状态

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。

A restoring to life from a deathlike condition; resuscitation.

回生，复活从象死的状态恢复为生命状态；复活

Health is not only a state of non - disease and non - debility, but also refers to a perfect state between human body, spirit and healthy society.

"健康是人类的肉体、精神和社会康乐的完美状态，而不是仅仅指无疾病或无体弱的状态。"

In the model investment, pavement distress and transportation capacity are selected as the decision variable, the state variable and the output variable, respectively.

基于投资决定路况、路况决定运力这一事实，以投资、路况和运力分别为控制变量、状态变量和输出变量，建立了道路系统的状态空间模型。

All substances, except those which decompose when heated, may be changed from one state into another.

所有物质，除了一加热就分解的以外，都可以以一种状态变为另一种状态。

Thus, a critical state is produced, in which the appearance of noxious factors would favor the development of a dedifferentiation process protagonized by the nervous functional system.

因此，一个临界状态产生了，在这种状态下有害因素的出现与神经系统的相关的去分化过程的发展密切相关。

The paper presents a flexible and effective method of development of negotiating agents. A strategy specification, which is specified by a state chart and defeasible rules, can be dynamically plugged into an agent shell incorporating a state chart interpreter and a defeasible logic inference engine, in order to yield a desirable age.

智能代理技术是实现自动谈判的有效途径，本文提供灵活有效的谈判代理开发方法，使用状态图和可废止逻辑规则说明谈判策略，动态地插入到一个集状态解释器和可废止逻辑推理引擎于一体的代理壳中，就可以获得所需要的自动谈判代理nt

A strategy specification, which is specified by a state chart and defeasible rules, can be dynamically plugged into an agent shell incorporating a state chart interpreter and a defeasible logic inference engine, in order to yield a desirable agent.

使用状态图和可废止逻辑规则说明谈判策略，将其动态地插入到一个集状态解释器和可废止逻辑推理引擎于一体的代理壳中，就可以获得所需要的自动谈判代理。

In Japan, following the collapse of the bubbles, the government reduces the rate forwardly, then the economy fall into the state of low inflation rate and low interest rate. Being afraid of inflation, the Bank of Japan is reluctant to further relax the monetary policy leading to the economy reviving very crisp. Under the external impact, the economy fall into the deflation, and the rate policy loses its effectiveness.

日本则是在泡沫经济崩溃后，政府为了促进经济增长，主动降低利率，进而使经济进入了低通胀低利率状态，但由于日本央行害怕通货膨胀，不愿意进一步放松货币政策，导致日本经济的复苏非常脆弱，在外部经济的冲击下，经济进入了通货紧缩状态，利率政策失效。

The main chemical compositions of tea flower were studied. It is the first time to determine the levels of protein, reducing saccharides and SOD activity in different blooming stages of tea flowers collected from three cultivars of Camellia sinensis with different picking time. Results showed that there were significant differences among cultivars and blooming stages, as well as the change of these chemical constituents along with time. Consequently we selected the right cultivar that has high protein, reducing saccharides or SOD activity and the fitting deflower time.

本文研究了茶花中主要化学成分的含量，首次对不同茶树品种、开花状态和采摘时间的茶花中蛋白质、还原糖含量，以及SOD活力进行系统研究，明确了不同茶树品种、不同开花状态茶花中蛋白质、还原糖含量和SOD活力的差异，以及这些化学成分随时间的变化规律，从而筛选出了高蛋白质、还原糖含量，以及高SOD活力的茶树品种和适宜的采花时间。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