Out-of-Plane Torque Influence on Magnetization Switching and Susceptibility in Magnetic Multilayers

Based on both the spin diffusion equation and the Landau-LlTshitz-Gilbert （LLG） equation, we demonstrate the influence of out-of-plane spin torque on magnetization switching and susceptibility in a magnetic multilayer system. The variation of spin accumulation and local magnetization with respect to time are studied in the magnetization reversal induced by spin torque. We also research the susceptibility subject to a microwave magnetic field, which is compared with the results obtained without out-of-plane torque.     

Structures of NΩ and △Ω Dibaryons

We study the structures of NΩ and △Ω systems in the extended chiral SU（3） quark model by solving a resonating group method equation. The results show that both systems are weakly bound states and changed into unbound states if we consider the mixing of scalar mesons.     

Sub-diffusive scaling with power-law trapping times

Thermally driven diffusive motion of a particle underlies many physical and biological processes. In the presence of traps and obstacles, the spread of the particle is substantially impeded, leading to subdiffusive scaling at long times.The statistical mechanical treatment of diffusion in a disordered environment is often quite involved. In this short review,we present a simple and unified view of the many quantitative results on anomalous diffusion in the literature, including the scaling of the diffusion front and the mean first-passage time. Various analytic calculations and physical arguments are examined to highlight the role of dimensionality, energy landscape, and rare events in affecting the particle trajectory statistics. The general understanding that emerges will aid the interpretation of relevant experimental and simulation results.     

Evolution of Matter Wave Interference of Bose-Condensed Gas in a 1D Optical Lattice

For a Bose-condensed gas in a combined potential consisting of an axially-symmetric harmonic magnetic trap and one-dimensional （1D） optical lattice, using the mean-field Gross-Pitaevskii （G-P） equation and the propagator method, we obtain the analytical result of the order parameter for matter wave interference at any time. The evolution of the interference pattern under a variation of the relative phase △Ф between successive subcondensates trapped on an optical lattices is also studied. For △Ф=π, the interference pattern is symmetric with two sharp peaks, which are symmetrically located on a straight line on both sides of a vacant central peak and moving apart from each other. This work is in agreement with available experimental results.     

Atomic diffusion across NisoTiso-Cu explosive welding interface： Diffusion layer thickness and atomic concentration distribution

Molecular dynamics simulations are carried out to study atomic diffusion in the explosive welding process of NisoTis0-Cu （at.%）. By using a hybrid method which combines molecular dynamics simulation and classical diffusion the- ory, the thickness of the diffusion layer and the atomic concentration distribution across the welding interface are obtained. The results indicate that the concentration distribution curves at different times have a geometric similarity. According to the geometric similarity, the atomic concentration distribution at any time in explosive welding can be calculated. NisoTis0- Cu explosive welding and scanning electron microscope experiments are done to verify the results. The simulation results and the experimental results are in good agreement.     

Theoretical and experimental study of the intensity distribution in biological tissues

Based on the diffusion approximate theory （DA）, a theoretical model about the distribution of the intensity of a narrow collimation beam illuminating on a semi-lnfinite biological tissue is developed. In order to verify the correctness of the model, a novel method of measuring the distributions of the intensity of light in Intralipid-10% suspension at 650 nm is presented and ts of the distributions of the distance-dependent intensity of scattering light in different directions are made. The investigations show that the results from our diffusion model are in good agreement with the experimental results beyond and in the areas around the light source, and the distance-dependent intensity in the incident direction attenuates approximately in the exponential form. Furthermore, our theoretic results indicate the anisotropic characteristics of the intensity in different directions of scattering light inside the biological tissue.     

Origin of diffraction fringes in two-dimensional photoelectron momentum distributions for single ionization of atoms in few-cycle intense laser pulses

We use the strong field approximation with a time window function controlling the release time of electrons to study the intra-cycle and inter-cycle interferences in few-cycle intense laser pulses impinging on He. The diffraction fringes, i.e., the vertical stripe-like structure, observed in the experimental two-dimensional photoelectron momentum distributions of Gopal et al. （2009 Phys. Rev. Lett. 103 053001） have been attributed to the interplay of the intra- and inter-cycle interferences. The pure numerical calculations by solving the time-dependent Schrrdinger equation are also performed and the results are compared with the experimental measurements directly. It has been found that the position of the stripe-like structure can be used to determine the duration of the laser pulses used in experiments.     

