Let A be a 3×3 singular or diagonalizable matrix,all solutions to the Yang-Baxter-like matrix equation have been determined.However,finding all solutions for full rank,non-diagonalizable matrices remains challeng...Let A be a 3×3 singular or diagonalizable matrix,all solutions to the Yang-Baxter-like matrix equation have been determined.However,finding all solutions for full rank,non-diagonalizable matrices remains challenging.By utilizing classification techniques,we establish all solutions of the Yang-Baxter-like matrix equation in this paper when the coefficient matrix A is similar to non-diagonalizable matrix diag(λ,J_(2)(λ))withλ̸=0.More specifically,we divide the non-diagonal elements of the solution into 10 different cases.By discussing each situation,we establish all solutions of the Yang-Baxter-like matrix equation.The results of this work enrich the existing ones.展开更多
The use of Al-V alloys as intermediate additives is pivotal for producing high-performance Ti alloys.Traditionally,the synthesis of these alloys relies on high-purity V_(2)O_(5),with sodium metavanadate as an essentia...The use of Al-V alloys as intermediate additives is pivotal for producing high-performance Ti alloys.Traditionally,the synthesis of these alloys relies on high-purity V_(2)O_(5),with sodium metavanadate as an essential intermediate in V_(2)O_(5)production.This study explores an alternative approach utilizing sodium metavanadate directly,offering an aluminothermic process to alleviate the environmental impact and reduce the time required for V_(2)O_(5)preparation.Al-V alloys are synthesized using sodium metavanadate derived from a shale V-rich solution,and the impurity-migration behaviors are comprehensively analyzed,specifically focusing on Fe,Al,and Na.The result sreveal that Al interacts with CaO to form a slag phase that is different from the alloy,whereas Na undergoes a sequence of reductions (NaVO_(3)→Na_(2)V_(2)O_(5)→NaVO_(2)→Na)and volatilizes at 25-1200℃,thereby avoiding incorporation into the alloy.Fe,reduced by Al,enriches the alloy phase and induces a phase transition(Al-V→Al-Fe→Fe-V)in the presence of excess Fe.Sodium metavanadate(Fe≤0.05wt%)derived from the shale V-rich solution enables the production of a uniform AlV65 alloy with 66.56wt%V,33.14wt%Al,0.08wt%Fe,0.07wt%C,0.02wt%N,and 0.12wt%O.These results establish a streamlined,efficient framework for the future preparation of Al-V alloys from shale V-rich solutions.展开更多
The manufacturing industry is the core support for the development of the real economy.While promoting rapid economic growth,it also brings severe resource and environmental challenges.China's manufacturing indust...The manufacturing industry is the core support for the development of the real economy.While promoting rapid economic growth,it also brings severe resource and environmental challenges.China's manufacturing industry has ranked first in the world in terms of energy consumption,accounting for 56%of China's total energy consumption.Its electricity consumption exceeds 50%of the total social electricity consumption,and its carbon emissions reach 1.81 billion tons,accounting for 34% of the national total.Against this backdrop,enhancing the sustainability of high-end equipment manufacturing industries represented by aerospace has become a major strategic need for China's modernization,and it also provides strong support for solving global environmental problems.展开更多
In this study,high-performance D18:L8-BO bulk heterojunction organic solar cells(OSCs)were prepared by employing a hot-solution strategy to optimize the active layer morphology during the film solidification process.B...In this study,high-performance D18:L8-BO bulk heterojunction organic solar cells(OSCs)were prepared by employing a hot-solution strategy to optimize the active layer morphology during the film solidification process.By heating the chloroform(CF)solution to 70℃(slightly above the boiling point of CF,~61.2℃),an optimal balance between solvent evaporation and molecular self-assembly was achieved,resulting in enhanced crystallinity,favorable π-π stacking,and ideal nanoscale phase separation.These improvements significantly boost the power conversion efficiency from 17.74%(for the device processed at a room temperature of 30℃)to 19.56%.Moreover,the in-situ grazing-incidence wide-angle X-ray scattering technology was utilized to monitor the crystallization and morphology evolution of the active layer,offering real-time insights into molecule self-assembly and phase separation dynamics during active layer solidification.This work not only provides a simple and scalable approach for fabricating high-efficiency OSCs but also offers fundamental insights into the influence of solution temperature on active layer morphology evolution dynamics,paving the way for large-scale industrial production of organic solar cells.展开更多
Semitransparent organic photovoltaics(ST-OPVs)for building integration represent a pivotal direction in the development of photovoltaic industry.Solution-processed silver nanowires(AgNWs)are considered promising candi...Semitransparent organic photovoltaics(ST-OPVs)for building integration represent a pivotal direction in the development of photovoltaic industry.Solution-processed silver nanowires(AgNWs)are considered promising candidates for transparent electrodes in semitransparent devices due to their high transparency-conductivity-efficiency merit,large-scale processability,and low cost.In this work,we develop two solution-processed organic–inorganic hybrid electrodes,named AgNWs-PD and AgNWsPC,utilizing AgNWs as the conductive framework and aliphatic amine-functionalized perylene-diimide(PDINN)as the sandwiched material,while AgNWs-PC exhibits significantly improved electrical conductivity and enhanced contact area with the underlying electron transport layer.The optimized device achieves a power conversion efficiency of 9.45%with an open circuit voltage of 0.846 V,a high filling factor of 75.4%,and an average visible transmittance(AVT)of 44.0%,delivering an outstanding light utilization efficiency(LUE)of 4.16%,which is the highest reported value for all solution-processed ST-OPVs.In addition,by coupling a 30-nm tellurium dioxide atop AgNWs-PC,the bifaciality factor of derivative devices improves from 73.7%to 99.4%,while maintaining a high bifacial LUE over 3.7%.Our results emphasize the superiority and effectiveness of PDINN-sandwiched AgNWs electrodes for highperformance and all solution-processed ST-OPVs.展开更多
