扩声系统调整与声学测试技术

介绍了扩声系统调整的概要与扩声系统声学测试方法的要点,主要从扩声系统组成、各部件调整要点、遵循的原则,扩声系统声学测试技术所遵从的标准、方法、数据处理方法等方面进行了介绍,鉴于目前一些从业人士对扩声系统声学测试技术了解不甚全面,依据GB/T 4959—2011厅堂扩声测量方法,详细介绍了各种测量内容的具体方法与数据处理,并给出了相关的电子表格(Execl)数据处理计算表。     

由实测双耳脉冲响应计算厅堂声学参数

为进行耦台空间声场特性及民族音乐厅堂音质的基础声学研究，与日本神户大学安藤四一声学研究室合作，对广州南方剧院进行了双耳脉冲响应及其它主要声学参数的测试，并根据所测得的双耳脉冲响应计算得出一系列重要的厅堂客观声学指标，为进一步进行主观评价，探讨主客观指标之间相互关系以及实现可听化奠定基础。     

苏州平江市民文化活动中心声学设计

苏州平江市民文化活动中心是一个以会议、报告和放映电影为主,兼有文艺表演的多功能剧场.声学设计既要考虑到会议、报告所需要的语言清晰度问题,又要考虑到文艺演出所需要的音乐丰满度问题.利用odeon声学设计分析软件对该市民文化活动中心的声学问题进行了模拟分析.对建成后的市民文化活动中心进行的测量表明声学设计取得了满意的效果.     

声学头模双耳录音听感效果分析

对比分析了仿真头模录音与简化声学头模录音的听感效果。选择水平面以45°为间隔的8个方向进行录音,通过听感实验判断双耳录音的方向定位正确率以及头中定位的情况。结果表明,声学头模与仿真头模在听感定位上没有显著性的差别,在双耳录音及一些其他场合可采用简化声学头模来代替仿真头模。     

厅堂扩声系统声学特性指标测量等问题的探讨

就GB50371-2006《厅堂扩声系统设计规范》规定的“最大声压级”、“传输频率特性”、“传声增益”、“稳态声场不均匀度”和“系统总噪声”5项基本的声学特性指标,结合GB／T4959—1995《厅堂扩声特性测量方法》规定的测量方法,以使用Nor840 Real Time Analyser声学测量仪器为例,对这5项指标的测量、数据处理和结果表达方式进行阐述。     

三维温度场声学测量重建及计算机仿真

相比单点温度测量而言,温度场的测量更加重要。温度场声学测量是目前最有发展前景的一种温度场测量方法,国内尚无人开展三维温度场声学测量的研究,为此,采用计算机模拟仿真的方法进行了三维温度场声学测量重建。以最小二乘方法为基础构建了三维温度场声学测量重建算法,以安装了32只声发射/接收传感器、并被均匀地分割成64个空间网格的正立方体型区域为测量空间,在考虑和不考虑＂声线弯曲效应＂的情况下,对球对称型模型温度场进行了仿真重建。仿真结果不仅与理论预测符合得较好,而且在考虑了＂声线弯曲效应＂后,温度场的反演精度有了很大提高,说明＂声线弯曲效应＂是影响温度场重建质量的重要因素之一。     

简单、实用、高效 XTZ Room Analyzer Ⅱ Pro

房间声学测量是一项非常复杂的工程,需要借助专业的声学分析仪器及专业人员才能完成。但对于一般的用家而言,专业声学分析仪及专业人员对于他们来说是一件遥不可及的事情。因此,轻便、易用且实惠的便携式声学分析仪就非常适合他们的要求,这类产品的特点是操作简单,能快速地对房间声学的主要参数进行声学分析,让用家能了解到房间的基本声学特性,并作出适当的声学处理,从而得到相对更好的声音。对于这类型的产品,XTZ推出的房间声学分析仪可说是代表之一。它的第一款声学分析仪产品在两年前推出,由于使用上的简便性以及价格上的优势,所以刚推出的时候就受到了热烈的欢迎。而事隔两年后,这款产品得到升级,推出了新一代的Room AnalyzerⅡ。此产品分为标准版和专业版,而我这次所使用的正是Room AnalyzerⅡPro版本。相比起标准版,专业版所用的测试麦克风和声卡的性能更为强大,而且软件部分的功能也更多。因此,测量的精度更高,测量出来的参数也更多。     

混响室的声学设计

混响室是声学专业的实验室用房,它在测量声波无规入射时材料的吸声系数和测量噪声源的声功率级中得到了广泛应用。结合混响室建设的工程实例,介绍了混响室设计中有关体积、体形、吸声、隔声和声扩散等方面的技术问题。测量表明,建成完工后的混响室在声学方面的各项指标均满足或优于国家标准的要求。     

噪声环境下头模录音双耳听感清晰度分析

借助声学头模对不同声源位置条件下的双耳录音信号进行了主、客观分析,结果显示噪声源在头模两侧30°～60°范围内对人耳的干扰最强;语声源对信噪比作用较小,而噪声源对信噪比的影响明显;听感清晰度随声源相对方位角的增大而增大;当语声源和噪声源之间的相对方位角固定时,听感清晰度与双耳信号的信噪比较大值呈显著相关.     

有关歌舞厅声学设计的几个问题

有关歌舞厅声学设计的几个问题建设部建筑设计院曹孝振中华人民共和国文化部颁布了两个行业标准——“歌舞厅扩声系统的声学特性指标与测量方法”（ＷＨ０１－９３），“歌舞厅照明及光污染限定标准“（ＷＨ０２０１－９４），作为歌舞厅分级管理的强制性法规，并据此对歌...     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.