查询词典 increasing directed set

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。

To resolve directed cutset of Directed Assembly Connection Graph, an efficient algorithm for the enumeration of all directed cutsets of DACG was presented. This algorithm recursively enumerated a part of DACG directed segs which had one connected subgraph by using the theory of edge contraction.

为解决有向装配图有向割集的求解，给出一个生成有向装配连接图有向割集的高效算法，该算法优先考虑检查有向割集两个子图间边的方向。

The results of cold-flow model test indicate:(1) the pressure drop rises with increasing air quantity and solids quantity respectively, however, much more air quantity and solids quantity minish in the same height position;(2) the pressure drop rises with increasing solids quantity;(3) the average granule concentration minishes with increasing air quantity, and rises with increasing the granule quantity in the same level position;(4) the inhomogeneity of distribution granule concentration minishes with increasing air quantity, and rises with increasing the granule quantity in the same level position.

结果表明：(1)在同一高度截面上，循环流化床反应器炉膛内压降随风量的增加而增加，但是风量过于增大反而使压降在同一截面上减小；(2)压降随初始物料量的增加而增加；(3)在同一水平截面上，颗粒浓度随风量的增大而逐渐减小，随物料量的增大而增大；(4)颗粒浓度分布的不均匀性随风量的增大逐渐减小，随物料量的增加不断增大。

For an abitrary set X, appropriate order relations on WCL (the set of all weak closure operators), WIN (the set of all weak interior operators), WOU (the set of all weak exterior operators), WB (the set of all weak boundary operators), WD (the set of all weak derived operators), WD*(the set of all weak difference derived operators), WR (the set of all weak remote neighborhood system operators) and WN (the set of all weak neighborhood system operators) can be defined respectively, which make WCL, WIN, WOU, WB, WD, WD*, WR and WN to be complete lattices that are ismorphic to CS(X,CS is the set of all closure systems on X.

证明了可以在WCL(X上的弱闭包算子的全体)、 WIN(X上的弱内部算子的全体)、 WOU (X上的弱外部算子的全体)、 WB (X上的弱边界算子的全体)、WD、 WD*(X上的弱差导算子的全体)、 WR(X上的弱远域系算子的全体)和WN(X上的弱邻域系算子的全体)上定义适当的序关系，使它们成为与CS(X，〖JX-*5[JX*5]同构的完备格其中CS(X是给定集合X上的闭包系统的全体。

Given a ring and a set of communication requests. Each request is represented by a pair of nodes, and associated with a profit. To satisfy a request in the undirected ring, we need to determine a path between the two nodes of the request in the ring. To satisfy a request in the directed ring, we need to determine a directed path from the source to the destination of the request in the directed ring. The goal of the call admission control problem is to determine and satisfy a maximum profit subset of the requests such that for every edge of the ring, the number of satisfied requests that are routed through the edge does not exceed the capacity of the edge.

要在无向环中实现一个呼叫，需在环中指定该请求所对应的两个顶点之间的一条路，要在有向环中实现一个呼叫，需在环中指定该请求的源节点到目的节点的一条路，环网络呼叫接纳控制问题的目标是确定最大利润的呼叫子集，在环中实现该子集中的每一个呼叫，使得经过每一边的呼叫的数目不超过该边的容量，对于无向和有向环网络呼叫接纳控制问题，我们均首次给出了多项式时间近似方案。

Layout segmentationand block recognition is combined in this algorithm which improves the processingefficiency.4 determination of logical order in layout based on directed graph.Space structure directed graph is set up from analysis the space structure of layoutobjects. This transfers the determination of logical order of layout objects into traversingsearch in directed graphs, from which the logical order of layout object is determined.

可以看出，该算法将版面分割与区域识别相结合，提高了算法的效率。4、基于有向图的版面对象顺序确定该算法利用版面对象的空间结构建立空间结构有向图，将版面对象之间的顺序确定，转换为在有向图空间进行遍历搜索的过程，通过图的遍历生成遍历树来确定版面对象顺序。

In the case of granite, observation results indicate that the extending routes of active cracks are mainly intercrystalline, transcrystalline, inter-transcrystalline, and intracrystalline. When the strain rate is low, the long intercrystalline cracks are prevailing, and with increasing of the strain rate, the short transcrystalline and intracrystalline cracks gradually increase. The statistic results show that the active crack density increases with increasing of the strain rate, and the mean length of active cracks diminishes with increasing of the strain rate, that is, the induced damage in comminuted product increases with increasing of the strain rate. For the first time this dissertation integrates macroscopic results of comminution with active crack growth under impact loading. It elucidates why the dynamic comminution strength of mineral beds increases with increasing of the strain rate through the active crack extending, and analyzes the influence of structure and constitution of minerals on their damage under impact stress. It is authenticated that both the size distribution and the damage population of comminuted product can be characterized by the fractal.

