In this paper,we examine the functions a(n)and b(n),which respectively represent the number of cubic partitions and cubic partition pairs.Our work leads to the derivation of asymptotic formulas for both a(n)and b(n).A...In this paper,we examine the functions a(n)and b(n),which respectively represent the number of cubic partitions and cubic partition pairs.Our work leads to the derivation of asymptotic formulas for both a(n)and b(n).Additionally,we establish the upper and lower bounds of these functions,factoring in the explicit error terms involved.Crucially,our findings reveal that a(n)and b(n)both satisfy several inequalities such as log-concavity,third-order Turan inequalities,and strict log-subadditivity.展开更多
This study numerically examines the heat and mass transfer characteristics of two ternary nanofluids via converging and diverg-ing channels.Furthermore,the study aims to assess two ternary nanofluids combinations to d...This study numerically examines the heat and mass transfer characteristics of two ternary nanofluids via converging and diverg-ing channels.Furthermore,the study aims to assess two ternary nanofluids combinations to determine which configuration can provide better heat and mass transfer and lower entropy production,while ensuring cost efficiency.This work bridges the gap be-tween academic research and industrial feasibility by incorporating cost analysis,entropy generation,and thermal efficiency.To compare the velocity,temperature,and concentration profiles,we examine two ternary nanofluids,i.e.,TiO_(2)+SiO_(2)+Al_(2)O_(3)/H_(2)O and TiO_(2)+SiO_(2)+Cu/H_(2)O,while considering the shape of nanoparticles.The velocity slip and Soret/Dufour effects are taken into consideration.Furthermore,regression analysis for Nusselt and Sherwood numbers of the model is carried out.The Runge-Kutta fourth-order method with shooting technique is employed to acquire the numerical solution of the governed system of ordinary differential equations.The flow pattern attributes of ternary nanofluids are meticulously examined and simulated with the fluc-tuation of flow-dominating parameters.Additionally,the influence of these parameters is demonstrated in the flow,temperature,and concentration fields.For variation in Eckert and Dufour numbers,TiO_(2)+SiO_(2)+Al_(2)O_(3)/H_(2)O has a higher temperature than TiO_(2)+SiO_(2)+Cu/H_(2)O.The results obtained indicate that the ternary nanofluid TiO_(2)+SiO_(2)+Al_(2)O_(3)/H_(2)O has a higher heat transfer rate,lesser entropy generation,greater mass transfer rate,and lower cost than that of TiO_(2)+SiO_(2)+Cu/H_(2)O ternary nanofluid.展开更多
The rock-salt cubic SnSe compound with multiple valleys and inherent low thermal conductivity is considered to be a promising thermoelectric compound.In this study,heterogeneous Pb atoms were strategically introduced ...The rock-salt cubic SnSe compound with multiple valleys and inherent low thermal conductivity is considered to be a promising thermoelectric compound.In this study,heterogeneous Pb atoms were strategically introduced into the lattice of cubic SnSe matrix,synergistically adjusting the thermoelectric transport properties of samples by optimizing hole carrier concentration(n)and suppressing thermal conductivity(κ_(tot)).When the doping content reached 0.08 mol,the peak power factor(PF)at 300 K increased to 20.00μW·cm^(-1)·K^(-2).The growing internal microstrain induced by the differences in atomic size strengthened the phonon scattering and effectively reduced the lattice thermal conductivity(κ_(L)).With further decoupling of the electrical and thermal transport properties,a peak thermoelectric figure of merit(ZT)of 0.82 and an average ZT of 0.42(300-750 K)were achieved in the samples doped with 0.10 mol Pb.These findings highlight the effectiveness of the selected dopants and demonstrate their synergy in improving the performance of thermoelectric materials.展开更多
This paper is concerned with the construction of two types of generalized Heisenberg supermagnet model with the constraint S^(3)=S,including the inhomogeneous Heisenberg supermagnet model in(1+1)dimensions and the(2+1...This paper is concerned with the construction of two types of generalized Heisenberg supermagnet model with the constraint S^(3)=S,including the inhomogeneous Heisenberg supermagnet model in(1+1)dimensions and the(2+1)-dimensional Heisenberg supermagnet model.Furthermore,by means of the gauge transformation,we investigate the gauge equivalent counterparts,which are the(1+1)-dimensional inhomogeneous nonlinear Schrodinger equation and the(2+1)-dimensional super nonlinear Schrodinger equation,respectively.展开更多
The China-type cubic press(CCP)is widely used in the high-pressure field because of its simple operation and low cost.However,the low ultimate pressure inside the cavity of CCP has limited its application.In order to ...The China-type cubic press(CCP)is widely used in the high-pressure field because of its simple operation and low cost.However,the low ultimate pressure inside the cavity of CCP has limited its application.In order to improve the ultimate pressure of the cavity,this paper simulates the pressure transfer efficiency and the Von Mises stress(VMS)of the tungsten carbide(WC)anvil.We find that the effect of the pretightening force of the WC anvil can be changed by changing the angle of the steel supporting ring.When the angle of the steel supporting ring is 1.2°,the pretightening force of the WC anvil is the most uniform,and the support effect of the WC anvil is the best.At the same time,this paper designs a double-beveled WC(D-WC)anvil.The D-WC anvil can not only improve the ultimate pressure of the cavity,but also ensure the stability of the cavity and the durability of the WC anvil.The design in this paper can also be used with the first-stage pressurization assembly to achieve better pressurization effect.展开更多
