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181.
182.
《Expert systems with applications》2007,32(1):38-46
This paper explores the quantitative relationship between knowledge sharing and performance, with contextual factors in consideration. First, we argue that both knowledge sharing and its contextual factors should be associated with performance. Then, we analyze the multi-dimensional characteristics of knowledge sharing and propose six measures for it. Next, we model the relationship between knowledge sharing and performance, integrating various contingent factors with the model framework, some of which have significant influences on the relationship between knowledge sharing and performance. After that, we propose four alternative models and corresponding propositions for knowledge sharing-contingent variables relationship, and present a quantitative formulation of the relationship between knowledge sharing and performance. Finally, we conduct a survey of 249 organizations in Xi’an, China, and show the empirical results. Our propositions about the knowledge sharing-performance relationship and contingent factors are supported by the survey. The empirical results suggest that managers have to pay attention to some contingent factors while they commit to knowledge sharing. This study adds to the understanding of the effects of knowledge sharing on performance, and gives implications to the practice of knowledge sharing. 相似文献
183.
《钢铁研究学报(英文版)》2006
The paper refers to a novel permanent magnet motor with composite-rotor, to solve the difficulties of extend speed by “flux weakening”. The rotor is composed of two rotor segments: one is made of AINiCo magnet and the other of NdFeB. Relying on high coercive force and high remnant magnetic flux density quality of NdFeB, permanent magnet motor could get enough air gap magnetic fields. On the other way, by making using of low coercive force characteristics of AINiCo magnet, die permanent motor could be changed the orientation and strength of magnetization when applying a pulse of magnetizing (demagnetizing) current, thus magnetic flux in air gap could be varied over wide range. To achieve the aim, the paper analyzes magnetization process of permanent magnet and transient magnetic circuit in the motor, and then computes the distribution of air gap magnetic field in different magnetization by using finite element method. The numeral results show the validity of the scheme. 相似文献
184.
Oils in Jinghu sag are abundant with high content of polar compounds and have a low ratio of saturate to aromatic hydrocarbons and a high ratio of resin to asphaltene. The gross composition of oils in the Jinghu sag suggests typical immature to low mature characteristics. Some compounds with low thermal stability were identified. Light hydrocarbons, a carbon preference index, an odd even index, n-alkane and hopane maturity parameters show mature features and little differences in the maturity level among oils. Sterane isomerization parameters indicate an immature to low mature status of oil. Transfer of the sedimentary center during sedimentation has led to different thermal histories among subsags and thus generated oils with different maturities. On the basis of source analyses, four migration and accumulation patterns with different maturity can be classified. Combined with available information on mergers of source, reservoir and long distance oil lateral migration, mixing conditions were present in the Jinghu sag. Experimental results indicate that maturity variations are caused by mixtures of hydrocarbons with different maturity. 相似文献
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187.
真空微电子三极管是近年来兴起与发展的真空微电子学中的一类重要器件。本文从真空微三极管的工作特性出发,分析了这类器件中所需考虑的几何参数和工作特性的关系,并给出了一些理论和实验公式,为今后的设计提供一些参考。 相似文献
188.
Compressive and tribological properties of Al2O3 fibre and hexagonal BN particle hybrid reinforced Al-Si alloys 总被引:6,自引:0,他引:6
Al2O3 fibre-hexagonal BN particle hybrid reinforced aluminium-silicon alloys were fabricated by centrifugal force infiltration route. Hardness test and ultimate compressive test results are reported. The wear and friction properties of hybrid MMCs was investigated by means of a block-on-ring (bearing steel) type wear rig in a dry sliding condition. It is shown that the hardness and ultimate compressive strength of hybrid MMCs was evidently decreased with the addition of hexagonal BN particles, however, the wear rate and coefficient of friction of hybrid MMCs was improved simultaneously with increase of BN particle volume fraction, especially for the higher applied loads in the test. 相似文献
189.
《International Journal of Heat and Mass Transfer》2007,50(23-24):4581-4599
An infrared imaging system is used to measure detailed distributions of local heat transfer coefficient from rectangular channels with two opposite wide walls roughened by 45° staggered ribs of twenty test cases. Nusselt number (Nu) contours over the ribbed surfaces are presented for five sets of channels with an identical rib-floor configuration, but different channel-heights where the complex Nu distributions without bleed and then with bleeds from the scanned rib-floor or from the ribbed wall opposite to the scanned rib-floor or from the smooth sidewall are analyzed to examine the synergetic effects of variable channel-heights and different bleed conditions on heat transfer. Spatially averaged heat transfer results for the entire set of test channels are generated with the thermal performance factors compared to establish the heat transfer correlations with applications to the design of coolant channels in a gas turbine blade. 相似文献
190.
《Mathematics and computers in simulation》2006,71(2):121-130
An information criterion-based model selection method is proposed for monitoring unit root and multiple structural changes. In this method, a battery of possible models is considered by changing the integration order (I(0) or I(1)) and the combinations of change points. Next, the best model is selected from among alternative models via a modified Bayesian information criterion (BIC). Accordingly, on the basis of the selected model, the process that generates the observed time series is determined. The BIC is modified in order to adjust the frequency count of incorrectly selecting stationary models via the conventional BIC. The simulation results of monitoring unit root and structural change suggest that the proposed method outperforms the conventional hypothesis testing method in terms of detection accuracy and detection speed. Furthermore, the empirical results suggest that the proposed method exhibits better performances with regard to detection stability and forecastability. 相似文献