Results for "Q. Feng"

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A computational study of particle deposition patterns from a circular laminar jetAug 14 2016Sep 10 2016Particle deposition patterns on the plate of inertial impactor with circular laminar jet are investigated numerically with a Lagrangian solver implemented within the framework of the OpenFOAM$^{\circledR}$ CFD package. Effects of taper angle of the nozzle ... More
Diffusion-Controlled Quasi-Stationary Mass Transfer for an Isolated Spherical Particle in an Unbounded MediumDec 08 2011Sep 20 2012A consolidated mathematical formulation of the spherically symmetric mass-transfer problem is presented, with the quasi-stationary approximating equations derived from a perturbation point of view for the leading-order effect. For the diffusion-controlled ... More
A computational study of high-speed microdroplet impact onto a smooth solid surfaceFeb 18 2016Numerical solutions of high-speed microdroplet impact onto a smooth solid surface are computed, using the interFoam VoF solver of the OpenFOAM CFD package. Toward the solid surface, the liquid microdroplet is moving with an impinging gas flow, simulating ... More
Mist Flow Visualization for Round Jets in Aerosol Jet PrintingMay 23 2018Oct 06 2018With the microdroplets of water serving as light scattering particles, the mist flow patterns of round micro-jets can be visualized using the Aerosol Jet(R) direct-write system. The visualization images show that the laminar mist jet appears to extend ... More
Music in Terms of ScienceSep 17 2012To many people, music is a mystery. It is uniquely human, because no other species produces elaborate, well organized sound for no particular reason. It has been part of every known civilization on earth. It has become a very part of man's need to impose ... More
Small Interplanetary Magnetic Flux RopeMar 26 2019Small interplanetary magnetic flux ropes (SIMFRs) are often detected by space satellites in the interplanetary space near 1 AU. These ropes can be fitted by a cylindrically symmetric magnetic model. The durations of SIMFRsare usually <12 h, and the diameters ... More
A Note on the $k_T$-Factorization for Exclusive ProcessesMar 09 2011Jun 14 2011We show in detail that the $k_T$-factorization for exclusive processes is gauge-dependent and inconsistent.
Galactic Rotation Described with Thin-Disk Gravitational ModelMar 04 2008The measured rotation velocity profiles of mature spiral galaxies are successfully described with a gravitational model consisting of a thin axisymmetric disk of finte radius. The disk is assumed uniformly thin but with variable radial mass density. The ... More
Resummation of Large Logarithms in $γ^* π^0 \to γ$Apr 28 2007May 06 2007In the collinear factorization of the form factor for the transition $\gamma^* \pi^0 \to \gamma$ the hard part contains double log terms as $\ln^2 x$ with $x$ as the momentum fraction of partons from 0 to 1. A simple exponentiation for resummation leads ... More
Rotating thin-disk galaxies through the eyes of NewtonJul 22 2010Aug 16 2011By numerically solving the mass distribution in a rotating disk based on Newton's laws of motion and gravitation, we demonstrate that the observed flat rotation curves for most spiral galaxies correspond to exponentially decreasing mass density from galactic ... More
Galactic Rotation Described with Various Thin-Disk Gravitational ModelsApr 01 2008For mature spiral galaxies, the rotation velocities quickly increase from the galactic center and achieve a constant velocity from the core to the periphery. This dynamic behavior is described by models balancing Newtonian gravitational and centrifugal ... More
Activating Mg acceptors in AlN by oxygen: first principles calculationsSep 17 2007First principles calculations based on density functional theory (DFT) are performed to study the electronic properties of Mg acceptors in AlN at the presence of oxygen. It is found that Mg and O tend to form complexes like Mg-O, Mg$_2$-O, Mg$_3$-O and ... More
An isoperimetric inequality for eigenvalues of the bi-harmonic operatorJan 27 2011} In this article, we put forward a Neumann eigenvalue problem for the bi-harmonic operator $\Delta^2$ on a bounded smooth domain $\Om$ in the Euclidean $n$-space ${\bf R}^n$ ($n\ge2$) and then prove that the corresponding first non-zero eigenvalue $\Upsilon_1(\Om)$ ... More
