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关键词： 微动   合成距离像   步进频率信号   多普勒效应   离散傅里叶变换   范数  

摘要： 首先给出了微动目标合成宽带信号回波的一般模型,利用矩阵理论和离散傅里叶变换理论分析了微动目标合成距离像的一般数学原理和多普勒效应,证明了传统的最大二次相位误差准则不能精确地表征运动对距离像的影响,提出了新的距离像畸变度量指标,并给出了关于新准则的几个有用的结论,对步进频率信号进行了具体分析,最后给出了仿真计算,证明了理论分析的结论.

关键词： 岩土力学   研讨会   中国力学学会   解析方法   数值分析   数学分析  

关键词： 教育技术   数学   数学分析   黄金分割  

摘要： 本文以理论与实践的双重视角,深入阐述了教育技术与数学教学的内在关系,并在此基础上指出,教育技术是提高数学教育质量和培养学生思维能力的重要手段,同时教育技术的规范与完善也不能脱离数学理论及其创造性应用。因而,要想从根本上提高教育技术水平,首要的是提高数学智能。

关键词： reaction-diffusion systems   singular limit   Stefan problems  

摘要： We investigate a reaction-diffusion system for a parabolic equation coupled with an ordinary differential equation on an unbounded space domain. This system arises as a model for host tissue degradation by bacteria and involves a parameter describing the degradation rate that is typically very large. We prove the existence and uniqueness of solutions to this system and the convergence to a Stefan-like free boundary problem as the degradation rate tends to infinity. (c) 2006 Elsevier Ltd. All rights reserved.

关键词： complex fluids   multiscale models   well-posedness   numerical analysis   Doi-Onsager equation   micro-macro models  

摘要： The state of the art of the mathematical and numerical analysis of multi-scale models of complex fluids is reviewed. Issues addressed include well-posedness of the models, convergence analysis of the numerical methods, and the structure of stationary solutions of the Doi-Onsager equation.

关键词： bedding   mathematical evaluation   rebreathing   respiratory simulation   sudden infant death  

摘要： Rebreathing is a model for the relationship between a prone sleeping position and sudden infant death syndrome. This study used a mechanical simulation model to establish the relationship between types of bedding and rebreathing potential for an infant placed prone (face down) at different postnatal ages. The infant mannequin was connected to a respirator set to deliver physiologically appropriate combinations of tidal volume (VT) and respiratory rates (RR) across a range of postnatal ages (0-18 months). Before measurements were made, CO2 flow was regulated to 5 +/- 0.1% of end-tidal PCO2 (EtCO2). After the model was placed in a prone position, any increase in the fractional concentration of inspired CO2 (FiCO(2)) was measured. FiCO(2) increased immediately and rapidly, and reached a maximum value within a few minutes. The maximum FiCO(2) ranged from under 2% to over 10%, depending on the bedding. FiCO(2) was also affected by VT and RR. This model is not applicable to actual infants because of the large tissue stores Of CO2 in infants;however, it is useful for evaluation of gas diffusibility of bedding and will simplify the investigation of sleeping environments when a baby is found dead with its face covered by soft bedding. In general, the higher the FiCO(2), the greater the rebreathing potential. Theoretically, considering the paucity of body stores Of O-2, changes in FiO(2) would be affected not by changes in FiCO(2), but by CO2 production and gas movement around the infant's face. The rapid decrease of FiO(2) is approximated at the inverse of the FiCO(2) timecourse, suggesting the significance of not only CO2 accumulation but also O-2 deprivation in the potential space around the baby's face. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

关键词： 迁移   数学分析   正迁移   负迁多  

摘要： 按照认知心理学的迁移理论,在数学分析教学中可以根据相关知识体系的特点促进知识学习的正迁移,同时采取合理的教学策略把负迁移的影响降至最低,从而达到提高教学效果的目的.

关键词： trading systems   money management   entropy maximization   convex optimization   information rate  

摘要： Investment systems are studied using a framework that emphasize their profiles (the cumulative probability distribution on all the possible percentage gains of trades) and their log return functions (the expected average return per trade in logarithmic scale as a function of the investment size in terms of the percentage of the available capital). The efficiency index for an investment system, defined as the maximum of the log return function, is proposed as a measure to compare investment systems for their intrinsic merit. This efficiency index can be viewed as a generalization of Shannon's information rate for a communication channel. Applications are illustrated. (c) 2006 Elsevier Inc. All rights reserved.

关键词： 函数   连续   思想方法   数学素养  

摘要： 师范专科数学分析教学要让学生掌握数学分析的宏观、微观的知识体系;掌握数学思想方法,如函数的思想方法、极限的思想方法、连续的思想方法、化归的思想方法等;还要培养学生的数学素养。以利于学生数学分析的学习及日后的发展。

关键词： 数学分析   概念   能力   逆向思维   发散思维  

摘要： 文章着重探讨了类比推理方法;采用不同方式表述同一概念方法;逆向分析制造反例方法;运用几何模型和图表表述概念方法等在分析教学中的应用,强调概念教学要以培养学生自我学习能力为宗旨.