In this work, we analyze a one-dimensional steady-state Poisson--Nernst--Planck-type model for ionic flow through membrane channel with fixed boundary ion concentrations (charges) and electric potentials. We consider two species, one positively charged negatively charged, assume zero permanent charge. A local hard-sphere potential that depends pointwise on is included in the to account size effects flow. The problem treated as value of singularly perturbed differential system. Our analysis...

Analytical and numerical investigations into the dynamics control of dive-plane supercavitating vehicles are presented. Dominant nonlinearities associated with planing forces taken account in model. Two controllers proposed to realize stable inner-loop dynamics, a linear state feedback scheme switching scheme. Through simulations estimation region attraction, it is shown that effective schemes can be constructed. In comparison existing schemes, this work stabilize vehicle large attraction...

In this effort, a numerical study of the bifurcation behavior supercavitating vehicle is conducted. The model nonsmooth; result planing force acting on vehicle. With focus dive-plane dynamics, bifurcations with respect to quasi-static variation cavitation number are studied. system found exhibit rich and complex nonlinear dynamics including nonsmooth such as grazing bifurcation; smooth Hopf bifurcations, cyclic fold period-doubling bifurcations; aperiodic behaviors transient chaotic motions...

We provide a detailed study for ionic flow through ion channels the case with three species, two positively charged having same valence and one negatively charged, zero permanent charge. The work is based on general geometric theory developed in [W. Liu, J. Differential Equations, 246 (2009), pp. 428--451] quasi-one-dimensional steady-state Poisson--Nernst--Planck model. Our focus effects of boundary conditions flow. Beyond existence solutions model problem, we are able to obtain explicit...

As an important part of the quadruped robot, leg determines its performance. Flexible legs or flexible joints aid in buffering and adaptability robots. At present, most robots only have two-dimensional flexibility use complex parallel structures to achieve three-dimensional flexibility. This research will propose a new type structure. passive compliant reduces weight structure robot. The anti-impact performance robot is verified by side impact experiment. simulation experiments show that...

An unknown nonlinear disturbance seriously affects the trajectory tracking of autonomous underwater vehicles (AUVs). Thus, it is critical to eliminate influence such disturbances on AUVs. To address this problem, paper proposes a double-loop proportional–integral–differential (PID) neural network sliding mode control (DLNNSMC). First, PID surface proposed, which has faster convergence speed than other surfaces. Second, high-order observer and are combined observe compensate for AUV system....

The focus of this work is on the complicated nonlinear interaction between a supercavitating vehicle and surrounding fully developed cavity. Dominant nonlinearities associated with planing forces are taken into account in model, fixed points limit cycles dynamics studied. Through analysis, tail-slap phenomenon vehicles interpreted as cycle motion. qualitative analysis serves basis for stabilizing feedback control designs. Several inner-loop designs, which include switching backstepping...

Absolute stability is considered under an asymmetric sector condition, resulting in a generalization of the classical absolute analysis. In addition to extension conditions, current approach, based on recent work Leonov (2005), yields results that are both necessary and sufficient for stability. An condition allows different bounds be imposed regions state space, removes restriction system nonlinearity confined only first third quadrants. This applies second-order systems. The conditions...

In this paper, a soft robot driven by gas–liquid phase transition actuator with new structure is designed; The the pressure generated electrically induced ethanol transition. drive was found to be able generate larger driving force using only low voltage. Compared gas of traditional robot, transition-driven does not require complex circuit system and huge external energy supply air pump, making its overall more compact. At same time, because on has good tightness less recovery time. A...

Analytical and numerical investigations conducted into the control of dive-plane dynamics supercavitating bodies are presented. Particular attention is paid to tail-slap behavior. A fundamental understanding solution structure in terms equilibrium other solutions developed through effort discussed, schemes used realize stable inner loop Dominant nonlinearities associated with planning forces taken account model controllability system fin input and/or cavitator has been examined. The...

Numerical investigations conducted into the dive-plane dynamics of supercavitating bodies, which are described by a non-smooth system, discussed. For selected set system-parameter values, fundamental understanding solution structure obtained in terms equilibrium and periodic solutions is presented. After carrying out smoothing approximations, bifurcations resulting smooth system studied using cavitation number as control parameter. Supercritical Hopf fixed points period-doubling found, use...

Abstract Under the assumptions that spatial variable is one dimensional and distributed delay kernel general Gamma kernel, when average small, existence of travelling wave solutions for population genetics model with obtained by using linear chain trick geometric singular perturbation theory. On other hand, small discrete delay, employing a technique which based on result concerning inertial manifold equations.

In this effort, a numerical study of the bifurcation behavior supercavitating vehicle is conducted. The nonsmoothness system due to planing force acting on vehicle. With focus dive-plane dynamics, bifurcations with respect quasi-static variation cavitation number are studied. found exhibit rich and complex dynamics including nonsmooth such as grazing smooth Hopf bifurcations, cyclic-fold period-doubling chaotic attractors, transient motions, crises. tailslap phenomenon identified consequence...

This study aims to achieve synergistic strength-ductility enhancement of semi-solid squeeze cast 6TiB2/Al–17Si–4Cu composites through in-situ particle strengthening and T6 heat treatment. The microstructure mechanical properties with different treatments were investigated. TiB2 particles are semi-coherent α-Al primary Si, respectively. nanoscale precipitate phases determined by their crystal orientation relationships. results showed that they θ θʹ phases. Meanwhile, the research pertaining...

A general theorem about the existence of periodic solutions for equations with distributed delays is obtained by using linear chain trick and geometric singular perturbation theory. Two examples are given to illustrate application therom.