Gauge Invariance and k_T-Factorization of Exclusive ProcessesJul 02 2008Feb 03 2009In the $k_T$-factorization for exclusive processes, the nontrivial $k_T$-dependence of perturbative coefficients, or hard parts, is obtained by taking off-shell partons. This brings up the question of whether the $k_T$-factorization is gauge invariant. ... More
Galactic Rotation Described with Bulge+Disk Gravitational ModelsApr 20 2008Observations reveal that mature spiral galaxies consist of stars, gases and plasma approximately distributed in a thin disk of circular shape, usually with a central bulge. The rotation velocities quickly increase from the galactic center and then achieve ... More
Spatiotemporal characteristics of the vertical structure of predictability and information transport in Northern HemisphereMay 04 2011Based on nonlinear prediction and information theory, vertical heterogeneity of predictability and information loss rate was obtained over the Northern Hemisphere. In seasonal to interannual time scales, the predictability is low in lower troposphere ... More
Cyclotron maser emission from power-law electrons with strong pitch-angle anisotropyMar 07 2016Energetic electrons with power-law spectrum are most commonly observed in astrophysics. This paper investigates electron cyclotron maser emission (ECME) from the power-law electrons, in which strong pitch-angle anisotropy is emphasized. The electron distribution ... More
Intrinsic Instability of Coronal StreamersJun 01 2009Plasma blobs are observed to be weak density enhancements as radially stretched structures emerging from the cusps of quiescent coronal streamers. In this paper, it is suggested that the formation of blobs is a consequence of an intrinsic instability ... More
Water vapor assisted sintering of silver nanoparticle inks for printed electronicsMar 09 2019In printed electronics, conductive traces are often produced by printing inks of silver nanoparticles dispersed in solvents. A sintering process is usually needed to make the printed inks conductive by removing the organic dispersants and allowing metal-to-metal ... More
Conservation laws of the generalized Riemann equations at $N=2,3,4$Sep 26 2016In this paper, we present infinitely many conserved densities satisfying particular conservation law $F_{t}=(2uF)_{x}$ for the generalized Riemann equations at $N=2,3,4$. In the $N=2$ case, we also construct conserved densities corresponding to new conservation ... More
Electric-Field Control of Magnetic Order: From FeRh to Topological Antiferromagnetic SpintronicsSep 17 2018Using an electric field instead of an electric current (or a magnetic field) to tailor the electronic properties of magnetic materials is promising for realizing ultralow energy-consuming memory devices because of the suppression of Joule heating, especially ... More
Power Control in Full Duplex Networks: Area Spectrum Efficiency and Energy EfficencyFeb 22 2017Full-duplex (FD) allows the exchange of data between nodes on the same temporal and spectrum resources, however, it introduces self interference (SI) and additional network interference compared to half-duplex (HD). Power control in the FD networks, which ... More
A magnetohydrodynamic model for multi-wavelength flares from Sagittarius~A$^\star$ (I): model and the near-infrared and X-ray flaresNov 09 2016Mar 15 2017Flares from the supermassive black hole in our Galaxy, Sagittarius~A$^\star$ (Sgr A$^\star$), are routinely observed over the last decade or so. Despite numerous observational and theoretical efforts, the nature of such flares still remains poorly understood, ... More
Topological quantum phase transition in an extended Kitaev spin modelFeb 02 2009Feb 08 2009We study the quantum phase transition between Abelian and non-Abelian phases in an extended Kitaev spin model on the honeycomb lattice, where the periodic boundary condition is applied by placing the lattice on a torus. Our analytical results show that ... More
Exotic phase diagram of a topological quantum systemJul 23 2010Nov 14 2010We study the quantum phase transitions (QPTs) in the Kitaev spin model on a triangle-honeycomb lattice. In addition to the ordinary topological QPTs between Abelian and non-Abelian phases, we find new QPTs which can occur between two phases belonging ... More
Topological states and braiding statistics using quantum circuitsAug 30 2008Using superconducting quantum circuits, we propose an approach to construct a Kitaev lattice, i.e., an anisotropic spin model on a honeycomb lattice with three types of nearest-neighbor interactions. We study two particular cases to demonstrate topological ... More
