频带

Studied every acoustic and vibration characteristics of vehicle system making use of the SEA car model that had been established. Utilizing the specialty of SEA, contrasted the acoustic contributing of panel in every frequency bands by comparing the radiant energy into cab directly with creativity. Compared the effects of every type of factors on the interior acoustic environment of car.

七、利用建立的统计能量分析模型进行车辆系统各个声振特性的分析，研究车辆行驶速度和行驶路面的等级等因素对车内声学环境的影响；利用统计能量分析方法的特点，创造性地通过直接计算仿真实际工况下各个部件对车内辐射能量的对比进行板件各频带声学贡献的分析。

This invention discloses a duplexer and a multiplexer of the communication system and a method to realize them on a PCB circuit, which applies a 3db bridge and a low pass filter to constitute a hopstreet duplexer without waste band channels, in which, the signals are shunted and combined by the design of the circuit structure and power distribution of the 3-db bridge and phase offset function, the band filter of the low pass filter and the reflection function of a stopband to make up of a costless duplexer in theory to merge the two channels of different frequencies and reduce loss to increase volume and working bandwidth, then a multiplexer is formed by cascading multiple duplexers.

本发明涉及通信设备，公开了一种通信系统双工器和多工器以及双工多工方法，使得双工器和多工器能够在PCB电路上实现，并且体积小、损耗小、成本低、容量大。本发明中，采用三分贝电桥、低通滤波器构成无损耗频带信道合路的双工器，其中通过电路结构的设计并利用三分贝电桥的功率分配和相位偏移功能将各路信号进行分路和组合，利用低通滤波器的频带滤波和阻带反射功能联合三分贝电桥构造一个理论无耗的双工器，使两路不同频率的信道合路，降低的损耗、提高容量和工作带宽。通过多个上述双工器的级联构成多工器。

A typical simulated signal and real-life vibration fault signal measured from a turbine generator unit were used to test this method.

通过对冗余提升小波分解得到的近似信号和细节信号采用傅里叶变换的方法消除了与其对应频带无关的频率成分，以突出相应频带信号的时域特征。

The band-width and the amplitude of the tillings are much different so that the coefficient can not represent the strength of signal components in different tillings exactly.

每个时频原子所代表的频带宽度不同，频带的响应增益也存在显著差异，使得子波或子波包分解系数难以准确反映该时频单元内信号分量强度。

A new method for a utomatically adjusting the spindle velocity is proposed in the paper. The method juges the extreme point of out-of-focus signal and calculates the time intervals between the adjacent extreme points by means of the characteristics of out-of -focus signal, and finally estimates the band of the out-of-focus signal.

本文提出了利用离焦信号的特点，判断出离焦信号的极值点，并计算相邻极值点之间的时间间隔，最终估算出离焦信号频带，并依据离焦信号的频带自动调节主轴速度的新方法。

In consideration of human hearing system′s frequency selectivity,the effects of thickness of coupling plate on critical-band level were also explained.

在考虑了人类听觉对频率的选择性接收的前提下，研究了参与耦合的板的厚度对特征频带声强级的影响，讨论了从特征频带声强级到响度的转换过程。

As a scale to measure precision and reliability, error analysis plays a very significant role in near field measurement in time domain.

随着现代通信技术和雷达技术向宽频带方向的迅速发展，短脉冲天线和超宽带天线获得了广泛应用，对与之相对应的天线测试技术也提出了更高的要求，传统的频域天线测试系统测试的频带有限，对超宽带天线测量效率较低，这就需要将频域近场测量扩展到时域近场测量。

The time-history velocity response signal of pile can be decomposed by Sym wavelet. The power spectrum value can be extracted from some specified spectrum range. These values from one signal makes up the characteristic vector representing this signal. The relationship between characteristic vector of pile and pile defect type can he established by using BP artificial neural network. Abundant time-history velocity response signals of pile can be acquired by numerical simulation method.

利用Sym小波对基桩速度响应时程曲线进行小波分解，对指定频带上的信号分量进行特征值提取，提取的特征值为反映各频带范围内体现能量分布的功率谱均值，提取的特征值可构成反映信号特征的特征向量，同时利用BP人工神经网络的非线性映射特性建立特征向量和基桩缺陷类别之间的一种对应关系。

There is a spectral band with the same center-frequency as that of the incidence pulse and two wider sidebands.

对聚合后光脉冲的频谱进行了分析，除了观察到与入射脉冲相同的中心频带外，还存在两个频带较宽的边带。

In addition, there are two strands of the head is also black, and are rust, rust can be seen because of lead wire resistance increases, resulting in the signal can not be smooth, telephone through the audio signal, the low band signal can also only phone, there is always the voice of flap, and the use of the ADSL band signal is relatively high, head through the rust on it is very difficult, leading to slow or stop signal transmission.

此外有两处绞合的线头处也发黑了，都是锈，可见正是因为导线生锈导致电阻增大，导致信号不能畅通，电话通过的音频信号，频带低，信号还能通过，只是电话里老是有啪啪的声音，而ADSL的信号使用的频带比较高，线头生锈了就很难通过，导致信号传输变慢或者断流。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。