The Influence of Energy Transfer on the Color Temperature Change in Color-Tunable Organic Light Emitting Diodes with Interface Exciplex

The color-tunable white organic light-emitting diode (CT-WOLED) with wide correlation color temperature (CCT) has many advantages in optimizing the artificial light source to adapt to the human physiological cycle. The research on the change trend of CCT and the law of extending the change range of CCT will help to further improve the performance of this kind of device. The present work fabricated a series of CT-WOLED devices with a simple structure, which are all composed of two ultra-thin phosphor layers (PO-01 and Flrpic) and a spacer interlayer. The yellow interface exciplex (TCTA/PO-T2T) formed between the spacer layer (PO-T2T) and transmission material (TCTA) in EML will decrease the CCT value at low voltage. The relationship between the energy transfer in EML and CCT change trend is investigated by adjusting the interface exciplexes and the thickness of the interlayer or the phosphor layer in devices A, B and C, respectively. The results demonstrate that a simple OLED device with an interlayer inserted between two ultra-thin phosphor layers can achieve a wider CCT span from 3359 K to 6451 K at voltage increases from 2.75 V to 8.25 V. .

In situ formed LiF-Li_(3)N interface layer enables ultra-stable sulfide electrolyte-based all-solid-state lithium batteries

Sulfide solid electrolytes are promising for high energy density and safety in all-solid-state batteries due to their high ionic conductivity and good mechanical properties.However,the application of sulfide solid electrolytes in all-solid-state batteries with lithium anode is restricted by the side reactions at lithium/electrolytes interfaces and the growth of lithium dendrite caused by nonuniform lithium deposition.Herein,a homogeneous LiF-Li_(3)N composite protective layer is in situ formed via a manipulated reaction of pentafluorobenzamide with Li metal.The LiF-Li_(3)N layer with both high interfacial energy and interfacial adhesion energy can synergistically suppress side reactions and inhibit the growth of lithium dendrite,achieving uniform deposition of lithium.The critical current densities of Li_(10)GeP_(2)S_(12)and Li_(6)PS_(5)Cl are increased to 3.25 and 1.25 mA cm^(-2)with Li@LiF-Li_(3)N layer,which are almost triple and twice as those of Li-symmetric cells in the absence of protection layer,respectively.Moreover,the Li@LiF-Li_(3)N/Li10GeP2S12/Li@LiF-Li_(3)N cell can stably cycle for 9000 h at 0.1 mA cm^(-2)under 0.1 mA h cm^(-2),and Li@LiF-Li_(3)N/Li_(6)PS_(5)Cl/Li@LiF-Li_(3)N cell achieves stable Li plating/stripping for 8000 h at 0.1 mA cm^(-2)under10 m A h cm^(-2).The improved dynamic stability of lithium plating/stripping in Li@LiF-Li_(3)N/Li_(10)GeP_(2)S_(12)or Li_(6)PS_(5)Cl interfaces is proved by three-electrode cells.As a result,LiCoO_(2)/electrolytes/Li@LiF-Li_(3)N batteries with Li_(10)GeP_(2)S_(12)and Li_(6)PS_(5)Cl exhibit remarkable cycling stability of 500 cycles with capacity retentions of 93.5%and 89.2%at 1 C,respectively.

Mathematical Modelling of Particle Movement Ahead of the Solid-liquid Interface in Continuous Casting

Whether the particle will be trapped by the solid-liquid interface or not is dependent on its moving behavior ahead of the interface, so a mathematical model has been developed to investigate the movement of the particle ahead of the solid-liquid interface. Based on the theory for the boundary layer, the fluid velocity field near the solid-liquid interface was obtained, and the trajectories of particles were calculated by the equations of motion for particles. In this model, the drag force, the added mass force, the buoyance force, the gravitational force, the Saffman force and the Basset history force are considered. The results show that the behavior of the particle ahead of the solid-liquid interface is affected by the physical property of the particle and fluid flow. And in the continuous casting process, if it moves in the stream directed upward or downward near vertical solid-liquid interface or in the horizontal flow under the solid-liquid interface, the particle with the diameter from 5 um to 60um can reach the solid-liquid interface. But if it moves in horizontal flow above the solid-liquid interface, only the particle with the diameter from 5 um to 10 um can reach the solid-liquid interface.

