Existence and uniqueness of steady state solutions of a nonlocal diffusive logistic equation

In this paper, we consider a dynamical model of population biology which is of the classical Fisher type, but the competition interaction between individuals is nonlocal. The existence, uniqueness, and stability of the steady state solution of the nonlocal problem on a bounded interval with homogeneous Dirichlet boundary conditions are studied.     

总体协差阵为单位阵的最小距离判别

本引进最小距离域定义,得到了确定最小距离域的计算方法。在马氏距离判别定理的基础上,确定了最小距离判别规则,得到了利用该规则的判别方法。     

Periodic solutions of a logistic type population model with harvesting

We consider a bifurcation problem arising from population biology

     

非单特征值的广义分歧定理

讨论了抽象算子方程F(λ,u)=0的局部分歧问题,其中F:R×X→Y是一个C2微分映射,λ是参数,X,Y为Banach空间.利用Lyapunov-Schmidt约化过程及偏导算子Fu(λ*,0)的有界线性广义逆,在dim N(Fu(λ*,0))≥codim R(Fu(λ*,0))=1的条件下,证明了一个广义跨越式分歧定理.当参数空间的维数等于值域余维数时,应用同样的方法又得到了多参数方程的抽象分歧定理.     

An investigation of molecular layering at the liquid-solid interface in nanofluids by molecular dynamics simulation

The molecular layering at liquid-solid interface in a nanofluid is investigated by equilibrium molecular dynamics simulation. By tracking the positions of the nanoparticle and the liquid atoms around the spherical nanoparticle, it was found that an absorbed slip layer of liquid is formed at the interface between the nanoparticle and liquid; this thin layer will move with the Brownian motion of the nanoparticle. Through the analysis of the density distribution of the liquid near the nanoparticle it is found that the thickness of the layering is about 0.5 nm under the parameters used in the Letter.     

The research in image distinction for isodyne patterns

A new birefringent phase shift method applied in isodyne fringe pattern distinction is developed. The phase map obtained by the new method corresponds to the isodyne surface in whole fields. The theory and technique of the new method is described and a bimaterial beam under three-point bending is studied as an example.     

可调实时时间差电子错位散斑技术及应用

本文首次提出一种可调实时时间差电子错位散斑干涉技术,并成功地用于热变形测量,该方法还可用于长时间连续变形和瞬态大变形的位移测量。叙述了该技术的原理,给出了一些应用的实验结果。     

激光诱导AZ31B镁合金薄板动态响应实验研究

为分析在激光冲击波作用下AZ31B镁合金薄板背面的动态响应,采用聚偏氟乙烯贴片传感器与数字示波器对强激光诱导的冲击波进行测量,得到压电波形,结合冲击波的传播特性,对弹塑性双波的传播规律进行了研究。结果表明：激光诱导的材料动态响应是快速的;压电波形图反映出的弹性前驱波与塑性加载波传播到靶材背面的时间与理论时间相符;弹性前驱波能量小引发的波形振幅较小,紧随着的塑性加载波能量大并引起较大振幅波动,弹塑性双波卸载过程与紧接着的加载过程导致了压电信号的波动振幅提高。     

光源加热型高灵敏度光纤热式风速计

卫星钟差确定受限于经典测量的散粒噪声极限,钟差测量精度仅为ns量级。基于军民领域对高精度时间基准的迫切需求,提出了一种基于双路六延迟传送带量子纠缠光的卫星钟差测量方案,并且该方案以传送带协议为基础。首先,通过自发参量下转换制备了频率纠缠光信号。然后,利用HOM (Hong-Ou-Mandel)干涉仪对频率纠缠光信号进行了二阶关联检测解算,进而得到了钟差信息。最后,仿真分析了相关参数对钟差测量的影响。所提方案无需进行到达时间测量,不受色散效应及星地距离的影响,在理论上可以实现ps量级的卫星钟差测量。     

Effects of large blood vessels on the transient propagation of ultrafast laser pulse in biological tissues

A typical vascular model is established to study the effects of large blood vessels on the transient laser propagation during optical imaging. A time-resolved Monte Carlo algorithm is developed to investigate transient light propagation in biological tissues with embedded tumors and blood vessels. The results indicate that inclusion of the vasculatures could significantly alter light propagation transients from those obtained from the tissue embedded with tumor only.