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In this work, we investigate the quasi-two-body decays $B_c\to D^*h\to Dπh$ with $h = (K^0,π^0,η,η^{\prime})$ using the perturbative QCD(PQCD) approach. The description of final state interactions between the $Dπ$ pair is achieved through the two-meson distribution amplitudes(DAs), which are normalized to the time-like form factor. The PQCD predictions on the branching ratios of the quasi-two-body decays $B_c\to D^*h\to Dπh$ show an obvious hierarchy: $Br(B_{c}^+ \to D^{*+} K^{0}\to D^0π^+K^{0})=({5.22}_{-0.74}^{+0.86})\times{10}^{-6}, Br(B_{c}^+ \to D^{*+} π^{0}\to D^0π^+π^{0})=(0.93\pm0.26)\times{10}^{-7}, Br(B_{c}^+ \to D^{*+} η\to D^0π^+η) =({2.83}_{-0.52}^{+0.59})\times{10}^{-8}$ and $Br(B_{c}^+ \to D^{*+} η^\prime\to D^0π^+η^\prime)=({1.89}_{-0.36}^{+0.40})\times{10}^{-8}$. From the invariant mass $m_{Dπ}$-dependence of the decay spectrum for each channel, one can find that the branching fraction is concentrated in a narrow region around the $D^{*}$ pole mass. So one can obtain the branching ratios for the corresponding two-body decays $B_c\to D^{*+}h$ under the narrow width approximation. We find that the branching ratios of the decays $B_c\to D^{*+}h$ are consistent well with the previous PQCD calculations within errors. These predictions will be tested by the future experiments., 12 pages, 3 figures, accepted for publication in Chin. Phys. C

In this work we study the quasi-two-body decays $B\to K^*γ\to Kπγ$ in the perturbative QCD (PQCD) approach. The two-meson distribution amplitudes (DAs) are introduced to describe the final state interactions of the $Kπ$ pair, which involve the time-like form factors and the Gegenbauer polynomials. We calculate the CP averaged branching ratios for the decays $B_{(s)}\to K^*γ\to Kπγ$. Our results are in agreement with the new update data measured by Belle II, which suggests these quasi-two-body decays are more appropriate to be analyzed in three-body framework than in the two-body one. We also predict the direct CP-violation asymmetries for the considered decay modes and find that $A_{CP}(B_{u,d}\to K^*γ\to Kπγ)$ is small and less than $1\%$ in magnitude, while $A_{CP}(B_{s}\to K^*γ\to Kπγ)$ is larger and can arrive at a few percent. Our predictions can be tested by the future B meson experiments., 10 pages, 6 figures

In this study, we investigate quasi-two-body decays in the perturbative QCD approach. Two-meson distribution amplitudes are introduced to describe the final state interactions of the pair, which involve time-like form factors and Gegenbauer polynomials. We calculate the CP averaged branching ratios of the decays. Our results are in agreement with newly updated data measured by Belle II. This suggests that it is more appropriate to analyze these quasi-two-body B decays in the three-body framework than the two-body framework. We also predict direct CP asymmetries for the considered decay modes and find that is small and less than % in magnitude, whereas is larger and can reach a few percent. Our predictions can be tested in future B meson experiments.

Mn3O4 and Ce doped Mn3O4 were synthesized via a sol-gel route using metal nitrates as raw materials and citric acid as the chelating agent. The gel precursors were calcined at 300 °C for 12 h in a muffle furnace. Their morphology and structure were characterized using powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Their electrochemical performance as a supercapacitor electrode material was investigated comparatively by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge. The experimental results indicated that Ce- doping did not change the structure of Mn3O4 but greatly affected the morphology and considerably enhanced the electrochemical performance of Mn3O4. A specific capacitance of 477 F·g - 1 was obtained when the mole ratio of Ce ion to total metal ions was 3% , which was 43.7% higher than that of the undoped material. Moreover, Ce-doping significantly improved the capacitance retention ability.

Two new 28-nor-oleanane-type triterpene saponins, oleiferoside U (1), and oleiferoside V (2) were isolated from the 50% EtOH extract of the roots of Camellia oleifera C. Abel. Their structures were elucidated as camellenodiol 3β-O-β-d-galactopyranosyl-(1→2)-β-d-xylopyranosyl-(1→2)-[β-d-galactopyranosyl-(1→3)]-β-d-glucuronopyranoside and camellenodiol 3β-O-β-d-galactopyranosyl-(1→3)-β-d-xylopyranosyl-(1→2)-[β-d-galactopyranosyl-(1→3)]-β-d-glucuronopyranoside. Their chemical structures were established mainly on the basis of integrated spectroscopic techniques. In vitro, cytotoxic activities of the two new triterpene saponins were evaluated against three human tumor cell lines (A549, SMMC-7721, and MCF-7) using the MTT assay. Both of them showed a certain cytotoxic activities toward the tested cell lines and gave IC50 values in the range of 45.04–63.22 μM.

ZnO thin films were prepared on p-type Si (100) substrates by the sol-gel process. The influence of Ag doping at a content of 0.002 % on the photoluminescence and current-voltage (I−V) characteristics of ZnO thin films has been investigated. It is found that Ag doping leads to a pronounced increase in the intensity of near band edge emission at 3.23 eV and a remarkable red shift of the visible broadband at room temperature. The I−V characteristics of ZnO/p-Si heterojunctions are also changed. These results could be explained by Ag substituting for Zn in Ag doped ZnO thin films.

Polypyrrole/graphite oxide composites(PPy/GO) with different mass ratios were first prepared by in situ polymerization and then reduced by NaBH4 to form polypyrrole/reduced graphene oxide(PPy/RGO).The morphology and structure of the composites were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR) and field emission scanning electron microscopy(FESEM).The electrochemical performances of the composites were investigated by cyclic voltammetry,galvanostatic charge discharge and electrochemical impedance techniques.The experimental results showed that the composites with the mass ratio of Py to GO up to 95∶ 5 reached the specific capacitances of 401.5 and 314.5 F/g before and after reduction at the current density of 0.5 A/g,respectively,which were much higher in comparison with pristine GO(34.8 F/g) and PPy(267.5 F/g).The capacitance retention is about 62.5% for PPy/RGO after 1200 cycles,which is much better than those of 16.8% for PPy and 46.4% for PPy/GO,indicating that the PPy/RGO has a high cycle stability and potential as electrode material for supercapacitors.