摘要：
This paper employs Mathematica for visualizing electromagnetic fields in circular waveguides, effectively addressing pedagogical challenges related to theoretical abstraction and computational complexity. We first derive the exact solutions for guided modes, then summarize the steps for visualizing electromagnetic fields using Mathematica, propose educational strategies, and showcase simulation results. The Mathematica code is provided, allowing for dynamic parameter adjustment and real-time field change observation. This approach significantly enhances undergraduate students' understanding of electromagnetism through engaging visual and interactive learning experiences.
作者机构：
[Lu, Wangjun; Zhai, Cuilu] Hunan Inst Engn, Dept Maths & Phys, Xiangtan 411104, Peoples R China.;[Liu, Yan; Lu, Wangjun; Yuan, Jibing; Tang, Shiqing; Song, Yaju] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Lu, Wangjun] Zhejiang Univ, Zhejiang Inst Modern Phys, Dept Phys, Hangzhou 310027, Peoples R China.;[Li, Songsong] Nanchang Normal Univ, Coll Phys & Elect Informat, Nanchang 330032, Peoples R China.
通讯机构：
[Shiqing Tang] C;College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
<jats:p>In this paper, we investigate the effect of the Dicke quantum phase transition on the speed of evolution of the system dynamics. At the phase transition point, the symmetry associated with the system parity operator begins to break down. By comparing the magnitudes of the two types of quantum speed limit times, we find that the quantum speed limit time of the system is described by one of the quantum speed limit times, whether in the normal or superradiant phase. We find that, in the normal phase, the strength of the coupling between the optical field and the atoms has little effect on the dynamical evolution speed of the system. However, in the superradiant phase, a stronger atom–photon coupling strength can accelerate the system dynamics’ evolution. Finally, we investigate the effect of the entanglement of the initial state of the system on the speed of evolution of the system dynamics. We find that in the normal phase, the entanglement of the initial state of the system has almost no effect on the system dynamics’ evolution speed. However, in the superradiant phase, larger entanglement of the system can accelerate the evolution of the system dynamics. Furthermore, we verify the above conclusions by the actual evolution of the system.</jats:p>
通讯机构：
[Song, Ya-Ju] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Hunan Prov Appl Basic Res Base Optoelect Informat, Hunan Prov Key Lab Intelligent Informat Proc & Ap, Hengyang 421002, Peoples R China.;Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Quantum Contr, Minist Educ, Changsha 410081, Peoples R China.
关键词：
Tripartite negativity;Quantum entanglement;Quantum measurement process;Coleman-Hepp model
摘要：
Based on the solvable dynamical model for quantum measurement process, we consider three uncoupled particles interacting with their local one-dimensional (1D) spin arrays. Here the 1D spin arrays can be regarded as the local phase decoherence environments for the particles. To demonstrate the dynamics of quantum entanglement among three particles in measuring process, the tripartite negativity is introduced. Our study indicates that the tripartite negativity is determined jointly by the initial states and the dephasing factors for four kinds of initial states, including GHZ-type states, W-type states, Weiner-GHZ states, and Weiner-W states. We find the particle-spin array interaction can destroy the tripartite negativity, and the tripartite negativity is the same for the family of entangled GHZ states or the family of entangled W states. Furthermore, there exists the sudden death of tripartite negativity when the initial states are Weiner-GHZ states or Weiner-W states.
