稳定受迫振动中的能量转换

将强迫分解成超前位移π／２和位移相同或反相的两个分量，通过对两分力作功的定量计算，可以方便地讨论受迫振动中的能量转换，并能对共振作出较的物理解释。     

ZnO纳米线的制备

利用磁控溅射技术在Si衬底上沉积的锌膜进行热氧化后,得到一维ZnO纳米线。     

Special complex open-cavity and low-magnetic-field high-powergyrotron

A theory is proposed for the special complex cavity; it is in the form of a single resonant circuit having a TE_0n&lrarr2;TE_0,n+p mode converter and it features excellent mode selectivity, high power capability, and an asymmetric triangle profile of the RF field that is favourable to efficient operation for a 35-GHz second-harmonic gyromonotron employing this complex cavity with TE₀₃ mode output are numerically illustrated and experimentally demonstrated. Power as high as 200 kW and efficiency as high as 30% have been obtained. These experimental results are record values for a gyrotron operating at the second-harmonic millimeter wavelength. Implications of the single-resonant complex cavity for the fundamental harmonic and third-harmonic high-average-power gyrotron design are discussed     

Temperature overshoots for a 4-velocity unidimensional discrete Boltzmann model

We propose a 4-velocity unidimensional discrete Boltzmann model with two different speeds 2, 1 and two different masses 1, 2. With the three conservation laws of mass, momentum, and energy satisfied, we can introduce a nontrivial temperature. First, we determine the similarity shock waves satisfying physical properties: positivity, shock stability, inequalities of the subsonic and supersonic flows, increase or decrease of both mass and temperature across the shock. It results that either the speed of the shock front is higher than the speed 1 of the slow particles and the shocks are compressive or less than 1 and the shocks are rarefactive. We observe overshoots of the temperature, across the shock, with bumps higher and higher as the shock front speed increases. Second, we study the (1+1)-dimensional shock waves. They represent the superposition and collision of two compressive shocks traveling in opposite directions and we observe temperature overshoots for not too large times.     

对"坚持时代性与基础性相结合原则"的思考与认识--高中物理改革教材编写中的一些体会

2003年8月开始，我应邀参加了物理通报教材研究中心组织的高中物理改革教材的编写工作．在编写过程中，如何领会与掌握“坚持时代性与基础性相结合原则”一直是大家关注的一个热点问题．本文介绍一下我对这一问题的思考与认识以及在教材编写中的一些具体做法．抛砖引玉，希望更多同志参与探讨．     

Syndiotactic polymerization of styrene catalyzed by alkenyl‐substituted cyclopentadienyltitanium trichlorides

CH₂?CHCH₂CpTiCl₃ (1), CH₂?CHCH₂CH₂CpTiCl₃ (2) and CH₃CH₂CH₃CpTiCl₃ (3) have been synthesized and characterized. The influence of the alkenyl substituent groups on the catalyst activities in the syndiotactic polymerization of styrene was investigated. The catalyst activities decreased in the order CH₂?CHCH₂CH₂CpTiCl₃ > CH₃CH₂CH₂CH₂CpTiCl₃ > CH₃CH₂CH₂CpTiCl₃ > CH₂?CHCH₂CpTiCl₃ (Cp?C₅H₄). By using complex 1, the dependence of the activity on the concentration of methylaluminoxane, triisobutylaluminum and diisobutylaluminum hydride was investigated. Copyright © 2003 John Wiley & Sons, Ltd.     

MNA/PMMA有机薄膜光波导

研究出MNA/PMMA有机薄膜光波导。用棱镜耦合器进行了波导参数的测量,发现薄膜呈现各向异性,有较大的双折射。