Multi-waveband polarimetric observations of NRAO 530 on parsec-scaleJun 16 2010We report on multi-bands VLBA polarimetric observations of NRAO 530 in February 1997. Total intensity, EVPA distributions at all these frequencies are presented. Model fitting has been performed, from which the fitted southmost component A is confirmed ... More
Remote-control spin filtering through a $T$-type structureOct 05 2006Mar 01 2007We propose a spin filter scheme using a $T$-stub waveguide. By applying a moderate magnetic field at the tip of the sidearm, this device can produce both large electric and spin current. The direction, polarization of the output spin current can be further ... More
Anomalous c-axis charge dynamics in copper oxide materialsJun 17 1999Nov 06 2003Within the t-J model, the c-axis charge dynamics of the copper oxide materials in the underdoped and optimally doped regimes is studied by considering the incoherent interlayer hopping. It is shown that the c-axis charge dynamics is mainly governed by ... More
Confronting the jet model of Sgr A* with the Faraday rotation measure observationsOct 22 2014Sgr A* is probably the supermassive black hole being investigated most extensively due to its proximity. Several theoretical models for its steady state emission have been proposed in the past two decades. Both the radiative-inefficient accretion flow ... More
On the generation mechanism of electromagnetic cyclotron waves in the solar wind: statistical results from Wind observationsDec 13 2018Electromagnetic cyclotron waves (ECWs) near the proton cyclotron frequency are frequently observed in the solar wind, yet their generation mechanism is still an open question. Based on the Wind data during the years 2005$-$2015, this paper carries out ... More
Charge dynamics in doped triangular antiferromagnetsApr 10 2000Within the framework of the fermion-spin theory based on the charge-spin separation, the charge dynamics of the doped antiferromagnet on a triangular lattice is studied. The holon part is treated by using the loop expansion to the second order. It is ... More
The effect of electron holes on cyclotron maser emission driven by horseshoe distributionsNov 07 2016This Brief Communication presents a quantitative investigation for the effect of electron holes on electron-cyclotron maser (ECM) driven by horseshoe distributions. The investigation is based on an integrated distribution function for the horseshoe distributions ... More
Temporal and Spectral Properties of Gamma-Ray FlashesFeb 05 2002The temporal and spectral properties of terrestrial gamma-ray flashes (TGFs) are studied. The delay of low energy photons relative to high energy ones in the gamma-ray variations of the TGFs with high signal to noise ratio has been revealed by an approach ... More
Design of Prototype Front-end Digital Module for Direct Dark Matter Detection based on LArJun 25 2018Liquid argon (LAr) with a high light yield of approximately 40 photons per keV is an attractive target for the direct detection of weakly interacting massive particles (WIMPs), which are well motivated galactic dark matter candidates. We studies a front-end ... More
Non-iterative recomputation of dense layers for performance improvement of DCNNSep 14 2018An iterative method of learning has become a paradigm for training deep convolutional neural networks (DCNN). However, utilizing a non-iterative learning strategy can accelerate the training process of the DCNN and surprisingly such approach has been ... More
Quantum emulation of a spin system with topologically protected ground states using superconducting quantum circuitsDec 03 2009Using superconducting quantum circuit elements, we propose an approach to experimentally construct a Kitaev lattice, which is an anisotropic spin model on a honeycomb lattice with three types of nearest-neighbor interactions and having topologically protected ... More
$QQ^{\prime} \bar u \bar d$ bound state in the Bethe-Salpeter equation approachSep 30 2013In the heavy quark limit, we establish the Bethe-Salpeter equations for the ground state $QQ^{\prime} \bar u \bar d$ containing one heavy diquark $QQ^{\prime}$ ($Q, Q^{\prime}=b$ or $c$) and one light antidiquark $\bar u \bar d$. We solve the Bethe-Salpeter ... More
