Intense low-noise terahertz generation by relativistic laser irradiating near-critical-density plasma

Low-noise terahertz(THz)radiation over 100 MV/cm generation by a linearly-polarized relativistic laser pulse interacting with a near-critical-density(NCD)plasma slab is studied by theory and particle-in-cell(PIC)simulations.A theoretical model is established to examine the dipole-like radiation emission.The THz radiation is attributed to the singlecycle low-frequency surface current,which is longitudinally constrained by the quasi-equilibrium established by the laser ponderomotive force and the ponderomotively induced electrostatic force.Through theoretical analysis,the spatiotemporal characteristics,polarization property of the THz radiation,and the relation between the radiation strength with the initial parameters of driving laser and plasma are obtained,which are in good consistence with the PIC simulation results.Furthermore,it is found by PIC simulations that the generation of thermal electrons can be suppressed within the appropriate parameter regime,resulting in a clear THz radiation waveform.The appropriate parameter region is given for generating a low-noise intense THz radiation with peak strength reaching 100 MV/cm,which could find potential applications in nonlinear THz physics.

Radiating frequency of three-loop mesoscopic LC circuit with mutual inductance obtained by IEO method

Instead of normally tackling electric circuits by virtue oI the Klrctllaott＇s theorem wnose aim is to uerlvc voxt^gc, electric current, and electric impedence, our aim in this paper is to derive the characteristic frequency of a three-loop mesoscopic LC circuit with three mutual inductances, e.g., for the radiating frequency of the three-loop LC oscillator, we adopt the invariant eigen-operator （lEO） method to realize our aim.

Metric of Accelerating, Radiating, Rotating, and Charged Black Hole in de Sitter Space

Metric of accelerating,radiating Kerr-Newman de Sitter black holes is derived in this letter.The metric involves(7+10)independent parameters.The volume density of space-time,and the electromagnetic potential in accelerating,radiating cases are the same as in nonaccelerating,nonradiating cases.The space-time related to acceleration is not asymptotic Minkowski flat.So the energy momentum tensor is not positive definite.

Hawking Evaporation for the 2+1 Dimensional Radiating Black Hole

By using a metric which is a counterpart of four dimensional Vaidya metric,we have investigated the Hawking evaporation of the 2+1 dimensional radiating black hole.The Hawking temperature of this radiating black hole is given.In a specific case,our result reduces to that of Banados.Teitelboim and Zanelli’s.

The Equivalent Parameters of an Inclined Slot in Two Crossed Waveguides with Radiating Slots

The effect of longitudinal-offset radiating slots on a centered-inclined feeding slot in the common broad wall of the two crossed rectangular waveguides is analysed quantitatively. The corresponding equivalent parameters are computed by employing the moment method. The numerical results of resonant length of the feeding slot, VSWR and coupling parameter are showed and compared with the case of no radiating slots and short-end. The agreement between theory and experiment is good.

Pit Chains Belonging to Radiating Graben-Fissure Systems on Venus: Model for Formation during Lateral Dyke Injection

Pits are circular to elliptical,steep-sided,flat-bottomed depressions interpreted to form from collapse into a cavity.They occur on Earth,Venus and Mars and range in diameter from;00 m to several kilometres(e.g.

Radiating Dyke Swarms in the BAT Region on Venus: A Study From the Helen Planitia Quadrangle

The Beta-Atla-Themis(BAT)region on Venus is characterized by large volcanic rises,major rift zones(chasmata),radiating,linear,and circumferential grabenfissure systems,and coronae.Its most prominent features

Computational Methods in the Theory of Synthesis of Radio and Acoustic Radiating Systems

A brief review of the works of the author and his co-authors on the application of nonlinear analysis, numerical and analytical methods for solving the nonlinear inverse problems (synthesis problems) for optimizing the different types of radiating systems, is presented in the paper. The synthesis problems are formulated in variational statements and further they are reduced to research and numerical solution of nonlinear integral equations of Hammerstein type. The existence theorems are proof, the investigation methods of nonuniqueness problem of solutions and numerical algorithms of finding the optimal solutions are proved.

