Transient Response and Ionic Dynamics in Organic Electrochemical Transistors

The rapid development of organic electrochemical transistors(OECTs)has ushered in a new era in organic electronics,distinguishing itself through its application in a variety of domains,from high-speed logic circuits to sensitive biosensors,and neuromorphic devices like artificial synapses and organic electrochemical random-access memories.Despite recent strides in enhancing OECT performance,driven by the demand for superior transient response capabilities,a comprehensive understanding of the complex interplay between charge and ion transport,alongside electron–ion interactions,as well as the optimization strategies,remains elusive.This review aims to bridge this gap by providing a systematic overview on the fundamental working principles of OECT transient responses,emphasizing advancements in device physics and optimization approaches.We review the critical aspect of transient ion dynamics in both volatile and non-volatile applications,as well as the impact of materials,morphology,device structure strategies on optimizing transient responses.This paper not only offers a detailed overview of the current state of the art,but also identifies promising avenues for future research,aiming to drive future performance advancements in diversified applications.

Research on Transient Response of Motorcycle with One Tire Colliding on Ground

Aim To study the transient response of motorcycle with one tire colliding on ground. Methods Taking the colliding velocity as an independent variable, the changing law of the biggest collision inertia load of motorcycle′s sprung mass, unsprung mass and driver was studied, while its front and rear tire colliding on ground respectively.Results and Conclusion According to the working conditions of motorcycle shock absorbers and the characteristic of response curve, the transient response of the acceleration, the velocity and the displacement were discussed section by section. And the result of simulating the actual JH125 motorcycle was given.

Transient response of a spherical cavity with a partially sealed shell embedded in viscoelastic saturated soil

Based on Biot’s wave equation, this paper discusses the transient response of a spherical cavity with a partially sealed shell embedded in viscoelastic saturated soil. The analytical solution is derived for the transient response to an axisymmetric surface load and fluid pressure in Laplace transform domain. Numerical results are obtained by inverting the Laplace transform presented by Durbin, and are used to analyze the influences of the partial permeable property of boundary and relative rigidity of shell and soil on the transient response of the spherical cavity. It is shown that the influence of these two parameters is remarkable. The available solutions of permeable and impermeable boundary without shell are only two extreme cases of this paper.

Effect of the Transient Response in Si/Ge Parallelizing PN Junction

There are some new results about photovoltaic transient response in the new effect. We suggest a theoretical model to explain the effect reasonably. The theoretical calculation results agree with that in experiments.

TRANSIENT RESPONSE OF A VALVE CONTROL HYDRAULIC SYSTEM WITHLONG PIPES

The simulation model of a valve control hydraulic system with long pipe isestablished in Simulink4.0, and then the step responses of the systems with difference pipeparameters are investigated by simulation. Simulation results show that the long pipes will slowdown the step response of system and make it fluctuate periodically. The results of simulationconform to the results of experiment on the whole, which proves the mathematic model is correct.

Influence of porosity distribution on nonlinear free vibration and transient responses of porous functionally graded skew plates

This article deals with the investigation of the effects of porosity distributions on nonlinear free vibration and transient analysis of porous functionally graded skew(PFGS)plates.The effective material properties of the PFGS plates are obtained from the modified power-law equations in which gradation varies through the thickness of the PFGS plate.A nonlinear finite element(FE)formulation for the overall PFGS plate is derived by adopting first-order shear deformation theory(FSDT)in conjunction with von Karman’s nonlinear strain displacement relations.The governing equations of the PFGS plate are derived using the principle of virtual work.The direct iterative method and Newmark’s integration technique are espoused to solve nonlinear mathematical relations.The influences of the porosity distributions and porosity parameter indices on the nonlinear frequency responses of the PFGS plate for different skew angles are studied in various parameters.The effects of volume fraction grading index and skew angle on the plate’s nonlinear dynamic responses for various porosity distributions are illustrated in detail.

Transient Hydroelastic Response of VLFS by FEM with Impedance Boundary Conditions in Time Domain

A time-dependent finite element method (FEM) is developed to analyze the transient hydroelastic responses of very large floating structures (VLFS) subjected to dynamic loads. The hydrodynamic problem is formulated based on the linear theory of fluid and the structural response is analyzed based on the thin plate theory. The FEM truncates the unbounded fluid domain by introducing an artificial boundary surface, thus defining a finite computational domain. At this boundary surface an impedance boundary conditions are applied so that no wave reflections occur. In the proposed scheme, all of the procedures are processed directly in time domain, which is efficient for nonlinear analyses of structure floating on unbounded fluid. Numerical results indicate acceptable accuracy of the proposed method.

