查询词典 axial flow

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 general, the design work with traditional measures is done by hand, which cannot meet the needs of the technology and manufacture. So the author has developed a CAD hydraulic design software fit for lower specific speed axial flow runner, which is easily operated by users.The main research work of this paper is as follows:1 Analyzing the main reason of axial flow power station cannot work well under littler volume of flow in some season and putting forward an improving scheme, pointing out the characters of design under abnormal factors.2 Combined with the development of the industry in our country, the abnormal hydraulic design method of propeller turbine is discussed based on present literature, data and experiment results.3 Guided by the design method of software engineering, a suit of hydraulic design software of Lower Specific Speed Axial Flow Runner is programmed by the object-oriented programming language Visual Basic and a straightforward, concise and standard Windows human-computer dialogue interface is designed for the system, which makes the operation of the system very convenient.4 ActiveX Automation technology is adopted as the interface with AutoCAD and the hydraulic drawings are edited, modified by AutoCAD until hydraulic model drawings according with the demand of engineering practice are output.5 To resolve practice problem, the author has designed a lower specific speed axial flow runner for Duowa Power Station through an example.

论文的主要内容有：1 深入分析很多轴流定桨式水电站枯水季节小流量下不能发电的主要原因，提出减容改造方案，并指出超常规条件下的改造设计特点。2 结合国情及行业发展需要，参考现有资料、文献和前人的研究成果，进行低比转速轴流式转轮叶片水力设计方法的研究，对轴流式转轮叶片的奇点分布法水力设计进行了全面的探索，结合现代计算机技术，找到了一种针对特殊条件的轴流式转轮叶片水力设计方法。3 仔细比较多种AutoCAD二次开发工具后，结合本课题的特点，选用Visual Basic语言，综合应用软件工程的设计思想，进行低比转速轴流式转轮叶片水力设计软件的编制，为系统设计了直观、简洁和标准的Windows人机对话界面，便于用户操作；编程时在考虑到设计条件特殊性的同时，尽量做到程序的通用性，使之可用于解决同一类问题；另外，大部分程序还可移植到普通轴流式转轮叶片水力设计中，具有良好的适应性。4 利用ActiveX Automation技术与AutoCAD接口，对AutoCAD进行二次开发，在AutoCAD下实现水力图的自动生成和编辑，直至输出符合实际工程要求的木模图。5 通过算例，为多哇水电站设计了一个低比转速轴流定桨式转轮，解决其在枯水期小流量下不能发电的问题。

The structure of this article is as follows: Firstly, the background of this article is stated in exordia and the question was raised; chapter one stated cash flow management theory and transnational corporations' cash flow management characters; chapter two introduced general cash flow management technical and method; chapter three analysis cash flow management situation of Chinese transnational corporations; chapter four take VW as an example to expatiate company situation and the impact to cash flow management by the organization of the company, the goal of cash flow management and financing strategy, then introduce the cash flow forecast module, at last analysis the experience and disadvantage of VW's cash flow management; Chapter five give some suggestions to Chinese local transnational corporations for cash flow management including: using proper cash flow management technical and establish scientific process, ect.; the last part is the conclusion This article took VW's cash flow management as an example to descried transnational corporation cash flow management theory and practical issues, but some techniques can only be used in some country where can exchange currency freely; it can not be practical in some foreign exchange administration countries including China, such kind of cash flow module still under discussion based on theory.

