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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。

High volume fraction interface begins to form on the surface by surface nanocrystalline treatment, supplying ideal entryway for the diffuseness of chemical elements, and can markedly lower the temperature and time of chemical treatment and enhance infiltration concentration and deepness.

金属表面自身纳米化处理可以在各种金属材料的表面获得纳米晶组织,而且纳米结构层与基体之间没有明显的界面,在使用过程中不会因为外界条件的变化而发生剥层和分离,能够明显地提高材料的表面和整体性能。

It is very difficult to eliminate these influence factors completely by conventional treatment. Surface properties and surface treatment of ultrafine red phosphorus and MMT and their interface properties with polymer matrices were studied in this thesis. The results were characterized by GC, FTIR, XRD, DTA, TG, XPS, UV, SEM, TEM and other physical and chemical methods. The main contents are as following: 1. The study of factors influencing ultrafine red phosphorus's invariability and phosphine liberation indicated red phosphorus undergone oxidation and dismutation reaction in air, and trace ion of iron, copper and nickel fastened water absorption and oxidation, in which the effect of copper ion was the most, while aluminium and zinc ion could slow down red phosphorus'oxidation, and silver ion had the best effect on red phosphorus moisture absorption. Inhibitors such as aluminium hydroxide, magnesium hydroxide, organic phenol and ferrous potassuim cyanide had a good effect on reducing red phosphorus moisture absorption and restraining phosphine liberation.

本文围绕纳微米材料的表面处理及其在高聚物基体中的应用这一主题,系统地研究了超细红磷和蒙脱土两种常见材料的表面特性、表面处理方法及其与高聚物基体的界面特性,通过气相色谱、红外光谱、X射线衍射、差热、热重、X射线光电子能谱仪、紫外光谱、扫描电镜、透射电镜等现代分析仪器以及其它物理、化学方法对实验结果进行了表征和分析,全文主要内容如下: 1、对影响超细红磷安定性的因素以及磷化氢的缓释研究表明:红磷在空气中发生缓慢氧化、歧化反应,微量的铜、铁、镍等金属离子增加了它的吸水和氧化速度,其中铜离子的作用最为明显,而铝、锌等离子减慢了红磷的氧化速度,银离子对减少红磷的吸湿性效果最好。

The method includes identifying (101) a surface in the image, and for each point in the image, calculating (102) a first curvature measure, forming (103) a set of rings of points about each point, each ring being of equal geodesic distance from a center point for the ring, calculating (104), for each ring, a standard deviation of the first curvature measure, and selecting (105) those rings with a minimum standard deviation for the first curvature measure.

该方法包括在所述图像中识别(101)表面;为该表面中的每个点计算(102)第一曲率量;为该表面中的每个点形成(103)围绕每个点的一组点环,每个环具有到该环的中心点的相等的测地距;为每个环计算(104)第一曲率量的标准偏差;以及选择(105)那些具有第一曲率量的最小标准偏差的环。

An operating member which has a depression having an oblique push-up surface and a closing surface contiguous to its push-up surface is held movably in a accommodating portion formed in the case band and crossing the lower end of the stepped hole at right angles thereto.

具有凹陷部的操作构件可移动地保持在容纳部位内,凹陷部具有倾斜的上推表面和毗邻上推表面的关闭表面,容纳部位形成在表环内并与台阶孔下端成直角交叉。

Based on the fundamental principles of the improved method mentioned above, multi-functional computation software package, which can be used to analyze effectively the interference effects of random flaws in plane problem, boundary problem and space problem, is compiled and a number of problems involved in the interference effects of different kinds of flaws such as random equal length through-cracks, random branched throughcracks, random unequal length through-cracks, random holes to through-cracks, unequal length edge cracks, equal length and distance multiple edge cracks, random notches with different aspect ratio, random notch to edge crack, non-coplanar surface cracks with different aspect ratio, staggered surface cracks, surface crack to embedded crack and embedded cracks near free boundary are analyzed and computed by the package.

