Magnetic Field Curves and Magnetic Equipotential Surfaces around Crossing Electrical Wires Replacing Classical Magnetic Field Lines

This article is based on a recent model specifically defining magnetic field values around electrical wires. With this model, calculations of field around parallel wires were obtained. Now, this model is extended with the new concept of magnetic equipotential surface to magnetic field curves around crossing wires. Cases of single, double, and triple wires are described. Subsequent article will be conducted for more general scenarios where wires are neither infinite nor parallel.

Importance and Design Requirements of Equipotential Connection in Lightning Protection Engineering

The role played by equipotential connection in lightning protection was summarized in terms of lightning protection,static electricity,electromagnetic shielding,protection from electric shocks,and earth fault protection.In addition,drawbacks of independent grounding and common grounding were concluded.According to standards and researches,such as Building Lightning Protection Design Standard （GB50057-2010）,further demands and rules of equipotential connection in lightning protection engineering were proposed,providing references for lightning prevention design,construction and examination by related scientific workers and staffs.

EPL-PRM:Equipotential line sampling strategy for probabilistic roadmap planners in narrow passages

Path planning is a crucial concern in the field of mobile robotics,particularly in complex scenarios featuring narrow passages.Sampling-based planners,such as the widely utilized probabilistic roadmap(PRM),have been extensively employed in various robot applications.However,PRM’s utilization of random node sampling often results in disconnected graphs,posing a significant challenge when dealing with narrow passages.In order to tackle this issue,we present equipotential line sampling strategy for probabilistic roadmap(EPL-PRM),a novel approach derived from PRM.This paper initially proposes a sampling potential field,followed by the construction of equipotential lines that are denser in the proximity of obstacles and narrow passages.Random sampling is subsequently conducted along these lines.Consequently,the sampling strategy enhances the likelihood of sampling nodes around obstacles and narrow passages,thereby addressing the issue of sparsity encountered in traditional sampling-based planners.Furthermore,we introduce a nodal optimization method based on an artificial repulsive field,which prompts sampled nodes to move in the direction of repulsion.As a result,nodes around obstacles are distributed more uniformly,while nodes within narrow passages gravitate toward the middle of the passages.Finally,extensive simulations are conducted to evaluate the proposed method.The results demonstrate that our approach achieves path planning with superior efficiency,lower cost,and higher reliability compared with traditional algorithms.

A Quasi-equipotential Field Simulation for Preform Design of P/M Superalloy Disk

On the basis of the minimum energy principle and the minimum resistance law,this article proposes a new method,termed equipotential field method,to design the proper preform for producing isothermo forged P/M superalloy disks. Using this new method,six variant preform contours are acquired with software ANSYS. The isothermal forging process of the P/M superalloy disk is simulated by using the industrial software MSC/Superform with thus obtained preforms so as to achieve the equivalent strain distribution in...

Interaction potential between micro/nano curved surface and a particle located inside the surface (II):Numerical experiment and equipotential surfaces

We verify the accuracy of the curvature-based potential.By means of the idealized numerical experiment,we show that the curvature-based potential is in good agreement with the numerical experiment,and the errors are within a reasonable range.Based on the curvature-based potential,the equipotential surfaces of particles are derived,and the intrinsic relations between the equipotential surfaces and Weingarten helicoids are shown.

Design of an Equipotential Shielding 1000 kV Capacitor Voltage Transformer

With the increase of the operating voltage and enlargement of the size of the capacitor voltage transformer(CVT),the additional measurement error caused by stray capacitance coupling and leakage current along the polluted surface of the CVT becomes noticeable.The equipotential shielding CVT(EPSCVT)was proposed and designed by the authors to mitigate these effects.An improved conceptual design option of the EPS-CVT is presented in this paper with special references to this study to improve the shielding effect without the increase of shielding capacitance.A proposed method of non-uniform capacitance configuration can improve the shielding effect significantly without an increase of the external shielding capacitance.Based on this achievement,the potential difference and the capacitive current exchange between the internal measuring system and external shielding systems are significantly reduced.In the evaluation of the shielding effect for the influence of stray capacitance,compared with a conventional CVT with equal capacitance,EPS-CVT can reduce the measurement error by two orders of magnitude.In addition,the measurement error caused by the leakage current can also be greatly reduced,especially for the reduction of the phase angle error.Based on the improved design method,a design scheme for an engineering application is proposed which can achieve effective shielding while ensuring as good a technical performance as the existing CVT.

