[en] We study the beam single spin asymmetry in semi-inclusive hadron production in deep inelastic scattering at order 1/Q. There are two competing contributions: the leading order transverse momentum dependent parton distribution h₁^{perpendicular}(x,k_{perpendicular}) convoluted with chiral-odd fragmentation function e-circumflex (z), and the chiral-odd distribution function e(x) convoluted with Collins fragmentation function H₁^{perpendicular}(z,k'_{perpendicular}). We estimate this asymmetry and compare with the experimental measurements from CLAS and HERMES Collaborations

[en] We study the Collins mechanism contribution to the single transverse spin asymmetry in inclusive hadron production in pp scattering p↑p → πX from the leading jet fragmentation. The azimuthal asymmetric distribution of hadron in the jet leads to a single spin asymmetry for the produced hadron in the Lab frame. The effect is evaluated in a transverse momentum dependent model that takes into account the transverse momentum dependence in the fragmentation process. We find the asymmetry is comparable in size to the experimental observation at RHIC at √s = 200GeV

[en] The azimuthal asymmetry of J/ψ suppression in non-central heavy-ion collisions is studied within a dynamic model of J/ψ suppression in a deconfined partonic medium. Within this model, J/ψ suppression in heavy-ion collisions is caused mainly by the initial state nuclear absorption and dissociation via gluon-J/ψ scattering in deconfined partonic medium. Only the second mechanism gives arise to azimuthal asymmetry of the final J/ψ production. We demonstrate that if there is an onset of suppression by quark-gluon plasma (QGP) in the NA50 data, it must be accompanied by the non-vanishing azimuthal asymmetry. Using the same critical density above which the QGP effect enters, we predict the azimuthal asymmetric coefficient ν₂ as well as the survival probability for J/ψ at the RHIC energy

[en] We analyze a class of quantum operations based on a geometrical representation of d-level quantum system (or qudit for short). A sufficient and necessary condition of complete positivity, expressed in terms of the quantum Fourier transform, is found for this class of operations. A more general class of operations on qudits is also considered and its completely positive condition is reduced to the well-known semi-definite programming problem

[en] We study the quark helicity distributions at large x in perturbative QCD, taking into account contributions from the valence Fock states of the nucleon which have nonzero orbital angular momentum. These states are necessary to have a nonzero anomalous magnetic moment. We find that the quark orbital angular momentum contributes a large logarithm to the negative helicity quark distribution in addition to its power behavior, scaling as (1-x)⁵ log²(1-x) in the limit of x → 1. Our analysis show that the ratio of the polarized over unpolarized down quark distributions, Δd/d, will still approach 1 in this limit. By comparing with the current experimental data, we find that this ratio will cross zero at x∼ 0.75

[en] We study the quark helicity distributions at large x in perturbative QCD, taking into account contributions from the valence Fock states of the nucleon which have nonzero orbital angular momentum. These states are necessary to have a nonzero anomalous magnetic moment. We find that the quark orbital angular momentum contributes a large logarithm to the negative helicity quark distributions in addition to its power behavior, scaling as (1-x)⁵ log²(1-x) in the limit of x → 1. Our analysis shows that the ratio of the polarized over unpolarized down quark distributions, Δd/d, will still approach 1 in this limit. By comparing with the experimental data, we find that this ratio should cross zero at x ∼ 0.75

[en] The structural and morphological evolution of magnesium tin composite oxides (MgSnO₃) synthesized by the decomposition of MgSn(OH)₆ at different temperatures was investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The precursor was also studied by thermogravimetric and differential thermal analyses (TG/DTA). The electrochemical performance of MgSnO₃ as anode materials for Li-ion batteries was investigated in the form of Li/MgSnO₃ cells. The results revealed that the samples were microporous materials and the charge capacity and cyclability were sensitive to the structure and morphology of the electrode active materials. The sample heat-treated at 850 deg. C exhibited relatively better electrochemical properties

[en] A series of calculation methods were established in order to calculate the nuclear heating and gain factor accurately, which are two important parameters of hydrogen circulation for the cold neutron source (CNS) in China Advanced Research Reactor (CARR). The verification with reference reactor demonstrates that these methods are correct and effective. Many factors, such as moderator, material of moderator cell, the shape of cell and so on, which would affect the nuclear heating and gain factor, were calculated and optimized for the CNS in CARR. The results show that better gain factor can be gotten with relatively low nuclear heating. (authors)

[en] A self-regulation model and its characteristics of closed two-phase thermosiphon loop, which including buffer tank, were proposed, under the conditions of adiabatic and transient temperature balance for connect tube between buffer tank and condenser. The comparison between these models and the model from Kyoto University is conducted. Measures to improve the self-regulation are proposed. (authors)

[en] The feasibility of the new cooling method in the world, two-phase thermo-siphon with auxiliary cooling, was studied in order to resolving the difficulties in the design of China Advanced Research Reactor (CARR) cold neutron source (CNS). On the basis of feasibility of the new cooling method, the shape of liquid hydrogen in moderator cell was optimized and the better configuration of moderator cell was found by lots of neutronics analyses. additionally, the self-regulation characteristics, which are most important to the stable operation, were researched and the equation of one-order inertial self-regulation was derived by the study of non-balanced thermodynamics analysis. Analysis to the equation results shows that good self-regulation characteristics could be possessed by and optimized. (authors)