本文结构如下：首先在绪言部分简述了选题背景，提出了问题；之后，第一章陈述了现金流管理理论和跨国公司现金流管理的特点；第二章评述了国际常见的现金流管理技术和方法；第三章分析了中国跨国公司的现金流管理现状；第四章详细阐述了VW公司现金流管理的实例，包括公司的发展及组织架构设置对现金流管理的影响，公司现金流管理的目标、筹资策略等，重点介绍了VW公司的现金流预测模型，最后分析了VW公司现金流管理的经验和不足；第五章详细阐述了对中国跨国公司现金流管理的建议，包括应用适合的现金流管理技术及建立科学的现金流管理流程等；最后在结论部分对该文做了总结。

This thesis deals with oil-water flow rate measurement using a venturi and develops a differential pressure-based two-phase flow rate measurement model, which does a terrific job with the use of a water fraction device. Meanwhile, Coriolis flow rate meter is also studied in the oil-water two-phase flow measurement and a SVM-based single-phase flow rate prediction method is proposed, realizing the prediction of single-phase flow rates. To overcome the disadvantages of both venturi and Coriolis flow meters, a double parameter measurement method is put forward, which combines the two meters and solves the problem of oil-water flow rate measurement. Last but not least, on the basis of the study of two-phase flow, a device for the separation of gas and liquid is designed and realizes the flow rate measurement of three-phase flow as oil, gas and water.

本文对文丘里管测量油水两相流流量进行了研究，建立了基于差压法的两相流流量测量模型，如果与含水率计相结合，可以较好的实现油水两相流的流量测量；同时研究了Coriolis流量计在油水两相流流量测量中的应用，提出了基于SVM的油水两相流分相流量预测方法，实现了油水分相质量流量的预测；针对文丘里管和Coriolis测量油水两相流存在的问题，提出了文丘里管和Coriolis流量计相结合的双参数测量方法，并实现了油水两相流的流量测量；最后，在对油水两相流研究的基础上，设计完成了一种气液分离装置，实现了油气水三相流的流量测量。

We proposed a set of tabulate shim coils to improve the imaging field homogeneity for permanent magnet. By studying the magnetic spherical harmonics and its Taylor expansion, the proposal of designing lower-order radial coils was derived including x, y, xz, xz~2, x~2-y~2 etc. In addition, a novel composite design was presented for the axial coils. By controlling the shim currents of axial coils, different axial magnetic fields can be obtained. This method simplified the design process of axial coils, and made the axial correcting magnetic field more precise.

本文针对永磁体的组成结构提出了一种平板式匀场线圈设计方法，通过研究成像磁场的球谐函数以及通电圆弧在自由空间产生磁场的泰勒展开级数，导出了x、y、xz、xz~2、x~2-y~2等低阶径向线圈的设计方法，同时针对轴向线圈提出了一种新的混合式设计方案，能够通过控制线圈中的电流组合实现对不同轴向磁场分量的获取，简化了轴向线圈的设计过程，提高了校正磁场的准确性。

The turbine comprises at least one radial or diagonal turbine stage (120) with radial or diagonal feed stream and axial exhaust flow and at least one axial turbine stage (121 - 125) with a axial feed steam and axial exhaust flow.

该涡轮机包括至少一个带有径向的或者对角线的入口和轴向的出口的径向的或者对角线的涡轮机级(120)和至少一个带有轴向的入口和轴向的出口的轴向涡轮机级(121-125)。

In this paper the importation of translations that the value orientation of personnel, organization and personnel employment orientation towards the mobile space changes focusing on concepts, organizations, systems, cultural, and social aspects of China's human impact on the flow of major issues, from the political, economic, cultural, market, environment etc., the promotion and protection of the rational flow of talents to deal with comments and suggestions, as follows: In politics, setting up the political sense of talent with the progress of time spirit, implementing roundly the strategy to strengthen nation by relying on talent, establishing quickly the system to manage talent and reforming the system of personnel; In economy,talent flow corresponding with economic construction, assorting talent's structure with economic structure, paying attention to the economic benefit from talent flow, quickening to construct the social welfare system of talent, founding the flexible system of employment and reducing the cost of talent flow; In culture, stressing on the functions of culture for talent flow, cultural model corresponding with the model of talent flow, sparking plug the excellent culture to facilitate talent flow and erecting the cultural system to motivate talent flow; In marketing, unifying the thinking to developing talent market, enhancing the construction of talent market and fastening the growth of service agency for talent; In surroundings, grasping the elements of talent surroundings, optimizing the circumstance of talent flow and building the condition to look after the security of talents.