The nonlinear Schrodinger equation(NLSE) is a key tool for modeling wave propagation in nonlinear and dispersive media. This study focuses on the complex cubic NLSE with δ-potential,explored through the Brownian proc...The nonlinear Schrodinger equation(NLSE) is a key tool for modeling wave propagation in nonlinear and dispersive media. This study focuses on the complex cubic NLSE with δ-potential,explored through the Brownian process. The investigation begins with the derivation of stochastic solitary wave solutions using the modified exp(-Ψ(ξ)) expansion method. To illustrate the noise effects, 3D and 2D visualizations are displayed for different non-negative values of noise parameter under suitable parameter values. Additionally, qualitative analysis of both perturbed and unperturbed dynamical systems is conducted using bifurcation and chaos theory. In bifurcation analysis, we analyze the detailed parameter analysis near fixed points of the unperturbed system. An external periodic force is applied to perturb the system, leading to an investigation of its chaotic behavior. Chaos detection tools are employed to predict the behavior of the perturbed dynamical system, with results validated through visual representations.Multistability analysis is conducted under varying initial conditions to identify multiple stable states in the perturbed dynamical system, contributing to chaotic behavior. Also, sensitivity analysis of the Hamiltonian system is performed for different initial conditions. The novelty of this work lies in the significance of the obtained results, which have not been previously explored for the considered equation. These findings offer noteworthy insights into the behavior of the complex cubic NLSE with δ-potential and its applications in fields such as nonlinear optics, quantum mechanics and Bose–Einstein condensates.展开更多
The cubic pyrochlore Tl_(2)Ru_(2)O_(7) undergoes concurrently a metal–insulator transition (MIT) and a first-order structural transition at T_(MIT)≈120 K,below which the system was found to form one-dimensional spin...The cubic pyrochlore Tl_(2)Ru_(2)O_(7) undergoes concurrently a metal–insulator transition (MIT) and a first-order structural transition at T_(MIT)≈120 K,below which the system was found to form one-dimensional spin-one Haldane chains associated with an orbital ordering of Ru-4d electrons.With an aim to tune and access distinct ground states with strong entanglements of multiple degrees of freedom,i.e.,spin,orbital,charge,and lattice,we utilize a high-pressure approach to regulate the MIT of this system.Our detailed resistivityρ(T) measurements on the polycrystalline Tl_(2)Ru_(2)O_(7) samples under various hydrostatic pressures indeed reveal an unusual evolution of the electronic ground states.At first,the MIT is suppressed monotonically from 120 K at ambient to about 70 K at 1.5 GPa and then vanishes suddenly at about 1.8 GPa without achieving a metallic ground state.Meanwhile,the system evolves into a semiconducting ground state with magnitude ofρ(T) in the entire temperature range enhanced gradually by further increasing pressure.Prior to the abrupt disappearance of MIT,a new electronic order manifested as a kink-like anomaly inρ(T) emerges at T_(0)>T_(MIT) at 1.2 GPa and it continues to increase with pressure,producing a tricritical-point-like behavior in the T–P phase diagram of Tl_(2)Ru_(2)O_(7).The presence of two successive transitions at T_(0 )and T_(MIT )in the pressure range 1.2–1.5 GPa indicates an inhomogeneous electronic state nearby the tricritical point.At P≥3 GPa,another broad anomaly emerges inρ(T) at T_(1)>T_(0),and T_(1)continuously increases with pressure,dividing the semiconductingρ(T) into distinct thermally activated regions.These rich phenomena in the pressurized Tl_(2)Ru_(2)O_(7) should originate from the complex interplay of strongly entangled multiple quantum degrees of freedom in the system near the localized-to-itinerant crossover regime.展开更多
We observed superconductivity in a cubic La_(3)Al single crystal that exhibits metallic behavior in the normal state without an observable structural transition and enters the superconducting state below T_(c)~6.32 K....We observed superconductivity in a cubic La_(3)Al single crystal that exhibits metallic behavior in the normal state without an observable structural transition and enters the superconducting state below T_(c)~6.32 K.Detailed characterization and analysis indicate that cubic La_(3)Al is a bulk type-Ⅱ BCS superconductor.Moreover,theoretical calculations show that it can host interstitial anionic electrons located at the body center of the cubic unit cell,which confirms electron-phonon coupling as the superconducting mechanism.Therefore,cubic La_(3)Al can be considered as a novel electride superconductor.展开更多
All-solid-state lithium ion batteries(ASSLIBs)have attracted much attention due to their high safety and increased energy density,which have become a substitute to conventional liquid electrolyte batteries[1].The deve...All-solid-state lithium ion batteries(ASSLIBs)have attracted much attention due to their high safety and increased energy density,which have become a substitute to conventional liquid electrolyte batteries[1].The development of high-performance solid electrolyte is the key to the development of solid-state battery technology.Solid-state electrolyte(SSE)materials should have high ionic conductivity,poor electronic conductivity,wide electrochemical window,and low electrode and electrolyte interface resistance.展开更多
As an important sustainable energy source,Li-ion batteries have been widely used in mobile phones,electric vehicles,large-scale energy storage and aerospace.However,due to the inevitable safety risks of traditional li...As an important sustainable energy source,Li-ion batteries have been widely used in mobile phones,electric vehicles,large-scale energy storage and aerospace.However,due to the inevitable safety risks of traditional liquid Li-ion batteries,the use of all-solid-state batteries to replace organic liquid electrolytes has become one of the most effective ways to solve safety problem.Solid-state electrolyte(SSE)is the core part of allsolid-state Li-ion battery,and ideal SSE has the characteristics of high ionic conductivity,wide enough electrochemical stability window,suitable mechanical strength and excellent chemical stability,the first among which is particularly an essential prerequisite.While,so far only a few SSEs exhibit the Li ionic conductivities higher than 10^(-4) S/cm at room temperature.展开更多