A Unified Definition of Electrostatic and Magnetic Fields

This article originates from the observation that field lines are drawn using distinctive rules in magnetic field and electrostatic fields. It aims at reconciliating the definitions of these fields and thus reaching a consensus on the interpretation of field lines. Our unified field definition combines three orthogonal vectors and a unique scalar value. Field lines are then defined as isovalue lines of the scalar value, rendering it simpler to interpret in both field types. Specific to our field definition is the use of square root of vector’s cross product so that all vectors have the same physical unit. This enhanced field definition also enables a more efficient calculation of Biot-Savart law. This article is the first of a series allowing the drawing of isovalue contour lines.

Porous conductive interlayer for dendrite-free lithium metal battery

Lithium(Li) metal,possessing ultrahigh theoretical capacity and the lowest electrode potential,is regarded as a promising new generation anode material.However,the uncontrollable growth of Li dendrites during cycling process gives rise to problems as capacity decay and short circuit,suppressing the cycling and safety performances of Li metal battery.In this contribution,porous conductive interlayer(PCI),composed of carbon nanofibers(CNFs) and polyisophthaloyl metaphenylene diamine(PMIA),is developed to suppress Li dendrites and stabilize Li metal anode.PCI possesses the excellent conductive ability of CNFs and the preeminent mechanical properties of PMIA at the same time.When Li metal contacts with PCI during cycling process,an equipotential surface forms on their interface,which eliminates the tip effect on Li anode and homogenizes Li-ions flux in combination with the uniform porous structure of PCI.Employed PCI,the Li|Cu cell exhibits a remarkable cycling stability with a high average Coulombic efficiency of 97.5% for 100 cycles at 0.5 mA cm^(-2).And the Li|LiFePO_4 cell exhibits improved rate capability(114.7 mAh g^(-1) at 5.0 C) and enhanced cycling performance(78.9% capacity retention rate over 500 cycles at 1.0 C).This work provides a fresh and effective solving strategy for the problem of dendrites in Li metal battery.

Approximate analytical solution for seepage field of drained tunnel in vertically stratified phreatic aquifer

To explore the water table and water inflow after tunnel excavation in a vertically stratified phreatic aquifer,approximate analytical solutions for the steady-state water table and water inflow of a drained tunnel in a vertically stratified phreatic aquifer were obtained based on the Dupuit assumptions and the integral method.By comparing the approximate analytical solutions with numerical solutions,it was found that the relative error of the approximate analytical solution for the water table elevation is less than 10%,and the relative error of the approximate analytical solution for the water inflow is approximately 25%.The sources of the above errors are as follows:(1)At the lateral boundary of water replenishment,the water surface should be tangent to the horizontal line,but the water surface for the approximate analytical solutions has a gradient.(2)At the vertical boundaries near the tunnel,the total head is variable,but the total head for the approximate analytical solutions is assumed to be constant.(3)The Dupuit assumptions are applied in the flow domain near the tunnel.Although the relative errors of the approximate analytical solutions for the water table elevation and water inflow are evident,the lowered water table is reflected in the approximate analytical solutions.

The influence of isotope substitution of neon atom on the integral cross sections of rotational excitation in Ne-Na2 collisions

This paper applies the multiple ellipsoid model to the 16Ne （20Ne, 28Ne, 34Ne）-Na2 collision systems, and calcu- lates integral cross sections for rotational excitation at the incident energy of 190 meV. It can be seen that the accuracy of the integral cross sections can be improved by increasing the number of equipotential ellipsoid surfaces. Moreover, by analysing the differences of these integral cross sections, it obtains the change rules of the integral cross sections with the increase of rotational angular quantum number j＇, and with the change of the mass of isotope substitution neon atom. Finally, the contribution of different regions of the potential to inelastic cross sections for 20Ne-Na2 collision system is investigated at relative incident energy of 190 meV.

SOME ELECTROSTATIC PROBLEMS AND THEIR APPLICATIONS

Using the method for the classical electrostatic problems, some difficuties in modern phys-ics and engineering canbe overcome. By means of the concept of equipotential and the relatedconcept of perturbation of uniform field, the maximum field strength can be calculated at thetip of some dielectric or conducting bodies resting on the surface of a charged conductor. In2-dimensional cases of small semi-elliptical cylinder of dielectricor conducting material andcases of small part-cylindrical cylinder on a charged conductor, the concentration of chargescan be investigated to study gas ionization. These results have so far not yet been pub-lished in literature.