Unified description of angular distributions of target particles in light and heavy ion induced interactions in nuclear emulsions at high energies

Some investigations show that in light ion （LI） induced reactions, such as He, O, Ne, and Ar in nuclear emulsions （Em） at high energies, the angular distributions of the target particles show a wide structure around the polar angle V ≈ 60°. With heavy ions （HI） such as Kr and Au such a wide structure has not been observed. The experimental results on Mg-Em and Si-Em interactions also do not show such a wide structure in the angular distribution of the target particles. Using a multisource ideal gas model we uniformly describe the angular distributions of the target particles produced in LI-Em and HI-Em interactions. The result is not only in agreement with the mean trend, but also with the fluctuations of the experimental data. We conclude that the wide structure observed in LI-Em interactions may be the result of statistical fluctuations.     

The low-lying rotational bands of the neutron-rich nucleus <Superscript>172</Superscript>Tm

The microscopic mechanism of four experimentally observed bands in 172Tm is investigated using the particle-number conserving method of the cranked shell model with monopole and quadrupole paring interactions.The experimental results,including the moments of inertia and angular momentum alignments of four bands in 172Tm are reproduced well by the particle-number conserving calculations.The ω variation of the occupation probability of each cranked orbital and the contribution to moment of inertia from each c...     

Waveguide modulated non-local optical interaction of semiconductor microdisks

The non-local optical interaction of two semiconductor microdisks with a waveguide bridged at radial direction is proposed and studied by three dimensional finite-difference time-domain （FDTD） electromagnetic simulations. The strong and weak optical interactions between two microdisks are observed and ascribed to the internal coupled modes with different coupling ratios. The vertical radiation losses and the related mode quality factors are modulated by waveguide length and present oscillation characteristics for the resonant modes. In addition, the optical leakage of coupling system is affected by the etching depth of disks due to tile emission of minor components of electric field.     

Ground-state vortex structures of a rotating binary dipolar Bose–Einstein condensate confined in harmonic plus quartic potential

We consider a binary dipolar Bose–Einstein condensate confined in a rotating harmonic plus quartic potential trap.The ground-state vortex structures are numerically obtained as a function of the contact interactions and the dipole–dipole interaction in both slow and rapid rotation cases. The results show that the vortex configurations depend strongly on the strength of the contact interactions, the relative strength between dipolar and contact interactions, as well as on the orientation of the dipoles. A variety of exotic ground-state vortex structures, such as pentagonal and hexagon vortex lattice,square vortex lattice with a central vortex, annular vortex lines, and straight vortex lines, are observed by turning such controllable parameters. Our results deepen the understanding of effects of dipole–dipole interaction on the topological defects.     

Exploratory study of possible resonances in heavy meson-heavy baryon coupled-channel interactions

We use a unitary coupled-channel model to study the DA_c-D∑_c interactions. In our calculation, SU(3)flavor symmetry is applied to determine the coupling constants. Several resonant and bound states with different spin and parity are dynamically generated in the mass range of the recently observed pentaquarks. The approach is also extended to the hidden beauty sector to study the BΛ_b-B∑_b interactions. As the b-quark mass is heavier than the c-quark mass, there are more resonances observed for the BΛ_b-B∑_b interactions and they are more tightly bound.     

The coupled motions of bubbles in ultrasonic fiel

The dynamic responses of bubbles in ultrasonic field include the radial vibration, translation,and their interactions.Based on the radial vibration modal where the secondary radiation of neighboring bubbles was considered,and interaction forces of bubbles,the coupled motions of two bubbles with different size in a plane ultrasonic field was simulated numerically. The results show that the radial vibration of a big bubble has natural properties and its translation velocity is rapid relatively.The behavior and distribution of bubbles was observed experimentally by using high speed photography.It is shown that the big bubbles translate rapidly in bubble clouds and vibrate radially with small-amplitude.On the other hand,the phenomena of attraction and coalescence among bubbles is observed,which may attribute to the effects of secondary radiation between neighboring bubbles.     

Computational studies on the interactions of nanomaterials with proteins and their impacts

The intensive concern over the biosafety of nanomaterials demands the systematic study of the mechanisms underlying their biological effects. Many of the effects of nanomaterials can be attributed to their interactions with proteins and their impacts on protein function. On the other hand, nanomaterials show potential for a variety of biomedical applications,many of which also involve direct interactions with proteins. In this paper, we review some recent computational studies on this subject, especially those investigating the interactions of carbon and gold nanomaterials. Beside hydrophobic andπ-stacking interactions, the mode of interaction of carbon nanomaterials can also be regulated by their functional groups.The coatings of gold nanomaterials similarly adjust their mode of interaction, in addition to coordination interactions with the sulfur groups of cysteine residues and the imidazole groups of histidine residues. Nanomaterials can interact with multiple proteins and their impacts on protein activity are attributed to a wide spectrum of mechanisms. These findings on the mechanisms of nanomaterial–protein interactions can further guide the design and development of nanomaterials to realize their application in disease diagnosis and treatment.     

