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With the enhancement of integration and functionality of high-power electronic devices, heat dissipation has become a critical bottleneck limiting performance improvement. In particular, under high power density conditions, interface thermal resistance has emerged as a prominent factor in overall thermal management. In this paper, the interfacial energy transport characteristics of Si/Ge is investigated based on the Boltzmann Transport Equation (BTE). The quality of interfacial energy transport is analyzed using Boltzmann statistical entropy and the losses that occur at the interface during energy transmission is also explored. The results indicate that the mismatch and high degree of localization of interface phonons increase the irreversible loss of energy phonons during transport across the interface, which leads to a significant entropy increase at the interface. Furthermore, the degree of irreversibility in energy loss is related to the thermal transport pathway; the lower the phonon matching at the interface, the greater the thermal transport resistance and the larger the irreversible loss. This research offers a comprehensive analysis of the irreversibility of energy loss, providing novel theoretical frameworks and research avenues for enhancing energy efficiency in high-power electronic devices. [ABSTRACT FROM AUTHOR]

Monitoring the dynamic behavior of active species and modulating their electronic architecture are crucial for the development of efficient catalysts. Here, a 3D ordered multi‐level porous Ni2P/CeO2 heterojunction catalyst with a “self‐optimization effect” is strategically synthesized for efficient oxygen evolution reaction (OER). This catalyst exhibits a low overpotential of 235 mV at 20 mA cm−2 in 1.0 m KOH. During the OER process, the heterojunction catalyst specifically undergoes a unique phase transition involving the leaching of the P element, which triggers the formation of the PO43−‐NiOOH/CeO2 catalyst with PO43− adsorbed on the surface of the reconstructed product NiOOH/CeO2. Density functional theory calculations reveal that the CeO2 and adsorbed‐PO43− in the self‐optimized structure are essential and minor factors for enhancing catalytic activity, respectively. They collaborate to promote the redistribution of electron density in surface Ni and O, increasing the d/p‐band center difference. This phenomenon results in optimized adsorption/desorption of the key intermediates such as *OOH and improved catalytic performance. Overall, this research highlights the potential of d/p‐band modulation for the rational design of cost‐effective and high‐efficiency electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] A rational design of the structure of catalyst layer (CL) is required for proton exchange membrane fuel cells to attain outstanding performance and excellent stability. It is crucial to have a profound comprehension of the correlations existing between the properties (catalyst ink), network structures of CL and proton exchange membrane fuel cells' performance for the rational design of the structure of CL. This study deeply investigates the effects of a series of alcohol solvents on the properties and network structure of CL. The results demonstrate that the CL aggregates in higher ε solution show smaller particle sizes, and the sulfonic acid groups (∼SO 3 H) tend to extend more outward due to the strong dissociation. A more continuous and homogeneous ionomer distribution around Pt/C aggregates is observed in the CL, which improves the electrochemically active surface area (ECSA) and performance of the electrode. But, the electrode has a poor performance at high current density regions due to the mass transfer resistance. Based on this, a two-step solvent control strategy is proposed to maintain uniform ionomer and aggerates distribution and optimize the mass transfer for CL. The performance of the cell improves from 0.555 V to 0.615 V at 2000 mA·cm−2. [ABSTRACT FROM AUTHOR]

Heterogeneous composites consisting of Bi6Cu2Se3.6Cl0.4O6 and Bi2O2Se are prepared according to the concept of modulation doping. With prominently increased carrier mobility and almost unchanged effective mass, the electrical transport properties are considerably optimized resulting in a peak power factor ≈1.8 µW cm−1 K−2 at 873 K, although the carrier concentration is slightly deteriorated. Meanwhile, the lattice thermal conductivity is lowered to ≈0.62 W m−1 K−1 due to the introduction of the second phase. The modified Self‐consistent Effective Medium Theory is utilized to explain the deeper mechanism of modulation doping. The enhancement of apparent carrier mobility is derived from the highly active phase interfaces as fast carrier transport channels, while the reduced apparent thermal conductivity is ascribed to the existence of thermal resistance at the phase interfaces. Ultimately, an optimized ZT ≈0.23 is obtained at 873 K in Bi6Cu2Se3.6Cl0.4O6 + 13% Bi2O2Se. This research demonstrates the effectiveness of modulation doping for optimizing thermoelectric properties once again, and provides the direct microstructure observation and consistent theoretical model calculation to emphasize the role of interface effects in modulation doping, which should be probably applicable to other thermoelectrics. [ABSTRACT FROM AUTHOR]

Polydimethylsiloxane/silica (PDMS/SiO2) particle-reinforced nanocomposites prepared at the present study are typical viscoelastic materials. Due to the high surface-to-volume ratio of the SiO2 nanoparticles, the interface effects on the overall properties of the nanocomposites cannot be ignored. In order to investigate the interface effects on the viscoelastic properties of the nanocomposites, a multiscale model is established in the present study, combining the molecular dynamics (MD) model of the interface at the nanoscale and the unit cell model of the nanocomposites at the mesoscale. In the MD model of the interface, the viscoelastic properties of the interphase region influenced by the interface are found to be different from that of the pure PDMS matrix and the bulk SiO2. Because the polymer chains subject to different restrictions existing in the interphase region, this region can possess high stiffness and damping properties simultaneously. The interphase parameters can be determined by the inverse multiscale simulation method, taking advantage of both the numerical model and the experimental results. Due to the interface effects, as demonstrated by the unit cell model, the dynamic shear moduli of the nanocomposites can be simultaneously improved by several times to an order of magnitude higher than that of the matrix, in consistent with experimental results. Thus, the mechanism of the interface effects enhancing the viscoelastic properties of the PDMS/SiO2 nanocomposites can be revealed in the present study, which can be useful for the design of viscoelastic nanocomposites with high stiffness and damping properties. [ABSTRACT FROM AUTHOR]