作者机构：
[汪新文; 张慧敏; 刘珂; 刘延] College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang;421002, China;Hunan Provincial Key Laboratory of Intelligent Information Processing and Application, Hengyang;[汪新文] 421002, China<&wdkj&>Hunan Provincial Key Laboratory of Intelligent Information Processing and Application, Hengyang;[汪新文; 张慧敏; 刘珂; 刘延] 421002, China
摘要：
<jats:title>Abstract</jats:title><jats:p>The electron‐transporting material (ETM) is one of the key factors to determine the efficiency and stability of organic light‐emitting diodes (OLEDs). A novel ETM with a “(Acceptor)<jats:sub>n</jats:sub>–Donor–(Acceptor)<jats:sub>n</jats:sub>” (“(A)<jats:sub>n</jats:sub>–D–(A)<jats:sub>n</jats:sub>”) structure, 2,7‐di([2,2′:6′,2″‐terpyridin]‐4′‐yl)‐9,9′‐spirobifluorene (27‐TPSF), is synthesized by combining electron‐withdrawing terpyridine (TPY) moieties and rigid twisted spirobifluorene, in which the TPY moieties facilitate electron transport and injection while the spirobifluorene moiety ensures high triplet energy (<jats:italic>T</jats:italic><jats:sub>1</jats:sub> = 2.5 eV) as well as enhances glass transition temperature (<jats:italic>T</jats:italic><jats:sub>g</jats:sub> = 195 °C) for better stability. By using tris[2‐(<jats:italic>p‐</jats:italic>tolyl)pyridine]iridium(III) (Ir(mppy)<jats:sub>3</jats:sub>) as the emitter, the 27‐TPSF‐based device exhibits a maximum external quantum efficiency (η<jats:sub>ext, max</jats:sub>) of 24.5%, and a half‐life (T<jats:sub>50</jats:sub>) of 121, 6804, and 382 636 h at an initial luminance of 10 000, 1000, and 100 cd m<jats:sup>−2</jats:sup>, respectively, which are much better than the commercialized ETM of 9,10‐bis(6‐phenylpyridin‐3‐yl)anthracene (DPPyA). Furthermore, a higher efficiency, a η<jats:sub>ext, max</jats:sub> of 28.2% and a maximum power efficiency (η<jats:sub>PE</jats:sub>, <jats:sub>max</jats:sub>) of 129.3 lm W<jats:sup>−1</jats:sup>, can be achieved by adopting bis(2‐phenylpyridine)iridium(III)(2,2,6,6‐tetramethylheptane‐3,5‐diketonate) (Ir(ppy)<jats:sub>2</jats:sub>tmd) as the emitter and 27‐TPSF as the ETM. These results indicate that the derivative of TPY to form “(A)<jats:sub>n</jats:sub>–D–(A)<jats:sub>n</jats:sub>” structure is a promising way to design an ETM with good comprehensive properties for OLEDs.</jats:p>
摘要：
The polarization evolution of vector beams (VBs) generated by q-plates is investigated theoretically and experimentally. An analytical model is developed for the VB created by a general quarter-wave q-plate based on vector diffraction theory. It is found that the polarization distribution of VBs varies with position and the value q. In particular, for the incidence of circular polarization, the exit vector vortex beam has polarization states that cover the whole surface of the Poincare sphere, thereby constituting a full Poincare beam. For the incidence of linear polarization, the VB is not cylindrical but specularly symmetric, and exhibits an azimuthal spin splitting. These results are in sharp contrast with those derived by the commonly used model, i.e., regarding the incident light as a plane wave. By implementing q-plates with dielectric metasurfaces, further experiments validate the theoretical results. (C) 2017 Chinese Laser Press
摘要：
Schiff base organotin(IV) complexes C1 similar to C5b have been synthesized via the reaction of the substituted salicylaldehyde-o-aminophenol Schiff base ligands (L1 similar to L3) with the dibenzyltin dichloride, n-butyltin trichloride or dibutyltin oxide, respectively. The complexes have been characterized by IR, UV Vis, 1H NMR, 13C NMR spectra, elemental analysis and the crystal structures have been determined by X-ray diffraction. The anticancer activity of the Schiff base ligand and complexes C1 similar to C5b against five species of cancer cell which are Hela, MCF7, HepG2, Colo205, NCI-H460 were tested respectively, the tests showed that C1 similar to C5b exhibited significant anticancer activity for the cancer cells in comparison with the ligand, and the activity was greater than carboplatin. (C) 2017 Published by Elsevier B.V.
摘要：
Two coordination complexes [Cu(phtpy)(obda)]center dot 2H(2)O (1) and [Cu-4(meophtpy)(4)(mbda)(4)]center dot 4H(2)O (2) [phtpy = 4'-phenyl-2,2':6',2aEuro(3)-terpyridine, meophtpy = 4'-(4-methoxyphenyl)-2,2':6',2aEuro(3)-terpyridine, H(2)obda = 1,2-benzenedicarboxylic acid and H(2)mbda = 1,3-benzenedicarboxylic acid] have been synthesized under hydrothermal conditions and characterized by IR, elemental analysis and X-ray single-crystal diffraction. In complex 1, the Cu(II) atoms are bridged by obda(2-) ligands to give 1D chains with phtpy as a terminal ligand, while a 3D network is constructed by hydrogen bonds and pi-pi interactions. In complex 2, the Cu(II) atoms are coordinated by two meophtpy ligands and also linked by mbda(2-) ligands forming a discrete tetranuclear complex. In this complex also, a 3D network is constructed by hydrogen bonds and pi-pi interactions. The most striking feature of complex 2 is that one meophtpy ligand is almost overlapped upon the next which is seldom found in 2,2':6',2aEuro(3)-terpyridine complexes. The luminescence properties of both complexes 1 and 2 have been investigated.