Modeling of Radiating Aperture Using the Iterative Method

We are interested in this work to electromagnetic leakage, for example the door of the microwave oven (or shielding of electronic functions working in the microwave band containing holes for ventilation circuit) which must be transparent (chain link) but the level of electromagnetic leakage issued by this device must not exceed certain standards. This work started with this article in which we are interested in a simple structure consisting of a multilayer structure incorporating a radiating aperture. We show in this paper mainly the interests of this study and the limitations of using these structures. Modeling of this device is provided by the wave concept iterative procedure (WCIP) which is simple to implement and is characterized by the fast execution method. The validation of our work is carried out by comparing our results with those calculated by the Ansoft HFSS software which shows a good agreement.

Pointwise Estimates for Solutions to a System of Radiating Gas

In this paper we focus on the initial value problem of a hyperbolic-elliptic coupled system in multi-dimensional space of a radiating gas. By using the method of Green function combined with Fourier analysis, we obtain the pointwise decay estimates of solutions to the problem.

Irradiating an Iron Wire into a Laser-like Light Source

In a groundbreaking study published in Nature on November 2,Zhang et al.from the CAS Shanghai Institute of Optics and Fine Mechanics presents an innovative approach to generating laser-like light using a piece of wire(doi:10.1038/s41586-022-05239-2).By shining a laser on an iron wire,the researchers generated fast-moving electrons that amplified the electromagnetic waves created by the light interacting with the wire.This method could potentially surpass existing methods that use free-electron lasers,which are typically limited to large-scale facilities.

Influence of Heat-radiating on Multi-photon Compton Scattering High-energy Electron

Using the model of the inverse Compton scattering between high-energy electrons and heat-radiation photons, the influence of heat-radiating photons on multi-photon Compton scattering high-energy electrons is studied . The results show that the energy loss, power loss, light resistance and light pressure of the high-energy electron formed by heat radiating are all proportional to the temperature T4 of the vacuum cavity of the electron,the Lorentz factor γ2 of the high-energy electrons, the scattering section of the electron and the number of photons acting at the same time with high-energy electrons. A good method for lessening the energy loss of the high-energy electron by using the one-photon Compton scattering between high-energy electrons and heat radiation photons is proposed.

Non-Linear Synthesis Problems for Plane Radiating Systems According to the Prescribed Power Directivity Pattern

A variational formulation of the synthesis problem for plane radiating systems according to the prescribed power directivity pattern (DP) is considered. The function representing the mean-square deviation of the prescribed and synthesized power DPs and containing the additional term with squared norm of the current or field in the antenna aperture is considered as the criterion of optimization. Freedom to choose the phase DP is used to improve the proximity of the prescribed and synthesized DPs. In such formulation, the classes of non-linear problems, for which the non-uniqueness of solutions, their branching and bifurcation are characteristic, arise. The properties of solutions depend on the electric size of radiating system and prescribed power DP. From a practical point of view, the existence of different solutions creating the same or similar DPs, gives the opportunity to choose the solution that has a simpler implementation. The synthesis problems for plane radiating systems and plane arrays are considered.

Quantum Theory of a Radiating Harmonically Bound Charge

A phenomenological Hamiltonian giving the equation of motion of a non relativistic charges that accelerates and radiates is quantized. The theory is applied to the harmonic oscillator. To derive the decay time the physical parameters entering the calculations are obtained from the theory of the hydrogen atom;the agree- ment of the predicted value with the experiments is striking although the mathematics is very simple.

Convection of Radiating Gas in a Vertical Channel through Porous Media

The free convection flow of radiating gas between two vertical thermally conducting walls through porous medium in the presence of a uniform gravitational field has been studied. Closed form solutions for the velocity and temperature have been obtained in the optically thin limit case when the wall temperatures are varying linearly with the vertical distance. It is observed that the fluid velocity increases and the temperature difference between the walls and the fluid decreases with an increase in the radiation parameter. It is also observed that both the fluid velocity and temperature in the flow field increase with an increase in the porosity parameter. It is found that the fluid velocity decreases while the temperature increases with an increase in the thermal conductance of the walls. Further, it is found that radiation causes to decrease the rate of heat transfer to the fluid, thereby reducing the effect of natural convection.