Suppression of Stimulated Raman Scattering and Hot Electrons Generation due to Langmuir Decay Instability Cascade and Langmuir CollapseDec 05 2016Backward stimulated Raman scattering (BSRS) with Langmuir decay instability (LDI) and Langmuir collapse has been researched by Vlasov simulation for the first time. The decay productions of LDI cascade and their evolution with time is clearly demonstrated, ... More
Fluid nonlinear frequency shift of nonlinear ion acoustic waves in multi-ion species plasmas in small wave number regionAug 12 2016The properties of the nonlinear frequency shift (NFS) especially the fluid NFS from the harmonic generation of the ion-acoustic wave (IAW) in multi-ion species plasmas have been researched by Vlasov simulation. The pictures of the nonlinear frequency ... More
Stimulated Brillouin scattering behaviors in different species ignition hohlraum plasmas in high-temperature and high-density regionApr 05 2017The presence of multiple ion species can add additional branches to the IAW dispersion relation and change the Landau damping significantly. Different IAW modes excited by stimulated Brillouin scattering (SBS) and different SBS behaviors in several typical ... More
Harmonics Effect on Ion-Bulk Waves in CH PlasmasSep 08 2016The harmonics effect on ion-bulk (IBk) waves has been researched by Vlasov simulation. The condition of excitation of a large-amplitude IBk waves is given to explain the phenomenon of strong short-wavelength electrostatic activity in solar wind. When ... More
Streamer Wave Events Observed in Solar Cycle 23May 22 2011In this paper we conduct a data survey searching for well-defined streamer wave events observed by the Large Angle and Spectrometric Coronagraph (LASCO) on-board the Solar and Heliospheric Observatory (SOHO) throughout Solar Cycle 23. As a result, 8 candidate ... More
Radio signatures of CME-streamer interaction and source diagnostics of type II radio burstApr 25 2012It has been suggested that type II radio bursts are due to energetic electrons accelerated at coronal shocks. Radio observations, however, have poor or no spatial resolutions to pinpoint the exact acceleration locations of these electrons. In this paper, ... More
Possible cool prominence materials detected within interplanetary small magnetic flux ropesMar 27 2019Previous studies indicate that interplanetary small magnetic flux ropes (SMFRs) are manifestations of microflare-associated small coronal mass ejections (CMEs), and the hot material with high charge states heated by related microflares are found in SMFRs. ... More
31 Glitches in Twelve Radio PulsarsJun 06 2018Jun 14 2018Data are gathered from the Parkes pulsar data archive of twelve young radio pulsars, with the intervals of data for each pulsar ranged between 2.8 years and 6.8 years. 31 glitches are identified by using phase connection from "pulsar timing" technology, ... More
Excitation of nonlinear ion acoustic waves in CH plasmasJul 22 2016Excitation of nonlinear ion acoustic wave (IAW) by an external electric field is demonstrated by Vlasov simulation. The frequency calculated by the dispersion relation with no damping is verified much closer to the resonance frequency of the small-amplitude ... More
Effect of thermal ions on fluid nonlinear frequency shift of ion acoustic waves in multi-ion species plasmasJun 24 2019A model of the fluid nonlinear frequency shift of ion acoustic waves (IAWs) in multi-ion species plasmas is presented, which considers the effect of ion temperature. Because the thermal ion exists in plasmas in inertial confinement fusion (ICF) and also ... More
Diagnostics on the source properties of type II radio burst with spectral bumpsMar 06 2013In recent studies (Feng et al., 2012; Kong et al., 2012), we proposed that source properties of type II radio bursts can be inferred through a causal relationship between the special shape of the type II dynamic spectrum (e.g., bump or break) and simultaneous ... More
Vapor Transport of a Volatile Solvent for a Multicomponent Aerosol DropletJul 19 2015This work presents analytical formulas derived for evaluating vapor transport of a volatile solvent for an isolated multicomponent droplet in a quiescent environment, based on quasi-steady-state approximation. Among multiple solvent components, only one ... More
Micropipette aspiration method for characterizing biological materials with surface energyJan 11 2018Many soft biological tissues possess a considerable surface stress, which plays a significant role in their biophysical functions, but most previous methods for characterizing their mechanical properties have neglected the effects of surface stress. In ... More