Cubic silicon carbide(3C-SiC)has superior mobility and thermal conduction over that of widely applied hexagonal 4H-SiC.Moreover,much lower concentration of interfacial traps between insulating oxide gate and 3C-SiC he...Cubic silicon carbide(3C-SiC)has superior mobility and thermal conduction over that of widely applied hexagonal 4H-SiC.Moreover,much lower concentration of interfacial traps between insulating oxide gate and 3C-SiC helps fabricate reliable and long-life devices like metal-oxidesemiconductor field effect transistors.However,the growth of high-quality and wafer-scale 3C-SiC crystals has remained a big challenge up to now despite decades-long efforts by researchers because of its easy transformation into other polytypes during growth,limiting the development of 3C-SiC-based devices.Herein,we report that 3C-SiC can be made thermodynamically favored from nucleation to growth on a 4H-SiC substrate by top-seeded solution growth technique,beyond what is expected by classical nucleation theory.This enables the steady growth of high-quality and large-size 3C-SiC crystals(2-4-inch in diameter and 4.0-10.0 mm in thickness)sustainable.The as-grown 3C-SiC crystals are free of other polytypes and have high-crystalline quality.Our findings broaden the mechanism of hetero-seed crystal growth and provide a feasible route to mass production of 3C-SiC crystals,offering new opportunities to develop power electronic devices potentially with better performances than those based on 4H-SiC.展开更多
In order to comprehensively understand the mechanical behavior of biological entities and aerospace applications subjected to hypergravity environments,we delve into the impact of hypergravity on the equivalent compli...In order to comprehensively understand the mechanical behavior of biological entities and aerospace applications subjected to hypergravity environments,we delve into the impact of hypergravity on the equivalent compliance of cubic lattice structures.Capitalizing on the periodic spatial distribution,we employ a unit cell methodology to deduce the homogenized stress-strain relationship for the lattice structures,subsequently obtaining the associated equivalent compliance.The equivalent compliance can be conveniently reduced to instances without hypergravity influence.Furthermore,numerical simulations are executed to validate the derivations and to illustrate that hypergravity indeed affects the mechanical properties of lattice structures.We introduce a non-dimensional hypergravity factor,which quantifies the impact of hypergravity magnitude relative to the Young’s modulus of the base material.Our findings reveal that the hypergravity factor influences perpendicular compliance quadratically and parallel compliance linearly.Simultaneously,the perpendicular shear compliance remains unaffected,whereas the parallel shear compliance experiences an inverse effect.Additionally,the lattice structure transforms into a gradient material oriented in the hypergravity direction,consequently generating a scale effect.展开更多
Dehydrogenation is considered as one of the most important industrial applications for renewable energy.Cubic ceria-based catalysts are known to display promising dehydrogenation performances in this area.Large partic...Dehydrogenation is considered as one of the most important industrial applications for renewable energy.Cubic ceria-based catalysts are known to display promising dehydrogenation performances in this area.Large particle size(>20 nm)and less surface defects,however,hinder further application of ceria materials.Herein,an alternative strategy involving lactic acid(LA)assisted hydrothermal method was developed to synthesize active,selective and durable cubic ceria of<6 nm for dehydrogenation reactions.Detailed studies of growth mechanism revealed that,the carboxyl and hydroxyl groups in LA molecule synergistically manipulate the morphological evolution of ceria precursors.Carboxyl groups determine the cubic shape and particle size,while hydroxyl groups promote compositional transformation of ceria precursors into CeO_(2) phases.Moreover,enhanced oxygen vacancies(Vo)on the surface of CeO_(2) were obtained owing to continuous removal of O species under reductive atmosphere.Cubic CeO_(2) catalysts synthesized by the LA-assisted method,immobilized with bimetallic PtCo clusters,exhibit a record high activity(TOF:29,241 h^(-1))and Vo-dependent synergism for dehydrogenation of bio-derived polyols at 200℃.We also found that quenching Vo defects at air atmosphere causes activity loss of PtCo/CeO_(2) catalysts.To regenerate Vo defects,a simple strategy was developed by irradiating deactivated catalysts using hernia lamp.The outcome of this work will provide new insights into manufacturing durable catalyst materials for aqueous phase dehydrogenation applications.展开更多
Metastable nanostructured electrocatalyst with a completely different surface environment compared to conventional phase-based electrocatalyst often shows distinctive catalytic property.Although Ru-based electrocataly...Metastable nanostructured electrocatalyst with a completely different surface environment compared to conventional phase-based electrocatalyst often shows distinctive catalytic property.Although Ru-based electrocatalysts have been widely investigated toward hydrogen oxidation reaction(HOR)under alkaline electrolytes,these studies are mostly limited to conventional hexagonal-close-packed(hcp)phase,mainly arising from the lack of sufficient synthesis strategies.In this study,we report the precise synthesis of metastable binary RuW alloy with face-centered-cubic(fcc)phase.We find that the introduction of W can serve as fcc phase seeds and reduce the formation energy of metastable fcc-RuW alloy.Impressively,fcc-RuW exhibits remarkable alkaline HOR performance and stability with the activity of 0.67 mA cm_(Ru)^(-2)which is almost five and three times higher than that of hcp-Ru and commercial Pt/C,respectively,which is attributed to the optimized binding strength of adsorbed hydroxide intermediate derived from tailored electronic structure through W doping and phase engineering.Moreover,this strategy can also be applied to synthesize other metastable fcc-RuCr and fcc-RuMo alloys with enhanced HOR performances.展开更多
