总体参数

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。

In Gregory scheme, not only the importance of the moist static energy is taken into account, but also the common difficulty of the moist convective adjustment scheme, the determination of the temperature profile, is obviated. At the same time, it can give the vertical profile of the apparent heat source Q〓 and apparent moisture sink Q〓. Gregory scheme has the clear physical image that includes the cumulus updrafts, cumulus downdrafts,cumulus induced subsidence in the environmental air, entrainment,detrainment and evaporation. In addition, the interaction between the cumulus and the environment is described by one-dimensional bulk model. It is simpler than the Arakawa-Schubert scheme and has no difficult to decide the spectrum of clouds accurately.It is propitious to operational use because of its simple calculation. Finally, Gregory scheme is not only suitable for moist convection of all types, but also for dry convection.

在该方案中，既强调了湿静力能能量的重要性，又回避了给定临界温度廓线的困难，并且还能给出真实的视热源Q1，视水汽汇Q2的垂直廓线；同时Gregory方案又具有很清晰的物理图象—积云中的上升运动，下沉运动，环境中的补偿下沉运动，以及卷入，卷出和蒸发等；此外，Gregory方案用总体云群模式来描述云与环境的相互作用，比型积云参数化方案简单，它避开了型方案中云谱需要精确设置的麻烦问题，计算容易，简便；最后，Gregory方案在湿对流中适用于浅，深，中不同的对流深度，并且也适用于干对流过程。

Based on the theoretical analysis and experimental studies, structural and operational parameters for the dielectric separator were determined.

通过理论分析与试验研究，确定了棉种介电选种机的总体结构及参数。

When it comes to the non-parameter density estimation technique for characterizing the region feature distribution, it also takes the collective distribution into consideration because of inaccurate segmentation.

此外，在应用非参数密度估计技术来构造语义类的特征分布时，针对区域分割的不精确性，该文还考虑了区域特征空间的总体分布因素，进而对区域的后验分布进行更可靠地估计。

This article first determines major component's structure pattern and the main design variable; Then the reference similar driving axle's structure, determines the overall project design; Finally to the host, the driven bevel gear, the differential device circular cone planet gear, the rear axle shaft gear, the full floating axle and the integral-type bridge shell's intensity carried on the examination as well as has carried on the life examination to the supporting bearing.

本文首先确定主要部件的结构型式和主要设计参数；然后参考类似驱动桥的结构，确定出总体设计方案；最后对主，从动锥齿轮，差速器圆锥行星齿轮，半轴齿轮，全浮式半轴和整体式桥壳的强度进行校核以及对支承轴承进行了寿命校核。

For designing modern gyroplane with jump takeoff capability, the characteristics of thrust/lift system parameters are investigated, and a multiobjective optimization method is presented.

对自转旋翼飞行器推/升力系统参数进行了特性分析和多目标优化设计，解决了具有跳飞性能的现代旋翼机总体方案和系统设计难题。

Sensor and controller inconstantly demand on combination kind and working parameters of data acquisition module in many moni2 toring and control systems design.

本文采用MCS51 单片机为控制器，给出了控制采集端口的组合方式及工作参数可以根据现场传感器件的要求来定制现场数据采集模块的总体方案设计。

In Chapter2 and Chapter 3, the writer introduces the basic principles of the above-mentioned four modules, simulates and demonstrates the four function modules respectively with accordance to certain parameter, and concludes the simulation result. In the fourth chapter we discussed methods of compiling ADSP assembly files and LDF files, described an actual example detailedly. And finally in Chapter 5, the realization of signal processing system is detailed described. The writer also introduces the concerning system frame, program flowchart and the experiment result according to the general indicatrix.

文章首先在第二、三章详细叙述了各模块的基本原理，按一定的参数对各功能模块进行了方案论证及仿真，并给出了仿真结果；在第四章介绍了ADSP 芯片的集成开发环境――VisualDSP++3.0 和软件开发流程，详述了具体的汇编程序实例；最后在第五章叙述了信号处理机的具体实现，按总体指标给出了相应的实现框图、程序流程图以及试验结果。

Answer: t3212 is the periodic location update time parameter that is used to force the mobile station to initiate a location update request to the network after this timer expires.

答：t3212 是周期性位置更新时间参数，用来强制移动台在该定时器逾时后自动向网络发起位置更新请求。T3212 越小，网络的总体性能就越好，但频繁的位置更新有两个负作用：一是会使网络的信令流量大大增加，对无线资源的利用率降低。

Design of a high quality and multifunction airplane electrical parameter testing system based on high speed data

论文首先对设计参数与指标进行分析，在分析结果的基础上提出系统设计的总体方案

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。