矩

A linear feasible direction algorithm is proposed to calculate reliability index of structure.

为克服当极限状态曲面方程非线性程度较高时应用一次二阶矩法求解可靠指标可能不收敛的问题，提出一种求解结构可靠指标的线性可行方向算法。

The main contents of this dissertation are as follows:(1) According to involved theories of ferromagnetics, the microscopic mechanism of domain structure is analyzed systematically; through the movement variation of domain structure, that is the movement of domain wall and rotation of magnetic moment, the magnetization process is illustrated in an applied magnetic field. Meanwhile, by the use of energy methods, a study is performed on influencing factors of domain movement including stress, dope, scattering field, etc. The influence of various energies is dealt with on the magnetic behavior and parameters of ferromagnetic material; the corresponding theories of the spontaneous magnetization and technical magnetization are also discussed.

本文以此为研究背景，通过理论分析和模型试验，系统地研究了钢结构全磁通应力无损检测技术的基本理论和应用方法，主要研究工作如下：(1)根据铁磁学的相关理论，分析了铁磁材料磁畴结构产生的微观机理，并通过对磁畴结构运动变化规律，即磁畴壁移动和磁矩转动规律的研究，分析了外磁场作用下铁磁材料的磁化过程与一般规律，同时采用能量分析方法，研究了影响铁磁材料磁畴运动的主要因素，包括应力、掺杂和弥散磁场等，探讨了各种能量对铁磁材料磁行为和磁参量的影响，研究了相应的自发磁化理论和技术磁化理论等。

At first,the as-preparedsample was annealed in an oxidizing atmosphere,the ferromagnetism of the filmdisappeared.

2磁性研究表明：对于不同Tb掺杂量的样品，随Tb掺杂量的增加，样品的每Tb磁矩先增加。

The chapter 3 investigates the constructive method which means that many combinatorial numbers, such as Stirling number, Bell number, harmonic number, Fibonacci number and the number of derangement, are represented to moments of some random variables. This method is used in the computation of combinatorial sums, discovery and proof of combinatorial identities.

第三章研究了构造性概率方法，即一些常见组合变量(以后统称组合数为组合变量)的概率表示，诸如Stirling数、Bell数、调和数、Fibonacci数、错排数都可以表示为一些随机变量的矩，这些概率表示可以用来研究组合和式的计算与恒等式的证明。

For average magnetic moment, average hyperfine field and roomtemperature elastic constants of 〓, the volume effect and the pure substitution effect of Pt atom are seperated by considering the composition dependence of lattice volume.

利用〓晶胞体积随成份的变化，针对平均磁矩、平均超精细场和室温弹性常数，本工作还区分了Pt原子的体积效应和纯粹的替代效应。

Based on the levitation principle of bearingless motor, the torque winding air gap field oriented vector control is utilized to realize the decoupling control of the nonlinear system even in the transient case.

在研究无轴承异步电机的磁悬浮机理的基础上，利用转矩绕组气隙磁场定向控制实现两者之间的动态解耦控制。

The validity of the method is demonstrated by comparison with results obtained from tests on a practical drive system. The influence of damper winding on performances of self-controlled synchronous motor, especially on commutation process and commutation limit, are analyzed in detail. It is shown that damper winding has little effect on increasing overload capability. The influences of field winding on torque, commutation process and overload capability are analyzed also.

然后在此基础上，分析了阻尼绕组和励磁绕组对自控式同步电动机性能的影响，包括对电磁转矩、换流过程和过载能力的影响，重点分析了阻尼绕组对换流过程和换流极限的影响，讨论了阻尼绕组在自控式同步电动机中的作用，得出阻尼绕组对提高过载能力作用不大的看法。

Jacobian, Hessian Matrix Properties, Sensitivity Analysis w.r.t Design Variables, Fixed Parameters and Constraints, Normalization, Finite Difference Approximation, Automatic Differentiation, ANOVA, Adjoint Methods, Examples

Jacobian， Hessian矩阵属性，灵敏度分析w.r.t设计变量，固定参数和约束，归一化，有限差分逼近算法，自动差分算法，ANOVA，伴随矩阵法，举例

Based on the improved first order second moment theory and aimed at the problems of mechanical reliability analysis and mechanical reliability design of single designing variable, this paper put forward a kind of explicit iteration algorithm for computing the structural reliability and determining the designing parameters of structural reliability.

引言改进的一次二阶矩理论是结构可靠性分析和设计的一种实用方法[1]，具有建立结构可靠性分析和设计计算模型简单等优点，在这种方法中，Hasofer和Lind推荐的可靠度指标是定量评估机械可靠性的一种基本参数。

In order to compute the failure probability of structural systems for stability of gravity retaining walls, firstly, two performance functions against overturning and sliding of gravity retaining walls were established. Then, the first order second moment theory in structural reliability analysis, i.e., the checking point method was introduced to compute the two failure modes respectively, and two corresponding reliability indexes could be obtained.

为了计算重力式挡土墙稳定性的结构体系失效概率，首先分别建立重力式挡土墙结构抗倾覆稳定性和抗滑移稳定性的功能函数，然后引入结构可靠度分析一次二阶矩法中的验算点法分别对两种失效模式进行计算，得出两个相应的可靠度指标。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。