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 共查询到19条相似文献,搜索用时 78 毫秒
1.
巴山灵 《应用声学》2003,22(4):20-20
2003年2月27日由国家药品监督管理局医疗器械司委托全国医用电器标准化技术委员会组织,在上海市举行了SJTU-1型医用超声设备声输出测量系统的技术成果鉴定会。由王威琪院士、冯若教授、张德俊教授为主任委员的鉴定委员会,对此项成果进行了测试和技术鉴定,认为SJTU-1型医用超声设备声输出测量系统的技术指标达到了同类系统的国际先进水平,某些功能优于国外同类系统。  相似文献   

2.
冯若 《应用声学》2003,22(3):16-16
国家药品监督管理局委托全国医用电器标准化技术委员会,于2003年2月27日主持对上海市医疗器械检验所委托上海交通大学研制的SJTU-1型医用超声设备声输出测量系统,进行了技术鉴定。鉴定会委员审阅了全部有关资料、认真听取了研制组负责人寿文德教授所作的研制报告和测试组提供的测试报告,并现场参观了该测量系统的实际操作与测量。通过认真讨论,取得如下一致鉴定意见。 1 SJTU-1型声输出测量系统的研制成功,对于贯彻超声诊断设备声输出的国家标准(与国际标准同)具有重要意义。  相似文献   

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4.
医用超声测量用PVDF探针形高频微型水听器的研制   总被引:3,自引:0,他引:3       下载免费PDF全文
寿文德  钱德初 《应用声学》1996,15(5):24-26,40
本文叙述了用于医学超声测量的两种PVDF探针形高频微型水听器的设计特点,结构和它们的性能测量结果,最后介绍在非线性声学研究中的应用实例。  相似文献   

5.
超声是频率高于20 000Hz的声波,由于它遇到障碍物能发生反射、透射,同时具有方向性好、穿透能力强等特征,很快在医学诊断中得到重要应用.本文着重阐述如何利用超声在人体各种组织内的传播特性不同而形成影像,对病理作出诊断提供依据。  相似文献   

6.
检测超声换能器的性能是设计制造者和使用者都十分关心的问题。本文就超声换能器的几个主要整体性能——灵敏度、时间响应(传输函数)、空间响应(指向性和声场分布)以及等效电阻抗的测量与校准技术做了简要的综述。以灵敏度和时间响应为重点,介绍了各种校准和测量方法的原理及适用范围,并对其特点和局限性做了分析。  相似文献   

7.
寿文德 《应用声学》1994,12(5):4-10
本文概述了B型超声诊断仪声场特性的基本测量和计算方法,提出了一系列典型声压波形的瞬时声压平方函数的时间积分解析表达式,可用来近似计算脉冲声强积分和各种脉冲声强参数.对三种典型超声诊断仪的输出声压波形函数,分别进行数值积分和解析计算,两者的计算结果偏离值均小于±7.0%,表明利用这些公式可使测量过程中的数据采集和计算程序大为简化,在实际应用中具有推广价值.  相似文献   

8.
复频聚焦超声换能器水中焦区商场特性的研究   总被引:1,自引:0,他引:1       下载免费PDF全文
石焕文  尚志远  王三德 《应用声学》2001,20(4):27-30,20
本文对新研制的一种复频聚焦超声换能器的辐射声场进行了实验研究,测定了辐射压在轴向上的分布曲线,进而确定了焦区位置,这与理论所得结果符合较好,测定了辐射声压在焦平面上的分布曲线,并对焦区声场进行了定位,最后对换能器在水中焦区辐射声的频谱进行了研究,不仅观测到了两个源波,而且还观测到了和频波,差频波以及倍频波,证实了声散射声效应的存在。  相似文献   

9.
水声测量用声脉冲瞬态抑制方法的研究   总被引:2,自引:0,他引:2       下载免费PDF全文
陈毅  袁文俊  赵涵 《应用声学》2002,21(4):10-15,48
脉冲声技术是一种很常用的水声测量技术,但由于脉冲声存在着瞬态过程,严重影响了它在低频下的使用,本文中研究的水声测量用声脉冲瞬态抑制方法,通过瞬态抑制等效消除换能器的瞬态过程,从而为在有限尺寸水域内扩展水声测量低频限创造了条件。  相似文献   

10.
本文叙述了医用超声功率的常规测量方法的原理和已达到的水平之后,讨论了医用超声场的声强的使用范围和安全性问题,着重阐明了使用PVDF压电薄膜水听器扫描超声场,记录脉冲超声场的声压波形分布并计算I_(SPTP)、I_(SPTA)、I_(SATA)和I_(SAPA)的方法。给出了计算公式和实验结果,并对A型和B型超声诊断仪的典型测量数据和声强分布特征进行了讨论与比较。  相似文献   

11.
A simple and straight forward method for acoustic impedance measurement is presented and evaluated. In this method a speaker is used as the signal source. The relationship between the electrical impedance of the speaker and its acoustical load is developed and studied. It is shown that the electrical current and voltage of the speaker relate to the acoustical pressure and volume velocity. The mechanical and acoustical impedances are therefore easily derived by measuring the electrical current and voltage of the circuit. The proposed method yield itself to the automatic computer measurement and can be used for the field and in situ measurements.Comparison of the measurement data with those from other methods proves the applicability and accuracy of the proposed method.  相似文献   

