基于MSP430G2553超声波测距仪的设计

本设计是一种基于MSP430G2553单片机的超声波测距仪,电路采用模块化设计,发射模块发出超声波,探测到障碍物后反射超声波信号,接收模块接收并交给单片机进行处理,最终结合温度传感器采用时差法计算出往返距离。     

金属中激光超声的产生及应用

介绍了用不同脉宽、不同波长的钇铝石榴石(Nd:YAG)激光在不同厚度的金属样品中产生超声脉冲的实验。超声波的接收是用聚偏氟乙烯薄膜(PVDF)实现的。文中给出了激光超声脉冲及其在金属板中的回波的波形曲线;测量了不同条件下激光超声幅度与激光能量的关系,超声幅度与激光波长的关系,以及超声脉宽和激光脉宽的关系;观察到了激光超声的传播方向总是沿被照表面的法线方向,而与激光的入射角无关。实验结果表明,激光超声作为一种非接触的超声源,对于工业应用尤其是高温运动状态下对弯曲表面的工件(如管材等)进行厚度测量和探伤具有广阔的应用前景,也将是激光与物质相互作用领域的一种重要研究手段。     

超声波测距系统

本文介绍了一种基于单片机的脉冲反射式超声测距系统。该系统以空气中超声波的传播速度为确定条件,利用反射超声波测量待测距离,并且描述了系统研制的理论基础。文章概述了超声检测的发展及基本原理,介绍超声传感器的原理及特性,并且在介绍超声测距系统的基础上,提出了系统的总体构成。     

相控阵技术在水下超声成像中的应用初探

讨论了水下超声成像技术研究的必要性，分析了国内外目前水下航行器中声呐的发展现状，并对相控阵技术及其适用于水下超声成像的发展状况进行了研究，展望了水下超声相控成像技术的发展趋势。还提出了相控阵超声成像的系统构成以及其中应用的关键技术指标，为水下超声成像的研究奠定了理论基础。     

基于PICmicro系列单片机的超声波测距仪设计

利用微处理机控制单元（MCU microprocessor control unit）控制的超声波测距仪系统,由PIC16F877单片机、超声波发射电路、超声波接收放大电路及显示电路组成。通过MCU控制时间计数,计算超声波自发射至接收的往返时间,从而得到实测距离。此系统具有易控制、工作可靠、测距准确度高和流程清晰等优点。     

医用超声雾化器改进措施探讨

近年来,随着超声技术的发展,超声雾化器在疾病治疗方面得到了广泛应用,超声雾化器已成为临床最常用的医疗仪器之一。本文叙述了医用超声雾化器的工作原理以及在实际应用中遇到的问题和改进措施。     

Ultrasonic delay lines

This paper deals with the experimental aspects of ultrasonic delay lines in liquid media and is a sequel to a previous paper treating the general theory of such devices.Delay devices employing ultrasonic propagation through liquids have proved satisfactory for delay times of the order of 3 milliseconds or less. Such devices can be made broadband and give excellent reproduction of pulse shape. The design considerations for such devices are discussed and illustrated by actual examples.     

磁场和超声波对污水的联合净化作用

开发污染治理技术是当前国内外水处理领域的研究热点。磁场、超声波单独对污水处理的研究已经较多。首先分别介绍了磁分离和超声波水处理的原理,总结了各自的影响因素,然后探讨了两者强相互作用下对污水的效应,提出了处理污水的新方法,具有广阔的应用前景。     

超声波对醋酸乙烯乳液（VAC）聚合的影响（英文）

对比了醋酸乙烯（VAC）在传统聚合中和超声波辅助聚合中的单体转化率和乳液粒径分布的差别。在VAC聚合过程中外加超声波环境，单体转化率从92.5 %提高到98.8%，乳液粒子平均粒径从136.7nm减小到101.4nm。在超声波辅助VAC乳液聚合中，研究了引发剂浓度和反应温度对单体转化率及乳液粒径分布的影响。试验结果表明仅靠超声波产生的自由基不足以引发聚合反应，引发剂分解产生的自由基在引发聚合过程中起着重要的作用。简单介绍了超声波辅助乳液聚合的机理，超声波可以连续提供自由基，而这些自由基的作用是使死聚合物链变的有活性，导致单体具有较高的转化率。     

Female frogs send ultrasonic signals for courtship

During their studies of Odorrana tormota, a frog species with recessed tympanic membranes, CAS researchers have found that females go ultrasonic during courtship, revealing an amazingly system for communication. The work was reported online on 8 May by Nature.     

浅谈带节流圈的小径管焊缝超声波探伤方法

本文是针对某电厂1#机组低温再热器联箱短接管焊缝加节流圈的焊缝,因其特殊结构,不能进行射线探伤检验,而采用超声波方法进行检验,通过实践证明这种方法是有效可行的。     

基于SVM的实时自动超声钢轨伤损检测分类系统

介绍了一个更有效的基于支持向量机的实时超声波钢轨伤损自动检测分类系统.根据钢轨伤损的特点提取特征量,利用基于支持向量机的分类预测算法实现钢轨伤损的实时检测分类,并基于统计处理的计算伤损尺寸.在嵌入式系统DSP中利用该机器学习算法实现了伤损的实时处理和测试.实现了钢轨伤损实时报警、显示伤损类型、所处轨内位置及程度.     

