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991.
Blog feed search aims to identify a blog feed of recurring interest to users on a given topic. A blog feed, the retrieval
unit for blog feed search, comprises blog posts of diverse topics. This topical diversity of blog feeds often causes performance
deterioration of blog feed search. To alleviate the problem, this paper proposes several approaches based on passage retrieval,
widely regarded as effective to handle topical diversity at document level in ad-hoc retrieval. We define the global and local
evidence for blog feed search, which correspond to the document-level and passage-level evidence for passage retrieval, respectively,
and investigate their influence on blog feed search, in terms of both initial retrieval and pseudo-relevance feedback. For
initial retrieval, we propose a retrieval framework to integrate global evidence with local evidence. For pseudo-relevance
feedback, we gather feedback information from the local evidence of the top K ranked blog feeds to capture diverse and accurate information related to a given topic. Experimental results show that our
approaches using local evidence consistently and significantly outperform traditional ones. 相似文献
992.
According to the life cycle model of technological evolution, after the emergence of a dominant design, technological product industries undergo an “era of incremental change.” This era of incremental change is not well understood in the existing literature. Although the period is typically characterized in terms of stability and minimal innovation, we find that the era of incremental change can be actually quite dynamic. Through our research into the period of time following the emergence of a dominant design in automotive emission control systems, we find that the overall product innovation in the industry did not decline immediately following the dominant design, and increased throughout the era of incremental change. Further, we find that firms maintain their attention on the same core components that they innovated upon before the dominant design, but that these components make up less of the overall proportion of total innovation throughout the era of incremental change. Finally, we found that the concentration of innovating firms in the industry increases immediately following the dominant design, and this concentration decreases over time throughout the era of incremental change. Findings imply a pattern of contraction and expansion in the era of incremental change that extends previous work on the technological product life cycles and helps to characterize the era of incremental change in a novel way. 相似文献
993.
Electronic word-of-mouth (eWOM) has been identified as a key factor affecting online sales. However, the factors leading to eWOM in the open-market context are not fully understood. Since many Internet vendors have adopted the open-market business model, it is essential to understand the factors for eWOM leading to the success of open-market business. This study investigates factors affecting eWOM in the open-market context based on a sequential combination of qualitative and quantitative research methods. The exploratory findings in the qualitative study form the basis for the quantitative study survey research. The findings from this mixed methods study indicate the significance of three new factors (information-sharing desire, self-presentation desire, and open-market reward) and two established factors (open-market satisfaction and open-market loyalty) affecting eWOM directly and indirectly. This study makes a useful contribution to the broader literature on eWOM. These findings also inform open-market providers as to how to promote and manage eWOM for online business success. 相似文献
994.
Yong Jin Kim Jong Man Lee Chulmo Koo Kichan Nam 《International Journal of Information Management》2013
Recent studies on IT outsourcing have examined the effect of contract specification and relationship strength on IT outsourcing performance in a separate manner. Previous studies, however, ignored the importance of the governance effectiveness that bonds contractual control and relationship strength together to deliver expected outcomes in IT outsourcing exchange. In this paper, we propose a model of IT outsourcing management where governance effectiveness mediates the effect of both contractual control and relationship strength on IT outsourcing performance. We collected data from 143 client companies of IT outsourcing and analyzed it using the PLS method. Our findings show that both contract specification and relationship strength significantly influence governance effectiveness, although contract specification carries the more effect on governance effectiveness than relationship strength does. The governance effectiveness in turn mediates the effect of contract specification and relationship strength on three sub-dimensions of outsourcing performance: cost efficiency, performance improvement, and overall satisfaction. The results and implications are further discussed. 相似文献
995.
Hsiao-Ping Chen Chia-Chun Tsai Hung-Meng Lee Shau-Chun Wang Hsueh-Chia Chang 《Biomicrofluidics》2013,7(4)
The authors exposed a non-equilibrium dynamic counterion and coion analyte concentration to an AC electric field to selectively concentrate peptides at the poles of a cation-selective granule. The counterion polarization results from the focusing of the electric field show a discontinuous drop in the intra-granule counterion electromigration flux at the pole. The coion concentration polarization is due to the combined external convective and electromigration fluxes toward the pole that neutralize the accumulating counterions. Because the electromigration mobility of the peptide anion analyte depends on the pH, the authors determined a 20 000-fold high concentration factor for a near-neutral pH of 6.0 to 7.7. Because the peptide is protonated at the acidic pole and its absolute charge ranges from −0.3 to −1.9, the concentration factor scales exponentially with the absolute charge, thus allowing extremely selective concentrations of various peptides, which is demonstrated by fluorescein isothiocyanate tagged angiotensin I (pI ∼ 5.8) and Texas red tagged avidin (pI ∼ 10.5). This dynamic concentration effect can substantially enhance the sensitivity of bio-assays. 相似文献
996.
