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91.
In this study we examined variations of the nonequivalent groups equating design for tests containing both multiple-choice (MC) and constructed-response (CR) items to determine which design was most effective in producing equivalent scores across the two tests to be equated. Using data from a large-scale exam, this study investigated the use of anchor CR item rescoring (known as trend scoring) in the context of classical equating methods. Four linking designs were examined: an anchor with only MC items, a mixed-format anchor test containing both MC and CR items; a mixed-format anchor test incorporating common CR item rescoring; and an equivalent groups (EG) design with CR item rescoring, thereby avoiding the need for an anchor test. Designs using either MC items alone or a mixed anchor without CR item rescoring resulted in much larger bias than the other two designs. The EG design with trend scoring resulted in the smallest bias, leading to the smallest root mean squared error value. 相似文献
92.
Relations between early family risk, children's behavioral regulation, and academic achievement 总被引:3,自引:0,他引:3
This study examined relations among early family risk, children's behavioral regulation at 54 months and kindergarten, and academic achievement in first grade using data on 1,298 children from the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development. Family risk was indexed by ethnic minority status, low maternal education, low average family income from 1 - 54 months, and high maternal depressive symptoms from 1 - 54 months. Results of structural equation modeling indicated that minority status, low maternal education, and low family income had significant negative effects on reading, math, and vocabulary achievement in first grade. Modest indirect effects were also found from ethnicity, maternal education, and maternal depressive symptoms, through 54-month and kindergarten behavioral regulation to first-grade achievement. Discussion focuses on the importance of behavioral regulation for school success especially for children facing early risk. 相似文献
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Starting in the 1950s Luna B. Leopold and M. Gordon Wolman transformed the field of geomorphology with quantitative and process-orientated studies designed to understand landscape adjustments to temporal and spatial changes in sediment supply and streamflow. By integrating fundamental science with keen observations they developed the first comprehensive and mechanistic understanding of rivers and floodplains. Their research has not only provided a quantitative framework for understanding landscape evolution, it is a cornerstone of modern water resource management and environmental impact analysis. Specific research areas included quantifying: (1) the “hydraulic geometry” of rivers; (2) the morphology and processes of rivers; (3) channel networks and the longitudinal profiles of rivers; (4) processes controlling floodplain formation; (5) the magnitude and frequency of geomorphic processes; and (6) the cycle of sedimentation in response to urban development. Much of this research was published in seven co-authored articles and in a widely used 1964 book that they co-authored with John Miller, Fluvial Processes in Geomorphology. While their contributions are synergistically linked and stem from their co-authored papers, their individual contributions are distinct and extend over 50 years. For these accomplishments, Luna Leopold and M. Gordon Wolman were awarded the 2006 Benjamin Franklin Medal in Earth and Environmental Science. 相似文献
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Frederick J Friend 《图书情报工作》2006,50(1):24-27
New opportunities presented by technological developments are being realised but more can be achieved in opening access to scientific reports and data. Funding agencies and universities are beginning to realise the benefits from an open access model for the dissemination of research results. European funding agencies and universities are following two strategies towards open access, the deposit of research reports in repositories and the conversion of journals to an open access business model. Various public statements have been made in support of open access, and several organizations-such as JISC in the UK-are undertaking work to assist all stakeholders in scholarly communication in introducing beneficial changes. 相似文献
99.
Jeffrey William Frederick Aldous Bryna Catherine Rose Chrismas Ibrahim Akubat Charlotte Anne Stringer Grant Abt 《European Journal of Sport Science》2019,19(2):156-165
This investigation examined the effects of three pre-match and half-time cooling manoeuvres on physical performance and associated physiological and perceptual responses in eight University soccer players during a non-motorised treadmill based individualised soccer-specific simulation [intermittent soccer performance test (iSPT)] at 30°C. Four randomised experimental trials were completed; following 30-min (pre-match) and 15-min (half-time) cooling manoeuvres via (1) ice slurry ingestion (SLURRY); (2) ice-packs placed on the quadriceps and hamstrings (PACKS); (3) mixed-methods (MM; PACKS and SLURRY concurrently); or no-cooling (CON). In iSPT first half, a moderate increase in total (Mean?±?Standard Deviation: 108?±?57 m, qualitative inference: most likely, Cohen’s d: 0.87, 90%CL: ±0.31), high-speed (56?±?46 m, very likely, 0.68?±?0.38) and variable run (15?±?5 m, very likely, 0.81?±?0.47) distance covered was reported in MM compared with CON. Additionally, pre-match reductions in thermal sensation (–1.0?±?0.5, most likely, –0.91?±?0.36), rectal (–0.6?±?0.1°C, very likely, –0.86?±?0.35) and skin temperature (–1.1?±?0.3°C, very likely, –0.88?±?0.42) continued throughout iSPT first half. Physical performance during iSPT first half was unaltered in SLURRY and PACKS compared to CON. Rectal temperature was moderately increased in SLURRY at 45-min (0.2?±?0.1°C, very likely, 0.67?±?0.36). Condition did not influence any measure in iSPT second half compared to CON. Only MM pre-match cooling augmented physical performance during iSPT first half, likely due to peripheral and central thermoregulatory factors favourably influencing first half iSPT performance. Further practical half-time cooling manoeuvres which enhance second half performance are still required. 相似文献
100.
We study the incentives that museums face in determining how much resources to invest in the protection of their artwork from theft. We present and analyze a game-theoretic model of art heists that accounts for the strategic interactions between museums’ and art thieves’ decisions and that incorporates several key features of the black market for stolen art. We find that the equilibrium level of security museums choose need not be monotonic in the true market value or the black market value of artwork, i.e., increasing the value of an art piece—whether it is the true market value or the black market value—does not necessarily lead museums to invest more in protecting their artwork. The effects of parameter changes in the model that reflect a shift of public policy depend critically on what type of policy change is considered. For instance, an increase in the penalty imposed for committing art theft cannot raise the amount of theft in equilibrium and could in fact lead museums to increase their level of security. On the other hand, investing more resources on law enforcement agencies so that they are better able to solve art crimes can actually increase the amount of theft in equilibrium by causing museums to spend less on security. 相似文献