本质谱

词组短语

essential spectrum

与本质谱相关的网络例句 [注：此内容来源于网络，仅供参考]

In this paper,a systematic direct perturbation method of dark solitons is found.Having analyzed the mistakes in earlier works on perturbation method for dark solitonsand essence of the direct perturbation method for bright solitons,we notice that to in-troduce the adjoint solutions of the squared Jost solutions and to prove the completenessare crucial to the problem.Giving up the unnecessary scheme of introducing the adjointoperator in the bright soliton case,we directly find the adjoint solutions by meetingthe demand for the orthogonality that inner product of the squared Jost solutions andits adjoint should be proportional to a δ function in the case of continuous spectra.The corresponding adjoint operator is thus found.Taking into account the reductiontransformation,we find a correct description for the completeness of the squared Jostsolutions and directly verify its validity with explicit expressions of the squared Jostsolutions.

本论文建立了系统的暗孤子直接微扰方法，在对前人关于暗孤子微扰方法的错误以及亮孤子直接微扰方法的本质作了充分的分析后，认识到引入平方Jost解的伴随解和证明完备性是问题的关键，撇开过去亮孤子情况首先引入伴随算子的非必要作法，直接从平方Jost解与其伴随解的内积在连续谱时正比于δ函数这一正交性要求出发，找出了伴随解，同时得出了应有的伴随算子，在考虑到约化变换性后，得到了暗孤子情况的平方Jost解的完备性的正确表述，并在单个暗孤子的情况利用平方Jost解的显式直接验证了它的正确性。

In the bounded linear operator approximation theory of Hilbert Space,the isolate point of operator essential spectrum is always a problem. In this paper,a general method to treat this problem is given.

孙辉在Hilbert空间线性算子逼近论中，算子本质谱的孤立点通常是处理一些问题的主要障碍之一，本文给出处理算子本质谱的孤立点的一般方法。

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。

Chapter 1 gives the background,current research process of relatedproblems and summarizes this thesis\'s work.In chapter 2,we study the Brownian motion with holding and jumping on the boundary.We use the resolvent method to obtain the infinitesimal generator because the domain of the infinitesimal generator is essentially the same as the range of the resolvent.Knowledge of this range and of the differential operator determines uniquely the infinitesimal generator.Since the semigroup generated by the DHJ is not strongly continuous,to use the nice property of strongly continuous semigroup in analytic theory,in chapter 3 we show that the dual is strongly continuous and derive ergodicity through spectral radius formulas and finally obtain the ergodic theorem by duality. In chapter 4,we discuss a class of a more general process---one dimensional Feller diffusion proposed by W.Feller in 1954.The Feller diffusion allows the possibility of jumps from boundary to boundary,not only from boundary to the interior.We give the stationary distribution of this process.

具体地，本文的结构如下：第一章给出了问题产生的背景，研究现状及本文的主要工作；第二章研究了在边界上逗留后随机跳的布朗运动，我(来源：3dABC论文网www.abclunwen.com)们用预解算子的方法得到其无穷小生成元，因为无穷小生成元的定义域本质上就是预解算子的值域，知道这个值域和微分算子形式就能唯一地决定无穷小生成元；由于DHJ过程产生的半群不是强连续的，为利用强连续半群的一些漂亮性质，在第三章中我们证明其对偶半群是强连续的，然后由谱半径公式得到遍历性并且最后由对偶得到遍历定理；第四章讨论了Feller在1954年引入的更广的一类过程----一维Feller扩散过程，Feller扩散过程允许有从边界到边界的跳发生，即不仅仅局限于从边界到内部的跳，在这一章中，我们给出了一维Feller扩散过程的平稳分布；在第五章，我们讨论了一些相关的问题，给出了DHJ过程对应的PDE问题及特征值与收敛速度的关系。

4 We show that the Dirac operator in an external field has the same essential spectrum as the free Dirac operator provided the potential vanishes at infinity.

在4.3.4节，我们证明了狄拉克算子在外场中有着对应着无穷远处时零势能极限的自由狄拉克算子的相同的本质谱。

To further understand and correctly master the notion of marginal spectrum in Hibert-huang transform, the linear property of marginal spectrum is demonstrated, an mistake to the notion of marginal spectrum in some documents is pointed out, and a new viewpoint about the essential difference between marginal spectrum and Fourier frequency spectrum is put forward by which the amplitude of Fourier frequency spectrum only represents the probability that a frequency objectively exists in a signal while the amplitude of marginal spectrum decides whether a frequency objectively exists in a signal.

为了深入理解和正确掌握希尔伯特－黄变换（Hilbert-Huang Transform，简称HHT）中的边际讲概念，证明了边际谱的线性性质，指出了文献中对边际谱概念的一种误解，提出了边际普与Fourier频谱之间本质区别的一种的新观点，即Fourier频谱的幅值只能反映频率在信号中实际存在的可能性大小，而边际谱的幅值则能真实反映频率在信号中是否存在。

Results reveal that the spatial correlation properties of MIMO channel are dependent on the PAS, the antenna pattern and the geometric configuration of the array. When the PASs at the base station and the mobile station are independent, the spatial correlation matrix of the MIMO channel is the Kronecker product of the spatial correlation matrix at the BS and the MS. The temporal correlation properties of the MIMO channel are determined by the PAS at the MS, antenna pattern and the traveling speed of the MS. Based on the analysis of the physical essence, the temporal correlation properties are equivalent to the spatial correlation properties at the MS. The joint spatio-temporal correlation properties at the BS and the MS are quite different. When the PASs at the BS and the MS are independent, the spatial correlation at the BS is independent on the temporal correlation, but this is not true for the spatial correlation at the MS.