Droplet-based microfluidic systems enable a variety of biomedical applications from point-of-care diagnostics with third world implications, to targeted therapeutics alongside medical ultrasound, to molecular screening and genetic testing. Though these systems maintain the key advantage of precise control of the size and composition of the droplet as compared to conventional methods of production, the low rates at which droplets are produced limits translation beyond the laboratory setting. As well, previous attempts to scale up shear-based microfluidic systems focused on increasing the volumetric throughput and formed large droplets, negating many practical applications of emulsions such as site-specific therapeutics. We present the operation of a parallel module with eight flow-focusing orifices in the dripping regime of droplet formation for the generation of uniform fine droplets at rates in the hundreds of kilohertz. Elevating the capillary number to access dripping, generation of monodisperse droplets of liquid perfluoropentane in the parallel module exceeded 3.69 × 105 droplets per second, or 1.33 × 109 droplets per hour, at a mean diameter of 9.8 μm. Our microfluidic method offers a novel means to amass uniform fine droplets in practical amounts, for instance, to satisfy clinical needs, with the potential for modification to form massive amounts of more complex droplets. 相似文献
997.
Anthony D. Mahon Andrea D. Marjerrison Jonah D. Lee Megan E. Woodruff Lauren E. Hanna 《Research quarterly for exercise and sport》2013,84(4):466-471
In this study, we compared measured maximal heart rate (HRmax) to two different HRmax prediction equations [220 — age and 208 — 0.7(age)] in 52 children ages 7-17 years. We determined the relationship of chronological age, maturational age, and resting HR to measured HRmax and assessed seated resting HR and HRmax during a graded exercise test. Maturational age was calculated as the maturity offset in years from the estimated age at peak height velocity. Measured HRmax was 201 ± 10 bpm, whereas predicted HRmax ranged from 199 to 208 bpm. Measured HRmax and the predicted value from the 208 — 0.7(age) prediction were similar but lower (p < .05) than the 220 — age prediction. Absolute differences between measured and predicted HRmax were 8 ± 5 and 10 ± 8 bpm for the 208 — 0.7 (age) and 220 — age equations, respectively, and were greater than zero (p < .05). Regression equations using resting HR and maturity offset or chronological age significantly predicted HRmax, although the R2 < .30 and the standard error of estimation (8.2-8.5) limits the accuracy. The 208 — 0.7(age) equation can closely predict mean HRmax in children, but individual variation is still apparent. 相似文献
998.
Mu-Tsung Chen Wen-Chih Lee Shih-Chang Chen Chiu-Chou Chen Chung-Yu Chen Shin-Da Lee 《Research quarterly for exercise and sport》2013,84(4):472-477
In the present study, we investigated the effect of a long-term mountain expedition on glucose tolerance and insulin action. Twelve registered mountaineers ages 31 years (SD = 1.1) participated in a 25-day expedition at a 2,200-3,800-m altitude with an average duration of 8 hr per day. Arterial oxygen saturation (SaO2) was substantially reduced during hiking. Glucose tolerance and insulin responses were measured prior to and twice during the expedition period. Maximal oxygen consumption increased from 43.0 ± 2.7 to 49.1 ± 2.2 mL/kg/min. Percentage of body fat decreased from 19.4 ± 6.8% to 16.9 ± 5.9%. The area under the curves for insulin and glucose during the oral glucose tolerance test were also reduced in Days 3 and 25. The present study demonstrated that altitude hiking activity is an effective lifestyle intervention to improve insulin action. 相似文献
999.
We investigated the culture of a responsibility-based physical activity program called Project Effort as well as the school culture of its participants. Five children who had at least one full semester of participation in the program participated in the study. We collected data from participants' individual interviews and observations of their involvement at school and in Project Effort. Findings revealed a distinct incongruence between the participants' perceptions of the atmosphere of the after-school program and school. Although explicitly similar values were emphasized between Project Effort and school, participants suggested these values were distorted between the two settings. For example, the empowerment values in Project Effort (e.g., respect, responsibility) were perceived as a discipline approach in the school setting. Participants' perceptions of cultural differences functioned as a barrier to the transfer of program values to the school context. 相似文献
1000.
Abstract In this study, we examined thermoregulatory responses to ingestion of separate aliquots of drinks at different temperatures during low-intensity exercise in conditions of moderate heat stress. Eight men cycled at 50% (s = 3) of their peak oxygen uptake ([Vdot]O2peak) for 90 min (dry bulb temperature: 25.3°C, s = 0.5; relative humidity: 60%, s = 5). Four 400-ml aliquots of flavoured water at 10°C (cold), 37°C (warm) or 50°C (hot) were ingested after 30, 45, 60, and 75 min of exercise. Immediately after the 90 min of exercise, participants cycled at 95%[Vdot]O2peak to exhaustion to assess exercise capacity. There were no differences between trials in rectal temperature at the end of the 90 min of exercise (cold: 38.11°C, s = 0.30; warm: 38.10°C, s = 0.33; hot: 38.21°C, s = 0.30; P = 0.765). Mean skin temperature between 30 and 90 min tended to be influenced by drink temperature (cold: 34.49°C, s = 0.64; warm: 34.53°C, s = 0.69; hot: 34.71°C, s = 0.48; P = 0.091). Mean heart rate from 30 to 90 min was higher in the hot trial (129 beats · min?1, s = 7; P < 0.05) than on the cold (124 beats · min?1, s = 9) and warm trials (126 beats · min?1, s = 8). Ratings of thermal sensation were higher on the hot trial than on the cold trial at 35 and 50 min (P < 0.05). Exercise capacity was similar between trials (P = 0.963). The heat load and debt induced by periodic drinking resulted in similar body temperatures during low-intensity exercise in conditions of moderate heat stress due to appropriate thermoregulatory reflexes. 相似文献