查询词典 cartesian coordinate system

This coordinate system is in a way a generalization of Cartesian coordinates in Euclidean space.

这种坐标系统可以看成Euclidean空间的笛卡尔坐标的一种泛化。

It is shown that in Jameson's algorithm is not an orthogonal stream-lines coordinate system, but a local stream-lines coordinate system instead. Nevetheless, because of the finite-difference discretization in Jameson's scheme is not carried out along the direction of s and n, but along the Cartesian coordinates, the analysis on all terms of the full potential equation in Cartesian coordinates reveals that his scheme does take a back-ward difference along the streamwise exactly at all points in the supersonic flow region.

表明其所采用的坐标系不是真正的正交流线坐标系，而是局部流线坐标系；同时由于Jameson方法并不对s，n进行差分离散，而是在原笛卡尔坐标系下作差分离散，对笛卡尔坐标系下的全位势方程中的各项的分析表明，Jameson方法恰好能做到在超音速点沿真正的流线方向作后差分。

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。

One of three axes in a three-dimensional Cartesian coordinate system.

有三个以倾斜的角度交叉的不同晶轴。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。