In this study,FeCr_(x)MnAlCu(x=0,0.5,1.0,1.5,2.0)high-entropy alloys were fabricated using vacuum arc melting,and the corrosion behavior of these alloys in 3.5wt%NaCl solution at room temperature was investigated by e...In this study,FeCr_(x)MnAlCu(x=0,0.5,1.0,1.5,2.0)high-entropy alloys were fabricated using vacuum arc melting,and the corrosion behavior of these alloys in 3.5wt%NaCl solution at room temperature was investigated by electrochemical dynamic potential polarization curves and immersion experiments.The microstructure results show that the high-entropy alloy with x=0 has a body-centered cubic phase structure,whereas the high-entropy alloys with x=0.5–2.0 have a mixed face-centered cubic+body-centered cubic dual-phase structure.The corrosion results show that the corrosion resistance of the high-entropy alloy is increased with the increase in Cr content.Among them,the high-entropy alloy with x=2.0 exhibits the optimal corrosion resistance:the highest self-corrosion potential(E_(corr)=−0.354 V vs.Ag/AgCl),the smallest self-corrosion current density(I_(corr)=1.991×10^(−6)A·cm^(−2)),and the smallest corrosion rate(0.0292 mm/a).The composite passivation film of oxides and hydroxides is formed on the surface of the corroded high-entropy alloys,and the Cr_(2)O_(3)content is increased with the increase in Cr content,which effectively improves the stability and protective properties of the passivation film.展开更多
In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar perce...In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar percentage of Na_(2)Ni_(2)Ti_(6)O_(16)(NNTO)within Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)(NMTO),with x values of 10,20,30,40,and 50.Both XPS(X-ray Photoelectron Spectroscopy)and EDX(Energy Dispersive X-ray Spectroscopy)analyses unequivocally validated the formation of the NNMTO-x solid solutions.It was observed that when x is below 40,the NNMTO-x solid solution retains the structural characteristics of the original NMTO.However,beyond this threshold,significant alterations in crystal morphology were noted,accompanied by a noticeable decline in photocatalytic activity.Notably,the absorption edge of NNMTO-x(x<40)exhibited a shift towards the visible-light spectrum,thereby substantially broadening the absorption range.The findings highlight that NNMTO-30 possesses the most pronounced photocatalytic activity for the reduction of CO_(2).Specifically,after a 6 h irradiation period,the production rates of CO and CH_(4)were recorded at 42.38 and 1.47μmol/g,respectively.This investigation provides pivotal insights that are instrumental in the advancement of highly efficient and stable photocatalysts tailored for CO_(2)reduction processes.展开更多
To investigate the effect of solution treatment and aging process parameters on the microstructure and mechanical properties of TB18 titanium alloy,process optimization research was conducted based on the mixed-level ...To investigate the effect of solution treatment and aging process parameters on the microstructure and mechanical properties of TB18 titanium alloy,process optimization research was conducted based on the mixed-level orthogonal experiment design of factor levels.Results show that through range analysis,the significance order of process parameters is determined as follows:solution cooling method>solution temperature>aging time>aging temperature>solution time.Considering the strength-ductility matching and engineering application requirements,the benchmark parameters are selected as solution time of 1 h,solution cooling method of air cooling(AC),aging temperature of 525℃,and aging time of 4 h.Furthermore,the effects of solution temperature in the range of 790–870℃ on the impact toughness and micro-fracture characteristics of the alloy were studied.The results reveal that the larger the area of shear lip and fibrous zone,and the smaller the area of radiation zone,the better the toughness of the alloy.With the increase in solution temperature,the length of secondary cracks on the fracture surface increases,the number of dimples increases,and the toughness is enhanced.Based on the collaborative optimization of strength and toughness,the optimal heat treatment process for TB18 alloy is determined as 870℃/1 h,AC+525℃/4 h,AC.展开更多
In this paper,we consider a Schr¨odinger-Poisson system with sublinear nonlinearity.The growth of nonlinearity depends on potential function and a bounded function.We first obtain the existence of nontrivial solu...In this paper,we consider a Schr¨odinger-Poisson system with sublinear nonlinearity.The growth of nonlinearity depends on potential function and a bounded function.We first obtain the existence of nontrivial solution sequence with negative energy for the system via a variant Clark’s theorem.Then we get the asymptotical property of the solution sequence by L∞norm.展开更多
This study investigates the dimensionless quasi-geostrophic potential vorticity(QG-PV)equation with external sources.Employing the Gardner-Morikawa transformation and weakly nonlinear perturbation expansion,we derive ...This study investigates the dimensionless quasi-geostrophic potential vorticity(QG-PV)equation with external sources.Employing the Gardner-Morikawa transformation and weakly nonlinear perturbation expansion,we derive the nonlinear Boussinesq equation with external sources.We demonstrate the existence of explicit zero-order and first-order Wronskian solutions for the model equation whenα_4=0.Furthermore,using a modified Jacobi elliptic function method,we obtain soliton-like solutions for bothα_4=0 andα_4≠0.Analysis of these solutions reveals that the generalizedβ-plane approximation and shear flow are significant factors in inducing nonlinear Rossby waves,and that external sources play a crucial role in influencing Rossby wave behavior.展开更多
