小膜

Neither was the material properties of cortical bone in tibia between the two groups at every stage of experiment.

卵巢切除对皮质骨的影响主要表现在使骨髓腔扩大，对骨外膜的影响较小，在短期内对皮质骨的力学性能无明显影响

Inflorescence a small cyme or glomerule, sometimes reduced to a solitary flower, leaf-opposed or terminal; bracts small, membranous.

花序一小聚伞花序或团伞花序，有时退化至一单生花的，叶对生或顶生；苞片小，膜。

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。

Fascial flap shift and planting back in natural position or dermatoplasty is an effective,simple and less surgical trauma method.

筋膜瓣转移+原位回植术是一种修复指骨外露指端缺损的简便、有效及创伤小的治疗方法。

The WPU we prepared has 20% solid content, about 80nm minimal particle diametre, pH value 7-8.5. It can be stored for 6 months under room temperature.

试验所制备的水性聚氨酯乳液固含量20%左右，pH7-8.5，最小粒径达到80 nm，室温乳液贮存稳定性大于6个月，涂膜断裂伸长率和拉伸强度等均达到或者超过皮革涂饰对水性聚氨酯的要求。

Periodic length and interface roughness of Mo/Si multilayers were determined by small angle X-ray diffraction.

Mo/Si多层膜的周期厚度和界面粗糙度由小角X射线衍射曲线拟和得到。

The structural and optical properties of the DLC films are analyzed by utilizing optical transmission, infrared absorption and small angle X-ray diffraction spectroscopy.

用光透射率、红外吸收谱和小角度X射线衍射谱分析了DLC膜的结构和光学性质。

Resulting the extraction technology of artificial culturing biofilms, the hydroxylamine hydrochloride (NH_2OHHCl) was selected to extract manganese oxides, and sodium dithionite (Na_2S_2O_4) was used to separate manganese oxides and iron oxides.

用选定的最佳条件对不同时间和地点采集的生物膜进行萃取，发现对目的组分的萃取率可达70.8%~94.6%，而对非目的组分的影响很小(3.3%~11.0%)，满足萃取分离的要求。

The reasons for these complications: The main arteries as a result of high blood pressure resulted in a series of changes, especially the long-term systemic small artery spasm, may cause the vessel wall occurred in dystrophic changes in subintimal deposition of protein substances, fibrous tissue increased , in the muscle membrane hypertrophy, reduced arterial elasticity, resulting in luminal narrowing.

产生这些并发症的原因：主要是由于高血压使动脉产生了一系列变化，尤其是全身小动脉的长期痉挛，可能使血管壁发生营养不良性变化，内膜下蛋白性物质沉积，纤维组织增多，中膜肌层肥厚，动脉弹性减低，以致管腔变窄。

The carbon based materials have low electron affinity even negative electron affinity,and have the good ability of eradiating electrons in electric field.

其中非晶碳膜具有好的化学稳定性和热稳定性、高的熔点和热导率、小的介电常数、大的载流子迁移率和高的击穿电压，是一种很有前途的场发射冷阴极材料。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。