Evidence of intermittent fluctuation of target fragments in ^84Kr-AgBr interactions at 1.7 A GeV

Intermittency and fractal behaviour have been studied of emission spectra of target associated fragments from ^84Kr-AgBr interactions at 1.7 A GeV in emission angle space and azimuthal angle space separately. The intermittent behaviour is observed in the two spaces separately. Prom the intermittency exponent, the anomalous fractal dimension dq is calculated and the variation of dq with the order q is investigated. It is found that the anomalous dimensions are found to increase with the order of moments q, thereby indicating the relation of multifractality to production mechanism of target associated fragments.     

Hadronic Scenarios for Gamma-Ray Emission from Three Supernova Remnants Interacting with Molecular Clouds

GeV γ-rays detected with the large area telescope on board the Fermi Gamma-ray space telescope in the direc- tion of HB21, MSH 17-39 and G337.0-0.1 have been recently reported. The three supernova remnants （SNRs） show interactions with molecular clouds, and they are effective gamma-ray emitters as the relativistic protons accelerated by the SNR shocks inelastically colliding with the dense gas in the clouds. The origin of the observed γ-rays for the three remnants is investigated in the scenario of the diffusive shock acceleration. In the model, a part of the SNR shock transmits into the nearby molecular clouds, and the shock velocity is greatly reduced. As a result, a shock with a relatively low Alfven Mach number is generated, and the spectra of the accelerated protons and thee＇γ-ray photons produced via proton-proton interaction can be obtained. The results show that the observed γ-ray spectra for the three SNRs interacting with the molecular clouds can be reproduced. It can be concluded that the hadronic origin of the γ-rays for the three SNRs is approved, and the ability of SNR shocks to accelerate protons is also supported.     

Proton Orbital [541]1/2 and Backbending in 178W

The microscopic mechanism of nine experimentally observed bands in ^178W is investigated using the particle-number conserving method of the cranked shell model with monopole and quadrupole paring interactions. The experimental results, including the moments of inertia and angular momentum alignments of nine bands in ^178W, are reproduced well by the particle-number conserving calculations, in which no free parameter is involved. Calculations demonstrate that occurrence of sharp backbending comes mainly from the contribution of high-j intruder orbitals vi13/2 or πh11/2 and their interference effect with orbitals near the Fermi surface. Theω variation of the occupation probability of each cranked orbital and the contribution to moment of inertia from each cranked orbital are analyzed.     

On the order-disorder transition of chemisorbed H on Ni (111)

The recently observed order-disorder transition of chemisorbed H on Ni(111) is analyzed in terms of the cluster-variation method including not only H-pair interactions but also interactions between 3 chemisorbed H-atoms. The dependence of the transition temperature, the LEED intensity spots and the H-binding energy on H-coverage has been calculated. It is shown that the observed asymmetric phase-diagram with respect to H-coverage can result from interactions between 3 H-atoms.     

Inelastic interactions of 9.38 GeV/c deuteron in emulsion

Characteristics of the inelastic interactions of 9.38 GeV/c deuterons with nuclear emulsion nuclei have been studied. These have been compared with nucleon-nucleus interactions at a corresponding momentum. The probability of nucleon stripping in deuteron-nucleus interactions has been observed to be 0.5. The charged particle multiplicity in deuteron-nucleus interactions exhibitA-dependence of the typeA ^α with α=0.08. The experimental data disagree with KNO scaling.     

Chemical bond model of lattice distortions in hexagonal layers

The lattice distortions of a hexagonal layer are discussed in terms of a simple model with isotropic interactions. If only nearest-neighbour interactions are considered, the only stable distorted structures are the MnP structure (with zig-zag chains) and the low-temperature NbS structure (with triangles of metal atoms). If also interactions with more distant atoms are considered, more complicated distortions, as observed in crystals with charge density waves, are possible.     

Dual properties of lattice systems with broken symmetry: Ising and potts chains in an external field

Dual transformation that produces a path between inhomogeneous spin chains in a site-dependent potential and inhomogeneous spin chains with nonconstant interactions is established. It implies coupling of equivalent random versions of theoretical models. The duality is observed for a number of spin chains with nearest-neighbour as well as multispin interactions.     