Tourism’s link to the Sustainable Development Goals has been a continuing emphasis,adding momentum to longstandingefforts to ensure tourism’s sustainability.Tourism transport is one of the largest sources of anthrop...Tourism’s link to the Sustainable Development Goals has been a continuing emphasis,adding momentum to longstandingefforts to ensure tourism’s sustainability.Tourism transport is one of the largest sources of anthropogenic carbonemissions,driving global ecological change with profound consequences for ecosystem functioning and biodiversity.Large-scale infrastructure projects such as railway expansion are increasingly promoted for their potential to reducetourism-related carbon dioxide emissions,yet their spatial ecological impacts on regional carbon cycles and ecosystemservices remain poorly understood.This study introduces the concept of Tourism Transport Ecological Efficiency(TTEE)to assess the relationship between human infrastructure,carbon emissions,and ecological sustainability.Using panel datafrom China’s railway expansion between 2011 and 2018,the study provides spatially explicit evidence of how transportinfrastructure shapes tourism’s ecological footprint.Results show that non-Eastern regions experienced a greater increasein TTEE(8.7%)compared to Eastern regions(5.5%),highlighting regional disparities in tourism transport ecologicalsustainability.Railway density had a significant positive direct effect on TTEE,particularly pronounced in non-Easternregions.Additionally,a significant indirect effect of railway density in nearby regions was identified.These findings revealthe interconnected ecological impacts of transport systems and underscore the importance of regionally targeted railwayinvestment strategies.By bridging infrastructure development with ecological processes,this study advances understandingof how tourism transport can be aligned with global carbon reduction goals and ecosystem protection.展开更多
We propose an optimization method based on evolutionary computation for the design of broadband high-efficiency current-biased reverse load-modulation power amplifiers(CB-RLM PAs).First,given the reverse load-modulati...We propose an optimization method based on evolutionary computation for the design of broadband high-efficiency current-biased reverse load-modulation power amplifiers(CB-RLM PAs).First,given the reverse load-modulation characteristics of CB-RLM PAs,a comprehensive objective function is proposed that combines multi-state impedance trajectory constraints with in-band performance deviations.For the saturation and 6 dB power back-off(PBO)states,approximately optimal impedance regions on the Smith chart are derived using impedance constraint circles based on load-pull simulations.These regions are used together with in-band performance deviations(e.g.,saturated efficiency,6 dB PBO efficiency,and saturated output power)for matching network optimization and design.Second,a multi-objective evolutionary algorithm based on decomposition with adaptive weights,neighborhood,and global replacement is integrated with harmonic balance simulations to optimize design parameters and evaluate performance.Finally,to validate the proposed method,a broadband CB-RLM PA operating from 0.6 to 1.8 GHz is designed and fabricated.Measurement results show that the efficiencies at saturation,6 dB PBO,and 8 dB PBO all exceed 43.6%,with saturated output power being maintained at 40.9–41.5 dBm,which confirms the feasibility and effectiveness of the proposed broadband high-efficiency CB-RLM PA optimization and design approach.展开更多
ZnO thin-film transistors(TFTs)with channel layers fabricated by spin-coating are demonstrated.A nano ZnO colloidal aqueous solution with zinc nitrate dissolved in it was first deposited on the ATO/ITO/glass substrate...ZnO thin-film transistors(TFTs)with channel layers fabricated by spin-coating are demonstrated.A nano ZnO colloidal aqueous solution with zinc nitrate dissolved in it was first deposited on the ATO/ITO/glass substrate by spin-coating process.The thin-film transistor with well-controlled and densely packed ZnO crystalline layer was obtained by thermal annealing the system of colloidal solution film coated ATO/ITO/glass substrate.By optimizing the fabrication conditions,the fabricated thin-film transistors exhibited superior field-effect properties,which were stable,highly transparent,n-channel and enhancement-mode with a channel mobility as large as 3.02 cm^(2)·V^(-1).s^(-1).Our method of fabricating ZnO thin-film transistors was simple,high efficiency,and feasible for the batch production with low cost.展开更多
This paper is concerned with an initial boundary value problem for the planar magnetohydrodynamic compressible flow with temperature dependent heat conductivity in a half-line.In particular,the transverse magnetic fie...This paper is concerned with an initial boundary value problem for the planar magnetohydrodynamic compressible flow with temperature dependent heat conductivity in a half-line.In particular,the transverse magnetic field is assumed to satisfy the Neumann boundary condition,which was first investigated by Kazhikhov in 1987.We establish the global existence of the unique strong solutions to the MHD equations without any smallness conditions on the initial data.More precisely,our result can be regarded as a natural generalization of Kazhikov’s result for applying the constant heat-conductivity in bounded domains to the degenerate case in unbounded domains.展开更多
This study aims to explore how the Wei River Basin can enhance the efficiency of horizontal ecological compensation to promote high-quality and sustainable development in the Yellow River Basin.To achieve this,a four-...This study aims to explore how the Wei River Basin can enhance the efficiency of horizontal ecological compensation to promote high-quality and sustainable development in the Yellow River Basin.To achieve this,a four-stage DEA(Data Envelopment Analysis)method was employed to evaluate the efficiency of ecological compensation in six prefecture-level cities within the Wei River Basin from 2001 to 2022.In addition,the K-prototype clustering analysis method was integrated to assess the regional differences in ECE(ecological compensation efficiency).The findings indicate:(1)the ecological compensation efficiency in the upstream areas of the Wei River Basin is significantly higher than in the downstream regions;(2)the influence of factors such as the proportion of the tertiary industry,population density and residents’disposable income on the efficiency of ecological compensation is significant;(3)after excluding environmental factors,the overall ecological compensation efficiency showed a significant improvement.Based on these insights,it is recommended that the provinces of Shaanxi and Gansu further establish a robust compensation fund operation mechanism,build a cross-regional ecological compensation upstream-downstream coordination system,and strengthen inter-basin economic cooperation mechanisms to promote dual-driven development through technological advancement and scale benefits,thereby advancing ecological protection and sustainable development in the Wei River Basin.展开更多
