高维非齐次时间分数阶扩散-波动方程的解析解问题

分数阶微积分是专门研究任意阶积分和微分的数学性质及其应用的领域,是传统的整数阶微积分的推广,分数阶微分方程是含有非整数阶导数的方程.时间分数阶扩散-波动方程可以用来模拟由传统的扩散-波动方程演变而来的反常扩散方程.考虑在有限区间上高维非齐次时间分数阶扩散-波动方程的初边值问题.利用分离变量法,导出了高维非齐次时间分数阶扩散-波动方程初边值问题的基本解.     

输油管道的布置

本文建立了非线性规划模型,解决了输油管线布置问题,并给出了输油管线铺设的最佳方案.     

Investigation on the scattering effect of ceramic Nd:YAG

This paper investigates the scattering effect of domestic 0.5 at{\%} ceramic Nd:YAG. An effective method has been utilized to measure the scattering and absorption coefficients. An end-pumped continuous wave (CW) Nd:YAG ceramic laser was also demonstrated. A maximum output power of 6.7~W at 1064~nm was obtained at an 808-nm pump power of 32.9~W. Conversion efficiency and slope efficiency have been achieved. This indicates that scattering has an important effect on the optical performance of ceramic Nd:YAG.     

物理隔离网络电磁漏洞研究

物理隔离网络的电磁攻击手段, 其主要目标是建立与外部互联网的隐蔽连接通道。近年来跨越物理隔离网络的方法和工具被陆续公开, 相应的分析方法和检测手段也逐步被国内外安全团队提出。掌握漏洞才能掌握网络安全的主动权, 对比网络安全漏洞, 电磁漏洞定义为能对设备或系统造成损害的电磁因素。以物理隔离网络为例, 电磁漏洞主要指的是网络的硬件和系统缺陷, 利用这些缺陷可以直接建立或通过植入恶意软件建立能突破物理隔离的电磁信号的信息收、发隐蔽通道。通过广泛的漏洞挖掘与验证, 从物理信号类型、信息传递方向、信号生成与作用机理、漏洞利用方式以及漏洞检测方法上提出物理隔离网络电磁漏洞分类方法; 通过综合借鉴网络安全漏洞、电磁信息安全检测、物理隔离隐蔽通道等领域的研究方法, 提出电磁漏洞的研究方法; 从深化主动检测、群智漏洞挖掘、网络电磁安全融合、大数据监测等角度, 提出了物理隔离网络电磁漏洞库的建立方法。     

12 W high power InGaAsP/AlGaInP 755 nm quantum well laser

High power laser diodes(LDs) with a lasing wavelength between 700 and 780 nm have great potential in various medical uses. Here, we report our recent efforts in developing an InGaAsP/AlGaInP-based commercial high power edge-emitting LD, which has 755 nm emission peak with a world-record continuous wave output power of 12.7 W, the highest reported so far. The lack of Al atoms in the active region significantly lowers the chance of catastrophic optical damage during high power laser operation. Meanwhile, with an accumulated 3800 h running time, our ongoing aging tests reveal excellent reliability of our devices.     

Ejecta from periodic grooved Sn surface under unsupported shocks

Dynamic failure and ejection characteristics of a periodic grooved Sn surface under unsupported shock loading are studied using a smoothed particle hydrodynamics method. An "Eiffel Tower" spatial structure is observed, which is composed of high-speed jet tip, high-density jet slug, longitudinal tensile sparse zone, and complex broken zone between grooves. It is very different from the spike-bubble structure under supported shocks, and has been validated by detonation loading experiments. In comparison with that under supported shocks at the same peak pressure, the high-speed ejecta decreases obviously, whereas the truncated location of ejecta moves towards the interior of the sample and the total mass of ejecta increases due to the vast existence of low-speed broken materials. The shock wave profile determines mainly the total ejection amount, while the variation of V-groove angle will significantly alter the distribution of middle-and high-speed ejecta, and the maximum ejecta velocity has a linear correlation with the groove angle.     

一种统一的Fuzzy化方法和代数系的Fuzzy化

§1 引言各种分明集的Fuzzy化是Fuzzy集理论基本手法之一。目前较流行的孤立的定义方法没有很好地体现出Fuzzy化是一个统一的概念。本文探讨了“拼Fuzzy集”[1]与其分明集的关系及它们在隶属函数形式上的一致性问题,从而给出了一种统一的Fuzzy化方法。     

一类p-Laplace方程边值问题解的存在性

主要讨论一维p-Laplace方程在Neumann边值条件u(0)=0,u(1)=0下,对应的边值问题解的存在性.通过使用度理论,在适当的条件下,建立了对于p-Laplace方程在Neumann条件下解的存在性的充分条件.     

广义逆与Lax定理的推广

Lax定理是泛函分析中的一个重要结果。它在偏微分方程中有重要应用,它可表述如下: 若V是一个实的Hilbert空间,α(u,v)为V×V上的连续双线性泛函,且存在C>0使     

一类三阶微分方程边值问题的单调迭代法

用单调迭代法研究一类三阶微分方程边值问题解的存在性,不仅证明了该问题解的存在性,而且得到了其迭代格式.