yuyin

高分辨率要求系统具有大的带宽，瞬时带宽的增加必将提高系统对硬件的要求，本文采用方便灵活的步进频率波形信号。脉间频率步进波形通过子脉冲载频的步进变化来获得大的有效带宽，使成像具有高分辨率，采用加窗和补零方法提高信噪比，但该信号对目标径向速度非常敏感。采用补零方法提高距离取样分辨率，使距离像细化，并用公式说明了补零只能提高距离取样分辨率，并不能改变频率步进信号的距离分辨能力。该信号波形对目标径向速度的敏感，使目标能量分散到邻近的距离单元造成距离分辨率下降，如果不事先进行速度补偿，直接对回波信号进行逆傅立叶变换，将使所成一维距离像发生频谱展宽，并伴有距离像发生平移。本文证明了当目标有径向速度时仍采用对回波信号直接进行逆傅立叶变换的方法将使一维距离像发生频谱展宽并伴有距离像发生频移，从而严重影响了一维距离像的质量。(high-resolution requirements of the system with large bandwidth, the increased instantaneous bandwidth will improve the system of hardware, In this paper, a flexible and convenient step frequency signals. Pulse frequency step-pulse waveform through the carrier frequency step to achieve great changes in the effective bandwidth. make imaging with high resolution, increasing the window and fill methods to improve signal-to-noise ratio is, However, the signal on the target radial velocity is very sensitive. Using zero-distance sampling method to improve resolution, so that distance as refinement, and formulates a zero-distance sampling can improve resolution, does not alter the frequency of the signal from stepping resolution capabilities. The signal waveform on the target radial velocity sens)

说明：  二维FDTD程序计算近场模型，包括建模文件以及电磁场递推文件，入射角度为0°。模型时一个介质方柱。(The two-dimensional FDTD program calculates near-field models, including modeling files and electromagnetic field recursion files, with an incident angle of 0. The model is a medium square column.)

说明：  fluent的udf程序，可以计算pmv(Fluent's udf program can calculate pmv)

说明：  基2基4基8以及分裂基的fft算法，代码效率很高。是难得一见的好代码。应用范围很广。(Radix-2-4-based 8 and split fft-based algorithm, a high code efficiency. Is a rare good code. Application of a very wide scope.)

This FDTD 2D simulation based on Dennis Sullivan book s. Wave propagation in vacuum background using PML boundary conditions.

用于计算stewart 六自由度运动平台的正解问题(this program is designed for stewart platform。)

利用C语言实现MOORE-PENROSE广义逆矩阵的计算，经试验OK。(The realization of MOORE-PENROSE generalized inverse matrix is calculated by using the C language, through the test of OK.)

应用FORTRAN语言编写的通过方向应力张量与应力余弦张量求解主应力矩阵(Application FORTRAN language through direction cosine stress tensor and the stress tensor matrix solving the principal stress)

用MRT-LBM计算顶盖驱动流的程序，比LBGK方法更加稳定。(Codes for lid-driven flow with MRT-LBM, which is more stable than LBGK.)

读取csv文件的数据，按要求拉算出平均数(Read csv file data, calculate the average number required to pull)