Fast charge transport motivated by tunable Mo2C/Mo2N high-quality heterointerface for superior pseudocapacitive storage

The development of potential transition-metal carbide/nitride heterojunctions is hindered by overall understanding and precise modulation for heterointerface effects.Herein,we demonstrate that Mo_(2)C/Mo_(2)N heterojunction with the precisely regulated high-quality interface can achieve marvelous rate performance and energy output via enlarging the interface-effect range and maximizing "accelerated charge" amount The heterointerface mechanism improving properties is synergistically revealed from kinetics and thermodynamics perspectives.Kinetics analysis confirms that the self-built electric field affords a robust force to drive rapid interface electrons/ions migration.The small adsorption energy,high density of states and quite low diffusion barrier thermodynamically enhance the electrochemical reaction dynamics on heterointerface.Consequently,the almost optimal performance of ultrahigh capacitance retention(85.6% even at 10 A g^(-1)) and pronounced energy output(96.4 Wh kg^(-1))in hybridsupercapacitors than other Mo_(2)C/Mo_(2)N-based materials is presented.This work gives new insight into the energy storage mechanism of heterojunction and guides the design of advanced electrodes.

Molecular Dynamics Simulation of Interface Properties between Water-Based Inorganic Zinc Silicate Coating Modified by Organosilicone and Iron Substrate

The interface properties of Fe(101)/zinc silicate modified by organo-siloxane(KH-570)was studied by using the method of molecular dynamics simulation.By calculating the temperature and energy fluctuation of equilibrium state,equilibrium concentration distribution,MSD of layer and different groups,and interaction energy of two interface models,the influencing mechanism on the interface properties of adding organosiloxane into coating system was studied at the atomic scale.It shows that the temperature and energy of interface oscillated in a small range and it was exited in a state of dynamic equilibrium within the initial simulation stage(t<20 ps).It can be seen from the multiple peak states of concentration distribution that the iron substrate,organo-siloxane and zinc silicate are distributed in the form of a concentration gradient in the real environment.The rapid diffusion of free zinc powder in zinc silicate coating was the essential reason that affected the comprehensive properties of coating.The interface thickness decreased from 7.45 to 6.82Å,the MSD of free zinc powder was effectively reduced,and the interfacial energy was increased from 104.667 to 347.158 kcal/mol after being modified by organo-siloxane.

A review of nonlinear piezoelectric energy harvesting interface circuits in discrete components

Piezoelectric energy harvesting is considered as an ideal power resource for low-power consumption gadgets in vibrational environments.The energy extraction efficiency depends highly on the interface circuit,and should be highly improved to meet the power requirements.The nonlinear interface circuits in discrete components have been extensively explored and developed with the advantages of easy implementation,stable operation,high efficiency,and low cost.This paper reviews the state-of-the-art progress of nonlinear piezoelectric energy harvesting interface circuits in discrete components.First,the working principles and the advantages/disadvantages of four classical interface circuits are described.Then,the improved circuits based on the four typical circuits and other types of circuits are introduced in detail,and the advantages/disadvantages,output power,efficiency,energy consumption,and practicability of these circuits are analyzed.Finally,the future development trends of nonlinear piezoelectric energy harvesting circuits,e.g.,self-powered extraction,low-power consumption,and broadband characteristic,are predicted.

Application of wavelet packet decomposition and its energy spectrum on the coal-rock interface identification

The theory and method of wavelet packet decomposition and its energy spectrum dealing with the coal rock Interface Identification are presented in the paper. The characteristic frequency band of the coal rock signal could be identified by wavelet packet decomposition and its energy spectrum conveniently, at the same time, quantification analysis were performed. The result demonstrates that this method is more advantageous and of practical value than traditional Fourier analysis method.

Influence of laser energy input mode on joint interface characteristics in laser brazing with Cu-base filler metal

The flange butt joints of 1 mm-thick galvanized steel sheets were brazed with CuSi3 as filler metal at different laser heating modes.The microstructures and element distributions of joint interface were investigated by SEM and EDS.The results show that there is no obvious interface layer with the circular individual beam heating and lamellar Fe-Si intermetallic compound layer is found with dual-beam laser spot heating.With the irradiation of rectangular laser spot,the joint interface layer is also formed.The layer thickness is larger than that of dual-beam brazing and the layer shape is flat so that intermetallic compounds trend to grow into cellular crystals.Moreover,the interface layer shape also depends on its position in the joint.Under the high heat input,dendritic or granular intermetallic compounds dispersively distribute in brazing seam adjacent to the interface,which is caused by the melting or dissolving of the base metal.According to the results,the brazing quality can be controlled by laser heating mode and processing parameters.