Multi-Frequency VLBI Observations of NRAO 530May 23 2006We report on VLBA observations of a gamma-ray bright blazar NRAO 530 at multiple frequencies (5, 8, 15, 22, 39, 43, and 45 GHz) in 1997 and 1999. These multi-epoch multi-frequency high-resolution VLBI images exhibit a consistent core-dominated morphology ... More
Quasi-Periodic Releases of Streamer Blobs and Velocity Variability of the Slow Solar Wind near the SunJul 05 2009We search for persistent and quasi-periodic release events of streamer blobs during 2007 with the Large Angle Spectrometric Coronagraph on the \textit{Solar and Heliospheric Observatory} and assess the velocity of the slow solar wind along the plasma ... More
Electron Electric Dipole Moment in Mirror Fermion Model with Electroweak Scale Non-sterile Right-handed NeutrinosFeb 15 2017Jan 13 2018The electric dipole moment of the electron is studied in detail in an extended mirror fermion model with the following unique features of (a) right-handed neutrinos are non-sterile and have masses at the electroweak scale, and (b) a horizontal symmetry ... More
Burst behavior due to quasimode excited by stimulated Brillouin scattering in high-intensity laser-plasma interactionJun 24 2019The strong-coupling mode, called quasimode, will be excited by stimulated Brillouin scattering (SBS) in high-intensity laser-plasma interaction. And SBS of quasimode will compete with SBS of fast mode (or slow mode) in multi-ion species plasmas, thus ... More
Possible Nodeless Superconducting Gaps in Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ and YBa$_2$Cu$_3$O$_{7-x}$ Revealed by Cross-Sectional Scanning Tunneling SpectroscopyNov 14 2016Pairing in the cuprate high-temperature superconductors and its origin remain among the most enduring mysteries in condensed matter physics. With cross-sectional scanning tunneling microscopy/ spectroscopy, we clearly reveal the spatial-dependence or ... More
Effects of tensor and $T=0$ pairing interactions on nuclear $β^+$/EC decayOct 04 2017The Hartree-Fock-Bogolyubov (HFB) plus proton-neutron quasiparticle random phase approximation (pnQRPA) approach based on Skyrme interaction is applied to study the nuclear $\beta^+$/EC decay for nuclei near the proton magic numbers $Z=$20, 28, and 50. ... More
Are Infrared Dark Clouds Really Quiescent?Mar 15 2016Jul 30 2016The dense, cold regions where high-mass stars form are poorly characterised, yet they represent an ideal opportunity to learn more about the initial conditions of high-mass star formation (HMSF), since high-mass starless cores (HMSCs) lack the violent ... More
Morphological evolution of a 3D CME cloud reconstructed from three viewpointsMar 15 2012The propagation properties of coronal mass ejections (CMEs) are crucial to predict its geomagnetic effect. A newly developed three dimensional (3D) mask fitting reconstruction method using coronagraph images from three viewpoints has been described and ... More
An imaging study of a complex solar coronal radio eruptionJul 30 2016Solar coronal radio bursts are enhanced radio emission excited by energetic electrons accelerated during solar eruptions, studies on which are important for investigating the origin and physical mechanism of energetic particles and further diagnosing ... More
Perfect spin-fillter and spin-valve in carbon atomic chainsNov 01 2009We report ab initio calculations of spin-dependent transport in single atomic carbon chains bridging two zigzag graphene nanoribbon electrodes. Our calculations show that carbon atomic chains coupled to graphene electrodes are perfect spin-filters with ... More
A novel two-mode squeezed light based on double-pump phase-matchingFeb 27 2019May 16 2019A novel two-mode non-degenerate squeezed light is generated based on a four-wave mixing (4WM) process driven by two pump fields crossing at a small angle. By exchanging the roles of the pump beams and the probe and conjugate beams, we have demonstrated ... More
Start-to-end simulation of the injector for a compact THz sourceOct 29 2013Terahertz radiation has broad application prospect due to its ability to penetrate deep into many organic materials without damage caused by ionizing radiations. A FEL-based THz source is the best choice to produce high-power radiation. In this paper, ... More
