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<jats:p>We consider the SU(3) spin–orbit coupled spin-1 Bose–Einstein condensates in a two-dimensional harmonic trap. The competition between the SU(3) spin–orbit coupling and the spin-exchange interaction results in a rich variety of lattice configurations. The ground-state phase diagram spanned by the isotropic SU(3) spin–orbit coupling and the spin–spin interaction is presented. Five ground-state phases can be identified on the phase diagram, including the plane wave phase, the stripe phase, the kagome lattice phase, the stripe-honeycomb lattice phase, and the honeycomb hexagonal lattice phase. The system undergoes a sequence of phase transitions from the rectangular lattice phase to the honeycomb hexagonal lattice phase, and to the triangular lattice phase in spin-1 Bose–Einstein condensates with anisotrpic SU(3) spin–orbit coupling.</jats:p>

<jats:p>The physical characterization of a colloidal system of superficially modified magnetic nanoparticles (MNPs) is presented. The system consists of oleic acid-coated iron oxide nanoparticles (OAMNP) suspended in water. A structural analysis is carried out by using standard physical techniques to determine the diameter and shape of the MNPs and also the width of the coating shell. The colloidal stability and the polydispersity index of this ferrofluid are determined by using Zeta potential measurements. Additionally, the magnetic characterization is conducted by obtaining the DC magnetization loops, and the blocking temperatures are determined according to the ZFC–FC protocol. Finally, the values of power absorption density <jats:italic>P</jats:italic> of the ferrofluid are estimated by using a magneto-calorimetric procedure in a wide range of magnetic field amplitude <jats:italic>H</jats:italic> and frequency <jats:italic>f</jats:italic>. The experimental results exhibit spherical-like shape of OAMNP with (20 ± 4) nm in diameter. Due to the use of coating process, the parameters of the magnetization loops and the blocking temperatures are significantly modified. Hence, while the uncoated MNPs show a blocking state of the magnetization, the OAMNP are superparamagnetic above room temperature (300 K). Furthermore, the reached dependence <jats:italic>P versus f</jats:italic> and <jats:italic>P versus H</jats:italic> of the ferrofluid with coated MNPs are clearly fitted to linear and quadratic correlations, respectively, showing their accordance with the linear response theory.</jats:p>

<jats:p>We design an electromechanical transducer harvesting system with one-to-one internal resonance that can emerge a broader spectrum vibrations. The novel harvester is composed of a Duffing electrical circuit coupled to a mobile rod, and the coupling between both components is realized via the electromagnetic force. Approximate analytical solutions of the electromechanical system are carried out by introducing the multiple scales analysis, also the nonlinear modulation equation for one-to-one internal resonance is obtained. The character of broadband harvesting performance are analyzed, the two peaks and one jump phenomenon bending to the right for variation of control parameters are observed. It is shown that an advanced bandwidth over a corresponding linear model that does not possess a modal energy interchange.</jats:p>

<jats:p>Dynamic nature of hydrogen bond (H-bond) is central in molecular science of substance transportation, energy transfer, and phase transition in H-bonding networks diversely expressed as solution, crystal, and interfacial systems, thus attracting the state-of-the-art revealing of its phenomenological edges and sophisticated causes. However, the current understanding of the ground-state fluctuation from zero-point vibration (ZPV) lacks a firm quasi-classical base, concerning three basic dimensions as geometry, electronic structure, and interaction energy. Here, based on the <jats:italic>ab initio</jats:italic> molecular dynamics simulation of a ground-state water dimer, temporally separated fluctuation features in the elementary H-bond as the long-time weakening and the minor short-time strengthening are respectively assigned to two low-frequency intermolecular ZPV modes and two O–H stretching ones. Geometrically, the former modes instantaneously lengthen H-bond up to 0.2 Å whose time-averaged effect coverages to about 0.03 Å over 1-picosecond. Electronic-structure fluctuation crosses criteria’ borders, dividing into partially covalent and noncovalent H-bonding established for equilibrium models, with a 370% amplitude and the district trend in interaction energy fluctuation compared with conventional dragging models using frozen monomers. Extended physical picture within the normal-mode disclosure further approaches to the dynamic nature of H-bond and better supports the upper-building explorations towards ultrafast and mode-specific manipulation.</jats:p>

