The difficulty in the decay constants and spectra of DsJ∗D^{*}_{sJ}

We examine the compatibility in predicted masses and the decay constants of $D^{*}_{sJ}$ mesons in terms of two-quark contents. We find that the results of a specific model, which is governed by heavy quark limit, will encounter a challenge to fit both spectra and decay constants simultaneously.Comment: 4 pages, 1 figure, Revtex4, to appear in Mod. Phys. Lett.

Improper Ferroelectric Polarisation in a Perovskite driven by Inter-site Charge Transfer and Ordering

It is of great interest to design and make materials in which ferroelectric polarisation is coupled to other order parameters such as lattice, magnetic and electronic instabilities. Such materials will be invaluable in next-generation data storage devices. Recently, remarkable progress has been made in understanding improper ferroelectric coupling mechanisms that arise from lattice and magnetic instabilities. However, although theoretically predicted, a compact lattice coupling between electronic and ferroelectric (polar) instabilities has yet to be realised. Here we report detailed crystallographic studies of a novel perovskite Hg$^{\textbf{A}}$Mn$^{\textbf{A'}}_{3}$Mn$^{\textbf{B}}_{4}$O$_{12}$ that is found to exhibit a polar ground state on account of such couplings that arise from charge and orbital ordering on both the A' and B-sites, which are themselves driven by a highly unusual Mn$^{A'}$-Mn$^B$ inter-site charge transfer. The inherent coupling of polar, charge, orbital and hence magnetic degrees of freedom, make this a system of great fundamental interest, and demonstrating ferroelectric switching in this and a host of recently reported hybrid improper ferroelectrics remains a substantial challenge.Comment: 9 pages, 7 figure

Stationary Light Pulses in Cold Atomic Media

Stationary light pulses (SLPs), i.e., light pulses without motion, are formed via the retrieval of stored probe pulses with two counter-propagating coupling fields. We show that there exist non-negligible hybrid Raman excitations in media of cold atoms that prohibit the SLP formation. We experimentally demonstrate a method to suppress these Raman excitations and realize SLPs in laser-cooled atoms. Our work opens the way to SLP studies in cold as well as in stationary atoms and provides a new avenue to low-light-level nonlinear optics.Comment: 4 pages, 4 figure

The Evaluation And Using Intention For Digital Teaching Materials Of Penghu Basalt

The Bureau of Culture of Penghu County produced the Penghu Basalt Digital Teaching Materials, which are supplementary teaching materials for local curriculums in elementary and middle schools in Penghu County. But just what are the teachers’ and students’ opinions of the said teaching materials? Are they willing to use them? Are they suitable? These questions are, indeed, worth further research. The questionnaire survey was conducted to gather the opinions of 142 teachers and 151 students of elementary and middle schools in Penghu County. In addition, using the quasi-experimental and experimental teaching methods, after comparing the pre-test and post-test results to the control group, the learning effectiveness was determined. The results indicate that teachers and students have the highest evaluation for the interface design aspect of this teaching material. The teachers’ evaluation for the teaching materials is significantly higher than the students’. Furthermore, the teaching materials are evaluated highly in terms of attracting attention, generating interest and willingness to use, indicating that the digital teaching materials have potential for promotion in Penghu. After the experimental teaching, only the vocational high school students’ scores before and after the experiment showed significantly improvement, while the scores of the students in the other levels of schools did not. &nbsp

Effects of Quality of Financial Statements and CEO Turnover

The purpose of this study is to explore the effect of CEO turnover and CFO turnover on earnings management. In addition, Taiwan’s authorities will require listed companies to complete the establishment of audit committee replacing supervisors in 2022. Corporate governance is not an overnight phenomenon. It has been existing from a long time. It is only that the beginning of 21st century when colossal enterprises started to fall, government across globe started giving it due credit. The present paper is an attempt to trace the history of corporate governance. It starts with discussing various theories which led to the development of such an important concept and then dwells on various models in which economies employ corporate governance in their structure and finally the evolution of corporate governance across globe. The paper sheds light on important committees and reforms which have been the genesis of corporate governance across globe. It undertakes an extensive literature review on different aspects of corporate governance. Corporate governance is a concept which still debatable among experts in describing it. The purpose of this study is to explore how the implementation and principal problems of good corporate governance in the management of current limited liability company