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Cosmic rays around the so-called knee in the spectrum at around PeV primary energy are generally galactic in origin. Observations on the form of their energy spectrum and their mass composition are fundamental tools to understand the origin, acceleration and propagation mechanism of high-energy cosmic rays. In addition, it is required to find signatures to clarify the transition from galactic to extragalactic sources, which are believed to be responsible for the highest-energy cosmic rays above EeV. This brief review focuses on recent experimental results around the knee of the all-particle energy spectrum and composition in the energy range of the knee up to EeV energies. [ABSTRACT FROM AUTHOR]

The anomalous cosmic rays have been studied for about fifty years. Through theoretical and numerical models, we can learn how and where they are originating. When Voyager 1 and 2 spacecraft observed the solar wind termination shock, the main efforts were focused on try to explain the source spectrum and the acceleration mechanism. Nevertheless, there is another feature of the spectrum that need a better understanding, and it is related with the peak intensity in the energy spectrum, that occurred at different energies in consecutive solar minima. Qualitatively, it can be explained in terms of drifts and its relation with the acceleration process. In the past some works have been partially successful to explain the observations. In this paper we do another effort to explain the shift in the peak intensity of anomalous cosmic ray energy spectrum. We use a numerical model which includes diffusive shock acceleration, and the effects of the heliosheath. The present work analyzes the role played by different factors in the energy shift of the peak intensity between two successive minima, in particular the location of the region of observations with respect to the shock, the heliospheric distance, the effects of turbulence on the reduction of weak scattering drifts, as well as a possible latitudinal dependence in the ion injection on the shock. [ABSTRACT FROM AUTHOR]

In this work, we study the energy levels of electrons and holes of InAs quantum dots inside InP/InAs 0.25 P 0.75 /InP semiconductor nanowires. Taking into account the nonparabolicity of the dispersion law, the energy levels are calculated in two different ways. The change in the energy levels of a quantum dot at different positions inside a quantum nanowire is considered. The energy levels of semiconductor nanowire of various sizes are studied at a constant size. Changes in the energy levels of a quantum nanodot of a cubic shape are found when its size changes from 5 to 25 nm, located inside a quantum nanowire with a square section of 25 × 25 nm. [ABSTRACT FROM AUTHOR]

Background: Proton linear energy transfer (LET) is associated with the relative biological effectiveness of radiation on tissues. Monte Carlo (MC) simulations have been known to be the preferred method to calculate LET. Detectors have also been built to measure LET, but they need to be calibrated with MC simulations. Purpose: To propose and test a MC‐free method for determining LET from the measured integral depth dose (LFI) of the protons of interest. Method and materials: LFI consists of three steps: (1) IDD measurements, (2) extraction of energy spectrum (ES) from the IDD, and (3) LET determination from the extracted ES and the stopping power of each energy. To validate the accuracy of the extraction of ES, we use Gaussian ES to synthesize IDD, extract ES from the synthesized IDD, and then compare the original (ground truth) and extracted ES. LETs calculated from the original and extracted ES are also compared. To obtain the LET of protons of interest, we measure IDDs by a large‐area plane‐parallel ionization chamber in water. Finally, TOPAS MC is employed to simulate IDDs, ES, and LETs. From the simulated IDD, the extracted ES and LET are compared with the simulations from TOPAS MC. Results: From the synthesized IDDs, the LETs agreed excellently when the peak energies ≥10 and 1.25 MeV with depth resolutions 0.1 and 0.01 mm, respectively. For energy <1.25 MeV, even higher depth resolution than 0.01 mm is required. From the MC simulated IDDs, our track‐averaged LET excellently agreed with MC simulation, but not the LETd. Our LETd was smaller than MC simulated LETd in the shallow region but larger in the distal Bragg peak region. Conclusion: LET can be accurately determined from the IDD. This method can be used in the clinic to commission or validate LETs from other measurement methods or a treatment planning system. [ABSTRACT FROM AUTHOR]

Main cosmic rays exceeding energy of approximately 100 TeV are examined via the cascade of particles in the EASs. Any explanation of these particles requires a thorough understanding of the shape of the spectrum and the variations in the overall structure of cosmic rays. The interaction of elementary particles with the nuclei of air atoms inside the atmosphere produces huge amounts of charged particles. To characterize an energy spectrum features of cascade particles, a total number of elementary particles such as electrons, muons, pions and nuclei of iron atoms within the energy range (1014-1018) eV was calculated using MATLAB program. The theoretical results were compared with experimental measurements, which showed a decent compatibility of muon - electron within the range of energies mentioned above. [ABSTRACT FROM AUTHOR]

