变均匀

For the purpose of extending the applicability of the coupling method to the bidimensional exterior steady Oseen problem, we will introduce a smooth artificial boundary separating an interior inhomogeneous region from an exterior homogeneous region .The solution in the exterior region is represented by an integral equation over the artificial boundary.

为了将这种耦合方法应用于二维外部定常的Oseen问题，我们人为的引入一条光滑的边界，将内部非均匀区域和外部均匀区域分离，外部区域的解可以由人工边界上的积分方程来描述，此积分方程同内部区域的速度-压力变分形式结合为耦合变分形式，我们则可以使用有限元的方法求解此耦合变分方程。

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。

Resul ts showed that material filling has inhomogeneity and time sequence, material r heological direction is mainly on longitude, and lateral rheology makes filling tend to homogeneousness.

结果表明，凸向模压成型时物料充填具有不均匀性和压缩时序性。物料流变以纵向为主，横向流变使充填趋于均匀。

The results indicate that the flow stress of the alloy increases with increasing strain rate and decreasing deformation temperature. The flow stress increases with increasing strain until the stress reaches the peak value, then the flow stress remains constant, which indicates that dynamic recrystallization happens during deformation. The flow behaviors are described by the hyperbolic sine constitutive equation, and the activation energy calculated is 337.75 kJ/mol. The as-forged microstructure consists of refined α2/γ and γ grains, and the grains are much homogeneous than before. The B2 phase distributes uniformly at the grain boundary of α2/γ and γ grains. The B2 phase decreases with increasing deformation temperature.

结果表明：流变应力随着应变速率提高和变形温度降低而增大；在变形过程中，流变应力随着变形量增大而增大，当流变应力达到峰值后趋于平稳，表明合金在变形过程中发生了动态再结晶；热变形过程的流变应力可采用双曲正弦本构关系来描述，平均激活能为337.75 kJ/mol；从合金的组织演化过程中可以看出，合金中不均匀的原始组织得到明显均匀化，变形后的组织是由α2/γ层片晶团和γ晶粒组成的双态组织，在α2/γ层片晶团和γ晶粒的晶界交界处发现分布均匀的B2相，并且随着变形温度升高B2相数量逐渐减少。

The deformation mechanism is mainly the single-slip and cross-ship, the fracture mechanism is mainly the congregation of transgranular micro-hole, and large uniform deformation occurred before tough fracture, and therefore, the ability of plastic deformation and the mechanical properties of the material were remarkably improved. These fully indicate that the new melt-treatment developed in this work is an effective and advanced technique, and further testify that the improvement of metallurgical quality of the material is the key to enhance its mechanical properties, especially its plastic deformation performance. The results of tensile and compression tests at elevated temperature also indicate that the suitable hot-working temperature range is 400～450℃. 4. A steady-state plastic flow exists during the plastic deformation of the aluminum sheet used for pressure can at elevated temperature. A hyperbolic sine relationship can be satisfied between the steady-state flow stress and strain rate by introducing an Arrhenius term which involves some thermal activation parameters, i.

压力罐用铝材中的主要冶金缺陷为Al〓O〓夹杂物、气孔及富Fe杂质相；高效熔体处理显著改善了材料的冶金缺陷的存在形态，使含杂量明显减少、夹杂物尺寸变细小且分布均匀，富Fe杂质相变为细小、分布均匀的团球状或短棒状的复杂化合物，同时也明显细化了结晶组织；此外，由于高效熔体处理有效地减少了材料中裂纹萌生源数量，因而改变了材料的塑性变形微观过程及断裂方式，主要以单滑移和交滑移进行塑性变形，断裂方式为穿晶微孔聚集型，韧性断裂前产生了大量的均匀变形，不易出现变形失稳，从而显著提高了罐用铝材的塑变能力和力学性能。

The analytical solutions for the ABCD matrices of uniform transmission lines are expanded into matrix infinite series with very simple terms, from which two important properties about the time-domain response of all kinds of transmission lines are obtained. The lines analyzed may have frequency-dependent parameters and arbitrary terminals.

由于网络理论中ABCD矩阵的特殊性质，该方法对非均匀传输线时域响应的分析具有更大的优越性，能分析的传输线可以具有频变参数和任意负载终端，给出了计算非均匀传输线ABCD矩阵的两种方法，一种是将非均匀传输线等效为一系列由长度很短的均匀传输线构成的子网络的级联，另一种是用单步法直接求解ABCD矩阵所满足的微分方程。

These systems include neutral particles with general spin and magnetic moment moving in an arbitrarily varying uniform magnetic field or in the field of a circularly polarized electromagnetic plane wave, the generalized time-dependent harmonic oscillator, and Heisenberg model in a rotating magnetic field.

包括具有一般自旋和磁矩的中性粒子在任意时变均匀磁场中的运动、在圆偏振平面电磁波场中的运动，一般含时谐振子体系，旋转磁场中的 Heisenberg 模型等。

Results CT showed a intrapelvic mass of rectal wall or surrounding soft tissue with inequality of size, relation closeness with intestinal wall; rectall wall different degree compression and narrowing,and extruding surrounding tissue.Below 5cm tumor density were slightly reduced,but symmetrical. Exceed 5cm tumor moderately enhanced, but asymmetrical. CT value of major mass were 25-35Hu, with boundary zone nodule enhancement, contrast-enhanced CT value 50-60Hu, and centricity necrosis.

结果 （1）盆腔内直肠壁或直肠周围软组织肿块，大小不等，肿块与直肠壁关系密切；（2）直肠不同程度的受压、变窄，肿块主要向直肠腔外生长，对周围组织产生推挤压迫；（3）径线在5cm以下肿瘤平扫时密度稍低，但均匀，增强时表现为中等度均匀强化，无坏死；径线在5cm以上10例肿块密度平扫时呈稍低密度且不均匀，CT值25-35Hu，增强时较大的肿瘤边缘带中等度结节样强化，CT值50-60Hu，肿块中心部分无强化，呈坏死样改变。

As the increasing of helix angle, the film thickness becomes more uniform.

结果表明，与水平光滑圆管相比，水平螺旋槽管表面的液膜变薄且分布变均匀。

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。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。