有分量
- 与 有分量 相关的网络例句 [注:此内容来源于网络,仅供参考]
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Thereby, these facts indicate that the SDE not only have better statistic properties but also have uniformly smaller mean square errors than ANOVAE in an available group of linear mixed models. The other significative following work is to generalize the idea of SDE to multivariate linear mixed model and obtain the SDE of variance component matrices which uniformly dominate the ANOVAE either.
对于含有一个随机效应的混合模型,目前文献中都仅讨论了方差分量的谱分解估计和ANOVA估计等价的充要条件,本文首次给出了方差分量的谱分解估计在均方误差意义下严格的优于ANOVA估计的理论结果,并推广到广义谱分解估计,从而说明谱分解估计不仅较ANOVA估计有更好的统计性质,而且在一类常用的模型下有更小的风险损失。
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A magnetic field with a constant and an oscillating components perpendicular to each other is applied.
设想在量子点上加一磁场,有相互垂直的一恒磁场分量和一谐振分量。
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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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From the perspective of minimum transmission losses, an instantaneous reactive power theory for systems with any number of phases and with or without neutral line is developed. Under the new definition, each quantity has its own physical meaning, and the zero sequence current can be decomposed into active and reactive components. Furthermore, a generalized compensation method for zero sequence current is developed.
从输电损耗最小的角度出发,提出了任意相无中性线或有中性线系统的瞬时无功功率理论,在新的理论下,每个量都有清晰的物理意义,且能分解出零序电流的有功分量和无功分量,并给出了通用的零序电流补偿方法,揭示了瞬时无功功率理论与传统平均意义下的无功功率理论的联系及本质区别,从而为研究HVDC-VSC及各种FACTS装置的无功功率控制奠定了理论基础。
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The plastic deformation induced due to cyclic rotation of principal stress axes alone can be in the same magnitude as that due to shear with fixed principal stress axes. 2 The volumetric strain due to shearing of cyclic rotation of principal stress axes is found to be composed of a reversible dilatancy component and an irreversible dilatancy component. The former is characterized by its reversibility and is independent of past shear history, the latter by its irreversibility increases with the increase of cycle number yet its increase rate decreases with its accumulation. 3 The obvious non-coaxiality between directions of the principal stresses and principal strain increments is found and its degree depends largely on the change of shear stress component. 4 The intermediate principal stress has considerable effects on the deformation behavior of sands in the condition of cyclic rotation of principal stress axes. The accumulation rate of the irreversible dilatancy component increases with the increase of the intermediate principal stress parameter.
具有初始各向异性的砂土在纯应力主轴循环旋转排水条件下的主要变形规律为:①纯应力主轴循环旋转可产生与应力主轴固定单调剪切处于同一数量级的塑性变形;②纯应力主轴循环旋转引起的剪切体变包含可逆性剪切体变分量和不可逆性剪切体变分量两部分,其中可逆性剪切体变分量在一周内可完全恢复,基本与应力历史无关;不可逆性剪切体变分量随循环周数的增加呈单调增加,且增加速率随其自身累积值的增大呈减小趋势;③应变增量主轴与应力主轴之间的非共轴现象显著,且在一周内具有分段性;④中主应力对应力主轴循环旋转条件下砂土的变形特性有重要影响,不可逆性剪切体变分量的累积速率随中主应力系数的增加而增加。
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Under the condition of not considering the local topology effect and using a simplified layer velocity structure , we obtain the following results:(1) For a vertical strike-slip fault, the stations located on the parallel side of the slip , the transvers component ground motions show faster attenuation than the radial component motions.
对垂直走向滑移断层而言,沿著与断层面走向平行分布的测站,其与断层面走向平行分量的峰值,和其他二分量相较之下,有较明显的衰减趋势;而沿著与断层面走向垂直分布的测站,其与断层面走向垂直分量的峰值,和其他二分量相较之下,有较明显的衰减趋势。
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From our result, we can see that unphysical components of the gauge fields are contributive to the vacuum energy and it just cancel out ghost fields contribution to the vacuum energy.
从计算结果来看,规范场的物理分量和非物理分量对真空的零点能都有贡献,而规范场的非物理分量对真空能量的贡献,不仅不包含M-C-S规范场的质量项,而且恰好与鬼场的贡献相抵消。
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In this paper, the functions and the fashions of regularization are discussed when traveltime tomography is reduced to the solution of linear equation system, the functions of regularization include: constraint components which are underdetermined or lie in null space using overdetermined components and all kinds of known information; treat the uneven coverage of rays and the inaccurate datas by damping.
反射地震走时层析最终可归结为线性方程组的求解,本文讨论了在线性方程组求解过程中正则化的作用和方式。正则化的作用有:(1)用超定分量约束欠定分量和零空间分量;(2)用先验信息约束欠定分量和零空间分量;(3)对射线的不均匀覆盖进行阻尼;(4)对数据的不准确性进行阻尼。
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When the digitalsignal carries on the long distance transmission, the high frequencycomponent weaken increases along with the distance increases, theelectric cable median line also advances to the betweenelectromagnetic radiation along with the frequency intensifies, thusthe clipped wave transmitting range and the transmission quality,simultaneously in the channel often also exists separates the directcurrent electric capacity and the coupling transformer, they cannottransmit the direct component and have a bigger weaken to the lowfrequency component, therefore high frequency and low frequency arepartial regarding the common channel is limited.
当数字信号进行长距离传输时,高频分量的衰减随距离的增大而增大,电缆中线对之间的电磁辐射也随着频率的增高而加剧,从而限制信号的传输距离和传输质量,同时信道中往往还存在隔直流电容和耦合变压器,他们不能传输直流分量及对低频分量有较大的衰减,因此对于一般信道高频和低频部分均是受限的。
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Based on this, aim at the disadvantage on Wigner Distribution and Fractional Fourier Transform that can't restrain noise interference effectively when be used to detect Linear Frequency Modulated signals interfered by heavy noises, we proposed a improved WD. Simulation results show that this method can restrain noise interference effectively and improve the ability of LFM signals detection. On the other hand, in multi-component cases, WD suffers from the cross-terms, which may impair some of the auto-terms. In order to separate original multi-component signals into components and reconstruct them separately, we can use the method of optimal filtering in fractional Fourier domain. But this method also has a problem that if signals have aliasing in the fractional Fourier optimal domain as well, the reconstructed signals will be distorted. In this thesis, a novel method of quasi Fourier transform is proposed in order to solve the problem of multi-component signal reconstruction, and have good results.
在此基础上,针对Wigner分布和分数维傅里叶变换在处理高噪声背景下线性调频信号检测的问题时存在不能有效抑制噪声干扰的缺点,提出了改进Wigner分布的办法,该方法能够抑制噪声,提高信号的检测能力;针对Wigner分布在处理多分量非线性调频信号时存在干扰项的缺点,以及分数域最优滤波方法在处理多分量非线性调频信号分离重构问题时存在的局限性,该局限性表现为在对最优分数域上也有信号分量重叠的情况进行处理时重构信号发生畸变,提出了新颖的类傅里叶变换的方法,该方法对在最优分数域上也有信号分量重叠的情况也能处理,得到的重构信号失真很小。
- 推荐网络例句
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With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.
随着死亡的吉他手Schuldiner接受主唱的职务,乐队在现实中树立了重要的影响。
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But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.
不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐,因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。
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Closes the eye, the deep breathing, all no longer are the dreams as if......
关闭眼睛,深呼吸,一切不再是梦想,犹如。。。。。。