Introduction: Magnetic resonance imaging-linear accelerator radiotherapy is an innovative technology that requires special consideration for secondary electron interactions within the magnetic field, which can alter dose deposition at air–tissue interfaces. As part of ongoing quality assurance and quality improvement of new radiotherapy technologies, the purpose of this study was to evaluate skin dose modelled from the treatment planning systems of a magnetic resonance imaging-linear accelerator and a conventional linear accelerator, and then correlate with in vivo measurements of delivered skin dose from each linear accelerator. Methods: In this prospective cohort study, 37 consecutive glioma patients had treatment planning completed and approved prior to radiotherapy initiation using commercial treatment planning systems: a Monte Carlo-based algorithm for magnetic resonance imaging-linear accelerator or a convolution-based algorithm for conventional linear accelerator. In vivo skin dose was measured using an optically stimulated luminescent dosimeter. Results: Monte Carlo-based magnetic resonance imaging-linear accelerator plans and convolution-based conventional linear accelerator plans had similar dosimetric parameters for target volumes and organs-at-risk. However, magnetic resonance imaging-linear accelerator plans had 1.52 Gy higher mean dose to air cavities (P <.0001) and 1.10 Gy higher mean dose to skin (P <.0001). In vivo skin dose was 14.5% greater for magnetic resonance imaging-linear accelerator treatments (P =.0027), and was more accurately predicted by Monte Carlo-based calculation (ρ = 0.95, P <.0001) versus convolution-based (ρ = 0.80, P =.0096). Conclusion: This is the first prospective dosimetric comparison of glioma patients clinically treated on both magnetic resonance imaging-linear accelerator and conventional linear accelerator. Our findings suggest that skin doses were significantly greater with magnetic resonance imaging-linear accelerator plans but correlated better with in vivo measurements of actual skin dose from delivered treatments. Future magnetic resonance imaging-linear accelerator planning processes are being designed to account for skin dosimetry and treatment delivery. [ABSTRACT FROM AUTHOR]

Complex hydrides, such as LiBH4, are a promising class of ion conductors for all-solid-state batteries, but their application is constrained by low ion mobility at room temperature. Mixing with halides or complex hydride anions, i.e., other complex hydrides, is an effective approach to improving the ionic conductivity. In the present study, we report on the reaction of LiBH4 with LiBF4, resulting in the formation of conductive composites consisting of LiBH4, LiF and lithium closo-borates. It is believed that the in-situ formation of closo-borate related species gives rise to highly conductive interfaces in the decomposed LiBH4 matrix. As a result, the ionic conductivity is improved by orders of magnitude with respect to the Li-ion conductivity of the LiBH4, up to 0.9 × 10−5 S cm−1 at 30 °C. The insights gained in this work show that the incorporation of a second compound is a versatile method to improve the ionic conductivity of complex metal hydrides, opening novel synthesis pathways not limited to conventional substituents. [ABSTRACT FROM AUTHOR]

Strategically engineering electrocatalysts with optimized interfacial electronic architectures and accelerated reaction dynamics is pivotal for augmenting hydrogen generation via alkaline water electrolysis on an industrial scale. Herein, a novel triple-interface heterostructure Ni 3 Se 4 -NiSe 2 -Co 3 O 4 nanoarrays are designed anchored on Ti 3 C 2 T x MXene (Ni 3 Se 4 -NiSe 2 -Co 3 O 4 /MXene) with significant work function difference (ΔΦ) as bifunctional electrocatalysts for water electrolysis. Theoretical calculations combined with experiments uncover the pivotal role of the interface-induced electric field in steering charge redistribution, which in turn modulates the adsorption and desorption kinetics of reaction intermediates. Furthermore, the synergistic interaction between Ni 3 Se 4 -NiSe 2 -Co 3 O 4 and Ti 3 C 2 T x MXene nanosheets endows the hybrids with a large electrochemical surface area, abundantly active sites, and high conductivity. Thus, Ni 3 Se 4 -NiSe 2 -Co 3 O 4 /MXene manifests exceptional catalytic prowess for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In addition, the Ni 3 Se 4 -NiSe 2 -Co 3 O 4 /MXene electrocatalyst in the water electrolyzer delivers excellent performance and maintains commendable stability beyond 100 h of electrocatalytic operation., (© 2024 Wiley‐VCH GmbH.)

Bulk and nanoparticle powders of LaCoO3 (LCO) were synthesized and their magnetic and structural properties were studied using SQUID magnetometry and neutron diffraction. The bulk and large nanoparticles exhibit weak ferromagnetism (FM) below T ≈ 85 K and a crossover from strong to weak antiferromagnetic (AFM) correlations near a transition expressed in the lattice parameters, To≈40 K. This crossover does not occur in the smallest nanoparticles; instead, the magnetic behavior is predominantly ferromagnetic. The amount of FM in the nanoparticles depends on the amount of Co3O4 impurity phase, which induces tensile strain on the LCO lattice. A core-interface model is introduced, with the core region exhibiting the AFM crossover and with FM in the interface region near surfaces and impurity phases.

The performance and scalability of silicon spin qubits depend directly on the value of the conduction band valley splitting (VS). In this work, we investigate the influence of electromagnetic fields and the interface width on the VS of a quantum dot in a Si/SiGe heterostructure. We propose a new three-dimensional theoretical model within the effective mass theory for the calculation of the VS in such heterostructures that takes into account the concentration fluctuation at the interfaces and the lateral confinement. With this model, we predict that the electric field is an important parameter for VS engineering, since it can shift the probability distribution away from small VSs for some interface widths. We also obtain a critical softness of the interfaces in the heterostructure, above which the best option for spin qubits is to consider an interface as wide as possible.

