查询词典 radial acceleration

Contributions of the centripetal acceleration in steady flight, the tangential acceleration due to the effect of the angular acceleration, the Coriolis component of acceleration, the radial (the vertical direction at prototype), circumferential and axial (the two horizontal directions at prototype) shaking effects and the elongation effect of the centrifuge arm to the global acceleration of a particle in centrifuge modelling are identified in the expression of the global acceleration.

笔者描述了整体加速度表达式中各项的物理意义，指出了离心机稳定运转时的向心加速度、由角加速度效应引起的切向加速度、互补加速度分量、径向、环向和轴向振动效应以及离心机臂伸长效应对整体加速度的贡献。

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。

Direction of the human radial artery by the cubital fossa at the midpoint of the bottom of 2.5CM connection to the radial styloid process is not a vertical direction of blood vessels, a large number of data measurement, based on the basis of the treatment instrument designed to meet the ergonomic parameters of the radial artery into the actual trajectory of the laser positioning warehouse ladder-type arrangement, thus ensuring the laser projection domain and the radial artery into a high degree of matching of the laser spot can be an accurate projection exposure to the region in the radial artery through the line to avoid exposure is invalid.

人体桡动脉的走向是由肘窝中点下方2.5CM处至桡骨茎突的连线，并非是一条垂直走向的血管，在大量数据测量的基础上，本治疗仪依据人体工程学参数设计了符合桡动脉血管实际走向轨迹的激光定位仓阶梯型排列，从而保证了激光器投影域与桡动脉走向的高吻合度，使激光投影的光斑能准确照射在桡动脉循行区域，避免无效照射。

The results were as follows the airdried density ( moisture content of wood is 12%), the basic density and the ovendry density were 0.583 g·cm-3, 0.462 g·cm-3 and 0.507 g·cm-3 respectively, the airdried density was at the medium level in domestic wood species;the shrinkage coefficient of radial, tangential and volumetric were 0.099%, 0.183% and 0.296% respectively, the maximum swelling were 4.106%, 7.958% and 12.627% respectively;the ratio of tangential shrinkages to radial shrinkages was 1.5-1.9;the toughness was 52.12 kJ·m-2;the hardness of cross, radial and tangential section were 41.53 MPa, 31.41 MPa and 35.51 MPa respectively;the compressive strength parallel to grain was 44.50 MPa ;the modulus of elasticity in static bending and the bending strength were 12.63GPa and 127.31 MPa respectively;the shearing strength parallel to grain of radial and tangential were 8.76 MPa and 10.54 MPa respectively;the cleavage strength to grain of radial and tangential were 124.3 N·mm-1 and 138.6 N·mm-1 respectively.

结果表明大叶栎木材的气干密度（含水率为12％）、基本密度和全干密度分别为0.583 g·cm-3、0.462 g·cm-3和0.507 g·cm-3，气干密度属于国产木材的中等级水平；径向、弦向和体积干缩系数分别为0.099%、0.183%、0.296%，湿胀率依次为4.106%、7.958%和12.627%，差异干缩为1.5-1.9，其尺寸稳定性较好；冲击韧性为52.12 kJ·m-2，端面、径面和弦面硬度分别为41.53 MPa、31.41 MPa和35.51 MPa，顺纹抗压强度为44.50 MPa，抗弯弹性模量和抗弯强度分别为12.63 GPa和127.31 MPa，径面和弦面顺纹抗剪强度分别为8.76 MPa和10.54 MPa，抗劈强度依次为124.3 N·mm-1和138.6 N·mm-1。

In the process of practical operation of radial gates, the vibration of radial gates often occurs in the following situations: when radial gate is being opened or closed or part-opened, and sometimes even under the completely closed condition. Under some situations, the vibration of radial gate is so serious that the dynamic failures of radial gates or dynamic instability of some gate components may happen.

弧形闸门的运行实践表明，闸门在启闭过程或局部开启时，甚至在关闭挡水时，常常产生振动，振动有时会达到相当严重的情况，从而可能引起闸门的动力破坏或某些构件的动力失稳。

The acceleration profile of the crane motion is designed to induce minimum payload pendulation during transpo rt,while the deceleration stage is designed to ensure freed om of residual oscillation near the end of the transport,and to deliver the payload at the target point.The techniques induce payload pendulation at least one half ofan oscillation cycle or integer multiples during each of the acceleration and deceleration stages.Starr(1995)designed a symmetric two-step acceleration and deceleration profile to transfer a suspended object.The duration on the constant acceleration steps is assumed to be negligible relative to the period of the payload oscillation.A linear approximation method of the oscillation period is used to generate the two-step symmetric acceleration profile.

