K metal is the optimal anode for K-ion batteries because of its high capacity and low operating potential, but it suffers from fast fading safety issues due to an unstable solid electrolyte interphase (SEI) continuous K-dendrite growth. Herein, obtain promising potassium-metal batteries, a 3D polyvinyl-alcohol (PVA)-borax layer designed, which enables dendrite-free K-plating/stripping process. The protective possesses good wettability, diffusivity, structural stability, "uniform underneath...

A more accurate and comprehensive two-dimensional (2D) model of valved piezoelectric pumps is proposed using fluid-structure-electromagnetic coupling. The valve mesh offset avoids truncation in the fluid domain caused by collisions, offering a solution to solid-solid collision problem within domain. impact distance, drive parameters, structural parameters on output flow, internal pressure, flow field cavity valve-integrated pump systematically discussed. primary results are as follows: (1)...

Self-powered piezoelectric-biosensing textiles for the physiological monitoring and time-motion analysis of individual sports have been developed. The material system is composed tetrapod-shaped ZnO nanowires on common textiles. mechanism based coupling enzymatic reaction (LOx lactate) piezoelectric effect. After conformably attaching device to athlete, can monitor in real-time moving speed, frequency, joint angle, sweat lactate concentration athlete. whole monitoring/analysis process...

In order to improve the output capacity of a piezoelectric pump when transferring gas, this paper presents compact resonant diaphragm (hereinafter referred as pump), which is driven by rectangular vibrator. The structure can effectively release vibrating constraints vibrator, and enlarge its center displacement, so increase volume change rate chamber. Based on working principle pump, dynamic model for system established in paper, an analysis factors affecting frequency then conducted. We...

During the process in which a vacuum circuit breaker (VCB) switches off shunt reactor (SR), an overvoltage with high amplitude and frequency (HF) will occur because of current chopping multireignition. To reproduce this switching faithfully, voltage characteristics VCB were analyzed work, based on field test data from 220-kV substation Chongqing, China. Then, typical parameters three basic factors mentioned Helmer's model, value, dielectric dynamic insulation strength, HF quenching...

In high-rise concrete buildings, frame columns are usually made of higher strength than that horizontal beams or slabs to ensure sufficient axial compression ratio. However, relative lower used for casting can migrate into the column, causing a sandwich zone, which significantly reduce column loading capacity and may create potential safety issues. this paper, we employed piezoceramic-based active sensing approach provide an early determination presence low in beam-column joints. approach,...

In the field of controlled drug delivery system, there are still many problems on those reported micro-valves, such as small opening height, unsatisfactory particle tolerance and high cost. To solve above problems, a novel normally-closed piezoelectric micro-valve is presented in this paper. The was driven by circular unimorph vibrator natural rubber membrane with elasticity used valve stopper. axial displacement can be converted into large stroke stopper based hydraulic amplification...

Purpose This paper aims to investigate the tribological behavior and online infrared spectra of three types lubricating oils containing dinonyl diphenylamine (DNDA) antioxidant, which are mineral oil (MO), poly alpha olefin (PAO) trimethylolpropane trioleate (TMPTO), during friction process at high temperature (temperature rising first isothermal holding afterwards). Design/methodology/approach A platform low speed four-ball tribometer equipped with a controller combined spectrometer was...

A new concept of a dual-chamber serial-parallel piezoelectric pump with an integrated sensor (DSPPIS) is presented in this paper. By means dividing bimorph into actuator and sensor, sensing function onto the DSPPIS for flow rate measurement. prototype was manufactured assembled from finished bimorph. Then, frequency voltage characteristics were tested to evaluate performance serial parallel connection. Experimental results show that optimal range can be achieved determined by itself through...

Abstract A novel bionic piezoelectric actuator based on the walrus motion to achieve high performance large working stroke for micro/nano positioning systems is first proposed in this study. The structure of type described, and its principle presented details. An experimental system set up verify feasibility explore performances. Experimental results indicate that could realize with only one driving unit coupled clamping unit; maximum stepping displacement Δ L max = 19.5 μm case frequency f...

In this paper, we studied the effect of surface wettability on bubble tolerance a piezoelectric membrane pump, by applying super-hydrophilic or super-hydrophobic to key elements pump. Wettability for flow passage has direct influence air bubbles flowing in fluid. Based existing research results, first analyzed relationship between pump and Then made three prototypes where chamber walls valve plate surfaces were given different treatments. After output performance test, results demonstrate...

Abstract K metal is the optimal anode for K‐ion batteries because of its high capacity and low operating potential, but it suffers from fast fading safety issues due to an unstable solid electrolyte interphase (SEI) continuous K‐dendrite growth. Herein, obtain promising potassium‐metal batteries, a 3D polyvinyl‐alcohol (PVA)‐borax layer designed, which enables dendrite‐free K‐plating/stripping process. The protective possesses good wettability, diffusivity, structural stability, “uniform...

Signal injection method (SIM) is widely applied to the insulation parameters’ measurement in distribution network for its convenience and safety. It can be divided into two kinds of patterns: injecting a specific frequency signal or several frequencies’ groups, scanning scheduled scope. In order avoid disadvantages related researches, improved (ISIM), which characteristic transformer magnetizing impedance taken consideration, proposed. addition, optimization position has been accomplished,...

Gait analysis is of great importance to ensure that gait phases induced by robotic exoskeleton are tailored each individual and external complex environments. The objective this work develop a pressure insole system with redundant functionality for phase classification based on the ground reaction force unstructured terrains. A support vector machine optimized particle swarm optimization was proposed classifying four including initial contact, mid stance, terminal stance swing phase. Seven...