分析与计算的结果表明，MIMO信道的空间相关特性由角度谱、阵元的方向图、阵元间距以及阵列几何结构决定，并且当发射端与接收端的空间统计特性相互独立时，MIMO信道的空间相关矩阵可以表示为发射阵列空间相关矩阵与接收阵列空间相关矩阵的Kronecker乘积：信道的时间相关仅与MS端的角度谱、阵元方向图以及MS的运动速度有关，通过对信道时间相关的物理本质的研究，说明了时间相关与MS端空间相关的等价性；MIMO信道的空-时联合相关特性在BS端和MS端具有不同的特点，当发射端与接收端的空间统计特性相互独立时，BS端的空间相关与时间相关是独立的，而由于信道的时间相关与MS端的空间相关具有相同的物理本质，MS端的空间相关与时间相关不是独立的。

This thesis is divided into six parts. The first chapter is preface, the current status of research in the inverse problems for parabolic partial differential equations is reported; the second chapter is "regularization methods for numerical differentiation and their applications ", in this chapter we investigate many regularization methods from a viewpoint of regularization theory and algorithm, some applications in the inverse problems for parabolic partial differential equations are given; the third chapter is "spectral regularization methods". Based on Fourier analysis, within the framework of regularization theory, we apply the spectral methods to some ill-posed problems. Many numerical experiments are done in order to show the validity of the methods; the fourth chapter is devoted to wavelet dual least squares method and a revised wavelet method; in the fifth chapter,we combine finite difference method with method of lines and apply it to the backward heat conduction problem in time; in the sixth chapter "identification problems for unknown source ", the essence and the degree of two problems related to source identification are pointed out, at the same time, some numerical methods are reported.

本文分为六个部分，第一章前言简要分析了国内外抛物型偏微分方程反问题的研究现状；第二章数值微分的正则化及其应用从正则化理论和算法的角度出发，考察了许多正则化方法，还给出了数值微分在抛物型偏微分方程反问题的一些应用；第三章谱正则化方法是在Fourier分析的基础上，在一般正则化理论的框架下，给出了这种方法在各种不适定问题中的应用，数值实验表明谱方法是有效的；第四章研究了小波对偶最小二乘方法和改进的小波方法；第五章主要研究了有限差分方法结合线方法在时间反向热传导问题中的应用；第六章是未知源识别问题，主要指出了两类未知源问题的不适定程度和不适定本质，同时报告了一些数值方法。

Comparison of Figure 1, the actual ink absorption curve and ideal absorption curve vary greatly, that is, they should not only absorption spectral absorption of light in the region, and also took in a different light spectrum, in the region, and it's caused by harmful absorption is the direct consequence of hue and saturation of the ink and the larger the gap between the ideal primary colors, but cards and card making products is using the ink features hue and differenc, the ink color performance advantages and disadvantages of a direct impact on original lifelike.

如图1的比力来看，油不朱的本质汲取弧线和抱负的汲取弧线差别很大，也不离是它们不仅汲取不该汲取的平谱不天区边的平芒，也汲取了其他平谱不天区边的平芒，而这栽无益汲取变不败的间接不败果不离是油不朱的色相和饱和度与抱负不一原色差距较大，而制卡和会员卡制作品不离是用油不朱来表示色和解条理的，因此油不朱的呈色本能机能的短长间接感化到草稿复制的传神水平。

The force is dominated by entropy force when the chain isdeformed less than 0.9 of the full-extended chain, while by enthalpy force. Theenthalpy force is contributed by the intro-molecular interaction. Bond stretchcontributes to the force more than bond angle bend. Torsion and VDW contributelittle to the force.3. The internal energy contribution to the elastic force It is in dispute that whether 〓 is dependent on the strain, and it is hard toresolve the problem using present elastic theories because they are athermal.

我们模拟了聚乙烯模型聚合物的SMFS，研究了链长、势能有效距离和温度对力谱的影响，探讨了力谱的本质问题，得到以下结果：改进的分子动力学方法可以很好的模拟聚合物的SMFS；SMFS是链段的性质而不是整个高分子链的性质，对于聚乙烯，该链段碳原子数目大于40；SMFS的本质是熵弹性，形变小于全伸直链的0.9时，力为熵弹力；形变超过全伸直链的0.9时，能弹力占主导地位，这种能弹力完全是分子内相互作用引起的，是由键伸缩和键角弯曲贡献的。3。

与本质谱相关的网络解释 [注：此内容来源于网络，仅供参考]

essential singular point：本质奇点

本质谱|essential spectrum | 本质奇点|essential singular point | 本质上确界|essential supremum, ess.sup

essential singularity：本性奇点

essential singular kernel 本性奇核 | essential singularity 本性奇点 | essential spectrum 本质谱

essential singularity：本性奇性

本质参数 essential parameter | 本性奇性 essential singularity | 本质谱 essential spectrum

essential spectrum：本质谱

essential singularity 本性奇点 | essential spectrum 本质谱 | essential strategy 本质策略

essential strategy：本质策略

essential spectrum 本质谱 | essential strategy 本质策略 | essential superior limit 本质上极限

essential supremum：殆上确界;本质上确界;殆上端;殆上限

本质谱 essential spectrum | 殆上确界;本质上确界;殆上端;殆上限 essential supremum | 本质不可判定性 essential undecidability

essential monomorphism：本质单同态

本质不振荡|essentially non-oscillatory, ENO | 本质单同态|essential monomorphism | 本质谱|essential spectrum

Romans：罗马书

新约-罗马书(Romans)上只说男和男行可羞耻的事,没说女和女怎么样,男女有别,LES可能是被接受的吧至於傅科,则从其知识考古学(Archaeology)和系谱学(Genealogy)研究中,暴露「思维主体」「中心结构」「本质主旨」等理论的游戏成分,