Fe-based high temperature superconductivity with Tc=31K bordering an insulating antiferromagnet in (Tl,K)FexSe2 CrystalsDec 23 2010Up to now, there have been two material families, the cuprates and the iron-based compounds with high-temperature superconductivity (HTSC). An essential open question is whether the two classes of materials share the same essential physics. In both, superconductivity ... More
Particle kinetic analysis of a polar jet from SECCHI COR dataDec 10 2011Aims. We analyze coronagraph observations of a polar jet observed by the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument suite onboard the Solar TErrestrial RElations Observatory (STEREO) spacecraft. Methods. In our analysis ... More
Anomalous magnetic and electric moments of $τ$ and lepton flavor mixing matrix in effective lagrangian approachMay 28 2002Jun 17 2002In an effective lagrangian approach [EM97] to new physics, the authors in ref. [HL99] pushed tau anomalous magnetic and electric dipole moments (AMDM and EDM) down to $10^{-11}$ and $10^{-25} e cm$ by using a Fritzsch-Xing lepton mass matrix ansatz. In ... More
Implementation of many-qubit Grover search by cavity QEDAug 21 2008Oct 07 2008We study the possibility of an implementation of N-qubit (N>3) Grover search in cavity QED, based on a fast operation of N-qubit controlled phase-flip with atoms in resonance with the cavity mode. We demonstrate both analytically and numerically that, ... More
Exploiting Trust Degree for Multiple-Antenna User CooperationMay 10 2017For a user cooperation system with multiple antennas, we consider a trust degree based cooperation techniques to explore the influence of the trustworthiness between users on the communication systems. For the system with two communication pairs, when ... More
Existence problem of proton semi-bubble structure in the $2_1^+$ state of $^{34}$SiApr 20 2017The fully self-consistent Hartree-Fock (HF) plus random phase approximation (RPA) based on Skyrme-type interaction is used to study the existence problem of proton semi-bubble structure in the $2_1^+$ state of $^{34}$Si. The experimental excitation energy ... More
Thermal transport due to quantum interference in magnetic tunnel junctionsAug 21 2013We study the thermal transport in magnetic tunnel junctions. Thermal gradients across the tunneling barrier appear around the Fowler-Nordheim tunneling regime, due to the current-induced heat caused by quantum interference. Both thermovoltage and thermal ... More
High-performance Raman quantum memory with optimal controlApr 28 2018Quantum memories with high efficiency and fidelity are essential for long-distance quantum communication and information processing. Techniques have been developed for quantum memories based on atomic ensembles. The atomic memories relying on the atom-light ... More
Superthermal electron generation by two-stage acceleration of backward and forward stimulated Raman scattering in high electron density regionJun 24 2019The mechanism of two-stage electron acceleration by backward stimulated Raman scattering (BSRS) and forward stimulated Raman scattering (FSRS) is demonstrated through relativistic Vlasov-Maxwell simulation. The theoretical model is given to judge the ... More
Charge Transfer Effects in Naturally Occurring van der Waals Heterostructures (PbSe)1.16(TiSe2)m (m=1, 2)Mar 10 2018Van der Waals heterostructures (VDWHs) exhibit rich properties and thus has potential for applications, and charge transfer between different layers in a heterostructure often dominates its properties and device performance. It is thus critical to reveal ... More
Radiative deflection by spin effect in the quantum radiation-reaction regimeJan 30 2019The colliding between ultra-relativistic electrons and an ultra-intense laser pulse is a powerful approach to testify the physics in strong-field QED regime. By considering spin-dependent radiation-reaction during laser-electron collision we find anti-symmetric ... More
High-resolution inelastic X-ray scattering studies of the state-resolved differential cross-section of Compton excitations in helium atomsJun 17 2009The state-resolved differential cross sections for both the 1s2 1S0 - 1s2s 1S0 monopolar transition and the 1s2 1S0 - 1s2p 1P1 dipolar transition of atomic helium have been measured over a large momentum transfer region by the high-resolution inelastic ... More
