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Intersubband optical absorption in Gaussian GaAs quantum dot in the presence of magnetic, electrical and AB flux fields
摘要： We theoretically study the spectral properties of single electron two-dimensional (2D) Gaussian quantum dot (GQD) in the presence of applied magnetic, electrical field and along with an Aharonov–Bohm (AB) flux field. We have calculated the exact solutions for the normalized wave functions and energy levels by using the Nikiforov–Uvarov (NU) method within the effective-mass approximation and compared the results with parabolic potential (PP) model. Based on the calculated energy spectrum and the wave function, we have obtained the intersubband light absorption coefficient eK e?TT and the value of absorption threshold frequency e?T. The main and important object of the present work is to study the effect of the GQD size eRT and the strength of the potential eV0T on the energetic spectrum and the absorption threshold frequency e?T. According to the present work results, the ground state (GS) energy and the e?T shows that the size of the QD, depth of the potential and electric field plays an important role.
关键词： Absorption threshold frequency,Energetic spectrum,Magnetic,Electrical and AB flux fields,Gaussian quantum dot
更新于2025-09-16 10:30:52
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Comparaison in vitro des flux de bulles avec le Laser Thulium Fibré Superpulsé selon le diamètre de fibre laser (150 μm vs 272 μm) et le milieu d’activation (sérum physiologique, produit de contraste iodé, eau pour préparation injectable, urine)
摘要： Le Laser Thulium Fibré (TFL) représente une alternative au laser Holmium:YAG pour la lithotritie endocorporelle, permettant d’utiliser des fibres laser (FL) de diamètres inférieurs à 200 μm. L’objectif était de comparer in vitro les dimensions et durée des flux de bulles (FB) entre FL de diamètre 272 μm (272CDF) et 150 μm (150CDF) avec le TFL selon le milieu d’activation.
关键词： lithotritie endocorporelle,Laser Thulium Fibré,flux de bulles,fibres laser
更新于2025-09-16 10:30:52
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Photomorphogenesis of wheat sprouts with LED irradiation of different intensities
摘要： Definition of the growth and development characteristics of plants in varied light conditions is a key factor for the creation of highly efficient light facilities for plant cultivation. Experimental research was conducted using an LED irradiation facility with photosynthetic photon flux densities ranging from 0 to 261 lmol m?2 s?1 and a continuous spectrum with maxima at 445 and 600 nm. Under the maximum photosynthetic photon flux density (261 lmol m?2 s?1) wheat germs demonstrated diminishing leaf surface with high values of specific leaf area, enhanced pubescence of ground tissues, increases in the number of stomata on the upper epidermis and palisade, and an increase in the thickness of the leaves as well as an increase in carotenoids but a decrease in the chlorophyll atb/carotenoids relation. It was revealed that the optimum level of photosynthetic photon flux density for the referred spectrum was in the range from 82 to 100 mmol m?2 s?1, which may enable a reduction of irradiance under specific conditions during early development with no harm to the plants while minimizing energy consumption during cultivation.
关键词： photosynthetic photon flux density,photomorphogenesis,wheat sprouts,LED irradiation,plant cultivation
更新于2025-09-16 10:30:52
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Effect of gravity and electromagnetic field on the spectra of cylindrical quantum dots together with AB flux field
摘要： In this work, we study the spectral properties of electron quantum dots (QDs) confined in 2D parabolic harmonic oscillator influenced by gravity, external uniform electromagnetic field together with an Aharonov–Bohm (AB) flux field. Our calculations are based on the Nikiforov–Uvarov method and we obtain exact solutions for the energy levels and normalized wave functions. The interband optical absorption QDs of the parabolic spherical shape in GaAs is studied theoretically and the total optical absorption coefficient has been calculated by using the energy eigenvalues spectra and the corresponding wave functions.
关键词： quantum dots,threshold frequency of absorption,Aharonov–Bohm flux field,gravity,light interband transition,Parabolic harmonic oscillator,electromagnetic field
更新于2025-09-16 10:30:52
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Low-Light Image Enhancement with Semi-Decoupled Decomposition
摘要： Detection of defects in induction machine rotor bars for disassembled motors are required to evaluate machines considered for repair as well as fulfilling incremental quality assurance checks in the manufacture of new machines. Detection of rotor bar defects prior to motor assembly are critical in increasing repair efficiency and assuring the quality of newly manufactured machines. Many methods of detecting rotor bar defects in unassembled motors lack the sensitivity to find both major and minor defects in both cast and fabricated rotors along with additional deficiencies in quantifiable test results and arc-flash safety hazards. A process of direct magnetic field analysis can examine measurements from induced currents in a rotor separated from its stator yielding a high-resolution fingerprint of a rotor’s magnetic field. This process identifies both major and minor rotor bar defects in a repeatable and quantifiable manner appropriate for numerical evaluation without arc-flash safety hazards.
关键词： induction motors,ac motors,electromagnetic measurements,magnetic flux,AC machines,rotors
更新于2025-09-16 10:30:52
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Photovoltaic Module Fault Detection Using Integrated Magnetic Sensors
摘要： Fault detection and diagnosis of photovoltaic (PV) modules have become vital for reliable, efficient, and safe PV operating systems. This article proposes a new inspection method which is based on measuring the magnetic flux density on the surface of crystalline silicon PV modules. To measure the magnetic flux density generated around busbars of PV modules, their surfaces are scanned by two types of small integrated magnetic sensors for the one-dimensional (1-D) and 2-D magnetic profiles. This method enable us to detect different types of faults in PV modules, perform on-site measurements, and real time diagnosis. Since the measurement devices are composed of simple and small sensors, the overall cost of this method is very low as compared to other conventional fault detection methods.
