线性流形上对称自正交相似矩阵最佳逼近

讨论了线性流形上对称自正交相似矩阵的最小二乘解,得到了解的一般表达式,对于任意给定的矩阵A*,在最小二乘解集中得到了的A的最佳逼近解.     

由常规故障和临界人为错误引起系统故障的可修复系统动态解的最优控制

研究了由两个运行部件和一个储备部件并且具有常规故障和临界人为错误的随机模型,故障系统的修复时间是任意分布的.先把系统方程的解转化为Volterra 积分方程的形式,证明了系统方程中正解的存在唯一性,再以泛数指标泛函作为衡量系统可控性的标准,研究该系统的最优控制问题.     

拟次Hermite矩阵方程的解

A,M,x为n阶矩阵,M可逆,当A为由M确定的拟次Hermite矩阵时,讨论复数域上矩阵方程X AX=A的求解问题,给出了解的表达式,其中X＝M－1XsM,为X的共轭次转置矩阵。     

固体火箭发动机低空羽流场的相似研究

本文针对固体火箭发动机低空羽流场的数据外推问题进行研究。应用相似方法分析发动机低空羽流场模型,整理相似准则及相似条件。简化相似模型,根据工程计算半经验方法,拟和低空羽流温度场的计算公式,计算结果与工程计算数据基本吻合,验证了相似方法的可行性。     

Bessel方程的边值问题解的相似结构

将微分方程的边值问题的解式整理成具有相似结构的形式,使其更有利于进一步地分析解的内在规律;并提出了解式的相似性,与相对应的数和形的相似性统一起来,完善了数学上的三位一体和谐统一的理论.     

SYNTHESIS OF POLYBINAPHTHYLS INCORPORATING CHIRAL (R)-1,1′-BI-2,2′-NAPHTHOL ENTITIES WITHp-DIVINYLBENZENE BY Pd-CATALYZED HECK REACTION

Polymer (Ⅰ) and polymer (Ⅱ) were obtained by the polymerization of (R)-6,6′-dibromo-2,2′-binaphtho-20-crown-6(M-1) and (R)-6,6′-dibromo-2,2′-di(methoxyethoxymethyloxy)-1,1′-binaphthyl (M-2) with p-divinylbenzene under Pdcatalyzed Heck reaction. The UV, fluorescence and CD spectra of polymer (Ⅰ) and (Ⅱ) are similar due to the same linkers present in their polymer chain. Polymers (Ⅰ) and (Ⅱ) can emit strong blue fluorescence and are expected to have potential applications in polarized blue-light emitting sensors. The chiral conjugated polymers (Ⅰ) and (Ⅱ) exhibit a strong Cotton effect in their circular dichroism (CD) spectra, indicating a high rigidity of polymer backbone.     

A facile synthesis of phthalein indicator dyes

The use of methanesulfonic acid offers a novel and highly efficient method for the synthesis of phthalein indicator dyes in excellent yields on an industrial scale.     

不同管状和材料对结构能量吸收性能的影响

提出了评价和比较各类管件结构的能量吸收性能的评估指标体系,具体指标为：有效行程比(ESR)、结构承载能力(NLC)、单位重量的能量吸收能力(SEA)、吸能有效率(EEA)和载荷波动度(ULC)。为了分析截面和材料对管件能量吸收能力的影响,比较了铝合金和低碳钢2种材料的圆管和方管的能量吸收性能。结果表明：在相同密实度下,圆管的能量吸收能力要优于方管,且在同一截面的管件中,铝合金管件的能量吸收能力和载荷波动程度要优于低碳钢管件。     

含铝炸药水中爆炸冲击波相似律适应性探索

针对含铝炸药非理想性显著的特点,探索其水中爆炸后远场冲击波相似律的适用性。实验在8 kg当量TNT的爆炸水池中进行,在距离爆心不同位置处测量了冲击波压力剖面曲线,得到了峰值压力和压力衰减时间,结合量纲分析方法和含铝炸药的特点,对冲击波相似律适用性问题进行了探讨。实验结果表明,对于含铝炸药来说,存在着峰值压力相似而时间常数不太相似的特点,这与铝粉的二次反应放能有关。     

Spatial statistical analysis of the effects of urban form indicators on road-traffic noise exposure of a city in South Korea

The purpose of this study is to present a statistical model which can predict the noise level of road-traffic in urban area. A spatial statistical model which can take into account spatial dependency on geographically neighboring areas is constructed from a noise map of a city in South Korea. A system of 250 m × 250 m grid cells is placed on the city of Cheongju, South Korea, and the noise level and urban form indicators are averaged over each cell. The population-weighted mean of the noise level is subsequently regressed on the average urban form by adopting the spatial autoregressive model (SAR) and the spatial error model (SEM), as well as an ordinary least squares (OLS) model. Direct and indirect impacts are analyzed for a valid interpretation of the spatial statistical models. Factors such as GSI, FSI, traffic volume, traffic speed, road area density, and the fraction of industrial area turn out to have significant impacts on the noise level.