轴向流中平行简支弹性薄板的大挠度流固耦合的数值模拟

分析研究了轴向流中简支弹性薄板大挠度流固耦合系统的振动响应和流场特性.板结构动力学方程采用基于位移的有限元法离散;流场采用二维不可压缩粘性流体N-S方程,并用有限体积法离散;在此基础上结合动网格控制技术,建立模拟双向流固耦合作用下轴向流中简支弹性薄板的二维数值模型.利用该数值模型得到了单块简支板随流速变化流致振动特性,研究了结构大挠度的振动稳定性,分别得到了Pitchfork分岔曲线和非线性系统结构的Hopf分叉曲线.通过轴向流恒定流速下不同间距的平行两块简支弹性薄板流固耦合的数值模拟得到了的流致振动特性.     

一种用于室内定位的线性规划算法

针对基于ToA定位中存在的信标节点较少和发送时间不能提前预知的问题,提出了一种新的应用于无线传感网络室内定位的线性规划算法.通过考虑测量值的最小平均绝对值误差,利用线性逼近方法,将一个复杂的、非凸的室内定位问题转换为一个简单的线性规划问题,并用迭代求精的方法求出最优解.仿真结果表明,提出算法计算复杂度低,收敛速度快,可以快速地求出未知节点的坐标;通过和已有的定位算法相比,提出算法在信标节点较少的情况下,仍能保持很好的定位精度,利用较少的节点资源达到比已有算法更好的定位性能.     

Research on droplet formation and dripping behavior during the electroslag remelting process

A better understanding of droplet formation and dripping behavior would be useful in the efficient removal of impurity elements and nonmetallic inclusions from liquid metals. In the present work, we developed a transparent experimental apparatus to study the mechanisms of droplet formation and the effects of filling ratio on droplet behavior during the electroslag remelting (ESR) process. A high-speed camera was used to clearly observe, at small time scales, the droplet formation and dripping phenomenon at the slag/metal interface during a stable ESR process. The results illustrate that a two-stage process for droplet formation and dripping occurs during the ESR process and that the droplet diameter exhibits a parabolic distribution with increasing filling ratio because of the different shape and thermal state of the electrode tip. This work also confirms that a relatively large filling ratio reduces electricity consumption and improves ingot quality.     

厚层状高压低渗透低饱和油藏压裂效果的预测

本文从马西油田的实际出发,通过对该油田板二油组地质特征、压裂工艺的数理统计、分析、研究,运用微机数据处理,建立了高压、厚层状、低渗透、低饱和油藏,压裂平均日产、有效天数及累计增产油量的数学模型,对压裂增产效果的预测,有重要的指导作用。     

旋转盘的可靠性分析

本文分析在几何形状为随机量时旋转盆的力学特性,用二阶摄动方法导出旋转盘的随机应力场和可靠度的计算公式,简单算例分析讨论了几何尺寸对可靠性的影晌现律。算例结果与Monte Carlo模拟结果进行比较.表明本文提出的方法是有效的,理论是正确的。     

用基因算法实现切削参数的现场实时优化

为了使金属切削加工中,切削参数能实现实时优化保证产品质量和设备效率,提出采用基因算法。它是基于生物进化理论的优化算法,对问题进行全局的、并行的启发式探索优化,因而可以防止收敛于局部最优解,且搜索效率优于其它方法;适用于具有多参数、多约束条件和多目标的切削参数优化。基因算法结合现场实际工况的反馈信息实现了实时优化,在任一不同的生产条件下均能达到最优值。     

主理想整环上的一类矩阵方程

讨论了预加范畴中的态射方程ａｘβ＋σｙτ＝γ,给出了其有解的充要条件和通解公式,并且,对主理想整环上的矩阵方程ＡＸＢ＋ＣＹＤ＝Ｅ给出了相应的结论。     

CORBA与Web整合--CORBA Page

利用ＣＯＲＢＡ技术,能够将分布式对象和Ｗｅｂ技术进行整合ＣＯＲＢＡ提供了在异质平台上构造对程序开发人员透明的分布式环境。通过ＣＯＲＢＡ技术同Ｗｅｂ的整合,能够产生可移植性、可扩充性优于传统客户机／服务器模式的应用平台。     

健美选项课中学生终身体育观的培养

结合高校健美选项课的教学实践,就学生终身体育观的培养提出了看法。     

SCTE: RCS prediction system for complex target and interaction with environment

A RCS prediction system named SCTE (Scattering from Complex Target and Environment) for calculating high-frequency electromagnetic scattering from complex target within complex environment is presented. The scattering body is described by Computer-Aided-Design (CAD) representations in which the complex body is modeled as NURBS (Non-Uniform Rational B-spline) surfaces. The complex environment (rough surface of sea or ground) is also carefully considered by using fractal function. Scattering fields are calculated by using physical optics and the equivalent currents methods. There is a good agreement between the present results and that from measurements which demonstrates the accuracy of this system. Foundation item: Supported by the National Natural Science Foundation of China Biography: CAO Qin-feng (1972-) male, Ph.D. candidate.