ON THE EXPECTED DISCOUNTED PENALTY FUNCTION IN A MARKOV-DEPENDENT RISK MODEL WITH CONSTANT DIVIDEND BARRIER

This article considers a Markov-dependent risk model with a constant dividend barrier. A system of integro-differential equations with boundary conditions satisfied by the expected discounted penalty function, with given initial environment state, is derived and solved. Explicit formulas for the discounted penalty function are obtained when the initial surplus is zero or when all the claim amount distributions are from rational family. In two state model, numerical illustrations with exponential claim amounts are given.     

Scheme for teleportation of unknown states of trapped ion

A scheme is presented for teleporting an unknown state in a trapped ion system. The scheme only requires a single laser beam. It allows the trap to be in any state with a few phonons, e.g. a thermal motion. Furthermore, it works in the regime, where the Rabi frequency of the laser is on the order of the trap frequency. Thus, the teleportation speed is greatly increased, which is important for decreasing the decoherence effect. This idea can also be used to teleport an unknown ionic entangled state.     

Dynamical study on charge injection and transport in a metal/polythiophene/metal structure

The dynamical process of charge injection from metal electrode to a nondegenerate polymer in a metal/polythiophene （PT）/metal structure has been investigated by using a nonadiabatic dynamic approach. It is found that the injected charges form wave packets due to the strong electron-lattice interaction in PT. We demonstrate that the dynamical formation of the wave packet sensitively depends on the strength of applied voltage, the electric field, and the contact between PT and electrode. At a strength of the electric field more than 3.0 × 10^4 V/cm, the carriers can be ejected from the PT into the right electrode. At an electric field more than 3.0 × 10^5 V/cm, the wave packet cannot form while it moves rapidly to the right PT/metal interface. It is shown that the ejected quantity of charge is noninteger.     

Temperature dependent phonon modes and ionicity of LiGaO2 single crystal

This paper reports that polarized far-infrared reflectivity measurements have been done on LiGaO2 single crystal along two crystalline taxes at different temperatures. The temperature dependent frequencies of the longitudinal and transverse optical phonon have been obtained from the real part of optical conductivity and the loss function respectively. A small Drude component is observed at frequency below 300 cm^-1 which could arise from Li ions or oxygen deficiencies. The ionicity of LiGaO2 has been studied from the analysis of the Born effective charge of different ions.     

可调谐激光晶体GSGG∶Cr3+在低温下光谱压致移位的理论研究

采用单组态坐标模型,应用由对角化d3能量矩阵而获得的波函数,同时考虑了自旋-轨道相互作用和电-声子耦合,并定量计入了4T2与2T1各电子态对R线的影响以及局域压缩率和整体压缩率之间的差异,从微观的角度,研究了GSGG∶Cr3+低温下光谱结构的特点以及压力导致的R1线和4T2宽带的移位.理论计算的结果与实验符合较好,R线的常压位置及其分裂、R1线的压致移位及其"反转"现象和4T2宽带的压致移位都得到了合理的解释.     

血液中声参量测量值与混合定则的比较

本文测量了猪、羊、牛血液的声速和非线性声参量以及血液中水、蛋白质、脂肪的含量.把结果与Apfel和Sehgal声参量混合定则作了比较.指出两个混合定则能够反映血液声参量与其水、蛋白质、脂肪含量的关系,但在精确定量上与实验尚有距离.     

声致生物学效应

本文较全面的介绍了声致生物效应的研究内容，包括超声生物效应，次声生物效应以及噪声生物效应，并综述了近年来这三个方面的研究进展．简要地分析了其作用机理与一些疾病的关系．文章最后阐述了声致生物效应研究的意义．     

管中的驻波:管乐器和簧乐器--物理与音乐之三

管乐器是乐器中的一大家族，主要由各种形式的管状体和激声系统构成．它们的共同特点是利用管中的空气柱振动作为声源，而激声器和管体的形状则各不相同．管乐器可分为两个系列：木管乐器和铜管乐器，它们的主要区别见表1．     

控制颈部开口横截面积的可变共振型消声装置

以前,大多数消声器都是被动式的。而最近对主动式消声器的研究日益多起来了。主动式消声法可分两种方式:一种是采用扬声器等做附加声源,产生与应消去噪声的声压波形反相位的声压波形,使两者相互抵消的方式。这种方式,从理论上说,在相当宽的低频带范围具有消声能力。但是,实际上存在着附加声源的耐久性及其所产生低频波等有关问题。另一种是根据声噪声的频率特性调整消声器的形状方式。本文就是研究这种方式加上控制技术的可变共振腔消声法。这是根据周期性噪声的周期变化,改变共振型消声器的共振腔容积,使共振频率跟踪噪声的主要频率,让共振型消声器的消声能力最大限度地发挥出来。这     

声频工程专业学术交流会在苏州召开

中国电子学会、中国声学学会声频工程专业学会委员会首届年会暨学术交流会于九○年十一月十九日至甘二日在苏州召开。出席会议的代表共38人,其中委员会委员23人,特邀代表15人。会议回顾了学会自1989年成立以来的工作情况,对组织机构进行了调整并作了人事变动,研究了学会今后工作要点,会议传达了中国电子学会第九次工作会议情况及有关精神,会议期间进行了学术交流,共收到论文18篇,其中在会上宣读17篇,内容包括近代电声测量技术,扩声系统设计,音质评价和产品设计等,论文涉及面广,具有较高的学术水平,一些文章既有较高的理论性,通过实