<jats:p>Boron carbide (B<jats:sub>4</jats:sub>C) is a rhombic structure composed of icosahedra and atomic chains, which has an important application in armored materials. The application of B<jats:sub>4</jats:sub>C under super high pressure without failure is a hot spot of research. Previous studies have unmasked the essential cause of B<jats:sub>4</jats:sub>C failure, <jats:italic>i.e.</jats:italic>, its structure will change subjected to impact, especially under the non-hydrostatic pressure and shear stress. However, the change of structure has not been clearly understood nor accurately determined. Here in this paper, we propose several B<jats:sub>4</jats:sub>C polymorphs including B<jats:sub>4</jats:sub>C high pressure phases with non-icosahedra, which are denoted as post-B<jats:sub>4</jats:sub>C and their structures are formed due to icosahedra broken and may be obtained through high pressure and high temperature (HPHT). The research of their physical properties indicates that these B<jats:sub>4</jats:sub>C polymorphs have outstanding mechanical and electrical properties. For instance, aP10, mC10, mP20, and oP10-B<jats:sub>4</jats:sub>C are conductive superhard materials. We hope that our research will enrich the cognition of high pressure structural deformation of B<jats:sub>4</jats:sub>C and broaden the application scope of B<jats:sub>4</jats:sub>C.</jats:p>

<jats:p>We execute the density functional theory (DFT) and time-dependent density functional theory (TDDFT) approaches to make a detailed exploration about excited state luminescent properties as well as excited state intramolecular proton transfer (ESIPT) mechanism for the novel 2,6-dimethyl phenyl (DMP-HBT-py) system. Firstly, we check and confirm the formation and stabilization of hydrogen bonding interaction for DMP-HBT-py. Via optimized geometrical parameters of primary chemical bond and infrared (IR) spectra, we find O–H⋯N hydrogen bond of DMP-HBT-py should be strengthened in S<jats:sub>1</jats:sub> state. Insights into frontier molecular orbitals (MOs) analyses, we infer charge redistribution and charge transfer (ICT) phenomena motivate ESIPT trend. Via probing into potential energy curves (PECs) in related electronic states, we come up with the ultrafast ESIPT behavior due to low potential barrier. Furthermore, we search the reaction transition state (TS) structure, the ultrafast ESIPT behavior and mechanism of DMP-HBT-py compound can be re-confirmed. We sincerely wish this work could play roles in further developing novel applications based on DMP-HBT-py compound and in promoting efficient solid emitters in OLEDs in future.</jats:p>

<jats:p>The three-component Gross–Pitaevskii equation with an angular momentum rotational term can be served as a model to study spinor Bose–Einstein condensates (BECs) with time–space modulated interactions. Vortex solutions of the spinor BECs with spatiotemporally modulated interactions are worked out by similarity transformation. Theoretical analysis and numerical simulation of vortex states are demonstrated. Stable vortex states are obtained by adjusting the frequency of the external potential and the spatiotemporally modulated interaction.</jats:p>

<jats:p>We propose a metal/dielectric tri-layer metamaterial for wavefront shaping. By arranging the element in an array with a constant phase gradient and irradiated it with a plane wave, focused and focused vortex beams can be obtained. The designed metamaterial features the excellent capability of focused/focused vortex beams generation within the operating frequency range of 30 GHz–34 GHz. The simulation results are consistent with the theoretical analyses.</jats:p>

<jats:p>Annular-focused beams have attracted attention because of their novel properties and applications in optical trapping, high resolution microscopy, and laser-induced periodic surface structuring. Generation of this beam is very important and necessary. In this article, a novel design of zone plate for forming the annular-focused beams is proposed. The design principle is introduced, and the characteristics of zone plate are analyzed by numerical simulation. The result shows that the zone plate can form a monochromatic ring-shaped intensity distribution in the focal plane. And the design method is also generally suitable for designing the other optical elements to generate the annular-focused beams.</jats:p>

<jats:p>Instrument drifts introduce additional phase errors into atmospheric wind measurement of Doppler asymmetric spatial heterodyne spectroscopy (DASH). Aiming at the phase sensitivity of DASH to instrument drifts, in this paper we calculate the optical path difference (OPD) and present an accurate formula of DASH interferogram. By controlling variables in computational ray-tracing simulations and laboratory experiments, it is indicated that initial phase is directly determined by incident wavenumber, OPD offset and field of view (FOV). Accordingly, it is indicated that retrieved phase of DASH is sensitive to slight structural change caused by instrument drift, which provides the proof of necessary-to-track and -correct phase errors from instrument drifts.</jats:p>