Exact Explicit Peakon and Periodic Cusp Wave Solutions for Several Nonlinear Wave Equations

Using the method of dynamical systems for six nonlinear wave equations, the exact explicit parametric representations of the solitary cusp wave solutions and the periodic cusp wave solutions are given. These parametric representations follow that when travelling systems corresponding to these nonlinear wave equations has a singular straight line, under some parameter conditions, nonanalytic travelling wave solutions must appear. Dedicated to Professor Zhifen Zhang on the occasion of her 80th birthday     

Bifurcations of invariant torus and knotted periodic orbits for the generalized Hopf–Langford system

Nonlinear Dynamics - In this paper, we study the bifurcations of invariant torus and knotted periodic orbits for the generalized Hopf-Langford system. By using bifurcation theory of dynamical...     

An in situ approach to robust superhydrophobic carbon‐based film

In this communication, the novel carbon‐based films have been obtained by a facile in situ deposition method controlling the deposition time, which exhibit a significant increase in the surface hydrophobicity. The detailed cause of this phenomenon has been well probed. The results reveal that the increase of the surface roughness and microstructure modification resulting from the etching effect of F ions could be in charge of the increase of the hydrophobicity. Copyright © 2015 John Wiley & Sons, Ltd.     

微负荷摩擦测试系统

研究了采用浮力原理施力，用高灵敏度应变传感器测力的微负荷摩擦试验方法。测试结果表明，微负荷摩擦测试系统具有较高的分辨率和测试精度。     

磁性流体高压密封能力的计算与试验研究

本文根据磁性流体密封理论对磁性流体高压密封进行了密封能力的计算和试验研究,提出了单级与多级密封能力的计算方法,并且通过磁场的数值计算对密封能力进行了定量分析。所设计的多极-多级密封装置的密封压差可达1.4MPa。文章最后还对计算值与试验值之差异作了分析与探讨。     

Exact Dark Soliton and Its Persistence in the Perturbed2+1-dimensional Davey-Stewartson System

For the Davey-Stewartson system, the exact dark solitary wave solutions, solitary wave solutions, kink wave solution and periodic wave solutions are studied. To guarantee the existence of the above solutions, all parameter conditions are determined. The persistence of dark solitary wave solutions to the perturbed Davey-Stewartson system is proved.     

Wall Effects on Spheres Settling Through Non-Newtonian Fluid Media in Cylindrical Tubes

Experimental study is performed to understand and quantify the wall and eccentric retardation effects on spheres settling in shear thinning and shear-thinning viscoelastic fluids over a wide range of diameter ratios (0.02 < λ < 0.9). The four-parameter Carreau viscosity equation has been chosen to represent the apparent viscosity-shear rate of polyacrylamide solutions. Two new wall factor corrections are presented with excellent agreement compared to experimental data.

The terminal settling velocity of a sphere in bounded fluid is significantly reduced by the presence of confining boundaries, named wall retardation effect that decreases due to the shear-thinning behavior of power law fluids, which is weaken further by the elastic effect of viscoelastic fluids. The wall factors of spheres settling in viscoelastic fluids increase at low ξ up to 50, followed by a horizontal confidence region (0.7 ≤ f ≤ 1) at high ξ. In this region, the wall factor is mainly dominated by fluids’ elasticity, which is more distinguished for small spheres. As the settling spheres approach to the wall (b/R → 1), the neighboring wall exert more intensive retardation that reduce the terminal settling velocity greatly when b/R > 0.6 in pure shear-thinning fluids, and the extra retardation effect of nearby wall increases at high concentration due to the enhanced non-Newtonian property. In contrast, the eccentric effect on settling velocity in viscoelastic fluids is cut down greatly by the fluid's elasticity, which is negligible.     

Ultrasound‐Activated Sensitizers and Applications

Modalities for photo‐triggered anticancer therapy are usually limited by their low penetrative depth. Sonotheranostics especially sonodynamic therapy (SDT), which is different from photodynamic therapy (PDT) by the use of highly penetrating acoustic waves to activate a class of sound‐responsive materials called sonosensitizers, has gained significant interest in recent years. The effect of SDT is closely related to the structural and physicochemical properties of the sonosensitizers, which has led to the development of new sound‐activated materials as sonosensitizers for various biomedical applications. This Review provides a summary and discussion of the types of novel sonosensitizers developed in the last few years and outlines their specific designs and the potential challenges. The applications of sonosensitizers with various functions such as for imaging and drug delivery as well as in combination with other treatment modalities would provide new strategies for disease therapy.