Growth and collapse of laser-induced bubbles in glycerol--water mixtures

Comprehensive numerical and experimental analyses of the effect of viscosity on cavitation oscillations are performed. This numerical approach is based on the Rayleigh-Plesset equation. The model predictions are compared with experimental results obtained by using a fibre-optic diagnostic technique based on optical beam deflection （OBD）. The maximum and minimum bubble radii as well as the oscillation times for each oscillation cycle are determined according to the characteristic signals. It is observed that the increasing of viscosity decreases the maximum bubble radii but increases the minimum bubble radii and the oscillation time. These experimental results are consistent with numerical results.     

Motion analysis of light-powered autonomous silver chloride nanomotors

Powered by UV light, nano/micrometer-sized silver chloride particles exhibit autonomous movement and form "schools" in aqueous solution, i.e. regions in which the number density of particles is significantly higher than the global average. In this paper, the silver chloride particles in such a system are classified by their proximity to other AgCl particles -be they isolated, coupled or schooled- and their motion paths are tracked and analyzed. By plotting time-averaged mean squared displacements of each particle over various time intervals from 0.1s to 15.0s, we discover different diffusive behaviors for the three classes of silver chloride particles.     

Charge Densities of Unstable Nuclei with Electron Scattering

Relativistic mean-field theory and phase-shift analysis are combined together to investigate the elastic Coulomb scattering between electrons and unstable nuclei. Electron scattering at several different energies is studied and compared, in order to see the energy dependence of electron-nucleus scattering. It is shown that electron scattering at 200 MeV or 300 MeV can be used to reveal electron-nucleus scattering information around the first diffraction minimum. Shifts in opposite directions are obtained for the first diffraction minima of the electron scattering off the ground and first excited states of ^17F with ^16O as reference, and similar effects are obtained for ^18Ne. Besides, some neutron-rich N = 8 isotones are also studied. Results show that electron scattering will be very useful and important in studying both proton- and neutron-rich nuclei in the future.     

Determination of /Vub/ from measurements of the inclusive charmless semileptonic partial rates of B mesons using full reconstruction tags

We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element /Vub/, based on 253 fb(-1) of data collected by the Belle detector at the KEKB e+ e- asymmetric collider. Events are tagged by fully reconstructing one of the B mesons, produced in pairs from Gamma(4S). The signal for b --> u semileptonic decay is distinguished from the b --> c background using the hadronic mass Mx, the leptonic invariant mass squared q2 and the variable P+ [triple bond] Ex - /px/. The results are obtained for events with p(l)* > or = 1 GeV/c, in three kinematic regions (1) Mx < 1.7 GeV/c2, (2) Mx < 1.7 GeV/c2 combined with q2 > 8 GeV2/c2, and by (3) P+ < 0.66 GeV/c. The matrix element /Vub/ is found to be (4.09 +/- 0.19 +/- 0.20(+0.14) -0.15 +/- 0.18) x 10(-3), where the errors are statistical, systematic including Monte Carlo modeling, theoretical, and from shape function parameter determination, respectively.     

Theoretical Study on N = 126 Shell Evolution

The nuclei around magic number N = 126 are investigated in the deformed relativistic mean field （RMF） model with effective interactions TMA. We focus investigations on the N = 126 isotonic chain. The N = 126 shell evolution is studied by analyzing the variations of two-neutron （proton） separation energies, quadruple deformations, single particle levels etc. The good agreement of two-neutron separation energies between experimental data and calculated values is reached. The RMF theory predicts that the sizes of N = 126 shell become smaller and smaller with the increasing of proton number Z. However, the N = 126 shell exists in our calculated region all along. According to the calculated two-proton separation energies, the RMF theory suggests ^220Pu is a two-proton drip-line nucleus in the N = 126 isotonic chain.     