We construct a new spatial finite-difference discretization for a regularized 3D Navier–Stokes–Cahn–Hilliard system of equations. The system can be attributed to phase field type models and describes flows of a viscous compressible isothermal two-component two-phase fluid with surface effects; the potential body force is also taken into account. In the discretization, the main sought functions are defined on one and the same mesh, and an original approximation of the solid wall boundary conditions (homogeneous with the discretization of equations) is suggested. The discretization has an important property of the total energy dissipativity allowing one to eliminate completely the so-called spurious currents. The discrete total mass and component mass conservation laws hold as well, and the discretization is also well-balanced for the equilibrium solutions. To ensure that the concentration C remains within the physically meaningful interval (0, 1), the non-convex part of the Helmholtz free energy is taken in a special logarithmic form (the Flory–Huggins potential). The speed of sound can depend on C that leads to different equilibrium mass densities of the "pure" phases. The results of numerical 3D simulations are also presented including those with a gravitational-type force. The positive role of the relaxation parameter is discussed too. [ABSTRACT FROM AUTHOR]

Hafnia-based ferroelectric (FE) thin films are promising candidates for semiconductor memories. However, a fundamental challenge that persists is the lack of understanding regarding dimensional scaling, including thickness scaling and area scaling, of the functional properties and their heterogeneity in these films. In this work, excellent ferroelectricity and switching endurance are demonstrated in 4 nm-thick Hf 0.5 Zr 0.5 O 2 (HZO) capacitors with molybdenum electrodes in capacitors as small as 65 nm × 45 nm in size. The HZO layer in these capacitors can be crystallized into the ferroelectric orthorhombic phase at the low temperature of 400 °C, making them compatible for back-end-of-line (BEOL) FE memories. With the benefits of thickness scaling, low operation voltage (1.2 V) is achieved with high endurance (>10 10 cycles); however, a significant fatigue regime is noted. We observed that the bottom electrode, rather than the top electrode, plays a dominant role in the thickness scaling of HZO ferroelectric behavior. Furthermore, ultrahigh switched polarization (remanent polarization 2 P r ∼ 108 μC cm -2 ) is observed in some nanoscale devices. This study advances the understanding of dimensional scaling effects in HZO capacitors for high-performance FE memories.

With the continuous miniaturization of electronic devices and the increasing speed of their operation, solving a series of technical issues caused by high power consumption has reached an unprecedented level of difficulty. Fortunately, magnons (the quanta of spin waves), which are the collective precession of spins in quantum magnetic materials, making it possible to replace the role of electrons in modern information applications. In the process of information transmission, nano-sized spin-wave devices do not transport any physical particles; therefore, the corresponding power consumption is extremely low. This review focuses on the emerging developments of the spin-wave materials, tunable effects, and functional devices applications. In the materials front, we summarize the magnetic properties and preparation characteristics of typical insulating single-crystalline garnet films or metallic alloy films, the development of new spin-wave material system is also introduced. Afterward, we introduce the emerging electric control of spin-wave effects originating from the interface transitions, physical or chemical, among these films including, voltage-controlled magnetic anisotropy, magneto-ionic transport, electric spin-torque, and magnon-torque. In the functional devices front, we summarize and elaborate on the low dispassion information processing devices and sensors that are realized based on spin waves.

La2/3Sr1/3MnO3 (LSMO) thin films of various thicknesses (6, 8, 10, 20, and 30 nm), capped by 7 nm‐thick Pt layer, are grown by pulsed laser deposition on SrTiO3 (001) substrates. X‐ray diffraction revealed that LSMO films are (001) oriented. Vibrating sample magnetometer is used to determine the magnetization at saturation and the magnetic dead layer thickness. This latter is around 3.4 nm, significantly thicker compared with the one induced at interfaces of Pt with ferromagnetic transition metals. Microstrip line ferromagnetic resonance (MS‐FMR) is used to extract the gyromagnetic ratio, which is found to increase with LSMO thickness. MS‐FMR revealed that the in‐plane magnetic anisotropy is dominated by a uniaxial contribution for the Pt capped film, whereas the noncapped 10 nm‐thick LSMO layer shows a fourfold anisotropy. Furthermore, the thickness dependence of the effective magnetization reveals the existence of a second‐order perpendicular anisotropy term, which is thickness‐dependent, and of a weak uniaxial interface anisotropy. The Gilbert damping coefficient is found to vary linearly with the inverse of the effective LSMO thickness due to spin pumping leading to relatively low spin mixing conductance of LSMO/Pt interface. [ABSTRACT FROM AUTHOR]

The high‐κ polymer P(VDF‐TrFE‐CFE) is applied in the dielectric layer of a thin film transistor based on graphene, inducing a considerable overall performance improvement compared with conventional SiO2 or ordinary polymer PMMA dielectrics. A systematical study reveals the reason for this improvement to be the strong screening effect on the Coulomb scattering in the dielectric‐semiconductor interface, which originates from the high‐κ value of P(VDF‐TrFE‐CFE). This positive effect is dominant enough to compensate for the adverse effects induced by the application of P(VDF‐TrFE‐CFE), including the large surface roughness and strong phonon scattering. A prototype transistor fabricated on a plastic substrate shows similar superior performance and sustainability upon bending operation, testifying the adaptability of P(VDF‐TrFE‐CFE) in a flexible graphene transistor. This study proposes a high‐κ polymer dielectric that is valid for high‐performing transistors based on 2D semiconductor materials. [ABSTRACT FROM AUTHOR]

