查询词典 frequency response

Firstly, based on the Duhamel integral and dynamic reciprocity theorem, the generalized Duhamel integral expression is written to a point in the half infinity space under moving load. Secondly, the train load is considered as a series of centralized loads with fixed distance. The dynamic response expression of a point in frequency domain and frequencywavenumber domain are derived out through the Floquet transform and Fourier transform under a moving load, and then the dynamic response of a point is gotten ...

以Duhamel积分为基础，首先应用动力互等定理，得到了移动荷载作用下，半无限大弹性连续介质空间上任意点的动力响应的广义Duhamel积分表达式；然后将列车荷载简化考虑为一系列具有一定间距的集中荷载，采用Floquet变换、Fourier变换等方法，得到了一个集中移动荷载作用下任意拾振点ξ的动力响应在频域和频率波数域内的表达式，进而由叠加原理得到列车荷载作用下的动力响应解；最后，通过算例说明该算法的适用性。

It has been shown that the red shift due to delayed nonlinear response time in frequency domain increases with the increasing of delayed nonlinear response time exceeds a certain value.

结果表明，脉冲在长波方向的自频移随非线性响应时间的增大先增大后减小，利用这种关系有可能获得非线性响应时间的信息。

If the excitation amplitude is constant and the excitation frequency is close to 3-times resonance frequency, the effect of the 3-times superharmonic resonance on the system response increases greatly.

当激励幅值不变、激励频率逐渐接近3倍超谐共振频率点时，3倍超谐振动成分对系统响应的影响逐渐增加，这表明立方非线性对系统的调节作用越来越强。

Due to the regulating by the cubnonlinearities, some parametric ranges in which 3-times superharmonic vibration or 1/3-times subharmonic vibration arises exist in the sytem. When the excitation frequency approaching 3-times or 1/3-times resonance frequency, the system response is stable and periodic .This fact shows that regulating action of the cubic nonlinearities on the vibration system is strong.

由于立方非线性对达芬系统的调节，系统存在出现3次超谐共振和1/3亚谐共振的参数域，在激振频率接近3倍或1/3倍派生系统的固有频率时，立方非线性对系统的调节作用越来越强，从而使动态响应成为稳定的周期性。

The phase of ω0 frequency fluctuates tempestuously. The resonance peaks of flexural and torsional vibrations response are present at 2/3ω0 1/2ω0 1/3ω0 and 1/4ω0 with three kinds cracked rotor models. Near 1/2ω0 frequency, quasi-periodic and chaotic motions maybe appear. Periodic, quasi-periodic and chaotic motions show on alternately when the rotating speed is near to 2/3ω0.Combined step-by-step integral method with traditional transfer matrix method, an increment transfer matrix method is put forward.

研究结果表明：各种故障情况下，华北电力大学博士学位论文弯振和扭振之间都存在祸合关系，但弯扭祸合振动一般不会威胁机组安全运行：在叶片丢失或滑环飞脱故障时，将产生很大的弯振，同时各转子扭振也将被激发出来，它以工倍频和前三阶固有频率为主；在各种电气故障情况下，各转子都很快被激励出较大幅值的扭振来，相应各转子弯振也发生一定的变化，但它的变化明显滞后于扭振，扭振和扭矩主要以前三阶固有频率为主。

The array consisted of 8 piezoelectric crystal sensors, each coated with an adsorptive material with unselective, but different response characteristics. The frequency shift data obtained from the array as the response to mixed vapour of common organic solvents of small molecular size were treated by using stepwise discrimination analysis, and five coatings that provided the maximum level of analyte discriminating ability were selected. The array constructed from these solvents was applied to recognizing alcoholic hydroxyl, carbonyl from other organic functional groups. The principal component analysis was applied to the original and autoscalled data. The two-dimensional display of the data showed well-defined clusters for solvents containing different functional groups separated from each other. The array was applied to identifying spirits and beverages.

该阵列由八个压电晶体传感器组成，每个传感器涂以具有广谱响应性能的不同吸附活性材料，阵列对常见小分子有机溶剂混合蒸气的响应频移数据采用逐步判别分析处理，选出五个供信能力最佳的判别变量，以此构成的阵列用于小分子有机溶剂混合蒸气中醇羟基、羰基与其它官能团的识别，并采用主成分分析法降维投影，在二维空间含相同官能团的物质聚为一类；阵列可用于酒类、软饮料的识别。

The study of spatial configuration and characteristics of pulsed-wire velocity probe shows that: the yaw-and pitch-response characteristics have a good behavior due to the asymmetrical arrangement of the prongs. Because the amplitude of sensor wire response signal changes with the flow velocity, the differentiated signal is selected to trigger a voltage comparator. The pulsing frequency is restricted to about 100Hz to allow the wire to cool between pulses. The first velocity probe with big acceptance cone has been developed in China, and the way of measuring the Reynolds normal and shear stress and application have been given in this dissertation.

对脉冲热线空间速度探针的空间结构及特性的分析表明：三根长支架平行且安置于同一平面的探针结构可以获得大的测量角和好的测量性能；由于传感丝的响应信号幅值随流速变化较大，故应采用微分法进行信号处理；对于5μm的传感丝由于散热时间基本不变，约为10ms，故脉冲发射的最高频率为100Hz；本文在国内首次研制成功了一种大测量窗的脉冲热线空间速度探针，并给出了测量雷诺应力的方法和实例。

A part of auditory neurons of inferior colliculus has characteriatics of multi-channel response, and the frequency of channel equal to the characteristic frequency of neurons.

小鼠下丘部分听神经元具有单通道反应特性，且通道的频率等于神经元的特征频率。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

To realize high positioning precision and rapic response, this paper provides a variable parameter filter technique to filt positioning noise and high frequency noise meanwhile keeping rapid speed response, this technique has lower filter stiffness and damp paremeter in static state and bigger stiffness and damp paremeter in movement state using variable parameter technique, accordingly to solve the contradictions of positioning noise and positioning speed.

为实现系统高精度定位和快速响应，本文提出了采用宏定位变参数滤波技术滤除宏定位系统高频噪声，同时保持系统高响应速度。

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