查询词典 surface noise

The shockwave of the meteorite strike on the terrane of the surface passes the dynamic energy to the surface and forms the target terrane shatter cone; due to the fact that the terrane of stricken surface can not maintain the state of stress, a cluster of rarefaction wave was formed behind the shockwave to decompress terrane substances from high pressure state, this cluster of rarefaction wave ejects with high speed from the interface between the substances such as meteorite, surface terrane and lava, the shockwave compresses the target terrane substances, generating super-high temperature and forming a jet current of rock mass, rock powder, lava or rock fog with high pressure and temperature, the jet current lasted until the shockwave rebounded from the backside of rock, and the target of meteorite-stricken surface is formed on surface.

陨石撞击地面岩层时的冲击波把动能传给地表产生靶岩震裂锥，由于被撞击地表岩层不能维持应力状态，冲击波后面就发展一簇稀疏波使岩层物质从高压状态下减压，在陨石、地表岩层、熔岩等物质交界处高速喷出，冲击波压缩靶点岩层物质产生超高温，成为压力大温度高的岩块、岩粉、熔岩或岩雾喷射流，直到冲击波从岩石背侧反射、地面上形成陨击靶点。

It 's mainly used in steel tubes of high 's mainly used in steel tubes of high temperature superheaters with surface temperature temperature superheaters with surface temperature ≤625℃ and high ≤625℃ and high temperature reheaters with surface temperature temperature reheaters with surface temperature ≤650℃, and high ≤650℃, and high temperature headers and steam pipes with surface temperature temperature headers and steam pipes with surface temperature ≤600℃.

主要主要用于壁温≤625℃的高温过热器、壁温≤650℃的高温再热器钢管，以及壁温≤600℃的高温集箱温≤625℃的高温过热器、壁温≤650℃的高温再热器钢管，以及壁温≤600℃的高温集箱和蒸汽管道，国内外已逐步用该钢代替和蒸汽管道，国内外已逐步用该钢代替T22、F12、TP304L、TP347H等，但该钢焊接性能T22、F12、TP304L、TP347H等，但该钢焊接性能也比较差，容易产生焊接冷裂纹，所以同样要求有合适的预热温度和及时进行焊后回火处也比较差，容易产生焊接冷裂纹，所以同样要求有合适的预热温度和及时进行焊后回火处理。

By the FEA model that the recharge effect had been taken into account, the surface settlement and the surface differential settlement of the ground surface which was out of the recharge position could be greatly reduced, the recharge effect at far foundation pit wasmuch more apparent than at the near position. By the FEA model that the water-seal effect had been taken into account, the surface settlement and surface differential settlement of the ground surface could be largely reduced; the reduction of the total settlement and the differential settlement increased as the length of water-seal wall grew.

考虑回灌作用的有限元模型计算分析表明：设置回灌井或者回灌排水沟都可减小回灌处以外的地表总的沉降和不均匀沉降，随着排水沟离开基坑边距离的增加，回灌点以外的总沉降量和不均匀沉降都减少，回灌井埋设深度对周围地表沉降影响较小；通过考虑止水帷幕的有限元模型计算分析表明：设置止水帷幕可大大减小基坑周围土体总沉降和不均匀沉降，随着打设止水帷幕深度的增加，基坑周围地表总沉降和不均匀沉降都减小。

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。

Apply basic principle of control mechanical noise to measures had been put forward to reduce vibration and noise, and idle of the wood surface planer was remarkable reduced after the measures of reducible vibration and noise were used.

运用机械噪声控制的基本原理提出了减振降噪措施，试验证明，采用这些减振降噪措施后，木工平刨床的空转噪声有了显著下降。

In this article, the direction determining of low-noise targets and measurement of underwater noise level in the condition of surface noise is discussed.

文章摘要：文章对存在海洋表面噪声时的低噪声目标的方向测定问题和水下噪声级测定问题进行了讨论。

The noise radiation of the gear case is estimated by a special method, in which, the impact of the vibration phase of each partial surface and the time of the sound wave from the surface to the position at which the noise is calculated are taken into account.

考虑到噪声辐射面各部分的振动相位和声波从它们传播到计算噪声点的时间互有区别，使用了在复数域迭加声波的辐射噪声计算方法。用这种方法计算了齿轮箱的辐射噪声分布。与已有的理论和试验结果进行了对比。

The meaningful regions obtained by range image segmentation correspond to the surface patches of 3D object.The 3D surface patches are then reconstructed by the algebraic surface fitting method;the surface parameters are estimated by solving generalized eigenvector problem. The geometric model of 3D object is constructed from reconstructed surface patches by using CAD geometric modeling tool GEOMOD.

首先通过编码光栅方法获取三维物体的深度图象，并采用数学形态学的方法加以分割，然后利用代数曲面拟合手段对分割后的三维曲面片进行重建，并使用CAD几何建模工具由重建的曲面片构成物体的几何模型。

This paper on basis of surface's local principle.Through discussing the Gauss mipping image of the surface's asymptotic curve and the camber between any two directions of surface and the developable surface to illustrate the impact on surface of Gauss mipping.

文章以局部曲面的基本理论为基础，通过对曲面的渐近曲线、曲面上任意两方向的夹角和可展曲面的高斯映射象的讨论来说明高斯映射对曲面的影响。

In this paper four non-spherical surface types have been chose, ellipsoid surface, parabolic surface, pointed arch surface and conical surface. Base on the best fineness ratio, four surfaces are modeled, and their properties are analyzed in detail.

本文选择椭球面、抛物面、尖拱面、圆锥面这四种非球面面型整流罩，在基于整流罩最优的长径比的基础下，对各种情况分别进行建模，并对其光学性能进行了详细分析。

Salt is good, but if the salt becomes flat and tasteless, with what do you season it?

14：33 盐本是好的，盐若失了味，可用什么叫它再咸呢？

He reiterated that the PLA is an army of the people under the leadership of the Communist Party of China.

他重申，人民解放军是在中国共产党领导下的人民军队。