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The effect of tribology factors on bearing vibration is studied experimentally. AR model and WPT are used to processing the normal arid abnormal signals. The results are as follows:1. The vibration of ball bearings is caused by the tribology action of contact pairs of ball and ring races and has the essential of tribo-dynamics. Any factors affecting the tribology characteristics of contact pairs will affect vibration and noise of bearings consequently.2. Vibration characteristics of bearing keep almostly unchanged with the increasing of axial load expecting the increasing of nature frequencies. When radial load increasing with axial load unchanged, nature frequencies keep unchanged but some new vibration peaks appears in the spectrum.3. Vibration amplitudes are damped and nature frequency are enhanced with sufficient lubrication. Vibration and noise of bearings increase obviously and roar can happen and the contact surfaces scratch slightly under insufficient and unclean lubrication state. Bearing will be disabled in a few minutes without any lubrication.4. Bearing vibration is unstable under low speed. With the speed increasing, the vibration become stable and natural frequencies increase slightly but the amplitudes increase apparently.5. Bearing vibration can be excited only by some harmonics ofwaviness without lubrication and by all harmonics with lubrication based on the theoretical analysis.6. The nature frequencies of ball bearings decrease with the increasing sizes. When international clearance increasing, nature frequencies decrease in radial and increase in axial and angular and the amplitudes increase in radial and decrease in axial and angular. When the number of balls increasing, nature frequencies increase and amplitudes decrease. When the pitch diameter increasing, axial nature frequency increase and others nearly keep no change. When outer race groove curvature radius increasing, nature frequencies increase in radial and decrease in axial and angular and amplitudes keep no change in radial and increase in axial and angular. When inner race groove curvature radius increasing, nature frequencies decrease and amplitudes increase.7. The distortion in amplitude and frequency components of bearing vibration signals picked up by the present probe measurement method is founded and right conclusions cannot be achieved by the signals. When accelerometer is rigidly screwed with steel stud onto a flat outer surface of a ball bearing, vibration signal can be got without distortion and the reliability of research on bearing vibration is assured.8. AR model is suitable for large samples of bearing vibration signals, square root of length of samples can be used as the upper limitation of order determination and the FPE order selection criterion is effective. Many advantages of AR spectrum are founded over the classical based on FFT.9. Time-Frequency analysis is necessary for abnormal noise of ball bearings. WPT overcomes the principle shortcomings of STFT and proved to be a best tool to process the abnormal signals.

理论分析和试验研究表明： 1球轴承振动是钢球—滚道接触副中的各种摩擦学作用引起的，具有摩擦动力学的本质，任何对接触副的摩擦学特性有影响的因素都将对球轴承的振动和噪声特性产生影响； 2中心轴向载荷作用下，载荷增大使球轴承的固有振动频率升高，载荷越大同样的载荷增幅引起的频率升幅减小，足够大的中心轴向载荷作用下载荷的变化对球轴承振动的频率特性不会产生明显的影响； 3轴向和径向联合载荷作用下，径向载荷不大时球轴承振动的固有频率基本不变，但是可能引起变刚度激励的非线性振动，出现新的频峰，过大的径向载荷将使部分钢球脱离接触，使球轴承的振动和噪声呈现不稳定状态； 4润滑对球轴承的振动和噪声特性有重要的影响，良好的润滑对振动有明显的抑制作用，润滑不充分时，振动和噪声的水平会有明显增高，一定条件下还会激发接触副中的谐振，发出啸声，造成接触表面的伤害，无润滑干接触时，短时的运转就会损伤接触副表面，使振动和噪声迅速增大，并随时可能引发严重的磨损和卡滞失效；接触副润滑良好时，油膜的"刚化效应"使球轴承振动的固有频率有所提高，润滑剂中含有弥散性污浊时，振动的幅度总体升高，但弥散性污浊不会改变球轴承振动的频率特性；浙江大学博士学位论文：球轴承振动的研究 5低速时，球轴承振动的基本特征呈现不稳定状态，随着转速的提高，球轴承振动的频率特性趋于稳定，固有频率频峰升高； 6理论分析表明，干接触时钢球和滚道表面波纹度的某些谐波分量能激励球轴承的振动，振动的幅值与谐波幅值成正比，实际球轴承中钢球的分布不可能完全均匀，波纹度的激励作用会随时发生；润滑接触的分析表明，波纹度的任意谐波分量均能激励球轴承的振动； 7球轴承的几何和结构参数分析表明，球轴承尺寸越大，径向、轴向和角振动的固有频率越低；钢球中心圆直径增大，球轴承的径向和轴向振动的固有频率基本不变，角振动的固有频率有所上升，振动的幅频特性基本不变；径向游隙加大使球轴承的径向振动固有频率降低，轴向和角振动的固有频率有所升高，径向振动幅频特性的幅值升高，而轴向和角向降低；钢球的数量增多使球轴承振动的固有频率上升，幅频特性的幅值下降，径向振动的幅值下降最为明显；外圈沟曲率半径系数增大使球轴承径向振动的固有频率升高，轴向和角振动的固有频率降低，径向幅频特性基本不变，轴向和角向幅频特性幅值升高；内圈沟曲率半径系数增大使径向、轴向和角振动固有频率均下降，振动幅频特性的幅值均有升高； 8试验对比表明，传感器采用探针式安装时，由于探针接触副接触特性的影响，钡(量得到的球轴承振动信号有失真，采用专门设计和制作的试验球轴承，以固定式安装加速度计，首次测量得到了球轴承振动的真实信号，通过对振动信号的分析，验证了球轴承振动的理论模型； 9)基于时间序列分析的AR模型适用于大样本球轴承振动信号的分析，以样本长度的均方根值作定阶上界，FPE做判阶准则，给出的AR谱光滑，频率分辨率高，是球轴承振动分析的简便而可靠的手段； 10以时频域分析的小波包变换分析球轴承异音信号能够比较好地定位和聚焦异音发生的时间，时间间隔，频率范围，同样是球轴承振动分析的可靠的手段，可用作球轴承故障诊断技术。