一种超声流量计的设计

本文采用时差法设计了一种超声流量计,用于测量气体的体积流量,避免了接触式流量计寿命短、安装不方便等缺点。该设计精度高,抗干扰能力强,具有广阔的应用前景。     

Optimizing the use of ultrasound to deliver chemotherapeutic agents to cancer cells from polymeric micelles

In this study, we present an artificial neural network (ANN) model that attempts to predict the dynamic release of doxorubicin (Dox) from P105 micelles under different ultrasonic power densities at 20 kHz. The goal is to utilize the developed ANN model in optimizing the ultrasound application to achieve a target drug release at the tumor site by controlling power density and ultrasound duration via an ANN-based model predictive control. The parameters of the controller are then tuned to achieve good reference signal tracking.     

Unlike birds,bats might use a different magnetic compass to navigate

Bats, the only mammals known to possess the real ability to fly, have fascinated zoologists for a long time with their long-distance migration. How do they find their way home from an altitude of kilometers above sea level, where their stunt of ultrasonic echolocation does not work？ Recent discoveries supported the theory that bats might be able to use magnetic clues to figure out their own position,just like what birds do. However, the latest results from a joint study by a group of researchers from the CAS, East China Normal University and University of Auckland reveal that bats apply an interesting strategy different from the one underlying birds＇ orientation technique, though they both are believed to derive information about their position from the subtle changes in the magnetic field of the Earth.     

Contrast agent-free sonoporation: The use of an ultrasonic standing wave microfluidic system for the delivery of pharmaceutical agents

Sonoporation is a useful biophysical mechanism for facilitating the transmembrane delivery of therapeutic agents from the extracellular to the intracellular milieu. Conventionally, sonoporation is carried out in the presence of ultrasound contrast agents, which are known to greatly enhance transient poration of biological cell membranes. However, in vivo contrast agents have been observed to induce capillary rupture and haemorrhage due to endothelial cell damage and to greatly increase the potential for cell lysis in vitro. Here, we demonstrate sonoporation of cardiac myoblasts in the absence of contrast agent (CA-free sonoporation) using a low-cost ultrasound-microfluidic device. Within this device an ultrasonic standing wave was generated, allowing control over the position of the cells and the strength of the acoustic radiation forces. Real-time single-cell analysis and retrospective post-sonication analysis of insonated cardiac myoblasts showed that CA-free sonoporation induced transmembrane transfer of fluorescent probes (CMFDA and FITC-dextran) and that different mechanisms potentially contribute to membrane poration in the presence of an ultrasonic wave. Additionally, to the best of our knowledge, we have shown for the first time that sonoporation induces increased cell cytotoxicity as a consequence of CA-free ultrasound-facilitated uptake of pharmaceutical agents (doxorubicin, luteolin, and apigenin). The US-microfluidic device designed here provides an in vitro alternative to expensive and controversial in vivo models used for early stage drug discovery, and drug delivery programs and toxicity measurements.     

清洁机器人的自动避障控制系统

本文介绍了基于全区域覆盖思想的清洁机器人自动避障行走控制系统的硬件电路设计和软件设计。根据超声波开关模块检测的障碍物信息,通过单片机把检测到的障碍物信息转化成控制信息,由步进电机带动两个驱动轮旋转,并结合旋转编码器的使用,实现清洁机器人的自动避障行走。     

超声表面波检测的局部频域特征分析方法初探

在自行构建的超声频谱分析系统上,研究表面缺陷对声波调制的声学机理,提出一种基于单缺陷回波的局部频谱分析而对表面缺陷类型进行检测的方法,给出了用超声频域分析法对工件表面缺陷特征分析的实例,并用计算机检测系统得出了相应的试验结果,从而提高了检测可靠性.此检测方法可成为计算机辅助对缺陷进行分析的依据.     

桂西地区不同产地八角茴香莽草酸的含量测定

文章优化了八角茴香莽草酸的提取方法。分别考察了单因素料液比、超声波功率、提取温度、提取时间的影响,并在单因素基础上进行了4因素3水平正交设计试验,得到最佳提取工艺为:料液比:1∶28(g:mL),超声波功率190W,提取时间20 min,提取温度53℃。在最优工艺下分别测定了桂西地区不同地方八角茴香莽草酸含量,结果表明大新的样品含量最高,达到8.21%,隆林的样品含量最低为5.87%。     

超声波辅助提取草珊瑚中反丁烯二酸工艺研究

针对草珊瑚（三明）中反丁烯二酸的提取工艺的研究,采用超声波法进行优选,用液相色谱法（测量条件：Agilent 1200C18（250mm×4.6mm,5μm）色谱柱,流动相为乙腈-0.1%磷酸溶液,比例为（2：98）,流速为1.0mL/min,柱温30℃,检测波长208nm,出峰时间为1.471min）测定不同条件下样品的吸收峰,以吸收峰大小为指标定性分析从而确立单因素设计正交实验,通过正交实验研究5因素（溶剂浓度、pH、超声波功率、超声波温度、料液比）对草珊瑚中反丁烯二酸的提取效果的影响。通过正交实验最终确立了最优提取工艺：溶剂浓度70%;pH=4;超声波功率50w;超声温度50℃;料液比1：35,提取时间为40min。通过该实验确立最优工艺提取效果好,简便易行。