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排序方式: 共有1146条查询结果,搜索用时 15 毫秒
71.
Hong LiYang Wu Yunsheng GeJia Jiang Kai GaoPengyun Zhang Lingxiang WuShiyi Chen 《Applied Surface Science》2011,257(22):9371-9376
The purpose of this study was to determine the effect of the combination of hydroxyapatite (HA) and bioglass (BG) on polyethylene terephthalate (PET) artificial ligament graft osseointegration within the bone tunnel. The results of in vitro culturing of MC3T3-E1 mouse osteoblastic cells proved that this HA/BG composite coating can promote the cell compatibility of grafts. A rabbit extraarticular tendon-to-bone healing model was used to evaluate the effect of this composite coating on PET artificial ligaments in vivo. The final results demonstrated that HA/BG coating improved new bone formation at the graft-bone interface and increased the load-to-failure property of graft in bone tunnel compared to the control group at early time. The study has shown that HA/BG composite coating on the PET artificial ligament surface has a positive effect in the induction of artificial ligament osseointegration within the bone tunnel. 相似文献
72.
人工神经网络法用于高效毛细管电泳分离条件优化的研究 总被引:9,自引:1,他引:8
把人工神经网络(ANN)法应用于高效毛细管电泳(HPCE)分离条件的优化,给出了反向传播(BP)的ANN模型的具体算法。用正交试验法同时考察了缓冲溶液组成、浓度、pH值和有机添加剂浓度等实验因素对HPCE分离合成色素和防腐剂的影响,采用误差反向传播方法建立了有效的ANN预测模型,预测最佳分离条件,获得了满意的分离结果。 相似文献
73.
XU Yong WANG Binglin 《声学学报:英文版》1993,(3)
The author has made tests for an artificial head transfer system whichis modelled on a Chinese male on its main physical behaviour such as frequencyresponses,frequency response differences between the front and the rear inci-dences,as will as on its important hearing behaviour such as localization,theperception of distance and room dimensions.The results verify that this kind ofartificial head transfer system can be used as one of effective tools of acousticevaluation researches for halls. 相似文献
74.
A hybrid valuation methodology is proposed and tested for improving the efficiency of contingent claims pricing by combining Artificial Neural Networks (ANN) and conventional parametric option pricing techniques. With one application on financial derivatives and one on real options the methods superiority is demonstrated. The resulting efficiency is instrumental for real time applications.MSC code:
90-08
Acknowledgements: Both authors are thankful for partial financial support to the HERMES European Center of Excellence on Computational Finance and Economics of the University of Cyprus and a University of Cyprus grant for research in ANNs and Derivatives, and to the anonymous referees for their helpful comments and discussions. 相似文献
75.
76.
A. Chaudhury R. Khatirkar N.N. Viswanathan V. Singal A. Ingle S. Joshi I. Samajdar 《Journal of magnetism and magnetic materials》2007
Commercial supply, from several steel manufacturers, of low-silicon non-grain-oriented electrical steel was monitored over a span of several years. A total of 51 samples were selected—selected from many hundreds on the basis of large differences in magnetic properties, but absence of significant variations in chemistry (other than differences in silicon percentage). The selected samples were analyzed for crystallographic texture and for grain size. 相似文献
77.
78.
This paper addresses the theoretical analysis of a fully discrete scheme for the one-dimensional time-dependent Schrödinger equation on unbounded domain. We first reduce the original problem into an initial-boundary value problem in a bounded domain by introducing a transparent boundary condition, then fully discretize this reduced problem by applying Crank–Nicolson scheme in time and linear or quadratic finite element approximation in space. By a rigorous analysis, this scheme has been proved to be unconditionally stable and convergent, its convergence order has also be obtained. Finally, two numerical examples are performed to show the accuracy of the scheme. 相似文献
79.
C. Merlatti F.X. Perrin E. Aragon A. Margaillan 《Polymer Degradation and Stability》2008,93(5):896-903
Depth-profiling by Fourier transform infrared (FTIR) spectroscopy, dynamic mechanical analysis (DMA), microhardness and scanning electron microscopy (SEM) observations have been used to monitor degradation chemistries in two-package acrylic–urethane coatings when exposed to different exposure conditions. Three artificial and three natural weathering protocols (QUV, ASTM D5894, ISO20340, Pipady (south of France), Bandol (south of France) and Kure Beach (USA)) were selected for this study. The same chemical events were found to occur under all conditions, particularly under natural and artificial exposures. Both loss of the amide II band at 1520 cm−1 and carbonyl growth occurred but at relatively low rate owing to the presence of hindered-amine light stabilizers in the film. A less typical loss of urea biuret linkages also occurs during all exposures and results in a change in the balance between urethane and urea links across the depth of the film during weathering. The chemical degradation of the polymer matrix involves the formation of species that are readily ablated from the surface and results in loss of gloss, increase in hardness and a rougher topology. The dramatic loss of gloss observed after Pipady and Bandol exposures show that loss of gloss should not be systematically correlated to the advance in chemical degradation. 相似文献
80.
Markus Schinhaerl Gordon Smith Richard Stamp Rolf Rascher Lyndon Smith Elmar Pitschke Peter Sperber Andreas Geiss 《Applied Mathematical Modelling》2008
Computer-controlled polishing (CCP) is commonly used to finish high-quality surfaces, such as optical lenses. Based on magnetorheological finishing (MRF), a mathematical model to calculate the polishing tool characteristic (influence function) was developed and verified experimentally. The first part of this paper introduces the model to predict the size and shape of an influence function. The second part of this paper describes the calculation of the distribution of material removal within the size of an influence function. The model supersedes the current cumbersome procedure for determining an influence function and thus results in considerably improved and more economical manufacture. Furthermore, the model enables the quality of the final surface to be enhanced when polishing complex, for example aspherical or free-form, workpiece geometries and provides the first step in the application of time-variant influence functions. 相似文献