用频谱分析法测量声光驻波调制器的调制度

从调制的基本概念出发，指出声光驻波调制器件为宽带频率调制型。讨论了调制度概念的成立条件和适用范围。理论上求出其成立条件为ｖ＜０．９（ｖ＝２πＬ△ｕ／λ为衍射光强Ｉ（θ，ｔ）中的自变量）。鉴于一般驻波型声光器件都是含有一定的行波成份，但行波声场和驻波声场在拉曼－奈斯衍射范围内衍射角均遵从ｓｉｎθｍｉ＝土ｍλ／，故两者在空间上是无法分开的。文中给出了从频域上测量调制度Ｍ的一种新方法。并给出了零级和一般衍射光的测量值。     

Approach to saturation of the magnetization of dilute AuFe alloys

We present a reinterpretation of our recent measurements of the magnetic properties of some dilute AuFe alloys. We find that the observed approach to saturation of the magnetization for these AuFe alloys can be understood if both single-impurity (Kondo) effects and effects due to interactions between impurities via the Rudeman-Kittel-Kasuya-Yosida (RKKY) interaction, V(r) = (V₀ cos 2k_Fr)/r³, are properly included in the analysis. The analysis yields for the strength of the RKKY interaction V₀ = (1.1 ± 0.3) × 10^-36ergcm³, for the s-d exchange parameter |J| = (1.9 ± 0.3) eV, and for the Kondo temperature T_K = (0.8 ± 0.1) K. We conclude that mean free path effects do not significantly influence the observed approach to saturation of the magnetization for the AuFe alloys studied.     

An Inexact SQP Newton Method for Convex SC<Superscript>1</Superscript> Minimization Problems

In this paper, we present a globally and superlinearly convergent inexact SQP Newton method for solving large scale convex SC ¹ minimization problems under mild conditions. In particular, the BD-regularity assumption made by Pang and Qi in Journal of Optimization Theory and Applications, 85 (1995), pp. 633–648 is replaced by a much more realistic assumption. Our numerical experiments conducted on least squares semidefinite programming with lower and upper bounds demonstrate that our inexact SQP Newton method is much more efficient than its exact version and is competitive with existing methods when the number of simple constraints is very large.     

Analysis of the dynamics of a delayed HIV pathogenesis model

In this paper, considering full Logistic proliferation of CD4⁺ T cells, we study an HIV pathogenesis model with antiretroviral therapy and HIV replication time. We first analyze the existence and stability of the equilibrium, and then investigate the effect of the time delay on the stability of the infected steady state. Sufficient conditions are given to ensure that the infected steady state is asymptotically stable for all delay. Furthermore, we apply the Nyquist criterion to estimate the length of delay for which stability continues to hold, and investigate the existence of Hopf bifurcation by using a delay τ as a bifurcation parameter. Finally, numerical simulations are presented to illustrate the main results.     

New Algorithm for Computing LQ Suboptimal Output Feedback Gains of Decentralized Control Systems

In this paper, the problem of computing the suboptimal output feedback gains of decentralized control systems is investigated. First, the problem is formulated. Then, the gradient matrices based on the index function are derived and a new algorithm is established based on some nice properties. This algorithm shows that a suboptimal gain can be computed by solving several ordinary differential equations (ODEs). In order to find an initial condition for the ODEs, an algorithm for finding a stabilizing output feedback gain is exploited, and the convergence of this algorithm is discussed. Finally, an example is given to illustrate the proposed algorithm.     

High-brightness white light-emitting organic electroluminescent devices using poly(N-vinylcarbazole) as a hole-transporter

A white light-emitting organic electroluminescent (EL) device with multilayer thin-film structure, which shows high-brightness and high-efficiency, is demonstrated. The device structure of glass substrate/indium–tin oxide/poly(N-vinylcarbazole) (PVK)/1,1,4,4-tetraphenyl-1,3-butadiene/8-(quinolinolate)-aluminum (Alq) doped with 5,6,11,12-tetraphenylnaphthacene/Alq/Mg/Al was employed. The turn-on voltage is as low as 2.5 V. The white light emission covers a wide range of the visible region, and the Commission Internationale de 1' Eclairage coordinates of the emitted light are (0.319, 0.332) at 10 V. Bright white light, over 20 000 cd/m², was successfully obtained at about 18 V, and the maximum efficiency reaches to 1.24 lm/W at 9 V. The reasons of obtaining high level EL properties of our device have been discussed.     

高阻恒流LED产生亚泊松光的理论研究

本文研究高阻恒流源驱动的光发射二极管（ＬＥＤ）的输出光场的振幅噪声压缩与电，光量子效率，漏电流效应，泵浦残余噪声频率的关系，指出高阻恒流技术不仅使任意纵模产生振幅噪声压缩，而且由于仅在高阻恒流下各纵模间存在负量子相关，使得ＬＥＤ总输出光场的振幅噪声压缩加深。     

光在大分子聚合物中的解偏和散射

文章报道了光在大分子聚合物中的前向散射和解偏现象,并用Mie散射和Fraunhofe衍射理论对其进行了解释,提出了小角度散射的光解偏理论。     

双通道计时法测量刚体转动惯量实验误差分析

本文指出,双通道计时法测量刚体转动惯量的误差比单通道测量误差小;此时,外力矩中不考虑加速度α时引入的测量偏差更是不能忽略,要对测量值进行修正．