轴膜

Results In 36 patients,CT was useful for the diagnosis of fracture,subarachnoid hemorrhage and multiple brain contusions,but missed 2 patients with brain contusion,5 patients with axis cylinders injury and 1 patient with subdural hematoma.MRI was more sensitive compared to CT with a miss of 3 patients with fractures,1 patient with axis cylinder injury and 4 patients with subarachnoid hemorrhage.

结果 36例中，CT对骨折、蛛网膜下腔出血及多发脑挫裂伤显示较好，但漏检2例脑挫裂伤、5例轴索损伤和1例硬膜下血肿；MRI病灶检出率较CT高，但MRI有3例骨折、1例轴索损伤和4例蛛网膜下腔出血不能检出。

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。

Ey membrane structure is 08 times larger than the strength of single storey one.

摘要］ 上海世博会世博轴膜结构屋面为世界上最大的膜结构工程。

Results: IVUS revealed that the cross-section views of coronary artery IMH appeared as a homogeneous, hyperechoic, crescent-shaped or circular area within media or between media or EEM, and the long axis views of IMH presented unbent or tortuous homogeneous space-occupying lesions with varied length.

结果：IVUS显示不冠状动脉壁内血肿的短轴观呈新月形或环形，呈等于或稍强于血液的斑点状回声，长轴观显示为中膜内或中膜与外膜之间长度不等的占位，形态或直或扭曲，呈接近血液回声或稍强回声。

Results: IL-8 protein was located in the epithelium of viii. The expression of IL-8 was significantly increased in RSA group than that in the control group. Positive IL-8 cells was shown in decidua of RSA group, and its IL-8 level was higher than that in the control group. By hematoxylin-eosin staining. trophoblastic layer was found to get thinner, cells of trophoblastic layer denatured or necrotized, and turned acidophily, and the fibration of villous axis increased in RSA; decidual cells lost connection, a part of decidual cells appeared cytoclasis and turned more acidophilic, and nuclei disappeared in RSA.

结果：在绒毛组织中，IL-8蛋白定位于绒毛上皮细胞的细胞质内，且病例组的表达明显高于对照组；在蜕膜组织中；病例组蜕膜细胞的胞质内可见IL-8蛋白表达，且高于对照组；H-E染色可见病例组绒毛组织的滋养层变薄，细胞变性甚至坏死、嗜酸性增强，绒毛中轴纤维化程度增强；蜕膜组织中蜕膜细胞失去细胞间连接，部分蜕膜细胞解体、核消失。

While the tissue spaces surrounding a few blood vessels wasAl and Fg positive,no Al or Fg positive cells were observed.In antemortem injurygroup,diffuse subarachnoid hemorrhage,cerebral edema,swelling or pyknotic neu-rons could be observed.The axons showed irregular swelling and disconnection at1～3h,marked swelling and disconnection at 6h,and retraction ball at 15h whichwas more remarkable at 24h after injury.The space between myelin sheaths andaxons was increased at 3～6h after injury.Tortuous and wavelike myelin sheathswhich adhered on axons incompletely,or even peeled off could be found from 15hto 24h after injury.Perinuclear lysis of Nissl bodies began at 24h after injury.Thenumber of GFAP positive cells in cerebrum and brain-stem increased significantlyfollowed by decrease,and then increased again,but the time courses of the changesin different areas of brain were not same.Al and Fg positive neural cells,mainlysurrounded blood vessels,with diffuse or peripherally distributed positive matter incytoplasm could be observed at 0.5h after injury.The number of Al or Fg positivecells and the intensity of immunoreaction increased with the time of injury.The areaof SYN positivity in medulla oblongata and pons decreased notably 3～6h afterinjury,then return to normal levels and continued to 24h after injury.

生前损伤组，可见广泛蛛网膜下腔出血，脑组织水肿，神经细胞肿胀，晚期神经元固缩；伤后1～3h见部分神经轴突不规则增粗、断裂，伤后6h断端膨大，伤后15h可见收缩球，至伤后24h更为明显；伤后3～6h可见部分神经髓鞘与轴突之间的间隙增宽，伤后15h髓鞘明显曲折，不完全附着在轴突两侧，甚至剥脱，持续到伤后24h；核周尼氏体减少在伤后24h才开始出现；同一部位的GFAP阳性细胞数目随损伤时间发生改变，先增多（最早在伤后0.5h），达到高峰后减少，其后又有增多趋势，但不同部位的GFAP阳性细胞数目增减的时间过程不尽相同，同时，大脑中的GFAP阳性细胞数目也有改变；伤后0.5h，可在脑干组织中见到Al和Fg阳性神经细胞，主要位于血管周围，阳性物在胞浆中呈弥散性分布，但部分细胞的阳性物仅分布于靠近胞膜的胞浆中而呈环状，随损伤时间延长，阳性细胞数目增多，反应强度增加；伤后3～6h，延髓及桥脑中的SYN阳性物面积减少，其后恢复到正常水平，并持续到伤后24h。

