The D→ρD\to \rho semileptonic and radiative decays within the light-cone sum rules

The measured branching ratio of the $D$ meson semileptonic decay $D \to \rho e^+ \nu_e$, which is based on the $0.82~{\rm fb^{-1}}$ CLEO data taken at the peak of $\psi(3770)$ resonance, disagrees with the traditional SVZ sum rules analysis by about three times. In the paper, we show that this discrepancy can be eliminated by applying the QCD light-cone sum rules (LCSR) approach to calculate the $D\to \rho$ transition form factors $A_{1,2}(q^2)$ and $V(q^2)$. After extrapolating the LCSR predictions of these TFFs to whole $q^2$-region, we obtain $1/|V_{\rm cd}|^2 \times \Gamma(D \to \rho e \nu_e) =(55.45^{+13.34}_{-9.41})\times 10^{-15}~{\rm GeV}$. Using the CKM matrix element and the $D^0(D^+)$ lifetime from the Particle Data Group, we obtain ${\cal B} (D^0\to \rho^- e^+ \nu_e) = (1.749^{+0.421}_{-0.297}\pm 0.006)\times 10^{-3}$ and ${\cal B} (D^+ \to \rho^0 e^+ \nu_e) = (2.217^{+0.534}_{-0.376}\pm 0.015)\times 10^{-3}$, which agree with the CLEO measurements within errors. We also calculate the branching ratios of the two $D$ meson radiative processes and obtain ${\cal B}(D^0\to \rho^0 \gamma)= (1.744^{+0.598}_{-0.704})\times 10^{-5}$ and ${\cal B}(D^+ \to \rho^+ \gamma) = (5.034^{+0.939}_{-0.958})\times 10^{-5}$, which also agree with the Belle measurements within errors. Thus we think the LCSR approach is applicable for dealing with the $D$ meson decays.Comment: 12 pages, 7 figures, version to be published in EPJ

3-(4-Meth­oxy­benzyl­idene)-1,5-dioxa­spiro­[5.5]undecane-2,4-dione

In the title mol­ecule, C17H18O5, which was prepared by the reaction of (R)-1,5-dioxaspiro­[5.5]undecane-2,4-dione and 4-meth­oxy­benzaldehyde with ethanol, the 1,3-dioxane ring is in a distorted envelope conformation with the spiro C atom forming the flap. The crystal structure is stabilized by weak inter­molecular C—H⋯O hydrogen bonds

A pyrene-armed hexahomotrioxacalix[3]arene as a multi-sensor via synergistic and demetallation effects

A new pyrene-armed hexahomotrioxacalix[3]arene L has been synthesized, which exhibits a pronounced fluorescence enhancement response toward Cu²⁺ ions via a Zn²⁺ or Cd²⁺ triggered synergistic effect. Additionally, the L·Cu²⁺+ complex can subsequently serve as a sensor for F⁻ via anion-induced demetallation. The fluorescence responses by the input of Cu²⁺, Zn²⁺/Cd²⁺ and F⁻ can be constructed as a combinational logic gate which mimics a set of molecular traffic signals

Are humorous frontline employees hotels’ secret weapons? Investigating when and why employee sense of humor promotes service performance

Despite the growing efforts devoted to exploring humor, the extant humor literature neglects the impact of employee sense of humor in the workplace, especially in the hospitality industry, an important yet understudied context. Based on person–environment fit theory, our research examines why and when employee sense of humor can influence frontline hospitality employees’ service performance. Our multi-wave research of 232 frontline hospitality employees in two Chinese hotels unveils that employee sense of humor promotes service performance by enhancing person–service job fit. Moreover, customer contact frequency strengthens the direct impact of employee sense of humor on person–service job fit and the indirect effect of employee sense of humor on service performance through person–service job fit. Our research underlines the pivotal role of humorous frontline employees in hospitality organizations

A pyrene-functionalized triazole-linked hexahomotrioxacalix[3]arene as a fluorescent chemosensor for Zn²⁺ ions

A new pyrenyl appended hexahomotrioxacalix[3]arene L featuring 1,2,3-triazole linkers was synthesized as a fluorescent chemosensor for Zn²⁺ in mixed aqueous media. It exhibited high affinity toward Zn²⁺, and the monomer and excimer emission of the pyrene moieties could be adjusted. The binding stoichiometry of the L·Zn²⁺ complex was determined to be 1:1, and the association constant (Ka) was found to be 7.05 × 10⁴ M⁻¹. The binding behavior with Zn²⁺ has been confirmed by ¹H NMR spectroscopic analysis

Portable Intelligent Oscilloscope Based on Innovative Education

Based on the innovative education idea that students in various universities can do experiments anytime and anywhere without being limited by the course time, a portable oscilloscope suitable for students' experiment and teaching practice is designed by using Arduino, Android and Bluetooth Technology. This oscilloscope not only realizes the basic functions of an oscilloscope, but also makes the measurement images of low-frequency signals more clear and impressive. In addition, the design based on the mobile App is more user-friendly, which enhances the user's sense of use and facilitates the sorting and query of experimental data. The application test shows that the oscilloscope has stable performance, clear waveform, satisfies students' learning and teaching practice to a large extent, and has a good development prospect

Perceptions of negative workplace gossip:a self-consistency theory framework

We present and test a self-consistency theory framework for gossip: that perceived negative workplace gossip influences our self-perceptions and, in turn, this influences our behaviors. Using supervisor-subordinate dyadic time-lagged data (n = 403), we demonstrated that perceived negative workplace gossip adversely influenced target employees’ organization-based self-esteem, which, in turn, influenced their citizenship behavior directed at the organization and at its members. Moreover, by integrating victimization theory into our framework, we further demonstrated that negative affectivity, an individual’s dispositional tendency, not only moderated the self-consistency process but also predicted perceived negative workplace gossip. Our study therefore shifts attention to the target of negative workplace gossip and in doing so offers a promising new direction for future research. Implications to theory and practice are discussed