单阶

The nonlinear absorption and nonlinear refractive index of porous silicon/DR1 composite films at 1064nm have been measured respectively.

用单光束扫描法研究了多孔硅／DR1复合膜的三阶非线性光学性质，测量了在1064nm处多孔硅／DR1复合膜的双光子吸收系数和非线性折射率。

Based on the original research of the high order single step method ,this paper makes the research on the applicability of this method for the analytic expression of stiffness.

本文在原有高阶单步法研究的基础上对刚度为时间解析函数时方法的适用性进行了研究。

As applications, the 2nd elastic moduli are used to explain the effect of chiral angle on asymmetry behavior of torsion, and finite deformation problems of single-walled carbon nanotubes are successfully simulated by the thin shell model.

作为应用：利用面内的2阶模量解释了纳米管螺旋角相关的力学行为：扭转不对称现象。利用薄壳模型成功模拟了单壁纳米管的大变形弹性失稳行为。

The dissertation focuses on performance gradient estimation and SRO algorithm of DES aswell as other related topics,such as modeling of DES and discrete event simulation,performancemeasure Hessian matrix estimation,Stochastic Approximationand so on.General Semi-Markov Processis adapted to describe behaviour of DES and discrete eventsimulation.A general result is obtained and applied to analyze strong consistency of performancegradient Perturbation Analysisestimator.Conditions for effectiveness of InfinitesimalPerturbation Analysisare also discussed.New PA algorithms,such as server PA,PA usingDirac generalized function,job sequence PA etc.,are proposed to deal with discreteparameters.Furthermore,strategies of combining PA algorithms with certain iterative rules areanalyzed widely in order to optimize DES parameters and some SRO algorithms are constructed toslove DES optimization problems.

论文将DES性能分析领域中性能梯度估计和单运行仿真优化作为主要的研究对象，探讨了与性能梯度估计有关的DES和离散事件仿真过程建模、高阶导数估计以及随机逼近等理论和方法；建立了具有一般性的DES和离散事件仿真的广义半Markov过程模型；获得了分析性能梯度估计量强相合性的理论结果和无穷小摄动分析算法应用的条件；提出了诸如服务台数目的摄动分析、奇异摄动分析、串联生产线和加工车间中工件加工序的摄动分析等一系列摄动的思想和算法，对连续参数和离散参数都进行了深入的研究；对摄动分析算法同优化规则结合实现仿真优化的策略也进行了广泛的分析，构造了新型的变界截尾的随机逼近算法，并用于DES的单运行仿真优化研究；最后，给出了DES性能分析方法的实证性研究结果。

In chapter 6, we discussed the wavefront solution of a kind of lattice differential equation which derives from diverse fields. We obtained the wavefront solution by using sup-subsolution iteration when the coupled functions are quasimonotone, and by applying Schauder fixed point theorem, we also obtained the wavefront solution when the coupled functions have a different quasimonotone property.

在第六章中，我们对一类从实际问题中抽象出来的二阶时滞格微分方程的行波解进行了讨论，用单调迭代的方法讨论了耦合函数具有拟单调性时行波解的存在性，用不动点的方法讨论了耦合函数具有指数拟单调性时行波解的存在性。

This paper makes use of PID control, Fuzzy- PID control based on single parameter these two control strategies to simulate the systems model. Compared with common vehicle, the results of simulation show that the vehicle equipped with the electromagnetic power steering system has better yaw velocity frequency response characteristic under condition with step input of steering wheel, so it has more betterhandling stability; Compared with PID control strategy, the results show that the Fuzzy-PID control strategy has the advantages, such as response fast, stabilize itself quickly and less over-altitude.

本文使用了PID、单参数自整定Fuzzy-PID两种控制策略对系统模型进行控制，仿真结果表明：相对于普通汽车，装有电磁式助力转向系统的汽车在方向盘转角阶跃输入的情况下，汽车横摆角速度频率响应特性更好，因此具有更好的操纵稳定性；而相对于采用PID控制，采用单参数自整定Fuzzy-PID控制又可以使系统响应更迅速、超调量更小、稳定更快。

Chirp scaling algorithm is considered more efficient and widely applicable when the bistatic SAR system is in side-look or small squint angle mode,but in large squint angle case,the errors caused by Taylor expansion are so large that the algorithm could lose its precision.In such a case,an equivalent mono-static SAR range mode which has fewer errors than Taylor expansion with large squint angle is proposed to substitute the range history of bistatic SAR.Then bistatic SAR images with large squint angles are gotten by common Nonlinear CS algorithm.The effectivity of the method is verified by Matlab simulation.

在正侧视或小斜视情况下，CS算法具有较好的聚焦性能和广泛的适用性，但在斜视角较大的情况下，该算法将散焦而不能成像，因而提出了用等效的单基地距离模型来代替双基地距离历史的方法，解决了大斜视角情况下距离模型二阶近似误差较大的问题，并结合单基地非线性CS算法，实现了在大斜视角情况下的基于GPS反射信号的双基地SAR高精度成像，最后通过Matlab仿真进行了验证。

a system of along-track mode sar based on the gps is established.by seeing the gps signal as a chirp,chirp scaling algorithm of this mode with large squint angle is investigated.chirp scaling algorithm is considered more efficient and widely applicable when the bistatic sar system is in side-look or small squint angle mode,but in large squint angle case,the errors caused by taylor expansion are so large that the algorithm could lose its precision.in such a case,an equivalent mono-static sar range mode which has fewer errors than taylor expansion with large squint angle is proposed to substitute the range history of bistatic sar.then bistatic sar images with large squint angles are gotten by common nonlinear cs algorithm.the effectivity of the method is verified by matlab simulation.

摘 要：建立了基于gps的顺轨sar系统模型，通过将gps信号等效为chirp信号，研究了在该模式下的大斜视角chirp scaling算法。在正侧视或小斜视情况下，cs算法具有较好的聚焦性能和广泛的适用性，但在斜视角较大的情况下，该算法将散焦而不能成像，因而提出了用等效的单基地距离模型来代替双基地距离历史的方法，解决了大斜视角情况下距离模型二阶近似误差较大的问题，并结合单基地非线性cs算法，实现了在大斜视角情况下的基于gps反射信号的双基地sar高精度成像，最后通过matlab仿真进行了验证。

In this paper the equations of the stability and shear, flexural vibration of the straight bars with varying cross-section and the equations of motion of one degree of freedom systems with varying parameters are written as a unified self-adjoint differential equation of the second order eq.

本文将变截面杆的稳定与剪切、弯曲振动方程，以及具有变参数的单自由度体系的振动方程等均化为统一的二阶自共轭微分方程：并对，且的情形，将二阶自共轭方程化为贝塞尔方程。

The intermittent chaos and subharmonics in high-order switching power converters are studied with a current-mode controlled SEPIC (single ended primary inductor converter) converter serving as an example.

以四阶电流模式控制单端初级电感变换器(single ended primary inductor converter，SEPIC)为例，研究高阶开关功率变换器中的间歇混沌和间歇分谐波现象。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