Birkhoff意义下Hénon-Heiles方程的离散变分计算

在Birkhoff意义下研究了非线性不可积Hamilton系统——Hénon-Heiles方程的离散变分计算方法,并和辛算法及Runge-Kutta方法相比较,说明在Birkhoff意义下采用离散变分算法研究非线性不可积系统的动力学行为是合理和可行的. 关键词： Hénon-Heiles方程 离散变分方法 自治Birkhoff方程     

Mobility Enhancement and Gate-Induced-Drain-Leakage Analysis of Strained-SiGe Channel p-MOSFETs with Higher-k LaLuO3 Gate Dielectric

A strained-SiGe p-channel metal-oxide-semiconductor-field-effect transistors （p-MOSFETS） with higher-k LaLu03 gate dielectric was fabricated and electrically characterized. The novel higher-k （k-30） gate dielectric, LaLuO3, was deposited by molecular-beam deposition and shows good quality for integration into the transistor. The transistor features good output and transfer characteristics. The hole mobility was extracted by the splitting C-V method and a value of 2OOcm2/V.s was obtained for strong inversion conditions, which indicates that the hole mobility is well enhanced by SiGe channel and that the LaLuO3 layer does not induce additional significant carrier scattering. Gate induced drain leakage is measured and analyzed by using an analytical model. Band-to- band tunneling et~ciencies under high and low fields are found to be different, and the tunneling mechanism is discussed.     

220 GHz三次谐波光子带隙谐振腔回旋管振荡器的研究

提出了一种220 GHz三次谐波光子带隙谐振腔回旋管振荡器的物理结构.利用光子晶体高频带隙确定了回旋管高阶电磁模式类TE63和三次电子回旋模的互作用状态.通过非线性理论,研究了腔内类TE63和类TE92模的弱模式竞争,得到了有利于回旋管三次谐波起振的工作条件和起振过程的非线性特征,其结果与粒子模拟基本一致.研究表明,利用光子带隙谐振腔的禁带特征,回旋管中高阶电磁模与高次电子回旋模能够发生有效的互作用关系被得到证实.     

多结级联垂直腔面发射激光器失效分析

对自主研发的940 nm大功率三结垂直腔面发射激光器(VCSEL)单点器件的高温高电流老化失效后的器件进行了失效分析研究.首先,通过热阻测试确定了加速老化实验的结温,并计算了老化加速因子为104.随后,对老化过程中产生的失效器件进行失效分析.通过老化前后器件L-I-V、正反向V-I、光学及红外外观、近场光斑及透射电子显...     

Stability analysis of a simple rheonomic nonholonomic constrained system

It is a difficult problem to study the stability of the rheonomic and nonholonomic mechanical systems. Especially it is difficult to construct the Lyapunov function directly from the differential equation. But the gradient system is exactly suitable to study the stability of a dynamical system with the aid of the Lyapunov function. The stability of the solution for a simple rheonomic nonholonomic constrained system is studied in this paper. Firstly, the differential equations of motion of the system are established. Secondly, a problem in which the generalized forces are exerted on the system such that the solution is stable is proposed. Finally, the stable solutions of the rheonomic nonholonomic system can be constructed by using the gradient systems.     

自缩短效应对Kerr被动锁模激光器稳定区的影响

利用谐振腔的往返矩阵理论以及谐振腔的稳定性条件研究了锁模激光器的稳定区与激光腔内光功率的关系,从而得出在高脉冲功率下自缩短效应对Kerr被动锁模飞秒激光器的稳定区的影响.利用激光谐振腔的此性质可以对Kerr被动锁模激光器的谐振腔的设计进行优化,从而提高其锁模的可实现性以及谐振腔的稳定性.     

碱土金属对钴铈复合氧化物催化剂催化N2O分解的影响

采用低温柠檬酸络合法制备了添加不同碱土金属的钴铈复合氧化物(Ce/Co摩尔比为0.05)催化剂, 考察了其催化N2O分解的活性. 结果表明, 碱土金属对钴铈催化剂催化N2O分解的活性有明显促进作用, 助催化效果递变顺序为Mg相似文献   

碱土金属对钴铈复合氧化物催化剂催化N2O分解的影响

采用低温柠檬酸络合法制备了添加不同碱土金属的钴铈复合氧化物(Ce/Co摩尔比为0.05)催化剂,考察了其催化N2O分解的活性.结果表明,碱土金属对钴铈催化剂催化N2O分解的活性有明显促进作用,助催化效果递变顺序为Mg相似文献   

Decomposition of almost-Poisson structure of generalised Chaplygin’s nonholonomic systems

This paper constructs an almost-Poisson structure for the non-self-adjoint dynamical systems, which can be decomposed into a sum of a Poisson bracket and the other almost-Poisson bracket. The necessary and sufficient condition for the decomposition of the almost-Poisson bracket to be two Poisson ones is obtained. As an application, the almost-Poisson structure for generalised Chaplygin's systems is discussed in the framework of the decomposition theory. It proves that the almost-Poisson bracket for the systems can be decomposed into the sum of a canonical Poisson bracket and another two noncanonical Poisson brackets in some special cases, which is useful for integrating the equations of motion.     

高机械性能的聚(丙烯酸-co-甲基丙烯酸十八酯)疏水缔合凝胶的溶胀行为研究

以丙烯酸(AA)、甲基丙烯酸十八酯(OMA)、十二烷基硫酸钠(SDS)为原料,采用胶束共聚的方法合成了疏水缔合(HA)凝胶.在HA凝胶内部,表面活性剂SDS与疏水单体OMA组成的增溶胶束起到物理交联作用,将亲水的聚合物链交联起来.通过单向拉伸试验证实了该凝胶具有较高的机械性能.此外,也测试了HA凝胶在不同pH值溶液中的溶胀行为.结果显示,HA凝胶具有特殊的溶胀行为,其溶胀过程可以分为凝胶溶蚀、溶胀平衡和凝胶瓦解3个阶段.在强酸性条件下,凝胶的溶胀被抑制,没有出现凝胶瓦解阶段.在强碱性条件下,凝胶的溶胀被促进,溶胀平衡阶段被越过.盐的存在也会抑制HA凝胶的溶胀,但在SDS溶液中,溶液中的SDS会促使凝胶中的疏水改性聚合物溶解到溶液中去,组成新的缔合结构,而使溶液增稠。