世界一点也不稀奇

从前,当我还是一个小孩的时候,我胆小而且害羞。我喜欢一个人躲在一间阴湿的小房间内。我常常是一个人独自呆着。后来有一天,我不得不离开我的小房间了。我来到一个月台上。我将要到一个新的地方去。我害     

多媒体教室的声场环境分析与优化

本文从多媒体教室声场的组成及特点,分析了教室的声场存在环境对传递教学信息质量的主要影响因素;针对在新建或改建多媒体教室过程中,不但要重视设备的配置,而且要综合考虑教室声场环境的基本要求,提出解决多媒体教室声场存在问题的适用方法。     

BABY屋的“+ -×÷”

QQ是一个人见人爱的两岁宝宝,他拥有一间10平米的小房间,那是他快乐的小天地,是妈妈集思广益为QQ精心准备的,但是天性好动的宝贝也给"后勤管家"妈妈制造了很多麻烦,于是小房间总在不断地改良。一起来听听QQ妈妈的改良心得吧!     

我的宝贝

在我的小房间里,有一个精致的小木盒。小木盒里有一张奖状,它就是我的宝贝。我5岁那年,妈妈给我报了手风琴班。我很喜欢拉手风琴,从5岁拉到10岁,因拉琴获得的奖状     

圆锥形凹面聚束声透镜优化设计的初步研究

本文对圆锥形凹面聚束声透镜的优化设计作定量的初步研究。应用瑞利－索末菲衍射公式对其不同面形参数下的声场进行了数值计算，详细地分析了透镜的面形参数与其声场分布特征间的关系，根据在声场中尽可能长的距离范围内，获得声束宽度较小，旁瓣水平适中的聚束声束的要求，提出了透镜的优化面形参数。     

较大孔径薄声透镜声场的瑞利——索末菲衍射公式

本文从波动理论出发，应用惠更斯－菲涅耳原理于声透镜声场描述，反 透镜当成一种位相调制器，首次把光学中处理透镜位相调制因子概念引入声透镜声场计算中，作为声透镜对入射波前位相调制的量度，根据瑞利－索末菲衍射理论，导出了薄声透镜声场的积分表达式，并在近轴条件下，采用比菲涅耳近似更高阶的近似方法，得到了适用于计算较大孔径薄声透镜声场分布的瑞利－索末菲衍射公式，为这类声透镜的声场分析提供了理论基础。     

同尺寸弯振圆盘辐射声场指向性研究

对薄圆盘的弯曲振动和辐射声场的特性进行了研究,推导出了三种边界条件下圆盘辐射声场指向性的数值表达式,编制程序并研究其声辐射特性。结果表明,相同尺寸不同边界条件下圆盘指向性的尖锐程度不同,固定边界条件下圆盘辐射声场指向性最佳,自由边界条件下较差,并且随着圆盘模式和几何尺寸的增加各边界条件下圆盘的指向性均逐渐变差。     

音箱的布局对空间声场的影响

论述音箱的选用和布局对空间声场分布的影响。     

低频超声反应器声场的研究

利用超声波降解罗丹明B来测量自制两用式超声波反应器和超声波——环流式反应器的声场,通过测定罗丹明B降解率的变化,研究了超声波反应器和超声环流反应器空化效应,并讨论影响超声波反应器和超声环流反应器的空化效应的因素及不同条件下的声场特征.     

外面没有别人，只有你自己

美国科研人员进行过一项有趣的心理学实验,名日“伤痕实验”。 每位志愿者都被安排在没有镜子的小房间里,由好莱坞的专业化妆师在其左脸做出一道血肉模糊、触目惊心的伤痕。     

Classrooms for Children with Developmental Disabilities: Sound‐field and public address amplification systems compared

Background noise poses adverse effects on speech sounds and affects student learning, especially for children with developmental disabilities. Sound‐field and public address amplification systems can help to solve this problem by amplifying speech sounds relative to background noise. This study surveyed school classrooms for children with special needs, and compared the performance of a sound‐field and a portable public address system in classroom environments. Unoccupied room noise levels and reverberation times were measured in eight classrooms at four Hong Kong schools for children with special needs. Speech levels in each classroom were measured under three conditions: without amplification, with public address system amplification, and with sound‐field amplification. Speech‐to‐noise ratios were calculated for each condition. Noise and unamplified speech‐to‐noise ratio values exceeded recommended acoustic standards in all classrooms. When sound‐field and public address amplification systems were installed, speech‐to‐noise ratios improved considerably. When either amplification system was used, a uniform sound‐field resulted. The applicability of both types of amplification system and their relative merits in special education classrooms are discussed.     

Finite element study on impact sound transmission through a floating floor

To understand the characteristics of impact-sound transmission through a floor is very helpful for developing sound attenuation strategies to acquire a high quality of dwellings. Sound transmission through a floating floor to the room underneath was modeled by finite-element method (FEM). The sound pressure levels calculated by the FEM model on a scale of 1:4 was compared with the measured values, which demonstrate good agreement, particularly for impact sound of a relatively low frequency. The sound pressure level in a receiving room is strongly affected by the structural characteristics of both the floor and the room. The sound pressure transmitted through a clamped floor is lower than through a simply supported floor because of the larger rigidity of the clamped floor that contributes to the attenuation mechanism of stiffness. Increase in the thickness of the fiber-glass damping layer in the floor improves sound insulation. A larger room has a larger capacity to dissipate the sound pressure and thus has a lower sound pressure level. An asymmetric configuration of room avails sound attenuation because it has weaker structural and acoustic coupling than a symmetric one.     