In traditional high-pressure–temperature assembly design, priority has been given to temperature insulation and retention at high pressures.This limits the efficiency of cooling of samples at the end of experiments, ...In traditional high-pressure–temperature assembly design, priority has been given to temperature insulation and retention at high pressures.This limits the efficiency of cooling of samples at the end of experiments, with a negative impact on many studies in high-pressure Earth andplanetary science. Inefficient cooling of experiments containing molten phases at high temperature leads to the formation of quench textures,which makes it impossible to quantify key compositional parameters of the original molten phase, such as their volatile contents. Here,we present a new low-cost experimental assembly for rapid cooling in a six-anvil cubic press. This assembly not only retains high heatingefficiency and thermal insulation, but also enables a very high cooling rate (∼600 ℃/s from 1900 ℃ to the glass transition temperature).Without using expensive materials or external modification of the press, the cooling rate in an assembly (∼600 ℃/s) with cube lengths of38.5 mm is about ten times faster than that in the traditional assembly (∼60 ℃/s). Experiments yielding inhomogeneous quenched melttextures when the traditional assembly is used are shown to yield homogeneous silicate glass without quench textures when the rapid coolingassembly is used.展开更多
This study aims to formulate a steady-state mathematical model for a three-dimensional permeable enclosure(cavity)to determine the oil extraction rate using three distinct nanoparticles,SiO_(2),Al_(2)O_(3),and Fe_(2)O...This study aims to formulate a steady-state mathematical model for a three-dimensional permeable enclosure(cavity)to determine the oil extraction rate using three distinct nanoparticles,SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3),in unconventional oil reservoirs.The simulation is conducted for different parameters of volume fractions,porosities,and mass flow rates to determine the optimal oil recovery.The impact of nanoparticles on relative permeability(kr)and water is also investigated.The simulation process utilizes the finite volume ANSYS Fluent.The study results showed that when the mass flow rate at the inlet is low,oil recovery goes up.In addition,they indicated that silicon nanoparticles are better at getting oil out of the ground(i.e.,oil reservoir)than Al_(2)O_(3)and Fe_(2)O_(3).Most oil can be extracted from SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)at a rate of 97.8%,96.5%,and 88%,respectively.展开更多
A special class of cubic polynomials possessing decay of geometry property is studied.This class of cubic bimodal maps has generalized Fibonacci combinatorics.For maps with bounded combinatorics,we show that they have...A special class of cubic polynomials possessing decay of geometry property is studied.This class of cubic bimodal maps has generalized Fibonacci combinatorics.For maps with bounded combinatorics,we show that they have an absolutely continuous invariant probability measure.展开更多
In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effec...In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effectively enhance voltage gain and reduce device stress.To address the issue of low output voltage in current renewable energy power generation systems,this study proposes a novel non-isolated cubic high-gain DC-DC converter based on the traditional quadratic DC-DC boost converter by incorporating a SC and a SL-SC unit.Firstly,the proposed converter’s details are elaborated,including its topology structure,operating mode,voltage gain,device stress,and power loss.Subsequently,a comparative analysis is conducted on the voltage gain and device stress between the proposed converter and other high-gain converters.Then,a closed-loop simulation system is constructed to obtain simulation waveforms of various devices and explore the dynamic performance.Finally,an experimental prototype is built,experimental waveforms are obtained,and the experimental dynamic performance and conversion efficiency are analyzed.The theoretical analysis’s correctness is verified through simulation and experimental results.The proposed converter has advantages such as high voltage gain,low device stress,high conversion efficiency,simple control,and wide input voltage range,achieving a good balance between voltage gain,device stress,and power loss.The proposed converter is well-suited for renewable energy systems and holds theoretical significance and practical value in renewable energy applications.It provides an effective solution to the issue of low output voltage in renewable energy power generation systems.展开更多
In this article, we investigated the influence of size and initial water content on the effective diffusion coefficient of sweet potatoes samples cut into cubic and cylindrical shapes. The sizes of the cubic samples a...In this article, we investigated the influence of size and initial water content on the effective diffusion coefficient of sweet potatoes samples cut into cubic and cylindrical shapes. The sizes of the cubic samples are 0.5, 1, 1.5, 1.75, 2, 2.5 and 3 cm edge with a respective initial water content of 2.7, 3.76, 3.48, 2.68, 3.28, 2.17 and 2.29 kg/kgms. For cylindrical samples, the radius is set at 0.5 cm and sample heights are 1, 1.5, 2, 2.5, 3, 3.5 and 4 cm with respective water contents of 2.2, 3.19, 2.85, 2.1, 2.17, 2.39 and 2.03 kg/kgms. The effective diffusion coefficients of cubic samples are of the order of 10−10 and 10−9 m2∙s−1 grew with sample edge. As for the cylindrical samples, the effective diffusion coefficients were of the order of 10−9 m2∙s−1 and there was no linear correlation between cylinder height and their effective diffusion coefficient. As for the examination of the initial water content on the effective diffusion coefficient, it turned out that the initial water content had no influence on the effective diffusion coefficient of the sweet potato samples.展开更多
The fracture theory of cubic quasicrystal was developed. The exact analytic solution of a Mode Ⅲ Griffith crack in the material was obtained by using the Fourier transform and dual integral equations theory, and so t...The fracture theory of cubic quasicrystal was developed. The exact analytic solution of a Mode Ⅲ Griffith crack in the material was obtained by using the Fourier transform and dual integral equations theory, and so the displacement and stress fields, the stress intensity factor and strain energy release rate were determined. The results show that the stress intensity factor is independent of material constants, and the strain energy release rate is dependent on all material constants. These provide important information for studying the deformation and fracture of the new solid material.展开更多
基金supported by the National Natural Science Foundation of China(12371327)the Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0107).
