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By means of analyzing the noise error, it is proposed to use an algorithm of singular value decomposition total least squares to conduct the interharmonics estimation, namely taking the noise interference at both sides of the matrix equation into account simultaneously and solving the minimum norm problem by least square method under such condition. In the proposed algorithm by means of singular value decomposition of a new augmented matrix and by use of a simple and practical method to determine the number of principal singular value related to signal to noise ratio, the storage calculation of right singular matrix is performed, thus a more accurate frequency estimation of interharmonics can be obtained.

通过分析噪声误差,提出采用奇异值总体最小二乘(singular value decomposition total least squares,SVDTLS)算法进行间谐波频率估计,即同时考虑矩阵方程两边的噪声干扰,采用SVDTLS算法求解该情况下的最小范数解,通过对增广矩阵进行奇异值分解(singular value decomposition,SVD),采用简单实用的与信噪比相关的主奇异值个数确定方法对分解的右奇异矩阵进行存储计算,得到了较精确的间谐波频率估计结果。

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。

Also, by contrasting the daily、 mensal and annual precipitation interpolation errorrespectively between SIA and the other methods, we know that the interpolation effect of SIA is better than others, and its accuracy is preferable in the mass.

并且,对用逐步插值法得到的年降水量、月降水量以及日降水量误差分别与用其他方法得到的误差对比可知,总体上看,逐步插值法的插值效果较好,精确度较高。

Of endogenous variables with the Root-Mean-Square Percent Error between simulated values and actual values less than 5%, and 81. 8% of endogenous variables with RMSPE less than 10%, which implies that the overall goodness of the model is satisfactory.

检验结果表明,动态模拟值与实际观测值的均方根相对误差低于5%的内生变量占全部内生变量的59.1%,而均方根相对误差不超过10%的内生变量占81.8%,说明模型对观测值具有良好的总体拟合性能。

In this article,students actually present at exams are regarded as simple random sampling of all the students,and the sampling and assessing ways are applied.

将实考考生看作为考生总体的一个简单随机样本,应用抽样估值的方法,在若干合适的概率分布模型下,收集和推演了考生总体合格率的一些估计公式,以估计有考生缺考时,考生总体的合格率。

On the base of other researcher, the *** from the basic equations of stable current field to derived the expressions of boundary problems under 3-D condition. Without considering the EM effect and using the generalized variation principle, we can get the corresponding variation equation. Thronging subdivide the 3-D model, interpolation, analysis, and general synthesis with the triangular prism element, we can carry out the simulation on frequency-domain IP\'s parameters under level and undulate topography.

在前人工作的基础上,在忽略电磁效应的情况下,从稳定电流场的基本方程出发,推导了三维区域满足的边值题目,用广义变分原理得到相应的变分题目,通过用三棱柱单元对大地模型进行剖分、插值、总体集成,最后解方程,得到每个节点上的复电位值,最后实现了水平和起伏地形等条件下的激电参数的数值模拟。2。

Using nuclear DNA C-values for 539 angiosperms in China, we examined the variation of these values among growth forms and taxonomic groups and the relationship of these values with invasiveness. Mean DNA C-value of the 539 angiosperm species was 4.06 pg. Mean DNA C-value was(1) significantly lower for woody species (1.84 pg) than for herbaceous species(5.02 pg);(2) significantly lower for 360 dicots (2.20 pg) than for 179 monocots (7.80 pg);(3) significantly lower for annuals (2.78 pg) than for perennials(6.65 pg);(4) significantly lower for 134 weed species (1.93 pg) than for herbaceous non-weeds (6.75 pg) and for several families that have an unusually high proportion of weed species;(5) significantly lower for 47 exotic weed species (1.76 pg) than for 134 native weeds (1.93 pg), but significantly lower than that of "non-weedy" herbaceous species (6.75 pg);(6) lower for weeds than for "non-weedy" species in same genus or family; and (7) in herbaceous species, generally lower for weedy compared to "non-weedy" species, with some exceptions such as Avena fatua, whose DNA C-value is as high as 14.15 pg, contrarily, and some "non-weedy" herbaceous species in Cruciferae and Cucurbitaceae with very low values.

