Stability Analysis Using the Minimum Function Analysis Approach

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一类新的极小谱任意符号模式

若给定任意一个$n$次首一实系数多项式$f(\lambda)$,都存在一个实矩阵$B\in Q(A)$, 使得$B$的特征多项式为$f(\lambda)$,则称$A$为谱任意符号模式. 如果一个谱任意符号模式的任意非零元被零取代后所得到的符号模式不是谱任意,那么这个谱任意符号模式称为极小谱任意符号模式.本文证明一类极小谱任意符号模式.     

汉英的姓氏差异及其文化根源

众所周知,中英文化的区别不仅体现在表面上,更表现为深层的人文心理差异。与发轫于两希文明的英国文化相比,中国文化自成体系,在本区属于优势文化,其传承的过程较为系统、单纯。此种文化的差异大到政治思想,经济体制和人文传统,小到姓氏文化的民族取向都有着具体细微的表现。文章试图从英国的姓氏文化和中国姓氏文化的主要特征入手寻找差异,研究其差异的深层文化因素,并从现实操作的角度来把握两种文化的人文心理差异,以期更好地实现中英之间的互解和交流。     

安全禁止标志识别率与标志特征关系研究

为提高安全标志有效性,需要对安全标志五维特征与标志识别率关系进行研究。选取50名安徽工程大学在校学生为试验对象,40个禁止安全标志为试验材料,研究安全标志的五维特征与标志识别率的关系,建立安全标志识别率与标志五维特征的多元线性回归方程模型。结果表明:标志的熟悉性对标志识别率影响最大,其后依次为简明性、具体性、语义相关性、明确性。此外,回归模型中,常数项为正值,说明仍有其他因素影响标志识别率,有待进一步研究发现。     

基于非均等排序集抽样的符号检验

为检验未知总体的中位数,提出基于非均等排序集抽样的符号检验.通过比较符号检验的Pitman效率,表明非均等排序集抽样效率高于排序集抽样和简单随机抽样. 考虑到非均等排序集样本独立但不同分布,提出与秩次有关的加权符号检验,具体给出使检验效率达到最大的权数,并证明出最优权数具有适应任意分布性. Pitman相对效率的计算结果表明,非均等排序集抽样下最优加权符号检验优于排序集抽样下最优加权符号检验. 最后,对阔叶松树的一组真实数据进行了实际应用.      

基于北斗定位导航系统的士兵状态监视与指挥控制系统

战场救护中,及时发现士兵伤情并迅速找到伤员是挽救伤员的重要条件,因此,对受伤士兵的定位与获取需救护伤员的准确个人信息对于救护的有效性具有非常重要的意义。基于北斗卫星的定位导航系统设计战场士兵信息采集与指挥控制系统,利用我国自主研发的北斗卫星导航定位通信系统对战场士兵进行定位,通过由基于蓝牙的士兵状态监视终端对士兵生理状态参数进行连续监测,当发现士兵伤情时实时由通信终端向指挥控制中心传递伤员个人信息和生理状态参数,指挥中心接收伤员数据后,通过GIS系统、根据地形等信息可实时规划救援路线和救援方案,以实现对伤员的及时救治。分析了北斗卫星导航系统的功能与特点,介绍了士兵信息采集与指挥控制系统的组成及功能,详细阐述了士兵信息采集终端的设计、生命体征信息监测方法、指挥控制系统的组成与功能以及地理信息系统(GIS)设计。     

幂零--中心化方法

An nxn complex sign pattern(ray pattern) S is said to be spectrally arbitrary if for every monic nth degree polynomial f(λ) with coefficients from C,there is a complex matrix in the complex sign pattern class(ray pattern class) of S such that its characteristic polynomial is f(λ).We derive the Nilpotent-Centralizer methods for spectrally arbitrary complex sign patterns and ray patterns,respectively.We find that the Nilpotent-Centralizer methods for three kinds of patterns(sign pattern,complex sign pattern,ray pattern) are the same in form.     

HCSE method for detection of small carbon–carbon couplings and their signs,comparison with SLAP pulse sequence

Performance of homonuclear coupling sign edited (HCSE) experiment applied to detection of signed carbon–carbon couplings is discussed using a set of already measured samples of nine monosubstituted benzenes. It is shown that coupling sign detection is insensitive to the settings of carbon–carbon polarization transfer delays. The HCSE spectra of ten from the total of 43 measured carbon–carbon couplings were considerably influenced by relaxations and proton–proton strong couplings. These effects are quantitatively discussed. The results of HCSE and SLAP experiments are compared. It is shown that the two methods may complement each other in detection of signed carbon–carbon couplings. Copyright © 2013 John Wiley & Sons, Ltd.     

Sign patterns that allow diagonalizability revisited

Characterization of sign patterns that allow diagonalizability has been a long-standing open problem. In this article, necessary and sufficient conditions for a sign pattern to allow diagonalizability are obtained, in terms of allowing related properties. Some properties of normal sign patterns are considered. In particular, it is shown that normal sign patterns of order up to 3 allow diagonalizability. Two combinatorial necessary conditions for a sign pattern to allow diagonalizability are also presented.     

Configurational assignment in alkyl‐branched sugars via the geminal C,H coupling constants

The measurement of the magnitude and sign of ²J(C,H) couplings offers a reliable way to determine the absolute configuration at a carbon center in a fixed cyclic system. A decrease of the dihedral angle ? in the O—C_A—C_B—H fragment always leads to a change of the ²J(C_A,H_B) coupling to more negative values, independent of the type and position of substituents at the two carbon centers. The orientations of the two substituents at C‐3 of the epimeric pair 1 and 2 were determined unambiguously through the measurement of the geminal coupling constants between C‐3 and the hydrogen atoms at C‐2 and C‐4. In particular, ²J(C‐3,H‐2ax) with ?1.5 Hz, ? = 174° in 1 and ?6.6 Hz, ? = 47° in 2 , and ²J(C‐3,H‐4) with +1.5 Hz, ? = 175° in 1 and ?4.7 Hz, ? = 49° in 2 showed the greatest differences between the two epimers. Both couplings therefore allow the determination of the absolute configuration at C‐3. It should be noted, however, that the size of the coupling constants can be different for dihedral angles of nearly identical size, when there are different numbers of electronegative substituents on the two coupling pathways, i.e. no O‐substituent at C‐2, but one axial O‐substituent at C‐4. It becomes clear that it is not sufficient to measure the magnitude of ²J coupling constants only, but that the sign of the geminal coupling is needed to identify the absolute configuration at a chiral center. The coupling of C‐3 with H‐2eq is not useful for the determination of the configuration at C‐3, as the similarity of the dihedral angles ? (O—C‐3—C‐2—H‐2eq) (57° in 1 and 70° in 2 ) leads to identical coupling constants (?6.1 Hz) for both epimers. Copyright © 2003 John Wiley & Sons, Ltd.