Ball lightning (BL) has been observed with two slitless spectrographs at a distance of 0.9 km. The BL is generated by cloud-to-ground strike. It moves horizontally during the luminous duration. evolution size, color, and light intensity reported in detail. spectral analysis indicates that radiation from soil elements present for entire lifetime BL.

Based on various radiation components in the spectra of lightning return stroke processes, temperature channel is diagnosed by different methods. Combining with synchronized electric field data and optical pictures channel, radii core current luminous are estimated. On basis above mentioned facts, according to heat conduction equation, distribution along radial direction also achieved. The results from six strokes show that for range 0.66–1.01 cm 5.03–7.96 cm, respectively, corresponding...

According to the spectra of cloud-to-ground (CG) lightning discharge plasma captured by a slit-less spectrograph and information synchronous radiated electric field, temperatures, total intensity spectra, peak value current its action integral channel have been calculated. Furthermore, correlativity these parameters has analyzed for first time. The results indicate that positive correlation in different strokes one CG lightning, temperature is direct proportion return lightning.

Using the spectra of a cloud-to-ground (CG) lightning flash with multiple return strokes and combining synchronous radiated electrical field information, linear charge density, channel radius, energy per unit length, thermal energy, dissociation ionization in discharge are calculated aid an electrodynamic model lightning. The conclusion that initial radius is determined by duration current confirmed. Moreover, correlativity several parameters has been analyzed first. results indicate total...

Cloud-to-ground lightning with six return strokes has been recorded by slitless spectrograph and the system of fast antenna slow antenna. The physical parameters discharge channel have obtained based on combination spectra synchronous radiated electric field. resistance internal field are studied as focus in this paper. results show that resistances per unit length order 10−2–10−1 Ω/m strengths 103 V/m.

Abstract According to the high time‐resolved spectra of two first and a subsequent return strokes following continuing current processes overlapped with M‐components in three natural cloud‐to‐ground lightning, correlation between total intensity ionic lines corresponding amplitude electric field change that apparent diameter discharge channel have been investigated. Linear correlations found for above sets parameters. The luminous properties along show both stroke decreases increasing height...

We study binding energies of both excitons and donors in a symmetric double quantum well the presence magnetic field applied parallel to growth direction. express wave functions as combinations Gaussian-type orbitals subband even odd parities, with variationally determined expansion parameters. By varying interwell barrier width sizes (hence coupling), we obtain ranging character from that for strongly coupled system two isolated single wells. The behavior function coupling, sizes, field,...

We study the drift-induced instability of surface modes in type II semiconductor superlattices, including both carrier-phonon and carrier-carrier scatterings. Stability-boundary curves are obtained for typical physical parameters. Amplification is possible experimentally achievable drift velocities.

Abstract Using high time‐resolved spectra and simultaneous records of the electric field change three negative cloud‐to‐ground (CG) lightning flashes with multiple return strokes, correlations between total intensity ionic lines in corresponding amplitude initial change, as well channel apparent diameter, have been analyzed. The analysis shows following: (1) is roughly proportional to lines. (2) a significant linear correlation diameter channel. (3) for 17 analyzed strokes decreases...

We study the up-down asymmetries in three-body anti-triplet charmed baryon decays of ${\bf B_c}\to{\bf B_n}MM' $ with $SU(3)_f$ flavor symmetry, where B_c}$ presents $(\Xi_c^0,-\Xi_c^+,\Lambda_c^+)$, while B_n}$ and $M^{(')}$ denote octet meson states, respectively. By assuming s-wave meson-pairs to be dominant constituents final state configurations, we can write spin-dependent decay amplitude into parity-conserving parity-violating parts, parametrized by 6 real parameters under $SU(3)_f$,...

Abstract Based on the high time‐resolved spectra of a cloud‐to‐ground lightning flash with seven return strokes captured by high‐speed slitless spectrograph, this work was first to use Saha‐Boltzmann plot method for determination stroke channel temperature. The temperatures ranged from 21370 26500 K. Compared traditional Boltzmann method, can provide more reliable temperature estimation channel. Analysis several strong along showed that changed little and there no obvious tendency increasing...

Mode structure and drift velocity thresholds for instability have been investigated the type-I superlattice, a new current-induced mode is found to exist high drifts. Simple separation of single-layer physics superlattice geometry has achieved, leading an analytical expression Giuliani-Quinn universality relations threshold curves mode.

Abstract A natural bipolar cloud‐to‐ground lightning with two return strokes has been recorded a slitless spectrograph. The subsequent positive stroke occurred retracing the preexisting channel created by first negative stroke. They both were followed long continuing current going M components. spectra of discharge for components spectral range from 400 to 1000 nm. analysis suggests that polarity and direction have little effect on structure spectrum, while strength, including magnitude...

We have developed a variational formalism for the calculation of binding energies hydrogenic donors in so-called ``dielectric quantum wells,'' where dielectric constant barrier material is significantly smaller than that well material, presence magnetic and electric fields applied along growth axis. derive an expression anisotropic electron--donor-ion interaction potential analytically by solving Poisson equation layered geometry quantum-well structures. Binding 1s 2p states are then...

A beam of ballistic electrons moving with a velocity about twice the Fermi (\ensuremath{\sim}${10}^{7}$ cm/s) respect to stationary electron gas is shown lead spontaneous generation plasmons.

We develop a theory for the electromagnetic response of semiconductor heterostructures based on Feibelman's d-function approach. This approach has been employed successfully in quantitative analysis reflectivity, transmittivity, photoemission, etc., spectra metal surfaces. As test this we examine GaAs-${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As heterojunction and compare our results with relevant experimental data.

We have developed a variational formalism to calculate the effects of electric and magnetic fields on confined hydrogenic donor states in asymmetric coupled double quantum well structures. It is demonstrated that an field applied along growth axis can easily shift electron wave function from one across center barrier into neighboring well, without ejecting state. Depending location structure, binding energy either increase or decrease under field, as had been found case single wells, but...

The channel core of natural negative cloud-to-ground lightning was recorded using a high-speed slitless spectrograph, which confirms the corona sheath model channel. By analyzing spectra and images at different stages, it is corroborated that ionic lines in are mainly due to core. Based on luminescence spectral characteristics, connection point downward moving leader upward connecting located, concluded current highest point. Above all, discovered there no obvious below point, means...

In certain new physics scenarios, a singly charged Higgs boson can couple to both fermions and $W^\pm Z$ at tree level. We develop strategies beyond current experimental searches using $pp\to jjH^\pm$, $H^\pm \to tb $ the Large Hadron Collider (LHC). With effective W^\mp tb$ couplings we perform model-independent analysis collision energy $\sqrt{s}=13$~TeV with integrated luminosity of $3~\text{ab}^{-1}$. derive discovery prospects exclusion limits for in mass range from 200~GeV 1~TeV....

We examine here the possibility of current-driven plasma instabilities in superconductors two temperature regimes. At low temperatures ($T\ensuremath{\approx}0$) an instability can be generated a layered system. Near critical ($T\ensuremath{\approx}{T}_{c}$) occur single superconductor for sufficiently large drifts which might achievable new high-${T}_{c}$ materials. These offer possibilities radiation-source device applications.