可变换性

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。

The Non-perfect Elastic Collision DC model in half space is presented, considering the influence of participating soil mass and the interaction of tamper and ground during DC. Series solutions of displacement, velocity, acceleration and impact stress are obtained.

通过与边界元法、Laplace—Hankel联合反变换法的计算结果，以及山西某湿陷性黄土地基和南京某填土地基工程中的实测数据的验证和对比表明，该模型是符合实际的，它可用于分析强夯规律，计算冲击应力，解释强夯加固机理和工程中的现象，便于工程应用，而且比其他方法简单易行。

Bring forward a kind of learning algorithm fitting on the base of spline function, because the spline function has good flexibility and quadratic smoothing property, the search problem of network weight functions training can be converted into the resoluting extreme value problem of the plurality function through using spline function to represent network input and link weight functions, thus the PNN can be trained with the help of the existing neural network learning algorithms;④build a kind of learning algorithm base on the alternate of Walsh function, the complexity of network computing can be decreased through using the complete orthogonality of Walsh function corollary.

应用结果表明该算法收敛速度快，稳定性好；③提出了一种基于样条函数拟和的学习算法，由于样条函数具有很好的柔韧性和二次光滑性，将网络输入函数和连接权函数用样条函数的形式表示，可把网络权函数训练的函数寻优问题转换为多元函数求极值的问题，从而可借助于现有的神经网络学习算法训练过程神经元网络；④建立了一种基于Walsh函数变换的学习算法，利用Walsh函数系的完备正交性，可大大降低网络计算的复杂度。

Holistic naturalism is the theoretic prerequisite of Quine's theory of linguisticrelativity,from which Quine advances a serial of indeterminacy theses and doctrines andshows the relativity of language:the doctrine of underdetermination of theory showsthe relativity of whole describing of language;the thesis of indeterminacy of translationshows the relativity of linguistic paraphase;the doctrine of inscrutability of referenceshows the relativity of linguistic reference;the transformation of ontology shows thereducibility of ontology in the language.

奎因语言相对性理论的哲学前提是整体论自然主义，正是由此出发奎因阐发了一系列的不确定性论题，展现了语言的相对性：理论的不完全决定性学说表明了语言整体描述的相对性；翻译的不确定性学说表明了语言解释的相对性；指称的不可测知性学说表明了语言指称的相对性；本体论的变换表明了语言中本体论的可化约性。

The high resolution image of full hole can be obtained from the being processed imaging logging information, and the morphological features about intersecting lines of fracture face and borehole present monocyclic sine curve.

成像测井数据经处理后可得到全井壁高分辨率的图像，而裂缝面与井筒的交线在图像上的形态特征呈现为单周期的正弦曲线，应用哈夫变换的点－线对偶性拾取图像中的裂缝角度等信息，可得到较好的处理结果。

WHMM is a statistical model in wavelet domain of stochastic signals, which integrates wavelet transform into hidden markov models . According to the locality, multiscality of wavelet transform and context-sensitive property of HMM, WHMM can not only characterize precisely the local feature of object multiscally, but also reflect accurately the full structure information of object. So it is a powerful tool which deals with noise, shape similarity and part occlusion in ATR, and finds its full application in recognition system of moving vehicle.

小波隐马尔可夫模型是小波变换与隐马尔可夫模型相结合的一种小波域随机信号的统计模型，它有机地融合了小波变换的局部分析性、多尺度性和隐马尔可夫模型的上下文相关性，不仅能多尺度地精确刻画目标的局部特征，还能准确地反映目标的整体分布信息，从而成为解决目标识别中受噪声、形状相似、部分遮挡等问题的最有力的工具之一。

The hardware circuitry of the whole digital scan conversion system is realized through the complex programmable logic devices so as to improve stability, flexibility and real-time of the digital hardware circuitry. A high-performance digital scan conversion system is researched and developed.

整个数字扫描变换系统的硬件电路都使用复杂可编程逻辑器件实现，增加了数字电路系统的实时性、稳定性和灵活性，设计和实现了一种高性能的数字扫描变换系统。

Based on the existence condition of the solution for singular ordinary differential systems,the existence condition of the solution of the degenerate neutral differential system as well as the general solution are obtained by defining the solvable matrix pair and fundamental solution and using Laplace transformation.

讨论了对于退化矩阵E不是方阵情形的一般退化中立型微分系统的解，基于退化的常微分系统解的存在性条件，通过定义可解阵对和基础解以及利用拉普拉斯变换，给出了一般退化中立型微分系统解的存在性条件以及通解表达式。

Unfortunately, the variables of the tensor multiplicative wavelet function are separable, and wavelets analysis is often fail when it is used to represent the higher sigularities.

小波变换是目前已知的对信号\函数的点奇性进行描述的最好工具，但对于高维奇性，可分离变量的张量积小波分析常常会失效。

Through transposition and transmission of reachability ,it is used to eliminate unknown relations using of reachability and reachless relations from initial matrix and using of interactive method.

这种方法从初始可达阵开始，利用可达关系的传递性，经过一系列的变换，消除一部分未知关系，再利用不可达关系，进一步消除一部分未知关系，最后采用人机交互的办法消除剩余的未知关系，从而得到利用可达矩阵表示的系统结构模型。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。