二次的

The result shows: the maximum of the exchange bias field moves towardsthe easy axis with increasing the biquadratic coupling field or bilinear coupling field;additionally, the oscillations of the curves for the angular dependence of exchangebias field become weak and gradually resembles the sine function with increasing thebiquadratic coupling field.

结果发现：双线性耦合或双二次耦合的增加都可使交换偏置场的最大值位置向易轴方向靠近，并且双二次耦合的增加使交换偏置场随外磁场的角度变化曲线的振荡也随之减弱，变为类似于正弦函数的图象。

A new non-linear quadratic programming Bayesian prestack three-terms inversion method is developed; Firstly, this method is based on Bayesian parameter estimation theory, Gaussian distribution is used for likelihood function and modified Cauchy distribution is used for prior distribution; Secondly, covariance matrix is used to describe the degree of correlation between the parameters; rock physics relations are used to constrain the inversion results; at last, this method is transformed into non-linear quadratic programming problem, and inversion results are acquired under several constraints.

本文提出了一种基于非线性二次规划的叠前三参数反演方法。首先基于贝叶斯参数估计理论，假设似然函数服从高斯分布，并使待反演的参数服从于改进的Cauchy分布，从而提高了反演结果的分辨率；其次用协方差矩阵来描述参数间的相关程度，进一步提高了反演结果的稳定性；最后将问题转化为一个非线性二次规划的求解问题，并在多种约束下得到问题的解。

Accoring to the polar theory of conic section, the characteristics of geometrical graphics concerning the conic section is discussed from following three aspects:the conbination of Point and line, harmony of point range and pencil of line , trace of point and enveloping of straight line.

本文根据二次曲线的配极理论，从点、线的结合性，点列和线束的调和性，点的轨迹和直线的包络三方面研究与二次曲线有关的几何图形的性质。

Another new spatial 3-RPS parallel pyramid manipulator mechanism is studied. The principal screws of this mechanism under three different configurations are identified by means of the conic section and the quadric degenerating theory, respectively. The planar conics representing the relations between the pitches of the output twists and the three linear inputs are described, and the three-dimensional distribution of the axes of all the twists with the same pitch is illustrated under each of the configurations.

研究了另一种新的空间三自由度3-RPS并联角台机构，分别用二次曲线和二次曲面分解法识别该机构在三种位形下的主螺旋，绘制了其在每种位形下的输出运动螺旋的节距与输入之间的平面图以及具有相同节距的所有运动螺旋轴线在每种位形下的空间分布的立体图。

The strategy and controller are coming from combined analysis of combustion mechanism, generation mechanism of pollutants, influential elements, present application status of PID control method in combustion, as well as sum-up of controlling experience and contradistinctive researches of control strategies. It is shown that this method, when applied to furnace temperature controlling and activated-sludge process, is able to ensure controlling objects tracking in the presence of varying operation conditions, as verified via computer simulation. The thesis consists of chapters as following: Chapter 1 generalizes the research objective and brings forward the inferior theme; generation mechanisms of pollutants

本论文由以下章节组成：第1章对研究课题作了综述，提出了研究的子课题；第2章分析探讨污染物生成机理及二次污染物产生的条件，研究了控制污染的工程控制策略；第3章分析研究了仿人智能控制基本理论及其优越性；第4章通过仿真实验验证了仿人智能控制算法在炉膛温度控制中的有效性；第5章分析研究了有效防止二次污染的烟气处理方法；第6章通过仿真实验验证了仿人智能控制算法在废水生化处理中的可靠性和有效性；第7章总结了全文研究工作并对今后的工作作了展望。

We know that the solutions of quadratic, cubic and quartic can be expressed by radicals. As to the solution of the quintic which has became an issue for past two or three hundred years, it was not solved until 1832 a great young Mathematician of French named Galois who recommended group theory that proved a polynomial of degree 5 and over 5 can't be solvable by radicals.

中文摘要我们知道二次、三次及四次的方程式都可以用根式表示，至於五次方程式的解迟迟无法解决，这个问题持续了两三百年，直到1832年，一位法国青年Galois在其决斗前夕，在他的遗书中，这位伟大的青年数学家引进了群的理论，证明了：五次及五次以上的方程式，不可能有公式解。

Using the relations between harmonic conjugation elements,we can determine the relations between polar point and polar line more widely.

度量几何中圆的切割线之间所确定的数量关系，推广到射影几何里一般二次曲线中，利用调和共轭元素之间的关系，更广泛地确定了极与极线的相互关系，着重介绍了二次曲线的度量性质与射影性质的内在联系。

In order to improve the security, a signature scheme based on two hard problem assumptions is proposed. The security of the scheme is based on the difficulties of simultaneously solving the elliptic curve and quadratic residue. A attacker can't forge the signature of messages even if a attacker can solve theelliptic curve discrete logarithm problems or quadratic residue problem in the scheme.

为了提高签名的安全性，本文对Wang等人提出的签名方案进行改进，提出了一个基于椭圆曲线离散对数问题和二次剩余问题的数字签名方案，并对该方案的安全性进行分析，指出在椭圆曲线离散对数问题或二次剩余问题可解的情况下，攻击者也无法伪造消息的签名。

A first order quasi phase matched periodically poled LiNbO 3 for SHG with 6.5 μm period, 12 mm length, 10 mm width and 0.5 mm thickness has been successfully fabricated by applying an external electric field at room temperature from an high pulsed voltage generator. About 18 mW of CW 0.532 μm green light was obtained pumped by an 1.1 W of CW 1.064 μm Nd∶YAG laser with end coupling, which corresponds to 1.6% power conversion efficiency.

通过高压脉冲电场极化，制备了周期为6.5 μm、长为12 mm、宽为10 mm、厚为0.5 mm的一阶准相位匹配周期性极化铌酸锂；由1.1 W连续1.06 μm Nd：YAG激光器抽运，在5°时产生了约18 mW、0.532 μm的倍频连续绿光，其对应的二次谐波转换效率约为1.6%，二次谐波的归一化转换效率约为1.5% cm-1W-1，相当于79%的周期性极化铌酸锂的理想非线性系数。

The advantages and limitations of every kind of methods for calculating the failure probability is reviewed. The frist order reliability method, the second order reliability method and many kinds of boundary method have achieved remarkable success and formed nature fields of reliability. However, the precision of these methods decrease as the increase of complexity of problem. The numrical methods are versatile, except numerical intergration is only adaptable to special problems which have small number variables and regular intergral domain. Particularly, the advanced variance reduction techniques own the following character: high precision and a small amount computation. But some questions remain to study in the future because only an initial work about these techniqes is developed.

全面评述了计算失效概率各种方法的优点和局限性，其中经典的解析法包括一次可靠性方法、二次可靠性方法、一阶边界法、Vanmarcke上边界、PENT上边界和Ditlevsen二阶窄边界法，这些方法对于多设计点、变量较多且相关、密度函数不是正态以及极限状态方程较复杂的情况，其计算精度较差；而已有的数值方法却是具有较好的通用性，其中除数值积分法只对变量较少、积分域较规则的特殊问题适用外，各种数值模拟方法均具有较广的适应性，特别是各种改进的方差减小技术，精度高、计算量小，但由于其处在研究的初级阶段，还有许多问题有待于解决。

Plunder melds and run with this jewel!

掠夺melds和运行与此宝石！

My dream is to be a crazy growing tree and extend at the edge between the city and the forest.

此刻，也许正是在通往天国的路上，我体验着这白色的晕旋。