为分析料层颗粒在冲击下的细观损伤效果，采用德国生产的ASM68K半自动图象分析仪对粉碎生成物中的损伤情形进行了观测，以花岗岩为例，观测结果表明花岗岩颗粒在冲击应力下的活化裂纹扩展路径主要表现为沿晶、穿晶、沿穿晶和晶内等形式，在低应变速率下，活化裂纹以沿晶裂纹较多，随着应变速率的提高，其它裂纹形式大量繁衍，统计结果表明活化裂纹密度随着应变速率的增大而增大，活化裂纹的平均长度随着应变速率的增大而减小，综合表现为颗粒的细观损伤程度随着应变速率的增大而增大；首次将应力作用下的活化裂纹演化特征与粉碎的宏观效果相联系，并就料层动态粉碎强度随应变速率增大而提高的现象从裂纹演化特征的角度进行了解释；分析了矿岩构造结构特性对损伤产生和分布的影响。

And also the device was simulating. The results of cold - flow model test indicate that pressure drop rises with increasing air quantity and solids quantity respectively, however, much more air quantity will make pressure drop minish in the same height position;The average concentration of granule minishes with increasing air quantity, and rises with increasing solids quantity in the same height position;The inhomogeneity of distribution of the average granule concentration minishes with increasing air quantity, and rises with increasing the granule quantity.

冷态实验结果表明：流化床内同一高度截面与基准面之间的压差是随风量的增加而增加的，但是风量过于增大反而使同一高度截面与基准面之间的压差减小了，同时，压差是随初始物料量的增加而逐渐增加的；在同一高度截面上，颗粒平均浓度随风量的增大而逐渐减小的，随物料量的逐渐增大而增大的；颗粒浓度分布的不均匀性随风量的增大而逐渐减小，而随物料量的增加而不断增大的。

Single factor experiments were done with the factors including the width of protrusion and the trolley's velocity, which showed that the surface frictional coefficient decreases with the width of protrusion increasing, and doesn't change with the trolley's velocity changing, which was consistent with the results of the orthogonal experiment. A theoretical model of the horizontal projection of a corrugated bionic surface's contact area was built, which showed that the contact area's horizontal projection decreases with width and interval increasing respectively and that the ratio of the contact area's horizontal projection and the vertical load decreases with the vertical load increasing. It indicated that the surface frictional coefficient decreases with the above three factors increasing respectively. Finite element modeling and analysis of interactions of a plate and soils was done using ANSYS, which showed that the plate frictional coefficient is little relative to soil elastic modulus and decreases with vertical surface pressure and that trolley's pull and vertical displacement of bionic surface's control pilot keep constant almost during the plate being pulled. Finite element modeling and analysis of interactions of a corrugated bionic surface and soils was done using ANSYS, which showed that surface frictional coefficient is little relative to soil elastic modulus and decreases with bionic surface's structural parameters and vertical pressure increasing. However, the three factors all didn't affect the surface frictional coefficient remarkably on the condition of 90% dependability. For the first time, bionic surfaces were applied to screw piles, which formed bionic screw piles, and the contrast experiments showed the bionic screw pile had certain resistance-decreasing effects.

建立了波纹型仿生曲面与土壤的接触面积的水平投影的理论模型，表明接触面积的水平投影A随着波纹型仿生曲面突起宽度、两相邻突起间距的增大而减小，接触面积的水平投影与波纹型仿生曲面表面垂直载荷之比随着波纹型仿生曲面表面垂直载荷的增大而减小，进而得出仿生曲面摩擦系数随着波纹型仿生曲面突起宽度、两相邻突起间距以及表面垂直载荷的增大而减小；利用ANSYS软件对平板与土壤的相互作用进行了有限元建模与分析，表明平板摩擦系数与土壤弹性模量关系不大，而随着表面垂直载荷的增大而减小；平板牵引过程中台车牵引力和仿生曲面控制节点垂直方向位移基本保持不变；利用ANSYS软件对波纹型仿生曲面与土壤的相互作用进行了有限元建模与分析，表明波纹型仿生曲面系数在一定范围内基本不受土壤弹性模量的影响，随着波纹型仿生曲面突起宽度、两相邻突起间距以及表面垂直载荷的增大而减小，但在可信度为90％的前提下，三个因素影响都不显著；首次将波纹型仿生曲面应用于与土壤作用方式以挤压为主的螺旋桩，形成仿生螺旋桩，并与普通螺旋桩进行了沉桩对比试验，表明波纹型仿生曲面应用于螺旋桩桩体表面具有明显的降阻作用。

Other starring roles include her portrayal of the actress of dubious talent, Delores Fuller in Touchstone's "Ed Wood," directed by Tim Burton and co-starring Johnny Depp; Disney's "Hocus Pocus," directed by Kenny Ortega with Bette Midler and Kathy Najimy; and Columbia Pictures "Striking Distance," directed by Rowdy Herrington, opposite Bruce Willis.

当你和法国人谈判时，即使他们英语讲得很好，他们可能也会要求用法语进行谈判。在这点上，他们很少让步。这似乎标志着法国人与美国人有着"不共戴天"之仇，甚至在加拿大的法语区魁北克，政府掏钱让他们设立英语标牌，他们也坚决拒绝。

Diabetes is a social disease that affects several million people worldwide.

糖尿病是一个社会性疾病，全世界有数百万人罹患此病。

I'll call you on Friday to see if we can reschedule our luncheon meeting at your convenience.

我星期五会给您打电话在您方便的时候我们重新安排我们的午餐约会。