共查询到19条相似文献,搜索用时 78 毫秒
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EASE4.1中AURA程序模块可运算ISO3382标准所涉及到的室内声学参量和房间脉冲响应。在预测房间音质参量及实现可听化方面,使EASE模拟水平有较大的提升。 相似文献
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为了利用计算机对室内指向性声源的声场进行模拟,文中将声线跟踪法,虚源法和Monte Carlo法相结合,编制了一种场场数值模拟仿真程序,该程序能模拟有(或无)指向性声源在室内给定点的声压级等参数值,还能计算出该点的脉冲响应函数,作为例子,分别利用该法和声压叠加法研究了点源和偶极子声源的指向性。 相似文献
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利用数字技术实现声场可听化是建筑声学领域近年来正蓬勃发展的一个研究热点。利用它来进行噪声预测与评价是噪声控制领域的新课题。本文主要论述了利用声场可听化技术进行噪声预测和噪声控制技术评价的基本原理,并简要介绍了该技术的现状及未来。 相似文献
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随着数字技术的不断发展,也必然走进广播录、扩音设备当中。数字音响设备的使用让听众欣赏到声音清晰、音质饱满,具有可听度的节目。从事录音与调音的音响工作者,不仅要从理论上了解每个设备的录放、扩音应用范围和性能,还要掌握调音台、功放以及均衡、压缩、混响等周边设备的调整和系统的联调方法,以便更好地提高系统再现声音的质量。要想掌握录音的重放技术必须重视以下三个问题。声源的特性声源可分为媒体声源和自然声源。媒体声源如CD、LD、VCD、磁带及其它线路信号输入的各种声源。自然声源则是由人声、乐器声、模拟声、大自然声以… 相似文献
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理想的声学缩尺模型测试用小型无指向性声源,需要具备以下条件:足够小的线度、无指向性辐射、较为平直的高频频率响应以及足够高的测试信噪比,并且能稳定地重复发出受控信号。设计制作了两种线度小于15 mm的小型无指向性声源:导管式点声源和六面体声源,并在简易消声室内测试了其各自的指向性与高频频率响应。测试结果表明,对于1:10的缩尺比例,两种小型无指向性声源的测试信噪比都能达到35 dB以上,无指向性辐射均满足《JJF 1468-2014无指向性声源校准规范》要求。导管式点声源的高频频率响应更为平直,但小型六面体声源在额定功率下具有更高的信噪比。两种声源均可用于建筑声学缩尺模型试验。 相似文献
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本文介绍一种封闭声场视听一体化仿真系统的原理与功能,并通过算例说明了该系统在噪声控制中的具体应用。 相似文献
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文章对室内声场计算机模拟方法和Odeon软件的功能、算法及特点做了简要介绍,并对其在厅堂音质方面的应用进行了阐述。由于不断的发展和完善,声场计算机模拟技术已成为声学设计的一项可靠而高效的工具。 相似文献
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《International journal for numerical methods in engineering》2018,113(9):1488-1506
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method. 相似文献
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Standards are the basis for production enterprises to organize production ex-factory inspection trade 《中国标准化(英文版)》2008,25(1):24-25
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.…… 相似文献
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A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa. 相似文献
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On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.…… 相似文献
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Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß. 相似文献