Exact solutions to one-dimensional transient response of incompressible fluid-saturated single-layer porous media

Based on the Biot theory of porous media, the exact solutions to one- dimensional transient response of incompressible saturated single-layer porous media un- der four types of boundary conditions are developed. In the procedure, a relation between the solid displacement u and the relative displacement ＇w is derived, and the well-posed initial conditions and boundary conditions are proposed. The derivation of the solution for one type of boundary condition is then illustrated in detail. The exact solutions for the other three types of boundary conditions are given directly. The propagation of the compressional wave is investigated through numerical examples. It is verified that only one type of compressional wave exists in the incompressible saturated porous media.

Transient Response Model of Standing Wave Piezoelectric Linear Ultrasonic Motor

A transient response model for describing the starting and stopping characteristics of the standing wave piezoelectric linear ultrasonic motor was presented. Based on the contact dynamic model, the kinetic equation of the motor was derived. The starting and stopping characteristics of the standing wave piezoelectric linear ultrasonic motor according to different loads, contact stiffness and inertia mass were described and analyzed, respectively. To validate the transient response model, a standing wave piezoelectric linear ultrasonic motor based on in-plane modes was used to carry out the simulation and experimental study. The corresponding results showed that the simulation of the motor performances based on the proposed model agreed well with the experimental results. This model will helpful to improve the stepping characteristics and the control flexibility of the standing wave piezoelectric linear ultrasonic motor.

Approximate analytical solutions and experimental analysis for transient response of constrained damping cantilever beam

Vibration mode of the constrained damping cantilever is built up according to the mode superposition of the elastic cantilever beam. The control equation of the constrained damping cantilever beam is then derived using Lagrange＇s equation. Dynamic response of the constrained damping cantilever beam is obtained according to the principle of virtual work, when the concentrated force is suddenly unloaded. Frequencies and transient response of a series of constrained damping cantilever beams are calculated and tested. Influence of parameters of the damping layer on the response time is analyzed. Analyitcal and experimental approaches are used for verification. The results show that the method is reliable.

NONLINEAR TRANSIENT RESPONSE OF STAY CABLE WITH VISCOELASTICITY DAMPER IN CABLE-STAYED BRIDGE

Taking the bending stiffness, static sag, and geometric non-linearity into consideration, the space nonlinear vibration partial differential equations were derived. The partical differential equations were discretized in space by finite center difference approximation, then the nonlinear ordinal differential equations were obtained. A hybrid method involving the combination of the Newmark method and the pseudo-force strategy was proposed to analyze the nonlinear transient response of the inclined cable-dampers system subjected to arbitrary dynamic loading. As an example, two typical stay cables were calculated by the present method. The results reveal both the validity and the deficiency of the viscoelasticity damper for vibration control of stay cables. The efficiency and accuracy of the proposed method is also verified by comparing the results with those obtained by using Runge-Kutta direct integration technique. A new time history analysis method is provided for the research on the stay cable vibration control.

Transient impact responses of laminated composite cylindrical shells

The generalized ray method(GRM) has been successfully used to study the transient elastic wave transmitting in the beams,planar trusses,space frames and infinite layered media.In this letter,the GRM is extended to investigate the early short time transient responses of laminated composite cylindrical shells under impact load.By using the Laplace transformation and referring to the boundary conditions,the ray groups transmitting in the finite laminated cylindrical shells under the shock load are obtained and the transient response related to each ray group can be derived via FFT algorithm.From the numerical results,it is shown that the early short time transient accelerations of the laminated composite cylindrical shell under impact loads are very large.But the short time transient shear strain and displacement are very small.

TRANSIENT RESPONSE INVESTIGATION OF GIMBALLED TILTROTORS DURING ENGAGE AND DISENGAGE OPERATIONS

An analysis has been developed to predict the transient aeroelastic response of gimballed tiltrotors during shipboard engage/disengage operations. A multi blade gimballed rotor is modeled with slender elastic beams rigidly attached to a hub and undergoing flap bending, lag bending, elastic twist, and axial deflection. The gimbal restraint is simulated using a conditional rotational spring. Blade element theory is used to calculate quasi steady loads in linear and nonlinear regimes. The rotor equations of motion are formulated using Hamiltons principle and spatially discretized using the finite element method. The discretized rotor equations of motion are integrated in the modal space for a specified rotor speed run up profile. Studies for a 1/5 size aeroelastically scaled tiltrotor model are conducted to validate the analysis and investigate the transient response and loads of the gimballed rotor during engagement. Blade bending moment and hub moment predictions indicated that gimbal restraint impacts can induce high transient loads on the rotor blades and hub.

A convolution-type semi-analytic DQ approach to transient response of rectangular plates

The convolution-type Gurtin variational principle is known as the only variational principle that is, from the mathematics point of view, totally equivalent to the initial value problem system. In this paper, the equation of motion of rectangular thin plates is first transformed to a new governing equation containing initial conditions by using a convolution method. A convolution-type semi-analytical DQ approach, which involves differential quadrature （DQ） approximation in the space domain and an analytical series expansion in the time domain, is proposed to obtain the transient response solution. This approach offers the same advantages as the Gurtin variational principle and, at the same time, is much simpler in calculation. Numerical results show that it is very accurate yet computationally efficient for the dynamic response of plates.

