使光滑

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。

The derivatives of the nonsmooth equations are computed to make the generalized derivative matrix nonsingular. Then the nonsmmoth damped Newton method is used to solve them.Analytic solutions of the KdV equation with variable coefficients: Shallow water wave problems belong to problems of free surface wave, and can be molded by the nonsmooth equations model given above in principle.

在前面建立的非光滑方程组数学模型和固定网格法基础上，利用广义导数的概念给出了求解渗流自由面的一种新方法-----非光滑阻尼牛顿法，该法是对非光滑方程组求导，适当的处理广义导数矩阵使其非奇异，利用非光滑牛顿法求解。

It is so smooth and glides on with a luminous look to it.

它是，因此使光滑和滑翔与光亮神色对它。

The juices from the meats or vegetables result in a caramelized glaze which add depth to the flavor of the food.

装玻璃，/上釉于，上光，使光滑，使光亮，/变得呆滞无神；发呆

The results show that the concave structure ameliorates the surface stress distribution of the non-smooth sample, makes the local stress between concaves less apparently than that of the smooth sample, that means the local low stress areas are formed on the non-smooth surface.

结果表明：在受力状态下，仿生非光滑凹坑改善了试样表面的应力分布，使非光滑试样表面凹坑间的区域局部应力明显小于光滑试样表面的应力，即产生了局部低应力区。

The results show that the concave structure ameliorates the surface stress distribution of the nonsmooth sample,makes the local stress between concaves less apparently than that of the smooth sample,that means the local low stress areas are formed on the nonsmooth surface.

结果表明：在受力状态下，仿生非光滑凹坑改善了试样表面的应力分布，使非光滑试样表面凹坑间的区域局部应力明显小于光滑试样表面的应力，即产生了局部低应力区。

Each of the elevated temperature curves is moved along the horizontal time axis to longer times until it superposes on the reference temperature curve as smoothly as possible and then the master creep curve is obtained.

沿时间轴水平移动非参考温度下的蠕变曲线段使之与参考温度下的曲线图光滑连接，形成一条光滑的主曲线图。

Make(one's hair,a cat 's fur,etc)sleek

使光滑而发亮。

The major works are as follows: 1 The 3-D numerical model of U-sharp flow passages is set up. The single-phase fluid flow and heat transfer are simulated for the U-sharp smooth and rib-roughened flow passages with FLUENT software. Their performance curves, temperature field and velocity vector are obtained and the local heat transfer and flow pressure-drop distribution along flow passage are analyzed. It is revealed that the ribbed flow passages can enhance heat-transfer and make the temperature more uniform, but it increases the pressure-drop to more extent. 2 The influences of diaphragm depth, channel width and board spacing on the performance are investigated.

建立了层叠式蒸发器U形流道的3维湍流模型，用FLUENT软件对尺寸相同的U形光滑流道和肋化流道中单相流体的传热和流动进行了数值模拟，得到了两种流道的传热和阻力性能关系曲线及速度矢量图、温度场，分析了光滑流道和肋化流道的局部换热系数及沿程压降变化，结果表明流道的肋化能有效的增强传热，而且使流体的流动和传热更加均匀，但也较大地增大了阻力。

In this part, the set of CODONs is extended so that both open and closed curves containing straight lines and cusps can be completely represented.

该部分研究主要将传统的基于封闭光滑轮廓的CODON编码推广至任意非封闭非光滑曲线，使图像的CODON编码能更加完备地表征图像轮廓。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。