查询词典 parabolic curve

First,The properties of the spherical Bezier Curvesproposed by Ken Shoemake(Spherical Bezier curve of first kind)are listed,such asEndpoint property,Symmetry property,Invariant property under solid motion,Spherical convex hull property,etc.,and the fact that this kind of spherical BezierCurve is devoid of subdivision property is pointed out;Based on subdivision,theconcept of a new kind of spherical Bezier curve(Spherical Bezier curve of secondkind)is proposed.This kind of spherical Bezier curve is continuous differentiable.Furthermore,generalization of Bezier curve on more comprehensive manifolds isdiscussed.2Spherical Chaikin algorithm and general spherical corner-cuttingalgorithm.

首先，文中列举了Ken Shoemake提出的点点生成的球面Bezier曲线(第一类球面Bezier曲线)的性质，如端点性质、对称性质、运动不变性质、球面凸包性质等，并指出这种球面Bezier曲线没有剖分性质；基于细分，文中给出了一种新的球面Bezier曲线(第二类球面Bezier曲线)的构造方法，指出这种曲线是连续可微的；作为这些理论的应用，文中改进了Ken Shoemake提出的球面插值曲线构造方法；进一步，文中探讨了Bezier曲线在更广泛的流形上的推广方法。2球面Chaikin算法和一般的球面割角算法。

This dissertation investigates the construction of pseudo-random sequences (pseudo-random numbers) from elliptic curves and mainly analyzes their cryptographic properties by using exponential sums over rational points along elliptic curves. The main results are as follows:(1) The uniform distribution of the elliptic curve linear congruential generator is discussed and the lower bound of its nonlinear complexity is given.(2) Two large families of binary sequences are constructed from elliptic curves. The well distribution measure and the correlation measure of order k of the resulting sequences are studied. The results indicate that they are "good" binary sequences which give a positive answer to a conjecture proposed by Goubin et al.(3) A kind of binary sequences from an elliptic curve and its twisted curves over a prime field F_p. The length of the sequences is 4p. The "1" and "0" occur almost the same times. The linear complexity is at least one-fourth the period.(4) The exponential sums over rational points along elliptic curves over ring Z_ are estimated and are used to estimate the well distribution measure and the correlation measure of order k of a family of binary sequences from elliptic curves over ring Z_.(5) The correlation of the elliptic curve power number generator is given. It is proved that the sequences produced by the elliptic curve quadratic generator are asymptotically uniformly distributed.(6) The uniform distribution of the elliptic curve subset sum generator is considered.(7) We apply the linear feedback shift register over elliptic curves to produce sequences with long periods. The distribution and the linear complexity of the resulting sequences are also considered.

本文研究利用椭圆曲线构造的伪随机序列，主要利用有限域上椭圆曲线有理点群的指数和估计讨论椭圆曲线序列的密码性质——分布、相关性、线性复杂度等，得到如下主要结果：(1)系统讨论椭圆曲线-线性同余序列的一致分布性质，即该类序列是渐近一致分布的，并给出了它的非线性复杂度下界；(2)讨论两类由椭圆曲线构造的二元序列的&良性&分布与高阶相关性(correlation of order κ)，这两类序列具有&优&的密码性质，也正面回答了Goubin等提出的公开问题；(3)利用椭圆曲线及其挠曲线构造一类二元序列，其周期为4p(其中椭圆曲线定义在有限域F_p上)，0-1分布基本平衡，线性复杂度至少为周期的四分之一；(4)讨论了剩余类环Z_上的椭圆曲线的有理点的分布估计，并用于分析一类由剩余类环Z_上椭圆曲线构造的二元序列的伪随机性；(5)讨论椭圆曲线-幂生成器序列的相关性及椭圆曲线-二次生成器序列的一致分布；(6)讨论椭圆曲线-子集和序列的一致分布；(7)讨论椭圆曲线上的线性反馈移位寄存器序列的分布，线性复杂度等性质。

The polarization curve is not sufficient for a reliable and unique validation of a PEMFC model since different parameters can lead to an identical polarization curve. A three-step validation approach is proposed for a complete and unique validation. These three steps are:(1) validated by the global polarization curve,(2) validated by the local current density distribution curve, and (3) validated by the cathode over-potential and anode over-potential versus current density curve. The results from the comparison of four flow-fields show that the PEMFC performance of the flow-fields decreases in order by interdigitated, metal foam, pin-type and parallel.

通过PEMFC参数敏感性研究发现，PEMFC性能受多种参数的影响，这些参数可分为非敏感性参数、敏感性参数和高敏感性参数；与阳极侧参数相比，PEMFC性能对阴极侧的参数更敏感；不同参数值的组合可以得到几乎完全相同的极化曲线，因此电池的极化曲线不足以用于验证数学模型的唯一性与可靠性；为验证PEMFC数学模型的唯一性与可靠性，提出了模型验证的三步法：极化曲线验证、局部电流密度验证和阳极总过电位与阴极总过电位验证。

As we all know, it is equivalent to the null controllability of a cascade system governedby two linear degenerate parabolic equations. Next, we study the null controllability of acascade system governed by a semilinear degenerate parabolic equation and a semilinear heatequation.

