直观显示摩擦力实验的改进

对文献^[1]中用弹簧秤直观显示摩擦力的实验进行了改进，成功地解决了原实验在滑动摩擦力的测量过程中不易读数的问题。     

Study on electrochemical fingerprints of different Chrysanthemums by using B-Z oscillation system

A sensitive and convenient method for the study of electrochemical fingerprints of Chrysanthemums from different regions is studied by Belousov-Zhabotinskii(B-Z) oscillation system with malonate as a dissipative material.The results indicated that the electrochemical fingerprints of Chrysanthemums from different regions show significantly different characteristics,and can be used to identify the regions of Chrysanthemums.     

Nonoscillation criteria for second‐order nonlinear differential equations with decaying coefficients

This paper is concerned with the problem of deciding conditions on the coefficient q (t) and the nonlinear term g (x) which ensure that all nontrivial solutions of the equation (|x ′|^α–1x ′)′ + q (t)g (x) = 0, α > 0, are nonoscillatory. The nonlinear term g (x) is not imposed no assumption except for the continuity and the sign condition xg (x) > 0 if x ≠ 0. In our problem, it is important to examine the relation between the decay of q (t) and the growth of g (x). Our main result extends some nonoscillation theorem for the generalised Emden–Fowler equation. Proof is given by means of some Liapunov functions and phase‐plane analysis. A simple example is includes to show that the monotonicity of g (x) is not essential in our problem. Finally, elliptic equations with the m ‐Laplacian operator are discussed as an application to our results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Study on Electrochemical Fingerprints and Identification of Different Varieties of Rice and Mouldy Rice by B‐Z Oscillation Reaction System

The electrochemical fingerprints of different varieties of rice and mouldy rice were studied by Belousov‐Zhabotinskii (B‐Z) oscillation reaction system with malonic acid as dissipative material under the condition of constant temperature. The results indicated that the chemical composition of rice may influence the kinetic parameters of the B‐Z oscillation reaction, which lead to the electrochemical fingerprint characteristic parameters and the intuitive information changes obviously. The varieties of rice and mouldy rice can be identified and evaluated by the difference of the electrochemical characteristic information.     

二阶非线性摄动微分方程的振动性定理

研究了一类二阶非线性摄动微分方程解的振动性,建立了两个新的振动性定理,推广和改进了已有的结果.     

线宽增强因子对外光注入半导体激光器非线性单周期振荡特性的影响

线宽增强因子是影响半导体激光器输出特性的一个重要参量,不同材料不同结构类型的半导体激光器的线宽增强因子有较大的差异.利用光注入半导体激光器的单模速率方程模型,数值研究了线宽增强因子对外光注入半导体激光器的非线性单周期振荡特性的影响.结果表明:外光注入半导体激光器的动态特性对线宽增强因子的变化极为敏感,随着线宽增强因子的增加,在负失谐注入范围内单周期振荡区域显著增大,同时注入锁定的稳态输出被大大抑制.分析了线宽增强因子对非线性单周期振荡光谱特性和振荡频率的影响,结果表明:随着半导体激光器线宽增强因子的增大,单周期振荡的频率越大|当线宽增强因子不变时,单周期振荡的频率随注入光强度和频率失谐的增加而增加.     

实现振幅控制量子干涉的实验方案

传统意义的光干涉是由两束干涉光的位相差来决定。近年来量子干涉不仅与入射场的位相差,而且与入射场的振幅有关这一全新的概念被提出。本文从压缩态与相干态干涉的角度出发,给出了实现振幅控制量子干涉的两个方案。我们既可以通过光学参量放大器来放大一个相干态的方式,也可以采用压缩态与相干态在分束器上直接干涉的方式来实现。且计算的结果也表明,得到N个光子数的福克态概率随振幅的位移量大小呈周期性变化。     

100-nm T-gate InAlAs/InGaAs InP-based HEMTs with f_T = 249 GHz and f_(max) = 415 GHz

InAlAs/InGaAs high electron mobility transistors(HEMTs) on an InP substrate with well-balanced cutoff frequency fTand maximum oscillation frequency fmax are reported. An InAlAs/InGaAs HEMT with 100-nm gate length and gate width of 2 × 50 μm shows excellent DC characteristics, including full channel current of 724 mA/mm, extrinsic maximum transconductance gm.max of 1051 mS/mm, and drain–gate breakdown voltage BVDG of 5.92 V. In addition, this device exhibits fT= 249 GHz and fmax = 415 GHz. These results were obtained by fabricating an asymmetrically recessed gate and minimizing the parasitic resistances. The specific Ohmic contact resistance was reduced to 0.031 Ω·mm. Moreover,the fTobtained in this work is the highest ever reported in 100-nm gate length InAlAs/InGaAs InP-based HEMTs. The outstanding gm.max, fT, fmax, and good BVDG make the device suitable for applications in low noise amplifiers, power amplifiers, and high speed circuits.     

Oscillation criteria of neutral type impulsive hyperbolic equations

In this paper, oscillatory properties of all solutions for neutral type impulsive hyperbolic equations with several delays under the Robin boundary condition are investigated and several new sufficient conditions for oscillation are presented.