Terfenol-D球形低频换能器

本文设计并制作了一种Terfenol—D球形换能器,使用有限元分析软件ANSYS对换能器的电声参数进行模拟计算,计算结果与实验结果符合很好。换能器水中谐振频率f=6.3kHz,Q-3dB=2.63,证明具有低频、宽带的特点。     

Synthesis of Ionic Liquids Using Non Conventional Activation Methods: An Overview

Summary. The synthesis of ionic liquids under non conventional activation methods is historically reviewed and completed with the recent developments of “one-pot” synthesis and combination of these activation methods.     

影响DAS精度的几种因素

在基于数据采集的DAS中，从设计角度出发，详细地分析了系统的传感器，预处理电路，噪声，采样频率和干扰系统精度的影响。     

用于电力系统的光学电流互感器技术进展

介绍了光学电流测量技术的发展情况，描述了目前几种主要的互感器结构及其基本原理，并对各自存在的问题及解决途径进行了讨论。从研究现状来看，块状玻璃型传感器技术相对成熟，已经有商业产品问世；混合型传感器测量精度较高，但传感头有源电路的供电技术复杂，还没有圆满的解决方案；全光纤型是光学电流互感器发展的最终目标，目前存在的主要问题是光纤的固有线性双折射难以处理，有赖于新型光纤材料及集成光学元件的进一步发展。最后综合评述了光学电流互感器技术的发展趋势及产业化前景。     

A Facile Synthesis of Aldehyde and Ketone via Senochemical Barbier Reaction and Oxidation

Methyl ketone is prepared by a sonochemical Barbier reaction of methyl iodide, magnesium powder and aldehyde in Benzene/THF (9/1) solvent in a commercial ultrasonic cleaning bath (39 kHz), followed by the addition of N-chlorosuccinimide (NCS) as an oxidizing agent.     

Miniaturized back-side contact transducer for potentiometric sensors

A novel type of a miniature transducer for potentiometric sensors was designed and tested. The transducer is made from an ordinary printed circuit board using a typical technology. As a result, a back-side contact structure was obtained, which can be mounted in flow systems. The advantage of the fabrication process is its cheapness and flexibility in designing modified structures. The measurement properties of the transducer were tested as a chloride sensor. Then the structure was covered with polyHEMA and a potassium-selective membrane and tested as a potassium sensor. The performance and the long-term stability of the sensors with plasticized PVC and Siloprene based potassium-selective membranes were compared.     

Phosphine-free Suzuki cross-coupling reactions under ultrasound

Suzuki cross-coupling reaction was successfully carried out in ethylene glycol under phosphine-free conditions to obtention of biaryls using ultrasonic irradiation. High yields were obtained using different palladium and bases sources. The catalyst was recycled up to three times with good to moderate activity.     

宽带宽波束纵向水声换能器研究

本文通过设计纵向水声换能器辐射头的形状及利用其弯曲振动模,实现宽带宽波束辐射特性,采用后质量块的嵌套结构有效缩小了换能器的长度。利用ANSYS有限元软件模拟了小型宽带宽波束纵向水声换能器的电声特性。研制了换能器样品,实现了与有限元模拟计算结果相一致的电声参数:谐振频率14kHz,最大发射电压响应141．9dB,-3dB带宽为11．3～18．7kHz,-3dB带通Q值为1．9,在14kHz频率下波束宽度为132°,比通常纵向换能器波束宽度宽23％。     

DECOMPOSITION OF BLACK LIQUOR BY ULTRASOUND PROCESS

1. INTRODUCTION Ultrasonic irradiation has been shown to be effective in the destruction of aqueous organic contaminants. In sonolysis, the liquid is irradiated with sound waves generated from an ultrasonic source. These sound waves create cavities due to oscillating pressures in the liquid medium. The dissolved gases and vapors in the bulk solution can diffuse into these cavities. The cavities increase in size and implode, generating temperature of about 5200…     

A thermodynamic study of two anionic amphiphilic penicillins in aqueous solution by ultrasound speed measurements

The critical concentrations of sodium cloxacillin and sodium dicloxacillin penicillins in aqueous solution were determined over the temperature range 288.15–313.15 K by a method based on deconvolution into Gaussians of the second derivative of the measured ultrasound velocity. The mass action model was used to calculate the thermodynamic standard quantities: free Gibbs energy, enthalpy and entropy of aggregate formation. The results are discussed in terms of the structure of the drug aggregates.