Nonlinear feedback between the gauge field and the material field can yield novel quantum phenomena. Here, the interplay between a density-dependent artificial gauge field and Bose–Einstein condensates (BECs) trapped in an optical lattice is studied. The energy spectrum and superfluidity represented by energetic and dynamical stabilities of the system are systematically discussed. A density-dependent artificial gauge field with a back-action between the BECs dynamics and the gauge field induces an effective atomic interaction that depends on the quasi-momentum and density of the condensates, resulting in a symmetry-broken energy spectrum and exotic stability phase diagram, that is, the system is only stable in a certain range of atoms density and under a limited lattice strength. The density-dependent artificial gauge field changes the sequence for the emergence of energetic and dynamical instability and the regimes of the energetic and dynamical instabilities are significantly separated, offering an efficient way to examine the energetic and dynamical instabilities of superfluids separately. In particular, the density-dependent artificial gauge field, as a mechanism for transferring momentum to the fluid, results in dynamic instability of the condensates even in free space. Our results provide deep insights into the dynamical response of superfluid systems to gauge fields and have potential applications for the coherent control of exotic superfluid states. [ABSTRACT FROM AUTHOR]

Geomagnetic radio emission from an extensive atmospheric shower (EAS) is calculated in a kinetic model where, in contrast to previous models, the radiation of each electron and positron of the shower disk is calculated taking into account their spatial distribution in the disk, the disk evolution along the EAS track, energy spectrum and multiple scattering. Radio emission spectra are found at distances of 100 and 800 m from the vertical EAS axis in the frequency range of 40 to 340 MHz with a resolution of 20 MHz. [ABSTRACT FROM AUTHOR]

The attenuation of vortex motion on the surface of shallow and deep water is investigated. The vortex flow is formed by two mutually perpendicular waves excited by plungers at a frequency of 6 Hz (wavelength λ = 5.6 cm) on the surface of water measuring 70 × 70 cm and depth h. After reaching a stationary state in the vortex system, the wave pumping is switched off and the attenuation of the surface flow is recorded. On the surface of shallow water, λ/2π ≈ h, when the characteristic size of vortices L exceeds the depth of the liquid, L h, the time dependence of the energy of the vortex flow Е(t) is described by an exponential function at all pumping levels while the dependence of enstrophy Ф(t) = Ω2(t) is exponential only in the range of wave vectors 0–0.3 cm–1. On the surface of deep water, λ/2π < h, L ≈ h the dependences Е(t) and Ф(t) are far from exponential in all wavenumber ranges. At high pumping wave amplitudes, the dependences Е(t) and Ф(t) are nonmonotonic, which can be attributed to the influence of volumetric flows. [ABSTRACT FROM AUTHOR]

This study investigates the critical significance of anode material selection in defining the energy spectrum and properties of X-ray photons in medical physics applications. Using the GATE platform and Monte Carlo simulations, a direct relationship between anode material atomic number and photon fluence is demonstrated. As the atomic number increases from Z = 29 (Copper) to Z = 74 (Tungsten), photon fluence rises by 62 %, indicating a substantial impact on X-ray production. Furthermore, the X-ray spectrum is affected by this material-driven changes, revealing a noticeable shift towards higher energy values: the mean energy of the continuous spectrum rises from 46.97 keV for Copper to 49.0 keV for Tungsten. The thermal properties of the material affect the temperature increase at the focal point. Rhodium and Molybdenum have a higher temperature rise than Copper (Cu) and Tungsten (W), because Cu and W have a greater thermal diffusion compared to other materials. These findings underscore the significance of anode material choice in optimizing X-ray systems which may enhance diagnostic accuracy and efficiency in diverse applications. [ABSTRACT FROM AUTHOR]

It was suggested the model of the non-concentric spherical core-shell quantum dot with hydrogenic impurity. It has been defined that the electron energy spectrum as a function of both an impurity and the core location. The splitting and degeneration of energy levels has been discussed. It is shown that displacing the core of a quantum dot or impurity in opposite directions can lead to alternate splitting and degeneracy of the energy levels of excited states. In certain configurations of arrangements, compensatory effects associated with the partial restoration of spherical symmetry in the field are observed.

We study the transport properties of Dirac fermions in ABC trilayer graphene (ABC-TLG) superlattices. More specifically, we analyze the impact of varying the physical parameters-the number of cells, barrier/well width, and barrier heights-on electron tunneling in the ABC-TLG. In the initial stage, we solved the eigenvalue equation to determine the energy spectrum solutions for the ABC-TLG superlattices. Subsequently, we applied boundary conditions to the eigenspinors and employed the transfer matrix method to calculate transmission probabilities and conductance. For the two-band model, we identified the presence of Klein tunneling, with a notable decrease as the number of cells increased. The introduction of interlayer bias opened a gap as the number of cells increased, accompanied by an asymmetry in scattered transmission. Increasing the barrier/well width and the number of cells resulted in an amplified number of gaps and oscillations in both two-band and six-band cases. We observed a corresponding decrease in conductance as the number of cells increased, coinciding with the occurrence of a gap region. Our study demonstrates that manipulating parameters such as the number of cells, the width of the barrier/well, and the barrier heights provides a means of controlling electron tunneling and the occurrence of gaps in ABC-TLG. Specifically, the interplay between interlayer bias and the number of cells is identified as a crucial factor influencing gap formation and transmission asymmetry. [ABSTRACT FROM AUTHOR]

