频率函数

But, in the natural and artificial signal, a lot of signal phases don\'tvary linearly with time, for example, we usually use chirp signal in the radar technology,frequency step signal, linear modulation component of the ground echo in the SARtechnology, linear modulation component of the moving target echo, linear modulationcomponent while the airborn radar detecting the moving target, etc.

在自然界和人工信号中，许多信号的相位变化并不是随时间一次方变化，如雷达技术中常用的线性调频信号，频率步进信号，另外，SAR 技术中，地面回波所含有的线性调频分量，ISAR技术中，运动目标的回波所含有的线性调频分量，机载雷达探测运动目标时的线性调频分量，等等；傅里叶变换对此类信号分析所得的结果是信号在不同频率点上的能量分布，即信号在基函数上的投影。

Put forward is a new method of skin effect correction based on function relationship between the real part of apparent conductivity against frequency and true formation conductivity in uniform formation condition.

根据均匀地层感应测井视电导率实部与频率和地层电导率的函数关系提出了一种双频率校正与归一化校正相结合的趋肤效应校正新方法。

The Green's tensor in frequency domain for cylindrical layered media was deduced from the 3-D Green dyadic for homogeneous media according to the propagation laws of waves in layered media,then the Green's tensor in spatial domain can be achieved with Fourier transformation ,which is a singular integral of wave-number.

根据分层介质中波的传播规律，由均匀介质中的三维张量格林函数得到频率域中柱状分层介质的张量格林函数表达式，经过傅立叶变换，可以得到空间域的格林函数，它是一个关于波数的奇异积分。

The Green's tensor in frequency domain for cylindrical layered media was deduced from the3-D Green dyadic for homogeneous media according to the propagation laws of waves in layered media,then the Green's tensor in spatial domain can be achieved with Fourier transformation,which is a singular integral of wave-number.

摘要根据分层介质中波的传播规律，由均匀介质中的三维张量格林函数得到频率域中柱状分层介质的张量格林函数表达式，经过傅立叶变换，可以得到空间域的格林函数，它是一个关于波数的奇异积分。

Applying energy variation principle, we give equation s defining parameters in flexural function, stability equation , frequency equation , and general formulae of minimum critical force and minimum eigenfrequency as well.

应用能量变分原理，给出了确定挠曲函数中待定参数的方程，以及稳定性方程和频率方程，给出了求最小临界力和最小固有频率的一般公式。

Fourier's theorem : any periodic function can be expressed as a sum of sinusoids of appropriate amplitudes and frequencies.

付氏理论：任何周期函数均可以表示为一组正弦函数的和，正弦函数具有合适的大小和频率

The equilibrium geometry,force constants and vibronic frequencies of the SiO2 molecule with linear structure have been optimized by using the Gaussian03 with B3P86/cc-PVTZ; The total internal partition sums were calculated for silicon dioxide with the product approximation. For rotational partition sums Qrot, the centrifugal distortion corrections are under consideration.

应用Gaussian03程序，在B3P86/cc-PVTZ水平上，对二氧化硅分子线性结构进行优化计算，得出其平衡几何构型、力常数和谐振频率等性质参数；采用乘积近似法构建模型计算了二氧化硅分子从20-6000K的总配分函数，其中转动配分函数考虑了离心扭曲修正，振动配分函数采用谐振子近似。

For unexploded ordnances, the four dimensional unexploded ordnance scattering function of slant range, azimuth, frequency and aspect angle is firstly estimated via the SWD. Secondly, the amplitude information of the multi-aspect feature in different frequencies is extracted, and the spatial distribution information of multi-aspect feature in different frequencies is quantitative described using the Hu moment invariants further.

对于未爆物目标，首先利用SWD得到未爆物斜距-方位-频率-方位角四维散射函数估计，然后在提取了不同频率下的多方位特征幅度信息的基础上，利用Hu不变矩进一步定量描述未爆物不同频率下的多方位特征空间分布信息。

Keyboard function set through waveform type,frequency,amplitude,duty cycle,and other parameters of a signal to the microprocessor 89C51 control,MAX038 generated by the various signals,In this process,four-channel signal through D/A converters have simulated voltage and current,It transported up through the analog signal amplification,it enters the frequency MAX038 coarse-IIN,fine-tuning FADJ end,the duty cycle control-DADJ. In its COSC port received a three relays and oscillation frequency capacitance as a choice.

通过键盘设定函数波形种类、频率、幅度、占空比等参数的一个信号进入单片机89C51控制，由MAX038产生各种波形信号，在此过程中信号通过四通道D/A转换器产生模拟电压和电流，它再通过运放将模拟的信号放大，它进入MAX038的频率粗调端IIN、微调端FADJ、占空比控制端DADJ、在它的COSC端口接一个继电器和三个振荡电容作为频率选择。

Base on the analysis, the interface between a nonlinear lefthanded material and a righthanded material can support both forward TE surface waves and backward TE surface waves under certain conditions.

针对电磁波在非线性左手系材料中的传播性质，分别研究了左、右手系材料界面以及两左手系材料界面上非线性TE表面波的传播行为讨论了导波的频率特性、色散关系以及群速度随频率的变化规律分析表明，两种界面上的非线性TE表面波均存在频率通带和禁带，且带宽是传播功率的函数揭示了在一定条件下，左、右手系材料界面上既可以支持正向传播的非线性TE表面波，也可以支持反向传播的非线性TE表面波；两左手系材料界面上表面波的传播性质因材料参量的变化差异较大，一定参量条件下，该界面上仅支持反向传播的非线性TE表面波。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。