文摘In this paper,we examine the functions a(n)and b(n),which respectively represent the number of cubic partitions and cubic partition pairs.Our work leads to the derivation of asymptotic formulas for both a(n)and b(n).Additionally,we establish the upper and lower bounds of these functions,factoring in the explicit error terms involved.Crucially,our findings reveal that a(n)and b(n)both satisfy several inequalities such as log-concavity,third-order Turan inequalities,and strict log-subadditivity.
基金supported by DST-FIST(Government of India)(Grant No.SR/FIST/MS-1/2017/13)and Seed Money Project(Grant No.DoRDC/733).
文摘This study numerically examines the heat and mass transfer characteristics of two ternary nanofluids via converging and diverg-ing channels.Furthermore,the study aims to assess two ternary nanofluids combinations to determine which configuration can provide better heat and mass transfer and lower entropy production,while ensuring cost efficiency.This work bridges the gap be-tween academic research and industrial feasibility by incorporating cost analysis,entropy generation,and thermal efficiency.To compare the velocity,temperature,and concentration profiles,we examine two ternary nanofluids,i.e.,TiO_(2)+SiO_(2)+Al_(2)O_(3)/H_(2)O and TiO_(2)+SiO_(2)+Cu/H_(2)O,while considering the shape of nanoparticles.The velocity slip and Soret/Dufour effects are taken into consideration.Furthermore,regression analysis for Nusselt and Sherwood numbers of the model is carried out.The Runge-Kutta fourth-order method with shooting technique is employed to acquire the numerical solution of the governed system of ordinary differential equations.The flow pattern attributes of ternary nanofluids are meticulously examined and simulated with the fluc-tuation of flow-dominating parameters.Additionally,the influence of these parameters is demonstrated in the flow,temperature,and concentration fields.For variation in Eckert and Dufour numbers,TiO_(2)+SiO_(2)+Al_(2)O_(3)/H_(2)O has a higher temperature than TiO_(2)+SiO_(2)+Cu/H_(2)O.The results obtained indicate that the ternary nanofluid TiO_(2)+SiO_(2)+Al_(2)O_(3)/H_(2)O has a higher heat transfer rate,lesser entropy generation,greater mass transfer rate,and lower cost than that of TiO_(2)+SiO_(2)+Cu/H_(2)O ternary nanofluid.
基金supported by Taishan Scholar Program of Shandong Province(No.tsqn202306225)Shandong Postdoctoral Science Foundation(SDBX2023025)+2 种基金Leader of Scientific Research Studio Program of Jinan(No.2021GXRC082)University of Jinan Disciplinary Cross-Convergence Construction Projects 2023(Nos.XKJC-202301 and XKJC-202311)Jinan City-School Integration Development Strategy Project(Nos.JNSX2023015 and JNSX2023018).
文摘The rock-salt cubic SnSe compound with multiple valleys and inherent low thermal conductivity is considered to be a promising thermoelectric compound.In this study,heterogeneous Pb atoms were strategically introduced into the lattice of cubic SnSe matrix,synergistically adjusting the thermoelectric transport properties of samples by optimizing hole carrier concentration(n)and suppressing thermal conductivity(κ_(tot)).When the doping content reached 0.08 mol,the peak power factor(PF)at 300 K increased to 20.00μW·cm^(-1)·K^(-2).The growing internal microstrain induced by the differences in atomic size strengthened the phonon scattering and effectively reduced the lattice thermal conductivity(κ_(L)).With further decoupling of the electrical and thermal transport properties,a peak thermoelectric figure of merit(ZT)of 0.82 and an average ZT of 0.42(300-750 K)were achieved in the samples doped with 0.10 mol Pb.These findings highlight the effectiveness of the selected dopants and demonstrate their synergy in improving the performance of thermoelectric materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.12461048 and 12061051)Natural Science Foundation of Inner Mongolia Autonomous Region(Grant No.2023MS01003)+2 种基金the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(Grant No.NJYT23096)the financial support from the Program of China Scholarships Council(Grant No.202306810054)for one year's study at the University of Leedsthe support of Professor Ke Wu and Professor Weizhong Zhao at Capital Normal University,China。
文摘This paper is concerned with the construction of two types of generalized Heisenberg supermagnet model with the constraint S^(3)=S,including the inhomogeneous Heisenberg supermagnet model in(1+1)dimensions and the(2+1)-dimensional Heisenberg supermagnet model.Furthermore,by means of the gauge transformation,we investigate the gauge equivalent counterparts,which are the(1+1)-dimensional inhomogeneous nonlinear Schrodinger equation and the(2+1)-dimensional super nonlinear Schrodinger equation,respectively.
基金supported by the National Natural Science Foundation of China(Grant Nos.52272210 and 51872112)the Natural Science Foundation of Jilin Province of China(Grant Nos.20220101005JC and SKL202302007).
文摘The China-type cubic press(CCP)is widely used in the high-pressure field because of its simple operation and low cost.However,the low ultimate pressure inside the cavity of CCP has limited its application.In order to improve the ultimate pressure of the cavity,this paper simulates the pressure transfer efficiency and the Von Mises stress(VMS)of the tungsten carbide(WC)anvil.We find that the effect of the pretightening force of the WC anvil can be changed by changing the angle of the steel supporting ring.When the angle of the steel supporting ring is 1.2°,the pretightening force of the WC anvil is the most uniform,and the support effect of the WC anvil is the best.At the same time,this paper designs a double-beveled WC(D-WC)anvil.The D-WC anvil can not only improve the ultimate pressure of the cavity,but also ensure the stability of the cavity and the durability of the WC anvil.The design in this paper can also be used with the first-stage pressurization assembly to achieve better pressurization effect.
