无特征性

We first state general linear model, ridge-type estimator and general ridge-type estimator, and the constraint biased estimator. And then, we introduce some basic theory about matrix and some conclusion about the admissibility of estimator in Gauss-Markov model. In the third chapter, we discussion several equivalent characterization of the best linear unbiased estimation, we proved that admissible characterization of admissible of linear estimation is as conditional general ridge-type estimation in general linear model. A necessary and sufficient condition that homogeneous linear estimator is admissible estimator is obtained.

本文首先概述了一般线性模型，岭估计及约束岭估计的发展历史和研究现状，在第二章介绍了矩阵的一些基本知识和可容许性的一些基本结论，第三章讨论了一般线性模型最佳线性无偏估计的几个等价条件，以及线性估计的可容许性特征，得到了一般线性模型的可容许线性估计均具有条件广义岭估计的形式，给出了一个齐次线性估计为可容许估计的充分必要条件。

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。

We examined clinical, endoscopic, and pathologic data from 29 patients with isolated ileitis and no prior history of inflammatory bowel disease, and no colonic or upper gastrointestinal involvement.

我们检查了29例孤立性回肠炎患者的临床特征、内镜发现和病理特点，这些患者均无炎性肠病病史，亦无结肠或上消化道病变。

There arises tranquillity of mind with the characteristic of quietening the disturbances of consciousness and its mental concomitants; and along with it appear mental agility, etc.29 When walking, standing, sitting, or reclining there is, under the influence of these mental qualities, no disturbance of consciousness and its mental concomitants, nor heaviness, rigidity, unwieldiness, sickness, or crookedness.30 Rather, his consciousness and its mental concomitants are tranquil through having reached the supreme relief in non-action.31 They are agile in always functioning swiftly; they are pliant in being able to attend to any object desired; they are wieldy, in being able to attend to an object for any length of time desired; they are quite lucid through their proficiency, that is, through the ease with which insight penetrates the object; they are also straight through being directed, inclined, and turned only towards wholesome activities.

心轻安也会出现，具有让心和心所平静的特征，心轻快性等心所法也会伴随出现。由于心轻安等的作用，无论行住坐卧，心和心所都保持宁静而无扰动，没有粗重、僵直、不适、病态或扭曲的状态出现。此时，心和心所因为无作而极轻松，所以是轻安的；运作轻灵快捷，所以是轻快的；能够自在转向欲观照的所缘，所以是柔软的；对任何所缘的观照时间能随其所欲，所以是适业的；很容易深入清楚观照所缘，所以是明静的；总是朝向善行、倾向善行、转向善行，所以是正直的。

Being odorless, colorless, tasteless, and nonirritating, nitrogen has no warning properties.

由于无嗅、无色、无味、无刺激性，氮没有警告性特征。

Being odorless, colorless, tasteless, and nonirritating, argon has no warning properties.

由于无嗅、无色、无味、无刺激性，氩没有警告性特征。

A new picorna-like virus was isolated from dead Evtropis oblique larvae deceased from NPV infection. Electron microscopic observations of purified virions were non-enveloped isometric particles with diameter of 26nm. The virions contain two capsid proteins: 31.5kDa and 28.8kDa, the amount of later is 2.5 times more than that of the former. Analysis of 3′terminal sequence of EoPV clone identified that it can encode RdRp and has eight conserved motifs. Homology analysis shows that it is closely related to Perina nuda picorna-like virus.

从核型多角体病毒感染致死的茶尺蠖幼虫尸体中分离到一株微小RNA病毒透射电镜观察纯化的病毒粒子为无囊膜、无表面特征、直径约26nm的球状颗粒。16%的SDS-PAGE显示它有两个分子量为31.5 kDa和28.8 kDa的衣壳蛋白，后者的含量是前者的2.5倍。3′端克隆序列分析表明EoPV基因组3′有poly尾，编码RNA聚合酶，含有微小RNA病毒RNA聚合酶的八个保守基序，同源性分析表明它与榕透翅毒蛾微小RNA病毒亲缘关系最近。

Since argon is odorless, colorless, tasteless, and non-irritating, it has no warning properties.

由于无嗅、无色、无味、无刺激性，氩没有警告性特征。

Being odorless, colorless, tasteless, and non-irritating, nitrogen has no warning properties .

由于无嗅、无色、无味、无刺激性，氮没有警告性特征。

Being odorless, colorless, tasteless, and non-irritating, helium has no warning properties.

由于无嗅、无色、无味、无刺激性，氦没有警告性特征。

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。