Domain switching pathways fundamentally control performance in ferroelectric thin film devices. In epitaxial bismuth ferrite (BiFeO3) films, the domain morphology is known to influence the multiferroic orders. While both striped and mosaic domains have been observed, the origins of the latter have remained unclear. Here, it is shown that domain morphology is defined by the strain profile across the film–substrate interface. In samples with mosaic domains, X‐ray diffraction analysis reveals strong strain gradients, while geometric phase analysis using scanning transmission electron microscopy finds that within 5 nm of the film–substrate interface, the out‐of‐plane strain shows an anomalous dip while the in‐plane strain is constant. Conversely, if uniform strain is maintained across the interface with zero strain gradient, striped domains are formed. Critically, an ex situ thermal treatment, which eliminates the interfacial strain gradient, converts the domains from mosaic to striped. The antiferromagnetic state of the BiFeO3 is also influenced by the domain structure, whereby the mosaic domains disrupt the long‐range spin cycloid. This work demonstrates that atomic scale tuning of interfacial strain gradients is a powerful route to manipulate the global multiferroic orders in epitaxial films. [ABSTRACT FROM AUTHOR]

In this study, the wear resistance of diamond dicing blades can be enhanced by electrodepositing a Ni-graphene coating. We prepared Ni-Gr (graphene)-diamond blades through composite electrodeposition in a nickel electrolyte containing varying concentrations of graphene. The microstructure of the composite coating was investigated using characterization techniques, while the deposition of the Ni-Gr was studied using commercial modeling software, namely the COMSOL® electrochemical module. The primary objective of this study was to investigate the pathways leading to the development of high-quality dicing blades. The results obtained from the COMSOL® simulations unveil the influence of graphene particles and cathode conditions on the microstructure and performance of the composite coating. Our experimental results demonstrate that the incorporation of graphene induces modifications in the texture of the Ni matrix, resulting in the emergence of a noncoherent phase boundary. This effect can be attributed to the preferential formation of nucleation sites at heterogeneous interfaces, which were facilitated by the embedding of graphene, resulting in non-uniform nucleation. Furthermore, to explore the mechanical properties of said noncoherent phase boundary, graphene electrodes were prepared using discharge plasma sintering, resulting in, a pure 20 μm thick Ni coating electrodeposited onto the graphene electrode. Micro-nano testing techniques using different peak loads at 25 °C were employed to analyze the mechanical behavior of the graphene substrate, Ni-Gr interface, and Ni phase. Nanoindentation testing revealed an interface adhesion strength of 12.89 N between the graphene substrate and the Ni coating. Indentation experiments in the Ni-Gr interface demonstrated that the elastic moduli of the interface were 23.91 GPa and 28.72 GPa at 20 mN and 300 mN loads, respectively. Additionally, the elastic moduli of the graphene phase was approximately between 6.25 % and 5.56 % that of the Ni phase. [Display omitted] • Diamond and graphene tailored Ni matrix nanocomposite coatings were electroplated. • The incoherent phase boundary formed between Ni and graphene play vital role in microstructure. • Graphene particle distorted electric field lines to control grain growth direction. • Heterogeneous nucleation and current density concentrated on graphene led to alterations in texture orientation. • COMSOL simulation reflected the electroplating condition distorted by cathode rotation. [ABSTRACT FROM AUTHOR]

The huge increase in the superconducting transition temperature of FeSe induced by an interface to SrTiO3 remains unexplained to date. However, there are numerous indications of the critical importance of specific features of the FeSe band topology in the vicinity of the Fermi surface. Here, we explore how the electronic structure of FeSe changes when located on another lattice matched substrate, namely a Si(001) surface, by first-principles calculations based on the density functional theory. We study non-magnetic (NM) and checkerboard anti-ferromagnetic (AFM) magnetic orders in FeSe and determine which interface arrangement is preferred. Our calculations reveal interesting effects of Si proximity on the FeSe band structure. Bands corresponding to hole pockets at the Γ point in NM FeSe are generally pushed down below the Fermi level, except for one band responsible for a small remaining hole pocket. Bands forming electron pockets centered at the M point of the Brillouin zone become less dispersive, and one of them is strongly hybridized with Si. We explain these changes by a redistribution of electrons between different Fe 3d orbitals rather than charge transfer to/from Si, and we also notice an associated loss of degeneracy between dxz and dyz orbitals.

The physical aging behavior, time‐dependent densification, of thin polystyrene (PS) films supported on silicon are investigated using ellipsometry for a large range of molecular weights (MWs) from Mw = 97 to 10,100 kg mol−1. We report an unexpected MW dependence to the physical aging rate of h < 80‐nm thick films not present in bulk films, where samples made from ultra‐high MWs ≥ 6500 kg mol−1 exhibit on average a 45% faster aging response at an aging temperature of 40 °C compared with equivalent films made from (merely) high MWs ≤ 3500 kg mol−1. This MW‐dependent difference in physical aging response indicates that the breadth of the gradient in dynamics originating from the free surface in these thin films is diminished for films of ultra‐high MW PS. In contrast, measures of the film‐average glass transition temperature Tg(h) and effective average film density (molecular packing) show no corresponding change for the same range of film thicknesses, suggesting physical aging may be more sensitive to differences in dynamical gradients. These results contribute to growing literature reports signaling that chain connectivity and entropy play a subtle, but important role in how glassy dynamics are propagated from interfaces. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 1224–1238 [ABSTRACT FROM AUTHOR]