Controlling Soliton Collisions of Condensates by Time-Dependence of Both Interactions and External Potential

Considering time-dependence of both interactions and external potential, we analytically study the collisional behaviors of two bright solitons in Bose-Einstein condensates by using Darboux transformation. It is found that for a closed external potential, the soliton-soliton distance is decreased with nonlinearly increased interactions, while the amplitude of each soliton increases and its width decreases. For linearly increased interactions but nonlinearly decreased external potential, especially, the atom transfer between two solitons is observed, different from previous theory of no atom transfer in solitons collision in a fixed external potential. In addition, it is shown that the collisional type, such as head-on,"chase", or collision period between two solitons, can be controlled by tuning both interactions and external potential. The predicted phenomena can be observed under the condition of the current experiments and open possibilities for future application in atoms transport.     

Pressure-induced intermolecular interactions in crystalline silane-hydrogen

The structure and dynamics of a recently discovered solid silane-hydrogen complex under high pressure are elucidated with first-principles molecular dynamics calculations. A structure with orientationally disordered silane and hydrogen with their centers of mass arranged in a distinctive manner are found. Natural bond orbital analysis reveals that perturbative donor-acceptor interactions between the two molecular species are enhanced by pressure. The experimentally observed anticorrelated pressure-frequency dependency is a consequence of these novel interactions. Moreover, the experimentally observed multiple Raman peaks of H2 can be explained by temporal changes in the environment due to deviations of the lattice parameters from the ideal cubic lattice.     

Unified description of angular distributions of target particles in light and heavy ion induced interactions in nuclear emulsions at high energies

Some investigations show that in light ion (LI) induced reactions, such as He, O, Ne, and Ar in nuclear emulsions (Em) at high energies, the angular distributions of the target particles show a wide structure around the polar angle ν≈ 60°. With heavy ions (HI) such as Kr and Au such a wide structure has not been observed. The experimental results on Mg--Em and Si--Em interactions also do not show such a wide structure in the angular distribution of the target particles. Using a multisource ideal gas model we uniformly describe the angular distributions of the target particles produced in LI--Em and HI--Em interactions. The result is not only in agreement with the mean trend, but also with the fluctuations of the experimental data. We conclude that the wide structure observed in LI--Em interactions may be the result of statistical fluctuations.     

Evidence of interactions in Co-HfO2 granular films

Co-HfO(2) granular films with varying numbers of bilayers were studied by means of transmission electron microscopy (TEM), magnetization loops and zero-field-cooled and field-cooled (ZFC-FC) magnetization. Grain size properties inferred from the measurement techniques were found to be different from those observed from TEM. We show that a modified Langevin function that accounts for dipolar interactions reconciles grain size properties observed by TEM. The mean blocking temperature seen from ZFC-FC analysis was observed to be greater compared to that inferred from TEM data. Moreover, it exhibited a trend with increasing numbers of bilayers. We proposed an explanation for these differences on the basis of the degree of dipolar interactions.     

Tl-related radiation defects in CsI:Tl

Angular dependencies of the EPR spectra detected via the magnetic circular dichroism of the optical absorption (MCDA-EPR) observed in the MCDA bands at 355, 411, 425, 442, 465, 536, and 815 nm of γ- or X-irradiated CsI:Tl crystals have been investigated. The MCDA-EPR spectrum at B || [1 0 0] consists of two quartets of intense lines. The spectrum could be satisfactorily explained taking into account hyperfine (hf) interactions of unpaired electron with with three Tl nuclei I (205Tl, . Therefore we propose as a model a Tl-trimer centre. The hf interactions along a [1 0 0] direction with two equivalent Tl and one single Tl were observed. As a centre model we propose TlCs++–Tli0–TlCs++. The Tl hf interactions observed can be explained qualitatively in a ionic model for this trimer centre.     

Neutrino propagation in a medium with a magnetic field

Data on the mean multiplicity of strange hadrons produced in minimum bias proton-proton and central nucleus-nucleus collisions at momenta between 2.8 and 400 GeV/c per nucleon have been compiled. The multiplicities for nucleon-nucleon interactions were constructed. The ratios of strange particle multiplicity to participant nucleon as well as to pion multiplicity are larger for central nucleus-nucleus collisions than for nucleon-nucleon interactions at all studied energies. The data at AGS energies suggest that the latter ratio saturates with increasing masses of the colliding nuclei. The strangeness to pion multiplicity ratio observed in nucleon-nucleon interactions increases with collision energy in the whole energy range studied. A qualitatively different behaviour is observed for central nucleus-nucleus collisions: the ratio rapidly increases when going from Dubna to AGS energies and changes little between AGS and SPS energies. This change in the behaviour can be related to the increase in the entropy production observed in central nucleus-nucleus collisions at the same energy range. The results are interpreted within a statistical approach. They are consistent with the hypothesis that the Quark Gluon Plasma is created at SPS energies, the critical collision energy being between AGS and SPS energies.