Gound State Properties of Nuclei in ^295118 α-Decay Chain

The properties of nuclei belonging to the α-decay chain of superheavy element ^295118 have been studied in the framework of axially deformed relativistic mean field （RMF） theory with the parameter set of NL-Z2 in the blocked BCS approximation. Some ground state properties such as binding energies, deformations, and α-decay energies Qα have been obtained and agree well with those from finite-range droplet model （FRDM）. The single-particle spectra of nuclei in ^295118 α-decay chain show that the shell gaps present obviously nucleon number dependence. The root-mean-square （rms） radii of proton, neutron and matter distributions change slowly from ^283112 to ^295118 but dramatically from ^279110 to ^283112, which may be due to the subshell closure at Z = 110 in ^279110. The α-decay half-lives in 295118 decay chain are evaluated by employing the cluster model and the generalized liquid drop model （GLDM）, and the overall agreement is found when they are compared with the known experimental data. The α-decay lifetimes obtained from the cluster model are slightly larger than those of GLDM ones. Finally, we predict the α-decay half-lives of Z=118, 116, 114, 112 isotopes using the cluster model and GLDM, which also indicate these two models can corroborate each other in studies on superheavy nuclei. The results from GLDM are always lower than those obtained from the cluster model.     

Influence of Hyperon-Hyperon Interaction on Properties of Hadronic Star

The influences of hyperon-hyperon interaction on the overall properties of hadronic star are investigated in the framework of relativistic mean field （RMF） theory. For certain hyperon coupling, the weaker hyperon-hyperon interaction can lead to the heavier hadronic star, which accords with the observation of heavy neutron star in X-ray binaries. We find that the threshold densities of the hyperons with larger masses are brought to a lower values with the increase of the hyperon-hyperon interaction. The possibility of the existence of hyperon star is checked with the consideration of hyperon-hyperon interaction.     

Resonant Activation Induced by Four-Value Noise

The phenomenon of the resonant activation （RA） of a particle over a fluctuating potential barrier with a four-value noise is investigated. It is shown that the mean first passage time （MFPT） displays six minima as the function of the transition rates γ1, γ2, γ3, γ4, γ5, and 76 of the four-value noise, respectively. In addition, the effect of other parameters of the system, such as the noise strength D of the additive Gaussian white noise and the parameter value a, b, c, and d of the four-value noise, on the RAs is also investigated.     

Multi-Resonant-Activation for a System Only Driven by Multi-State Noise

We consider the escape of the particles multi-state noise. It is shown that, the noise can make over fluctuating potential barrier for a system only driven by a the particles escape over the fluctuating potential barrier in some circumstances; but in other circumstances, it can not. If the noise can make the particle escape over the fluctuating potential barrier, the mean first passage time （MFPT） can display the phenomenon of multi-resonant-activation. For this phenomenon, there are two kinds of resonant activation to appear. One is resonant activation for the MFPTs as the function of the flipping rates of the fluctuating potential barrier; the other is that for the MFPTs as the functions of the transition rates of the multi-state noise.     

前身中子星转动惯量的研究

The influences of σ^＊ and Ф mesons, temperature and coupling constants of nucleons on the moment of inertia of the proto neutron star （PNS） are examined in the framework of relativistic mean field theory for the baryon octet {n, p, A, ∑^-, ∑^,∑^＋,^-, ^0} system. It is found that, compared with that without considering σ^＊ and Ф mesons, the moment of inertia decreases. It is also found that the higher the temperature, the larger the incompressibility and symmetry energy coefficient, and the larger the moment of inertia of a PNS. The influence of temperature and coupling constants of the nucleons on the moment of inertia of a PNS is larger than that of the σ^＊ and Ф mesons.     

Biased Diffusive Search Triggered by ATP Binding During Kinesin＇s Stepping

In this paper, we present an asymmetry conformational potential with a reflecting boundary and an absorbing boundary, in which the diffusive search of the free head of kinesin motor can be biased toward its forward binding site. Under a wide range of condition, using first-passage time analysis we perform numerical simulation to the Langevin equation, and obtain the dependence of the dwell time for forward steps on the load force. And we calculate the expression for the dwell time by the Laplace transform method. Both numerical and analytical results show that the dwell times exponentially depend on the load force, which provide a simple physical explanation for experimental data. Our results suggest that ATP binding-conformation change in the neck linker plays an important role in unidirectional steps during kinesin＇s mechanochemical cycle.