Convective Self‐Aggregation (CSA) is a common feature of idealized numerical simulations of the tropical atmosphere in Radiative‐Convective Equilibrium (RCE). However, at coarse grid resolution where deep convection is not fully resolved, the occurrence of this phenomenon is extremely sensitive to subgrid‐scale processes. This study examines the role of mixing and entrainment, provided by the turbulence model and the implicit numerical diffusion. The study compares the results of two models, WRF and SAM, by varying turbulence models, initial conditions, and horizontal spatial resolution. At a coarse grid resolution of 3 km, the removal of turbulent mixing prevents CSA in models with low numerical diffusivity but is preserved in models with high numerical diffusivity. When the horizontal grid resolution is refined to 1 km, CSA can only be achieved by increasing explicit turbulent mixing, even with a small amount of shallow clouds. Therefore, the sensitivity of CSA to horizontal grid resolution is not primarily caused by the decrease in shallow clouds. The analysis of the total water path spectrum suggests that the amplitude of initial humidity perturbations introduced by convection in the free troposphere is the key factor. This amplitude is regulated by turbulent mixing and diffusion at small scales. Prior to the onset of CSA, increased mixing makes updrafts more sensitive to the dryness of the free troposphere, which strengthens the moisture‐convection feedback. This leads to an increased distance between convective cores and a stronger humidity perturbation in the free troposphere, which can destabilize the RCE state. Plain Language Summary: Convection transports moisture from the surface to the troposphere and forms clouds. Clouds developing in dry environments can be diluted by turbulent mixing, while mixing in moist environments favors their deepening. Turbulent mixing thus favors convection over moist regions, making them moister, while the opposite is true for dry regions. This phenomenon is known as the moisture‐convection feedback. In atmospheric models with a horizontal grid resolution of about 1 km, the feedback is represented by the turbulence model and the numerical discretization errors. This study found that when simulating deep tropical convection, the use of coarse grid resolution strengthens the moisture‐convection feedback, initially creating larger clusters of clouds separated by larger areas free of convection. In these areas where convection is suppressed, the upper troposphere will dry out. The amplitude of this area and its associated dry perturbation of the upper troposphere are key factors in determining whether convection will continue to be suppressed or if it will be able to penetrate the free troposphere. The final clustering of clouds into a single moist patch, known as convective self‐aggregation, depends on these conditions. Therefore, it is necessary to accurately represent sub‐grid scale mixing processes to capture the convective self‐aggregation phenomenon in high‐resolution atmospheric models. Key Points: The initial amplitude of humidity perturbations introduced by convection in the free troposphere is the key factor for the onset of convective self‐aggregation.Prior to the onset of self‐aggregation, this amplitude is regulated by turbulent mixing and numerical diffusion, rather than the amount of shallow clouds.Coarse resolutions impose larger mixing which increases the distance between convective cores and the associated humidity perturbation in the free troposphere. [ABSTRACT FROM AUTHOR]

The approximate bound state solutions of Schrödinger equation with linear combination of a four-parameter diatomic potential plus inversely quadratic Yukawa potential were obtained with the help of appropriate approximation to evaluate the centrifugal term. The Feynman path integral approach was used to obtain the analytical solutions. The energy spectrum and the normalized wave functions of the bound states are derived from the poles of the Green’s function and its residues. Particular cases of these potentials are also discussed briey and it is found that obtained results are in good agreement with those obtained in the literature. [ABSTRACT FROM AUTHOR]

New experiments are performed using a gamma ray spectrometer installed at the cosmic ray station in Apatity. The spectrometer monitors the differential spectrum of gamma radiation coming from the atmosphere in the 0.1–4 MeV range of energies. Analysis of the gamma radiation spectra in dozens of increases shows that the effect of growing gamma radiation during precipitation is not related to the presence of radionuclides, or the additional release of radionuclides from the soil. The characteristics of the gamma ray spectra indicate meteorological processes in the atmosphere as the primary cause of the increase effect. [ABSTRACT FROM AUTHOR]

The spin-polarized electronic energy spectra of the ZnSeS solid solution were obtained based on calculations for the supercell, which contains 64 atoms. At the first stage, the properties of the material based on the Mn:ZnSeS supercell, in which Mn replaces the Zn atom, were calculated. The calculation results reveal that the material is a semiconductor for both spin orientations. The second stage is based on the simultaneous presence of a Mn impurity and a cation vacancy. Comparing the results of the first two stages allows us to reveal significant changes in the electronic energy structure caused by the cation vacancy. The material with a vacancy exhibits metallic properties for both spin orientations. The third stage is implemented for the supercell without a vacancy, but under the action of hydrostatic pressure. The material exhibits semiconducting properties for both values of the spin moment. At the fourth stage, the Mn:ZnSeS supercell with a vacancy and under pressure is considered. In the presence of pressure and a VZn vacancy, the ZnMnSeS material exhibits metallic properties for both spin orientations. A material with a vacancy and under pressure can be characterized as a magnetic metal.