依据上述改进法的基本原理,本文编制了能有效地分析平面问题,边界问题及空间问题的任意缺陷群相互干涉效应的多功能计算软件包。据此,本文分析计算了各类缺陷群。诸如,任意等长裂纹群。任意折裂纹群;任意不等长裂纹群,任意孔与裂纹群,不等长边裂纹群。等长等间距多裂纹群,任意形状比缺口群,任意缺口与边裂纹,非共面不同形状比表面裂纹群,交错型表面裂纹群,表面裂纹与埋藏裂纹群及自由边界附近埋藏裂纹群等的相互干涉效应问题。

Polypropylene its superior performance has been widely applied, but their smaller polar surface, resulting in surface water and surface bonding of poor has greatly limited the scope of its application development.

聚丙烯以其优越的性能已经得到了广泛应用,但是其表面极性较小,导致表面亲水性和表面粘结性较差,极大地限制了其应用范围的拓展。

By using kinetic method,surface charge properties of neutral purplish soil and latosol were studied in this paper.

现在,对于测定任何土壤表面电位、表面电荷密度的方法,使方便地获得土壤表面电化学参数成为可能[3]。

The mean velocity distributions in turbulent boundary layers of smooth surface and two different riblet surfaces are measured with IFA300 constant-temperature anemometer in low-speed wind tunnel to validate the full development of turbulent boundary laye. Friction velocity and wall friction stress of turbulent boundary layer are obtained with the least-squares fitted curve of the sublayer velocity distribution based on Spalding formula, and virtual origin position of riblet surface can be acquired accurately.

在低速风洞中来流速度一定的情况下使用IFA300恒温热线风速仪测量了光滑表面和两种不同尺寸的脊状表面湍流边界层平均速度分布剖面,并验证了试验段湍流发展的充分性;通过应用Spalding壁面公式使用最小二乘法精准拟合了实验测量的边界层内层速度分布曲线,得到了湍流边界层壁面摩擦速度并进一步求得湍流壁面摩擦应力,较准确地计算出脊状表面的虚拟原点位置,并通过与对数律公式拟合结果比较分析,证实了该方法更加准确有效。

At present,the rate laws and reaction mechanisms of pyrite oxidation,pyrite and chalcopyrite formation,uraninite and magnetite dissolution in aqueous solutions are mainly studied,and it is discovered that (1)oxidation rate of pyrite controlled by surface reaction assume fractional dependence on Fe3+ and O2 molalities in acid solutions;(2)Pyrite cannot nucleate directly from solutions below 300 ℃,it can only form initially through sulfidation of a FeS precursor. The rate equation of reaction between FeS and H2S to form pyrite is of the second order;(3)Chalcopyrite is formed by reactions of pyrrhotite or pyrite with Cu2+,the former proceeds via a series of mediate metastable phases of Cu-Fe sulfide,whereas the rate equation of the latter is apparently of the first order which is controlled by surface reaction;(4)The nonlinear behavior of magnetite dissolution at acid pH can be represented by a shrinking core model coupling with surface reaction and diffusion transport.

目前主要研究了水溶液中黄铁矿氧化、黄铁矿和黄铜矿形成、晶质铀矿和磁铁矿溶解的速率定律和反应机理,发现:(1)酸性溶液中黄铁矿的氧化速率对Fe3+和O2浓度呈分数依赖并受表面反应的控制;(2)低于300 ℃时黄铁矿不能从溶液中直接成核,而需初始地通过FeS先驱物的硫化生成,FeS与H2S反应形成黄铁矿的速率方程为二级;(3)磁黄铁矿或黄铁矿与Cu2+反应均可形成黄铜矿,前者经历了一系列准稳的Cu-Fe硫化物的中间物,后者的速率方程为表观一级并受表面反应的控制;(4)酸性pH时磁铁矿的非线性溶解行为可采用表面反应扩散输运耦合的收缩核模型来描述。

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If you are unfortunate enough to the lovelorn, please tell me, I will help you out, really, please contact me!

如果你不幸失恋了,请告诉我,我会帮助你摆脱困境,真的,请联系我啦!

China's plan to cut energy intensity by 20 percent and pollutant discharges by 10 percent between 2006 and 2010 is a case in point.

中国计划在2006年到2010间降低20%的能源强度和减少10%的主要污染物排放,就是一个这样的例子。

Well, Jerry would rattle off all the details of that movie.

那么,杰瑞会急促背诵那部电影所有细节。