Scanning tunneling microscopy study of the possible topological surface states in BiTeClFeb 25 2015Recently, the non-centrosymmetric bismuth tellurohalides such as BiTeCl are being studied as possible candidates of topological insulators. While some photoemission studies showed that BiTeCl is an inversion asymmetric topological insulator, others showed ... More
Anisotropic but nodeless superconducting gap in the presence of spin density wave in iron-pnictide superconductor NaFe1-xCoxAsSep 10 2012Jan 04 2013The coexisting regime of spin density wave (SDW) and superconductivity in the iron pnictides represents a novel ground state. We have performed high resolution angle-resolved photoemission measurements on NaFe1-xCoxAs (x = 0.0175) in this regime and revealed ... More
Observation of novel gapped phases in potassium doped single layer p-terphenyl on Au (111)May 28 2017Recently, superconductivity in potassium (K) doped p-terphenyl (C18H14) has been suggested by the possible observation of the Meissner effect and subsequent photoemission spectroscopy measurements, but the detailed lattice structure and more-direct evidence ... More
The distinct in-plane resistivity anisotropy in the nematic states of detwinned NaFeAs and FeTe single crystals: evidences for Hund's rule metalOct 01 2012The in-plane resistivity anisotropy has been studied with the Montgomery method on two detwinned parent compounds of the iron-based superconductors, NaFeAs and FeTe. For NaFeAs, the resistivity in the antiferromagnetic (AFM) direction is smaller than ... More
Phosphor induced significant hole-doping in ferropnictide superconductor BaFe2(As(1-x)Px)2May 26 2011The superconductivity in high temperature superconductors ordinarily arises when doped with hetero-valent ions that introduce charge carriers. However, in ferropnictides, "iso-valent" doping, which is generally believed not to introduce charge carriers, ... More
Angle-resolved photoemission evidence of s-wave superconducting gap in KxFe2-ySe2 superconductorMay 03 2012Although nodeless superconducting gap has been observed on the large Fermi pockets around the zone corner in KxFe2-ySe2, whether its pairing symmetry is s-wave or nodeless d-wave is still under intense debate. Here we report an isotropic superconducting ... More
Observation of Dirac Cone Band Dispersion in FeSe Thin Films by Photoemission SpectroscopyAug 29 2015The electronic structure of FeSe thin films grown on SrTiO3 substrate is studied by angle-resolved photoemission spectroscopy (ARPES). We reveal the existence of Dirac cone band dispersions in FeSe thin films thicker than 1 Unit Cell below the nematic ... More
Bismuth-content dependent of the polarized Raman spectra of the InPBi alloysDec 15 2015We have systematically investigated the optical properties of the InP1-xBix ternary alloys with 0<x<2.46%, using high resolution polarized Raman scattering measurement. Both InP-like and InBi-like optical vibration modes (LO) were identified in all the ... More
Monte Carlo Calculation of Exposure Profiles and Greeks for Bermudan and Barrier Options under the Heston Hull-White ModelDec 11 2014Valuation of Credit Valuation Adjustment (CVA) has become an important field as its calculation is required in Basel III, issued in 2010, in the wake of the credit crisis. Exposure, which is defined as the potential future loss of a default event without ... More
Ion-crystal demonstration of structural phase transition induced solely by temperatureDec 11 2018We demonstrate for the first time a linear-zigzag phase transition induced solely by temperature of the $^{40}$Ca$^{+}$ ion crystals in a surface-electrode trap. In contrast to the previously observed counterparts based on change of the mechanical equilibrium ... More
Direct evidence of superconductivity and determination of the superfluid density in buried ultrathin FeSe grown on SrTiO$_3$Feb 08 2016Jan 15 2018Bulk FeSe is superconducting with a critical temperature $T_c$ $\cong$ 8 K and SrTiO$_3$ is insulating in nature, yet high-temperature superconductivity has been reported at the interface between a single-layer FeSe and SrTiO$_3$. Angle resolved photoemission ... More
Detection of a Compact Nuclear Radio Source in the Local Group Elliptical Galaxy M32Feb 11 2015Jun 12 2015The Local Group compact elliptical galaxy M32 hosts one of the nearest candidate super-massive black holes (SMBHs), which has a previously suggested X-ray counterpart. Based on sensitive observations taken with the {\it Karl G. Jansky} Very Large Array ... More