In this article, we have investigated an electron energy spectrum, optical absorption coefficients (OACs) and polarizability under the effect of the co-directed electric and magnetic fields in the multilayer spherical quantum antidot (MSQAD) Al0.3 Ga0.7 As/GaAs/Al0.3Ga0.7 As with off-center impurity. The calculations were done for different dot sizes within the effective mass approximation using the matrix method. The dependence of the total, linear, and nonlinear OACs on the incident photon energy is calculated considering the intraband electron quantum transitions. The donor polarizability and impurity binding energy as function of electric field intensity are obtained at different values of the magnetic field induction. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the D-dimension Feynman propagator to find the spectrum of non-relativistic energies and the corresponding wavefunctions of the ′ ′ ℓ ′ ′ states for the q-deformed modified Pöschl-Teller potential. We propose an approximation scheme for the centrifugal term of our potential. In addition, an appropriate space-time of Duru-Kleinert transformation has also been performed to convert the radial path integral into a manageable one. Furthermore, two special cases are to be considered, the Pöschl-Teller type potential and the generalized hyperbolic potential, as well as by a combination of illustration and comparison of some diatomic molecules, namely (HCL, NiC, CO, and I 2 ). It is found that this study is substantially marked, which communicated many important methods for solving the Schrödinger's equation. [ABSTRACT FROM AUTHOR]

The FY-3E satellite plasma analyzer marks China's first detection of the characteristics, occurrence, and development of the typical plasma environment in the dawn–dusk orbit space. It provides data source support for operational space weather alerts and forecasts, helps ensure the in-orbit safety of the satellite, and accumulates space environment detection data for space environment modeling and space physics research. This paper gives a detailed introduction to the detection technology adopted by the FY-3E satellite plasma analyzer. We calibrated its performance through a calibration experiment and then analyzed and compared it with similar instruments in China. It is indicated that the instrument is capable of measuring an ion energy spectrum of 24 eV~32 keV and an electron energy spectrum of 23.7 eV~31.6 keV, its field of view reaches 180° × 90°, and the inversed measurement range of spacecraft absolute potential is better than −30 kV~+30 kV. All these contribute to a notably improved technology for plasma and satellite potential detection of China's LEO satellites. [ABSTRACT FROM AUTHOR]

A comparative analysis of the spectra of primary cosmic rays (PCR) over Е0 and the spectra of variable stars over the periods is performed with for the purpose of determining the causes of irregularities in the PCR spectrum over Е0. The dependence between periods of variable stars and the maximum energy Е0 of PCR nuclei generated by such star types is shown. The irregularities in the PCR spectrum by Е0 are associated with the transition of one dominant star type to another with increasing Е0. The knee in the PCR spectrum at Е0 = 3–5 PeV is associated with a decrease in the contribution of SRB variability stars and the further increase in the contribution of stars of Myra-type variability to the PCR flux. The bump in the PCR spectrum with a maximum at Е0 = 80 PeV is formed by giant and supergiant stars of the Myra-type and SRC variabilities. [ABSTRACT FROM AUTHOR]

The results of laboratory experiments on determining the characteristics of convective turbulence over a heated metal surface at different heights and temperatures are presented. We used the high-speed thermography and a high-speed IR camera, which allowed imaging the temperature field of low-inertia paper targets hung up above the heated surface simultaneously throughout the vertical plane of the field of view of the camera. Based on fluctuations in the temperature field of the target surface, we determined the heat transfer coefficient, the convective flux intensity, the total flux, and the amount of heat generated during measurements at different heights above the surface. The energy spectra of convective turbulence are plotted under various turbulent conditions. The analysis of the turbulence spectra shows the presence of an inertial interval with a slope close to the 8/3 power law for all considered heights above the heated surface, temperatures, and turbulence conditions. Characteristics of convective turbulence we found can be used when testing different laser beam adaptive optics control systems, studying the propagation of vortex laser beams and combustion centers, which are also characterized by convective turbulence with further transition to atmospheric turbulence induced by the combustion energy. [ABSTRACT FROM AUTHOR]

