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Temperature dependent Raman spectra and photoluminescence, as well the Raman mapping of different parts in an individual Sn-doped CdS comb-like nanostructure reveal that the stronger electron-phonon coupling exist at the trunk-branch junctions than other parts. The Huang-Rhys factor was calculated and further confirms that the strong electron-phonon correlation at the junction. The localized deformation from the Sn dopant in the lattice leads to strong electron-phonon coupling at the local junction, which is proved by the scanning transmission electron microscope and energy dispersion spectrum. Moreover, the lifetime of near-band-edge emission and deep-level emission drastically increase with decreasing temperature, which both relate to the localized electron-phonon coupling and relaxation process. This work provides a clear description of the localized carrier correlation in the cross junction part of these branched nanostructures, which can be used to modulate the optoelectronic performance of micro nanodevices.

Large-scale synthesis of aligned carbon nanotubes was achieved by using a method based on chemical vapor deposition catalyzed by iron nanoparticles embedded in mesoporous silica. Scanning electron microscope images show that the nanotubes are approximately perpendicular to the surface of the silica and form an aligned array of isolated tubes with spacings between the tubes of about 100 nanometers. The tubes are up to about 50 micrometers long and well graphitized. The growth direction of the nanotubes may be controlled by the pores from which the nanotubes grow.

BackgroundLTCBDE combined with or without modified techniques is safe and efficacious for the management of gallstones and concomitant, even large, common bile duct (CBD) stones.MethodsTo describe the surgical indications and procedure strategies of laparoscopic transcystic common bile duct exploration (LTCBDE), a retrospective analysis of 205 patients with concomitant gallstones and CBD stones treated using LTCBDE between June 2008 and June 2015 was performed. Clinical data on disease characteristics, methods for cystic duct incision and CBD stone extraction (with or without laser lithotripsy), and surgical outcomes were collected and reviewed.ResultsCBD stones were successfully cleared in all patients. No patient was converted to choledochotomy or laparotomy. The cystic duct diameter ranged 3–8 mm, and 85 patients with cystic duct diameter ≥ 5 mm. The mean time for CBD stone extraction was 25.3 min, with the operative time ranged from 63 to 170 min. Lithotripsy was used in 74 (36.1%) patients among which 26 patients with cystic duct diameter ≥ 5 mm. Estimated blood loss during surgery was 10–120 ml per patient, and no intra-operative blood transfusions were needed. The mean postoperative hospital stay was 5.1 (range 3–7) days, and postoperative complications developed in seven patients. No bile duct injury, stricture, remnant, recurrent stones, or other adverse events were observed during the mean follow-up of 8 months.ConclusionsBased on preoperative MRCP and intra-operative IOC findings about cystic duct diameter, the diameter of CBD, CBD stone size, we summarized and proposed the surgical indications and suitable techniques and strategies during LTCBDE.

The electrical resistances of ZnO powder and nanocrystals produced by a microemulsion method were studied under pressure up to 24 GPa in a diamond anvil cell. The experimental data are different from those previously reported using other techniques. The resistance of ZnO powder rises gradually with increasing pressure until 4.8 GPa and then decreases above 4.8 GPa. The transition point pressure (4.8 GPa) is much smaller than that of 9 GPa for the first order structural transition pressure of bulk ZnO. A similar profile of the electrical resistance versus pressure relationship for ZnO nanocrystals (20 nm) occurs at a higher pressure (8.5 GPa) than that determined for ZnO powder. The cause of these phenomena is discussed.

The super τ-charm facility (STCF) is an electron−positron collider proposed by the Chinese particle physics community. It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5 × 10 35 cm −2·s −1 or higher. The STCF will produce a data sample about a factor of 100 larger than that of the present τ-charm factory - the BEPCII, providing a unique platform for exploring the asymmetry of matter-antimatter (charge-parity violation), in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions, as well as searching for exotic hadrons and physics beyond the Standard Model. The STCF project in China is under development with an extensive R&D program. This document presents the physics opportunities at the STCF, describes conceptual designs of the STCF detector system, and discusses future plans for detector R&D and physics case studies.

The decay D→K-π+ is studied in a sample of quantum-correlated DD¯ pairs, based on a data set corresponding to an integrated luminosity of 2.93 fb-1 collected at the ψ(3770) resonance by the BESIII experiment. The asymmetry between CP-odd and CP-even eigenstate decays into K-π+ is determined to be AKπ=0.132±0.011±0.007, where the first uncertainty is statistical and the second is systematic. This measurement is an update of an earlier study exploiting additional tagging modes, including several decay modes involving a KL0 meson. The branching fractions of the KL0 modes are determined as input to the analysis in a manner that is independent of any strong phase uncertainty. Using the predominantly CP-even tag D→π+π-π0 and the ensemble of CP-odd eigenstate tags, the observable AKππππ0 is measured to be 0.130±0.012±0.008. The two asymmetries are sensitive to rDKπcosδDKπ, where rDKπ and δDKπ are the ratio of amplitudes and phase difference, respectively, between the doubly Cabibbo-suppressed and Cabibbo-favoured decays. In addition, events containing D→K-π+ tagged by D→KS,L0π+π- are studied in bins of phase space of the three-body decays. This analysis has sensitivity to both rDKπcosδDKπ and rDKπsinδDKπ. A fit to AKπ, AKππππ0 and the phase-space distribution of the D→KS,L0π+π- tags yields δDKπ=187.6-9.7+8.9-6.4+5.4∘, where external constraints are applied for rDKπ and other relevant parameters. This is the most precise measurement of δDKπ in quantum-correlated DD¯ decays.