First, the angular velocity function and maneuver load for certain maneuver flight (including hover, dive-hike and these two combined) are set up. The simulation results of the vibration of double-disk rotor system with cantilever supported on rigid bearings show that rotor would be apparently deformed under maneuver load. Second, the performance of oil force of SFD in maneuver flight is analyzed. The results show that in maneuver flight, the SFD with centering spring will become eccentric and its oil force will be time-related and offset-related.

首先，建立了水平盘旋、俯冲拉起及盘旋+俯冲拉起复合机动三种机动飞行条件下的机动角速度函数，并确定了对应机动飞行条件下的机动附加载荷（附加离心力和附加陀螺力矩），分析了带刚支的双盘悬臂转子系统在机动飞行条件下的振动特性，发现发动机转子在机动飞行时会发生明显变形；随后，分析了非定心挤压油膜阻尼器的油膜力特性，机动飞行时，油膜轴颈在机动附加载荷的作用下偏离外环中心，使得带定心弹支的挤压油膜阻尼器也变成了非定心挤压油膜阻尼器，其非定心挤压油膜力是瞬态时变的，并且与SFD油膜轴颈偏移量和进动形态有关；然后，在经典的Jeffcott转子系统中引入带定心弹支的挤压油膜阻尼器，分析了机动飞行时非线性转子系统的振动特性，发现挤压油膜阻尼器油膜力的非协调特性也反映到转子系统的振动响应中；之后，对机动飞行条件下带挤压油膜阻尼器的双盘悬臂转子系统的振动特性进行了分析，并重点分析、总结了俯冲拉起机动飞行时，系统结构参数和工作状态参数（转速比、机动飞行半径、机动角速度等）对该系统振动特性的影响。

First, the angular velocity function and maneuver load for certain maneuver flight (including hover, dive-hike and these two combined) are set up. The simulation results of the vibration of double-disk rotor system with cantilever supported on rigid bearings show that rotor would be apparently deformed under maneuver load. Second, the performance of oil force of SFD in maneuver flight is analyzed. The results show that in maneuver flight, the SFD with centering spring will become eccentric and its oil force will be time-related and offset-related. Then, SFDs are introduced into typical Jeffcott rotor system. The whole system will be statically displaced in maneuver flight and the nonsynchronous components of oil force appear in the response of rotor system.

首先，建立了水平盘旋、俯冲拉起及盘旋+俯冲拉起复合机动三种机动飞行条件下的机动角速度函数，并确定了对应机动飞行条件下的机动附加载荷(附加离心力和附加陀螺力矩)，分析了带刚支的双盘悬臂转子系统在机动飞行条件下的振动特性，发现发动机转子在机动飞行时会发生明显变形；随后，分析了非定心挤压油膜阻尼器的油膜力特性，机动飞行时，油膜轴颈在机动附加载荷的作用下偏离外环中心，使得带定心弹支的挤压油膜阻尼器也变成了非定心挤压油膜阻尼器，其非定心挤压油膜力是瞬态时变的，并且与SFD油膜轴颈偏移量和进动形态有关；然后，在经典的Jeffcott转子系统中引入带定心弹支的挤压油膜阻尼器，分析了机动飞行时非线性转子系统的振动特性，发现挤压油膜阻尼器油膜力的非协调特性也反映到转子系统的振动响应中；之后，对机动飞行条件下带挤压油膜阻尼器的双盘悬臂转子系统的振动特性进行了分析，并重点分析、总结了俯冲拉起机动飞行时，系统结构参数和工作状态参数(转速比、机动飞行半径、机动角速度等)对该系统振动特性的影响。

Combining with the characteristics of membrane surface fulcrum system of Expo Axis, the main installation technologies are put forward, including installing external and middle masts synchronously fixed by temporary wind cable, installing horizontal cable firstly and backstays at last during construction.

结合世博轴膜面支点系统的特点，指出其主要安装技术路线，即外桅杆、中桅杆同步安装，临时缆风索固定，施工区间先安装水平索最后安装背索。

When the flexible shaft~bearing system was excited with the second order frequency, the maximum oil pre

在二阶频率的正弦载荷作用下，弹性轴-轴承系统的最大油膜压力远大于刚性轴-轴承系统，而其最小油膜厚度则远小于刚性轴-轴承系统。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。