[en] In this work we investigate the weak Λ_b→Λ_c semileptonic and nonleptonic decays. The light-front quark model and diquark picture for heavy baryons are adopted to evaluate the Λ_b→Λ_c transition form factors. In the heavy quark limit we study the Isgur-Wise function. The transition form factors are obtained in the whole physical momentum regions. The numerical predictions on the branching ratios of nonleptonic decay modes Λ_b→Λ_cM and various polarization asymmetries are made. A comparison with other approaches is discussed

[en] Based on the assumption that D_sJ^*(2317) and D_sJ(2460) are the (0⁺,1⁺) chiral partners of D_s and D^*_s, we evaluate the strong pionic and radiative decays of D_sJ^*(2317) and D_sJ(2460) in the constituent quark meson (CQM) model. Our numerical results of the relative ratios of the decay widths are reasonably consistent with the data. (orig.)

[en] Based on the set of nonlinear coupling equations, which has considered the relativistic effects of electrons, modulational instability by strong Langmuir waves has been investigated in this paper. Both the characteristic scale and maximum growth rate of the Langmuir field will enhance with the increase in the electron relativistic effect. The numerical results indicate that longitudinal perturbations induce greater instability than transverse perturbations do, which will lead to collapse and formation of the pancake-like structure.

[en] Using a kinetic description, the relativistically strong Langmuir turbulence is investigated, which has considered the nonlinear wave-wave, wave-particle interactions and the relativistic effects of electrons. The relativistic Zakharov equations have been obtained. On the basis of these equations, dynamics of collapse has been studied. It is shown that the field strength of relativistic Langmuir plasmons will increase and the ponderomotive expulsion of particles gives rise to the formation of density caviton during the collapsing, which is useful for understanding the natural structural element of relativistically strong Langmuir turbulence.

[en] Shape evolutions in the neutron-rich Ru isotopes were investigated using the cranked shell model and an excellent agreement was obtained in comparison with the experimental data. These results show that the cranked shell model with nonaxial deformed Woods-Saxon potential can provide a good description of the shape evolution in the neutron-rich Ru isotopes in terms of not only neutron number but also angular momentum.

[en] Single curvature parts such as aircraft fuselage skin panels are usually manufactured by rolling-chemical milling process, which is usually faced with the problem of geometric accuracy caused by springback. In most cases, the methods of manual adjustment and multiple roll bending are used to control or eliminate the springback. However, these methods can cause the increase of product cost and cycle, and lead to material performance degradation. Therefore, it is of significance to precisely control the springback of rolling-chemical milling process. In this paper, using the method of experiment and numerical simulation on rolling-chemical milling process, the simulation model for rolling-chemical milling process of 2060-T8 aluminum-lithium alloy skin was established and testified by the comparison between numerical simulation and experiment results for the validity. Then, based on the numerical simulation model, the relative technological parameters which influence on the curvature of the skin panel were analyzed. Finally, the prediction of springback and the compensation can be realized by controlling the process parameters. (paper)

[en] In this paper we report a fiber-type widely tunable CW mid-IR DFG/QPM laser source based on periodically poled MgO-doped LiNbO₃ (PPMgLN), which uses a ytterbium-dope fiber laser (YDFL) as the pump source and a tunable erbium-dope fiber laser (EDFL) cascaded with an erbium-doped fiber amplifier (EDFA) as the signal source. Our experimental results show that, with the PCs to adjust the pump and signal polarization orientations being parallel to the crystal principle optical axis the conversion efficiency may be optimized. The pump and signal beam spots and their longitudinal evolution behaviors determine the RCE and the crystal longitudinal position tolerance, which are measured to be 0.717 (mW)^-2 and 44 mm for the mid-IR laser source, respectively. The idler output of the mid-IR DFG/QPM laser source may be continuously tuned from 3.1 to 3.6 μm with almost the same RCE

[en] The dynamic simulation of casting ultrasonic vibration system were studied based on dynamic characteristics of the system and numerical simulation of ultrasonic sound pressure field under different vibration depths in water was performed. According to the simulation results, the cavitation region was estimated, and the experiment of cavitation erosion of aluminum foil in water and amplitude test were done to verify simulation results. The results showed that the longitudinal vibration at the end of face was the major vibration of ultrasonic radiation, while there was a strong vibration on cylindrical surface. Results of amplitude test are consistent with simulation results. Cavitation region caused by ultrasonic vibration mainly below the end face of radiation. The scope and intensity of cavitation were inversely related to the distance from the end face of radiation. With the vibrating depth increased, some small cavitation regions were found at the side of radiation, cavitation region distributed uncontinuously below radiation. Cavitation field measurement and simulation results were basically consistent

[en] In this paper, nickel oxides (NiO) and iron (Fe)-doped NiO nanowires (NWs) with the various doping content (from 1 to 9 at%) were synthesized by using SBA-15 templates with the nanocasting method. All samples were synthesized in the same conditions and exhibited the same mesoporous-structures, uniform diameter, and defects. Mesoporous-structures with high surface area created more active sites for the adsorption of oxygen on the surface of all samples, resulting in the smaller surface resistance in air. The impurity energy levels from the donor Fe-doping provided electrons to neutralize the holes of p-type Fe-doped NiO NWs, which greatly enhanced the total resistance. The comparative gas-sensing study between NiO NWs and Fe-doped NiO NWs indicated that the high-valence donor Fe-doping obviously improved the ethanol sensitivity and selectivity for Fe-doped NiO NWs. And Ni_0.94Fe_0.06O_1.03 NWs sensor presented the highest sensitivity of 14.30 toward ethanol gas at 320 °C for the high-valence metal-doping.

[en] We have fabricated Co₂FeAl (CFA) films with perpendicular magnetic anisotropy (PMA) in a (Co₂FeAl/Ni)₆ multilayer structure. The effects of underlayer Cu thickness (t_Cu), Co₂FeAl thickness (t_CFA) and Ni thickness (t_Ni) on the magnetic properties have been studied. The PMA is realized with a large anisotropy energy density K = 3.7x10⁶ ergs/cm³, a high squareness M_r/M_s = 1 and a small perpendicular coercivity H_c = 60 Oe, while t_Cu, t_CFA and t_Ni are 9 nm, 0.2 nm and 0.6 nm respectively. The PMA remains after 300 ⁰C annealing, which demonstrates better thermal stability of the (Co₂FeAl/Ni)₆ multilayer than that of (Co/Ni)_n.