An Acoustic Converter Used to Measure Ionizing Radiation Energy Loss

A monitor is proposed based on ultrasonic production when ionizing radiation passes through a medium. The recording element is a 0.2 mm aluminum plate mounted in a ceramic acoustic converter AC in the form of a wedge of thickness 2 mm. The low plate thickness minimizes the beam parameter distortion, while special technology used in the AC provides high sensitivity. The device has been calibrated in the proton beam from the ITEP accelerator at 200 MeV with 2·10⁹–6·10¹⁰ particles in a pulse and a pulse length of 70 nsec.     

Ultrasound‐activated Knoevenagel condensation of malononitrile with carbonylic compounds catalysed by alkaline‐doped saponites

α,β‐Unsaturated nitriles have been synthesized by Knoevenagel condensation of a carbonylic compound with malononitrile, assisted by sonochemical irradiation. Two alkaline‐promoted clays (Li⁺‐ and Cs⁺‐exchanged saponites) have been employed as catalysts. The influence of the carbonylic compound (benzaldehyde or cyclohexanone) and the use of a solvent on the catalytic activity have been studied. Remarkable increase in the conversion values has been found when the reaction is activated by ultrasound, as compared with the thermal activation. In this green, solvent‐free procedure, α,β‐unsaturated nitriles have been produced in very high yields (97%) when the Cs⁺‐saponite is used as catalyst. Copyright © 2004 Society of Chemical Industry     

Influence of the Temperature of a Body on Its Weight

The physical preconditions are considered for the temperature of a body to influence the force of gravity experienced by it. The results are given of experiments on weighing metal rods heated by ultrasound which confirm a dependence of the weight of the rods on their temperature.     

单片机在超声测距系统中的一种应用

为提高人们在测量距离时的方便性和准确性,现介绍一种基于单片机控制的超声测距系统的构成、工作原理和硬软件设计,利用该系统及其设计方法可以作为机器人的辅助视觉系统,也可用于其他的检测系统中.     

银耳多糖超声波提取工艺优化及抗BV2细胞炎症的作用研究

以银耳为原料, 采用超声波辅助热水浸提法提取银耳多糖, 以多糖提取率为指标, 以超声波功率、提取料液比、提取温度和提取时间为影响因素, 设计单因素试验, 并通过正交试验得到较佳提取工艺。通过用TRPV1(Transient Receptor Potential Vanilloid1)试剂盒检测了小胶质细胞TRPV1的释放水平, 与脂多糖(Lipopolysaccharide, LPS)对照组相比, 不同质量浓度的银耳多糖组(62.5, 250, 1000 μg/mL)均能不同程度地抑制TRPV1的释放量。说明了银耳多糖对于BV2小胶质细胞炎症具有良好的抑制作用。     

超声波处理微污染水体技术研究

考察了用超声波降解水中低浓度三氯乙腈、氯代苦味碱、溴苯的动力学，并从工程角度分析了多种污染物共存、自然水体等复杂状态下的可行性。探讨了采用空气鼓泡、不控水温的操作方式。结果表明超声波可以较快地去除复杂水体中的多种有机污染物，氧化可在批式反应器与连续流反应器中进行，高流速可以提高反应器的空间与能量利用效率。     

超声波应用于有机合成的最新进展

近年来，超声波在有机合成中的应用发展非常迅速，和传统的有机合成相比，它具有反应条件温和，操作方便，易于控制，提高产率和缩短反应的时间等优点。本文在对研究大量中外文献的基础上，综述了超声波应用于有机合成的最新进展。     

Effect of ultrasound on the morphology and properties of polypropylene/inorganic filler composites

The effects of ultrasonic irradiation on the rheology, structure, and properties of PP/inorganic filler composites were studied. Scanning electron microscopy showed that ultrasound increased the orientation degrees of acicular fillers to the flow direction. WAXD indicated that ultrasound vibration induced sheet fillers orient with its surface perpendicular to the direction of the ultrasound vibration. The orderly rearrangements of fillers in the polymer melt induced by ultrasound vibration can reduce the steric hindrances in the flow field and increase the flowability of the PP/inorganic filler composites. The effect of ultrasound on reducing the apparent viscosities is very prominent, especially at lower shear rate. Ultrasound has an even more marked effect on reducing the apparent viscosities of composites containing fillers of larger size. With ultrasound vibration, the mechanical properties of the composites are also improved because of the orientation and uniform dispersion of fillers in the matrix. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1553–1560, 2005     

响应面法优化管萼山豆根总生物碱提取工艺

采用微波控温辅助超声波的方法提取管萼山豆根茎中总生物碱,通过单因素法和响应面法优化了提取工艺,考察了管萼山豆根茎中总生物碱对1, 1-二苯基-2-三硝基苯肼自由基(DPPH·)、2, 2-联氮-二-3-乙基-苯并噻唑-6-磺酸自由基(ABTS·)和超氧阴离子自由基(O2?·)的清除作用。结果表明,模型优化并修正的最佳工艺条件为:提取时间37.8 min,微波加热温度64.5℃,超声功率575 W,乙醇体积分数95%,在该条件下总生物碱得率为0.5418%,高于不采用微波超声辅助的0.2436%、超声辅助的0.4538%、乙醇回流的0.3884%。管萼山豆根茎中总生物碱在DPPH·、ABTS·、邻苯三酚浓度分别为0.1、7.0、8.0 mmol/L条件下,其半数抑制质量浓度(IC50)分别为0.891、0.552和0.390 g/L。     

管材超声波分层缺陷检测中盲区的构成探析

管材超声波分层检测作为控制产品质量的关键步骤,必须引起相关从业人员的重视,特别是要重点分析分层缺陷检测中盲区的构成原因和分布特征。只有这样,才能切实保证检测结果的准确性,更好地控制管材质量。通过对超声波分层缺陷检测的重要性进行阐释,分析了其中盲区的构成和分布等问题。