能量平衡法静电驱动柔性振膜微泵特性分析

从能量平衡的角度建立了静电驱动柔性振膜微泵的平衡方程,基于对压缩过程中振膜动能的考虑,改进了最小能量法压缩模型,结合均匀压力载荷下圆薄膜大挠度形变理论对静电驱动柔性振膜微泵进行理论分析.对振膜与腔体壁面贴合的压缩过程中各能量相互转化的关系进行分析,并与最小能量法模型进行了对比.结果表明,能量平衡法考虑了薄膜振动过程中的动能,故薄膜与腔体具有更大的贴合面积,且以薄膜与腔体完全贴合时作为零应力参考状态降低压缩过程中的薄膜形变势能,计算得到的静电微泵的压缩效率更高,在驱动电压为300 V时,改进的双腔模型中振膜贴合半径为4.06 mm,所得最大压升为87.08 kPa.基于改进的模型,对双腔微泵压升的影响因素进行讨论,发现降低柔性薄膜厚度会使输出压力有所上升,并且减小腔体表面介电层厚度、减小腔体深度与半径可以有助于提高微泵的压升.     

An improvement of cluster variation method entropy functional for bcc alloys

The entropy functional in the tetrahedron approximation of the cluster variation method (CVM) for the body-centered cubic structure has been modified to yield accurate consolute temperature for a phase separating system. The improvement is achieved by a change in the multiplicity of the basic tetrahedron cluster and approximately accounts for truncation errors in the entropy functional of CVM owing to finite size of the basic cluster. We demonstrate that the phase diagram, thermodynamic properties and short range order parameters show improved agreement with more accurate results, without involving additional computational burden. Hence, the modified entropy functional could be used as a standard for CVM.     

Necessary and sufficient convergence conditions of the instrumental variable method for identification

The consistency of the instrumental variable method is considered for a system driven by independent identically distributed input signals with zero mean. Necessary and sufficient conditions for convergence are developed with respect to the given model structure. The sufficient and necessary conditions are established for cases with and without data prefiltering. In this paper we extend on existing results such that the requirements on the degree of the instrumental variables can be relaxed. Numerical examples supporting the theoretical results are provided.     

Symmetric and symplectic exponentially fitted Runge–Kutta–Nyström methods for Hamiltonian problems

The construction of symmetric and symplectic exponentially fitted modified Runge–Kutta–Nyström (SSEFRKN) methods is considered. Based on the symmetry, symplecticity, and exponentially fitted conditions, new explicit modified RKN integrators with FSAL property are obtained. The new integrators integrate exactly differential systems whose solutions can be expressed as linear combinations of functions from the set { exp(± iωt)}, ω > 0, i² = −1, or equivalently from the set { cos(ωt), sin(ωt)}. The phase properties of the new integrators are examined and their periodicity regions are obtained. Numerical experiments are accompanied to show the high efficiency and competence of the new SSEFRKN methods compared with some highly efficient nonsymmetric symplecti EFRKN methods in the literature.     

严寒环境下排水管线施工方法

严寒环境下排水管道施工问题一直是困扰施工单位和建设单位的一大难题。作者在长期的施工和设计工作中,总结出以下严寒环境下排水管线施工方法,即管道的防腐、焊接、检查井井盖等重点施工项目集中保护处理;管沟开挖、回填及管道闭水试验快速处理;检查井及检查井进出水管制作及连接特殊处理的方法,从而保证整个工程施工质量合格,并且节省工程费用,保障施工单位和建设单位的经济利益不受损失。     

一类新复合形法及其在临界滑动面搜索中的应用

针对广泛采用的基本复合形法存在着搜索不完全、映射系数取值不灵活、复形多样性保持差等缺陷,提出了相应的改进措施,如动态全域映射收缩算子以及最大冗余点映射准则,形成了一类新型的复合形法。在确定冗余点时综合考虑了距离空间和目标函数值两方面的信息。通过对某复杂土坡的最危险滑动面的搜索表明,新型复合形法的寻优成功率比基本复合形法大大提高。     

交流电机绕组分布系数推导方法的研究

对交流电机绕组分布系数推导的代数法进行了详尽描述,并对代数法与几何法进行了比较。     

Windows CE下基于SPI总线的双机通信技术

智能分析仪器要求在Windows CE系统下能够通过SPI总线实现副板与主板、主板与主板之间的数据传输。首先介绍了SPI双机通信的机理,其次分析了Windows CE下的中断处理机制的流程,最后从内核态的中断服务程序、驱动层的中断服务线程、流接口函数、驱动加载等方面实现了Windows CE下SPI双机通信的驱动程序。实验表明,两个智能分析仪器的主板之间能够可靠、稳定地传输数据。     

一种基于软阈值方法的改进A1/A2极化干涉分类算法

在分析了极化干涉技术的发展现状和发展趋势的基础上,从极化干涉的特殊性入手,分析了干涉相干系数在极化干涉分类中的作用,并且系统分析了基于相干最优优化后的相干系数进行极化干涉分类过程的原理,总结了现有极化干涉分类算法在阈值选择方面存在的不足,阐述了硬阈值方法和软阈值方法的基本原理和它们之间的区别,最后提出基于软阈值方法的改进A1/A2非监督极化干涉分类算法,解决了极化干涉分类现有的分类空间中的阈值问题。实验表明这种方法能够得到更好的分类结果,做出了改进。     

联合采用多代理和禁忌方法的系统恢复策略

将多代理技术MAT的分布式信息处理和禁忌方法TSM有机结合,形成了一种新型分布式电力系统恢复模型。模型由多结点智能代理GIAGs(crunode intelligent agents)和一个智能控制代理ICAG(intelligent control agent)组成,通过多个CIAGs间交互协商处理及ICAG的基于TSM的协同求解,能够实现快速恢复决策。仿真结果表明,该模型不仅能够快速获得恢复优化策略,而且对网络拓扑结构变化具有较强的适应性。