A bstract Using a sample of (10 . 09 ± 0 . 04) × 10 9 J/ψ decays collected with the BESIII detector, partial wave analyses of the decay J / ψ → γ K S 0 K S 0 π 0 are performed within the K S 0 K S 0 π 0 invariant mass region below 1.6 GeV/ c 2 . The covariant tensor amplitude method is used in both mass independent and mass dependent approaches. Both analysis approaches exhibit dominant pseudoscalar and axial vector components, and show good consistency for the other individual components. Furthermore, the mass dependent analysis reveals that the K S 0 K S 0 π 0 invariant mass spectrum for the pseudoscalar component can be well described with two isoscalar resonant states using relativistic Breit-Wigner model, i.e., the η (1405) with a mass of 1391.7 ± 0.7 − 0.3 + 11.3 MeV/ c 2 and a width of 60.8 ± 1.2 − 12.0 + 5.5 MeV, and the η (1475) with a mass of 1507.6 ± 1.6 − 32.2 + 15.5 MeV/ c 2 and a width of 115.8 ± 2.4 − 10.9 + 14.8 MeV. The first and second uncertainties are statistical and systematic, respectively. Alternate models for the pseudoscalar component are also tested, but the description of the K S 0 K S 0 π 0 invariant mass spectrum deteriorates significantly.

A bstract Using 6 . 32 fb − 1 of e + e − collision data collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay D s + → K + π + π − and determine the amplitudes of the various intermediate states. The absolute branching fraction of D s + → K + π + π − is measured to be (6 . 11 ± 0 . 18 stat . ± 0 . 11 syst . ) × 10 − 3 . The branching fractions of the dominant intermediate processes D s + → K + ρ 0 , ρ 0 → π + π − and D s + → K * (892) 0 π + , K * (892) 0 → K + π − are determined to be (1 . 96 ± 0 . 19 stat . ± 0 . 23 syst . ) × 10 − 3 and (1 . 85 ± 0 . 12 stat . ± 0 . 13 syst . ) × 10 − 3 , respectively. The intermediate resonances f 0 (500), f 0 (980), and f 0 (1370) are observed for the first time in this channel.

A bstract A partial wave analysis on the process e + e − → ωπ + π − is performed using 647 pb − 1 of data sample collected by using the BESIII detector operating at the BEPCII storage ring at center-of-mass (c.m.) energies from 2.000 GeV to 3.080 GeV. The Born cross section of the e + e − → ωπ + π − process is measured, with precision improved by a factor of 3 compared to that of previous studies. A structure near 2.25 GeV is observed in the energy-dependent cross sections of e + e − → ωπ + π − and ωπ 0 π 0 with a statistical significance of 7.6 σ , and its determined mass and width are 2232 ± 19 ± 27 MeV /c 2 and 93 ± 53 ± 20 MeV, respectively, where the first and second uncertainties are statistical and systematic, respectively. By analyzing the cross sections of subprocesses e + e − → ωf 0 (500), ωf 0 (980), ωf 0 (1370), ωf 2 (1270), and b 1 (1235) π , a structure, with mass M = 2200 ± 11 ± 17 MeV/ c 2 and width Γ = 74 ± 20 ± 24 MeV, is observed with a combined statistical significance of 7.9 σ . The measured resonance parameters will help to reveal the nature of vector states around 2.25 GeV.

A bstract Based on e + e − collision data collected by the BESIII detector at the BEPCII collider at center-of-mass energies from 2.000 to 3.080 GeV, a partial-wave analysis is performed for the process e + e − → K + K − π 0 . The Born cross section of the process e + e − → K + K − π 0 and its subprocesses e + e − → ϕπ 0 , K *+ (892) K − and K 2 ∗ + (1430) K − are measured. The results for e + e − → K + K − π 0 and ϕπ 0 are consistent with the BaBar measurements and with improved precision. By analyzing the cross sections of the subprocesses e + e − → K *+ (892) K − and K 2 ∗ + (1430) K − , a structure with mass M R = (2190 ± 19 ± 37) MeV/ c 2 and width Γ R = (191 ± 28 ± 60) MeV is observed with a combined statistical significance of 7.1 σ . The measured resonance parameters suggest it can be identified as the ϕ (2170), thus the results provide valuable input to understand the internal nature of this state.