查询词典 time of vibration

Based on a series of signal process and noise source identification techniques, especially the major noise source identification methods, such as expurgation method, sound intensity analysis, spectrum analysis vibro-acoustic correlation analysis and so on, the pass-by noise control of SC7080A and SC6360B are studied in detail. By the roadway and dais experiments, the major noise and radiating parts are identified and some economical controlling methods are made. For the SC7080A, to control the emissing noise from the intake and shell vibration of air cleaner, a intake muffler is installed between the air cleaner and intake valve. Based on the theory of Helmholtz resonator, One three-parallel-connected resonant silencer is designed and trial-manufactured. For the SC6360B, the attenuation performance of exhaust muffler in high frequency region is improved. To reduce the vibration noise of shell part, the structure of oil sump tank, exhaust manifold shield and exhaust manifold shield are analyzed and improved. At the same time, some measures, such as sound absorption, sound insulation, are taken to reduce the noise of engine surface emissivity and a sound shield is designed.

本文首先综述了目前国内外汽车加速噪声控制的现状、主要方法和技术措施，在此基础上，结合SC7080A和SC6350B汽车的车外加速噪声水平及现状，综合运用分别运行法、声强法、频谱分析法、声振相干函数法等现代噪声源识别方法，对SC7080A和SC6360B汽车进行了准确详细的车外加速噪声源识别并提出了经济可行的控制方案，针对SC7080A，主要在空气滤清器和进气阀门之间的进气管道上加装进气消声器，抑制空气滤清器壳体表面和进气口两处的噪声辐射，根据Helmholtz共振腔原理设计了三腔并联旁支型共振消声器，并进行了工程化设计和试制；针对SC6360B，主要改善了排气消声器在高频段的消声性能，对罩壳类零件进行了结构改进，降低了其表面噪声的辐射，并对发动机舱进行了吸声、隔声处理，设计了发动机隔声罩。

The time-frequency analysis of nonstable torsional vibration signal and multiresolution analysis based on wavelets of torsional vibration signal are introduced in chapter 5 and chapter 6 respectively.

第六章着重讨论了小波分析在扭转振动信号的频带分离和噪声滤除中的应用。

So we designed a adaptive synchronizing controller based on hereinbefore hardware environment: first a small magnitude reference signal r is outputted to system through the signal card (to ensure that the vibrating system works in a linear state), and this signal is sent to the moving coil of vibrator through the power amplifier, so vibration is produced through electromagnetic induction. Secondly the vibration signal can feedback to the data acquiring card in the servo system through the acceleration sensor on the Vibroseis reactor M〓 and the base-plate M〓, then the computer can get the current vibrating state y〓 of the coil of vibrator according to the feedback information from the data acquiring card, and give a real time comparing between the current state y〓 and the reference output y〓 of the set-in reference model with current reference input being r , then regulates the correlative controlling parameters according to the error e〓=y〓-y〓 till y〓→y〓, finally normal signal sweeping begins with a certain phase fixed. Meanwhile a synchronization signal for seismic signal record is sent to seismograph from synchronization signal outputting component in the Vibroseis system to perform the controlling process of synchronization of sweeping phases.

为此，我们基于以上的硬件环境设计了一个自适应同步控制器：首先通过信号发生卡对系统输出小幅度的参考信号r(从而保证振动系统工作处于线性状态)，信号通过前置放大器、功率放大器等送到激震器动圈，并通过电磁感应产生振动，振动信号通过可控震源激震器反应块M〓和基板M〓上的加速度传感器反馈给伺服系统中的数据采集卡，工控计算机根据采集卡的反馈信息，获取当前激震器动圈的振动状态y〓，并实时地将该状态与内置的参考模型在当前参考输入r下的参考输出y〓进行辨识，再将两者输出误差e〓＝y〓-y〓对系统的有关控制参数进行调整，直至y〓→y〓，最后在经过某一固定的相位后，开始信号的正常扫描过程，与此同时，由可控震源系统的同步信号输出部件向地震仪送出一地震信号记录同步信号，进而完成扫描相位同步控制过程。

Secondly, the cutter of the machine was studied from reducing vibration, emphasis on knives array, homeostasis. To apply "ANSYS"method, At the same time, it was known that inherent frequency of the main axis was so far higher than vibratory frequency, and the machine main axis'rotational speed won't cause sympathetic vibration.

其次，本文从减少振动入手对9LRZ-80型秸秆揉切机的关键部件切碎器进行分析，着重对动刀片的排列、动平衡等进行分析研究，并通过有限元分析，得到切碎器主轴固有频率远远大于机器振动频率，机具的转速不会造成共振的危害。

By using the transfer matrix method of multibody system, the hard problem of computation of the vibration characteristics of LRMLRS coupled with rigid bodies and elastic bodies is solved which is very difficult to the ordinary dynamic methods, and the vibration characteristics of LRMLRS which is varied when the number of rockets in the launch device is varied, is obtained conveniently. By developing augmented eigenvectors of the LRMLRS and its orthogonality conditions, the nonorthogonality problem of the multibody system including rigid bodies and elastic bodies is solved and the exact analysis of the dynamics response of the LRMLRS including rigid bodies and elastic bodies is realized. By using the random integer programming method, the hard optimization problem which contains continuous variables, discrete variables and random variables at the same time is solved. This method provides a technology for optimum design with random variables and discrete variables. The dynamic optimum design is realized to decrease the number of rockets consumption in the LRMLRS test. The simulation system of dispersion of fire is established by using the maximum entropy method to estimate dispersion of fire.

