扬声器及其系统频率响应的统计学特性参数

随着计算机辅助测试（CAT）技术的发展，直接测量扬声器及其系统的频率响应特性函数（SPL）已经变得容易，通过对其进行统计学分析，可以得出新和一组有用的参数，包括SPL标准差、SPL离散系统、SPL峰度系数等。这些参数如果能够推广为扬声器及其系统的常用性能参数，将能够填补Thiele-Small参数的一些盲点，给质量标准的制订、工程的应用等都带来了不少方便。     

天津体育中心扩声系统设计

本文简要介绍天津体育中心总体扩声系统的构成，并分别对主馆和大练习馆在扩声系统设计中的特点作了详细的说明。对各自建筑结构特点，容易产生和声学缺陷所采取的措施进行了阐述。     

弯曲振动型薄板扬声器的工作原理

首先求得矩形薄板弯曲振动偏微分方程的解，分析了薄板弯曲振动的简正频率和它的振型，最后讨论了弯曲振动型薄板扬声器的性能并给出NXT扬声器的相应技术特性，其应用前景广阔。     

一种新型的音频电声实验装置

探究并设计制作了一种新型的音频电声实验装置,装置由电热层、绝缘层和导热层组成。将音频电功率信号接入电热层．利用焦耳定律及各层材料不同的热力学特性,使电热层表面附近的气体产生了与音频电功率信号一致的声信号。实验结果表明装置具有较好的音频电声转换功能,与传统的扬声器相比,具有结构简单,无任何振动部件等优点,有较大的研究意义及广阔的应用前景。     

国家体育场（“鸟巢”）扬声器系统的研究、设计、制造、使用（一）

对国家体育场（“鸟巢”）在北京奥运会所用扬声器系统研制和使用进行了全面总结。对相关线阵列扬声器系统进行了理论分析、梳理和探讨。说明了对设计中遇到的问题与对策,对设计过程中自主开发的专利予以解说并介绍了扬声器箱在体育场安装和使用的情况。     

机顶盒静电问题探讨及解决方案

针对一款塑料外壳的网络机顶盒受到ESD干扰时易死机的具体问题进行了理论分析,并通过调整PCB叠层和布局,提高了系统可靠性,最终使该产品通过了静电测试。     

Natural Convection from a Corrugated Heated Surface at the Bottom of Vented Rectangular Enclosure

Natural convection heat transfer characteristics enclosures from a tilted rectangular enclosure heated at the corrugated bottom wall and vented by uniform slots opening at the top wall are experimentally investigated. The experiments were carried out to study the effects of the angle of opening of the corrugated surface, opening ratio, enclosure's tilt angle, and Rayleigh number on the passive cooling of the enclosure. The experiments were carried out at Rayleigh numbers ranging from 2 × 10⁸ to 1.52 × 10⁹ for enclosure tilt angles ranging from 0° to 90° and angle of opening of corrugated surface ranging from 0° to 25°. The top venting arrangement was studied at different opening ratios of 1, 0.75, 0.5, and 0.25. The results gave an optimum angle of opening of the corrugated surface at which Nusselt number is maximum.     

Comparison principles applied to obstacle problems with penalties

Penalty methods form a well known technique to embed elliptic variational inequality problems into a family of variational equations (cf. [6], [13], [17]). Using the specific inverse monotonicity properties of these problems L _∞-bounds for the convergence can be derived by means of comparison solutions. Lagrange duality is applied to estimate parameters involved.

For piecewise linear finite elements applied on weakly acute triangulations in combination with mass lumping the inverse monotonicity of the obstacle problems can be transferred to its discretization. This forms the base of similar error estimations in the maximum norm for the penalty method applied to the discrete problem.

The technique of comparison solutions combined with the uniform boundedness of the Lagrange multipliers leads to decoupled convergence estimations with respect to the discretization and penalization parameters.     

扬声器阵列声波导有效辐射率分析

通常为扬声器阵列的压缩驱动单元安装声波导,以提高阵列的性能.分析了声波导的等效长度,并且提出声波导的有效辐射率这一评价指标,以反映声波导的利用率.还提出测量声波导有效辐射率的指向性拟合方法,实验表明,和原有的特定角度方法相比,指向性拟合方法更加准确可靠.     

基于Android的手机扬声器频响补偿校正

利用数字处理的方法,通过Java开发音频播放录音平台结合实验室标准音频设备获取手机扬声器有关数据,在Matlab平台进行分析以获悉手机扬声器频率响应特性,并对频率响应曲线中相对于目标响应曲线的待补偿区域,结合GA等优化函数设计对应滤波器组进行补偿校正并将滤波器组嵌入到Android手机音频应用软件中以改善手机扬声器性能,提升其音质表现.