角分布
- 与 角分布 相关的网络例句 [注:此内容来源于网络,仅供参考]
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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。
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We derive the ellipticity and position angle of Abell 2199, and our result coincides remarkably with those in previous studies which are based on the data from a very small core region (~30) to a very large area (~5.5°).
将我们的结果与Rines等人研究的Abell 2199的引力内流区域X-ray群的空间分布椭率和方位角进行对比,发现这些星系团基本在同一条直线上,且空间分布方位角基本相同。
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The main research work of this paper are focused on following areas:(1) Based on review of the theory and methods on measurements of particle fields, a new idea for obtaining particle size and velocity distribution within a spray through imaging the particle field with a laser light sheet was put forward;(2) A DPIV (Digital Particle Image Velocimetry) system, is fit for velocity measurements of low speed flows, was developed and expended to particle size distribution measurement;(3) An arithmetic for particle velocity field reconstruction was developed, and the velocity distribution of water mist was also obtained;(4) A software system for particle analysis, which based on image geometry emend, de-noise and image partition was developed, the parameters such as particle size distribution, mean diameter, number of particles, minimum and maximum diameter can be got with this system;(5) A water mist system was developed and its characteristics, such as droplet velocity, size distribution, number of droplets and spray cone angle under different conditions were obtained from experiments with PIVS;(6) The measurement results of water mist characteristics with PIVS were compared and analyzed with the simply simulated results, and in addition, in order to verify the accuracy of PIVS, some experiments were conducted with the standard particles, such as glass-ball with known mean diameter of 50μm and 115μm, metallic coated tracing particle with mean diameter of 12μm;(7) Some experimental studies on interaction of water mist with liquid pool fires were conducted.
本论文的主要工作包括以下几个方面:(1)在对粒子场测量的相关理论和具体方法进行综述分析的基础上,提出了通过采用激光片光对粒子场进行成像以获取其粒径和速度等参数分布的新思路;(2)研制了适宜于低速流动速度场测量的DPIV(Digital Particle Image Velocimetry)系统,并使其实现了对粒子场粒径分布的测量功能;(3)研制了基于粒子运动轨迹的速度场重建算法,获取了细水雾雾场的速度分布;(4)研制了基于几何校正、去噪、图象分割等图象处理方法的"粒度分析软件系统",该系统既可分析给出粒子场的粒径分布直方图和平均粒径,还可给出粒子的数目以及最大、最小粒径等信息;(5)建立了一细水雾发生系统,并应用上述方法对不同压力条件下细水雾系统的雾场特性(如速度分布、雾滴粒径分布、雾滴的数目、喷雾张角以及雾化长度等)进行了实验测量研究;(6)对细水雾特性参数的PIVS测量结果与计算机简单模拟计算结果进行了定性比较分析,并利用平均粒径为50μm和115μm的玻璃球以及12μm的标准示踪粒子对PIVS系统的粒径和速度测量结果进行了实验验证,同时对其局限性进行了分析讨论;(7)对不同工况条件下细水雾与油池火相互作用的过程进行了模拟实验研究。
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In virtue of Fluent of CFD software, we carry though computation of aerodynamics of an air-to-air missile in different Mach meter and different attack angle and gained movement trend of lift coefficient、drag coefficient and pitching moment coefficient with variety of Mach number and attack angle, meanwhile, we also obtain distributing trend of pressure, temperature and weather velocity.
借助于商业CFD软件FLUENT,对某型空空导弹在不同攻角、不同飞行马赫数的气动力进行了计算,得出了该型导弹升力系数、阻力系数和俯仰力矩系数随飞行马赫数和攻角的变化规律以及导弹表面的压力分布、温度分布和来流速度分布。
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With this method a model of the large offset, highly compact intake is made and tested meticulously at low and high speeds. In the paper the distribution of the total pressure at the exit section and the static pressure along the wall of the intake is given at low speed, and the performance of the intake has measured at different Mach numbers, incidences and yaws.
并借鉴S形进气道的设计方法完成了高偏距、短扩压埋入式进气道的设计,并对该埋入式进气道的高、低速性能做了细致的研究,给出了0.1马赫数下进气道出口截面上的总压分布、总压畸变、壁面静压分布,以及0.5~0.8马赫数范围内,该进气道模型在-7°~10°攻角范围和8°侧滑角范围内的性能。
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The location and structures of sex-pheromone-producing gland in female H.insularis were studied by EAG,GC,SEM,and TEM.These studies showed that thegland situate in the intersegmental membrane between the eighth and ninthabdominal segments,and is an eversible abdominal fold;Many plump cones disturbon the surface of the gland.The glandular cells of 2-day old virgin female H.insularis are arranged in one layer,among which the central cells are columnarepithelial cells and flat on two sides.The nucleus is irregular elliptical.There isevident conjugation between cells and the involution is more in the basal membraneof cell.Microvilli are distributed on the cytoplasmic membrane and linked withendocuticle on which there are many layers of chitin,and the outer cuticule is staineddeeper.The cell contains bubbles,mitochondria,glycogen deposits,roughendoplasmic reticulum and smooth endoplasmic reticulum.
