不可压缩N-S方程的稳定分步算法及耦合离散

在有限增量微积分(finite increment calculus, FIC)的理论框架下，通过引入一个附加变量，发展了压力稳定型分步算法，有效改善了经典 分步算法的压力稳定性，同时还避免了标准FIC方法中存在的空间高阶导数的计算. 为保证 数值方法同时具有较快的计算速度和较好的健壮性，发展了有限元与无网格的耦合空间离散 方法. 该方案可在网格发生扭曲的区域采用无网格法空间离散以保证求解的精度和稳定性， 而在网格质量较好的区域以及本质边界上保留使用有限元法空间离散以提高计算效率和便于 施加本质边界条件. 方腔流考题的数值模拟结果突出地显示了所发展的压力稳定型分步算 法比经典分步算法具有更好的压力稳定性，能够有效消除速度-压力插值空间违反LBB条件而 导致的压力场的虚假数值振荡. 平面Poisseuille流动和一个典型型腔充填过程的数值模拟 结果, 表明了发展的耦合离散方案相对于单一的有限元法和单一的无网格法在综合考虑计 算效率和算法健壮性方面的突出优点.     

删失分位数回归模型基于扩展兴趣信息准则的平均估计

本文结合分位数回归技术,基于删失回归模型,把Claeskens和Hjort的传统兴趣信息准侧(focused information criterion,FIC)扩展到兴趣向量的情形,提出扩展的兴趣信息准则(extended focused information criterion,E-FIC),有效解决了同时针对多个兴趣参数的平均估计问题,并且对删失响应变量的不同水平分位数进行建模,以全面反映响应变量分布特征,有效克服异常值和厚尾模型误差的影响.基于扩展的兴趣信息准则给出参数的平均估计方法,证明估计的渐近性质.通过Monte Carlo随机模拟试验比较所提估计方法和最小二乘方法在有限样本量下的表现,用所提方法对原发性胆汁性肝硬化数据集进行数据分析.     

非交换环的拟零因子图

In this paper, a new class of rings, called FIC rings, is introduced for studying quasi-zero-divisor graphs of rings. Let R be a ring. The quasi-zero-divisor graph of R, denoted by Γ_*(R), is a directed graph defined on its nonzero quasi-zero-divisors, where there is an arc from a vertex x to another vertex y if and only if x Ry = 0. We show that the following three conditions on an FIC ring R are equivalent:(1) χ(R) is finite;(2) ω(R) is finite;(3)Nil_*R is finite where Nil_*R equals the finite intersection of prime ideals. Furthermore, we also completely determine the connectedness, the diameter and the girth of Γ_*(R).     

基于嵌入式Linux的网络摄像机设计

提出了一种基于32位嵌入式操作系统的网络摄像机设计思路，并从硬件结构、软件框架方面介绍系统的具体实现方法．采用台湾智源公司的FIC8120作为系统主控芯片，省去了设计专门音视频压缩编码模块，显著减少了系统复杂性．该软件平台采用可移植、裁减和实时多任务特性的Linux操作系统，可用于处理复杂的网络传输协议，具有良好的稳定性和可靠性．     

Volumetric properties of 1-iodoperfluorohexane+<Emphasis Type="Italic">n</Emphasis>-octane binary system at several temperatures

New densities are reported over the whole composition range for 1-iodoperfluorohexane+n-octane system at temperatures from 288.15 to 308.15 K at atmospheric pressure. These data have been used to compute the excess molar volumes, V _m ^E. Large positive V _m ^E values have been obtained over the entire range of composition, which increases when the temperature rises. The experimental data were used to calculate the isobaric thermal expansivity, and the quantities (∂V _m ^E/∂T)_p and (∂H _m ^E/∂p)_T. Furthermore, the results have been used to investigate the volumetric prediction ability of the equations of state Soave–Redlich–Kwong, Peng–Robinson, Patel–Teja and Soave–Redlich–Kwong with volume translation.