Abstract Convective Self‐Aggregation (CSA) is a common feature of idealized numerical simulations of the tropical atmosphere in Radiative‐Convective Equilibrium (RCE). However, at coarse grid resolution where deep convection is not fully resolved, the occurrence of this phenomenon is extremely sensitive to subgrid‐scale processes. This study examines the role of mixing and entrainment, provided by the turbulence model and the implicit numerical diffusion. The study compares the results of two models, WRF and SAM, by varying turbulence models, initial conditions, and horizontal spatial resolution. At a coarse grid resolution of 3 km, the removal of turbulent mixing prevents CSA in models with low numerical diffusivity but is preserved in models with high numerical diffusivity. When the horizontal grid resolution is refined to 1 km, CSA can only be achieved by increasing explicit turbulent mixing, even with a small amount of shallow clouds. Therefore, the sensitivity of CSA to horizontal grid resolution is not primarily caused by the decrease in shallow clouds. The analysis of the total water path spectrum suggests that the amplitude of initial humidity perturbations introduced by convection in the free troposphere is the key factor. This amplitude is regulated by turbulent mixing and diffusion at small scales. Prior to the onset of CSA, increased mixing makes updrafts more sensitive to the dryness of the free troposphere, which strengthens the moisture‐convection feedback. This leads to an increased distance between convective cores and a stronger humidity perturbation in the free troposphere, which can destabilize the RCE state.

This paper delves into the fascinating realm of gust flow past a circular cylinder, unveiling the dynamic interactions and key features that influence the system's behavior. In this study, ANSYS Fluent is used to perform numerical simulations based on finite volume method. The aim is to investigate the temporal evolution of the aerodynamic forces at different Reynolds numbers (Re) at different gust frequencies. In this study, gusts are generated by harmonically changing the direction of the inlet velocity at different frequencies. Unlike uniform flow, vortices are shed simultaneously from the upper and lower surface of cylinder, sometimes with equal strengths and sometimes with varying strengths depending upon the gust frequency. Cl, Cd and Strouhal number values increase with gust frequency corresponding to any Reynolds number. However, the values remain less than no-gust case under similar flow situations. Fast Fourier transform analysis has been used to examine the energy spectrum and kinetic energy contours of vorticity and turbulence to gain further insight into fluid physics. The results of this study provide valuable insight into the physics of gust flow and circular cylinders.

INTRODUCTION: As a renewable and clean use of energy, wind power generation has a very important role in the new energy generation industry. For the many parts of various wind turbines, the safety and reliability of wind turbine blades are very important. OBJECTIVES: The energy spectrum simulation algorithm included in the wavelet analysis method is used to simulate and analyzewind turbine blade damage, to verify the correctness and validity of wind turbine blade damage analysis. METHODS: Matlab simulation is used to introduce the experiments related to the static and dynamic detection of fiber grating sensors, analyze the signal characteristics of the wind turbine blade when it is damaged by the impact, and provide a basis for the analysis of the external damage of large wind turbine blade. RESULTS: The main results obtained in this paper are the following. By analyzing the decomposition of wavelet packets, the gradient change of wavelet impact energy spectrum before and after the wavelet damage was obtained and compared with the histogram, and the impact energy spectrum of each three-dimensional wavelet energy packet in the image was compared and analyzed, which can well realize the recognition of wavelet damage gradient for solid composite materials. CONCLUSION: With the help of Matlab simulation to collect the impact response signal, using the wavelet packet energy spectrum method to analyze the signal, can derive the characteristics of wind turbine blade damage.

The paper presents the results of a study of the charge and energy characteristics of multiply charged ions excited on the surface of a single-element and hydrogen-containing multi-component element targets under the influence of laser radiation with a power density (q=108-1012 W/cm2). It has been experimentally shown that, for all used values of q laser radiation, laser-induced plasma from gas-containing targets is characterized by a lower relative yield (dN/dE) of multi-charged ions with a charge number of Z>+3, compared to the plasma produced on the surface of the single element target. Moreover, the tendency to reduce dN/dE of multi-charged ions of the multi-element target, in comparison with the relative yield of ions from the plasma of the single-element target, is more significant and it depends on the charge of the excited ions. The increase in the charge and energy state, duration, and yield of ions of the heavy component, which occurs with an increase in the content of the light component in the target, has been established. This is explained by a decrease in the efficiency of recombination processes caused by an increase in the expansion velocity of a plasma plume due to a decrease in its average mass.

Background252Cf is a high-intensity isotope neutron source in great demand for scientific research and device development. Currently, it is produced only in high-flux reactors in the United States and Russia, which rely on imports in China for a long time.PurposeThis study aims to analyze key factors of 252Cf production by irradiation based on the preliminary design scheme of a high-flux fast reactor.MethodsFirstly, an irradiation target design was implemented, and the fission deposition energies and energy spectra were calculated for three irradiated target designs using different zirconium hydride and Eu2O3 absorbers. Then, burnup calculations for heavy and light curium targets were performed using a burnup calculation program STEP, which was developed by China Institute of Atomic Energy. The experimental values for 252Cf produced by irradiation in the United States were then compared. Finally, the calculation results were analyzed using the energy spectrum and cross-section.ResultsComparison results between simulation and experiment indicate that 245Cm is the key nuclide affecting the production of 252Cf. Utilizing the hard-energy spectral characteristics of high-flux fast reactors can effectively reduce the fission loss of the target and increase the production of 252Cf.ConclusionsThe calculations and analysis in this study can provide theoretical and technical support for the high-flux fast neutron research reactor irradiation production of 252Cf.