结合触角电位、毛细管气相色谱、扫描电镜、透视电镜等技术对小线角木蠹蛾雌蛾腹尖末端不同组织部位提取物的测定分析以及腺体位置和形态结构的观察发现:小线角木蠹蛾性信息素分泌腺位于腹部末端8~9节之间,是一个由节间膜特化而成的上皮结构,为一可外翻的腹褶,腺体表面分布着饱满的锥形体,羽化后2天未交尾的雌蛾腺体细胞呈单层排列,腹面中央由密集的柱形上皮细胞组成,细胞排列向两侧延伸至背部,其形状由柱形逐渐变为扁平形,细胞核为椭圆形,细胞与细胞间有明显的胞连接,细胞基底膜基褶较多,质膜上分布着微绒毛,并与内表皮连接,内表皮上有多层几丁质,外角质层染色较深,细胞质中含有空泡、线粒体、脂质粒、粗面内质网和光面内质网。
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the title compound was synthesized and its structure was studied in theory.the schiff base compound was synthesized by condensation of paeonol with furylfurylamine,then it was deoxidized by sodium borohydried.the energies,bound lengths,bound angles,the net charges of main atom and contributive percents of frontier orbital in the title compound have been calculated by software hyperchem 7.0 in half experience method.the yield rate of title compound was 65.6%.the result of calculation showed that the most of the bond lengths and angles in the system were in the the normal range,negative charge mainly concentrate on o1,o2,o3 and n1.the title compound behaves as quadridentate ligand.
目的合成标题化合物并对其结构进行了理论研究。方法以丹皮酚和糠胺为原料合成席夫碱,经硼氢化钠还原得标题化合物;使用hyperchem7.0程序,用半经验方法计算了化合物分子中能量分布、主要键长、键角以及主要原子的净电荷分布和前言轨道分布。结果标题化合物,收率65.6%;计算结果分析表明,分子中主要原子之间的键长、键角基本在正常的范围内;负电荷主要集中于o1,o2,o3和n1上。
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The main content included in the paper is as follows: The European identification methods of type of wave load is introduced and compared with the methods in Code of Hydrology for Sea Harbour. In order to reveal their difference, they are tested by the experiment data. The relation between phase and frequency are analysed through the Hilbert and wavelet transformations. And a new method of identifying the breaking wave load is set up based on the linear relation between wave height and wave press before the breakwaters. The probability distribution is tested by the statistic of experiment data. Based on the experiment data, the paper analysed the influence of reflection coefficient according to different factors, and its property is got. The work property of charmfered breakwater under breaking waves is analysed. Through the statisticof its wave press and wave force the distribution of press on the breakwater front face and its reducing effect to breaking wave force are proved.
本文基于此,通过实验研究,主要作了如下工作:介绍了欧洲波态划分方法,分析与我国方法的异同,通过实验进行了验证;通过 Hilbert 变换和小波变换对波浪破碎的相频特性进行了分析,通过建立波高与波压关系来判别破碎波浪力;对破波条件下波浪力的分布进行了统计研究,验证了其分布类型;利用实测资料,分析了不同因素对反射系数的影响,得出了不同周期、波浪要素、破碎率下反射系数体现的不同规律;分析了破碎波作用下削角堤的工作特性,通过对堤面所受的波压力和总力的统计分析,验证了压强分布规律及削角堤对波浪力的削减作用。
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This problem is also important and valuable in Nonlinear Optics. It will be very helpful to understand how the aberrations affect the course of three- wave mixing, such as the change of conversion efficiency, the distribution of intensity and phase.Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental waves aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.
首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解;通过建立国防科学技术人学研究生院学位论文三维数值模型,编写相应仿真程序,首次得到了位相畸变光束倍频过程的大量计算结果,深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素;得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同,但谐波的远场发散角明显地比相应基波的小的结论;得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下,位相畸变传递到二次谐波的估算式;举例分析了KDP三倍频方案中,基波位相畸变对二次谐波和三次谐波的影响;实验工作中,用哈特曼一夏克传感器分别对IO64nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量,给出了相应结果。
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Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental wave's aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.
首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解;通过建立三维数值模型,编写相应仿真程序,首次得到了位相畸变光束倍频过程的大量计算结果,深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素;得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同,但谐波的远场发散角明显地比相应基波的小的结论;得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下,位相畸变传递到二次谐波的估算式;举例分析了KDP三倍频方案中,基波位相畸变对二次谐波和三次谐波的影响;实验工作中,用哈特曼-夏克传感器分别对1064nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量,给出了相应结果。
- 推荐网络例句
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The concept of equivalent rotationally rigidity is offered and the formula of rotationally rigidity is obtained.
主要做了如下几个方面的工作:对伸臂位于顶部的单层框架—筒体模型进行分析,提出了等效转动约束的概念和转动约束刚度的表达式。
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Male cats normally do not need aftercare with the exception of the night after the anesthetic.
男猫通常不需要善后除了晚上的麻醉。
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Its advantage is that it can be used in smaller units.
其优点在于可以在较小的单位中应用。