Two-dimensional Electrostatic Field Research Articles

Delegated Computation Architecture and Implementation for Numerical Simulation of Electromagnetic Comprehensive Performance Under the Framework of Blockchain

In view of the significant computational resources required for numerical simulation of electromagnetic comprehensive performance in modern electrical equipment, and the security and transaction fairness issues of existing delegated computation schemes, we propose a delegated computation scheme under the blockchain framework that is suitable for numerical simulation of electromagnetic comprehensive performance. This scheme combines the multi-level data characteristics of electromagnetic field numerical simulations with practical needs. Firstly, we propose a method for handling multi-layered data in delegated computation. Secondly, we design a delegated computation architecture that involves at least three participants and a detailed transaction mechanism, and develop three smart contracts to ensure data privacy protection and transaction fairness in delegated computation. Finally, the feasibility of the proposed scheme is proved by delegated computations for “Solving the Poisson equation of two-dimensional electrostatic field” and “Optimization of amorphous alloy transformer”. The research results have achieved a reliable and credible solution to the large-scale data computing problem in the field of numerical simulation of electromagnetic comprehensive performance, and provided a new theory and solution for data security in this field.

A note on the two-dimensional electrostatic field produced by a line charge near a dielectric wedge

Summary We shall consider the problem of determining the correct electrostatic field produced when an infinite two-dimensional line source is influenced by an adjacent infinite dielectric wedge. This result corrects a number of previous attempts at this problem, which are shown to be in error. The method avoids using the Mellin transform which has lead to some of these earlier errors. The method is used to solve a more general problem of the electrostatic field produced by an arbitrary number of line sources located in an arbitrary number of contiguous dielectric wedges.

High performance gridless ion mirrors for multi-reflection time-of-flight and electrostatic trap mass analyzers

The paper summarizes original developments of gridless ion mirrors for high-resolution multi-reflection time-of-flight mass spectrometers (MR TOF MS). Optimized mirror geometries and electrostatic field distributions reach up to the 5th order isochronicity with respect to the energy spread and up to the 3rd order full isochronicity per energy, spatial and angular spreads of ion packets. Using a retarding focusing field at the mirror entrance doubles the ion transport energy at limited highest voltages. In planar analyzers with a zig-zag ion path, quasi-planar mirrors eliminate the 2nd order dependence of the flight time on the ion packet width in the drift direction. Improved MR TOF analyzers of 1 m size provide well over one million aberration limit at realistic ion packets parameters past orthogonal accelerators. Because of high order isochronicity the aberration limit rapidly grows with the analyzer size or when using narrower ion packets. In experiments, improved analyzers with one meter size demonstrate up to 300 000 mass resolving power at the full mass range and 500 000 at the restricted mass range. Improved ion mirrors with two-dimensional electrostatic fields are applicable for TOF MS, electrostatic traps and open electrostatic traps in planar and hollow cylindrical geometries.

Applications of TEM imaging, analysis and electron holography to III-nitride HEMT devices

This paper reviews some of our recent studies of III-nitride high electron mobility transistor (HEMT) devices using advanced electron microscopy methods. Sample preparation protocols have been developed that can routinely provide thin, electron-transparent specimen regions of uniform thickness extending across entire HEMT devices. The use of focused-ion-beam (FIB) thinning facilitated access to specific device regions, although structural damage and imaging artifacts can result unless suitable precautions are taken during milling to minimize ion-beam damage. The extent of gallium-ion sidewall implantation during FIB milling, and surface damage caused by deposition of Pt protective layers, have been assessed. As-processed device structures have been examined by conventional diffraction contrast imaging as well as high-resolution phase contrast imaging, while nanospectroscopy and nanoscale elemental mapping have been used to measure local variations in chemical composition. Annealing of Ti/Al/Ni/Au ohmic contacts for AlInN/AlN/GaN devices lead to the formation of TiN contact inclusions that are invariably located at mixed-type threading dislocations originating from the underlying GaN layers. Some preliminary observations of device structures after extended periods of operation and after device failure have also been made. The technique of off-axis electron holography has been used to quantify two-dimensional electrostatic fields within cross-sectioned devices with nanometer-scale resolution. Polarization fields of 6.9 MV/cm and a two-dimensional electron gas of ∼2.1 × 10 13/cm 2 have been measured for an AlInN/AlN/GaN heterostructure. Methods suitable for in situ biasing of HEMT samples during electron holography observations have also been explored.

Born-Infeld corrections to Coulombian interactions

Two-dimensional Born-Infeld electrostatic fields behaving as the superposition of two pointlike charges in the linearized (Maxwellian) limit are investigated by means of a nonholomorphic mapping of the complex plane. The changes in the Coulombian interaction between two charges in Born-Infeld theory are computed. Remarkably, the force between equal charges goes to zero as they approach each other.