Background. The relevance of studying the semi-conductor-metal transition of gold nanotubes is caused by the high rate of miniaturization of electronic devices. The purpose of the study is to understand at what length of the nanotube the transition from the semiconductor state to the metallic state occurs. Materials and methods. In the process of studying gold nanotubes of chiralities (6.0) and (7.0) within the Hubbard model in the approximation of static fluctuations, a transition was made to the nanotube model in order to be able to mathematically describe our nanoparticles within the framework of quantum field theory. An important role is played by the π-electron, which has transport properties. The task of the work is to construct energy spectra and study the dynamics of the change in the width of the bandgap energy. Results. According to the obtained equations of motion from the Hubbard model Hamiltonian, anticommutatory Green functions were obtained in the approximation of static fluctuations, energy spectra were constructed from them, from which the lid and bottom were found for the valence band and conduction band, respectively, according to which the width of the band gap of chirality nanotubes was determined (6.0) and (7,0). Conclusions. From the results obtained, it can be concluded that as the number of atoms in the golden nanotube of chiralities (6.0) and (7.0) increases, the width of the forbidden energy zone decreases down to zero, which in turn causes the transition from the semiconductor state to the metallic one. Examining the graphs of the dynamics of the distance between the lid and the bottom of the lower and upper Hubbard subzones, we can conclude that the oscillation of the conductor-metal-semiconductor-metal does not occur.

The IceCube Neutrino Observatory is a cubic-kilometer Cherenkov detector that is deployed deep in the Antarctic ice at the South Pole. A square kilometer companion surface detector, IceTop, located directly above in the in-ice array, measures cosmic-ray initiated extensive air showers with primary energies between 100 TeV and 1 EeV. By combining the events measured by IceTop and the in-ice detectors of IceCube in coincidence, we can reconstruct the energy spectra for different primary mass groups. Therefore, we provide information about the origin of cosmic rays, in particular, in the transition region from galactic to extra-galactic origin of high-energy cosmic rays. In this contribution we present recent experimental results, as well as prospects by the foreseen enhancement of the surface detectors of IceTop and the future IceCube-Gen2 surface array. [ABSTRACT FROM AUTHOR]

Monte Carlo simulations were used to evaluate the photon beam softening characteristics of medical electron linear accelerators operated in flattening filter-free mode (FFF) under different energies and field sizes. Using the parameters of the Varian Edge accelerator and measured data in our hospital, a 6 MV flattening filter (FF), a 6 MV FFF, and a 10 MV FFF model in the accelerator head were constructed using the general Monte Carlo program EGSnrc/BEAMnrc. Using EGSnrc/DOSXYZnrc, three modes were characterized based on percentage depth dose (PDD) and off-axis ratio (OAR), which were compared with simulation data to determine source parameters. By using the above models, we obtained PDDs for three modes of inhomogeneous phantoms (water-bone-lung-water) in two field sizes, and the energy spectrum was calculated from phase space files, then the FFF photon beam softening properties were analyzed. In the inhomogeneous phantom, the PDD trends of the three photon-beam modes are similar, but the fluctuations are greater at small fields. In contrast to FF mode, FFF mode contains more low-energy photons and less head scattering. At low energy and small field, photon beam softening caused by the 6 MV FFF mode does not bring about a noticeable dose effect, however, at high energy and large field, the beam softening effect is gradually apparent. FFF photon beams have a steeper dose drop than FF beams, especially at small fields and low energy, which makes them evidently advantageous in clinical settings; however, at large fields and high energies, FFF photon beams appear to have significant softening characteristics, particularly in low-density areas, requiring careful consideration of the choice of clinical planning modality. [ABSTRACT FROM AUTHOR]

Radio emission of the electron excess of the extensive air shower (EAS) charge is calculated in the kinetic model, where in contrast to the previous models, radiation of each excess electron of the shower disk is calculated taking into account their spatial distribution in the disk, the disk evolution along the EAS track, the energy spectrum, and multiple scattering. The radio emission spectra are found at distances of 100, 200, 300, and 400 m from the vertical EAS axis in the frequency range of 20–360 MHz with a resolution of 20 MHz and with a resolution of 2 MHz at distances of 100 and 800 m in the frequency range of 20–320 MHz. [ABSTRACT FROM AUTHOR]

