向轴的

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。

Yuan Zhesheng's fiction often recounts family and father-son stories. His most celebrated feature is his speculation on time. Imaginative games in enclosed space also turn up frequently in his writings. Therefore, a research framework consists of time, space and human world is a criterion that delineates a fictionist's image of mind in three-dimensions.

袁哲生写得最多的是家庭、父子小说，最为文坛知悉的是时间的思索，最常出现的场景是闭锁空间的游戏想像，因此时间、空间、人间三向轴的研究架构，是为立体化小说家创作心象所设的凖的。

To analyze the pseudo phenomena caused by migration velocity error, the paper firstly studied the depth error between post-stack migration and prestack migration caused by same velocity error, and found the depth error was only relative to velocity error and had no direct matter with methods of depth migration (post-stack migration or prestack migration). Then the paper did numerical simulation of a complex lenticular body model with wave-equation modeling and migration, and found that the velocity error could not only induce depth error, but also could change the modality of construction and the event of subjacent layers. Furthermore, it could change the frequency of reflective event. They are the pseudo phenomena caused by migration.

从分析偏移速度误差带来的各种假象出发，本文首先对比分析了速度误差对叠后深度偏移和叠前深度偏移的影响，发现偏移剖面的深度误差仅与速度模型的误差有关系，与具体的偏移方法没有直接的关系；然后对一个复杂的透镜体模型进行了波动方程叠后正演和偏移计算，详细地讨论了不同的速度误差带来的各种假象，发现速度误差不仅会带来深度误差，而且会造成构造体的形态变化，下覆地层同向轴的扭曲，还可能引起地层同向轴的频率发生变化，给资料解释带来一定的假象。

In this paper, several methods are put forward, by which axial resolution of scan microscope could be improved. One is that detecting method of ordinary laser feedback is improved, the orthogonal polarized lights split by Wollaston prism are detected separately, comparing to the ordinary feedback, the axial resolution is improved about 2.9 times.

提出并实验研究了几种可以提高激光反馈扫描显微镜轴向分辨率的方法，一种方法是对常规激光反馈实验中的探测技术进行了改进，用渥拉斯顿棱镜把垂直偏振光分开探测，轴向分辨率可以提高约 2 9倍；另一种方法是用双频激光器中产生的偏振态相互垂直的o光和e光作为反馈光代替了传统的单一光的反馈，轴向分辨率被提高了约 2倍；第三种方法是用双频激光器中产生的o光或e光作为反馈光，轴向分辨率可以提高约 2 5倍。

In contrast, P. obliquum has lamina with basal pinnae contracted, scales of petiole brown adaxially, scales of rachis up to 2.3×0.5 mm, pinnae green, chartaceous, matt adaxially, and serrulate on margin, and microscales 0.2-0.5×0.1-0.2 mm.

obliquum相似，但吞天井耳蕨的叶片基部最宽，向基部不缩短，叶柄鳞片近轴面深棕色，叶轴鳞片达3.6×0.8mm，羽片深绿色，近革质，向轴面有光泽，边缘具略波状微齿或近全缘，小鳞片达2×0.5mm；而斜羽耳蕨的叶片的基部缩短，叶柄鳞片向轴面棕色，叶轴鳞片达2.3×0.5mm，羽片绿色，草质，向轴面无光泽，边缘有锯齿，小鳞片达0.5-0.8×0.2-0.3mm。

Existing procedure for change management to C type cardan shaft is not adequate when considering a change to the tools used in the manufacturing process.

当制造工艺中运用的工具发生改变的时候，现有的对C型万向轴的改变管理程序不够完善。

The analysis of structure and principle of operating of cardan shafts between transmission boxes and starting generators of Beijing locomotives reveals the main reasons of scrapping of cardan shafts.

通过分析北京型机车传动箱和起动发电机之间的万向轴的结构及在机车运用中的动作原理，确认造成万向轴报废的主要原因，结合实际调查，阐明修复工艺及修复效果。

The sliding gear assembly consists of sliding shaft, sliding gear and sliding clutch. The sliding shaft coaxial with the driving shaft has one end stretched into the axial hole on one end one the driving shaft and the other end supported on the front end casing; and the driving shaft is fixed axially onto the pedestal.

滑动齿轮组件由滑动轴、连接在滑动轴上滑动齿轮、连接在在滑动轴上的滑动离合器组成；滑动轴与传动轴同轴；滑动轴的一端的伸入在传动轴的一端沿轴向所开的孔内，另一端支撑在前端壳体上；传动轴在轴向被固定在底座上。

The results show that the vibration intensity of the substructure has a connection with the depth of the well, the geological condition and the density of drilling fluid; the horizontal vibration of the substructure is mainly caused by bent kelly; the included angle between the axis of cardan shaft and the derrick floor is also the cause of the vibration in three directions, and the cause of t...

分析结果表明，底座的振动强度与井深、地质条件和钻井液密度有关；弯曲的方钻杆是造成底座水平方向振动的最主要原因；万向轴因与钻台面存在夹角，从而引起底座在三个方向的振动；采用四挡钻进时，万向轴的工频及其倍频接近底座垂直方向的固有频率是引起底座在该方向振动强烈的原因。

Therefore, for improving the accuracy of exceed slender axle on turning,must need to do with the lathe fixture and cutting tool for further improvement. In order to reached the requirements of precision machining,in machining process must use follower rest、flexible active thimble、space block and bracket etc fixture and assistive device.

超细长轴在车削加工中承受自身重力、切削力、高速旋转产生的离心力的作用，极容易出现振动与弯曲变形现象，增大轴的几何形状误差，而超细长轴的轴向尺寸较大，直径较小，热扩散性及刚性差，受切削热作用会在轴向发生线性膨胀，若在轴向的伸长量无法得到消除，轴将受迫弯曲，从而影响轴的精度。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。