Two-dimensional electrostatic force field measurements with simultaneous topography measurement on embedded interdigitated nanoelectrodes using a force distance curve based method

Accurate simultaneous measurements on the topography and electrostatic force field of 500nm pitch interdigitated electrodes embedded in a thin SiO2 layer in a plane perpendicular to the orientation of the electrodes are shown for the first time. A static force distance curve (FDC) based method has been developed, which allows a lateral and vertical resolution of 25 and 2nm, respectively. The measured force field distribution remains stable as result of the well controlled fabrication procedure of Pt cantilever tips that allows thousands of FDC measurements. A numerical model is established as well which demonstrates good agreement with the experimental results.

Shape Transitions and Lattice Structuring of Ceramide-Enriched Domains Generated by Sphingomyelinase in Lipid Monolayers

Sphingomyelinases (SMases) hydrolyze the membrane constituent sphingomyelin (SM) to phosphocholine and ceramide (Cer). Growing evidence supports that SMase-induced SM→ Cer conversion leads to the formation of lateral Cer-enriched domains which drive structural reorganization in lipid membranes. We previously provided visual evidence in real-time for the formation of Cer-enriched domains in SM monolayers through the action of the neutral Bacillus cereus SMase. In this work, we disclose a succession of discrete morphologic transitions and lateral organization of Cer-enriched domains that underlay the SMase-generated surface topography. We further reveal how these structural parameters couple to the generation of two-dimensional electrostatic fields, based upon the specific orientation of the lipid dipole moments in the Cer-enriched domains. Advanced image processing routines in combination with time-resolved epifluorescence microscopy on Langmuir monolayers revealed: 1), spontaneous nucleation and circular growth of Cer-enriched domains after injection of SMase into the subphase of the SM monolayer; 2), domain-intrinsic discrete transitions from circular to periodically undulating shapes followed by a second transition toward increasingly branched morphologies; 3), lateral superstructure organization into predominantly hexagonal domain lattices; 4), formation of super-superstructures by the hexagonal lattices; and 5), rotationally and laterally coupled domain movement before domain border contact. All patterns proved to be specific for the SMase-driven system since they could not be observed with Cer-enriched domains generated by defined mixtures of SM/Cer in enzyme-free monolayers at the same surface pressure (Π = 10 mN/m). Following the theories of lateral shape transitions, dipolar electrostatic interactions of lipid domains, and direct determinations of the monolayer dipole potential, our data show that SMase induces a domain-specific packing and orientation of the molecular dipole moments perpendicular to the air/water interface. In consequence, protein-driven generation of specific out-of-equilibrium states, an accepted concept for maintenance of transmembrane lipid asymmetry, must also be considered on the lateral level. Lateral enzyme-specific out-of-equilibrium organization of lipid domains represents a new level of signal transduction from local (nm) to long-range ( μm) scales. The cross-talk between lateral domain structures and dipolar electrostatic fields adds new perspectives to the mechanisms of SMase-mediated signal transduction in biological membranes.

Computer support for “all-round” ECM processing of blades

A mathematical model has been created for complex simulation of the process of blade surface formation in unsteady mode. It is based on the assumptions of the one-dimensional theory in the feather regions of blade and the assumptions of two-dimensional electrostatic field in the edges vicinities. Laplace equation is solved by panel method. One-dimensional unsteady transfer equations are solved along edges by finite difference method.

Mass spectrometer based on conversion of spectra

This article presents the results of numerical investigations of mass analyzer parameters. The principle of mass spectrometer operation is based on the shock mechanism of the ion beam conversion of spectra. Mathematical simulation of the ion motion is carried out in the fields of a mass spectrometer consisting of an ion source converter and an energy analyzer with a two-dimensional electrostatic field and a plane of symmetry. A mass spectrometer of this kind is shown to have the following parameters: 1–1600 u—operational mass range, ∼1600 mm—relative mass resolving power, ∼300 mm—the maximum dimension of the mass analyzer. We have established the basic requirements to be met by the electric pulse generator that will provide the operation of the mass spectrometer under study. Keywords: Dynamikc mass analyzer; Ion source converter; Electric pulse generator; Mass resolution; Energy resolution

High order slices—a way to make an accurate approximation of two-dimensional electrostatic and magnetostatic fields near the axis of symmetry

High order slices—a way to make an accurate approximation of two-dimensional electrostatic and magnetostatic fields near the axis of symmetry

The two-dimensional electrostatic field configuration for parallel plate dust particle guide including end effects

Microdiameter dust particles in a viscous air medium are to be transported by a bi-planar arrangement of flat parallel plate electrodes. Sequential shifting of the static potentials on the electrodes is employed to guide the particles. The two dimensional configuration of these quasi-electrostatic fields in the semi-infinite guide composed of the parallel plate electrodes is theoretically and numerically examined. Loading effects of a two dimensional external rectangular cavity are incorporated in the theory. Numerical error resulting from the slow convergence properties of the series representing the fields near the boundaries of the guide is corrected. Field plots are presented and discussed in a qualitative manner for particle transport. The analytical fields are also compared with the fields obtained from employing the finite element method. Good agreement is shown.

The analogy between the calculation of a two-dimensional electrostatic field and that of a two-dimensional magnetostatic field

The analogy between the calculation of a two-dimensional electrostatic field and that of a two-dimensional magnetostatic field is exposed and yields a new theorem.

