有界区域内具有非线性阻尼项可压缩欧拉方程组

运用能量估计研究了带非线性阻尼项等熵欧拉方程组在有界区域中的全局经典解的整体存在性问题。当初始数据在某一常状态附件的小扰动时,证明了经典解整体存在,并得到了该解在大时间以指数衰减的方式趋于常状态的平衡解。     

Dynamic properties of composite cemented clay

In this work,the dynamic properties of composite cemented clay under a wide range of strains were studied considering the effect of different mixing ratio and the change of confining pressures through dynamic triaxial test. A simple and practical method to estimate the dynamic elastic modulus and damping ratio is proposed in this paper and a related empirical normalized formula is also presented. The results provide useful guidelines for preliminary estimation of cement requirements to improve the dynamic properties of clays.     

浅析我国橡胶制品行业的发展现状与建议

随着改革开放的深入和社会主义市场经济体制的建立和发展,橡胶工业面临着新的挑战和机遇。近几年来,橡胶行业得到不少发展,已有细分行业稳中有升,新生橡胶细分行业则飞速发展。然而,目前我国橡胶产业与国外相比,在生产技术水平、生产规模、产品品牌、产品性能等方面都还有一定的差距。本文就当前我国橡胶制品行业的现状进行了较详细地分析,并提出了发展我国橡胶制品行业的建议。     

迷宫气封动力响应分析及减振规律研究

采用一种将柔度系数法、谐波平衡法与求解摩擦力的数值跟踪法相结合的时频转换方法,对迷宫气封结构的响应进行了计算.对阻尼套筒摩擦片沿周向和轴向的不同分布对结构减振效果的影响进行了分析,并得出相应结论.     

带有路由相关性分析的路由抖动抑制算法

域间路由协议的稳定性是十分关键的,路由抖动是域间路由不稳定的重要原因之一。在分析比较了几种路由抖动抑制（Route Flap Damping,RFD）算法的优缺点的基础上,在RFD＋算法的基础上加入了路由相关性分析和判断,使得和时间相关的抖动路由被抑制,从而减少路由更新消息数量,缩短有效路由的搜索过程。最后通过仿真实验表明了该算法能够使抖动路由配置收敛到稳定状态,并缩短了BGP的收敛时间。     

基于系统抽样技术的随机减量法

将系统抽样方法应用于随机减量法中随机振动信号的提取,对当测量得到的结构响应信号数量很大时如何能较准确地识别结构系统的周期和阻尼比问题进行了研究,给出了结构系统周期和阻尼比估计量的表达式．数值算例结果表明,当结构系统响应信号长度很大时,该方法可较好地解决信号长度与识别精度的矛盾．     

Optimized anti-vibratory system for stretched canvas artwork hanging in a museum

To prevent the deterioration of artwork on stretched canvas in a museum, it is often necessary to neutralize the transmission of vibrations from sources such as the wall or the floor. An anti-vibratory system easily optimizes vibrations that are transmitted from the floor because the artwork's motion occurs in vertical translation. Hanging artwork, which receives vibrations from the wall, presents a more complex case because the motion consists of a translation and a rotation. This paper presents a model to determine a cutting frequency above which vibrations transmitted to the artwork are lowered. A procedure to obtain the parameters of this model is also presented. Experiments in a laboratory and in the Louvre Museum validate the predicted cutting frequency given by the model. A downloadable spreadsheet is available to apply this method to specific artwork.     

具有边界阻尼的黏性波动方程解的指数衰减性

设Ω是Rn的具有光滑边界Γ=Γ0∪Γ1的星形有界区域,这里Γ0与Γ1是不相交闭集,ν为外向单位法向量。在Ω上研究具有边界阻尼项的非线性黏性波动方程。当记忆项的核h满足指数衰减性,并非线性项F满足适当的条件时,应用扰动能量的方法证明了强解和弱解的指数衰减性。     

Dynamic properties of composite cemented clay

INTRODUCTIONSoftsoilsarewidelydistributedinChinasco-astalareas.The1985earthquakethatinflictedgreatdamagetoMexicoCitysitedonsoftsoilfounda-tionsgreatlyattractedattentionofresearchersandengineersandmovedthemtostudythedynamicpropertiesofsoftsoils.Manyresearcheshavebeendedicatedtothestudyofdynamicpropertiesofsoftsoils.InChina,deepcementmixingmethodshavebeenwidelyusedinthecoastalareas.Theme-chanicalpropertiesofthesecompositefoundationsoilsarenotthesameasthatofundisturbedsoftsoilsorotherkinds…     

带有阻尼项的二阶微分方程的振动性定理

借助于一个一般的Riccati变换 ,研究了一类带有阻尼项的二阶变系数微分方程在有限区间 [a ,b] [t0 ,∞ ]上零点的存在性 .