查看更多>>摘要:The main goal of our study is to reveal unexpected but intriguing analogies arising between optical solitons and nuclear physics,which still remain hidden from us.We consider the main cornerstones of the concept of nonlinear optics of nuclear reactions and the well-dressed repulsive-core solitons.On the base of this model,we reveal the most intriguing properties of the nonlinear tunneling of nucleus-like solitons and the soliton self-induced sub-barrier transparency effect.We describe novel interesting and stimulating analogies between the interaction of nucleus-like solitons on the repulsive barrier and nuclear sub-barrier reactions.The main finding of this study concerns the conservation of total number of nucleons(or the baryon number)in nuclear-like soliton reactions.We show that inelastic interactions among well-dressed repulsive-core solitons arise only when a"cloud"of"dressing"spectral side-bands appears in the frequency spectra of the solitons.This property of nucleus-like solitons is directly related to the nuclear density distribution described by the dimensionless small shape-squareness parameter.Thus the Fourier spectra of nucleus-like solitons are similar to the nuclear form factors.We show that the nuclear-like reactions between well-dressed solitons are realized by"exchange"between"particle-like"side bands in their spectra.
查看更多>>摘要:We review the predictions of quark models for multiquark configurations that are bound or resonant states,and compare different methods for estimating the properties of resonances.
查看更多>>摘要:Recently,a new excited baryon state,Ω(2012),was observed in the invariant mass spectra of K-Ξ0 and K0SΞ-by the Belle collaboration.This state has a narrow width(~6MeV)compared to other baryon states with a similar mass.Here,we provide a mini-review on the Ω(2012)state from the molecular perspective,where it appears to be a dynamically generated state with spin-parity 3/2-from the coupled-channels interactions of the KΞ(1530)and ηΩ in s-wave and KΞ in d-wave.Additionally,alternative explanations for the Ω(2012)resonance are also discussed.
查看更多>>摘要:Terahertz heterodyne receivers with high sensitivity and spectral resolution are crucial for various applications.Here,we present a room-temperature atomic terahertz heterodyne receiver that achieves ultrahigh sensitivity and frequency resolution.At a signal frequency of 338.7 GHz,we obtain a sensitivity of 2.88±0.09 µV·cm-1·Hz-1/2 for electric field measurements.The calibrated linear dynamical range spans approximately 89 dB,ranging from-110dBV/cm to-21dBV/cm.We demodulate a 400 symbol stream encoded in 4-state phase-shift keying,demonstrating excellent phase detection capability.By scanning the frequency of the local oscillator,we realize a terahertz spectrometer with Hz level frequency resolution.This resolution is more than two orders of mag-nitude higher than that of existing terahertz spectrometers.The demonstrated terahertz heterodyne receiver holds promising potential for working across the entire terahertz spectrum,significantly advancing its practical applications.
查看更多>>摘要:Our primary objective is to mitigate the adverse effects of temperature fluctuations on the optical frequency transmission system by reducing the length of the interferometer.Following optimization,the phase-temperature coefficient of the optical system is reduced to approximately 1.35 fs/K.By applying a sophisticated temperature control to the remained"out-of-loop"optics fiber,the noise floor of the system has been effectively lowered to 10-21 level.Based on this performance-enhanced transfer system,we demonstrate coherent transmission of optical frequency through 500-km spooled fiber link.After being actively compensated,the transfer instability of 4.5 × 10-16 at the averaging time of 1s and 5.6 × 10-21 at 10000s is demonstrated.The frequency uncertainty of received light at remote site relative to that of the origin light at local site is achieved to be 1.15 × 10-19.This enhanced system configuration is particularly well suited for future long-distance frequency transmission and comparison of the most advanced optical clock signals.
