Flow Investigation on the Directional Instability of Aircraft with the Single Vertical Tail

AbstractAgeneric aircraft with the single vertical tail usually lose its directional stability at medium angle of attack (typically 20° to 30°). A model with moderate sweptwing of 47.5° and a conventional vertical tail is investigated in order to identify physical mechanisms responsible for directional stability. The results show that vertical tail and fuselage are the main components of the aircraft that generate yawing momentby the tests of model parts mounted and dismounted. The broken down vortex at windward side of vertical tail is the main reason for reducingstable yawing moment of vertical tail. Moreover, the middle part of the fuselage including air inlet and forepart of the wing is the main region of the fuselageenhancing unstable yawing moment

Green’s function method to the ground state properties of a two-component Bose–Einstein condensate

The elementary excitation spectrum of a two-component Bose–Einstein condensate is obtained by Green’s function method. It is found to have two branches. In the long-wave limit, the two branches of the excitation spectrum are reduced to one phonon excitation and one single-particle excitation. With the obtained excitation spectrum and the Green’s functions, the depletion of the condensate and the ground state energy have also been calculated in this paper

Revisiting the Bs(∗)B^{(*)}_s-Meson Production at the Hadronic Colliders

The production of heavy-flavored hadron at the hadronic colliders provides a challenging opportunity to test the validity of pQCD predictions. There are two mechanisms for the $B^{(*)}_s$ hadroproduction, i.e. the gluon-gluon fusion mechanism via the subprocess $g+g\rightarrow B^{(*)}_s+b+\bar{s}$ and the extrinsic heavy quark mechanism via the subprocesses $g+\bar{b}\to B^{(*)}_s +\bar{s}$ and $g+s\to B^{(*)}_s +b$, both of which shall have sizable contributions in proper kinematic region. Different from the fixed-flavor-number scheme (FFNS) previously adopted in the literature, we study the $B^{(*)}_s$ hadroproduction under the general-mass variable-flavor-number scheme (GM-VFNS), in which we can consistently deal with the double counting problem from the above two mechanisms. Properties for the $B^{(*)}_s$ hadroproduction are discussed. To be useful reference, a comparative study of FFNS and GM-VFNS is presented. Both of which can provide reasonable estimations for the $B^{(*)}_s$ hadroproduction. At the Tevatron, the difference between these two schemes is small, however such difference is obvious at the LHC. The forthcoming more precise data on LHC shall provide a good chance to check which scheme is more appropriate to deal with the $B^{(*)}_s$-meson production and to further study the heavy quark components in hadrons.Comment: 18 pages, 8 figures, 4 tables. To match the published version. To be published in Eur.Phys.J.

Geometric phase in the Kitaev honeycomb model and scaling behavior at critical points

In this paper a geometric phase of the Kitaev honeycomb model is derived and proposed to characterize the topological quantum phase transition. The simultaneous rotation of two spins is crucial to generate the geometric phase for the multi-spin in a unit-cell unlike the one-spin case. It is found that the ground-state geometric phase, which is non-analytic at the critical points, possesses zigzagging behavior in the gapless $B$ phase of non-Abelian anyon excitations, but is a smooth function in the gapped $A$ phase. Furthermore, the finite-size scaling behavior of the non-analytic geometric phase along with its first- and second-order partial derivatives in the vicinity of critical points is shown to exhibit the universality. The divergent second-order derivative of geometric phase in the thermodynamic limit indicates the typical second-order phase transition and thus the topological quantum phase transition can be well described in terms of the geometric-phase.Comment: 7 pages, 8 figure

A Flexion Mode Piezoelectric Micro-Transformer Processed by Aerosol Deposition Method

International audienc

Proton–neutron asymmetry independence of reduced single-particle strengths derived from (p,d) reactions

An overall reduction factor (ORF) is introduced for studying the quenching of single-particle strengths through nucleon transfer reactions. The ORF includes contributions of all the probed bound states of the residual nucleus in a transfer reaction and permits a proper comparison with results of inclusive knockout reactions. A systematic analysis is made with 103 sets of angular distribution data of (p,d) reactions on 21 even–even targets with atomic mass numbers from 8 to 56 using the consistent three-body model reaction methodology proposed in Lee et al. (2006) [25]. The extracted ORFs are found to be nearly independent on the proton–neutron asymmetry, which is different from the systematics of inclusive knockout reactions but is consistent with the recent measurement of (d,t), (d,He3), (p,2p), and (p,pn) reactions on nitrogen and oxygen isotopes and ab initio calculations. Keywords: (p,d) reactions, Spectroscopic factors, Quenching factors, Reduced single-particle strengt