基金Supporting Project under Grant No.RSP2025R472,King Saud University,Riyadh,Saudi Arabia。
文摘The nonlinear Schrodinger equation(NLSE) is a key tool for modeling wave propagation in nonlinear and dispersive media. This study focuses on the complex cubic NLSE with δ-potential,explored through the Brownian process. The investigation begins with the derivation of stochastic solitary wave solutions using the modified exp(-Ψ(ξ)) expansion method. To illustrate the noise effects, 3D and 2D visualizations are displayed for different non-negative values of noise parameter under suitable parameter values. Additionally, qualitative analysis of both perturbed and unperturbed dynamical systems is conducted using bifurcation and chaos theory. In bifurcation analysis, we analyze the detailed parameter analysis near fixed points of the unperturbed system. An external periodic force is applied to perturb the system, leading to an investigation of its chaotic behavior. Chaos detection tools are employed to predict the behavior of the perturbed dynamical system, with results validated through visual representations.Multistability analysis is conducted under varying initial conditions to identify multiple stable states in the perturbed dynamical system, contributing to chaotic behavior. Also, sensitivity analysis of the Hamiltonian system is performed for different initial conditions. The novelty of this work lies in the significance of the obtained results, which have not been previously explored for the considered equation. These findings offer noteworthy insights into the behavior of the complex cubic NLSE with δ-potential and its applications in fields such as nonlinear optics, quantum mechanics and Bose–Einstein condensates.
基金supported by the National Key Research and Development Program of China (Grant Nos. 2023YFA1406100 and 2021YFA1400200)the National Natural Science Foundation of China (Grant Nos. 12025408 and 12174424)+2 种基金the Youth Innovation Promotion Association of Chinese Academy of Scineces (Grant No. 2023007)support from the National Natural Science Foundation of China (Grant No. 11904272)the Open Fund of Hubei Provincial Key Laboratory of Metallurgical Industry Process Systems Science (Grant No. Z202202)。
文摘The cubic pyrochlore Tl_(2)Ru_(2)O_(7) undergoes concurrently a metal–insulator transition (MIT) and a first-order structural transition at T_(MIT)≈120 K,below which the system was found to form one-dimensional spin-one Haldane chains associated with an orbital ordering of Ru-4d electrons.With an aim to tune and access distinct ground states with strong entanglements of multiple degrees of freedom,i.e.,spin,orbital,charge,and lattice,we utilize a high-pressure approach to regulate the MIT of this system.Our detailed resistivityρ(T) measurements on the polycrystalline Tl_(2)Ru_(2)O_(7) samples under various hydrostatic pressures indeed reveal an unusual evolution of the electronic ground states.At first,the MIT is suppressed monotonically from 120 K at ambient to about 70 K at 1.5 GPa and then vanishes suddenly at about 1.8 GPa without achieving a metallic ground state.Meanwhile,the system evolves into a semiconducting ground state with magnitude ofρ(T) in the entire temperature range enhanced gradually by further increasing pressure.Prior to the abrupt disappearance of MIT,a new electronic order manifested as a kink-like anomaly inρ(T) emerges at T_(0)>T_(MIT) at 1.2 GPa and it continues to increase with pressure,producing a tricritical-point-like behavior in the T–P phase diagram of Tl_(2)Ru_(2)O_(7).The presence of two successive transitions at T_(0 )and T_(MIT )in the pressure range 1.2–1.5 GPa indicates an inhomogeneous electronic state nearby the tricritical point.At P≥3 GPa,another broad anomaly emerges inρ(T) at T_(1)>T_(0),and T_(1)continuously increases with pressure,dividing the semiconductingρ(T) into distinct thermally activated regions.These rich phenomena in the pressurized Tl_(2)Ru_(2)O_(7) should originate from the complex interplay of strongly entangled multiple quantum degrees of freedom in the system near the localized-to-itinerant crossover regime.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFA1403800,2023YFA1406500,and 2022YFA1403103)the National Natural Science Foundation of China(Grant Nos.12274459,12174443,12074013,and 12404266)the Science Research Project of Hebei Education Department(Grant No.BJ2025060)。
文摘We observed superconductivity in a cubic La_(3)Al single crystal that exhibits metallic behavior in the normal state without an observable structural transition and enters the superconducting state below T_(c)~6.32 K.Detailed characterization and analysis indicate that cubic La_(3)Al is a bulk type-Ⅱ BCS superconductor.Moreover,theoretical calculations show that it can host interstitial anionic electrons located at the body center of the cubic unit cell,which confirms electron-phonon coupling as the superconducting mechanism.Therefore,cubic La_(3)Al can be considered as a novel electride superconductor.
文摘All-solid-state lithium ion batteries(ASSLIBs)have attracted much attention due to their high safety and increased energy density,which have become a substitute to conventional liquid electrolyte batteries[1].The development of high-performance solid electrolyte is the key to the development of solid-state battery technology.Solid-state electrolyte(SSE)materials should have high ionic conductivity,poor electronic conductivity,wide electrochemical window,and low electrode and electrolyte interface resistance.
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2020MB049)the Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai(No.AMGM2023A07)。
文摘As an important sustainable energy source,Li-ion batteries have been widely used in mobile phones,electric vehicles,large-scale energy storage and aerospace.However,due to the inevitable safety risks of traditional liquid Li-ion batteries,the use of all-solid-state batteries to replace organic liquid electrolytes has become one of the most effective ways to solve safety problem.Solid-state electrolyte(SSE)is the core part of allsolid-state Li-ion battery,and ideal SSE has the characteristics of high ionic conductivity,wide enough electrochemical stability window,suitable mechanical strength and excellent chemical stability,the first among which is particularly an essential prerequisite.While,so far only a few SSEs exhibit the Li ionic conductivities higher than 10^(-4) S/cm at room temperature.
