Heat and mass transfer in MHD Casson nanofluid flow past a stretching sheet with thermophoresis and Brownian motion

The foremost objective of the current article is to explore the impact of Brownian motion on magnetohydrodynamic Casson nanofluid flow toward a stretching sheet in the attendance of nonlinear thermal radiation. The combined heat and mass transfer characteristics are investigated. The influence of chemical reaction, nonuniform heat source/sink, Soret, and Dufour is deemed. The convective boundary condition is taken. The appropriate transformations are utilized to transform the flow regulating partial differential equations into dimensionless ordinary differential equations (coupled). The numerical outcomes of the converted nonlinear system are solved by the Runge-Kutta based Shooting procedure. Results indicate that the temperature is an increasing function of both thermophoresis and Brownian motion parameters. The concentration of the fluid and the corresponding boundary layer thickness reduces with an enhancement in Lewis number.     

Stationary patterns of a prey–predator system with a protection zone and cross-diffusion of fractional type

This paper is concerned with the stationary patterns of a prey–predator model with a protection zone and fractional type cross-diffusion for the prey. It is shown that the fractional type cross-diffusion has negative effects on the survival of the prey when the intrinsic growth rate of the predator is positive. Moreover, our mathematical analysis shows that, compared with the results obtained in K. Oeda (2011) and K. Oeda (2012), the large cross-diffusion coefficient and large growth rate of the predator species have some essentially different effects on the profiles of the solutions.     

一类带交叉扩散项的捕食-食饵模型的共存态

研究了一类带有交叉扩散项的稀疏效应下捕食-食饵模型在齐次Neumann边界条件下的非常数正解的存在性.首先利用最大值原理和Harnack不等式给出了此模型的正解的先验估计；其次利用积分性质讨论了非常数正解的不存在性；最后利用度理论证明了非常数正解的存在性.     

具有密度依赖扩散的捕食食饵模型的稳定性分析

研究了一类具有非线性扩散的捕食食饵模型,讨论了耦合反应扩散系统平衡态的不稳定性,在有界区域上给出了不稳定的充分条件。结果表明交叉扩散可以导致平衡态的不稳定性。     

一类具有交叉扩散的捕食模型的整体分歧

研究了一类具有交叉扩散的捕食模型在齐次Dirichlet边界条件下正解的存在性.由极大值原理得到正解的先验估计.利用Crandall-Rabinowitz分歧理论,给出局部分歧正解的存在性,并将局部分歧延拓为整体分歧,从而得到正解存在的充分条件.结果表明,捕食者和被捕食者在一定条件下可以共存.     

Insight into the dynamics of micropolar fluid about a vertical cone when nonlinear thermal radiation is significant: The case of triple mixed convection

This novel research investigates the nonlinear triple diffusive combined convective micropolar liquid flow past a vertical cone in the presence of nonlinear thermal radiation, cross-diffusion, and a convective boundary condition. We aim to analyze this present problem using nonsimilar transformations. This report presents the significance of nonlinear mixed convection, energy flux due to the concentration gradient, and mass flux due to the temperature gradient and nonlinear thermal radiation in the dynamics of the fluid subject with micropolar fluid is presented. The differential equations defining the boundary-layer parameters are then transformed into dimensionless view, taking into account the nonsimilar transformation. Furthermore, the method of quasilinearization and implicit finite difference approximation is used to work out the nondimensional governing equations for the solution. The velocity pattern diminishes, while dimensionless temperature and concentration distributions enhance with growing values of microrotation parameter. Furthermore, species concentrations of the fluid increase with increasing Soret effect values, while opposite results appear for mass transfer rates. Also, drag coefficient enhances for assisting buoyancy flow whilst diminishes for opposing buoyancy flow with increasing values of the microrotation parameter. The microrotation pattern reduces with growing values of the nonsimilarity characteristics. Furthermore, the Prandtl number is displayed on a comparison graph, and the results are very similar.     

一类带有交叉扩散项的捕食-食饵模型的分歧

研究了一类带有交叉扩散的捕食-食饵模型在齐次Dirichlet边界条件下正解的存在性.利用极大值原理得到正解的先验估计;通过分析相关特征值问题,得到两条无界的中性曲线;最后以食饵生长率为分歧参数,借助Crandall-Rabinowitz分歧理论,得出局部分歧正解的存在性.     

基于多分数阶混沌系统的彩色图像加密算法

为了实现对彩色图像信息的有效保护,提出一种像素置乱及密文交错扩散技术相结合的加密算法。首先对3个分数阶混沌系统产生的混沌序列进行优化改进,得到两组不同的性能优良的混沌密钥序列,并将RGB彩色图像转换为由基色分量组成的灰度图像;然后,利用一组改进的混沌密钥序列对该灰度图像的像素位置进行置乱;最后,利用另一组改进的混沌密钥序列对置乱图像进行2轮基色分量之间的密文交错扩散操作,得到加密图像。仿真实验表明,该算法具有足够大的密钥空间,高度的密钥敏感性,较好的像素分布特性,且在抵抗唯密文攻击、差分攻击、选择明文攻击及统计攻击方面都具有良好的性能,可以广泛地应用于多媒体数据的保密通信中。     

带有交叉扩散项的捕食-食饵模型的全局分歧

讨论了一类带有交叉扩散项的捕食模型在齐次Dirichlet边界条件下正解的存在性.利用极大值原理得到正解的先验估计;借助Crandall-Rabinowitz分歧理论,得出局部分歧正解的存在性;最后,将局部分歧延拓为全局分歧,得到正解存在的充分条件.从而给出捕食者与食饵在一定条件下可以共存的结果.     

高维空间中竞争-竞争-互惠交错扩散模型的整体解

应用抛物型方程的LP-估计,Shauder理论和Bootstrap技巧,证明了当扩散系数、自扩散系数和交错扩散系数满足一定条件时,竞争-竞争-互惠交错扩散模型在任意维空间中存在古典整体解.