Distributional Relations on Impulse Radiating Surface and Point Type Sources

The electromagnetic field relations are demonstrated on impulse radiating surface and point type sources, which are characterized by first and second order singularities at rest in a Schwartz-Sobolev space setting. The investigation starts with a general introduction to Schwartz-Sobolev distributions, the electromagnetic field equations and various modes of impulsive radiation. This is followed by an outline of temporal distributional relations in arbitrary media and distributional derivative operations on an arbitrary regular surface, all of which are employed in an investigation of impulse radiation mechanism on single and double layer sources. Similar steps are followed in a description of point distributions and investigation of impulse radiation mechanism on electric and magnetic point dipoles.

A Note on a Multi-Dimensional Radiating Gas Model with Nonlinear Radiative Inhomogeneity

In this paper,we consider the Cauchy problem of a multi-dimensional radiating gas model with nonlinear radiative inhomogeneity.Such a model gives a good approximation to the radiative Euler equations,which are a fundamental system in radiative hydrodynamics with many practical applications in astrophysical and nuclear phenomena.One of our main motivations is to attempt to explore how nonlinear radiative inhomogeneity influences the behavior of entropy solutions.Simple but different phenomena are observed on relaxation limits.On one hand,the same relaxation limit such as the hyperbolic-hyperbolic type limit is obtained,even for different scaling.On the other hand,different relaxation limits including hyperbolic-hyperbolic type and hyperbolic-parabolic type limits are obtained,even for the same scaling if different conditions are imposed on nonlinear radiative inhomogeneity.

Falkner-Skan aspects of a radiating(50%ethylene glycol D 50%water)-based hybrid nanofluid when Joule heating as well as Darcy-Forchheimer and Lorentz forces affect significantly

Falkner-Skan aspects are revealed numerically for a non-homogeneous hybrid mixture of 50%ethylene glycol-50%water,silver nanomaterials Ag,and molybdenum disul-fide nanoparticles MoS2 during its motion over a static wedge surface in a DarcyForchheimer porous medium by employing the modified Buongiorno model.The Brownian and thermophoresis mechanisms are included implicitly along with the thermophysical properties of each phase via the mixture theory and some efficient phenomenological laws.The present simulation also accounts for the impacts of nonlinear radiative heat flux,magnetic forces,and Joule heating.Technically,the generalized differential quadrature method and Newton-Raphson technique are applied successfully for solving the resulting nonlinear boundary layer equations.In a limiting case,the obtained findings are validated accurately with the existing literature outcomes.The behaviors of velocity,temperature,and nanoparticles volume fraction are discussed comprehensively against various governing parameters.As crucial results,it is revealed that the temperature is enhanced due to magnetic field,linear porosity,radiative heat flux,Brownian motion,thermophoresis,and Joule heating effects.Also,it is depicted that the hybrid nanoliquids present a higher heat flux rate than the monotype nanoliquids and liquids cases.Moreover,the surface frictional impact is minimized via the linear porosity factor.Furthermore,the surface heat transfer rate receives a prominent improvement due to the radiative heat flux inclusion.

基于GGE双标图的绿豆品种郑绿20号的丰产稳定性分析

郑绿20号在2019年河南省绿豆[Vigna radiate(L.)R. Wilczek]新品种鉴定试验中,田间性状表现优良、抗性好、产量高,4个参试点均比对照郑绿8号增产。为了进一步考察郑绿20号的丰产稳产性,采用GGE双标图分析2019年河南省绿豆新品种鉴定试验参试品种的农艺及产量性状,并对绿豆品种9个性状进行变异性和相关性分析。结果表明,郑绿20号的主茎分枝数、单株荚数、株高、主茎节数变异系数在试验点中变异程度较大;主茎节数与生育期呈显著正相关,与产量呈显著负相关,与株高呈正相关;产量与主茎分枝数、单株荚数、荚长、荚粒数呈正相关。丰产稳定性分析结果表明,郑绿20号为适宜推广的兼具丰产性和稳定性的绿豆新品种。

Visualizing the Spin & Radiation of the Extended Electron in Magnetic Field

This article presents illustrations of an extended model of the electron to visualize how it spins and radiates in the external magnetic field. A time-varying magnetic field B produces a rotational induced electric field E which rotates (spins) the electron about its axis. In time-constant magnetic field: the electron radiates the cyclotron radiation. In time-varying magnetic field: synchrotron radiation is generated. The couplings between spin, acceleration and radiation will be discussed.