基金supported by the Beijing Municipal Science and Technology Project(Grant No.Z211100004821004)the Special Project on Transfer and Conversion of Scientific and Technological Achievements of the Chinese Academy of Sciences(Grant No.KFJ-HGZX-042)
文摘Cubic silicon carbide(3C-SiC)has superior mobility and thermal conduction over that of widely applied hexagonal 4H-SiC.Moreover,much lower concentration of interfacial traps between insulating oxide gate and 3C-SiC helps fabricate reliable and long-life devices like metal-oxidesemiconductor field effect transistors.However,the growth of high-quality and wafer-scale 3C-SiC crystals has remained a big challenge up to now despite decades-long efforts by researchers because of its easy transformation into other polytypes during growth,limiting the development of 3C-SiC-based devices.Herein,we report that 3C-SiC can be made thermodynamically favored from nucleation to growth on a 4H-SiC substrate by top-seeded solution growth technique,beyond what is expected by classical nucleation theory.This enables the steady growth of high-quality and large-size 3C-SiC crystals(2-4-inch in diameter and 4.0-10.0 mm in thickness)sustainable.The as-grown 3C-SiC crystals are free of other polytypes and have high-crystalline quality.Our findings broaden the mechanism of hetero-seed crystal growth and provide a feasible route to mass production of 3C-SiC crystals,offering new opportunities to develop power electronic devices potentially with better performances than those based on 4H-SiC.
基金supported by the National Natural Science Foundation of China(Grant Nos.11925206,51988101,and 12272340)Zhejiang Provincial Natural Science Foundation of China(Grant No.LD21A020002).
文摘In order to comprehensively understand the mechanical behavior of biological entities and aerospace applications subjected to hypergravity environments,we delve into the impact of hypergravity on the equivalent compliance of cubic lattice structures.Capitalizing on the periodic spatial distribution,we employ a unit cell methodology to deduce the homogenized stress-strain relationship for the lattice structures,subsequently obtaining the associated equivalent compliance.The equivalent compliance can be conveniently reduced to instances without hypergravity influence.Furthermore,numerical simulations are executed to validate the derivations and to illustrate that hypergravity indeed affects the mechanical properties of lattice structures.We introduce a non-dimensional hypergravity factor,which quantifies the impact of hypergravity magnitude relative to the Young’s modulus of the base material.Our findings reveal that the hypergravity factor influences perpendicular compliance quadratically and parallel compliance linearly.Simultaneously,the perpendicular shear compliance remains unaffected,whereas the parallel shear compliance experiences an inverse effect.Additionally,the lattice structure transforms into a gradient material oriented in the hypergravity direction,consequently generating a scale effect.
基金financial supports National Natural Science Foundation of China(22078365,21706290)Natural Science Foundation of Shandong Province(ZR2017MB004)+2 种基金Innovative Research Funding from Qingdao City,Shandong Province(17-1-1-80-jch)“Fundamental Research Funds for the Central Universities”and“the Development Fund of State Key Laboratory of Heavy Oil Processing”(17CX02017A,20CX02204A)Postgraduate Innovation Project(YCX2021057)from China University of Petroleum.
文摘Dehydrogenation is considered as one of the most important industrial applications for renewable energy.Cubic ceria-based catalysts are known to display promising dehydrogenation performances in this area.Large particle size(>20 nm)and less surface defects,however,hinder further application of ceria materials.Herein,an alternative strategy involving lactic acid(LA)assisted hydrothermal method was developed to synthesize active,selective and durable cubic ceria of<6 nm for dehydrogenation reactions.Detailed studies of growth mechanism revealed that,the carboxyl and hydroxyl groups in LA molecule synergistically manipulate the morphological evolution of ceria precursors.Carboxyl groups determine the cubic shape and particle size,while hydroxyl groups promote compositional transformation of ceria precursors into CeO_(2) phases.Moreover,enhanced oxygen vacancies(Vo)on the surface of CeO_(2) were obtained owing to continuous removal of O species under reductive atmosphere.Cubic CeO_(2) catalysts synthesized by the LA-assisted method,immobilized with bimetallic PtCo clusters,exhibit a record high activity(TOF:29,241 h^(-1))and Vo-dependent synergism for dehydrogenation of bio-derived polyols at 200℃.We also found that quenching Vo defects at air atmosphere causes activity loss of PtCo/CeO_(2) catalysts.To regenerate Vo defects,a simple strategy was developed by irradiating deactivated catalysts using hernia lamp.The outcome of this work will provide new insights into manufacturing durable catalyst materials for aqueous phase dehydrogenation applications.
基金the support from the National Natural Science Foundation of China(22272121,21972107)the National Key Research and Development program of China(2021YFB4001200)。
文摘Metastable nanostructured electrocatalyst with a completely different surface environment compared to conventional phase-based electrocatalyst often shows distinctive catalytic property.Although Ru-based electrocatalysts have been widely investigated toward hydrogen oxidation reaction(HOR)under alkaline electrolytes,these studies are mostly limited to conventional hexagonal-close-packed(hcp)phase,mainly arising from the lack of sufficient synthesis strategies.In this study,we report the precise synthesis of metastable binary RuW alloy with face-centered-cubic(fcc)phase.We find that the introduction of W can serve as fcc phase seeds and reduce the formation energy of metastable fcc-RuW alloy.Impressively,fcc-RuW exhibits remarkable alkaline HOR performance and stability with the activity of 0.67 mA cm_(Ru)^(-2)which is almost five and three times higher than that of hcp-Ru and commercial Pt/C,respectively,which is attributed to the optimized binding strength of adsorbed hydroxide intermediate derived from tailored electronic structure through W doping and phase engineering.Moreover,this strategy can also be applied to synthesize other metastable fcc-RuCr and fcc-RuMo alloys with enhanced HOR performances.