本文指出了人才价值取向、组织用人取向和人才流动空间走向的变化，着重从观念、组织、制度、文化、社会等方面具体分析了影响我国人才流动的主要问题，从政治、经济、文化、市场、环境等方面研究，提出了促进和保障人才合理流动的意见和建议，包括：树立与时俱进的人才政治理念，全面实施人才强国战略，加快构建人才领导体制，改革创新人事制度等政治对策；人才流动与经济建设对应，人才结构与经济结构协调，讲求人才流动的经济效益，加快人才社会保障体系建设，建立灵活的就业体制，降低人才流动的经济成本等经济对策；注重文化功能对人才流动的作用，倡导促进人才流动的优秀文化，构建激励人才流动的文化机制等文化对策；统一人才市场发展思路，突出人才市场建设重点，加快人才服务业的成长等市场对策；优化人才流动环境，构建人才安全环境等环境对策。

A washer has a body having an axis and provided with a first bearing face surface located at one axial side and adapted to cooperate with a nut, a second bearing face surface located at an opposite axial side and adapted to cooperate with an object, at least one third turning resistant surface adapted to cooperate with a thread of the bolt, the body having at least one resistive point arranged so that when the nut is turned and turns the bolt the body of the washer stops the bolt from turning and thereby the nut creates a pull on the bolt which elongates the bolt in an axial direction and applies to the body of the washer an axial force which overcomes the at least one resistive point so that a portion of the body of the washer is allowed to be pulled axially when the bolt elongates.

一种放在螺帽与物体之间的垫圈，螺帽与螺栓螺纹连接，螺栓插入在包括两个装配的部件的物体内，垫圈具有主体，和设有第一支承面表面，位于一个轴向侧面和与螺帽配合，第二支承面表面，位于相对的轴向侧面和与物体配合，以及至少一个第三转动阻力表面，与螺栓的螺纹配合，从而使螺帽以给定的扭矩在一个方向转动同时垫圈的主体沿相对方向接收给定的力时，仅有螺帽转动，以紧固或松开螺栓，而垫圈的主体和螺栓保持静止。

Based on theory and test, finally, the measurements which may reduce axial force are given, for example, strengthening the management of size and clearances in roll systems and maintenance of roll bearings, limiting rolling technological conditions, increasing the axial flexibility, releasing axial binding forces and establishing axial flexible lock mechanisms, etc.. So it provides the constructive suggestions for preventing from damage of roll bearings.

在理论分析和实验验证的基础上，分析了轧辊轴承的受力特点和破坏原因，提出了降低轴向力的对策，其中包括加强尺寸及间隙管理、限定工艺条件、加强轴承的维修与管理等&硬&性措施，以及增加辊系轴向柔度、施放约束、建立柔性锁紧机构等&软&性措施，为现场解决轴承损坏问题提供了建设性参考意见。

T35-11 Axial Flow- Blast Fan is a new generation product which was designed out after analyzing and comparing to the similar products abroad as well as experimenting and with model. This T35-11 Axial Flow-Blast Fan is remarkable of its high efficiency and low noise, and can be used in Industrial and Mining Enterprises, storehouses, offices and civil buildings for ventilating or facilitating heating system. The axial fan can be used as a fan when removing its housing and also can be installed in series connection inside the long exhaust pipeline to enhance wind pressure.

T35-11轴流式通风机是对国外同类产品进行分析对比，通过模型试验研究后设计的新一代轴流式通风机，具有效率高、噪声低的显著特点，可用作一般工矿企业、仓库、办公室、民用建筑内通风换气或加强暖气散热之用，若将机壳去掉，则可作自由风扇用，也可在较长的排气管道内隔串联安装以提高管道中的风压。

More direct, directer ; most direct, directest

径直的，笔直的

Do you know how to use a chain saw?

你知道如何使用链锯吗？