A Lower Bound Sequence for the Minimum Eigenvalue of Hadamard Product of an M-Matrix and its Inverse

Czechoslovak Mathematical Journal - We propose a lower bound sequence for the minimum eigenvalue of Hadamard product of an M-matrix and its inverse, in terms of an S-type eigenvalues inclusion set...     

Synthesis and Characterization of Task‐Specific Ionic Liquids Possessing Two Brönsted Acid Sites

Abstract

Task‐specific ionic liquids possessing two Brönsted acid sites with –COOH, HSO^? ₄, or H₂PO^? ₄ groups have been designed, synthesized, and characterized. Under mild conditions and without any additional organic solvent, the esterification of isopropanol by chloroacetic acid could be carried out in these new task‐specific ionic liquids. In comparison with most of acidic ionic liquids in current use, these ionic liquids are halogen free and more environmentally benign as media and catalysts.     

Perovskite-type (Ba<Subscript>0.15</Subscript>Sr<Subscript>0.85</Subscript>)(B<Subscript>0.15</Subscript>Co<Subscript>0.85</Subscript>)O<Subscript>3 − δ</Subscript> (B = Ti,Nb) oxides: structural stability,oxygen nonstoichiometry,and oxygen sorption/desorption properties

The perovskite-type Ba- and Ti/Nb-doped (Ba_0.15Sr_0.85)(B_0.15Co_0.85)O_3 ? δ (B = Ti, Nb) oxides were synthesized successfully by the solid-state reaction method. Crystal structure, elemental compositions, and oxygen nonstoichiometry of the as-synthesized (Ba_0.15Sr_0.85)(B_0.15Co_0.85)O_3 ? δ (B = Ti, Nb) oxides were investigated by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), inductively coupled plasma (ICP)-atomic emission spectrometry, thermogravimetry (TG), and iodometric titration. XRD results demonstrate that the as-obtained (Ba_0.15Sr_0.85)(B_0.15Co_0.85)O_3 ? δ (B = Ti, Nb) oxides possess purely cubic perovskite-type structures. The temperature-swing oxygen sorption/desorption properties of the as-synthesized (Ba_0.15Sr_0.85)(B_0.15Co_0.85)O_3 ? δ (B = Ti, Nb) perovskite-type oxides were studied by the dynamic TG. Results show that the structural stability of the co-doped (Ba_0.15Sr_0.85)(B_0.15Co_0.85)O_3 ? δ (B = Ti, Nb) oxides is improved greatly, and the high oxygen sorption capacity for the perovskite-type (Ba_0.15Sr_0.85)(B_0.15Co_0.85)O_3 ? δ (B = Ti, Nb) oxides is also obtained between 300 and 950 °C in air.     

3-芳亚甲基联氨羰基-5-(对位取代苯基)-吡唑衍生物的 合成、结构和生物活性

以4-取代苯乙酮及草酸二乙酯为起始原料, 设计合成了20个新的3-芳亚甲基联氨羰基-5-(对位取代苯基)-吡唑衍生物, 产率较高. 所合成的化合物经元素分析, IR, 1H NMR对其结构进行了表征, 化合物4b, 4h还通过X-ray单晶衍射进一步确证了其结构. 初步生物活性实验结果表明, 所合成的化合物对绿豆发芽过程有着较好的生长调节作用.     

非奇异H-矩阵的新判据

1引言与记号设A=(a_(ij))∈C~(n×n),记N={1,2,…,n},∧_i(?)∧_i(A)=sum from j≠i|a_(ij)|,S_i(?)S_i(A)=sum from j≠i|a_(ij)|,(?)i,j∈N。若|a_(ij)>∧_i(A),(?)i∈N,则称A为严格对角占优矩阵。     

辐射驱动内爆温度源脉冲整形研究

辐射驱动温度源脉冲整形是获得高压缩比的重要途径。本文从脉冲整形的基本原理出发，采用数值模拟方法，给出适合于神光Ⅲ装置内爆实验的辐射驱动温度源脉冲整形曲线。     

四元数矩阵的Schur积的奇异值和的估计

本文得到了四元数矩阵Schur积的奇异值和的估计.     

一类非奇异H-矩阵判定的新条件

非奇异H-矩阵是在许多领域具有广泛应用的重要矩阵类,但实际判定一个非奇异H-矩阵是十分困难的.在本文中,我们给出了一类关于非奇异H-矩阵新的判定条件,改进了近期的相关结果,并用数值例子说明了文中结果判定范围的更广泛性.     

SARS CoV内对照RNA病毒样颗粒的构建和表达

在SARS-CoV的核酸检测方法中,由于普遍缺乏安全、稳定、特异的内对照,而不能对样品处理、反转录、扩增以及定量检测实施全程监控。构建的病毒样核蛋白颗粒内对照,能够对SARS-CoV临床检测实施监控。本文通过克隆1.7Kb大肠杆菌噬菌体MS2的装配蛋白和壳蛋白基因以及SARS冠状病毒经过突变产生的270bp内对照片断,并将这些基因连接到载体pTrc99a上表达,进行纯化、定量分析、RT-PCR检测和稳定性试验。获得SARS内对照病毒样核蛋白颗粒,在人血清和SM缓冲液中37℃稳定性可达到30天,能抵抗核糖核酸酶降解。将内对照颗粒加入临床样本中一同检测,能够对检测的全过程(样品处理、反转录和PCR)有效进行监控,与SARS-CoV没有交叉反应。研究表明制备的该病毒样核蛋白颗粒稳定、安全、可靠,可作为SARS冠状病毒RT-PCR检测、定量分析的有效内对照参考品。     

A structural characterization of real k-potent matrices

Some well-known characterizations of nonnegative k-potent matrices have been obtained by Flor [P. Flor, On groups of nonnegative matrices, Compositio Math. 21 (1969), pp. 376–382.] and Jeter and Pye [M. Jeter and W. Pye, Nonnegative (s,?t)-potent matrices, Linear Algebra Appl. 45 (1982), pp. 109–121.]. In this article, we obtain a structural characterization of a real k-potent matrix A, provided that (sgn(A)) ^k+1 is unambiguously defined, regardless of whether A is nonnegative or not.