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五氯苯酚降解的超声诱导 总被引:10,自引:0,他引:10
人为或自然因素会导致挥发性或不挥发有毒有机物存在于饮用水中,这一现象 已成为国际上共同关心的问题。从长期对健康状况来说,即使不能辨别饮用水中的 味道和气味,但只要有十亿分之几毫克的有毒有机物存在,就足以使水不能饮用。 所以,废水处理刻不容缓。同废水处理相关的实验方法中,超声作为一种处理方法 ,早有报道,因为超声化学效应主要是空化,空化是自由基,特别是羟基自由基产 生的根源,而痉基自由基是强烈而非特殊的氧化物,它能迅速同水中化合物发生反 应。作者以五氯苯酚为模拟水样,分别用低频(16 kHz)和高频[(800 ± 1) kHz]以及其组合进行超声降解研究。研究表明复频降解效果最好,最差为低频。在 Fenton类试剂存在下,与Fenton类单独降解效果相比,复频则是它的20.93倍,高 频是它的4.9倍,低频与它几乎无变化。实验表明,频率组合对有机污染物的降解 是一条有效途径,但需要更进一步的研究。 相似文献
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Nearfield acoustical holography is a powerful tool for imaging of acoustic sources. In this article, the basic theory treating steady-state acoustic radiation with generalized holography has been discussed. By holographic imaging, the vibration characteristics of irregular objects, the Chinese ancient musical instrument, the one-tone chime stone and the two-tone chime stone provided by the Institute of Archaeology, the Museum of Hubei Province, have been researched. The results show that the ancient chime stone has two main vibration modes, which make up the base of sound produced by the instrument. As for the two-tone chime stone, it is not so long and wide as the single-tone chime stone, but thicker and smoother than the single-tone chime stone. When it is excited at different positions, although it radiates sounds of different frequencies, its vibration modes are similar. This may be related to its dimensions and shape. The research is helpful for studying the sound producing system and the radiated field characteristics of the chime stone. 相似文献
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提高声全息成像分辨率的有限频谱重建法 总被引:2,自引:0,他引:2
本文提出用脉冲波声全息提高成像分辨率(特别是纵向分辨率)的新方法。理论分析及模拟计算表明,利用脉冲信号的有限谱分析及成像系统对有限谱的响应,脉冲波的全息重建比连续波具有较高的分辨率。在此基础上,利用重建波相位识别及解卷技术,能进一步提高其分辨率。 相似文献
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Detection and Location of a Target in Layered Media without Prior Knowledge of Medium Parameters 下载免费PDF全文
Without prior knowledge of medium parameters, a method is proposed to detect and locate a target in layered media. Experiments were carried out for liquid/liquid and solid/liquid layered media, and the location of a target in them was obtained using three methods combined, i.e., the least-square method, the method of finding minimum dispersal degree of target distribution, and the snapshot time reversal and reverse time migration mixed method. The medium parameters, i.e., the acoustic velocities... 相似文献
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编磬振动特性的声全息研究 总被引:9,自引:1,他引:8
阐述了广义声全息成像的基本原理,对其中声源与其声场的变换关系进行了必要的推导与分析.运用这一原理及自制实验系统,对湖北省博物馆提供的单音磐及双音磐的振动特性进行了实验研究.首次获得单音磐的基频、谐频振模以及双音磬在不同敲击点激励时的两个基频振模.这对进一步研究磐的发声规律及声场特性具有重要意义. 相似文献
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