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151.
Konstantinos D. Tambalis Demosthenes B. Panagiotakos Glykeria Psarra Stelios Daskalakis Stavros A. Kavouras Nickos Geladas 《European Journal of Sport Science》2016,16(6):736-746
The aim of the this study was to establish age- and gender-specific physical fitness normative values and to compare percentiles and Z scores values in a large, nationwide sample of Greek children aged 6–18 years. From March 2014 to May 2014, a total of 424,328 boys and girls aged 6–18 years who attended school in Greece were enrolled. The studied sample was representative, in terms of age–sex distribution and geographical region. Physical fitness tests (i.e. 20?m shuttle run test (SRT), standing long jump, sit and reach, sit-ups, and 10?×?5?m SRT) were performed and used to calculate normative values, using the percentiles of the empirical distributions and the lambda, mu, and sigma statistical method. Normative values were presented as tabulated percentiles for five health-related fitness tests based on a large data set comprising 424,328 test performances. Boys typically scored higher than girls on cardiovascular endurance, muscular strength, muscular endurance, and speed/agility, but lower on flexibility (all p values <0.001). Older boys and girls had better performances than younger ones (p?0.001). Physical fitness tests' performances tended to peak at around the age of 15 years in both sexes. The presented population-based data are the most up-to-date sex- and age-values for the health-related fitness of children and adolescents in Greece and can be used as standard values for fitness screening and surveillance systems and for comparisons among the same health-related fitness scores of children from other countries similar to Greece. Schools need to make efforts to improve the fitness level of the schoolchildren through the physical education curriculum to prevent cardiovascular risk. 相似文献
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153.
Walid Briki Keith D. Markman Guillaume Coudevylle Stéphane Sinnapah Olivier Hue 《European Journal of Sport Science》2016,16(3):350-357
The present study examined the influence of momentum sequence (positive vs. negative) and environmental climate (hot–wet vs. neutral) on supporters’ (i.e. virtual observers’) reported levels of perceived psychological momentum (PM) during a simulated cycling competition. Participants supported one of two competing cyclists involved in a race that was displayed on a screen in a lecture hall. The race scenario was manipulated so that the supported cyclist appeared to undergo either a positive or negative momentum sequence. In addition, participants were either exposed to a hot–wet environmental climate or to a neutral environmental climate while observing the race scenario. According to the results, reported levels of PM were higher in the positive momentum sequence condition than in the negative momentum sequence condition, consistent with the notion that supporters’ PM is influenced by a positivity bias, and reported levels of PM were also found to be higher in the hot–wet climate condition than in the neutral climate condition, consistent with the notion that environmental climate is a contextual factor that influences PM through the operation of a causal augmenting mechanism. 相似文献
154.
Richard James 《高等教育研究与发展》1995,14(2):185-199
The academic award restructuring of 1991 established a trial period for academic staff appraisal for the purposes of staff development. The trend in Australia towards more formal performance management for academics has occurred during a period of substantial change to the structure of higher education and institutional management, and brought debate on whether appraisal, for either summative purposes (where performance assessment is for remuneration or promotion purposes) or formative purposes (where the emphasis is on planning personal development), is appropriate for academic staff. Arguments have been put forward for the benefits of appraisal processes with primarily developmental intent. Thus far there have been reports of the characteristics and processes of appraisal schemes, but less data on outcomes; in particular, little evidence to indicate the extent to which schemes lead to worthwhile staff development. This paper reports selected findings of a study of the evolving appraisal scheme of The University of Melbourne. The study was conducted after the scheme's second year of operation by the Centre for the Study of Higher Education which played an advisory role in an internal review of the scheme. The findings reveal some uncertainty among staff about the intentions of the scheme, and tensions between summative and formative purposes, perhaps not surprising given the contentious issue which staff appraisal has been in higher education. Nevertheless, positive outcomes were identified, but possibly too few to claim that the scheme was fully achieving a developmental objective. These findings raise questions about the effectiveness of academic staff appraisal nationally and suggest that it is time to reconsider the policy linkage between appraisal and staff development. 相似文献
155.
This paper addresses a dynamic portfolio investment problem. It discusses how we can dynamically choose candidate assets, achieve the possible maximum revenue and reduce the risk to the minimum level. The paper generalizes Markowitz's portfolio selection theory and Sharpe's rule for investment decision. An analytical solution is presented to show how an institutional or individual investor can combine Markowitz's portfolio selection theory, generalized Sharpe's rule and Value-at-Risk(VaR) to find candidate assets and optimal level of position sizes for investment (dis-investment). The result shows that the generalized Markowitz's portfolio selection theory and generalized Sharpe's rule improve decision making for investment. 相似文献
156.
D P Sen Gupta 《Resonance》2007,12(3):54-69
Alternating Current (AC) is used all over the world today. In India we use AC at 50 Hz (cycles per second) and in USA and
Canada at 60 Hz. During the latter part of the 19th century, even during the early part of the 20th century, Direct Current
or DC was widely used. Had we continued with DC, electricity would not have been as widely available as it is today and its
use would have been cumbersome, costly and severely restricted. We owe it mainly to the Serbian genius Nikola Tesla that electricity
has reached almost every nook and corner of most continents. 相似文献
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159.
1IntroductionRecent advances in wireless communication,digitallibrary,distributed multi media,massive storage,andmobile computing technologies are sti mulating the de-velopment of mobile multi media digital library systems(M2DLS)that allow mobile clients to access multi me-dia material anywhere and anyti me over a cellular ra-dio network[1,2].In M2DLS,multi media objects,ingeneral,can be composed of multiple media streamssuch as audio and video,whose retrieval must proceedso as to not only … 相似文献
160.