通过应用多体系统传递矩阵法，解决了刚弹耦合远程多管火箭多体系统振动特性这一通常力学方法不便于解决的计算难题，方便地获得了远程多管火箭振动特性及其随发射架上火箭弹个数变化而变化的情况；通过构造增广特征矢量及其正交性条件，解决了刚弹耦合多体系统特征矢量不具有通常意义下的正交性的难题，实现了对刚弹耦合远程多管火箭动力响应的精确分析；应用随机整数规划法，解决了同时考虑连续、离散和随机变量等多种设计变量的优化设计难题，为含随机和离散变量的优化设计提供了手段，实现了减少远程多管火箭试验用弹量的动态优化设计；建立了应用最大熵法估计的密集度仿真系统，优化射序和射击间隔，实现了提高远程多管火箭射击密集度的动态优化。

Firstly, achieving a new low and high cycle noninterfering loading, the high frequency induction local heating, the control of high cycle vibration frequency and amplitude, and the crack propagation real-time detection, an experimental system of L-HCCF at elevated temperature is established. Secondly, under two vibration frequency (50Hz and 100Hz), the contrast experiment of light and serious corrosion disc slots is done. It is found that the experimental L-HCCF life of serious corrosion disc is less than that of light's, but its dispersion is larger, and the experimental failure is identical with the service's.

首先，进行大量试验工作，提出了高低周疲劳载荷的新型加载方案，并解决了高频感应局部加温、振动调频及裂纹实时监测等多个技术难点，建立了涡轮盘全尺寸高温复合疲劳试验系统；验证试验做到了故障再现；接着进行了两种频比（振频50HZ与100HZ）的轻、重腐蚀盘的对比试验；由对榫槽第一齿进行裂纹实时跟踪，得出了枞树型榫槽的复合疲劳裂纹扩展特点规律；对榫齿断口进行的金相分析表明：裂纹首先由第一齿开始，断口系复合疲劳；试验结果显示：重腐蚀盘试验寿命较轻腐蚀盘有显著的下降，而且分散性较大。

The bifurcation and chaos behavior of impact and rubbing fault rotor system caused by the parameters of nonlinear rigidity, rotor rotating speed, eccentric mass is analyzed, in the numerical value analysis method. The bifurcation diagrams, maximum Lyapunov exponent diagrams, Poincaré maps, phase plane portraits, trajectories of journal center, time-history curve, amplitude spectra diagrams of the rotor motion are used. The convert and evolution course of periodical response, quasi-periodical response, double-periodical bifurcation, chaos of the system response is analyzed.(3). It is deduced that the general differential equation of bending-torsional-pendular coupling vibration about rotor with the gyroscopic moment. On the basis of this equation, the general differential equations of coupled bending, torsional and pendular nonlinear vibration about rotor with unbalance character and rubbing character are deduced.

2建立了具有非线性刚度的转子系统在非稳态非线性油膜力作用下的径向碰摩动力学微分方程，并应用含高阶余项的非线性动力方程的线性化数值法研究了此类系统响应的复杂动力学行为，利用转子响应的分岔图、最大Lyapunov指数曲线、Poincaré截面映射、时域波形、相轨线、轴心轨迹、幅值谱等图形分析了系统响应的周期运动、拟周期运动、倍周期分岔、混沌等运动形式的转化与演变过程，重点研究了非线性刚度、转子转速、偏心质量等系统参数对碰摩故障转子系统的分岔和混沌行为的影响。

The main reason of wind vibration is a pulsant part of nature wind, unremitting vibration may bring large distortion and stress in the structure, and at the same time, it will bring fatigue damnification to the structure.

自然风中的脉动风分量是引起结构风激振动的主要因素，持续的振动可引起建筑幕墙结构产生较大的变形及应力，同时引起结构的疲劳损伤。

AR model in linear filter theory is adopted to simulate pulsant wind. Combined with some typical cable-membrane structures, research on self-vibration of the structure has been conducted. Based on the previous work, the influence caused by the vertical wind component on the membrane roofs has been analyzed in time domain. It includes the vibration laws of the structure under separate horizontal wind component, separate vertical wind component and the collective horizontal wind component and vertical wind component. Significant conclusions have been drawn from the analysis.

然后本文采用线性滤波器法中的AR模型对风速场进行了模拟；之后又结合典型的张拉索膜结构研究了膜结构的自振特性；在此基础上，本文研究了索膜结构在竖向脉动风影响下的风振响应特性，其中分别研究了张拉索膜结构在单独水平风，单独竖向风以及水平风和竖向风共同作用下的振动规律，得出了有关重要结论。

A uniform mixture of silicon powder (granularity≤0.044 mm) and polyvinyl alcohol solution (PVA,5 wt%) in response to a certain proportion was prepared.After sieving,prilling and vibration,the mixture was packed.Effects of the vibration frequency (14～50 Hz) and time (10~230 s) on packed density of powder were studied.

摘 要：将Si粉（粒度≤0.044 mm）和聚乙烯醇水溶液(聚乙烯醇质量分数为5%)按一定比例混匀，过筛造粒后，振动装料，研究了振动频率（14～50 Hz）和振动时间(10~230 s)对粉料填充密度的影响。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