By comparing, both advantages and disadvantages of the two damping methods are obtained.

通过对两种方法的对比，总结出了它们各自的优缺点。

Moller-Maersk, Danmark in maritime logistics operation in China, analyzes how to carry our the brand strategy and how to keep the competitive advantages and gives out some suggestions on how to implement the brand strategy for the Chinese Logistics' enterprises.

通过SWOT对马士基公司进行全面的剖析，同时，通过对马士基公司内部最新的系统和政策的描述，分析了其在中国是如何展开企业的品牌战略、把品牌战略有效地融入传统行业，如何保持企业持续竞争优势、在中国这个巨大的市场上树立自己综合物流服务的品牌与企业形象，并对我国物流企业实施品牌战略提升竞争力提出了建议。

East Nanjing Sino-Russian trade zones with the top ten advantages: First, political advantage: China and Russia have set up long-term strategic partnership between the governor of Heilongjiang Province Zhang left on July 21, 2004 Russia's Primorsky Territory and the Chief Executive Dari Gold Nanjing East China and Russia signed a trade zones construction management and development cooperation agreement.

东宁中俄互市贸易区具有十大优势：一、政治优势：中俄两国已建立长期的战略伙伴关系，黑龙江省省长张左已于2004年7月21日与俄滨海边疆区行政长官达里金签署了东宁中俄互市贸易区建设管理与发展的合作协议。

In 1962, Peter Drucker, the famous master of economics and management, presents definitely that logistics was the last area for decreasing cost in his paper Economy"s Dark Continent published in fortune. For 40 years, the concept of logistics was expanded continually and more and more attentions were paid on it. Especially from middle of 1980"s to this day, with the increase of economic globalization and development of the information technology, more and more enterprises go back to their main businesses, and pay their points on these businesses such as product development, manufacture, marketing, which are their core businesses and they are good at. These businesses embody the competitive advantages of the enterprises.

1962年著名经济管理学大师彼得·杜拉克在美国《财富》杂志上发表《经济的黑暗大陆》一文，首次明确地提出物流是节约成本的最后领域。40年来，物流的概念在不断地拓展，人们对物流管理越来越重视，特别是80年代中期至今，随着经济全球化竞争的加剧、信息技术的飞速发展，许多生产企业回归主业，将精力集中于产品开发、生产、销售等具有竞争优势的核心专长业务的呼声日益高涨，理论界和企业界已不再浅层次的探讨物流管理的重要性问题了，他们开始探讨物流管理的模式问题，即：究竟是自营物流业务，还是将物流业务外包给专门从事物流管理的企业去做。

It has advantages of low cost; fast data transfer rate and so on.

具有成本低、数据传送速率快等优势。

This system has the advantages of small size, low power dissipation and wireless transmission of data etc.

设计的系统具有体积小、功耗低及数据无线传输等优点。

List and describe the advantages of database administration.

列出并描述资料库管理的优点

In this paper, the advantages of diagnosis and analysis system, and system design, the case has been replaced by a database query module and call the document analysis algorithm, design and implementation of a detailed presentation.

本文阐述了诊断分析系统的优势，并对系统的总体设计、已实现的病例查询模块及取代数据库的调用文档算法的分析、设计及实现过程做了详细的介绍。

Analysis on the current condition of the database access on Traditional Call Center, including advantages and disadvantages of C/S model.

根据呼叫中心的开发思想，结合OCI、DB-Library数据库访问接口的设计理论，研究了现代呼叫中心数据库接口的实现及其技术。

Hanna: That's over now, isn't it?

都结束了，对吗

You must be ill. You look so pale.

你一定是病了，你的脸色苍白。