Ni-based amorphous transition metal catalysts have gained considerable research attention owing to their superior alkaline oxygen evolution performance compared to their crystalline counterparts. In this work, we prepared amorphous NiFe/graphene composites via the solvothermal method. By regulating the ratio of components, the composite catalyst exhibited an exceptionally low overpotential of 231 mV at a current density of 10 mA cm−2 and maintained stable catalytic behavior for 100 h at this current density. Electrochemical analysis and differential charge density diagrams revealed the presence of charge transport at the interface of the heterogeneous structure, greatly increasing the intrinsic activity of the material. Additionally, pH dependence on the catalytic activity suggested a decoupled proton-electron transfer (PT/ET) pathway, and chemical deprotonation is identified as the rate-limiting step in the catalytic reaction. These findings provide critical insights and reliable data to facilitate future research on improving the oxygen evolution performance of NiFe-based amorphous catalysts. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • MoC films on different substrates, identical sheet resistance – similar disorder. • Difference in superconducting T c and spectral smearing Γ. • Tunneling spectra of Dynes superconductors, lower T c accompanied by higher Γ. • Film-substrate interface induced pair-breaking. Abstract Many disordered superconducting films exhibit smeared tunneling spectra with evident in-gap states. We have found that the tunneling density of states in ultrathin MoC films is gapless and can be described by the Dynes version of the BCS density of states with a strong broadening parameter Γ accounting for the suppression of coherence peaks and increased in-gap states. The thinner the film, the lower the T c and the superconducting energy gap Δ and the larger the Γ. MoC films of 3 nm thickness deposited simultaneously on silicon and sapphire substrates reveal very similar scalar disorder, evidenced by the equal sheet resistance, but exhibit different superconducting characteristics of T c , Δ and Γ, suggesting that pair breaking responsible for the dissipation channel and the suppression of superconductivity originates on the film-substrate interface. It indicates that sapphire is a stronger pair breaker. Interface pair breaking can be operative in other cases as well. [ABSTRACT FROM AUTHOR]

Highlights • Effective properties of micropolar nanocomposite with interface effect. • Interface assumed to resist stretching and bending. • Influence of flexural resistance of interface on effective properties. • New model of the micropolar interface. Graphical abstract Variations of the effective shear modulus ratio with radius of the void for Type I surface in Case 2 boundary conditions (left). Variations of the effective shear modulus ratio with radius of the void for Type II surface in Case 2 boundary conditions (right). Image, graphical abstract Abstract We consider the effective shear and bulk moduli of a micropolar nano-composite in which the interface between individual constituents incorporates intrinsic micropolar elastic properties associated with both extensibility and flexural stiffness. Specifically, we are concerned with the representative problem describing plane deformations of an inhomogeneity-matrix composite in which a circular inhomogeneity is embedded in an infinite micropolar material subjected to arbitrary remote loading. Our main interest lies in the additional contribution of interfacial bending and twisting rigidities to the interface effect and how each influences the mechanical properties of the composite. Using a model of the micropolar interface established in a previous paper by the authors, we present an analytical solution of the problem using two Airy-type stress potentials. This solution is then used to calculate the effective shear and bulk moduli of the corresponding nano-composite with special attention paid to the flexural resistance of the interface and its influence on the size-dependency of the effective moduli. We note also as a check of our results that, in the absence of interfacial flexural rigidity, our solution recovers precisely the results in the literature presented for the effective moduli of a micropolar composite whose interface effect incorporates only membrane type resistance. [ABSTRACT FROM AUTHOR]

Abstract The understanding of the formation and movement of charges inside solid polymer electrolytes is a critical point of the research for the development of better lithium-ion batteries (LIBs). In order to facilitate the understanding of the charge distributions, the Kelvin probe force microscopy with a reliable statistical data analysis approach has been used. As poly(ethylene oxide) (PEO) is a material used as an electrolyte in LIBs, the PEO and its salt compound with lithium perchlorate (LiClO 4) were investigated with this approach. The transient formation and movement of internal potential and simultaneously the charge distribution were investigated with respect to time under biased and unbiased conditions. [ABSTRACT FROM AUTHOR]

Abstract The sensitive online detection technique for heavy metal ions present in ocean, while effectively eliminating the interference of other chemicals, has been lacking at the present time. We found that the interfacial barrier of ZnO/rGO/PPy heterostructure had powerful physical effects on electrochemistry, and the Schottky barrier driven electrochemical detection was further developed. As based on the interfacial physical barrier, it could avoid the existing problem of the traditional electrochemical sensing mechanism and apply in more interfering environment. The sensitive detection of trace mercury ion (Hg2+) in actual seawater was achieved by employing the ZnO/rGO/PPy heterostructure. The interfacial barrier effect provides a chance to develop sensors used in more interfering environment. Highlights • The interfacial barrier of ZnO/rGO/PPy heterostructure had powerful physical effects on electrochemistry. • The interfacial barrier driven electrochemical detection was developed. • The sensitive detection of trace Hg2+ in actual seawater was achieved. [ABSTRACT FROM AUTHOR]

This paper presents a hierarchical multiscale simulation framework for investigating the interface effects in polymer nanocomposites. In this framework, the load transfer ability of the interface in carbon nanotube (CNT)-epoxy nanocomposites is evaluated using molecular dynamics (MD) simulations by adopting an atomistic graphene-polymer interface model in which the cured epoxy matrix with various crosslink densities is constructed by using a dynamic crosslinking algorithm. The interfacial behavior between CNTs and the epoxy matrix has been characterized in both normal opening mode and sliding mode separation in terms of the force-separation responses at the nanoscale. Key factors, e.g. the crosslink density of the epoxy network in the matrix, the system temperature, the separation mode and functionalization, has been investigated on their effects on the load transfer ability of the CNT-epoxy interface. Further, by employing embedded cohesive zone model in finite element analysis, the macroscale effective material properties of the CNT-epoxy nanocomposites have been evaluated under the nanoscale interface effects. It is observed that covalent functionalization between CNT and polymer matrix can dramatically improve the load transfer ability of the interface at the nanocale, thereby enhancing the effective mechanical properties of the nanocomposites at the microscale. This work will assist in deepening our knowledge about the load transfer ability of the interface and the corresponding strengthening mechanisms in CNT reinforced epoxy nanocomposites. [ABSTRACT FROM AUTHOR]

