磨损性

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。

Proceed from the principle of neural networks, the mechanism of mapping between input and output of neural networks was analyzed, and the BP algorithm for training the thresholds of neurons was derived. Based on the study to the distinguishability of input of networks, the effect of neural networks to distinguish-ability of characteristics was studied, and the optimizations of the structure of networks, learning rate, impulse factor, thresholds of neurons and initial weight of networks were completed. Through the experiments under fixed cutting regime and alternative cutting regime, the methods based on neural networks for tool wear monitoring were studied.

本文从神经网络的基本原理出发，研究了神经网络输入输出的映射机理，探讨了神经网络处理方法具有自适应性的原因；推导了神经元阈值学习BP算法；在研究网络输入特征可分性准则和特征敏感性准则的基础上，探讨了神经网络对特征可分性的作用；完成对网络结构参数、网络学习率和冲量因子、神经元阈值以及网络初始权值等参数的优化；并在固定切削用量和变切削用量条件下，对基于神经网络的刀具磨损检测方法进行了实验研究。

Finally, by studying on using saw blades with different matrices cutting different stones, a basic compatibility rule about matrices and stones was concluded, say, when cutting a hard, high quartz and high alkalifeldspar content and strong bonded stone, a high impact strength and low wear-resistance matrix should be chosen; otherwise, when cutting a soft, low quartz or no quartz content and weak bonded stone, a high bending strength, low impact strength and high wear-resistance matrix should be chosen.

最后，通过对不同性能结合剂的锯片切割不同石材的切削寿命和磨损状态分析，得出了锯片结合剂性能与岩石性质之间的一般性匹配原则：即对于坚硬的、高石英含量的花岗岩，宜选用高强度、高冲击韧性、低耐磨性和对金刚石具有良好粘结性能的结合剂；对于低硬度、无石英或低石英含量的易切削花岗岩，宜选用高强度、高耐磨性和低冲击韧性的结合剂。

In order to resolve the part distortion problem of 16Mn scaleboard used in the sluiceway of No.

为解决 5 #、6#高炉冲渣沟原 16Mn衬板因冲蚀、腐蚀磨损严重，局部翘曲变形的问题，采用耐蚀性及耐磨性均较好的玄武岩铸石板作为冲渣沟内衬。

Based on the failure analysis of hot roll, this paper optimizedly adjusts alloy system and summarizes the experience of rolling wiresand improves ail processing properties. Then, it analyses the effects on some natural parameters such as alloy transfer coefficient, surfacing layers, welding current and arc voltage etc.. It confirms the fitting ageing technique. Also, it discusses the microscopic structural transformation back and forth ageing and the effects on hardness change of overlaying metal by some alloying elements including C, Cr, V, W, Mo, Ni, Mn, B, Re through OM, SEM and X-ray diffraction analyses. Finally the abrasive resistance, red hardness, thermal fatigue property and anti-high temperature oxidability are investigated in experimentation.

全文在热轧辊失效分析的基础上优化调整合金体系，总结了焊丝轧制的经验，改善各种工艺性能，分析了几个特性参数的影响，确定了适宜的时效工艺，并通过光学显微镜、扫描电镜和X-射线衍射对时效前后的显微组织转变以及部分合金元素如C、Cr、V、W、Mo、Ni、Mn、B、Re对堆焊层硬度变化的影响进行分析，最后通过试验考察了堆焊层金属的耐磨粒磨损性能、红硬性、耐热疲劳性和抗高温氧化性。

English:Activated alumina is a porous solid material with high dispersion and large specific surface area, which has fine adsorption capability, fine pressureproof performance, fine wear resistant performance and fine heat-resistant performance, and as a result it is widely used as adsorbents.

产品简介：活性氧化铝是一种具有多孔性高分散度的固体物料，有很大的比表面积，既有良好的吸附性能，又有良好的耐压、耐磨损和耐热性能，因而，被广泛地用作高效吸附剂、干燥剂本品为白色，球状多孔性物质无毒、无臭、不粉化、不溶于水。

Lytic defects have been reported with both stable and loose uncemented prostheses.75 In the late 1970s, several researchers76,77 made important initial contributions to knowledge about the role of particles generated by joint prostheses in the pathogenesis of osteolysis and aseptic loosening.

在稳定的和松动的非骨水泥假体中均发现溶解性骨缺损。19世纪70年代晚期，很多研究者都发现了由关节假体产生的磨损颗粒在骨溶解和无菌性松动的发生上起到的作用。

Iron-base fluxed alloy is produced by adding suitable amount of boron and silicon into iron-carbon alloy, which is usually used on the wearable and weak-acid-medium proofing accessories under 500℃. Although the performance of iron-base fluxed alloy can not match with that of the nickel or cobalt alloy, it has wide source materials and low prices, which is the great advantage for application.

铁基自熔性合金是铁——碳合金中加入一定量的硼、硅元素制成的，通常应用在常温——500℃以下耐磨损、耐弱酸腐蚀介质的机械零部件上，仅管铁基自熔性合金，综合性能不如镍、钴基合金，然而原料来源广泛，价格便宜，这是其得以普及应用的较大优势。

The whole hull has high stability, seakeeping performance and controllability, which reduces the abrasion on the apron and the requirements of its structure complexity. It has advantages of simple mechanical structure and easy realization.

本发明整个船体具有较高的稳定性、耐波性及可操纵性；减少了对围裙的磨损，同时也降低了对围裙结构复杂性的要求；机械结构简单，容易实现等优点。

Composed of round door frames, gate, rack , sealing strip, adjustable structure of sealing , this kind of sealing principle is door frame is fixed on square pipe of pool and wall, rack is fixed on door frame and wall, through rack opens and closes till weld block of gate meets with weld block of rack to make sealing surface of gate close to sealing surface of door frame to achieve sealing .Besides , sealing of gate and sealing of door frame are made of inlaid copper which is well resistance ,It makes valve with well sealing ,wear resistance , corrosion resistance, easily operation, convenient installation , long life , wildly usage.

本闸门是由圆型门框、闸板、导轨、密封条、可调整密封机构等部件组成，其密封原理是门框固定于水池圆型管道及墙壁上，导轨固定门框与墙壁上，闸板通过导轨做启闭动作，直到闸板上的锲块碰到导轨条上的锲块，使得闸门密封面紧靠门框上的密封面，从而起到密封效果，另外闸板密封面跟门框密封面都是镶铜材质的，具有耐磨损的特性，使得阀门密封密封性好、耐磨性强、耐腐蚀、操作简单、安装方便、使用寿命长、适应性广等特点。

He and Nina moved to California and lived at 2005 Ivar Street, Apt.

他和Nina搬到加州，并在2005年伊瓦尔街，公寓生活。

Droperidol （ potently inhibits transfected HERGchannels and this is the probable mechanism for QT prolongation.

氟哌利多有效地抑制了转染的 HERG 钾通道，可能是 QT 间期延长的机制。