反曲线

It is concluded that if the monatomic model of Chapter 3 is used the pair potential constructed by the former method cannot predict correct heats of solution, while the pair potential constructed by the latter method can predict the lattice constants, the bulk moduli and the cohesive energies of the Ll〓 superstructures formed by the two kinds of atoms within acceptable accuracy.

推广到合金的情况，提出了由某个二元超结构的结合能曲线和由稀极限溶解热反演埋入原子法的合金对势V〓的两种不同的方法。

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。

The quarter ellipse curve is used at upstream face of weir crest and intake side of surface hole, the downstream face of weir is linked with 1:0.7 slope section, then linked with ogee spillway, its radius is equal to 30m.

表孔堰顶上游坝面及进口侧采用1/4椭圆曲线，堰面下游接1：0.7的斜坡段，再接R=30m反弧段，并采用长隔墩布置方案。

Different biases can result in the opposite phase shifts of the impedance with respect to the applied signal. Neutral gas pressure affects the magnitude of the impedance, but does not change the shape of the frequency response curve. In addition, the position of the grid inside the vacuum chamber has little effect on the impedance.

结果显示栅网上的直流偏压对阻抗的影响很大，不同偏压可以使阻抗的频率响应反位相，气压对阻抗的大小有明显影响，但一般不改变频率响应曲线的形状，栅网的位置对阻抗几乎无影响。

The breakthrough curves for heavy metals of solidification sludge were obtained by flexible-wall permeameter and the hydrodynamic dispersion parameters were acquired by genetic inverse method.

5采用柔性壁渗透仪获得了固化污泥中重金属的穿透曲线，并采用遗传算法反演了固化污泥的水动力弥散参数。

Two T3 He and D3He reactions are chosen for generating the neutrons. The neutron beam is collimated with the multiplex shielding system. The source intensity is monitored by the proportional counter or semiconductor proton recoil telescope. The neutron response curves of ST-401 scintillators with thickness from 0.16mm to 2.00mm are measured versus neutron energy. The uncertainties of experimental results are discussed in detail.

选用T3He反应和D3He反应作为中子源，子源，中子束流采用复合屏蔽体进行准直，源强采用正比计数管和半导体望远镜进行监测，实验测量了厚度从0.16mm到2.00mm的八种规格薄闪烁体的能量响应曲线，对实验的结果的不确定度进行了分析。

It is simplified by approximating the radius of curvature, which provides the NURBS curves interpolators with good real-time performance.

该算法基于NURBS曲线的反算算法，通过合理的近似计算，对插补运算简化，保证了算法的实时性。

Based on the order number 10, the quadratic sum of residual error is 533%, the extrapolating result is wrong. But with the order number 9, the quadratic sum of residual error is 0.673%, the result is right

对於表面特定温度为θ(0， t)的曲线，测得其0.0129cm处的温度变化规律反推，选取阶数为10时，剩余误差平方和为533%，外推结果错误，选取阶数为9时，剩余误差平方和为0.673%，外推结果正确。

The surface of conventional engineering part is composed of simple analytical surfaces and four-boundary ruled surface primarily. Therefore a point cloud segmentation method based on those feature surfaces is proposed. Several algorithms to identify the simple analytical surface feature are investigated and discussed. The theory of fitting scattered point to B－Spline and Bézier surfaces is introduced and a fitting method based on four boundary and point set is also discussed. Moreover, anew method to recover the fix-radius rolling ball blend is proposed and discussed in detail.

常规工程零件的外表面中包含了大量的特征曲面，如简单解析曲面和四边直纹面，因此，本文提出基于特征曲面的的点云分割方法，研究几种识别简单解析曲面的算法；研究由点云拟合B－Spline和Bézier曲线的理论基础，总结曲面拟合的几种方法，提出一种反求定半径滚球圆角的方法。

The viscoelastic parameter identification and back analysis are carried out by using the multi-stage loading creep curves of granite and schist.

在此基础上，针对花岗岩及片岩两种岩石的室内蠕变分级加载试验曲线进行了流变参数的识别与反演。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新