查询词典 frequency response

This thesis is based on crane dynamic theory and finite element theory, and utilized software platform of ANSYS. It realizes model analysis and transient analysis of steel rope and bridge structure. The data and conclusion offered effective method to bridge crane design. The thesis mainly includes:According to crane dynamic theory, established relevant dynamic model, and analyzed the dynamic properties of the bridge structure of the bridge crane, including the natural frequency, the model shape and the dynamic stress. A way to analyse the dynamic response of the bridge structure of the bridge crane which takes into account the dynamic properties of the steel rope pulley block has been explored successfully.

本文基于有限元理论和起重机动力学理论，以有限元分析软件ANSYS为平台，实现了计算机对钢丝绳系统和桥架的模态分析和瞬态动力学分析，得到的分析数据和结论对桥式起重机动态设计提供了有效的手段，论文主要内容包括：根据起重机动力学理论，建立了相关动力学模型，并对桥架结构进行动态性能分析(包括固有频率、振型以及动应力)的分析，探索出一种考虑钢丝绳滑轮组的动态特性在内的桥式起重机桥架结构动态应力分析的方法。

The thesis mainly includes: According to crane dynamic theory, established relevant dynamic model, and analyzed the dynamic properties of the bridge structure of the bridge crane, including the natural frequency, the model shape and the dynamic stress. A way to analyse the dynamic response of the bridge structure of the bridge crane which takes into account the dynamic properties of the steel rope pulley block has been explored successfully.

本文基于有限元理论和起重机动力学理论，以有限元分析软件ANSYS为平台，实现了计算机对钢丝绳系统和桥架的模态分析和瞬态动力学分析，得到的分析数据和结论对桥式起重机动态设计提供了有效的手段，论文主要内容包括：根据起重机动力学理论，建立了相关动力学模型，并对桥架结构进行动态性能分析（包括固有频率、振型以及动应力）的分析，探索出一种考虑钢丝绳滑轮组的动态特性在内的桥式起重机桥架结构动态应力分析的方法。

By practical engineering case,numerical analysis is done,and the natural frequency and the response to impact of the system are obtained.The numerical results show that the elastic deformation of the raft body will affect the dynamic character of the system,and the proposed model is more precise and judicious in engineering application.

结合具体的算例，求出了弹性浮筏隔振系统的固有频率和对不同冲击激励的响应，指出了筏体的弹性变形对系统动力学性能的影响，揭示了弹性模型的全面性和合理性。

Results In shuttle box test Stimulus Frequency, Stimulated Time and Active avoidance Response Time of the rats were reduced respectively in Sermion, Hexue Yizhi Formula （1 mL/100 g）, Hexue Yizhi Formula （2 mL/100 g） groups than those in NS group.

NS组海马细胞体积变大、核变小、有核仁消失和核固缩：除假手术组正常外，其余各组海马细胞层次有减少，但细胞排列比较密集、细胞形态尚可。

Wavelet packet decomposition can decompose high-frequency part of signal. In order to obtain the energy rate index of each node this paper advances apply wavelet packet decomposition method to node response of pipe. And then use statistics method to analysis the energy rate index indicator of various nodes in pipe. Results show this method not only can detect the locations of damage in pipe, but also can get a preliminary study for quantify the damage degree damage of pipe.

本文提出将小波包分解方法应用于管道的节点响应，得出各个节点的能量率指标，并利用数理统计方法对管道上各个节点的能量率进行统计分析，结果表示该法不仅能确定管道的损伤位置，而且还能对管道损伤程度的定量分析作一个初步的研究。

Nature frequency and earthquake response of the structure are determined through shaking table test.

通过振动台试验，确定了模型的自振频率，多种地震波输入下的结构加速度反应和位移反应，对结构的抗震性能进行了综合评定。

Based on one-cycle control having such merits as anti-perturbation of source, fast dynamic response, robustness, constant frequency, but when converter works in light load its power factor becomes very poor. The modified OCC was proposed, adopting feed-forward compensation control improves influence of power factor at light load, further study adopting independence saw tooth wave completely eliminate influence of power factor at light load.

基于单周期控制有源前端变换器具有抗电源扰动能力强、动态响应快、鲁棒性强、恒频控制等优点，但在轻载时变换器的功率因数变差，提出了改进OCC策略，采用前馈补偿控制改善轻载时对功率因数的影响，进一步研究采用独立的锯齿波电路完全消除轻载时对功率因数的影响，建立改进OCCAFE变换器的数学模型。

Visual evoked potentials of twelve healthy volunteers were recorded under two conditions including normal state and one night's sleep deprived state, and were wavelet transformed to time-frequency values between 30 to 60 Hz. The inter-trial phase coherence of prefrontal lobe and the evoked response phase coherence between prefrontal lobe and occipital lobes were calculated.

在正常状态和一夜睡眠剥夺状态下提取12名受试者的视觉ERP，进行30~60 Hz的小波变换，以此计算前额叶区域的导联内相位相干，以及枕叶和前额叶之间的相位相干性。

Mm was almost independent of the ray intensity when the ray intensity was more than 100 Bq, but decreased evidently when the response frequency of the measurement system was low and the ray intens...

实验还发现mm几乎与物体的厚度和状态无关。采用GTS2000系统既能测量射线强度，又能测量射线能谱，借助能谱可直观地选定单能峰值g射线所在的上下阈值，有助于提高测量系统的稳定性。

At the same time, pattern recognition has been used for abstracting characteristics、predicting the life and evaluating the properties of engine. This research contributes toward global diagnosis for the diesel engine in eight ways.(1) Put forward"the Arithmetic of distinguish the period automatically using auto-correlation method";(2) Separate the waves of continuous knocks using WV distribution;(3) Propose"the logarithmic spectrum approximate method"to analysis the response of the knock between the steel and steel;(4) Discuss the relationship between the time-frequency distribution and timescale distribution in detail, and give the principle of classification;(5) Use the wavelet method to analysis the pressure signal of exhaust、suction;(6) Use the shape of vibration signal to analyse the working situation of cylinder;(7) Use the pattern recognition to select the good samples and abstract the effective characteristics;(8) Develop the model of total properties evaluation and life prediction.

本文在广泛的、深入研究的基础上，应用多种信号处理手段来分析处理数据，同时利用模式识别方法对故障的特征提取、寿命预测以及性能评价作了探讨，本文进行了以下几项工作：（1）提出了基于自相关自动周期识别算法的柴油机振动信号预处理策略；（2）提出了基于WVD分布的连续撞击响应信号的分离策略；（3）提出了基于对数谱拟合方法的钢—钢撞击响应求解模型；（4）提出了基于波形分析的非正常燃烧振动信号的诊断模型；（5）提出了基于小波细节信息的进气压力信号和曲轴箱压力信号的诊断模型；（6）提出了基于小波近似的喷油正时信号中燃烧位置的自动定位；（7）提出了基于统计模式识别方法的故障诊断知识的自学习与自组织策略；（8）提出了基于特征压缩思想的柴油机总体性能评价及寿命预测模型。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