水下吸声橡胶的性能研究

利用自制的小型声脉冲管装置研究水下吸声橡胶的声学性能。并考察几种常用配合剂及蛭石粉、玻璃微珠对橡胶吸声性能的影响。     

基于声偶极子原理修正载重轮胎噪声模型

研究载重轮胎噪声发声机理,基于声偶极子原理改进轮胎花纹噪声发声模型。由于载重轮胎花纹块击地声和离地粘吸声是噪声主要来源,考虑轮胎与路面形成喇叭筒效应及轮胎前后沿构成排偶极子效应,开发出载重轮胎噪声仿真分析及优化软件包。结果表明：改进的载重轮胎花纹噪声发声模型更合理、更精确,轮胎花纹噪声实测谱与仿真谱接近。     

Finite Element Solution for Dynamic Mechanical Parameter Influence on Underwater Sound Absorption of Polyurethane-Based Composite

Underwater noise pollution, mainly emitted by shipping and ocean infrastructure development of human activities, has produced severe environmental impacts on marine species and seabed habitats. In recent years, a polyurethane-based (PU-based) composite with excellent damping performance has been increasingly utilized as underwater sound absorption material by attaching it to equipment surfaces. As one of the key parameters of damping materials, dynamic mechanical parameters are of vital importance to evaluating the viscoelastic damping property and thus influencing the sound absorption performance. Nevertheless, lots of researchers have not checked thoroughly the relationship and the mechanism of the material dynamic mechanical parameters and its sound absorption performance. In this work, a finite element model was fabricated and verified effectively using acoustic pulse tube tests to investigate the aforementioned issues. The influence of the dynamic mechanical parameters on underwater sound absorption performance was systematically studied with the frequency domain to reveal the mechanism and the relationship between damping properties and the sound absorption of the PU-based composite. The results indicate that the internal friction of the molecular segments and the structure stiffness were the two main contributors of the PU-based composite’s consumption of sound energy, and the sound absorption peak and the sound absorption coefficient could be clearly changed by adjusting the dynamic mechanical parameters of the composite. This study will provide helpful guidance to develop the fabrication and engineering applications of the PU-based composite with outstanding underwater sound absorption performance.     

PU/EP型水声吸声材料动态模量和声学参数的实验研究

采用聚氨酯(PU)和环氧树脂(EP)及云母填料合成了PU/EP二元IPN水声吸声材料,对该材料的动态模量和声速进行了测量,研究了EP含量和云母填料及含量对材料动态模量及声速的影响,并对材料的吸声性能进行了分析。结果表明,材料弹性模量越大,材料中声波传播速度就越大;随着填料含量的增加,声速的下降幅度增大。并用直观的物理量表征了抽象的声学量,为指导水声材料的设计提供了基础。     

Underwater EIS measurements

The “on site” EIS evaluation of coatings on steel constructions immersed in water or splashed by water is much more difficult than in atmospheric conditions. There are many technical problems with insulation of electrical connections, the mounting and leak tightness of measurement cell and the exclusion of measurement of electric capacitance between the counter electrode and surrounding constructions. These problems were successfully solved by the team of scientists from Road and Bridge Institute, Atlas Sollich Electronic Systems Ltd. and Trento University. The construction of the measurement cell, the investigation method as well as some of the results from “on site” coating investigation were presented.     

青染料无银声迹将取代留银声迹(英文)

本文较详细地叙述了青染料无银声迹取代标准再显影声迹和高品红染料声迹过程中所涉及的技术和设备,包括声迹的还音、红光LED的类型以及制作声迹时声底、声正的密度确定。     

国外水下液体化学推进剂的研究现状

综述了水下液体化学推进剂的品种、性能、应用以及未来的发展方向,指出单组元液体推进剂和多组元液体推进剂因能量和安全特性较优而被广泛应用,化学储能型推进剂是未来的发展方向之一,同时建议国内应加强水下液体化学推进剂的研究.附参考文献17篇.     

一种新型吸声材料的结构设计及其吸声性能研究

以聚醚多元醇和异氰酸酯为原料,通过一步法制备了聚氨酯泡沫(PU),将PU与微穿孔板(MPP)结合起来,制备了一种新型层状吸声结构。分别研究了穿孔率、空腔深度、材质及MPP厚度对其吸声性能的影响。结果表明:所设计的新型层状吸声结构具有良好的吸声性能,所设计的吸声结构在空腔厚度为20mm时具有最佳吸声性能。     

泥土的咕咕声

混着泥土味道的咕咕声，可以唤醒人们温润的农耕记忆。下里巴人的泥玩具，在继承传统观点基础上，结合当代人的审美，依旧拥有旺盛的生命力。浚县泥塑的发展模式，值得其他非遗借鉴。     

炸药水中爆炸规律的研究进展

通过对比炸药空中爆炸的特性,阐述了水中爆炸的显著特点,分析和总结了炸药水中爆炸规律的研究现状,包括水中爆炸冲击波理论研究、气泡脉动和目标对炸药水中爆炸的动态响应等,并根据已有的研究现状,提出了目前炸药水中爆炸机理的两大类研究热点和发展培势,即应重点进行炸药水中爆炸毁伤作用及水中爆炸载荷的能量输出结构研究,深入研究目标对于炸药水中爆炸近场能量输出结构的动态响应过程。附参考文献31篇。     

环境友好型水下固化涂料的研制

以环氧树脂为基料,开发了环境友好型水下固化涂料。讨论了涂料各组分的选用原则及其对涂料性能的影响,并简单介绍了水下固化涂料的施工工艺以及实际应用情况。     

水下环氧涂料技术发展

简单介绍了采用环氧树脂的水下涂料的发展历史，目前常用的固化剂类型，以及水下环氧涂料在使用中需要注意的问题。     

健康有序发展

针对前一段媒体的不实宣传,以及发展巨型工程轮胎观念混乱的状况,为了促进我国工程轮胎产业的健康发展,中国橡胶工业协会于2007年4月13日在北京召开了“工程子午线轮胎现状及发展研讨会”,组织技术专家和工程轮胎生产企业共同对发展     

水下修复材料的研究进展

水下修复技术对水下混凝土建筑物损坏开裂的修补起到极其重要的作用,而修复材料是水下修复技术中至关重要的一环。对水下修复材料的种类、组成和特点进行概述;并对一些修复材料的应用进行介绍。     

Numerical Modeling Evaluation of Underwater Energies

The underwater detonation of explosives has been modeled using the one-dimensional code SIN. Conditions for the modeling are carefully chosen so that equilibrium product isentropes calculated with BKW equation of state can be used with enough accuracy. The characteristics of the shock wave and gas bubble pulsation are used for the evaluation of underwater energies. Values of the shock wave and bubble parameters obtained, and of the shock and bubble energies, are compared with data available from literature for both ideal and non-ideal explosives. The modeling appears to be able to predict fairly accurately the underwater energies of explosives with quasi-ideal behavior, while it overestimates energies of non-ideal compositions, particularly the shock energy.