Time-of-flight focusing in a system consisting of electrostatic mirrors with two-dimensional fields

Time-of-flight properties of a system consisting of successively located mirrors with two-dimensional electrostatic fields having a common plane of symmetry are considered. The conditions for time-of-flight focusing in an angle of divergence of a charged particle beam and in the energy spread are found. The schemes of a time-of-flight spectrometer composed of cylindrical mirrors with external and internal reflection of a beam are calculated.

The charged particle time-of-flight and space focusing in a two-dimensional electrostatic field

Unknown earlier regularities of space and time-of-flight focusing of charged particle beams in electrostatic fields with a mid-plane have been revealed. The conditions of both space and time-of-flight high quality focusing are determined.

The ground state of a spin- 1/2 neutral particle with anomalous magnetic moment in a two-dimensional electrostatic field

The ground state of a spin- 1/2 neutral particle with anomalous magnetic moment in a two-dimensional electrostatic field

Ground state of a spin-1/2 neutral particle with an anomalous magnetic moment in a two-dimensional electrostatic field

It is shown that a relativistic spin-1/2 neutral particle with an anomalous magnetic moment moving in an x-y plane in a two-dimensional electrostatic field: E=(Ex(x, y), Ey(x, y), O) has (N-1)-fold degeneracy of the ground state. The degree of degeneracy of the ground state is defined by the value of the anomalous magnetic moment and a linear charge density of the filament creating this electrostatic field.

A finite element algorithm of plotting electric force line in two-dimensional electrostatic field computation

Based on the conjugate and harmonic properties of electric potential and flux, the nodal electric flux is numerically calculated through the curve integral of electric displacement, which is solved by numerical differentiation of the nodal electric potential calculated by the finite-element method. Therefore, the electric force line (actually the line of electric displacement or electric equi-flux line) may be plotted. The proposed algorithm has been made into a postprocessing code and put in to SEF2D, an effective finite-element software package for the computation of 2-D electrostatic fields. Four examples show that it is an effective postprocessing algorithm.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An improvement to the variational method for boundary value problems and its application to two-cylinder electrostatic lenses

One frequently uses the Ritz variational method to determine the coefficients of series obtained by separation of the variables when solving boundary value problems of electrostatic fields. In this paper an improvement to the variational method for determining the coefficients is proposed. When the solution of the problem is obtained numerically the calculational procedure for the new method is much simpler than that of the old, and the accuracy of the solution using the new method is better than that obtained using the least-squares method. By taking a problem of two-dimensional electrostatic fields as an example, the authors are able to understand the numerical calculational procedure of the new method. The results are compared with the true solution. The new method is applied to two-cylinder electron lenses and the electron optical characteristics are made clear.

Two-dimensional finite element charge-sheet model of a short-channel MOS transistor

A two-dimensional charge-sheet model for short-channel MOS transistors has been developed. The unique feature of the model is that the effect of channel inversion layer charge is included as a nonlinear integral boundary condition on the two-dimensional electrostatic field in the transistor. The average inversion layer charge density and source-drain current are obtained directly from the model rather than from the electron density or electron quasi-Fermi level. The model retains all of the physical detail of more complex two-dimensional models such as sensitivity to source-drain profile shape, channel profile, and oxide field shape. This allows the model to represent the changes in drain current associated with short-channel effects while still allowing simple comparison with long-channel models. For long-channel transistors, the results of this model are identical to Brews' long-channel charge-sheet model. The accuracy of this model is verified by modeling a sequence of transistors with channel lengths between 4.6 and 1.1 μm. In short-channel transistors, effects previously attributed to high field mobility are explained by simple two-dimensional electrostatics. The simulations produced using this model have been compared to experimental measurements on an array of n-channel MOSFETs; the model is in good agreement for transistors with channel lengths as short as 1.1 μm. In this verification process, the model represented accurately the onset of subthreshold current, channel-length-induced threshold voltage offset, and drain-field-induced output conductance changes. From studies of numerical accuracy, we conclude that the charge-sheet model can easily simulate drain current with an accuracy which exceeds that required for most applications. To obtain 5% accuracy for drain current, a 146 element mesh is sufficient. Refinement of the 146 element mesh to a 455 element mesh gives a current which is accurate to 0.16%. Average computer time for a high current solution is 2.5 min on a DEC-20. The numerical solutions were obtained using general-purpose software for solving elliptic partial differential equations. We have been able to solve problems with exact solutions to test the correctness and accuracy of our codes. We also can easily change the physics included in our model and the geometry of the transistor. The finite element method used allows refinement of oblique triangles which is important in achieving computational efficiency. The program is portable and has been run on a DEC-20, a VAX 11 780 , a Cyber 175 and a Univac 1108.

Synthesis of one- and twodimensional electrostatic field

The paper deals with the synthesis of one- and twodimensional electrostatic field caused by the boundary potential distribution. The problem has been reduced to the Fredholm integral equation of the first kind, which has been solved by means of Tichonov's regularisation method. Numerical calculations done for the homogeneous fields show the great usefulness of the proposed method.