Evaluating the effectivenes s of forest restoration projects is crucial for designing adaptive restoration strategies.However,existing studies have primarily focused on ecological outcomes while overlooking cost input...Evaluating the effectivenes s of forest restoration projects is crucial for designing adaptive restoration strategies.However,existing studies have primarily focused on ecological outcomes while overlooking cost inputs.This gap can lead to increased uncertainties in restoration planning.Here we investigated forest dynamics in China's Upper Yangtze River Basin(UYRB)using kernel Normalized Difference Vegetation Index(kNDVI),Leaf Area Index(LAI),Gross Primary Productivity(GPP),Ku-band Vegetation Optical Depth(Ku-VOD)time series and climate data from1982 to 2020.Subsequently,we employed a residual trend analysis integrating temporal effects to determine the relative contributions of climate change and human activities to forest dynamics before and after the implementation of forest restoration engineering in 1998.Additionally,we developed an Afforestation Efficiency Index(AEI)to quantitatively assess the cost efficiency of afforestation projects.Results indicated that forest in the UYRB showed sustained increases during 1982-2020,with most areas experiencing greater growth after 1998 than before.Temporal effects of climatic factors influenced over 42.7%of the forest,and incorporating time-lag and cumulative effects enhanced climate-based explanations of forest variations by 1.61-24.73%.Human activities emerged as the dominant driver of forest dynamics post 1998,whereas climate variables predominated before this period.The cost-effectiveness of forest restoration projects in the UYRB typically ranges from moderate to high,with higher success predominantly observed in the northeastern and eastern counties,while the central,western,and northwestern counties mainly showed relatively low efficiency.These findings stress the need for assessing forest restoration outcomes from both ecological and cost perspectives,and can offer valuable insights for optimizing the layout of forest restoration initiatives in the UYRB.展开更多
The goal of the present work is to demonstrate the potential of Artificial Neural Network(ANN)-driven Genetic Algorithm(GA)methods for energy efficiency and economic performance optimization of energy efficiency measu...The goal of the present work is to demonstrate the potential of Artificial Neural Network(ANN)-driven Genetic Algorithm(GA)methods for energy efficiency and economic performance optimization of energy efficiency measures in a multi-family house building in Greece.The energy efficiency measures include different heating/cooling systems(such as low-temperature and high-temperature heat pumps,natural gas boilers,split units),building envelope components for floor,walls,roof and windows of variable heat transfer coefficients,the installation of solar thermal collectors and PVs.The calculations of the building loads and investment and operating and maintenance costs of the measures are based on the methodology defined in Directive 2010/31/EU,while economic assumptions are based on EN 15459-1 standard.Typically,multi-objective optimization of energy efficiency measures often requires the simulation of very large numbers of cases involving numerous possible combinations,resulting in intense computational load.The results of the study indicate that ANN-driven GA methods can be used as an alternative,valuable tool for reliably predicting the optimal measures which minimize primary energy consumption and life cycle cost of the building with greatly reduced computational requirements.Through GA methods,the computational time needed for obtaining the optimal solutions is reduced by 96.4%-96.8%.展开更多
In this article,we show the existence,uniqueness and stability of bounded solutions to the following quasilinear problems with mean curvature operator(φ'(x′(t)))′=f(t,x),t≥t_(0),lim_(t→∞)x(t)=ψ_(0),lim_(t→...In this article,we show the existence,uniqueness and stability of bounded solutions to the following quasilinear problems with mean curvature operator(φ'(x′(t)))′=f(t,x),t≥t_(0),lim_(t→∞)x(t)=ψ_(0),lim_(t→∞)x′(t)e^(t)=0,where t_(0) and ψ_(0) are real constants,φ(s)=s/√1−s^(2),s∈R with s∈(−1,1),f:[t_(0),∞)×R→R satisfies the Lipschitz or Osgood-type conditions.展开更多
Composite resin restorations are routinely exposed to acidic and chromogenic beverages that may alter their surface integrity over time.This in-vitro study evaluated the surface roughness behavior of two universal sin...Composite resin restorations are routinely exposed to acidic and chromogenic beverages that may alter their surface integrity over time.This in-vitro study evaluated the surface roughness behavior of two universal single-shade(Unishade)composites and two conventionalmulti-shade composites following immersion in commonly consumed staining solutions and assessed whether repolishing could restore smoothness after degradation.A total of 120 standardized disc specimens were fabricated and allocated to fourmaterial groups,with each group subdivided into distilled water,cola,and coffee immersion subgroups.Surface roughness was recorded at baseline,after one week,after one month,and following a final repolishing step using a standardized multi-step system.The findings demonstrated that Unishade composites exhibited more stable surface characteristics across all immersion periods,with changes consistently remaining below the threshold associated with biofilm accumulation.Conventional composites showed greater variability,particularly in cola,where roughness values increased significantly compared with distilled water and coffee.Repolishing substantially reduced immersion-induced roughness in all materials,although its effectiveness varied depending on composite formulation and beverage acidity.Cola produced the greatest surface alterations across all groups,highlighting the erosive potential of low-pH beverages.These results indicate that Unishade composites possess superior resistance to surface degradation,likely due to their nano-structured filler configuration and less hydrophilic resin matrices,while conventional materials appear more susceptible to acidic challenge.Within the limitations of this study,selecting surface-stable material types and applying appropriate finishing and repolishing protocols may enhance the long-term performance and esthetics of composite restorations.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.62173161).
