Ordering trees with n vertices and matching number q by their largest Laplacian eigenvalues

Denote by T_n,q the set of trees with n vertices and matching number q. Guo [On the Laplacian spectral radius of a tree, Linear Algebra Appl. 368 (2003) 379-385] gave the tree in T_n,q with the greatest value of the largest Laplacian eigenvalue. In this paper, we give another proof of this result. Using our method, we can go further beyond Guo by giving the tree in T_n,q with the second largest value of the largest Laplacian eigenvalue.     

Fluorimetric study of interaction of benzidine with trypsin

The interaction of benzidine (BEN) with trypsin was studied by fluorescence spectrum. It was shown that BEN has quenched the fluorescence launching from trypsin by reacting with it and forming a certain kind of new complex. The quenching and energy transfer mechanisms were discussed. The binding constants and thermodynamic parameters at three different temperatures, the binding locality, and the binding power were obtained. The conformation of trypsin was discussed by synchronous and three-dimensional fluorescence techniques.     

硝基苯在纳米炭黑上的吸附特征

利用炭黑作吸附剂,考察吸附质流速和硝酸处理浓度对炭黑吸附有机废水中硝基苯的影响,确定了最佳吸附处理条件,比较了不同炭素材料的吸附性能。实验结果表明:与炭管、椰壳活性炭和颗粒活性炭3种炭素材料相比,炭黑对硝基苯具有更佳的吸附性能。XRD、BET表征结果表明炭黑表面存在大约40nm介孔结构,毛细凝聚在吸附中起到了重要作用。     

矩形网格上二元有理插值的表现公式

运用迭加算法给出矩形网格上二元有理插值函数的表现公式,特别给出了在对角情形下使用迭加算法得到的插值公式.这种方法具有较大的灵活性,且易于编写程序,便于实际应用.     

Lateral shifting in one dimensional chiral photonic crystal

We report the lateral shifts of the transmitted waves in a one dimensional chiral photonic crystal by using the stationary-phase approach. It is revealed that two kinds of lateral shifts are observed due to the existence of cross coupling in chiral materials, which is different from what has been observed in previous non-chiral photonic crystals. Unlike the chiral slab, the positions of lateral shift peaks are closely related to the band edges of band gap characteristics of periodic structure and lateral shifts can be positive as well as negative. Besides, the lateral shifts show a strong dependence on the chiral factor, which varies the lateral shift peaks in both magnitudes and positions. These features are desirable for future device applications.     

Fast topological imaging

Mathematical optimization methods based on the topological sensitivity analysis have been used to develop innovative ultrasonic imaging methods. With a single illumination of the medium, they have proved experimentally to yield a lateral resolution comparable to classical multiple-illumination techniques. As these methods are based on the numerical simulations of two wave fields, they require extensive computation. A time-domain finite-difference scheme is usually used for that purpose. This paper presents the development of an experimental imaging method based on the topological sensitivity. The numerical cost is reduced by replacing the numerical simulations by simple mathematical operations between the radiation patterns of the array’s transducers and the frequency-domain signals to be emitted. These radiation patterns are preliminary computed once and for all. They were obtained with a finite element model for the anisotropic elastodynamic case and with semi-analytical integrations for the acoustic case. Experimental results are presented for a composite material sample and for a prefractal network immersed in water. A lateral resolution below 2.5 times the wavelength is obtained with a single plane wave illumination. The method is also applied with multiple illuminations, so that objects hidden in complex media can be investigated.     

Ti/Sn（1-x）IrxO2电极制备及电生活性氯特性

通过热分解法制备了Ti/Sn(1-x)IrxO2电极,应用SEM观察了电极的表面形貌,通过线性伏安法、循环伏安法等实验方法测试了电极的电化学性能。实验结果表明,Ti/Sn0.7Ir0.3O2电极具有较好的析氯活性;电解产生的活性氯浓度随电流密度的增加先增加后降低;升高电解温度不利于活性氯的产生。     

激光拉曼光谱内标法测定红辣椒表面的农残甲基毒死蜱

利用激光拉曼光谱对蔬菜红辣椒表面的农药甲基毒死蜱模拟残留进行了测定,选择红辣椒中富含的β-胡萝卜素的1444.0cm^-1作为内标信号,与农药甲基毒死蜱本身的649.4cm^-1特征拉曼光谱组成相对光谱强度,结果表明相对光谱强度与农药甲基毒死蜱残留量有着很好的线性关系,其线性关系为R=0.143V+2.023,线性相关系数为0.9895。研究表明利用激光拉曼光谱内标法在特定条件下可用于农药残留的测定。