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<jats:p>Exact analytical equations and computations for the longitudinal and transverse acoustic radiation force and axial torque components for a lossless eccentric liquid cylinder submerged in a nonviscous fluid and insonified by plane waves progressive waves (of arbitrary incidence in the polar plane) are established and computed numerically. The modal matching method and the translational addition theorem in cylindrical coordinates are used to derive exact mathematical expressions applicable to any inner and outer cylinder sizes without any approximations, and taking into account the interaction effects between the waves propagating in the layer and those scattered from the cylindrical core. The results show that longitudinal and transverse radiation force components arise, in addition to the emergence of an axial radiation torque component acting on the non-absorptive compound cylinder due to geometrical asymmetry as the eccentricity increases. The computations demonstrate that the axial torque component, which arises due to a geometrical asymmetry, can be positive (causing counter-clockwise rotation in the polar plane), negative (clockwise rotation) or neutral (rotation cancellation) depending on the size parameter of the cylinder and the amount of eccentricity. Furthermore, verification and validation of the results have been accomplished from the standpoint of energy conservation law applied to scattering, and based on the reciprocity theorem.</jats:p>

<jats:p>We present new lemmas, theorem and corollaries to construct interactions among higher-order rogue waves, <jats:italic>n</jats:italic>-periodic waves and <jats:italic>n</jats:italic>-solitons solutions (<jats:italic>n</jats:italic> → ∞) to the (2+1)-dimensional asymmetric Nizhnik–Novikov–Veselov (ANNV) equation. Several examples for theories are given by choosing definite interactions of the wave solutions for the model. In particular, we exhibit dynamical interactions between a rogue and a cross bright-dark bell wave, a rogue and a cross-bright bell wave, a rogue and a one-, two-, three-, four-periodic wave. In addition, we also present multi-types interactions between a rogue and a periodic cross-bright bell wave, a rogue and a periodic cross-bright-bark bell wave. Finally, we physically explain such interaction solutions of the model in the 3D and density plots.</jats:p>

<jats:p>The turbulence governed by the Navier–Stokes equation is paramount in many physical processes. However, it has been considered as a challenging problem due to its inherent nonlinearity, non-equilibrium, and complexity. Herein, we review the connections between the velocity derivative skewness <jats:italic>S<jats:sub>k</jats:sub> </jats:italic> and the non-equilibrium properties of turbulence. <jats:italic>S<jats:sub>k</jats:sub> </jats:italic>, a reasonable candidate for describing the non-equilibrium turbulence, which varies during the non-equilibrium procedure. A lot of experimental or numerical evidences have shown that the perturbation of energy spectrum, which associated with the excitation of large scales, results in an obvious variation of <jats:italic>S<jats:sub>k</jats:sub> </jats:italic>, and <jats:italic>S<jats:sub>k</jats:sub> </jats:italic> is a negative value in this rapid energy decay process. The variation of positive <jats:italic>S<jats:sub>k</jats:sub> </jats:italic> is closely related to the perturbation of transfer spectrum, and this corresponds to the backward energy transfer process. In addition, the skewness characterizes the production (or reduction) rate of enstrophy due to vortex stretching (or compression). Using the transport equation of turbulent energy dissipation rate and enstrophy, it is possible to establish a theoretical connection between skewness and the non-equilibrium turbulence. It is expected that this work could trigger the rapid advancement of the future studies of non-equilibrium turbulence, and also the improvement of turbulence models.</jats:p>

<jats:p>Bell–Plesset (BP) effect caused perturbation growth plays an important role in better understanding of characteristics of the convergence effect. Governing equations for multi-mode perturbation growth on a cylindrically convergent interface are derived. The second-order weakly nonlinear (WN) solutions for two-mode perturbations at the interface which is subject to uniformly radical motion are obtained. Our WN theory is consistent with the numerical result in terms of mode-coupling effect in converging Richtmyer–Meshkov instability. Nonlinear mode-coupling effects will cause irregular deformation of the convergent interface. The mode-coupling behavior in convergent geometry depends on the mode number, Atwood number <jats:italic>A</jats:italic> and convergence ratio <jats:italic>C</jats:italic> <jats:sub>r</jats:sub>. The <jats:italic>A</jats:italic> = –1.0 at the interface results in larger perturbation growth than <jats:italic>A</jats:italic> = 1.0. The growth of generated perturbation modes from two similar modes at the initial stage are smaller than that from two dissimilar modes.</jats:p>