文摘Let A be a 3×3 singular or diagonalizable matrix,all solutions to the Yang-Baxter-like matrix equation have been determined.However,finding all solutions for full rank,non-diagonalizable matrices remains challenging.By utilizing classification techniques,we establish all solutions of the Yang-Baxter-like matrix equation in this paper when the coefficient matrix A is similar to non-diagonalizable matrix diag(λ,J_(2)(λ))withλ̸=0.More specifically,we divide the non-diagonal elements of the solution into 10 different cases.By discussing each situation,we establish all solutions of the Yang-Baxter-like matrix equation.The results of this work enrich the existing ones.
基金funded by the National Key R&D Pro-gram of China (No.2023YFC3903903)the Science and Technology Innovation Talent Program of Hubei Province,China (No.2022EJD002).
文摘The use of Al-V alloys as intermediate additives is pivotal for producing high-performance Ti alloys.Traditionally,the synthesis of these alloys relies on high-purity V_(2)O_(5),with sodium metavanadate as an essential intermediate in V_(2)O_(5)production.This study explores an alternative approach utilizing sodium metavanadate directly,offering an aluminothermic process to alleviate the environmental impact and reduce the time required for V_(2)O_(5)preparation.Al-V alloys are synthesized using sodium metavanadate derived from a shale V-rich solution,and the impurity-migration behaviors are comprehensively analyzed,specifically focusing on Fe,Al,and Na.The result sreveal that Al interacts with CaO to form a slag phase that is different from the alloy,whereas Na undergoes a sequence of reductions (NaVO_(3)→Na_(2)V_(2)O_(5)→NaVO_(2)→Na)and volatilizes at 25-1200℃,thereby avoiding incorporation into the alloy.Fe,reduced by Al,enriches the alloy phase and induces a phase transition(Al-V→Al-Fe→Fe-V)in the presence of excess Fe.Sodium metavanadate(Fe≤0.05wt%)derived from the shale V-rich solution enables the production of a uniform AlV65 alloy with 66.56wt%V,33.14wt%Al,0.08wt%Fe,0.07wt%C,0.02wt%N,and 0.12wt%O.These results establish a streamlined,efficient framework for the future preparation of Al-V alloys from shale V-rich solutions.
基金the support of the National Natural Science Foundation of China(Nos.52205476 and 52175415)the Natural Science Foundation of Jiangsu Province(No.BK20242040)+1 种基金the Fundamental Research Funds for the Central Universities(No.NG2024008)the Fund of Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology(No.1005ZAA20003-14)。
文摘The manufacturing industry is the core support for the development of the real economy.While promoting rapid economic growth,it also brings severe resource and environmental challenges.China's manufacturing industry has ranked first in the world in terms of energy consumption,accounting for 56%of China's total energy consumption.Its electricity consumption exceeds 50%of the total social electricity consumption,and its carbon emissions reach 1.81 billion tons,accounting for 34% of the national total.Against this backdrop,enhancing the sustainability of high-end equipment manufacturing industries represented by aerospace has become a major strategic need for China's modernization,and it also provides strong support for solving global environmental problems.
基金financially supported by the National Natural Science Foundation of China(61705003)。
文摘In this study,high-performance D18:L8-BO bulk heterojunction organic solar cells(OSCs)were prepared by employing a hot-solution strategy to optimize the active layer morphology during the film solidification process.By heating the chloroform(CF)solution to 70℃(slightly above the boiling point of CF,~61.2℃),an optimal balance between solvent evaporation and molecular self-assembly was achieved,resulting in enhanced crystallinity,favorable π-π stacking,and ideal nanoscale phase separation.These improvements significantly boost the power conversion efficiency from 17.74%(for the device processed at a room temperature of 30℃)to 19.56%.Moreover,the in-situ grazing-incidence wide-angle X-ray scattering technology was utilized to monitor the crystallization and morphology evolution of the active layer,offering real-time insights into molecule self-assembly and phase separation dynamics during active layer solidification.This work not only provides a simple and scalable approach for fabricating high-efficiency OSCs but also offers fundamental insights into the influence of solution temperature on active layer morphology evolution dynamics,paving the way for large-scale industrial production of organic solar cells.
基金financially supported by the National Natural Science Foundation of China(21905137)the Research Grants Council of Hong Kong(15307922,C5037-18G,C4005-22Y)+1 种基金RGC Senior Research Fellowship Scheme(SRFS2223-5S01)the Hong Kong Polytechnic University:Sir Sze-yuen Chung Endowed Professorship Fund(8-8480)。
文摘Semitransparent organic photovoltaics(ST-OPVs)for building integration represent a pivotal direction in the development of photovoltaic industry.Solution-processed silver nanowires(AgNWs)are considered promising candidates for transparent electrodes in semitransparent devices due to their high transparency-conductivity-efficiency merit,large-scale processability,and low cost.In this work,we develop two solution-processed organic–inorganic hybrid electrodes,named AgNWs-PD and AgNWsPC,utilizing AgNWs as the conductive framework and aliphatic amine-functionalized perylene-diimide(PDINN)as the sandwiched material,while AgNWs-PC exhibits significantly improved electrical conductivity and enhanced contact area with the underlying electron transport layer.The optimized device achieves a power conversion efficiency of 9.45%with an open circuit voltage of 0.846 V,a high filling factor of 75.4%,and an average visible transmittance(AVT)of 44.0%,delivering an outstanding light utilization efficiency(LUE)of 4.16%,which is the highest reported value for all solution-processed ST-OPVs.In addition,by coupling a 30-nm tellurium dioxide atop AgNWs-PC,the bifaciality factor of derivative devices improves from 73.7%to 99.4%,while maintaining a high bifacial LUE over 3.7%.Our results emphasize the superiority and effectiveness of PDINN-sandwiched AgNWs electrodes for highperformance and all solution-processed ST-OPVs.
