[en] High quality single domain YBCO bulk superconductors, 20 mm in diameter, have been fabricated using a new top seeded infiltration and growth method (called the RE + 011 TSIG method), with a new solid phase (Y_2O_3 + xBaCuO_2) instead of the conventional Y_2BaCuO_5 solid phase, x = 0, 0.5, 1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 3.0. The effects of different BaCuO_2 contents x on the growth morphology, microstructure, and levitation force have been investigated. The results show that the levitation force of the YBCO bulks first increases and then decreases with increasing x, and reaches maximum levitation forces of about 49.2 N (77 K, 0.5 T, with the traditional liquid phase of YBa_2Cu_3O_y + 3 BaCuO_2 + 2 CuO) and 47 N (77.3 K, 0.5 T, with the new liquid phase of Y_2O_3 + 10 BaCuO_2 + 6 CuO) when x = 1.2, which is much higher than that of the samples fabricated with the conventional solid phases (23 N). The average Y_2BaCuO_5 particle size is about 1 μm, which is much smaller than the 3.4 μm in the samples prepared with the conventional Y_2BaCuO_5 solid phase; this means that the flux pinning force of the sample can be improved by using the new solid phase. Based on this method, single domain YBCO bulks 40 mm, 59 mm, and 93 mm in diameter have also been fabricated using the TSIG process with the new solid phases (Y_2O_3 + 1.2BaCuO_2). These results indicate that the new TSIG process developed by our lab is a very important and practical method for the fabrication of low cost, large size, and high quality single domain REBCO bulk superconductors. (paper)

[en] The control of attitude of a satellite is difficult to verify since several subsystems of different disciplines, e.g., flexible multibody dynamics, machines, electronics and control, are involved and strongly coupled. A traditional method is to model each single discipline subsystem with a domain specific software, and combine them through interfaces. However, the problems are that lots of interfaces between software have to be developed, and manual decoupling of systems should be considered during modelling process. In this Paper, models of the dynamics and the control system are established in a unified modelling software, MWorks, which is an Integrated Development Environment of Modelica. The model can be used to verify the satellite control strategy, and also provide an effective means for satellite attitude control system design. Moreover, on this basis, the whole satellite was modelled to access state parameters changes under the coupling of the dynamic subsystem, the attitude control subsystem, the power supply subsystem, the propulsion subsystem and the integrated electronic subsystem can be synthetically considered. (paper)

[en] In this paper we report a new sol-gel method for the fabrication of MgB₂ films. Polycrystalline MgB₂ films were prepared by spin-coating a precursor solution of Mg(BH₄)₂ diethyl ether on (001)Al₂O₃ substrates followed with annealing in Mg vapor. In comparison with the MgB₂ films grown by other techniques, our films show medium qualities including a superconducting transition temperature of T_C ∼ 37 K, a critical current density of J_C(5 K, 0 T) ∼ 5 x 10⁶ A cm^-2, and a critical field of H_C2(0) ∼ 19 T. Such a sol-gel technique shows potential in the commercial fabrication of practically used MgB₂ films as well as MgB₂ wires and tapes.

[en] We present measurements of the charmonium state h_c(¹P₁) made with 106x10⁶ ψ^' events collected by BESIII at BEPCII. Clear signals are observed for ψ^'→π⁰h_c with and without the subsequent radiative decay h_c→γη_c. First measurements of the absolute branching ratios B(ψ^'→π⁰h_c)=(8.4±1.3±1.0)x10^-4 and B(h_c→γη_c)=(54.3±6.7±5.2)% are presented. A statistics-limited determination of the previously unmeasured h_c width leads to an upper limit Γ(h_c)<1.44 MeV (90% confidence). Measurements of M(h_c)=3525.40±0.13±0.18 MeV/c² and B(ψ^'→π⁰h_c)xB(h_c→γη_c)=(4.58±0.40±0.50)x10^-4 are consistent with previous results.

[en] Using a sample of 1.06x10⁸ ψ^' decays collected by the BESIII detector, χ_c0 and χ_c2 decays into π⁰π⁰ and ηη are studied. The branching fraction results are Br(χ_c0→π⁰π⁰)=(3.23±0.03±0.23±0.14)x10^-3, Br(χ_c2→π⁰π⁰)=(8.8±0.2±0.6±0.4)x10^-4, Br(χ_c0→ηη)=(3.44±0.10±0.24±0.2)x10^-3, and Br(χ_c2→ηη)=(6.5±0.4±0.5±0.3)x10^-4, where the uncertainties are statistical, systematic due to this measurement, and systematic due to the branching fractions of ψ^'→γχ_cJ. The results provide information on the decay mechanism of χ_c states into pseudoscalars.

[en] The DOe detector is used to study pp-bar collisions at the 1800 and 630 GeV center-of-mass energies available at the Fermilab Tevatron. To measure jets, the detector uses a sampling calorimeter composed of uranium and liquid argon as the passive and active media, respectively. Understanding the jet energy calibration is not only crucial for precision tests of QCD, but also for the measurement of particle masses and the determination of physics backgrounds associated with new phenomena. This paper describes the energy calibration of jets observed with the DOe detector at the two pp-bar center-of-mass energies in the transverse energy and pseudorapidity range E_T>8 GeV and vertical bar η vertical bar <3