Highlights • Distribution of configurational forces in a non-uniform bar in tension. • Two illustrative development routes to obtain an analytical solution. • Implementation into open-source FEM framework OpenGeoSys. • Code and examples available for extension. Abstract The concept of material or configurational forces, albeit not new, is one of those innovations in theoretical mechanics that has struggled to reach the success of wide-spread acceptance, or even familiarity. Perhaps, one reason for this is to be found in the few available introductory examples or in the non-trivial physical-mathematical approach often taken to establish this concept, although by no means more complex than other treatments in non-linear continuum mechanics. With this work we aim at contributing to the dissemination of configurational mechanics concepts by guiding the reader through an introductory analytical example step by step and comparing it to numerically obtained results. The numerical model is solved with OpenGeoSys (OGS-6), an open-source, C++-based, object-oriented finite element platform for the thermo-hydro-mechanical analysis of coupled processes in fractured porous media. In the spirit of the open-source philosophy, and to enable the readers to reproduce the example themselves, both the source code and the input files are available online. The example highlights—in a simple and intuitive manner—several insightful aspects related to configurational mechanics. [ABSTRACT FROM AUTHOR]

Superconductivity at the two-dimensional limit in crystalline films with only one unit cell thick or one quantum well channel has become a frontier in the field of superconductivity. In this paper, we briefly review the recent experimental detections of superconductivity at the two-dimensional limit and corresponding Berezinskii-Kosterlitz-Thouless (BKT) transitions using imaging, spectroscopy and transport techniques, such as one-monolayer Pb/In films on Si(lll) substrates, one-unit-cell FeSe films on SrTiO3 (001) substrates, and two-monolayer Ga films on GaN(0001) substrates. Due to anisotropy, quantum size effects from dimension limitation, and interface effects between the film and the substrate, superconducting parameters such as critical temperature, Bardeen-Cooper-Schrieffer (BCS) ratio and critical magnetic fields in thin films can be significantly different from those in corresponding bulk materials. Furthermore, considering quasi-two-dimensional layered structure in high-Tc superconductors and dissipation problem in electronic integrated circuits, the investigation of superconductivity at the two-dimensional limit is expected not only to reveal new physical phenomena or properties, but also to further understand high-Tc superconductivity and explore new high-Tc superconductors, as well as to develop new generation of dissipationless electronic devices and low-dissipation integrated circuits. [ABSTRACT FROM AUTHOR]

This paper deals with the universal model describing plane strain bending of a multilayered sector of a cylindrical tube which can have residual deformations as well as nano-scale effects. In order to model the response of the sector at the nano-scale, the Gurtin-Murdoch theory is employed. Residual deformations of the layers, such as prestretch or precompression, are introduced into the model of finite bending using the multiplicative decomposition rule for corresponding deformation gradients. Numerous coupled nonlinear effects exhibited by the sector are discussed. [ABSTRACT FROM AUTHOR]

In the mechanical analysis of composites containing nano-inhomogeneities, it is customary to consider only the stretching resistance of the inhomogeneity-matrix interface but neglect the bending resistance of the interface. In this paper, we consider a circular nano-inhomogeneity in an infinite elastic plane subjected to an arbitrary uniform remote in-plane loading with both stretching and bending resistance incorporated on the interface. Analytic solutions are obtained for the stress field both inside and outside the inhomogeneity by using an integral-type boundary condition representing the jump in traction across the interface. We show that the presence of interface bending resistance has no influence on the average of the mean stress in the inhomogeneity, and for certain interface stretching and bending rigidities the stress field inside the inhomogeneity can remain uniform regardless of the specific uniform remote loading. Numerical examples are presented to examine the influence of the interface bending resistance on the interfacial tractions imposed on the inhomogeneity and matrix for a uniform remote uniaxial loading. It is found that the introduction of interface bending resistance perturbs the (interfacial) tractions imposed on the inhomogeneity only slightly whether the inhomogeneity is softer or harder than the matrix, while it may influence the (interfacial) tractions imposed on the matrix significantly when the inhomogeneity is much softer than the matrix. Moreover, it is shown that the peak of the interface bending resistance-induced jump in traction across the interface initially increases and then decreases as the inhomogeneity becomes harder (from an initial state in which the inhomogeneity is softer than the matrix). [ABSTRACT FROM AUTHOR]

The catalytic activity for the oxygen reduction reaction (ORR) of a hexagonal boron nitride (h-BN) monolayer deposited on a Au(111) surface and decorated by a small planar Au8 cluster has been studied theoretically using density-functional theory. It is shown that gold nanoparticles (Au-NP) deposited on the h-BN/Au(111) surface can provide catalytically active sites for effective ORR at the perimeter interface with the support. Stabilization of oxygen at the perimeter interface between Au-NP and h-BN/Au(111) support promotes OOH* dissociation opening effective 4-electron pathway of ORR with formation of H2O. It is suggested that increase in the perimeter interface area between the supported Au-NP and the surface would result in increase of the ORR activity. Such increase in the perimeter interface area can be achieved by decreasing the size of Au-NP. Our calculations demonstrate the principal ability to functionalize inert materials such as stand-alone h-BN monolayer or Au surface for the ORR and open new way to design effective Pt-free catalysts for fuel cell technology.? [ABSTRACT FROM AUTHOR]