Energy Storage Systems Technologies, Evolution and Applications

Energy in its varied forms and applications has become the main driver of today’s modern society. However, recent changes in power demand and climatic changes (decarbonization policy) has awakened the need to rethink through the current energy generating and distribution system. This led to the exploration of other energy sources of which renewable energy (like thermal, solar and wind energy) is fast becoming an integral part of most energy system. However, this innovative and promising energy source is highly unreliable in maintaining a constant peak power that matches demand. Energy storage systems have thus been highlighted as a solution in managing such imbalances and maintaining the stability of supply. Energy storage technologies absorb and store energy, and release it on demand. This includes gravitational potential energy (pumped hydroelectric), chemical energy (batteries), kinetic energy (flywheels or compressed air), and energy in the form of electrical (capacitors) and magnetic fields. This paper provides a detailed and comprehensive overview of some of the state-of-the-art energy storage technologies, its evolution, classification, and comparison along with various area of applications. Also highlighted in this paper is a plethora of power electronic Interface technologies that plays a significant role in enabling optimum performance and utilization of energy storage systems in different areas of application.

Apparent Active Adsorption Force at a Solid-Liquid Interface with Active Adsorption

The paper presents a new relationship between the three surface tensions on the solid-liquid-vapor interface, γ_(sl)-γ_(sv)+γ_(lv)cosθ=βin order to understand the wetting on the liquid-solid interface in the case of active adsorption.The authors suggest a new force“apparent active adsorption force”βto take part in the balance at the three interface lines of contact in the solid-liquid-vapor phases,its dimen- sion isβ=Σα_iRT(Γ_i^(sl)-Γ_i^(sv)+Γ_i^(lv)cosθ),and its direction is dependent on the sign of β,whenβis a positive, the direction is agree with surface tension of the sol- id-vapor interface γ and vice versa.

The effect of interfacial energy anisotropy on planar interface instability in a succinonitrile alloy under a small temperature gradient

The morphological stability of a planar interface with different crystallographic orientations is studied under a small positive temperature gradient using a transparent model alloy of succinonitrile. Novel experimental apparatus is constructed to provide a temperature gradient of about 0.37 K/mm. Under this small temperature gradient, the planar interface instability depends largely on the crystallographic orientation. It is shown experimentally that the effect of interfacial energy anisotropy on planar interface stability cannot be neglected even in a small temperature gradient system. Higher interfacial energy anisotropy leads the planar interface to become more unstable, which is different from the stabilizing effect of the interfacial energy on the planar interface. The experimental results are in agreement with previous theoretical calculations and phase field simulations.

ELASTO-PLASTIC BRANCHED ANALYSIS FOR AN INTERFACE CRACK BASED ON CRACK ENERGY DENSITY

The elasto-plastic finite element analyses for an interface crack in dissimilar material, based on the crack energy density (CED) concept, are investigated in mode I loading condition. It is confirmed that the values of CED almost remain stable when the notch radius rho is sufficiently small, both in elastic and elasto-plastic case. Numerical results for both elastic and elasto-plastic cases show that under the mode I loading condition, when the crack propagates to the more stiff material with a small angle, the total CED will become larger than that along the interface. If the clack heads into the more compliant material, the CED will become less than that along the interface.

A numerical study of coupled maps representing energy exchange processes between two environmental interfaces regarded as biophysical complex systems

The field of environmental sciences is abundant with various interfaces and is the right place for the application of new fundamental approaches leading towards a better understanding of environmental phenomena. Following the definition of environmental interface by Mihailovic and Bala? [1], such interface can be, for example, placed between: human or animal bodies and surrounding air, aquatic species and water and air around them, and natural or artificially built surfaces (vegetation, ice, snow, barren soil, water, urban communities) and the atmosphere, cells and surrounding environment, etc. Complex environmental interface systems are (i) open and hierarchically organised (ii) interactions between their constituent parts are nonlinear, and (iii) their interaction with the surrounding environment is noisy. These systems are therefore very sensitive to initial conditions, deterministic external perturbations and random fluctuations always present in nature. The study of noisy non-equilibrium processes is fundamental for modelling the dynamics of environmental interface regarded as biophysical complex system and for understanding the mechanisms of spatio-temporal pattern formation in contemporary environmental sciences. In this paper we will investigate an aspect of dynamics of energy flow based on the energy balance equation. The energy exchange between interacting environmen- tal interfaces regarded as biophysical complex systems can be represented by coupled maps. Therefore, we will numerically investigate coupled maps representing that exchange. In ana- lysis of behaviour of these maps we applied Lyapunov exponent and cross sample entropy.