基金Gansu Provincial Science and Technology Major Special Program(24ZDWA008)Fourth Batch of Top Leading Talents Fund Projects in Gansu Province(ZZ2023G50100013)。
文摘In this study,FeCr_(x)MnAlCu(x=0,0.5,1.0,1.5,2.0)high-entropy alloys were fabricated using vacuum arc melting,and the corrosion behavior of these alloys in 3.5wt%NaCl solution at room temperature was investigated by electrochemical dynamic potential polarization curves and immersion experiments.The microstructure results show that the high-entropy alloy with x=0 has a body-centered cubic phase structure,whereas the high-entropy alloys with x=0.5–2.0 have a mixed face-centered cubic+body-centered cubic dual-phase structure.The corrosion results show that the corrosion resistance of the high-entropy alloy is increased with the increase in Cr content.Among them,the high-entropy alloy with x=2.0 exhibits the optimal corrosion resistance:the highest self-corrosion potential(E_(corr)=−0.354 V vs.Ag/AgCl),the smallest self-corrosion current density(I_(corr)=1.991×10^(−6)A·cm^(−2)),and the smallest corrosion rate(0.0292 mm/a).The composite passivation film of oxides and hydroxides is formed on the surface of the corroded high-entropy alloys,and the Cr_(2)O_(3)content is increased with the increase in Cr content,which effectively improves the stability and protective properties of the passivation film.
基金Supported by the Doctoral Research Start-up Project of Yuncheng University(YQ-2023067)Project of Shanxi Natural Science Foundation(202303021211189)+1 种基金Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Provinces(20220036)Shanxi ProvinceIntelligent Optoelectronic Sensing Application Technology Innovation Center and Shanxi Province Optoelectronic Information Science and TechnologyLaboratory,Yuncheng University.
文摘In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar percentage of Na_(2)Ni_(2)Ti_(6)O_(16)(NNTO)within Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)(NMTO),with x values of 10,20,30,40,and 50.Both XPS(X-ray Photoelectron Spectroscopy)and EDX(Energy Dispersive X-ray Spectroscopy)analyses unequivocally validated the formation of the NNMTO-x solid solutions.It was observed that when x is below 40,the NNMTO-x solid solution retains the structural characteristics of the original NMTO.However,beyond this threshold,significant alterations in crystal morphology were noted,accompanied by a noticeable decline in photocatalytic activity.Notably,the absorption edge of NNMTO-x(x<40)exhibited a shift towards the visible-light spectrum,thereby substantially broadening the absorption range.The findings highlight that NNMTO-30 possesses the most pronounced photocatalytic activity for the reduction of CO_(2).Specifically,after a 6 h irradiation period,the production rates of CO and CH_(4)were recorded at 42.38 and 1.47μmol/g,respectively.This investigation provides pivotal insights that are instrumental in the advancement of highly efficient and stable photocatalysts tailored for CO_(2)reduction processes.
基金Key Program of National Natural Science Foundation of China(52431001)。
文摘To investigate the effect of solution treatment and aging process parameters on the microstructure and mechanical properties of TB18 titanium alloy,process optimization research was conducted based on the mixed-level orthogonal experiment design of factor levels.Results show that through range analysis,the significance order of process parameters is determined as follows:solution cooling method>solution temperature>aging time>aging temperature>solution time.Considering the strength-ductility matching and engineering application requirements,the benchmark parameters are selected as solution time of 1 h,solution cooling method of air cooling(AC),aging temperature of 525℃,and aging time of 4 h.Furthermore,the effects of solution temperature in the range of 790–870℃ on the impact toughness and micro-fracture characteristics of the alloy were studied.The results reveal that the larger the area of shear lip and fibrous zone,and the smaller the area of radiation zone,the better the toughness of the alloy.With the increase in solution temperature,the length of secondary cracks on the fracture surface increases,the number of dimples increases,and the toughness is enhanced.Based on the collaborative optimization of strength and toughness,the optimal heat treatment process for TB18 alloy is determined as 870℃/1 h,AC+525℃/4 h,AC.
基金Supported by the National Natural Science Foundation of China(12226412)Natural Science Foundation of Jiangsu Province(BK20221339)。
文摘In this paper,we consider a Schr¨odinger-Poisson system with sublinear nonlinearity.The growth of nonlinearity depends on potential function and a bounded function.We first obtain the existence of nontrivial solution sequence with negative energy for the system via a variant Clark’s theorem.Then we get the asymptotical property of the solution sequence by L∞norm.