The summer mesopause at middle and high latitudes is the coldest place on Earth, and atmospheric gravity waves are responsible for the emergence of this extreme thermal phenomenon. Although the main physical mechanism behind the latter is understood, a deeper insight into it can be gained from the investigation of the mesoscale energy spectrum. In this work, we decompose the frequency spectra into divergent and rotational parts and find that their energy contributions are equipartitioned at high frequencies. This mesoscale energy equipartition is a feature of stratified turbulence and illustrates the complexity of the mesoscale dynamics in the summer mesopause region. We also analyze the power spectra of observed and simulated mesoscale zonal and meridional winds at middle latitudes in the Southern Hemisphere and show that stratified turbulence plays a role in the mesopause region during summer. Plain Language Summary: Given its complexity to be measured at different spatio‐temporal scales, the exploration of the mesosphere and lower thermosphere remains an active area of research. In this work, we have applied velocity filtering techniques to both multistatic specular meteor radar measurements and global circulation model simulations to analyze horizontal wind frequency spectra over southern Patagonia. We consider the theory of layered anisotropic stratified turbulence to study the summer mesopause region and hypothesize that this type of turbulence (in the statistical sense) plays a role in the transition of internal gravity waves to small‐scale turbulence. Key Points: Spatially filtered horizontal wind residuals are explored for the first time at mesopause altitudes over PatagoniaFrequency spectra of horizontal wind residuals follow a −2 slopeSimulated divergent and rotational parts of the mesoscale kinetic energy are equipartitioned at high frequencies [ABSTRACT FROM AUTHOR]

In this contribution, we present the latest updates on the energy spectrum characterization obtained with data from the Pierre Auger Observatory. We present the measurement of the spectrum from 6 × 10 15 eV up to above 10 20 eV, obtained by combining five different methods. The exposure of over 80,000 km2 sr yr has been accumulated above the ankle region, making this the best estimate of the spectrum ever achieved in this energy range. The wide zenith angle range covered by the Pierre Auger Observatory and the enormous exposure also allow us to measure the spectrum in different regions of the sky. After a description of the techniques used to reconstruct the spectrum, the spectral features will be presented, and the astrophysical implications of the spectral shape will be briefly discussed. [ABSTRACT FROM AUTHOR]

Four tropical transition (TT) events in the North Atlantic basin are simulated with the Weather Research and Forecasting (WRF) and the HARMONIE‐AROME (HAR) models to study the main features of the horizontal kinetic energy (HKE) spectra of these kinds of high‐energetic atmospheric system. Though most of the times similar results are obtained with both models, HAR shows a more intense filtering and numerical dissipation, whereas WRF tends to represent overenergized spectra in the synoptic scale and especially at smaller wavelengths. Predictability is dissimilar for the four TTs studied due to the different spectral curve slope obtained for each case, ranging from unlimited to very poor predictability at synoptic scale. Additionally, an increased HKE is presented in the middle–upper troposphere spectra. A deep analysis of the different terms involved in the equation of the spectral energy budget is presented through a detailed study of one of these TTs. The role of all of them is studied, connecting the energy spectra and the meteorological processes involved. The energy budget terms related to the nonlinear spectral transfer, the three‐dimensional divergence, and diabatic process tendencies are identified as the key ones, whereas the potential and kinetic conversion terms and the vertical flux HKE and pressure divergence terms play a secondary role on modulating the spectrum behaviour. The major energetic contributions are found at the synoptic scale, but results show that a two‐dimensional energy cascade does not fully capture the whole spectrum of a TT. The role of convection, latent heat release, and moist convection outbursts is sketched and a link within different vertical levels is found. Results show that a high‐energetic system, such as a TT, can effectively alter the atmospheric energy behaviour. [ABSTRACT FROM AUTHOR]

A method is proposed to quantitatively capture the unique characteristics of strong ground motions using idealized pulses. The pulse motions described here use limited parameters (PGA or PGV and duration of pulse) in contrast to the methodologies involving several parameters and assumptions. This simple method also provides an advantage to specify hazard in regions where a few recorded ground motions are available; ballpark values of pulse parameters can be used to arrive at the response spectra required in the seismic design. The physics of ground shaking is captured here mathematically using idealized pulses only, without any "random shaking." [ABSTRACT FROM AUTHOR]

In this paper, we study the Dirac particle near the event horizon of the charged Bañados-Teitelboim-Zanelli (BTZ) black hole and Reissner–Nordström (R-N) black holes to obtain its energy spectrum for discussing the weak gravity conjecture (WGC). The corresponding energy has both real and imaginary parts. We encounter the quasi-normal mode. Because the considered black holes have mass M and charge Q , this property allows us to examine the WGC using the energy spectrum with specific conditions. We attempt to investigate the WGC for these black holes by utilizing the Dirac particle energy spectrum obtained near charged black holes. Also, we impose conditions on the energy spectrum of particles for which the WGC holds for charged black holes, i.e. Q ∕ M > 1. To approve the WGC near the event horizon of black holes, we determine that the Dirac particle has a specified charge viz q = − 1 2 ω and q = − 1 ln ( r + ℓ) for R-N and charged BTZ black holes, respectively. [ABSTRACT FROM AUTHOR]

We study an analytically solvable pseudoscalar interaction potential for the one-dimensional stationary Dirac equation, which consists of power terms proportional to , , and . This potential is classified as conditionally exactly solvable due to the fixed strength of the first term at a specific constant. We present the general solution to the Dirac equation in terms of non-integer index Hermite functions, which are distinct from the conventional integer index Hermite polynomials. We analyze the energy spectrum of the bound states and the eigenfunctions and compare the results with the case without the term. [ABSTRACT FROM AUTHOR]

