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161.
Ana Lilia Laureano-Cruces Javier Ramírez-Rodríguez Fernando de Arriaga Rafael Escarela-Pérez 《Interactive Learning Environments》2013,21(2):95-118
Intelligent learning systems (ILSs) have evolved in the last few years basically because of influences received from multi-agent architectures (MAs). Conflict resolution among agents has been a very important problem for multi-agent systems, with specific features in the case of ILSs. The literature shows that ILSs with cognitive or pedagogical agents are prone to arbitration methods, where as ILSs with reactive agents are much in favor of control mechanisms. For these kind of systems, different control types are proposed based on the different stimuli that these agents will receive. These stimuli are aspects to be evaluated during the teaching/learning process such as: (1) error analysis, (2) learning styles, (3) analogies, (4) social aspects, etc. The paper reviews several ILSs, related to our work; different control mechanisms are proposed to solve the agents' intervention conflicts. Finally, the use of several mechanisms is exemplified by the results of a specific ILS. 相似文献
162.
Thomas K. Bader Karin de Borst Karin Fackler Thomas Ters Susan Braovac 《Journal of Cultural Heritage》2013,14(5):377-388
Mechanical properties of wood at different length scales of its hierarchical structure are governed by structural and compositional properties on smaller length scales. This opens up the possibility to use microstructural data for estimating mechanical properties, which are difficult to assess by conventional, destructive testing but are nevertheless of high relevance for conservation practice. Herein, we investigate such microstructure-mechanics relationships for a particular example, namely the load bearing archaeological oak of the Oseberg Viking ship, displayed at the Viking Ship Museum in Oslo, Norway. In order to identify the effects of degradation on the mechanical behavior and their relations to the microstructure, recent oak specimens of different geographical origin (Norway and Austria) are investigated as well. Wood exhibits a cellular structure. Its cell walls are composed of an amorphous polymer matrix consisting of lignin and hemicelluloses and embedded, stiff cellulose fibers. At the cell level, experimental studies comprised microscopic investigations of the cellular structure, chemical analyses of the composition of the cell walls, as well as nanoindentation tests on single cell walls. The same samples were also analyzed on the macroscopic level, where additionally mass density and annual ring data were measured together with ultrasonic stiffnesses. The chemical data clearly indicate deterioration in the archaeological oak, affecting mainly hemicelluloses and amorphous cellulose. At the cell wall scale, however, this does not necessarily lead to a weaker material behavior. The nanoindentation modulus, as a measure of the cell wall stiffness, was found to even increase. This is counterintuitive to our understanding of the effects of chemical degradation. It might be due to possible modification of lignin in the Oseberg oak, and thus have a stronger effect on the indentation modulus than the concurrent weakening of the interfaces between the load-carrying cellulose fibers and the connecting cell wall matrix when analyzing wood at the microscopic level. A similar effect is also observed for the transversal stiffness of macroscopic samples, which increases. In tension-dominated loading modes, however, the degradation of the interfaces is the dominant effect, resulting for example in a considerable reduction of the macroscopic stiffness in longitudinal direction. This underlines the utmost relevance of the loading condition on the remaining load-carrying capacity of degraded wood. On the macroscale, effects of the geographical origin (i.e. growth conditions) on ring characteristics of the oak tissues override the effects of degradation on the mechanical behavior. They have to be carefully extracted in order to come up with conclusions on the effect of degradation from macroscopic test results. The identified microstructure-mechanics relationships provide the basis for–in further research steps–building mathematical models describing the relations between microstructural characteristics and macroscopic mechanical properties and, thereon, for structural analyses of historical wooden objects. 相似文献
163.
This article places universal service policy in telecommunications in Australia in an historical context. Given the dynamic growth in information technologies, universal service should be reconceptualized within a knowledge-based discourse critically linked to considerations for deepening participatory democracy. As a consequence of the discussion this article recommends that funding universal service obligations in telecommunications be based on the preferred notion of a maximally open democratic debate. The universal service obligation in telecommunications should be funded from consolidated revenue with its parameters set by democratic debate. 相似文献
164.
Management literature has identified high-skilled human capital as a crucial dimension of innovation processes at the firm level. In this study, we introduce an alternative view of human capital based on the tasks that firms’ workers perform. We propose a measure of cognitive analytical and interpersonal tasks: the degree of abstractism. We argue that the level of abstractism of a firm has an effect on a firm's propensity to innovate and on its product innovation performance. We hypothesize that while the degree of abstractism has a linear positive relationship with the propensity to innovate, the relationship between abstractism and product innovation performance follows an inverted u-shaped relationship. We find partial support to our hypotheses using data from more than six thousand Portuguese firms. We discuss how these results change our understanding of the relationship between human capital and innovation at the firm level. 相似文献
165.