Interaction energy of interface dislocation loops in piezoelectric bi-crystals

Interface dislocations may dramatically change the electric properties, such as polarization, of the piezoelectric crystals. In this paper, we study the linear interactions of two interface dislocation loops with arbitrary shape in generally anisotropic piezoelectric bi-crystals. A simple formula for calculating the interaction energy of the interface dislocation loops is derived and given by a double line integral along two closed dislocation curves. Particularly, interactions between two straight segments of the interface dislocations are solved analytically, which can be applied to approximate any curved loop so that an analytical solution can be also achieved. Numerical results show the influence of the bi-crystal interface as well as the material orientation on the interaction of interface dislocation loops.

Effect of current density on distribution coefficient of solute at solid-liquid interface

When current passes through the solid-liquid interface, the growth rate of crystal, solid-liquid interface energy and radius of curvature at dendritic tip will change. Based on this fact, the theoretical relation between the distribution of solute at solid-liquid interface and current density was established, and the effect of current on the distribution coefficient of solute through effecting the rate of crystal growth, the solid-liquid interface energy and the radius of curvature at the dendritic tip was discussed. The results show that as the current density increases, the distribution coefficient of solute tends to rise in a whole, and when the former is larger than about 400 A/cm 2, the latter varies significantly.

Ultrafast laser-chemical modification hybrid fabrication of hydrostatic bearings with a superhydrophobicity solid-liquid interface

Oil film vortex severely reduces the stability of hydrostatic bearings. A solid-liquid interface with drag and slip properties can weaken the oil film vortex of the bearing. Here, a combined picosecond laser ablation and chemical modification method is proposed to prepare surfaces with microbulge array structure on 6061 aluminum alloy substrates. Because of the low surface energy of the perfluorododecyltriethoxysilane modification and the bulge geometry of the microbulge array structure, the surface shows excellent superhydrophobicity. The optimum contact angle in air for water is 164°, and that for oil is 139°. Two surfaces with “lotus-leaf effect” and “rose-petal effect” were obtained by controlling the processing parameters. The drag reduction properties of superhydrophobic surfaces were systematically investigated with slip lengths of 22.26 and 36.25 μm for deionized water and VG5 lubricant, respectively. In addition, the superhydrophobic surface exhibits excellent mechanical durability and thermal stability. The proposed method provides a new idea for vortex suppression in hydrostatic bearings and improves the stability of bearings in high-speed operation.

Atomic interface regulation of rare-marth metal single atom catalysts for energy conversion

Efficient photocatalysis and electrocatalysis in energy conversion have been important strategies to alleviate energy crises and environmental issues.In recent years,with the rapid development of emerging catalysts,significant progress has been made in photocatalysis for converting solar energy into chemical energy and electrocatalysis for converting electrical energy into chemical energy.However,their selectivity and efficiency of the products are poor.Rare earth(RE)can achieve atomic level fine regulation of catalysts and play an crucial role in optimizing catalyst performance by their unique electronic and orbital structures.However,there is a lack of systematic review on the atomic interface regulation mechanism of RE and their role in energy conversion processes.Single atom catalysts(SACs)provide clear active sites and 100%atomic utilization,which is conducive to exploring the regulatory mechanisms of RE.Therefore,this review mainly takes atomic level doped RE as an example to review and discuss the atomic interface regulation role of RE elements in energy conversion.Firstly,a brief introduction was given to the synthesis strategies that can effectively exert the atomic interface regulation effect of RE,with a focus on the atomic interface regulation mechanism of RE.Meanwhile,the regulatory mechanisms of RE atoms have been systematically summarized in various energy conversion applications.Finally,the challenges faced by RE in energy conversion,as well as future research directions and prospects,were pointed out.