基金supported by the National Natural Science Foundation of China(Grant No.12362027)the Scientific Research Ability of Youth Teachers of Inner Mongolia Agricultural University(Grant No.BR230110)+3 种基金Inner Mongolia National Science Fund for Excellent Young Scholars(Grant No.2025YQ033)Foundation for Basic Science Research Initiation at Inner Mongolia Agricultural University(Grant No.JC2021001)The Natural Science Foundation of Inner Mongolia Autonomous Region(2025MS01020)Supported by the Basic and Applied Basic Research Science and Technology Program Projects of Hohhot(2025-rule-basic-60)。
文摘This study investigates the dimensionless quasi-geostrophic potential vorticity(QG-PV)equation with external sources.Employing the Gardner-Morikawa transformation and weakly nonlinear perturbation expansion,we derive the nonlinear Boussinesq equation with external sources.We demonstrate the existence of explicit zero-order and first-order Wronskian solutions for the model equation whenα_4=0.Furthermore,using a modified Jacobi elliptic function method,we obtain soliton-like solutions for bothα_4=0 andα_4≠0.Analysis of these solutions reveals that the generalizedβ-plane approximation and shear flow are significant factors in inducing nonlinear Rossby waves,and that external sources play a crucial role in influencing Rossby wave behavior.
文摘Tourism’s link to the Sustainable Development Goals has been a continuing emphasis,adding momentum to longstandingefforts to ensure tourism’s sustainability.Tourism transport is one of the largest sources of anthropogenic carbonemissions,driving global ecological change with profound consequences for ecosystem functioning and biodiversity.Large-scale infrastructure projects such as railway expansion are increasingly promoted for their potential to reducetourism-related carbon dioxide emissions,yet their spatial ecological impacts on regional carbon cycles and ecosystemservices remain poorly understood.This study introduces the concept of Tourism Transport Ecological Efficiency(TTEE)to assess the relationship between human infrastructure,carbon emissions,and ecological sustainability.Using panel datafrom China’s railway expansion between 2011 and 2018,the study provides spatially explicit evidence of how transportinfrastructure shapes tourism’s ecological footprint.Results show that non-Eastern regions experienced a greater increasein TTEE(8.7%)compared to Eastern regions(5.5%),highlighting regional disparities in tourism transport ecologicalsustainability.Railway density had a significant positive direct effect on TTEE,particularly pronounced in non-Easternregions.Additionally,a significant indirect effect of railway density in nearby regions was identified.These findings revealthe interconnected ecological impacts of transport systems and underscore the importance of regionally targeted railwayinvestment strategies.By bridging infrastructure development with ecological processes,this study advances understandingof how tourism transport can be aligned with global carbon reduction goals and ecosystem protection.
基金supported by the National Natural Science Foundation of China(Nos.62171204,62171129,62001192).
文摘We propose an optimization method based on evolutionary computation for the design of broadband high-efficiency current-biased reverse load-modulation power amplifiers(CB-RLM PAs).First,given the reverse load-modulation characteristics of CB-RLM PAs,a comprehensive objective function is proposed that combines multi-state impedance trajectory constraints with in-band performance deviations.For the saturation and 6 dB power back-off(PBO)states,approximately optimal impedance regions on the Smith chart are derived using impedance constraint circles based on load-pull simulations.These regions are used together with in-band performance deviations(e.g.,saturated efficiency,6 dB PBO efficiency,and saturated output power)for matching network optimization and design.Second,a multi-objective evolutionary algorithm based on decomposition with adaptive weights,neighborhood,and global replacement is integrated with harmonic balance simulations to optimize design parameters and evaluate performance.Finally,to validate the proposed method,a broadband CB-RLM PA operating from 0.6 to 1.8 GHz is designed and fabricated.Measurement results show that the efficiencies at saturation,6 dB PBO,and 8 dB PBO all exceed 43.6%,with saturated output power being maintained at 40.9–41.5 dBm,which confirms the feasibility and effectiveness of the proposed broadband high-efficiency CB-RLM PA optimization and design approach.
文摘ZnO thin-film transistors(TFTs)with channel layers fabricated by spin-coating are demonstrated.A nano ZnO colloidal aqueous solution with zinc nitrate dissolved in it was first deposited on the ATO/ITO/glass substrate by spin-coating process.The thin-film transistor with well-controlled and densely packed ZnO crystalline layer was obtained by thermal annealing the system of colloidal solution film coated ATO/ITO/glass substrate.By optimizing the fabrication conditions,the fabricated thin-film transistors exhibited superior field-effect properties,which were stable,highly transparent,n-channel and enhancement-mode with a channel mobility as large as 3.02 cm^(2)·V^(-1).s^(-1).Our method of fabricating ZnO thin-film transistors was simple,high efficiency,and feasible for the batch production with low cost.
基金supported by the National Natural Science Foundation of China(12401279,12371219)the Academic and Technical Leaders Training Plan of Jiangxi Province(20212BCJ23027).
文摘This paper is concerned with an initial boundary value problem for the planar magnetohydrodynamic compressible flow with temperature dependent heat conductivity in a half-line.In particular,the transverse magnetic field is assumed to satisfy the Neumann boundary condition,which was first investigated by Kazhikhov in 1987.We establish the global existence of the unique strong solutions to the MHD equations without any smallness conditions on the initial data.More precisely,our result can be regarded as a natural generalization of Kazhikov’s result for applying the constant heat-conductivity in bounded domains to the degenerate case in unbounded domains.
基金funded by the Gansu Soft Science Planning Project(Grant No.25JRZA170).
文摘This study aims to explore how the Wei River Basin can enhance the efficiency of horizontal ecological compensation to promote high-quality and sustainable development in the Yellow River Basin.To achieve this,a four-stage DEA(Data Envelopment Analysis)method was employed to evaluate the efficiency of ecological compensation in six prefecture-level cities within the Wei River Basin from 2001 to 2022.In addition,the K-prototype clustering analysis method was integrated to assess the regional differences in ECE(ecological compensation efficiency).The findings indicate:(1)the ecological compensation efficiency in the upstream areas of the Wei River Basin is significantly higher than in the downstream regions;(2)the influence of factors such as the proportion of the tertiary industry,population density and residents’disposable income on the efficiency of ecological compensation is significant;(3)after excluding environmental factors,the overall ecological compensation efficiency showed a significant improvement.Based on these insights,it is recommended that the provinces of Shaanxi and Gansu further establish a robust compensation fund operation mechanism,build a cross-regional ecological compensation upstream-downstream coordination system,and strengthen inter-basin economic cooperation mechanisms to promote dual-driven development through technological advancement and scale benefits,thereby advancing ecological protection and sustainable development in the Wei River Basin.