Transient Responses of Flexible Non-uniform Spinning Shaft with Nonlinear and Asymmetric Supports

In this paper, a hybrid approach was developed to investigate the transient responses of a multi span non uniform flexible spinning shaft with nonlinear and asymmetric supports. The non uniform spinning shaft with variable parameters was modeled as a Bernoulli Euler beam column with sectional constant cross section properties by the finite element method. The supporting stiffness behavior of the nonlinear supports was described as a piecewise linear and asymmetric model. The equations of motion in the matrix form of a multi span non uniform spinning shaft with nonlinear and asymmetric supports were formulated using Hamilton's principle and the assumed mode method. As an example, a spinning rocket with many variable stiffness supports was numerically simulated by the direct integration method. The transient response and dynamic behavior of this rotate dynamic system are analyzed.

ON THE AXIAL TRANSIENT RESPONSE ANALYSISOF THE SECTOR-SHAPED HYDRODYNAMIC THRUSTBEARING-ROTOR SYSTEM IN A TURBOEXPANDER

A model for the non-linear axial vibrations of the hydrodynamic thrust bearing-rotor system in a turboexpander is described. The axial transient process of the system is investigated. The time-dependent form ofthe Reynolds equation is solved by a finite difference method with successive overrelaxation scheme to obtain the hydrodynamic forces of the sector-shaped thrust bearing (SSTB). Using these forces, the equation of motion is solved by the fourth-order Runge-Kutta method and the Adams method to predict the transient behaviour of the thrust bearing-rotor system (TBRS).Also,the linearized stiffness and damping coefficients of the oil film hydrodynamic SSTB are calculated.The analyses of the axial transient response of the system under both linear and non-linear conditions are performed. The non-linearity of oil film forces can significantly contribute to the axial transient response. Conclusions obtained can be applied for evaluation of the reliability of the TBRS.

A NEW METHOD FOR SOLUTING TRANSIENT RESPONSE OF GENERALLY VISCOUS DAMPING MULTI-DEGREE SYSTEM

By means of the theory of composite-modality,the superposition principle of the vibra-tion mode of the linear system,and the analytical method of the original coordinate,a mathematical model of transient response to any stimulus for generally viscous damping multi-degree system was established.This method not only solves the problem of the transient response of displacement,but also calculates the transient response of the elastic force or the elastic couple of the system.

STEADY-SHEAR VISCOSITY AND TRANSIENT STRESS RESPONSE FOR ELASTO-THIXOTROPIC FLUIDS

A phenomenological model for dispersed systems which exhibit complex theological behaviour such as shear and time-dependent viscosity, yield stress, and elasticity is proposed. The model extends the Quemeda model to describe the viscosity function with a structural parameter λ which varies according to differ- ent kinetic orders of particle aggregation and segregation. The transient stress response is obtained by solving an instantaneous Maxwell model with an assumed shear modulus function G of the same form as the viscosity function η. Accuracy of the proposed model is verified experimentally with the results obtained for two oil (creosote)/water emulsions. The model that gives the best fit of experimental data appears to be the one with kinetic orders n = m = 2.

SUPPRESSION OF TRANSIENT RESPONSE OF A ROTOR IN ACTIVE VIBRATlON CONTROL

Transient response and its influence factors are investigated and a methodfor attenuating the transient response is developed by means of a time varying model.The system gain matrix is obtained by choosing weighting matrices and solving the timevarying Riccati equation. Control forces are applied to the system via a feed back loop.Comparisons of responses with and without control are made. The results show that thetransienl and steady state responses are significantly suppressed in the close loop systemand control forces are very small.

The impact of oceanic processes on the transient climate response: a tidal forcing experiment

In this study, the impact of oceanic processes on the sensitivity of transient climate change is investigated using two sets of coupled experiments with and without tidal forcing, which are termed ExpTide and ExpControl,respectively. After introducing tidal forcing, the transient climate response(TCR) decreases from 2.32 K to 1.90 K,and the surface air temperature warming at high latitudes decreases by 29%. Large ocean heat uptake efficiency and heat storage can explain the low TCR in ExpTide. Approximately 21% more heat is stored in the ocean in ExpTide(1.10×10^24 J) than in ExpControl(0.91×10^24 J). Most of the large ocean warming occurs in the upper 1 000 m between 60°S and 60°N, primarily in the Atlantic and Southern Oceans. This ocean warming is closely related to the Atlantic Meridional Overturning Circulation(AMOC). The initial transport at mid-and high latitudes and the decline in the AMOC observed in ExpTide are both larger than those observed in ExpControl. The spatial structures of AMOC are also different with and without tidal forcing in present experiments. The AMOC in ExpTide has a large northward extension. We also investigated the relationship between AMOC and TCR suggested by previous studies using the present experiments.