基金supported by National Natural Science Foundation of China Grant No.42250105 to Y.L.The Center for High Pressure Science and Technology Advanced Research is supported by the National Science Foundation of China(Grant Nos.U1530402 and U1930401).
文摘In traditional high-pressure–temperature assembly design, priority has been given to temperature insulation and retention at high pressures.This limits the efficiency of cooling of samples at the end of experiments, with a negative impact on many studies in high-pressure Earth andplanetary science. Inefficient cooling of experiments containing molten phases at high temperature leads to the formation of quench textures,which makes it impossible to quantify key compositional parameters of the original molten phase, such as their volatile contents. Here,we present a new low-cost experimental assembly for rapid cooling in a six-anvil cubic press. This assembly not only retains high heatingefficiency and thermal insulation, but also enables a very high cooling rate (∼600 ℃/s from 1900 ℃ to the glass transition temperature).Without using expensive materials or external modification of the press, the cooling rate in an assembly (∼600 ℃/s) with cube lengths of38.5 mm is about ten times faster than that in the traditional assembly (∼60 ℃/s). Experiments yielding inhomogeneous quenched melttextures when the traditional assembly is used are shown to yield homogeneous silicate glass without quench textures when the rapid coolingassembly is used.
基金The APC of this article is covered by Research Grant YUTP 015LCO-526。
文摘This study aims to formulate a steady-state mathematical model for a three-dimensional permeable enclosure(cavity)to determine the oil extraction rate using three distinct nanoparticles,SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3),in unconventional oil reservoirs.The simulation is conducted for different parameters of volume fractions,porosities,and mass flow rates to determine the optimal oil recovery.The impact of nanoparticles on relative permeability(kr)and water is also investigated.The simulation process utilizes the finite volume ANSYS Fluent.The study results showed that when the mass flow rate at the inlet is low,oil recovery goes up.In addition,they indicated that silicon nanoparticles are better at getting oil out of the ground(i.e.,oil reservoir)than Al_(2)O_(3)and Fe_(2)O_(3).Most oil can be extracted from SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)at a rate of 97.8%,96.5%,and 88%,respectively.
文摘A special class of cubic polynomials possessing decay of geometry property is studied.This class of cubic bimodal maps has generalized Fibonacci combinatorics.For maps with bounded combinatorics,we show that they have an absolutely continuous invariant probability measure.
基金This work was supported by China Railway Corporation Science and Technology Research and Development Project(P2021J038).
文摘In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effectively enhance voltage gain and reduce device stress.To address the issue of low output voltage in current renewable energy power generation systems,this study proposes a novel non-isolated cubic high-gain DC-DC converter based on the traditional quadratic DC-DC boost converter by incorporating a SC and a SL-SC unit.Firstly,the proposed converter’s details are elaborated,including its topology structure,operating mode,voltage gain,device stress,and power loss.Subsequently,a comparative analysis is conducted on the voltage gain and device stress between the proposed converter and other high-gain converters.Then,a closed-loop simulation system is constructed to obtain simulation waveforms of various devices and explore the dynamic performance.Finally,an experimental prototype is built,experimental waveforms are obtained,and the experimental dynamic performance and conversion efficiency are analyzed.The theoretical analysis’s correctness is verified through simulation and experimental results.The proposed converter has advantages such as high voltage gain,low device stress,high conversion efficiency,simple control,and wide input voltage range,achieving a good balance between voltage gain,device stress,and power loss.The proposed converter is well-suited for renewable energy systems and holds theoretical significance and practical value in renewable energy applications.It provides an effective solution to the issue of low output voltage in renewable energy power generation systems.
文摘In this article, we investigated the influence of size and initial water content on the effective diffusion coefficient of sweet potatoes samples cut into cubic and cylindrical shapes. The sizes of the cubic samples are 0.5, 1, 1.5, 1.75, 2, 2.5 and 3 cm edge with a respective initial water content of 2.7, 3.76, 3.48, 2.68, 3.28, 2.17 and 2.29 kg/kgms. For cylindrical samples, the radius is set at 0.5 cm and sample heights are 1, 1.5, 2, 2.5, 3, 3.5 and 4 cm with respective water contents of 2.2, 3.19, 2.85, 2.1, 2.17, 2.39 and 2.03 kg/kgms. The effective diffusion coefficients of cubic samples are of the order of 10−10 and 10−9 m2∙s−1 grew with sample edge. As for the cylindrical samples, the effective diffusion coefficients were of the order of 10−9 m2∙s−1 and there was no linear correlation between cylinder height and their effective diffusion coefficient. As for the examination of the initial water content on the effective diffusion coefficient, it turned out that the initial water content had no influence on the effective diffusion coefficient of the sweet potato samples.
文摘The fracture theory of cubic quasicrystal was developed. The exact analytic solution of a Mode Ⅲ Griffith crack in the material was obtained by using the Fourier transform and dual integral equations theory, and so the displacement and stress fields, the stress intensity factor and strain energy release rate were determined. The results show that the stress intensity factor is independent of material constants, and the strain energy release rate is dependent on all material constants. These provide important information for studying the deformation and fracture of the new solid material.