The prediction of reactor antineutrino spectra will play a crucial role as reactor experiments enter the precision era. The positron energy spectrum of 3.5 million antineutrino inverse beta decay reactions observed by the Daya Bay experiment, in combination with the fission rates of fissile isotopes in the reactor, is used to extract the positron energy spectra resulting from the fission of specific isotopes. This information can be used to produce a precise, data-based prediction of the antineutrino energy spectrum in other reactor antineutrino experiments with different fission fractions than Daya Bay. The positron energy spectra are unfolded to obtain the antineutrino energy spectra by removing the contribution from detector response with the Wiener-SVD unfolding method. Consistent results are obtained with other unfolding methods. A technique to construct a data-based prediction of the reactor antineutrino energy spectrum is proposed and investigated. Given the reactor fission fractions, the technique can predict the energy spectrum to a 2% precision. In addition, we illustrate how to perform a rigorous comparison between the unfolded antineutrino spectrum and a theoretical model prediction that avoids the input model bias of the unfolding method.

Is this article simulation of statistical measurements is performed on the basis of which the analysis of the standard deviation of the obtained results is carried out. It is shown that the standard deviation is minimum and independent from measurement duration while an object is in the state of equilibrium. For objects in a stationary non-equilibrium state the standard deviation depends on the duration measurements and the parameters of the state. The influence of these factors on the standard deviation is assessed with equation which includes the relaxation time. The value of the relaxation time is determined by approximating the energy spectrum of the studied signals. The analysis of energy spectra showed that the spectrum of white noise is inherent in objects in equilibrium; the flicker component of the spectrum occurs when the state of the object deviates from equilibrium.

SIIVOPEC Zhenhai Refining & Chemical Company has two sets of S Zorb units,1.5 MM TPY and 1. 2 MM TPY. At the end of operation, the pressure drops of the reactor filters of the two units are 33 kPa and 100 kPa respectively. There is no significant difference between the two in terms of operating parameters, filter body composition, and adsorbent composition, except for the number of filter elements. To explore the fundamental reason for the significant diiference in pressure drop between the two reactor filters, the two sets are dissected. The appearance analysis shows that the structure of the filter element is complete and there is no rusting phenomenon. There are significant diiferences in the pores and permeability of the filter element under diiferent pressure drops. The crushing strength test shows that the strength of the filter element meets the requirements and has a certain improvement. The analysis of pore size and permeability shows that the adsorbent is mainly distributed on the outer surface of the filter element at low pressure drop, but at high pressure drop, the adsorbent infiltrates into the inside of the filter element, causing a significant decrease in permeabiliiy and dificulty in restoring it through reverse blowing. The energy spectrum analysis of the outer surface of the filter element indicates that the substance on the outer surface of the filter element is an adsorbent, and the filter element itself has not undergone sulfide corrosion. [ABSTRACT FROM AUTHOR]

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The work is devoted to the study of the effect of an electric explosion on the selectivity of the destruction of quartz raw materials. The object of the study is quartz ore of the Nadyrbay deposit of the Republic of Kazakhstan. An electrohydroimpulse plant for crushing and grinding quartz raw materials has been developed and assembled. Using the electrohydroimpulse method, the granulometric composition of quartz can be adjusted. This makes it possible to adjust the magnitude of the voltage in the discharge channel and time. In this technology, quartz ore processing was carried out with an increase in the discharge voltage of the storage from 14 kV to 25 kV, the length of the interelectrode distance from 8 to 12, the capacitance of the capacitor 0.5 μF, 0.75 μF and the processing time of 5 min. Using the electrohydroimpulse method, quartz ore particles with an initial fraction of 5 mm, 10 mm and 1 mm were crushed to 0.8. The results of the grinding of quartz raw materials with the influence of an underwater electric explosion in a liquid medium allowed us to determine the degree of grinding of the material. The obtained results can be used in the course of studying the characteristics of crushing and grinding of ores. In the food industry, quartz sand within 0.25–0.5 millimeters can be used as a filler to create filters for water purification, as well as products from oil, industrial effluents, etc. Particles ranging in size from 0.5 to 1 millimeter can be used for rough processing of metal, stone and glass. The structural and quantitative analysis of powdered quartzite samples was made using a scanning electron microscope and the stoichiometry of the elements was calculated. [ABSTRACT FROM AUTHOR]

The energy spectra and optical absorption spectra of isomers Nos. 1, 6, 16 and 46 of fullerene C90 are calculated. Due to the comparison of theoretical and experimental optical absorption spectra, three previously synthesized isomers of C90 fullerene have been identified. The calculations are carried out within the framework of the developed approach, taking into account the intra-node Coulomb interaction of π-electrons, which plays a crucial role in the formation of the electronic and optical properties of fullerenes. [ABSTRACT FROM AUTHOR]