Analysis of Antennas with PBG Substrate

The use of photonic materials has been used in the theory of optical waves. The PBG (Photonic Band Gap) theory and material, was developed recently for optical frequencies and can be easily applied to millimeter waves, microwaves and planar antenna frequencies. The presence of photonic materials as substrate in antennas has some good characteristics such as, supression of light spontaneous emission and suppression of surface waves, allowing the application in planar antenna array. In this work an elaborate analysis using the full wave Transverse Transmission Line - TTL method, that provides efficient and concise results is applied to the planar antennas array with PBG substrate.     

$M$-半群的直觉$(S,T)$-模糊$M$-子半群的性质

K.T.Atanassov在1986年首先引入直觉模糊集的概念,本文利用s-范数和t-范数,引入M-半群的直觉(S,T)-模糊M-子半群的概念,刻画其性质和特征,我们再进一步给出了直觉(S,T)-直积的概念,并由此探讨了一些有意义的相关结论。     

A simple model for high fluence ultra-short pulsed laser metal ablation

The ultra-short laser metal ablation is a very complex process, the complete simulation of which requires applications of complicated hydrodynamics or molecular dynamics models, which, however, are often time-consuming and difficult to apply. For many practical applications, where the laser ablation depth is the main concern, a simplified model that is easy to apply but at the same time can also provide reasonably accurate predictions of ablation depth is very desirable. Such a model has been developed and presented in this paper, which has been found to be applicable for laser pulse duration up to 10 ps based on comparisons of model predictions with experimental measurements.     

The Monitoring System Using FOBG Sensor for The Health of the Rocket

A novel heath monitoring system of the rocket based on fiber optic Bragg gratings is brought forward, its component units and working principle are also described.     

锂锰尖晶石红外光谱的研究

本文对锂锰尖晶石的红外光谱进行了研究。由于锂锰尖晶石的晶体结构属于Fd3m空间群,锂离子占据四面体空隙(8a位置),锰离子占据八面体空隙(16d位置)。根据群论的知识,对锂锰尖晶石晶体中离子的振动方式与红外活性之间的内在关系进行了讨论。并列出了锂锰尖晶石的红外光谱实验数据。通过理论分析,我们推断:位于618.6和501.5cm~(-1)的红外吸收带分别来源于Mn(Ⅳ)-O和Mn(Ⅲ)-O键在晶体中的不对称伸缩振动(单元为Mn(Ⅳ)O_6和Mn(Ⅲ)O_6八面体),位于1124cm~(-1)的弱红外吸收带来源于Li-O键的不对称伸缩(单元为LiO_4四面体)。还有一些低于400cm~(-1)的可能吸收带在400～4000cm~(-1)范围内未能检测到。这一结论的可靠性通过锂锰尖晶石和掺杂的锂锰尖晶石的红外光谱实验数据得到证实。     

Foams and surface rheological properties of β-casein, gliadin and glycinin

Interfacial rheological properties and their suitability for foam production and stability of two vegetable proteins were studied and compared to β-casein. Proteins used ranged from flexible to rigid/globular in the order of β-casein, gliadin and soy glycinin. Experiments were performed at pH 6.7. Network forming properties were characterised by the surface dilational modulus (determined with the ring trough) and the critical falling film length (L_still) at which a stagnant protein film will break. Gliadin had the highest dilational modulus, followed by glycinin and β-casein, whereas glycinin formed the strongest film against fracture in the overflowing cylinder. The rate of decrease in the surface tension was studied at the air–water (Wilhelmy plate method) and the oil–water interface (bursting membrane) and the dynamic surface tension during compression and expansion in the caterpillar. Gliadin had the lowest equilibrium interfacial tensions and β-casein the lowest dynamic surface tension during expansion. Hardly any foam could be formed at a concentration of 0.1 g/l by shaking. At a concentration of 1.4 g/l most foam was formed by β-casein, followed by gliadin and glycinin. It seems that in the first place the rate of adsorption is important for foam formation. For the vegetable proteins, adsorption was slow. This resulted in lower foamability, especially for glycinin.     

Ag-Bi高温超导线材转变温度的测量

介绍了 Bi系银包套高温超导线材的电阻温度特性 ,用测电阻和电磁感应两种方法分别测量了材料的超导转变温度 ,电磁感应法测量曲线上台阶的出现表明材料中 Bi(2 2 2 3)和 Bi(2 2 12 )两相的存在。     

Adaptive regulation for deterministic systems

For the linear deterministic system with unknown orders and coefficients adaptive controls are given so that the closed-loop system is stabilized and the unknown parameters are consistently estimated. Moreover, if the parameter estimation is ignored, then the system input and output can be reduced to zero with an exponential rate.This project is supported by the National Natural Science Foundation of China.In Commemoration of the 15th Anniversary of the Acta Mathematicae Applicatae Sinica.     

Fully-angular polyhex chains with minimal total π-electron energy

By Hückel molecular orbital (HMO) theory, the calculation of the total energy of all π-electrons in conjugated hydrocarbons can be reduced to that of E(G)=|λ₁|+|λ₂|+?+|λn|, where λi are the eigenvalues of the corresponding graph G. Denote by Ψn the set of all fully-angular polyhex chains with n hexagons. In this paper, we show that Hn has the minimum total π-electron energy among chains in Ψn, where Hn is the helicene chain.     

Sharp condition of global existence for second-order derivative nonlinear Schrödinger equations in two space dimensions

This paper discusses a class of second-order derivative nonlinear Schrödinger equations which are used to describe the upper-hybrid oscillation propagation. By establishing a variational problem, applying the potential well argument and the concavity method, we prove that there exists a sharp condition for global existence and blow-up of the solutions to the nonlinear Schrödinger equation. In addition, we also answer the question: how small are the initial data, the global solutions exist?