新型隔振（缓冲）器—液力空气弹簧的动态性能特点研究及其 …

本文基于液力空气弹簧隔振器动态性能的大量冲击实验数据。阐明了该种隔振器的性能特点，并探讨了改进其动态特性的方法与思路，为这一新型隔振器的产品化和实用化提供了必要的实验研究与分析基础。     

隔振泡沫塑料的试验建模

对一种增强泡沫塑料隔振器进行试验数学建模。在分析隔振器振动试验数据和研究结果的基础上，根据位移-恢复力滞回曲线对应速度大于零和速度小于零的情况，把回线分解为上下两条。利用隔振器性质相同、安装几何对称条件、上下两条恢复力曲线关于位移反对称的特性，用幂函数多项式，按最小二乘的原理拟合代表试验数据的上下两条恢复力曲线，并经数学变换，把恢复力分解成非线性非滞回弹性恢复力和滞回非线性阻尼力两部分。研究结果表明，这一思路和方法是可行的。研究为这类隔振器数学模型建立提供了有效手段，为恢复力的参数识别提供了极大的方便，也为隔振器动力设计及动力优化奠定了良好基础。     

双层高阻尼隔振器动力学特性研究

提出一种由正负刚度元件组成的双层高阻尼隔振器,并建立其系统动力学模型.分别采用拉氏变换给出其频响特性和力传递率,利用四阶龙格-库塔法得到其时域响应.通过与单层/双层参考线性隔振器和单层高阻尼隔振器的动力学特性对比,双层高阻尼隔振器可以在中低频段较宽范围内实现振动响应的有效控制,且对多频激励的控制效果最优.文中重点关注了高阻尼隔振器设计参数刚度比α和安全系数ε对其响应特性的影响.计算结果表明:参数选择合适,可实现高阻尼隔振器无谐振峰的振动控制效果.      

金属丝网减振器静动态特性试验分析

根据金属丝网减振器非线性理论,分别从微观和宏观的角度阐述其工作机理;并为此设计出针对军用装甲车辆大功率柴油机的减振器结构。通过静、动态特性试验来分析金属丝网减振器滞迟现象:非线性渐硬、频响跳跃、谐振峰漂移等,将滞迟记忆恢复力分别进行Fourier级数展开和线性等效,从理论层面分析、推导与验证上述试验现象,由此推断出激振幅值和频率对滞迟回线形状的影响规律;并通过试验得到验证,从而为以后进行金属丝网减振器非线性建模和响应计算等理论研究提供基本的试验方案和思路指导。     

环形金属橡胶隔振器系统建模与实验研究

以航空发动机导线插头支座用环形金属橡胶隔振器的具体需求为背景,对环形金属橡胶隔振器进行了建模与实验研究.借助于动力学原理和迟滞理论,建立了隔振器的振动系统模型,并对模型中的参数进行了讨论,得出环形金属橡胶隔振器的动态频响特性.利用静态实验对不同初始变形时环形隔振器的局部刚度特性进行了分析,并通过动态实验对环形隔振器的动态频响特性进行了验证.结果表明,该隔振器具有独特的刚度和阻尼特性,其初始变形对隔振器固有频率和传递率具有较大影响.图7,表1,参11.     

金属橡胶隔振器的非线性响应特性研究

金属橡胶隔振器在工作的时候,由于金属丝不仅仅存在弹性变形,而且其间还存在着干摩擦及扭转变形,此作用机理导致了金属橡胶隔振器的减振系统为非线性特性。首先从阻尼力及弹性力两部分建立减振系统的数学模型,其间采用了多尺度法对其非线性特性进行了分析,推导出了非线性隔振系统的激励频率与响应振幅的关系式。与一般线性系统响应特性对比,得出了非线性隔振系统的响应特性。     

金属丝网减振器的建模与参数识别

针对金属丝网减振器的滞迟特性和非线性关系,利用金属丝网减振器的静态特性试验得到载荷-位移曲线,并由此建立了金属丝网减振器的滞迟恢复力模型,将恢复力g_n分解为无记忆部分g_0和记忆部分z(t),并分别用间接Fourier展开法和直接Chebyshev展开法对减振器双折线本构关系进行级数展开和参数辨识,通过参数识别数值模拟得出Chebyshev级数展开识别法的精度略胜一筹,为建立金属丝网减振器非线性泛函本构关系与动力学模型提供了坚实的实验基础和理论指导。     

金属丝网减振器的建模与参数识别研究

针对金属丝网减振器的滞迟特性和非线性关系,利用金属丝网减振器的静态特性试验得到载荷-位移曲线,并由此建立了金属丝网减振器的滞迟恢复力模型,将恢复力gn分解为无记忆部分g0和记忆部分z(t),并分别用间接Fourier展开法和直接Chebyshev展开法对减振器双折线本构关系进行级数展开和参数辨识,通过参数识别数值模拟得出Chebyshev级数展开识别法的精度略胜一筹,为建立金属丝网减振器非线性泛函本构关系与动力学模型提供了坚实的实验基础和理论指导。     

解耦膜与节流盘对液阻悬置动态特性的影响

分析了一种带解耦膜的液柱共振式液阻型橡胶隔振器的结构,结合液-固直接耦合有限元分析方法,建立了隔振器的一体化有限元模型,进行了不同激励频率下的隔振器动态特性计算和工作过程分析.结果表明解耦膜在低频范围也发生了变形,通过调整解耦膜的数量和刚度均可改变隔振器的低频动刚度和滞后角特性.在原方案基础上增设不同结构参数的节流盘并计算隔振器的动态特性,分析了节流盘的设置对隔振器动刚度和滞后角的低频峰值及其对应频率的影响,同时研究了隔振器的低频动态特性曲线随节流盘直径和杆长变化的规律.通过实验验证了有限元计算和分析的有效性.基于液-固直接耦合分析技术的有限元建模方法能够有效反映隔振器内部结构的实际工作过程和动态特性的变化规律,可以用于具有复杂结构的液阻型橡胶隔振器的性能分析和结构设计中.     

金属橡胶隔振器动力学模型与分析

综合考虑金属橡胶隔振器的阻尼形成机理,对金属橡胶隔振器的恢复力进行非线性描述,建立了动力学模型,对金属橡胶隔振器的动力学特性进行了研究,在理论研究和实验研究中采用了能量法进行金属橡胶隔振器的参数识别.同时将实验研究结果与理论研究结果进行了对比分析,验证了识别方法的正确性和准确性.图5,参10.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that