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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。

Histological structures of bursas of Fabricius were observed at the different developmental stages from chicken embryoes to chickens. The results were as follows. The bursa of Fabricius began to develop on the 13th day of post-hatching and its cell aggregated into the nodosity clique underneath the epithelium mucosae. On the 15th day of post-hatching, those cell cliques were surrounded by the flat epithelium and formed the basic structure of folliculus lymphaticus. The number of lymphocytes in the folliculus lymphaticus increased gradually, and the medulla and cortex of a majority of folliculus were not discriminated obviously. Until on the 7th day for chickens, the medulla and cortex of folliculus formed completely and the number of folliculus increased significantly. From 21 to 35 days old, the folliculus lymphaticus transformed from polygon into rectangle. Mucosa epithelial cells increased gradually and their cytoblasts arranged compactly into aline in the basilar part on the 35th day.

本研究观察了从鸡胚到出壳后的不同生长发育阶段法氏囊的组织结构，结果表明：胚胎13日龄时，法氏囊开始发育，粘膜上皮下形成结节状细胞集团；胚胎15日龄，聚集的细胞集团形成初始的淋巴滤泡；胚胎18日龄到出壳后1日龄，滤泡内淋巴细胞数量增多，多数滤泡髓质和皮质界限仍不明显；7日龄雏鸡法氏囊髓质皮质分界清晰，滤泡数量显著增多；21日龄到35日龄，滤泡由多边形逐渐转变成长方形；在35日龄时，粘膜上皮细胞逐渐增多，排列紧密，细胞核紧密排列成直线位于基底部。

And pulling out my perspective glass, which I had taken on purpose, I laid me down flat on my belly, on the ground, and began to look for the place

我平卧在山顶上，取出我特意带在身边的望远镜，向那一带地方望去。

Keep on and persevere in going forward, whether it is a narrow snaky road which bristles with thorns or a broad flat road, the scenery along the route will always change, you can choose to sing ditty happily and walk on or cry on the way.

一路走下去，坚持不懈地走吧，管它是荆刺密布的羊肠小道还是宽广平坦大道，沿途的风景总会变化，你可以选择快乐地哼着小调走着，也可以选择时时以泪洗面。

In toronto, in the chinese owned malls, we can buy electric motorbikes from c$700 to c$900. not bad to drive on flat roads on days without snow on the ground :— torontonian, toronto, canada

在多伦多，在中国人的商场，我们可以买到电动摩托车，从700加币到900加币，在地上没有雪的日子里驾驶在平坦的道路上，还不错。

On the basis of previously research, this paper re-probe into the mechanism of electro-chemist mechanical manufacturing process, making the rational technological parameter, and developing the manufacturing equipment. Through a lot of technology tests, get a lot of labratory data, accordingly, researched the surface feature of the electro-chemist manufacturing process, and deeply discussed its influence on the work piece feature. The last result is that: the electro-chemist mechanical manufacturing process can reduce the low-frequency component significantly, but on high-frequency component, it has little influence, having obviously positive pole flat effect. After manufacture, the tip parts on the surface of the work piece is cut off, there is micro "high land" shape, the parameter for surface roughness is reduced a lot, the surface outline of the work piece is negative, the bearing length rate is cliffy. Also the surface quality of the work piece is improved. This can help to avoid changing the shape, improve the feature of rub, gear and reduce the time to suit. This would also ensure the precision and result in a longer work piece life.

在以前研究的基础上，本论文重新探讨了电化学机械复合光整加工工艺的机理，确定了较合理的工艺参数，对电化学机械复合光整加工设备进行了改进，通过工艺实验广泛地搜集了大量实验数据，依据实验数据，多角度地研究了电化学机械复合光整加工的表面形貌特点，并且从理论上深入讨论了电化学机械复合光整加工表面形貌对工件工作性能的影响，最后得出的结论为：电化学机械复合光整加工对工件原始表面的低频成分有较大程度的降低，而对高频成分影响较小，有明显的阳极整平作用，被加工工件表面的尖峰状凸起被去除，工件表面呈现出微观&高原型&，表面轮廓不平度高度特性参数大幅度降低，工件表面轮廓分布集中，且呈负偏态，轮廓偏斜度为负值，轮廓支承长度率曲线陡峭，工件的表面质量得到综合改善，这对提高零件的抗接触变形能力、改善摩擦、磨损性能、降低工件的磨合时间、提高工件的精度保持性、延长工件的寿命均有利。

Note: When the canvas is squared, I put a staple on each of the corners, on the middle of the mitre line of the corner, on the top of the wood as it lies flat on the floor, because the stretchers tend to wriggle around during the actual stretching of the canvas, and get unsquared.

注：当画布，是平方，我把主食每个角落，对中间的人字线的一个角落，对顶部的木材，因为它所在单位在地板上，因为担架往往蠕左右在实际拉伸的油画，并得到

Another theory is that the toes on his back foot bend as walking on a flat surface, while on another sequence of the video which supposedly shot from Criss Angel's camera as he looks down while walking, his toes no longer bend.

另一个理论则认为，脚趾，他回弯脚走路放在一个平面上，而在另一序列的视频拍摄，其中理应由criss天使的相机，他期待下跌的同时，散步，他的脚趾不再弯曲。

XD-2003 strap machine is changed from XD-2002 machine which has a cast aluminium on the bed,making the screw,screwtube and speed reducer keeping concentric.the V-model manger on the bed is lower than the flat on which the speed reducer is fixed,the components are finished machining by machine tool.guaranteeing perpendicularity, degree of balance.speed reducer,screw and screwtube is fixed on the base,and the screwtube is in the mini-manger,then ensuring axis keeping concentric with sheath,screwtube feed opening has a chromium hard-wearing sheath,which can improve the lifetime of the screw and screwtube to threefold or to fourfold.

XD-2003 型塑料打包带机组，是在XD-2002型机组的机座上安装了一个铸铁机座，使螺杆，螺筒和减速机保持同心，座上的V型槽比安装减速机的平面低，其部件都是经过机床精加工完成的，保证了垂直度和平衡度。减速机和螺杆、螺筒置于底座上，且螺筒卡在微型槽内。确保轴与套保持同心，螺筒下料口处设有高铬耐磨衬套，这样可使螺杆、螺筒的寿命提高3-4倍。

We took turns with the mirror as we ate mulberries, pelted each other with them, giggling, laughing; I can still see Hassan up on that tree, sunlight flickering through the leaves on his almost perfectly round face, a face like a Chinese doll chiseled from hardwood: his flat, broad nose and slanting, narrow eyes bamboo leaves, eyes that looked, depending on the light, gold, green, even sapphire I can still see his tiny low-set ears and that pointed stub of a chin, a meaty appendage that looked like it was added as a mere afterthought.

我们一边轮流地玩着镜子，一边吃着桑葚，一边用它们砸着对方，一边咯咯哈哈地笑。我现在还能想象出哈桑坐在树上的样子，阳光透过树叶闪烁在他那张几近正圆的脸上。他的脸像一张硬木凿刻出来的中国娃娃的脸：扁平而宽厚的鼻子，细长的眼睛斜斜的，宛如一片竹叶，眼球因为光线的不同而呈现出金色、绿色，甚至是蔚蓝色。我还记得他那生得很低的小耳朵，还有下巴上粘着的那个明显的肉球，肉乎乎的，仿佛是事后再加上去的一笔。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。