众所周知，这等价于两个线性退化抛物方程构成的耦合系统在单个控制作用下的零能控问题；接下来我们又考虑了一类半线性退化抛物方程与半线性热方程构成的耦合系统的零能控问题。

The results show that the oxidization weight increasing and oxidation time follow the parabolic law at 800℃, no surface oxidation film desquamates, and the oxidation rate is stable. While at boot, the oxidation kinetic curves approximately follow the parabolic law, oxide films begin to desquamate lightly and thickening, and the mass gains are about four times as those at 800℃.

结果表明，熔敷金属在800℃氧化时，氧化增重与氧化时间遵从抛物线规律，表面氧化膜无剥落，氧化速率较稳定；在1000℃氧化时，氧化增重与氧化时间近似遵从抛物线规律，表面氧化膜出现少量剥落，且氧化膜增厚，氧化增重是800℃氧化时的4倍左右。

Based on point explosion theory , the approximate analytical formulas of momentum coupling coefficient and impulse of cone and parabolic crafts are deduced. The results show that the total axial impact momentum for parabolic craft is larger than that of cone craft and it increases with the increase of half open angle.

以LSD/LSC波理论为基础建立了一个近似的理论解析模型，推导出圆锥形和抛物形飞行器获得的冲量及冲量耦合系数的近似解析表达式，公式表明冲量耦合系数随着半张角的增加而增加，同时抛物形飞行器要比圆锥形飞行器的动量汇聚效果好。

More than 30 papers have been published and 5 invention patents have been possessed. Major achievements include: 1 Completion of solar dish power system overall design and equipment commissioning; 2 Completion of parabolic trough power system overall design and equipment commissioning; 3 Parabolic trough concentrator overall design and instantaneous simulation of thermal-technical performance; 4 Overall design of heliostat and wind load simulation; 5 Quick evaluation methods for thermal performance of solar collector; 6 Design of dehumidifying air conditioner using solar evacuated air collector; 7 Research on radiation, flow, conduction coupling and heat exchange on complex ship surfaces

其主要学术贡献为： 1MW级太阳能塔式电站总体设计； 1完成了太阳能碟式聚光发电系统的总体设计和设备调试； 2完成了太阳能槽式聚光发电系统的总体设计和设备调试； 3槽式太阳能聚光器的总体设计与热工性能的瞬态模拟； 4太阳能聚光器定日镜的总体设计和风载荷模拟； 5了太阳能集热器热性能快速评价方法体系； 6太阳能真空管空气加热除湿空调系统的系统设计和设备定型； 7复杂船体表面的辐射、流动与导热耦合换热的研究。

This dissertation is devoted to the global existence and quench ing phenomena of the solution to a nonlinear parabolic equation of the mean curvature type and the blow-up conditions to another nonlinear parabolic equation.

本文研究了一类平均曲率型抛物方程解的整体存在性和解的熄灭现象及一类非线性抛物方程解的爆破条件。

This thesis is divided into six parts. The first chapter is preface, the current status of research in the inverse problems for parabolic partial differential equations is reported; the second chapter is "regularization methods for numerical differentiation and their applications ", in this chapter we investigate many regularization methods from a viewpoint of regularization theory and algorithm, some applications in the inverse problems for parabolic partial differential equations are given; the third chapter is "spectral regularization methods". Based on Fourier analysis, within the framework of regularization theory, we apply the spectral methods to some ill-posed problems. Many numerical experiments are done in order to show the validity of the methods; the fourth chapter is devoted to wavelet dual least squares method and a revised wavelet method; in the fifth chapter,we combine finite difference method with method of lines and apply it to the backward heat conduction problem in time; in the sixth chapter "identification problems for unknown source ", the essence and the degree of two problems related to source identification are pointed out, at the same time, some numerical methods are reported.

本文分为六个部分，第一章前言简要分析了国内外抛物型偏微分方程反问题的研究现状；第二章数值微分的正则化及其应用从正则化理论和算法的角度出发，考察了许多正则化方法，还给出了数值微分在抛物型偏微分方程反问题的一些应用；第三章谱正则化方法是在Fourier分析的基础上，在一般正则化理论的框架下，给出了这种方法在各种不适定问题中的应用，数值实验表明谱方法是有效的；第四章研究了小波对偶最小二乘方法和改进的小波方法；第五章主要研究了有限差分方法结合线方法在时间反向热传导问题中的应用；第六章是未知源识别问题，主要指出了两类未知源问题的不适定程度和不适定本质，同时报告了一些数值方法。

A kind of delay parabolic partial differential equation is studied. A numerical method is proposed by discrete skill. The numerical stability for this kind of delay parabolic partial differential is analyzed by interpolation method.

研究了一类时滞的抛物型偏微分方程初边值问题，利用离散技巧，提出了一种数值方法，然后在一定插值技术下分析了算法的稳定性。

Although translator has turned from being a crystal ball by which the original culture can unrestrainedly penetrate to another crystal ball by which the target culture can freely traverse, the translator's personal embodiment, in the process of cognitive act, are still absent in translation studies. Translators are still subjects without body or simply disembodied subjects.

译者虽然由原语文化可以自由穿透的玻璃球变成了译语文化可以自由穿越的玻璃球，但译者认知过程中的个体体验在翻译研究中依然缺席，译者依然仅仅是一个没有躯体体验的主体。

Chillingly, he claimed our technology is 'not nearly as sophisticated' as theirs and "had they been hostile", he warned 'we would be been gone by now'.

令人毛骨悚然的，他声称我们的技术是'并不那么复杂，像他们一样，和"如果他们敌意"，他警告说，'我们将现在已经过去了。