基金supported by the National Natural Science Foundation of China(42071238)the Jiuzhaigou Post-Disaster Restoration and Reconstruction Program(5132202020000046)+1 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)the Ministry of Science and Technology of the People's Republic of China(2019QZKK0402)。
文摘Evaluating the effectivenes s of forest restoration projects is crucial for designing adaptive restoration strategies.However,existing studies have primarily focused on ecological outcomes while overlooking cost inputs.This gap can lead to increased uncertainties in restoration planning.Here we investigated forest dynamics in China's Upper Yangtze River Basin(UYRB)using kernel Normalized Difference Vegetation Index(kNDVI),Leaf Area Index(LAI),Gross Primary Productivity(GPP),Ku-band Vegetation Optical Depth(Ku-VOD)time series and climate data from1982 to 2020.Subsequently,we employed a residual trend analysis integrating temporal effects to determine the relative contributions of climate change and human activities to forest dynamics before and after the implementation of forest restoration engineering in 1998.Additionally,we developed an Afforestation Efficiency Index(AEI)to quantitatively assess the cost efficiency of afforestation projects.Results indicated that forest in the UYRB showed sustained increases during 1982-2020,with most areas experiencing greater growth after 1998 than before.Temporal effects of climatic factors influenced over 42.7%of the forest,and incorporating time-lag and cumulative effects enhanced climate-based explanations of forest variations by 1.61-24.73%.Human activities emerged as the dominant driver of forest dynamics post 1998,whereas climate variables predominated before this period.The cost-effectiveness of forest restoration projects in the UYRB typically ranges from moderate to high,with higher success predominantly observed in the northeastern and eastern counties,while the central,western,and northwestern counties mainly showed relatively low efficiency.These findings stress the need for assessing forest restoration outcomes from both ecological and cost perspectives,and can offer valuable insights for optimizing the layout of forest restoration initiatives in the UYRB.
文摘The goal of the present work is to demonstrate the potential of Artificial Neural Network(ANN)-driven Genetic Algorithm(GA)methods for energy efficiency and economic performance optimization of energy efficiency measures in a multi-family house building in Greece.The energy efficiency measures include different heating/cooling systems(such as low-temperature and high-temperature heat pumps,natural gas boilers,split units),building envelope components for floor,walls,roof and windows of variable heat transfer coefficients,the installation of solar thermal collectors and PVs.The calculations of the building loads and investment and operating and maintenance costs of the measures are based on the methodology defined in Directive 2010/31/EU,while economic assumptions are based on EN 15459-1 standard.Typically,multi-objective optimization of energy efficiency measures often requires the simulation of very large numbers of cases involving numerous possible combinations,resulting in intense computational load.The results of the study indicate that ANN-driven GA methods can be used as an alternative,valuable tool for reliably predicting the optimal measures which minimize primary energy consumption and life cycle cost of the building with greatly reduced computational requirements.Through GA methods,the computational time needed for obtaining the optimal solutions is reduced by 96.4%-96.8%.
基金Supported by the National Natural Science Foundation of China(Grant Nos.12361040,12061064)the National Science Foundation of Gansu Province(Grant No.22JR5RA264)State Scholarship Fund(Grant No.20230862021).
文摘In this article,we show the existence,uniqueness and stability of bounded solutions to the following quasilinear problems with mean curvature operator(φ'(x′(t)))′=f(t,x),t≥t_(0),lim_(t→∞)x(t)=ψ_(0),lim_(t→∞)x′(t)e^(t)=0,where t_(0) and ψ_(0) are real constants,φ(s)=s/√1−s^(2),s∈R with s∈(−1,1),f:[t_(0),∞)×R→R satisfies the Lipschitz or Osgood-type conditions.
文摘Composite resin restorations are routinely exposed to acidic and chromogenic beverages that may alter their surface integrity over time.This in-vitro study evaluated the surface roughness behavior of two universal single-shade(Unishade)composites and two conventionalmulti-shade composites following immersion in commonly consumed staining solutions and assessed whether repolishing could restore smoothness after degradation.A total of 120 standardized disc specimens were fabricated and allocated to fourmaterial groups,with each group subdivided into distilled water,cola,and coffee immersion subgroups.Surface roughness was recorded at baseline,after one week,after one month,and following a final repolishing step using a standardized multi-step system.The findings demonstrated that Unishade composites exhibited more stable surface characteristics across all immersion periods,with changes consistently remaining below the threshold associated with biofilm accumulation.Conventional composites showed greater variability,particularly in cola,where roughness values increased significantly compared with distilled water and coffee.Repolishing substantially reduced immersion-induced roughness in all materials,although its effectiveness varied depending on composite formulation and beverage acidity.Cola produced the greatest surface alterations across all groups,highlighting the erosive potential of low-pH beverages.These results indicate that Unishade composites possess superior resistance to surface degradation,likely due to their nano-structured filler configuration and less hydrophilic resin matrices,while conventional materials appear more susceptible to acidic challenge.Within the limitations of this study,selecting surface-stable material types and applying appropriate finishing and repolishing protocols may enhance the long-term performance and esthetics of composite restorations.
