effective, the well-articulated vowels in the prime should result in an improvement in the spelling of the schwa vowels. Primes were presented in two conditions: in only-oral or in oral-plus-written form. Effectiveness of priming was assessed by comparison with a no-priming condition. For both words and pseudowords, there was a significant interaction between priming effects and grade. No priming effects were detected in 6- and 7-year-old children; oral-plus-written priming produced higher rates of correct vowel spelling for 8- and 9-year-olds; only-oral priming was effective in improving the vowel spelling of 9-year-olds. Thus older children can use morphological information under priming conditions when the prime and the target are not phonologically transparent but there is no evidence to suggest that younger children do so.  相似文献   
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