矢

For the surgical treatment of lumber spondylolisthesis, the major goal is spondylolisthesis could restore normal mechanics and saggital curve of the lumber spine, relieve neural compression and improve the funtion.

对于腰椎滑脱的病人，最基本的目的是恢复脊柱的生物力学功能，解除对神经牵拉和压迫，恢复正常矢状面曲线，改善功能。

You shall not fear the terror of the night nor the arrow that flies by day

你不必怕黑夜惊人的颤栗，也不必怕白天乱飞的箭矢

Bows require dexterity for quick assessment and steady aim as well as for the ability to rapidly nock and loose arrows .

使用弓需要尽量高的敏捷，敏捷越高，击中率约高，也能更快的再次发射箭矢。

It is significative to study the circumgyration of noncommutative ring and soliton solutions of noncommutative field theory.

这些基矢对于研究非对易环的旋转及非对易场论中的孤子解都有意义。

This paper presents a new rendering algorithm by the contrast between the Flat method, Gouraud method and Phong method, through which the color of each pixel can be figured out under the lighting model after the coordinates and normal of every corresponding point on the 3D-object surface have been calculated from the pixels in the range where the 3D-object is projected onto the photo, in order to provide each pixel a real color and get an image with strongest feeling of reality.

本文在对比研究了真实感图形生成中传统的Flat，Gouraud，Phong等明暗渲染方法后，提出了一种新的明暗渲染方法。在图像平面三维物体的投影范围内，由图像的像素坐标求出物体模型对应点的三维坐标及其法矢，然后对每个像素点根据光照模型来计算其明暗度。这种方法能够最大可能的保证图像中每一像素点明暗度的真实性，从而使所生成的真实感图像更加逼真。

The interpolate algorithms of three-order NURBS curve and double three-orders NURBS surface are presented. The expressions of partial derivative and normal curvature of NURBS surface are derived by the theory of differential geometry. The geometric characteristics of different curvature area of the free-form surfaces are analyzed in detail. All these work lays a theoretical foundation for constructing the cutter location calculating model of free-form surfaces NC machining. 2 On the basis of analyzing the methods of cutter path generation, the standard of evaluating the various methods of cutter path generation is presented. The method of generating cutter path with constant scallop height is presented for the first time.

本文以提高复杂曲面多坐标数控加工精度和加工效率为目的，在对国内外研究现状进行深入分析的基础上，对数控编程中各环节的关键技术问题进行了深入研究，主要内容包括以下几方面： 1 分析了复杂曲面各种造型方法的优缺点，给出了根据各种边界条件所确定自由曲面的NURBS表示方法以及三次NURBS曲线曲面反算算法；用微分几何理论推导了NURBS曲面的偏导矢及法曲率计算表达式；对曲面不同曲率特性区域的几何特征进行了深入分析，为建立复杂曲面的数控加工刀位计算模型奠定了理论基础。

This paper presents a novel triangulation algorithm based on the normal information of the surface and the Delaunay triangulation algorithm.

借助于曲面上的法矢信息和三维Delaunay三角剖分算法，该文给出了一种新的散乱点三角剖分算法。

Two optimal criteria of the vertex normal vector estimation are presented.

给出了一个判别二维多边形和三维多面体顶点法矢计算方法优劣的准则。

Objective:This study was designed to measure the angles of the acetabular abduction when facing the different pelvic obliqueness angles.

目的：通过对正常骨盆标本在骨盆歪斜不同角度时的髋臼外展角进行测量，得出髋臼外展角在骨盆绕身体矢状轴旋转时的变化趋势和规律。

Methods:The angle of the acetabular abduction of 21 pelvis all 42 hip joints were measured with the manual devices when facing the 9 different pelvic obliqueness angles.

手动测量21具骨盆标本共42髋在骨盆绕身体矢状轴向头侧和尾侧歪斜的9个不同角度时的髋臼外展角的度数。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。