The crystal structure of the interfacial areas of a δ-FCC water-quenched nano-hydride was characterized by electron energy-loss spectroscopy (EELS) and electron diffraction. EELS revealed ribbons with plasmon energy (PE) values of 17.4 ± 0.01 eV and 18.3 ± 0.01 eV (nominally characteristic of the ζ- and γ-hydride phases, respectively) in the interfacial area between the δ-core and α-Zr matrix. Electron diffraction patterns (DPs) obtained from the <2 1 ¯ 1 ¯ 0> axes of the interface contained reflections that could be indexed as {0001} reflections of the ζ-phase. Such ζ-type reflections, however, disappeared after tilting the interface away from the <2 1 ¯ 1 ¯ 0>-axes; implying that they originated from sources other than a hypothetical ζ-phase. Moreover, electron DPs obtained from multiple zone axes of the interface, did not show characteristic {110}/{112} superlattice reflections of the γ-phase. These results ruled out the existence of ζ- and γ-phases in the interface (down to the spatial resolution of the utilized techniques) despite the measured plasmon energy values. Subsequently, dielectric theory was utilized to clarify the origin of interfacial ribbons with PE values characteristic of the ζ- and γ-phases. Dielectric functions of the α-Zr and δ-core were extracted from the energy-loss spectra of the two phases, to simulate the energy-loss functions across the interface. Simulations suggested that the observed interfacial ribbons in EELS maps (with PE values of 17.4 ± 0.01 eV and 18.3 ± 0.01 eV) could have stemmed from the delocalized nature of plasmon vibration and the effect of interface on shifting the plasmon vibration frequency, but not necessarily from the existence of the ζ- and γ-phases. [Display omitted] a) The crystal structure of tip and side segments of the interface area between a δ-hydride precipitate in α-Zr matrix was characterized. While experimental plasmon energy (PE) maps showed interfacial ribbons with characteristic PE values of intermediate ζ- and γ-hydride phases in both tip and flat sides of the interface, nano-beam electron diffraction patterns obtained from three zone axes of the interface did not confirm existence of the ζ- and γ-phases in the interface. b) Dielectric theory was utilized to simulate the plasmon energy behavior of areas across the interface. Simulations suggest that the observed interfacial PE values are likely due to a natural shift in PE values of the δ-hydride and α-Zr, caused by the interface effect combined with the delocalized nature of plasmon vibration in the 16–20 eV energy-loss window of interest [ABSTRACT FROM AUTHOR]

• The promoting effect of atom doping on CO 2 methanolization over Cu/ZnO based catalyst is studied using DFT method. • Cu-ZnO heterostructure improves the fromate pathway of CO 2 hydrogenation by MSI (metal-support interaction). • The scaling relationships between adsorption energies with the correlation coefficients R 2 ≈ 0.8 are extracted. • The performance of various metal promoters is ranked as Al > Ga > Mg, Pt > Pd > Au. The usage of CO 2 , a vital carbon source, is of great application value in carbon neutrality. Hydrogenation is one of the most promising approaches to convert the CO 2 into high-value chemicals like methanol. The development of the hydrogenation of CO 2 mainly lies in the design of safe and efficient catalysts. Focusing on the mechanism and the interface effects, the hydrogenation of CO 2 to methanol over Cu/ZnO-based catalyst was investigated in this work. To study the enhancing effect of metal promoters, atomic doping was simulated on Cu/ZnO-X(Al,Mg,Ga,Pt,Pd,Au) catalyst. Based on the designed atomic doped mode, density functional theory (DFT) calculation was conducted to analyze the adsorption of intermediates, thermodynamic reaction path, and kinetics of CO 2 methanolization. The results show that Cu-ZnO heterostructure improves the HCOO path of CO 2 hydrogenation by metal-support interaction (MSI). A linear relationship between the adsorption energy of the intermediates via hydrogenation process was found with the correlation coefficient R 2 ≈ 0.8. The order of the highest activation barriers for the overall reaction is Cu/ZnO-Au > Cu/ZnO-Mg > Cu/ZnO-Pd > Cu/ZnO-Pt > Cu/ZnO-Ga > Cu/ZnO > Cu/ZnO-Al. The diverse performance of various metal promoters was ranked as Al > Ga > Mg, Pt > Pd > Au. Our simulation work well corresponds the previous experimental results conducted by other scholars and will provide guidance for future design of the high-efficient catalysis for CO 2 hydrogenation. [ABSTRACT FROM AUTHOR]

In this paper we present the atomic-layer-by-layer oxide molecular beam epitaxy (ALL-oxide MBE) which has been recently installed in the Max-Planck Institute for Solid State Research and we report on its present status, providing some examples that demonstrate its successful application in the synthesis of different layered oxides, with particular reference to superconducting La2CuO4 and insulator-to-metal La2−xSrxNiO4. We briefly review the ALL-oxide MBE technique and its unique capabilities in the deposition of atomically smooth single-crystal thin films of various complex oxides, artificial compounds and heterostructures, introducing our goal of pursuing a deep investigation of such systems with particular emphasis on structural defects, with the aim of tailoring their functional properties by precise defects control.

The governing equation of screw dislocations in heterostructures is constructed using image method. The interface type (-1 ≤ γ ≤ 1) and distance between dislocation and interface h are considered in the new equation. The Peierls-Nabarro equations for screw dislocations in bulk and semi-infinite materials can be recovered when γ = 0 and γ = -1. The soft (γ < 0) and hard (γ > 0) interfaces can enhance and reduce the Peierls stress of screw dislocations near the interface, respectively. The interface effects on dislocations decrease with the increasing of distance h. The Al/TiC heterostructure is investigated as a model interface to study the unstable stacking fault energy and dislocation properties of the interface. The mismatch of lattice constants and shear modulus at the interface results in changes of the unstable stacking fault energy. Then, the changes of the unstable stacking fault energy also have an important effect on dislocation properties, comparing with γ and h. [ABSTRACT FROM AUTHOR]

