查询词典 papoose root

The static natural frequencies and dynamic frequencies (under 3000rpm) are calculated by the finite element method and cyclic symmetry technique. The rotating vibration behaviors of the two models are compared. Different vibration characteristics between the two models are discussed. Geometry mismatch in a turbine blade root, which arose in manufacturing process or caused by wearing out during service, leads to contact conditions changed in fir-tree attachments. As a result, shifting of the fundamental frequencies and redistribution of stress in the blade base possibly cause failure of the blade.

在叶片—轮盘耦合系统振动研究方面，建立了带围带的叶片振动计算模型和带围带的叶片—轮盘耦合系统振动计算模型，考虑旋转离心力作用，采用波传播技术，对两种模型分别进行了整圈模态分析，得到了某汽轮机叶片模型和叶片—轮盘耦合模型在0转速和工作转速(3000rpm)下的振动模态，并对所得结果进行分析比较，讨论了整圈叶片振动模态与叶片—轮盘耦合振动模态的区别。

In short, the problem is cyclical, rather than the root cause of problems.

总之，问题是周期性的，而不是问题的根源。

Root fusiform or cylindric, 3–10 × 0.3–0.8 cm.

根纺锤形的或圆筒状， 3-10 * 0.3-0.8 厘米。

Aerating roots (or knee root or knee or pneumatophores or Cypress knee ): roots rising above the ground, especially above water such as in some mangrove genera.

曝气根（root 或膝盖或膝盖或呼吸根或赛普里斯尼）：根以上的地下水上升，特别是在一些如上述红树属。

The mitosis coefficients were decreased,in an other word, AlCl_3 has marked cytogenesis toxic effect on the root tip cells of Garlic.

用不同浓度的三氯化铝分别处理大蒜根尖6h，18h，24h，结果表明：各处理组均对大蒜根尖细胞有丝分裂产生抑制。

A great dam has been built up so as to eliminate the root of flood, which used to endanger the people along the river.

一座大坝已经建立起来，从而彻底根除了过去威胁着沿岸人民安全的洪水。

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。

Rhizoctonia cerealis was the most inhibited (89.3%) among the 11 species. A dry seed treatment of α-pyrone 0.2% WP at 0.5% controlled wheat root rot 61.6% and cotton damping-off 85.6% in the greenhouse; these re...

温室条件下用干种子量0.5%的0.2%α-吡喃酮WP拌种处理对小麦纹枯病的防治效果达61.6%，对棉花立枯病的防治效果达85.6%，较干种子量1%的40%多菌灵拌种处理防治效果分别提高了14.6%和17.9%。

But he said,'No, lest perhaps while you gather up the darnel weeds, you root up the wheat with them.

13：28 主人说，不必，恐怕薅稗子，连麦子也拔出来。

This isn't something that we can just dash off – we're going to have to get to the root of the problem.

我们不能就这样草草了事，一定要找出问题的根源。

The Porsche Owner: But it's my car!

可，这是我的车呀。

LOX_83}{Oh, another bunch of wackos.

{LOX_83}{呃，又一群怪人。