3.1投入成型技术，各种形式的投入shapers ， convolved参考命令，产生形投入指挥，驾驶起重机提出一套距离沿一套path.the加速度概况起重机议案旨在诱使最低载重pendulation期间transpo rt ，虽然减速阶段，目的是确保freed om残余振荡接近尾声的运输，并交付载荷到达目标point.the技巧诱使载荷pendulation至少一半ofan振荡周期或整数倍数。

A hemadynamometer has an air bag designed for attaining oppression or ischemia of radial artery only without oppressing ulnar artery, with a length of the bag made, when the bag is wound on a user's wrist on its radial side starting from such hard organization area as tendons on palm side of the wrist through the radial artery, to reach at least styloid process of radius but not to reach the ulnar artery, and with a width set for locally oppressing the radial artery at least substantially right above the styloid process of radius in longitudinal direction of the wrist.

一种用来仅对桡骨动脉进行压迫并使其局部缺血而不对尺骨动脉进行压迫的血压测量计，它具有一气囊，气囊具有一定长度，当将气囊裹绕在使用者手腕上，使气囊从如手掌侧上的各腱这种坚实组织区域开始作为起点，伸展经过桡骨动脉时，所述气囊可以至少到达桡骨茎突，但不能到达尺骨动脉，所述气囊具有一宽度，该宽度设定得可以至少在沿手腕纵向、在桡骨茎突的基本正上方的位置处、对桡骨动脉进行局部地压迫。

objective to assess the effects to utilize minitype plate internal fixation in radial head fracture of mason ⅲ.methods 10 cases of patients with closed radial head fracture under went minitype plate internal fixation by open reduction,and the functional evaluation of elbow was carried out by the pain,stability,myodynamia of elbow,together with the elbow joint score of broberg and morrey.results in 10 case of patients with 12～24 months follow up(average time 20 months),the elbow joint mean score is 58(30～90) with excellent case 1,good 4,poor 5,and the fineness rate is 50％.conclusion it is failed to treat complicated radial head fracture by minitype plate internal fixation,while maybe it is better to resect or replace radial head for these types.

目的 评价微型钢板治疗masonⅲ型桡骨小头骨折的临床效果。方法对10 例masonⅲ型骨折进行微型钢板内固定，根据患者肘关节活动疼痛、稳定性和肌力情况，依照broberg和morrey肘关节评分标准进行功能评价。结果 10 例患者随访12～24个月，平均20个月，肘关节平均评分58 分(30～90)分，其中优1 例，良4 例，差5 例，优良率50％。结论切开复位微型钢板内固定治疗复杂的masonⅲ型桡骨小头骨折，不能取得良好的临床效果，如果要获得较好的肘关节活动和早期康复，可考虑桡骨小头切除或置换。

Daubechies'wavelet frame theorem is extended from one dimension to n dimensions. According to this framework, an example of n-dimensional radial wavelet is given. Differing from tensor product multidimensional wavelet, the radial wavelet is inseparable, locally supported and infinitely differentiable. The family, obtained by dilations and translations from this radial wavelet, constitutes a special type of radial wavelet frame in L〓.

Daubechies的框架定理推广到了n维情形，同时，也按照这一理论框架，给出了高维二进径向小波的具体例子，具有下列性质：ψ是无穷次连续可微的；ψ是局部支撑的，支集为‖x‖≤1；ψ含有分式因子，因此对&奇异点&更为敏感；ψ是不可分的，不同于张量积形式的高维小波；ψ是各向同性的。

A great upsurge has been growing up in technique research of preventing against accidents in running automobiles We propose a scheme of using tire-mounted MEMS accelerometer to sense tire radial acceleration, the radial acceleration signals in braking period are sent to outer receiving system and used as a basis of braking performance monitoring indirectly.

采用汽车轮胎内置传感器的事故防范技术正在兴起。文中通过轮胎内置MEMS电容加速度传感器来获取径向加速度，把制动时段的径向加速度信号向外传送，用作间接监测汽车制动性能的依据。

Hanna: That's over now, isn't it?

都结束了，对吗

You must be ill. You look so pale.

你一定是病了，你的脸色苍白。