Purpose Hypofractionated partial breast irradiation ( HPBI) involves treatment to the breast tumor using high doses per fraction. Recent advances in MRI-Linac solutions have potential in being applied to HPBI due to gains in the soft tissue contrast of MRI; however, there are potentially deleterious effects of the magnetic field on the dose distribution. The purpose of this work is to determine the effects of the magnetic field on the dose distribution for HPBI tumors using a tangential beam arrangement ( TAN), 5-beam intensity-modulated radiation therapy ( IMRT), and volumetric modulated arc therapy ( VMAT). Methods Five patients who have received HPBI were selected with two patients having bilateral disease resulting in a total of two tumors in this study. Six planning configurations were created using a treatment planning system capable of modeling magnetic field dose effects: TAN, IMRT and VMAT beam geometries, each of these optimized with and without a transverse magnetic field of 1.5 T. Results The heart and lung doses were not statistically significant when comparing plan configurations. The magnetic field had a demonstrated effect on skin dose: for VMAT plans, the skin (defined to a depth of 3 mm) D1cc was elevated by +11% and the V30 by +146%; for IMRT plans, the skin D1cc was increased by +18% and the V30 by +149%. Increasing the number of beam angles (e.g., going from IMRT to VMAT) with the magnetic field on reduced the skin dose. Conclusion The impact of a magnetic field on HPBI dose distributions was analyzed. The heart and lung doses had clinically negligible effects caused by the magnetic field. The magnetic field increases the skin dose; however, this can be mitigated by increasing the number of beam angles. [ABSTRACT FROM AUTHOR]

The propagation of evanescent waves in hybrid poroelastic metamaterials is investigated by considering interface effects. Hybrid metamaterials consist of a single-phased (acoustic or elastic) medium and a poroelastic medium. To establish the finite element model of elastic/poroelastic and fluid/poroelastic interfaces, weak integral forms of wave equations for elastic, fluid, and poroelastic media and boundary conditions at the interfaces between different media are first given. Next, the expressions for displacement and pressure in the frame of Bloch's theorem are substituted into the dynamical equations to obtain general forms suitable for periodic metamaterials, from which the complex band structure and the frequency response of hybrid metamaterials are calculated. The influence of geometrical and material parameters, as well as the viscosity of the pore fluid on the propagation of elastic waves are discussed. The results and discussions show that flat bands and narrow locally resonant band gaps appear for elastic/poroelastic metamaterials. A quasi-resonance Bragg band gap is formed in the case of an elastic inclusion in a poroelastic matrix. Furthermore, a transition from an avoided crossing to a wave-number band gap is obtained by adjusting the geometrical and material parameters of the elastic inclusion. For the case of fluid inclusion in a poroelastic matrix with the open-pore interface, a cut-off frequency for the fast longitudinal wave is observed. However, only an avoided crossing is produced for the sealed-pore interface. For both cases, the phase velocity of the shear vertical (SV) wave decreases faster than that of the slow longitudinal wave as the radius of the inclusion increases. When the viscosity of the pore fluid is considered for elastic inclusion in a poroelastic matrix, the transmission dip at the 'quasi-resonance Bragg' band gap disappears. However, the transmission dip in the locally resonant band gap of the SV wave becomes slightly shallower and smoother than in the inviscid case. This study is relevant to practical applications of hybrid single-phased and poroelastic metamaterials, e.g., for coastal engineering and civil engineering. [Display omitted] • Wave propagation in hybrid multi-phase metamaterials is investigated. • Interface conditions for multi-phase media are extended to periodic and lossy cases. • A quasi-resonant Bragg band gap is seen for an elastic inclusion in a porous matrix. • A transition from avoid-crossing to wave-number band gap is found in the P/E system. [ABSTRACT FROM AUTHOR]

• Electrical responses and elastic properties are obtained for the hybrid graphene/CNT/elastomer-based nanocomposites. • The applied pressure under bending of the hybrid composites causes significant reduction of electrical resistance and percolation threshold. • Pressure-dependent volume fractions of graphene, CNT and polymer are established. • Electric resistance decreased over several orders of magnitude for graphene/CNT/THV elastomer sensors as the bending pressure increases from 0 to 1 KPa. • This makes the hybrid nanocomposite a very sensitive pressure sensor. The hybrid graphene/carbon nanotube (CNT)/elastomer nanocomposite is studied as a pressure sensor under bending. The main idea is that, due to the uneven elastic deformation between the softer elastomer matrix and the stiffer nanofillers, the volume fractions of graphene and CNTs both increase as a result of bending, and this in turn triggers higher electrical conductivity and superb sensing performance of the nanocomposite. This effect is analyzed through a three-phase composite model that contains graphene nanoplatelets (GNPs) and CNTs in a fluorinated elastomer matrix. We also show how the elastic and electrical properties of the hybrid nanocomposite depend on the graphene and CNT volume fractions. It is demonstrated that, with the increase of bending pressure from 0 to 1 KPa, the sensor resistance reduced by several orders of magnitude, which makes the hybrid sensor conductive from an insulator and an ideal pressure sensor. [ABSTRACT FROM AUTHOR]

The performance of electrical equipment and devices is determined to a great extent by the properties of their insulating materials. In power systems and electrical devices, insulating materials have to work in extreme circumstances that can include high temperature differences, intense radiation, and strong electric fields. Such conditions demand high-quality insulating materials with superior electrical, thermal, and mechanical properties as well as resilience to other environmental stresses. This study focuses on advances in insulating materials since the early 20th century and reviews the many developments in their properties and applications, including electric breakdown strength, thermal conductivity, temperature resistance, corona resistance, and specific energy storage in dielectrics. Some research progress on other properties is also covered, such as non-linearity and radiation resistance. Investigations into the properties of insulating materials can greatly assist in understanding their interface effects and composite structures, which in turn is helpful for discovering methods to improve the performance of electrical devices. Future directions for research are proposed to guide new investigations and support the development of even better insulating materials.