12.
B. Breyer  B. Devčić 《Ultrasonics》1984,22(6):282-284
Ultrasound of time average acoustic intensities between 0.5 and 3 W cm−2 is widely used in physiotherapy. A simple device for semiquantitative checking of output power and beam shape has been designed. The beam tester consists of an absorbing plate and a sheath liquid crystal thermometer for temperature distribution display.1 The ultrasonic beam is fed to the absorber through a simple water tank.  相似文献   

13.
林书玉 《应用声学》2000,19(4):31-34
本文提出了一种测量功率超声振动系统中振动速度比的简单方法。与传统的测量方法相比,本方法将力学量转变为电学量的测量,将绝对测量变成了相对测量,降低了对实验设备的要求,有利于提高测试精度。  相似文献   

14.
水下材料声学性能宽频段测量方法   总被引:1,自引:1,他引:1       下载免费PDF全文
本文根据脉冲法和传递函数法的测试原理,建立水下声学材料吸声性能宽频段测量方法,在同一水声声管,相同状态下,对橡胶材料吸声性能进行测试分析。分析表明:常压及加压环境下,采用传递函数法和脉冲法测量材料的吸声性能,在重合频段(4 kHz~5.5 kHz)测试结果基本一致,测试偏差小于5%,从而验证了不同测量原理,测试材料水下声学性能的通用性。因此,采用传递函数法和脉冲法,可以实现水下材料声学性能宽频带测试。  相似文献   

15.
应崇福 《应用声学》2006,25(6):380-383
对超声复合振动系统中的“局部共振”现象,基于熟知的棒或管中声波产生和传播的理论,提出一种机理解释。  相似文献   

16.
With the reduction of crude oil throughout the world, enhance oil recovery technology has become a major oil research topics, which can greatly increase the recovery ratio of the crude oil before the dawning of renewable energy era. Near-well ultrasonic processing technology, as one new method, has attracted more attention for Enhanced Oil Recovery due to its low cost, good applicability and no environmental pollution in recent rears. There are two important relevant aspects about Near-well ultrasonic processing technology: (a) how to enhance the oil flow through the rocks into the pumping pool and (b) how to reduce the oil viscosity so that it can be easier to pump. Therefore, how to design a high-power ultrasonic equipment with excellent performance is crucial for Near-well ultrasonic processing technology. In this paper, recent new high-power ultrasonic transducers for Near-well ultrasonic processing technology are summarized. Each field application of them are also given. The purpose of this paper is to provide reference for the further development of Near-well ultrasonic processing technology.With the reduction of crude oil throughout the world, enhance oil recovery technology has become a major oil research topics, which can greatly increase the recovery ratio of the crude oil before the dawning of renewable energy era. Near-well ultrasonic processing technology, as one new method, has attracted more attention for Enhanced Oil Recovery due to its low cost, good applicability and no environmental pollution in recent rears. There are two important relevant aspects about Near-well ultrasonic processing technology: (a) how to enhance the oil flow through the rocks into the pumping pool and (b) how to reduce the oil viscosity so that it can be easier to pump. Therefore, how to design a high-power ultrasonic equipment with excellent performance is crucial for Near-well ultrasonic processing technology. In this paper, recent new high-power ultrasonic transducers for Near-well ultrasonic processing technology are summarized. Each field application of them are also given. The purpose of this paper is to provide reference for the further development of Near-well ultrasonic processing technology  相似文献   

17.
This paper presents the novel use of a sonochemical reaction product as a sensing material in self-powered ultrasonic reactor devices for determination of ultrasound parameters. A piezoelectric nanogenerator was fabricated via sonochemical synthesis of SbSeI nanowires compressed into a bulk sample. The prepared device was used to develop two fast and simple evaluation methods for acoustic power in liquid. A calibration procedure was carried out for both methods using a VCX-750 ultrasonic processor. The ultrasound acoustic power was varied within a 150 W to 750 W range and the corresponding nanogenerator electrical responses were measured. The voltage signals of the first method fit the best with theoretical dependence. The second technique was based on the application of the Fast Fourier Transform (FFT) to the measured electric output. The results of these two approaches were convergent. Acoustic power values of 255(8) W and 222(7) W were determined for the Sonic-6 reactor using theoretical dependence fitting to experimental data and FFT analysis, respectively. Developed sensing technology possesses great potential for sonochemistry applications.  相似文献   

18.
张海澜 《应用声学》2012,31(2):81-85
便携式超声诊断仪是近年来快速发展的新方向,它的出现和推广将改进医疗保健的质量,降低费用,可能给整个医疗事业带来新的变化。  相似文献   

19.
Laux D  Ferrandis JY  Leveque G  Gatt JM 《Ultrasonics》2006,45(1-4):104-112
The macroscopic elastic properties of two composites (Duralumin/air and Duralumin/tungsten carbide (WC)) have been calculated using periodical homogenisation methods and the elastic properties of each phase (measured by high frequency acoustic microscopy). In order to check the validity of such an approach, acoustical resonant spectroscopy has also been applied. Thanks to the comparison between the resonant frequencies predicted and measured, two major conclusions have been obtained: the homogenisation method is very accurate for the composite Duralumin/air, but not for the Duralumin/WC sample: the experimental results are not in very good agreement with the simulation. This result can be then explained by the major role of interfacial state between Duralumin and tungsten carbide.  相似文献   

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