Fusionable and fissionable waves of (2+1)-dimensional shallow water wave equation

We investigate a (2+1)-dimensional shallow water wave equation and describe its nonlinear dynamical behaviors in physics. Based on the N-soliton solutions, the higher-order fissionable and fusionable waves, fissionable or fusionable waves mixed with soliton molecular and breather waves can be obtained by various constraints of special parameters. At the same time, by the long wave limit method, the interaction waves between fissionable or fusionable waves with higher-order lumps are acquired. Combined with the dynamic figures of the waves, the properties of the solution are deeply studied to reveal the physical significance of the waves.     

Isogeometric analysis for time-fractional partial differential equations

Numerical Algorithms - In this paper, we study an inverse source problem for the Helmholtz equation from measurements. The purpose of this paper is to reconstruct the salient features of the hidden...     

基于MgO:QPLN的多光参量振荡器电场调谐特性理论与实验研究

报道了基于掺氧化镁准周期极化铌酸锂(MgO:QPLN)的多光参量振荡器电场调谐特性理论与实验研究. 通过对电场调谐能力与极化结构参数间关联性的理论分析, 确定了高正负晶畴比MgO:QPLN电场调谐的可行性, 并模拟得到跨周期参量光输出波长与加载电压的关系曲线. 实验中通过对MgO:QPLN有效的电场加载, 实现了3.84 μm波段参量光的电场调谐, 频谱调谐带宽约6 nm, 调谐速率接近1 nm/kV, 进一步结合温度调谐, 实现了参量光宽谱段高精度的连续调谐. 所获得实验结果与理论模拟结果基本符合, 电场调谐在精度控制、快速响应方面相比于传统温度调谐更具技术优势.     

基于MgO:APLN的1.57μm/3.84μm连续波内腔多光参量振荡器研究

报道了一种基于MgO:APLN实现1.57 μm和3.84 μm跨周期参量光连续输出的内腔抽运多光参量振荡器. 采用1064 nm谐振腔与多光参量振荡腔折叠型复合结构, 综合考虑高功率抽运下谐振腔的热稳定性及多光参量振荡过程的光斑模式匹配, 通过对两个子腔谐振结构的数值模拟分析, 确定了最佳腔型参数. 在此基础上, 进一步研究了谐振参量光透过率对振荡阈值、抽运光下转换效率、输出功率稳定性的影响, 最终实现了3.13 W的1.57 μm和0.85 W的3.84 μm参量光输出, 对应斜效率为6.8%和1.9%, 输出功率稳定性分别达到了1.8%和3%.     

一阶多参数模糊微分方程及定解问题

在单参数模糊微分方程基础上研究了一阶多参数模糊微分方程和模糊初值问题,利用刻画方程的解与刻画参数的关系给出了多参数模糊微分方程解存在的条件,最后给出了具体算例.表明,多参数模糊微分方程具有广泛的工程应用背景.     

一阶线性模糊微分方程的解

利用文[8]中的扩展原理求解了一阶线性模糊微分方程,给出了解可表示的条件,讨论了同其他求解方法之间的关系,最后给出了具体算例。     

溶剂热法制备银纳米晶

以聚乙烯吡咯烷酮(PVP)作为表面活性剂,利用乙二醇溶剂热法成功制备了银纳米颗粒;利用场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)分析了样品的形貌和晶体结构,并考察了溶剂组成等因素对银纳米颗粒形貌的影响.研究结果表明所得银纳米晶粒径均一,直径约为90nm;增大PVP的加入量会降低产物的粒径,溶剂中水的引入会影响银纳米晶的形貌.     

新三维非线性混沌系统的动力学特性分析

基于动力系统的理论和方法,结合理论分析和Matlab仿真,利用微分方程比较定理和多元函数的Lagrange 乘数法,研究了一类新混沌系统的最终界和全局指数吸引集.对于系统的任意参数,分别得到了该混沌系统最终界和全局吸引集统一的数学表达式.最后,Matlab模拟验证了理论结果的正确性.为该系统的混沌控制、混沌同步、混沌吸引子维数的估计提供了理论依据.     

High brightness and precise adjustment of multicolor-tunable luminescence of Lu2GeO5:Tb3+, Eu3+ phosphors for white LEDs

High brightness and precise adjustment of luminescence colour of phosphors are two main targets in the research of phosphor-converted white LEDs. However, few feasible strategy can be employed to achieve the multicolor-tunable luminescence under the premise of maintaining high quantum efficiency. Here, we demonstrate a high-efficiency energy-transfer process from Tb³⁺ to Eu³⁺ ions with a higher luminescent quantum efficiency (64.5% and 53.4%, respectively), and green-red multicolor emission in Lu₂GeO₅ host via varying the doping content of Tb³⁺ and Eu³⁺ ions. Besides, Lu₂GeO₅:Tb³⁺, Lu₂GeO₅: Eu³⁺ and Lu₂GeO₅: Tb³⁺, Eu³⁺ all exhibit weak thermal quenching which ensures the stable use of white LED device in the high temperature environment. This paper provides a novel multicolor-tunable phosphor with high brightness, efficient energy transfer and weak thermal quenching, which presents a potential application for UV-converted white LEDs.     

一类大气混沌模型的动力学分析及数值仿真

基于已有文献以及微分方程与动力系统的基本理论与方法,采用解析方法推导了一类大气混沌模型的全局吸引域和最终界,并对此模型进行了仿真.数值仿真表明了理论分析结果的正确性.研究结果可为该混沌系统的工程应用和电路设计提供一定的理论依据.