Mode-I fracture and durability of FRP-concrete bonded interfaces

In this study, a work-of-fracture method using a three-point bend beam （3PBB） specimen, which is commonly used to determine the fracture energy of concrete, was adapted to evaluate the mode-I fracture and durability of fiber-reinforced polymer （FRP） composite-concrete bonded interfaces. Interface fracture properties were evaluated with established data reduction procedures. The proposed test method is primarily for use in evaluating the effects of freeze-thaw （F-T） and wet-dry （W-D） cycles that are the accelerated aging protocols on the mode-I fracture of carbon FRP-concrete bonded interfaces. The results of the mode-I fracture tests of F-T and W-D cycle-conditioned specimens show that both the critical load and fracture energy decrease as the number of cycles increases, and their degradation pattern has a nearly linear relationship with the number of cycles. However, compared with the effect of the F-T cycles, the critical load and fracture energy degrade at a slower rate with W-D cycles, which suggests that F-T cyclic conditioning causes more deterioration of carbon fiber-reinforced polymer （CFRP）-concrete bonded interface. After 50 and 100 conditioning cycles, scaling of concrete was observed in all the specimens subjected to F-T cycles, but not in those subjected to W-D cycles. The examination of interface fracture surfaces along the bonded interfaces with varying numbers of F-T and W-D conditioning cycles shows that （1） cohesive failure of CFRP composites is not observed in all fractured surfaces; （2） for the control specimens that have not been exposed to any conditioning cycles, the majority of interface failure is a result of cohesive fracture of concrete （peeling of concrete from the concrete substrate）, which means that the cracks mostly propagate within the concrete; and （3） as the number of F-T or W-D conditioning cycles increases, adhesive failure along the interface begins to emerge and gradually increases. It is thus concluded that the fracture properties （i.e., the critical load and fracture energy） of the bonded interface are controlled primarily by the concrete cohesive fracture before conditioning and by the adhesive interface fracture after many cycles of F-T or W-D conditioning. As demonstrated in this study, a test method using 3PBB specimens combined with a fictitious crack model and experimental conditioning protocols for durability can be used as an effective qualification method to test new hybrid material interface bonds and to evaluate durability-related effects on the interfaces.

Investigation on behavior of crack penetration/deflection at interfaces in intelligent coating system

Based on the three-phase model, the propagation behavior of a matrix crack in an intelligent coating system is investigated by an energy criterion. The effect of the elastic mismatch parameters and the thickness of the interface layer on the ratio of the energy release rate for infinitesimal deflected and penetrated crack is evaluated with the finite element method. The results show that the ratio of the energy release rates strongly depends on the elastic mismatch al between the substrate and the driving layer. It also strongly depends on the elastic mismatch a2 between the driving layer and the sensing layer for a thinner driving layer when a primary crack reaches an interface between the substrate and the driving layer. Moreover, with the increase in the thickness of the driving layer, the dependence on a2 gradually decreases. The experimental observation on aluminum alloys monitored with intelligent coating shows that the established model can better explain the behavior of matrix crack penetration and can be used in optimization design of intelligent coating.

Analysis of a permeable interface crack in elastic dielectric/piezoelectric bimaterials

A permeable interface crack between elastic dielectric material and piezoelectric material is studied based on the extended Stroh＇s formalism. Motivated by strong engineering demands to design new composite materials, the authors perform numerical analysis of interface crack tip singularities and the crack tip energy release rates for 35 types of dissimilar bimaterials, respectively, which are constructed by five kinds of elastic dielectric materials： Epoxy, Polymer, Al2O3, SiC, and Si3N4 and seven kinds of practical piezoelectric ceramics： PZT-4, BaTiO3, PZT-5H, PZT-6B, PZT-TA, P-7, and PZT-PIC 151, respectively. The elastic dielectric material with much smaller permittivity than commercial piezoelectric ceramics is treated as a special transversely isotropic piezoelectric material with extremely small piezoelectricity. The present investigation shows that the structure of the singular field near the permeable interface crack tip consists of three singularities： r^-1/2±iε and r^-1/2, which is quite different from that in the impermeable interface crack. It can be concluded that different far field loading cases have significant influence on the near-tip fracture behaviors of the permeable interface crack. Based on the present theoretical treatment and numerical analysis, the electric field induced crack growth is well explained, which provides a better understanding of the failure mechanism induced from interface crack growth in elastic dielectric/piezoelectric bimaterials.