<jats:p>Tensile behaviors of Ti/Ni nanolaminate with model-I crack are investigated by molecular dynamics simulations. The Ti/Ni nanolaminates with center crack either in Ti layer or in Ni layer under different loading directions are utilized to systematically study the mechanical performance of the cracked material. The results indicate that pre-existing crack dramatically changes the plastic deformation mechanism of the Ti/Ni nanolaminate. Unlike the initial plastic deformation originating from the interface or weak Ti layer of the crack-free samples, the plastic behavior of cracked Ti/Ni nanolaminate first occurs at the crack tip due to the local stress concentration. Subsequent plastic deformation is dominated by the interaction between the crack and interface. The Ti/Ni interface not only impedes the movement of the initial plastic deformation carriers (dislocation, slip band, and deformation twinning) from the crack tip, but also promotes the movement of interfacial dislocations in the tension process. Microstructure evolution analysis further confirms that the plastic deformation mechanism transition is ascribed to the orientation-dependent tensile behavior at the crack tip, which is intrinsically attributed to the anisotropy of the certain crystal structure and loading direction of the cracked Ti/Ni nanolaminate. In addition, by analyzing the effects of different plastic deformation carriers on crack propagation in specific crystal, it can be discovered that the interfacial dislocations moving towards the crack tip can further promote the crack growth.</jats:p>

<jats:p>The detailed understanding of various underlying processes at liquid/solid interfaces requires the development of interface-sensitive and high-resolution experimental techniques with atomic precision. In this perspective, we review the recent advances in studying the liquid/solid interfaces at atomic level by electrochemical scanning tunneling microscope (EC-STM), non-contact atomic force microscopy (NC-AFM), and surface-sensitive vibrational spectroscopies. Different from the ultrahigh vacuum and cryogenic experiments, these techniques are all operated <jats:italic>in situ</jats:italic> under ambient condition, making the measurements close to the native state of the liquid/solid interface. In the end, we present some perspectives on emerging techniques, which can defeat the limitation of existing imaging and spectroscopic methods in the characterization of liquid/solid interfaces.</jats:p>

<jats:p>Water is ubiquitous and so is its presence in the proximity of surfaces. To determine and control the properties of interfacial water molecules at nanoscale is essential for its successful applications in environmental and energy-related fields. It is very challenging to explore the atomic structure and electronic properties of water under various conditions, especially at the surfaces. Here we review recent progress and open challenges in describing physicochemical properties of water on surfaces for solar water splitting, water corrosion, and desalination using first-principles approaches, and highlight the key role of these methods in understanding the complex electronic and dynamic interplay between water and surfaces. We aim at showing the importance of unraveling fundamental mechanisms and providing physical insights into the behavior of water on surfaces, in order to pave the way to water-related material design.</jats:p>

<jats:p>The dynamic recombination of two triplet excitons with opposite spins in the heterojunction structure has been investigated using a nonadiabatic evolution method. We demonstrate that luminous composite states including the excited polaron and the biexciton can be formed efficiently via the triplet exciton–triplet exciton reaction in the heterojunction and therefore this reaction can enhance the electroluminescence efficiency considerably, which is consistent qualitatively with experimental observations. Meanwhile, we find that, although the heterojunctions are beneficial to the generation of luminescent particles, large band offset caused by the heterojunction structure is not helpful to improve the electroluminescence efficiency. In addition, the mechanism of the triplet exciton–triplet exciton reaction in heterojunction is different from that of two similar coupling chains. Our results may deepen the understanding of the electroluminescence mechanism in polymer light-emitting devices.</jats:p>

<jats:p>We demonstrate two short-wavelength infrared avalanche photodiodes based on InAs/GaSb superlattice grown by metal-organic chemical vapor deposition. The difference between the two devices, namely, p<jats:sup>+</jats:sup>n<jats:sup>−</jats:sup>n<jats:sup>+</jats:sup> and p<jats:sup>+</jats:sup>nn<jats:sup>−</jats:sup>n<jats:sup>+</jats:sup>, is that the p<jats:sup>+</jats:sup>nn<jats:sup>−</jats:sup>n<jats:sup>+</jats:sup> device possesses an additional middle-doped layer to separate the multiplication region from the absorption region. By properly controlling the electric field distribution in the p<jats:sup>+</jats:sup>nn<jats:sup>−</jats:sup>n<jats:sup>+</jats:sup> device, an electric field of 906 kV/cm has been achieved, which is 2.6 times higher than that in the p<jats:sup>+</jats:sup>n<jats:sup>−</jats:sup>n<jats:sup>+</jats:sup> device. At a reverse bias of –0.1 V at 77 K, both devices show a 100% cut-off wavelength of 2.25 μm. The p<jats:sup>+</jats:sup>n<jats:sup>−</jats:sup>n<jats:sup>+</jats:sup> and p<jats:sup>+</jats:sup>nn<jats:sup>−</jats:sup>n<jats:sup>+</jats:sup> show a dark current density of 1.5 × 10<jats:sup>−7</jats:sup> A/cm<jats:sup>2</jats:sup> and 1.8 × 10<jats:sup>−8</jats:sup> A/cm<jats:sup>2</jats:sup>, and a peak responsivity about 0.35 A/W and 0.40 A/W at 1.5 μm, respectively. A maximum multiplication gain of 55 is achieved in the p<jats:sup>+</jats:sup>nn<jats:sup>−</jats:sup>n<jats:sup>+</jats:sup> device while the value is only less than 2 in the p<jats:sup>+</jats:sup>n<jats:sup>−</jats:sup>n<jats:sup>+</jats:sup> device. Exponential nature of the gain characteristic as a function of reverse bias confirms a single carrier hole dominated impact ionization.</jats:p>