Rebeca Fernandes Ferreira Lima Marcela Raffaelli Normanda Araujo de Morais Juliana P. Santana Carlos J. Nieto Silvia H. Koller 《Child development》2020,91(4):1237-1253
Trajectories of adjustment were examined in a sample of street-involved youth across a 1-year period. Participants (N = 113; Mage = 14.18 years; 80.5% male, 91% non-White) were recruited in three Brazilian cities. Interviews conducted at three time points included six measures of physical and psychological adjustment. Unconditional growth models revealed linear declines over time (i.e., improved adjustment) on three indicators: health symptoms, sexual risk behaviors, and negative affect. There were no linear changes in drug use, positive affect, or life satisfaction. Conditional growth models revealed few significant effects for age or gender, but ratings of stressful life events moderated longitudinal changes in health symptoms, drug use, and negative affect. Implications for practice, policy, and theory are discussed. 相似文献
166.
Luiz Octávio Gavião Annibal Parracho Sant’Anna Gilson Brito Alves Lima Pauli Adriano de Almada Garcia 《Journal of sports sciences》2020,38(11-12):1221-1247
ABSTRACT The recruitment of athletes with limited resources is a global problem in professional sports. In US Major League Baseball, the experience of the Oakland Athletics’ general manager in the last decade turned his “Moneyball” model into a synonym of quantitative analysis in the transfer market of baseball players. His strategy focused on hiring players with outstanding technical skills but relatively low market value. This study adapted this model to the framework of a multiple criteria decision aid (MCDA), by selecting undervalued players who have complementary abilities. The novelty here refers to the joint use of four algorithms explored by the composition of probabilistic preferences (CPP) (i.e., ranking, classification, dynamic evaluation and regularity analysis) and their application to soccer player performance evaluation. The new model analysed the recent transfer of a left-back soccer player to Europe. The results indicated 12 opportunities for better investment, among 32 left and right-back players considered. Two years later, the value of the same player was considerably lower. He played only five matches in the 2018–2019 season, without scoring or providing any assists. On the other hand, the players better classified by the CPP-MB model presented higher performances and market values. 相似文献
167.
Nele Van de Mosselaer 《体育哲学杂志》2019,46(2):191-207
ABSTRACTVideogames often confront players with frustratingly difficult challenges, fearsome enemies, and tragic stories. As such, they can evoke feelings of failure, sadness, anger, and fear. Although these feelings are usually regarded as undesirable, many players seem to enjoy videogames which cause them. In this paper, I argue that player misery often originates from a fictional or lusory attitude which brackets game events from real-life, making the player’s emotions solely relevant within the game context. As they are part of the game themselves, these negative emotions can be enjoyed and easily relativized, since players can acknowledge that their cause is ‘only a game’. However, there are feelings of misery associated with the playing of videogames which are not caused by either the game’s fiction or challenge. In the last part of this paper, I describe a qualitatively different kind of player misery: one that is caused by elements that are not perceived as part of the game by the player, and is not bracketed from real life by a lusory or fictional attitude. 相似文献
168.
Voisin CE de la Varre C Whitener L Gartlehner G 《Health information and libraries journal》2008,25(3):198-207
BACKGROUND: Because of the expense of updating practice guidelines, recent attention has focused on approaches that can reliably assess any updating required. Shekelle et al. (Journal of the American Medical Association 2001, 286, 1461-7) proposed using limited literature searches with expert involvement to reduce resources used in assessing whether a guideline needs updating. OBJECTIVES: This study compared Shekelle's method and the traditional systematic review method regarding comprehensiveness and effort. METHODS: Two research teams translated critical key questions on screening test treatments and outcomes to Medical Subjects Headings (MeSH) and search strategies. They refined Shekelle's method over three iterations, seeking greater efficiency. Using both methods independently, teams assessed the need to update six topics from the 1996 Guide to Clinical Preventive Services (US Preventive Services Task Force). Outcomes included completeness of study identification, importance of missed studies and effort involved. RESULTS: The revised review approach produced fewer citations than the traditional approach and saved time, identifying fewer eligible studies than the traditional approach. None of the studies missed was rated important by the experts consulted. CONCLUSIONS: The revised review approach provides an acceptable method for judging whether a guideline requires updating. Librarians were an integral part of the research process that streamlined the searches. 相似文献
169.
Theo Araujo Anke Wonneberger Peter Neijens Claes de Vreese 《Communication methods and measures》2017,11(3):173-190
Given the importance of survey measures of online media use for communication research, it is crucial to assess and improve their quality, in particular because the increasingly fragmented and ubiquitous usage of internet complicates the accuracy of self-reported measures. This study contributes to the discussion regarding the accuracy of self-reported internet use by presenting relevant factors potentially affecting biases of self-reports and testing survey design strategies to improve accuracy. Combining automatic tracking data and survey data from the same participants (N = 690) confirmed low levels of accuracy and tendencies of over-reporting. The analysis revealed biases due to a range of factors associated with the intensity of (actual) internet usage, propensity to multitask, day of reference, and the usage of mobile devices. An anchoring technique could not be proved to reduce inaccuracies of reporting behavior. Several recommendations for research practice follow from these findings. 相似文献
170.
POTTERING IN THE GARDEN? ON HUMAN FLOURISHING AND EDUCATION 总被引:1,自引:0,他引:1
Doret J. de Ruyter 《British Journal of Educational Studies》2004,52(4):377-389