查看更多>>摘要:The carbon black(CB)is introduced to manufacture CB/graphene oxide(GO)composite material to mitigate limitations of GO as a saturable absorber with the excellent performance in ultrafast fiber lasers.At a central wavelength of 1555.5 nm,the stable mode-locked pulse with width of 656 fs,repetition rate of 20.16 MHz,and high signal-to-noise ratio of 82.07dB is experimentally obtained.Additionally,experimental observations for pulsation phenomena of vector biperiodic solitons combining period-1 and period-17,period-2 and period-32,period-3 and period-36 are verified via simulations.
查看更多>>摘要:The outstanding issue to overcoming atmospheric turbulence on distant imaging is a fundamental interest and technological challenge.We propose a novel scenario and technique to restore the optical image in turbulent environmental by referring to Cyclopean image with binocular vision.With human visual intelligence,image distortion resulting from the turbulence is shown to be substantially suppressed.Numerical simulation results taking into account of the atmospheric turbulence,optical image system,image sensors,display and binocular vision perception are presented to demonstrate the robustness of the image restoration,which is compared with a single channel planar optical imaging and sensing.Experiment involving binocular telescope,image recording and the stereo-image display is conducted and good agreement is obtained between the simulation with perceptive experience.A natural extension of the scenario is to enhance the capability of anti-vibration or anti-shaking for general optical imaging with Cyclopean image.
查看更多>>摘要:Tokamak plasmas with elongated cross sections are susceptible to vertical displacement events(VDEs),which can damage the first wall via heat flux or electromagnetic(EM)forces.We present a 3D nonlinear reduced magnetohydrodynamic(MHD)simulation of CFETR plasma during a cold VDE following the thermal quench,focusing on the relationship among the EM force,plasma displacement,and the n=1 mode.The dominant mode,identified as m/n=2/1,becomes destabilized when most of the current is contracted within the q=2 surface.The displacement of the plasma current centroid is less than that of the magnetic axis due to the presence of SOL current in the open field line region.Hence,the symmetric component of the induced vacuum vessel current is significantly mitigated.The direction of the sideways force keeps a constant phase approximately compared to the asymmetric component of the vacuum vessel current and the SOL current,which in turn keep in-phase with the dominant 2/1 mode.Their amplitudes are also closely associated with the growth of the dominant mode.These findings provide insights into potential methods for controlling the phase and amplitude of sideways forces during VDEs in the future.
查看更多>>摘要:For warm/hot and dense plasmas(WDPs),ionization potential depression(IPD)plays a crucial role in determining its ionization balance and understanding the resultant microscopic plasma properties.A sophisticated and unified IPD model is necessary to resolve those existing discrepancies between theoretical and experimental results.However,the applicability of those widely used IPD models nowadays is limited,especially for the nonlocal thermodynamic equilibrium(non-LTE)dense plasma produced by short-pulse laser.In this work,we propose an IPD model that considers inelastic atomic processes,in which three-body recombination and collision ionization processes are found to play a crucial role in determining the electron distribution and IPD for a WDP.This IPD model is validated by reproducing latest experimental results of Al plasmas with a wide-range condition of 70 eV-700 eV temperature and 0.2-3 times solid density,as well as a typical non-LTE system of hollow Al ions.It is demonstrated that the present IPD model has a significant temperature dependence due to the consideration of the inelastic collision processes.With a lower computational cost and wider application range of plasma conditions,the proposed model is expected to provide a promising tool to study the ionization balance and the atomic processes,as well as the related radiation and particle transports properties of the WDP.
查看更多>>摘要:We study the desorption mechanism of hydrogen isotopes from graphene surface using first-principles calcula-tions,with focus on the effects of quantum tunneling.At low temperatures,quantum tunneling plays a dominant role in the desorption process of both hydrogen monomers and dimers.In the case of dimer desorption,two types of mechanisms,namely the traditional one-step desorption in the form of molecules(molecular mechanism),and the two-step desorption in the form of individual atoms(atomic mechanism),are studied and compared.For the ortho-dimers,the dominant desorption mechanism is found to switch from the molecular mechanism to the atomic mechanism above a critical temperature,which is~300K and 200 K for H and D,respectively.