Computer simulation model for room diffuse sound field

With the development of computer simulation technique for room acoustics, diffuse reflection is considered more and more important. In this paper, some models are developed by considering two diffuse factors in a room-diffuse reflection due to room surfaces and scattering due to objects. The surface diffusion is treated by two different methods on the basis of probability analysis or Energy Conservation Law, and the scattering among objects is simulated as a multiple random ray-tracing process. Thus the sound pressure level distribution in a diffuse sound field can be calculated more precisely and easily. Agreement between the computer simulation results and measurements shows the accuracy of the mathematical and physical model and the applicability of the computer simulation methods. These models can be used in noise control engineering, as well as in the practice of acoustical design.     

电教用房声音处理的探索与研究

电教用房的室内声音包括直达声、前期反射声和混响声。本文运用室内声学、建筑声学和电声学的理论知识,从室内混响声和最佳混响时间入手,探讨了电教用房的几何尺寸、吸声材料、吸声结构、隔声降噪等声音处理方法,并对室内音质改善提出了两种解决方法。     

“小产权房”持有主体状况的实证分析——基于4省12市的实地调查

基于4省12市实地调研中"小产权房"持有主体状况之分析,根据我国相关法律制度与访谈材料的研究结果可知,信息因素和知识因素对"小产权房"持有主体的行为选择有一定程度的影响;"小产权房"的持有行为与持有主体的家庭收入高低呈负相关性;价差因素是民众选择持有"小产权房"的主要动机;"小产权房"的持有主体对"小产权房"未来处置的期盼呈现多样化特征,且与中国当前土地制度及土地管理制度的现实和精神不完全吻合。     

房间混响时间与隔声量的测量分析实验研究

隔声测量是绿色建筑评价的重要组成部分,建筑隔声是隔绝外界噪声的重要手段之一。因此建筑和建筑构件的隔声量测量技术的完善对降低噪声污染、促进人居声环境的改善有重要意义。混响时间是室内声学最重要、最精密的客观音质评价参量,用赛宾公式表达混响时间与房间的隔声量的相关性。以环境物理实验室为研究对象,运用切断声源法,对其混响时间和隔声量进行测量。结果显示,房间的混响时间均处于0.60~0.90 s的范围,且随频率的增加先减小再增大,于中高频段达到稳定值0.8 s,然后再小幅度减小。房间的隔声能力由表观隔声量与标准化声压级差表征,两者变化趋势一致,表现为随频率增加呈递增趋势,在测量区间由15 dB增加到30 dB。     

COMPUTER SIMULATION MODEL FOR ROOM DIFFUSE SOUND FIELD

ＩＮＴＲＯＤＵＣＴＩＯＮＷｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｃｏｍｐｕｔｅｒｓｉｍｕｌａｔｉｏｎｔｅｃｈｎｉｑｕｅｆｏｒｒｏｏｍａｃｏｕｓｔｉｃｓ,ｎｅｗｍｏｄｅｌｓｈａｖｅｂｅｅｎｐｒｏｐｏｓｅｄｆｏｒｍｏｒｅｐｒｅｃｉｓｅｌｙｓｉｍｕｌａｔｉｎｇｓｏｕｎｄｆｉｅｌｄｓｔｏｒｅａｌｉｚｅａｕｒａｌｉｚａｔｉｏｎ .Ｔｈｅｃｏｍｐｕｔ ｅｒｈａｓｐｌａｙｅｄａｖｅｒｙｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｔｈｅｒｅ ｓｅａｒｃｈｏｎｓｏｕｎｄｐｒｏｐａｇａｔｉｏｎ ,ｉｎｔｈｅｐｒｅｄｉｃｔｉｏｎｏｆｒｏ…     

提高穿孔板吸声性能的实验研究

在穿孔板结构设计中，蜂窝芯夹在两层金属穿孔面板之间，主要增加了板的刚性，同时一定程度上提高了其低频吸声系数；板后吸声薄层增加了穿孔吸声板的声阻，拓宽其吸声频带宽度，提高了吸声效果。本研究通过测试穿孔板结构的吸声系数，研究了不同结构参数（主要是穿孔板的厚度、穿孔率等）及板后空腔深度对其性能的影响。实验表明，吸声薄层的加入及板后空腔的设计。使蜂窝穿孔金属吸声板具有较宽的吸声频带、理想的共振频率、较高的吸声系数，特别是对船艇机舱噪声辐射峰值具有良好的吸声效果。     

精密机械设计与制造专业群实训体系建设的创新研究——以苏州工业园区职业技术学院为例

为了能更好地服务于其对应的工作领域,精密机械设计与制造专业群实训体系在群内各专业原有实训条件和方案的基础上进行创新建设,整合所有资源,建立更具共享性的基础实训室、专门实训室、综合实训室、微公司和校外实训基地,且呈现出专业递进性,建立了技能实训的教学组织机制、"双带头人"的专业负责机制和以能力为主的评价机制。     

关于声区不统一的根源及纠正对策的探讨

声乐是研究歌唱方法的学科。不仅在理论上要坚持正确的导向,在实践训练过程中,更应把握发声的科学性,声区统一是歌声方法坚持的基本原则。旨在弄清声区划分的两种方法,分析常见的声区不统一的根源。一种是对声音在思想认识上存在错误,把声区与共鸣腔体孤立的、机械的搭配起来;另一种是由于声音技术的不成熟而导致的声区不统一。针对声区不统一存在的问题,做出相应的纠正办法,具体而言,男女声在训练声区统一的过程中,办法略有不同。