A coronal seismological study with streamer wavesDec 23 2010We present a novel method to evaluate the Alfven speed and the magnetic field strength along the streamer plasma sheet in the outer corona. The method is based on recent observations of streamer waves, which are regarded as the fast kink body mode carried ... More
Nonadiabatic holonomic quantum computation with dressed-state qubitsDec 12 2016May 24 2017Implementing holonomic quantum computation is a challenging task as it requires complicated interaction among multilevel systems. Here we propose to implement nonadiabatic holonomic quantum computation based on dressed-state qubits in circuit QED. An ... More
Giant H II Regions in M101. I. X-ray Analysis of Hot GasOct 07 2012We performed a Chandra X-ray study of three giant H II regions (GHRs), NGC 5461, NGC 5462, and NGC 5471, in the spiral galaxy M101. The X-ray spectra of the three GHRs all contain a prominent thermal component with a temperature of ~0.2 keV. In NGC 5461, ... More
Superconductivity at 32K and anisotropy in Tl0.58Rb0.42Fe1.72Se2 crystalsJan 03 2011Single crystals of Tl0.58Rb0.42Fe1.72Se2 are successfully grown with the superconducting transition temperatures Tconset=32K and Tczero=31.4K. The Hall coefficient exhibits a multi-band behavior, which is very similar to that of all other Fe-based superconductors. ... More
Online aging study of high rate MRPCAug 14 2015Sep 06 2015With the constant increase of accelerator luminosity, the rate requirements of the MRPC detectors become important. In the same time, aging problem of the detector has to be studied meticulously. An online aging test system is set up in our Lab. The setup ... More
Ferromagnetism in 2p Light Element-Doped II-oxide and III-nitride SemiconductorsSep 13 2007II-oxide and III-nitride semiconductors doped by nonmagnetic 2p light elements are investigated as potential dilute magnetic semiconductors (DMS). Based on our first-principle calculations, nitrogen doped ZnO, carbon doped ZnO, and carbon doped AlN are ... More
Intense source of cold cesium atoms based on a two-dimensional magneto-optical trap with independent axial cooling and pushingSep 24 2015We report our studies on an intense source of cold cesium atoms based on a two-dimensional magneto-optical trap with independent axial cooling and pushing. The new-designed source, proposed as 2D-HP MOT, uses hollow laser beams for axial cooling and a ... More
The weak electronic correlations and absence of heavy Fermion state in KNi$_2$Se$_2$Nov 24 2014We have studied the low-lying electronic structure of a new ThCr$_2$Si$_2$-type superconductor KNi$_2$Se$_2$ with angle-resolved photoemission spectroscopy. Three bands intersect the Fermi level, forming complicated Fermi surface topology, which is sharply ... More
The unique electronic structure of Ca10(Pt4As8)(Fe2-xPtxAs2)5 with metallic Pt4As8 layersAug 13 2013We studied the low-lying electronic structure of the newly discovered iron-platinum-arsenide superconductor, Ca10(Pt4As8)(Fe2-xPtxAs2)5 (Tc=22 K) with angle-resolved photoemission spectroscopy. We found that the Pt4As8 layer contributes to a small electron-like ... More
Orbital selective correlations between nesting/scattering/Lifshitz transition and the superconductivity in AFe1-xCoxAs (A=Li, Na)Mar 04 2013Apr 29 2014The correlations between the superconductivity in iron pnictides and their electronic structures are elusive and controversial so far. Here through angle-resolved photoemission spectroscopy measurements, we show that such correlations are rather distinct ... More
New prototype scintillator detector for the Tibet AS$γ$ ExperimentDec 18 2017The hybrid Tibet AS array was successfully constructed in 2014. It has 4500 m$^{2}$ underground water Cherenkov pools used as the muon detector (MD) and 789 scintillator detectors covering 36900 m$^{2}$ as the surface array. At 100 TeV, cosmic-ray background ... More
BES3 time of flight monitoring systemApr 27 2008A Time of Flight monitoring system has been developed for BES3. The light source is a 442-443 nm laser diode, which is stable and provides a pulse width as narrow as 50 ps and a peak power as large as 2.6 W. Two optical-fiber bundles with a total of 512 ... More
The radio counter-jet of the QSO 3C~48Dec 20 2004We present multi--frequency radio observational results of the quasar 3C~48. The observations were carried out with the Very Large Array (VLA) at five frequencies of 0.33, 1.5, 4.8, 8.4, and 22.5 GHz, and with the Multi--Element Radio Linked Interferometer ... More