关键词： photovoltaic (PV) module,Fault detection,magnetic flux density,magnetic sensor
更新于2025-09-12 10:27:22
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Controlled generation of chimera states in SQUID metasurfaces using DC flux gradients
摘要： SQUID (Superconducting QUantum Interference Device) metasurfaces, subject to a time-independent (dc) flux gradient and driven by a sinusoidal (ac) flux field, support chimera states that can be generated with zero initial conditions. The dc flux gradient and the amplitude of the ac flux can thus control the number of desynchronized clusters of such a generated chimera state (i.e., its “heads”) as well as their location and size. The combination of three measures, i.e., the synchronization parameter averaged over the period of the driving flux, the strength of incoherence, and the discontinuity measure, is used to predict the emergence or not of a chimera state and its multiplicity on the parameter plane of the dc flux gradient and the ac flux amplitude. Moreover, the full-width half-maximum of the distribution of the values of the synchronization parameter averaged over the period of the ac driving flux, allows to distinguish chimera states from non-chimera, partially synchronized states. Our findings are relevant from the pointview of both theory and applications. The SQUID oscillator provides an excellent physical example of systems with inertia and driving, for which chimera states have been under-examined. Finally, in the parameter regime under consideration, SQUID lattices are systems which are experimentally realisable and have very important applications in metamaterials science.
关键词： Flux gradient,SQUID Metasurfaces,Chimera states,Superconducting metamaterials
更新于2025-09-12 10:27:22
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Electromagnetically induced transparency and bound in continuum states in double Aharonov-Bohm coupled rings
摘要： We investigated electromagnetic induced transparency (EIT) resonances and bound in continuum (BIC) states in a simple mesoscopic structure made of double Aharonov-Bohm rings of lengths d1 and d2 threaded by a magnetic flux and coupled by a wire of length d0. These investigations are accomplished through an analysis of the amplitude of the transmission coefficient obtained using the Green’s function method. This structure may exhibit a large band gap and an EIT resonance in the transmission spectrum without introducing any impurity in one arm of the loop. In addition, we show that the shape of the EIT resonances and the width of the band gaps can be tuned by means of the magnetic flux and the geometry of the structure. These results may have important applications for electronic transport in mesoscopic systems.
关键词： Transmission spectrum,EIT resonance,Bound in continuum states,Aharonove-Bohm flux,Green’s function
更新于2025-09-12 10:27:22
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Hybrid spin-superconducting quantum circuit mediated by deterministically prepared entangled photonic states
摘要： In hybrid quantum systems, a controllable coupling can be obtained by mediating the interactions with dynamically introduced photons. We propose a hybrid quantum architecture consisting of two nitrogen vacancy center ensembles coupled to a tunable flux qubit, which is contained on the transmission line of a multimode nonlinear superconducting coplanar waveguide resonator with an appended Josephson mixing device. We discuss the use of entangled propagating microwaves photons, which through our nonlinear wave-mixing procedure are made into macroscopically distinct quantum states. We use these states to steer the system and show that, with further amplification, we can create a similar photonic state, which has a more distinct reduction of its uncertainty. Furthermore, we show that all of this leads to a lengthened coherence time, a reasonable fidelity that decays to 0.94 and then later increases upward to stabilize at 0.6, as well as a strengthened entanglement.
关键词： squeezed Schr?dinger cat state,entangled microwaves photons,Schr?dinger cat state,flux qubit,nitrogen vacancy center ensembles,superconducting coplanar waveguide resonator,hybrid quantum systems
更新于2025-09-12 10:27:22
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Enhancement of efficiency and CCT uniformity for red phosphor thin films, red LEDs and laminated white LEDs based on near-ultraviolet LEDs using MgO nanoparticles
摘要： Red phosphor thin films (PTFs) with different MgO nanoparticle concentrations for near-ultraviolet (NUV) LEDs were prepared based on their strong scattering effect; red LEDs and laminated white LEDs were packaged further. SEM and XRD showed that CaAlSiN3:Eu2+ (CASN) and MgO nanoparticles were uniformly distributed in silicone resin and their crystal structure remained unchanged. The phosphor conversion efficiency (PCE) had a maximum value of 83.15% when the MgO nanoparticle concentration was 15 wt%. An increase of concentration can improve the spatial distribution uniformity of photonics for 410 nm, 627 nm and 660 nm. Fluorescence lifetime showed that the value is positively correlated with concentration change. The packaged red LED luminous flux reaches a maximum of 20.337 lm at a concentration of 15 wt%. The laminated white LED showed that the MgO nanoparticle concentration can be used to adjust the correlated color temperature (CCT) from 4322 K to 1987 K. Under similar CCT, the red phosphor concentration is only 1.83 wt%, the dosage is reduced by 56.12%, and the corresponding luminous efficiency of radiation (LER) and luminous efficiency (LE) are 296.03 lm W-1 and 73.72 lm W-1 respectively. The increase was 11.42%, the decrease was 10.14%, the color rendering index (CRI) increased from 90.6 to 91.8, and CCT uniformity increased from 82.04% to 89.27% with an increase of 8.81%. Research shows that MgO nanoparticles have potential application value in the preparation of high-quality white LEDs.
关键词： MgO nanoparticles,phosphor conversion efficiency,NUV LEDs,luminous flux,CCT uniformity,red phosphor thin films
更新于2025-09-11 14:15:04