实际地

Like an index, this book does not summarize or inclusively represent, but rather points to or "indicates" a cross-fertilization of ideas between theory and practice and between education and the world of making.

就像一般索引的一样，这本书并不是在总结或是做归纳性地陈述，而更多的是指示和提纲挈领，简要地"点"出在理论与实践，学院教育与实际建造交叉过程中产生的想法。

Second, legal coordination of reasonable structure of social distribution mainly include the relation among state, enterprise and residents, the relation of distribution between center and territory and relation of crosscut distribution.

在经历了20余年的改革发展，社会经济生活已发生根本性变化的今日中国，国民经济的快速增长和社会财富总量的迅速增加，并没有实现全体国民社会福祉的普遍提高，人们实际面对的却是经济总量增长下的城乡居民收入差距的进一步扩大、社会弱势群体的基本生存需要面临严重困境、地区间社会经济发展的严重不平衡等一系列的社会分配的不公平问题。

According to the connective relationship between crunode and other graphic element,a network topology algorithm for short circuit calculation is obtained,which describes the distribution network topological structure exactly and generates the data nec...

该算法不仅能够准确地描述配电网络拓扑结构，还能生成短路计算所需的数据。在实际系统运行中表明，该算法具有一定的实用价值。

This paper discussed several methods of the evaluation on total cumulative pitch error of gear: diagram, tabulation, coordinate conversion.

齿距累积误差是影响齿轮传动准确性的重要检测项目之一，利用计算机方便、快捷地处理测量数据在工程中具有实际意义。

The problem of water leakage from curtain for cutting off water is reasonably solved after the conception of apparent connection width and construction method of big connection width in curtain for cutting off water in deep-mixing piles are proposed from practical engineering need. The economical benefit of the construction method of big connection width is better than that of construction method of traditional connection width.

6从实际工程需要出发，在深层搅拌桩止水帷幕中提出了视搭接宽度的概念和大搭接宽度设计施工方法，较好地解决了止水帷幕中桩间开叉漏水的问题；大搭接宽度施工方法与传统搭接宽度施工方法相比，还具有较好的经济效益。

In this paper, a three-dimensional multi-level hydrodynamic model with curvature correction in curvilinear coordinates has been developed based on the update turbulent theory and numerical method, which can effectively solve the practical problems of flows and water quality transportations in hydraulic engineering, and can strengthen the practical usage of the mathematical model.

本文基于现代紊流理论、现代数值计算方法建立适合描述水利工程中紊流规律的非线性数值模型，即曲线坐标系下的多层紊流水动力模型，旨在提高紊流精细模拟的实用性，以求有效地解决水利工程中的水流和输运现象的实际问题。

We learn to dam up our anger when we are dependent on any social system in which our needs and our experiences are ignored .

我说"似乎"是因为虽然我们都曾遇到过那些无力建设性地处理愤怒的情况，可实际真是那样的情况少之又少。

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。

With indefinite noises and nonlinear characteristics, real-time estimating states of the dead reckoning unit is much more difficult than that of the other measuring sensors, which used in vehicle integrated navigation systems.

由于噪声的不确定性和自身的非线性特征，通过航位推算系统精确地估计车辆的状态是实际车辆组合导航中最困难的部分。

This dissertation complete all the steps of the design and implement of decimator, and prove the possibility and flexibility of using FPGA to realize decimator both in theory and in practice.

本文完整地完成了抽取器的设计和实现过程，从理论到实际硬件一步步验证了FPGA技术应用于抽取器的可行性及灵活性。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。