统计了中国境内有分布的539种被子植物的DNA C-值,分析了它们在不同分类群、生活型、倍性、生活史类型以及在杂草和非杂草类群中的分布情况,主要结果如下:(1)539种被子植物DNA C-值平均为4.06 pg,其中木本植物的DNA C-值平均为1.84 pg,低于草本植物的平均值(5.02 pg);(2)双子叶植物(360种)的DNA C-值平均为2.20 pg,极明显地小于单子叶植物(179种)的平均值(7.80 pg);(3)1年生植物的DNA C-值平均为2.78 pg,明显小于多年植物的平均DNA C-值(6.65 pg);(4)134种杂草的DNA C-值平均为1.93 pg,明显小于非杂草草本植物的平均值(6.75 pg),含杂草较多的科,平均DNA C-值相对较小;(5)统计的47种入侵杂草的DNA C-值平均为1.76 pg,略小于134种杂草的平均DNA C-值(1.93 pg),极显著地小于非杂草性草本植物(6.75 pg);(6)以科为单位,不同科的DNA C-值存在着极大的差异;(7)DNA C-值与染色体倍性的关系并不明显,但是,随着倍性的增加,基因组变小;(8)在同一科、属中,与非杂草相比,典型杂草的DNA C-值往往偏小;(9)总体上杂草或杂草性强的植物,它们的DNA C-值比非杂草性植物的要小。

The valuators send the bid information to the resources entities,whether the resources entities bid according to the bid information,if the valuators receive bid applications sent by the resources entities,than they just only research trusted entities in the resources entities that they have send the bid applications,than the valuators sign the contract with the resources entities which accord with the conditions.

首先由评估者向资源实体发出招标信息,资源实体根据招标信息投标或不投,评估者收到资源实体的投标申请书,就只需在已发投标申请的资源实体中进行信任查找,然后与符合条件的资源实体签订合约;在信任更新机制中将推荐行为发生后总体信任值作为较真实的信任值,与中间实体推荐信任值比较,根据二者的误差生成反馈,调整对此实体的信任度。

In the space, along with increased distance from the main ore-controlling structures, the frequency of P type of pyrite and their thermoelectricity also decreased gradually. Within one lode, from the upper to the lower parts of an ore body, the vertical change of pyrite in thermoelectricity as the follows:① when the ore body is stable, that is when the ore body is uniformly and continuously mineralized, the Dp andαvalues keep increased from shallow to deeper parts;② when an ore body is discontinuously mineralized, the Dp andαvalues have a wavy increasing tendency from the shallow to the deeper;③ when the deeper part of an ore body contains abundant, Co and Ni high mafic dykes, the Dp andαvalues of pyrite decreased from the shallow to the deeper parts of an ore body, that is, an reversed zoning of pyrite thermoelectricity occurs for pyrite in this situation contain more Ni and Co and belongs to N type.④ For the deposits hosted in the Archean metamorphic rocks, because all of the pyrite in this case is N-type, the vertical change of pyrite is not featured by the transition of pyrite type, but by the increased values of Vnp and α from the shallow to deeper parts of an ore body.

在空间域上,水平分带规律为:随远离主干断裂,矿脉中P型的出现频率逐渐降低或热电系数值逐渐变小;在同一条矿脉中,这是由于矿化不均匀性及脉岩的影响,由矿体的上部到下部,它的垂向变化特征可以有如下几种变化形式:①由矿体的浅部到深部,黄铁矿的Dp值、或α值呈稳定升高的趋势时,矿体往往表现为矿化均匀,连续性好、延伸稳定;②由浅部到深部,黄铁矿的Dp值、α值呈波状变化,但总体又具有增大的趋势时,所在的矿体连续性差;③当矿脉的下部发育有大量的基性脉岩时,由于基性脉岩中常含有较高的Co、Ni,使其中黄铁矿的Co、Ni含量较高而呈N型导电,由矿体的上部到下部,黄铁矿的Dp值、α值呈减少的趋势,而造成黄铁矿热电性特征的逆向分带,④产于太古代变质岩中的中深脉状金矿,由于其中的黄铁矿均为N型导电,所以垂向变化规律并不表现为导型的改变,只是Vnp值或α值从矿体的上部到下部由小变大。

The results show that (1) the flow volume angle A50 is a reliable parameter for the diagnosis of MEFVC;(2) the flow volume angle A75 has the best sensitivity for early detection of small airway dysfunction;(3) we also establish the normal predicted equations of pulmonary function testing for the adult Chinese in Taiwan area.(4) length of arm span and sitting height are reliable indices to predict body height for the calculation of normal pulmonary function data.

结 果显示:流量容积角A50 可当作用力呼气流量容积图形之总体肺通气功能检查的诊断指标;流量容积角A75 对早期小呼吸道之功能不彰具有侦测的功能;本研究亦建立了在台湾地区之成年中国人的正常肺功能预测值公式,以供参考用;量取手臂侵与生高之值确可用来推测身高值。

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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。

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。

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。。。。。。