极坐标图

The influences of decay coefficient of the cavity and the intensity of the field on the phase distribution as well as its fluctuation are discussed.The results show:if there is absence of the phase damping,the phase distribution oscillates with the period π/λ.It presents single leaf at t=nπ/λ,but it splits into multi-leaf construction during the evolution period due to the interaction between the field and the atoms.

结果表明：当腔不存在损耗时，光场相位分布概率以π/λ作周期性振荡；且在t=nπ/λ时刻，光场和原子是退纠缠的，相位分布概率曲线在极坐标图中呈单叶型结构；但在演化周期内，由于光场与原子的相互作用相位分布概率曲线会劈裂为多叶型结构。

by using the software mathcad, the simulative calculation on water quality equalization has been made on a typical water sample. five kinds of mathcad worksheet used commonly the compiling method of mathcad worksheet and the simulative calculation procedure for the minimum effective volume of the equalization basin is presented. the reason for the subtle different in the results of different method is also explained. at last the author shows us the function of water quality equalization by polar diagram.

环境摘要：利用mathcad软件对一个典型水样进行了水质均化的模拟计算，给出了五种常用均质过程模拟算法的mathcad工作表，介绍了mathcad工作表的编制方法及水质均化池最小有效容积的模拟计算步骤，说明了不同模拟算法的计算结果存在细小差别的原因，以极坐标图显示了水质均化的作用。

Firstly, the basic character of the remote filed eddy current is simulated and analyzed in case of two-dimension axial symmetry which approves the existence of remote filed eddy current phenomenon; the full circumferential defect model is investigated to approve the feasibility of using the RFEC techniques to detect the position and depth of defect; the pit corrosion、circumferential and axial crack models are simulated, and the defect character based on voltage plane polar plot and the changes of phase and amplitude are analyzed to supply the standard for defect reconfiguration.

首先，在二维轴对称情况下仿真与分析了远场涡流的基本特性，证实了远场涡流现象的存在；对全周向缺陷的远场涡流检测进行了详细研究，证实了远场涡流检测缺陷位置和深度的可行性；对点状腐蚀、轴向与周向裂纹三种非轴对称缺陷进行三维有限元仿真，利用相位差和幅值变化曲线与电压平面极坐标图对缺陷特征进行分析，为缺陷形状重构提供了依据。

On the basement of conventional direct fan-beam reconstruction, this paper gives a newly improved algorithm-"fast filtering-backprojection". This method utilizes the symmetrical circle geometry to sample projection data, and reconstructs image on the Polarcoordinate firstly, then translates this reconstructed image onto the cartesian coordinate system with two interpolating operations so that the computer can show the result image on the VGA screen. This algorithm rebates the calculating backprojection greatly, and shortens a few times of reconstructing time than same kinds of means. With the size of image enlarging, the reconstructing time abates with 2 exponent times. In addition, according to the idea of parallel-beam, we rearrange the fan-beams and reconstruct image using parallel-beam method fastly. The rearranging constraint condition is given here.

本文首先在传统的扇束直接重建方法的基础上，提出了一个改进的快速滤波反投影重建算法，它利用旋转采集投影数据的圆周对称的几何关系，先在极坐标系统内进行图象的重建，然后通过两次内插运算再将图象转换到计算机显示方式下的笛卡尔坐标系中去，该方法将以往的直接重建方法中的反投影时所需的运算大大降低，并将重建时间比同类方法缩短了几倍，而且随着重建图象的尺寸的增大，重建时间以2的指数次方倍相对缩短，并获得了较好质量的重建图象；另外，又根据平行束投影重建图象的思想，对扇形射束进行了重排，然后利用平行束重建图象的方法进行扇束的重建，并推导了&扇束重排重建图象&方法的约束条件。

Based on the inertial navigation system , the influences of the excursion of the inertial navigation system and the measurement error of the wireless pressure altimeter on the rotation and scale of the real image are quantitatively analyzed in scene matching.

在惯性导航系统中，定量分析了景象匹配过程中惯性导航系统漂移和无线电气压高度表测量误差对实测图的旋转和尺度所造成的影响，引入了对数极坐标变换。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。