Some Remarks on the Final State Interactions in B→πKB\to \pi K Decays

Careful discussions are made on some points which are met in studying B decay final state interactions, taking the $B^0\to \pi^+ K^-$ process as an example. We point out that $\pi$--exchange rescatterings are not important, whereas for $D^*$ and $D^{**}$ exchanges, since the $B^0\to D^+D_s^-$ decay has a large branching ratio their contributions may be large enough to enhance the $B\to \pi K$ branching ratio significantly. However our estimates fail to predict a large enhancement.Comment: 5 pages, use elsart.sty; The previous version is erroneous in explaining the "charm peguin" effects. No large enhancement to $B\to \pi K$ is found through $D^+D_s^-$ intermediate stat

B(s)→SB_{(s)}\to S transitions in the light cone sum rules with the chiral current

$B_{(s)}$ semi-leptonic decays to the light scalar meson, $B_{(s)}\to S l\bar{\nu}_l, S l \bar{l}\,\,(l=e,\mu,\tau)$, are investigated in the QCD light-cone sum rules (LCSR) with chiral current correlator. Having little knowledge of ingredients of the scalar mesons, we confine ourself to the two quark picture for them and work with the two possible Scenarios. The resulting sum rules for the form factors receive no contributions from the twist-3 distribution amplitudes (DA's), in comparison with the calculation of the conventional LCSR approach where the twist-3 parts play usually an important role. We specify the range of the squared momentum transfer $q^2$, in which the operator product expansion (OPE) for the correlators remains valid approximately. It is found that the form factors satisfy a relation consistent with the prediction of soft collinear effective theory (SCET). In the effective range we investigate behaviors of the form factors and differential decay widthes and compare our calculations with the observations from other approaches. The present findings can be beneficial to experimentally identify physical properties of the scalar mesons.Comment: 22 pages,16 figure

Electrochemical Behavior and Electrochemical Determination of Tiamulin Fumarate at an Ionic Liquid Modified Carbon Paste Electrode

The electrochemical behavior of tiamulin fumarate (TF) at ionic liquid N-Butylpyridinium hexafluorophosphate (BPPF6) modified carbon paste electrode (BPPF6/CPE) was investigated and further used for tiamulin fumarate sample determination. BPPF6/CPE showed an enhanced electrochemical response towards the electrochemical oxidation of TF. A well-defined and sensitive oxidation peak was observed at BPPF6/CPE in 0.10 M phosphate buffer solution (PBS, pH = 6.80). The oxidation peak current of TF increased significantly at BPPF6/CPE compared with that at carbon paste electrode and the BPPF6/CPE was characterized by the electrochemical impedance spectroscopy (EIS). At the same time, the electrochemical kinetics parameters of TF on the BPPF6/CPE were evaluated. Under the optimized conditions, the oxidation peak currents were linearly dependent on the concentration of TF in the range of 0.3–9.0 μM and 9.0–0.3 mM, with a detection limit of 0.16 μM (S/N = 3). The proposed method has been successfully applied in the electrochemical quantitative determination of TF content in commercial injection samples

Monitoring and analysis of blasting vibration in tunnel excavation of nuclear power plant

Vibration monitoring of blasting excavation of drainage tunnel in Lufeng Nuclear Power Plant is carried out and the data of blasting vibration is analyzed in this paper. The results show that: (1) The vertical vibration velocity of the rock mass is greater than the horizontal radial and horizontal tangential vibration velocity (2) The blasting vibration velocity of rock mass decreases with distance, which is affected by rock structure and explosive quantity. The monitoring research in this paper has guiding significance for vibration prediction and control in tunnel blasting excavation

Isospin dependence of nucleon effective mass in Dirac Brueckner-Hartree-Fock approach

The isospin dependence of the nucleon effective mass is investigated in the framework of the Dirac Brueckner-Hartree-Fock (DBHF) approach. The definition of nucleon scalar and vector effective masses in the relativistic approach is clarified. Only the vector effective mass is the quantity related to the empirical value extracted from the analysis in the nonrelatiistic shell and optical potentials. In the relativistic mean field theory, where the nucleon scalar and vector potentials are both energy independent, the neutron vector potential is stronger than that of proton in the neutron rich nuclear matter, which produces a smaller neutron vector effective mass than that of proton. It is pointed out that the energy dependence of nucleon potentials has to be considered in the analysis of the isospin dependence of the nucleon effective mass. In the DBHF the neutron vector effective mass is larger than that of proton once the energy dependence of nucleon potentials is considered. The results are consistent with the analysis of phenomenological isospin dependent optical potentials.Comment: 4 pages, 3 Postscript figure

Electrochemical behavior of lansoprazole at a multiwalled carbon nanotubes-ionic liquid modified glassy carbon electrode and its electrochemical determination

The electrochemical behavior of lansoprazole (LNS) has been investigated at a glassy carbon electrode (GCE) and the electrode modified by a gel containing multiwalled carbon nanotubes (MWCNTs) and an room-temperature ionic liquid (RTIL) of 1-Butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) in 0.10 M phosphate buffer solution of pH 6.8. It was found that an irreversible anodic oxidation peak with Epa as 1.060 V appeared at MWCNTs-RTIL/GCE. Under the optimized experimental conditions a linear calibration curve were obtained over the concentration range from 5.0 μM to 0.20 mM by differential pulse voltammetry with the limit of detection (LOD, S/N = 3) as 0.28 μM. In addition, the novel MWCNTs-RTIL/GCE was also characterized by the electrochemical impedance spectroscopy and the proposed method has been successfully applied in the electrochemical quantitative determination of LNS content in commercial tablet samples and the determination results could meet the determination requirement