均方根

Calculation examples of the frictional base isolation system and the hysteretic-friction base isolation system are presented, and the root-mean-square displacement, velocity and absolute acceleration responses of the former systems are compared with those of the latter system.

给出了摩擦基底隔震系统和滞变-摩擦基底隔震系统的计算实例，并对这两种隔震系统的均方根位移，速度和绝对加速度反应进行了比较。

The observational and calculated results are well matched. The calculated mean diameter, mean square-root diameter, mean cube -root diameter and liquid water content are all well matched with the observational results; In the paper two examples have been analyzed by using the seeding region data and the possible affecting region data in leeward region. It is found that F-100, 2dc, and 2dp's particle concentrations increase in leeward region, but rising extent is different, which is likely to be due to difference of seeding effect time.

拟合值和观测值吻合的较好，计算出的平均直径、均方根直径、均立方根直径和粒子浓度与观测值也比较吻合；本文对两组个例的催化影响区域及可能采集到相应值的下风方区域进行了分析，催化下风向影响区的F-100、2DC、2DP的粒子浓度比背景值都有所增加，但是增加的幅度不同，应该是催化响应时间的原因。

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。

Under the condition of running on the hard soil pavement with the total train mass, the riding comfort tests of the tractor-trailer combinations with the stiff and the flexible drawgear have been performed, and the dynamics longitudinal force has been studied. When the flexible drawgear was used, the theoretical results and the experimental data showed that the peak value of the dynamics longitudinal force, the peak value of the RMS of the dynamics longitudinal force, and the PSD both of the dynamics longitudinal force and of the longitudinal acceleration decreased largely.

以平稳随机路面激励状况下满载行驶作为挂接车辆的经常行驶工况，进行了挂接车辆以刚性牵引架及不同柔性牵引参数的柔性牵引装置牵引运行时的平顺性试验，柔性牵引理论分析结果与试验结果均表明，使用柔性牵引参数值接近优化值的柔性牵引装置后，动态纵向牵引力的峰值、功率谱密度峰值及均方根值均有了大幅度的降低；主车和挂车的纵向振动加速度功率谱峰值也有了很大的降低。

Prediction results of indepe ndent and dependent samples show that the RMS errors of SSTA predicted in 10～12 months ahead are smaller than SSTA mean square deviation and that the relative e rrors in 5 months ahead are less than 50%.

经检验，对于非独立和独立样本，预报的均方根误差分别在12个月和1 0个月预报时效内小于SSTA的均方差，相对误差在5个月预报时效内都小于50％。

For total absorption coefficient at 443 nm (a443), the root-mean-square-error is 0.046 in the South China Sea, with an averaged percentage error of 7.9%, and averaged error in log scale close to 0. For coastal waters off Fujian, RMSE, an averaged percentage error and δ are 0.194, 30.6%, and -0.167, respectively.

对于443 nm的总吸收系数（a443 ），南海的对数均方根误差为0.046，平均相对误差为7.9%，对数平均偏差为0；福建沿岸水体的对数均方根误差为0.194，平均相对误差为30.6%，对数平均偏差为-0.167 。

To reduce or remove size effect, the size classification elimination method, volume average method and normalization method based on volume were presented and the calibration and prediction results indicate that these three methods could reduce or remove the size effect effectively. The normalization method is more suit to in-line application and obtained better calibration and prediction results with the r of 0.789, 0.858 and 0.947, the RMSEC of 0.596, 0.499 and 0.313, and the RMSEP of 0.606, 0.686 and 0.413 than the results without normalization with the r of 0.716, 0.793 and 0.848, the RMSEC of 0.678, 0.592 and 0.515 and the RMSEP of 0.825, 0.764 and 0.714 for the original spectra, the first derivative spectra and the second derivative spectra with soluble solids content using partial least square method , respectively. 4. Owing to much thick skin of watermelon, contrast experiment was conducted in skin-peeled watermelon and intact watermelon to compare the influence of skin on spectra.

针对西瓜果型大且差异显著的特点，研究果型差异对可见／近红外光谱以及建模与预测结果的影响，并提出三种方法消除或减小这一影响因素，分别是分级消除法、体积平均法和基于体积的正则化方法，其中基于体积的正则化方法，更适合在线生产应用，该方法使果型大小差异明显样品的原始光谱、一阶微分光谱、二阶微分光谱在对可溶性固形物含量检测时，采用偏最小二乘法的建模与预测结果由原来的校正相关系数r分别为0.716、0.793、0.848提高到r分别为0.789、0.858、0.947，均方根校正标准偏差RMSEC由原来的0.678、0.592、0.515分别降为0.596、0.499、0.313，均方根预测标准偏差RMSEP由原来的0.825、0.764、0.714分别降为0.606、0.686、0.413； 4。

In view of the performance of the spreading sequences for spread～spectrum communication system, the performances on auto～correlation, cross～correlation, even and odd cross～correlation, mean square root of auto～correlation's side～lobe, mean square root of cross～correlation and balance of the new sequences were analyzed.

对一种新型的渐进理想的混沌映射模式，从扩频通信对扩频序列的要求出发，详细分析了该映射产生的混沌序列的自相关、互相关特性，偶互相关、奇互相关特性，以及自相关旁瓣均方根\，互相关均方根和平衡性。

Prof. Long-Ruilin mentioned that if we want to study weighted inequalities for martingales, such as the maximal inequalities, the inequalities for the square operator and so on, the condition imposed on weights are mainly A〓 and S, but we don't know whether this condition is superfluous in all problems we consider. Since the condition can not be weakened for the known operators, now we consider a new operator to discuss its L〓-boundedness, then another problem arises, under what condition can we get it?

龙瑞麟先生曾经提到要讨论关于可测的鞅的极大算子、均方根算子以及条件均方根算子的L〓有界性，或它们之间的〓有界性时，所设的主要条件是A〓与条件S，有了这两个条件在讨论加权问题时基本上没有什么困难，但是要想用更弱的条件来代替它们，即使在古典情况下（此时S条件是自然满足的）也恐怕还不到时候。

The previous researches have been done experiments mostly in the Water tank. In order to simulate turbulence of flow in river and research its characteristics, the characteristics of turbulence are studied by experiments in the water channel with ADV technique. The research results indicate that R.M.S. velocity linearly relates to the oscillating-grid frequency; R.M.S. velocity decays by power exponent relates to the distance from the grid midplane; and the relationship between the geometrical factors and the free movement space of water is direct proportion.

以往研究大都在水箱中对振动格栅紊流特性进行实验研究，为能模拟天然河道中的紊流，研究天然河道中紊流特性，利用ADV技术在水槽中对振动格栅紊流进行了实验研究研究结果表明：均方根速度与格栅振动频率成线性关系；均方根速度与距格栅中平面的距离成幂指数关系衰减；几何系数与水的自由运动空间成正比关系。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。