The story goes back to the end of 2007, when Yang Min, Party secretary and deputy chief manager of theNantong Times Clothing Co., Ltd. in Rugao, Jiangsu Province, heard what had happened to an orphan in the city.
This paper gives integer linear programming models for scheduling doubles tennis group competitions. The goal is to build a fair and competitive schedule for all players. Our basic model achieves that for each player ...This paper gives integer linear programming models for scheduling doubles tennis group competitions. The goal is to build a fair and competitive schedule for all players. Our basic model achieves that for each player the average ranking of his partners in all matches is as close as possible to the average ranking of his opponents in all matches. One of the variations of the basic model provides that each matchup is fair and competitive. We also give models for the case when the number of players is 4n<span style="font-family:;" "=""> </span><span style="font-family:;" "="">+</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">2, and thus one of the matches has to be singles. Our models were implemented and tested using optimization software AMPL. Computational results along with schedules for some typical situations are also given the paper.</span>展开更多
The dynamic thermal process during double-sided asymmetrical TIG backing welding of large thick plates （ 1 000 mm×700 mm×50 mm） is numerically simulated using MSC. MARC. The effect of arc distance on the t...The dynamic thermal process during double-sided asymmetrical TIG backing welding of large thick plates （ 1 000 mm×700 mm×50 mm） is numerically simulated using MSC. MARC. The effect of arc distance on the thermal cycle in weld zone during double-sided asymmetrical T1G backing welding is investigated. The results show that the workpiece experiences double-peak thermal cycle in double-sided asymmetrical TIG backing welding. On the one hand, the fore arc has the pre- heating effect on the rear pass, and the pre-heating temperature depends on the distance between the double arcs, the heat input of fore arc, and the initial temperature of workpiece. On the other hand, the rear arc has the post-heating effect on the fore pass. The mutual effects of two heat sources decrease with the increase of arc distance.展开更多
For a field k and two finite groups G and X, when G acts on X from the right by group automorphisms, there is a Hopf algebra structure on k-space （kX°P）＊ kG （see Theorem 2.1）, called a non-balanced quantum ...For a field k and two finite groups G and X, when G acts on X from the right by group automorphisms, there is a Hopf algebra structure on k-space （kX°P）＊ kG （see Theorem 2.1）, called a non-balanced quantum double and denoted by Dx（G）. In this paper, some Hopf algebra properties of Dx （G） are given, the representation types of Dx （G） viewed as a k-algebra are discussed, the algebra structure and module category over Dx（G） are studied. Since the Hopf algebra structure of non-balanced quantum double DX （G） generMizes the usual quantum double D（G） for a finite group G, all results about Dx（G） in this paper can also be used to describe D（G） as a special case and the universal R-matrix of Dx （G） provides more solutions of Yang-Baxter equation.展开更多
In this article,we investigate the representations of the Drinfeld doubles D(Rmn(q))of the Radford Hopf algebras Rmn(q)over an algebraically closed field k,where m>1 and n>1 are integers and q∈k is a root of un...In this article,we investigate the representations of the Drinfeld doubles D(Rmn(q))of the Radford Hopf algebras Rmn(q)over an algebraically closed field k,where m>1 and n>1 are integers and q∈k is a root of unity of order n.Under the assumption char(k)■mn,all the finite-dimensional indecomposable modules over D(Rmn(q))are displayed and classified up to isomorphism.The Auslander-Reiten sequences in the category of finite-dimensional D(Rmn(q))-modules are also all displayed.It is shown that D(Rmn(q))is of tame representation type.展开更多
Through-silicon vias(TSVs)are crucial to the heterogeneous integration of multi-functional chiplets,providing highperformance vertical interconnects between different device layers.In this work,we introduce a novel TS...Through-silicon vias(TSVs)are crucial to the heterogeneous integration of multi-functional chiplets,providing highperformance vertical interconnects between different device layers.In this work,we introduce a novel TSV fabrication technology based on double-sided processing of polyimide-Ni(PI-Ni)functional layers,which can greatly simplify the TSV manufacturing flow,accompanying by advantages in improving TSV performance and reliability by effectively eliminating Cu contamination and significantly reducing leakage current.The key advancements of this approach include:(i)the complete coverage of the substrate with through-holes by the optimized double-sided PI insulation layer deposition process,where the chemical mechanical polishing(CMP)is carried out prior to the TSV metallization thus preventing substrate exposure to metallic contaminants;(ii)the deposition of a continuous Ni layer through an optimized double-sided electroless plating process,serving as both the barrier and the seed layer with high step coverage,enabling the simultaneous electroplating of TSV Cu conductors and double-sided redistribution layers(RDLs);and(iii)the demonstration of simulations and experimental validations highlighting improved thermomechanical stress distribution and superior electrical performance,including reduced parasitic capacitance and ultralow leakage current.The engineered PI-Ni-based TSV fabrication technology offers a contamination-free Cuinterconnect solution for advanced post-Moore applications such as hetero-integrated microsystems containing IC chips and MEMS devices.展开更多
NiFe-layered double hydroxides(NiFe-LDHs)are among the most promising earth-abundant electrocatalysts for the oxygen evolution reaction(OER)in alkaline media.However,their practical application is hindered by intrinsi...NiFe-layered double hydroxides(NiFe-LDHs)are among the most promising earth-abundant electrocatalysts for the oxygen evolution reaction(OER)in alkaline media.However,their practical application is hindered by intrinsic activity limitations and poor stability,primarily due to the asymmetric adsorption of oxygen intermediates.To overcome this,the binding strength must be synergistically tuned to a moderate level to optimize catalytic performance.Here,we engineered NiFeCoCr LDH through Co doping to enhance electrical conductivity and controlled Cr leaching to introduce cationic vacancies for modulating intermediate binding strength in NiFe LDH.X-ray absorption near-edge structure and extended X-ray absorption fine structure analyses reveal that NiFe-LDH with Co doping and Cr vacancies modulates the Ni oxidation state and local coordination environment,leading to a balanced electronic structure and enhanced structural complexity around the Ni sites.Additionally,these vacancies can trap OH^(-)/H_(2)O species,which can serve as a reservoir for OH^(-) transfer,facilitating the rapid formation of OER intermediates and enhancing catalytic performance at high current densities.As a result,V_(Cr)-NiFeCo LDH achieves 1.6 A cm^(-2)current density at 1.7 V vs.RHE while maintaining stable operation for over 1000 h at 500 mA cm^(-2).Density functional theory(DFT)calculations validate the synergistic effects of Co doping and Cr-induced vacancies on intermediate binding energies and improved OER kinetics.Overall,this work presents a rational design strategy to simultaneously enhance the activity and durability of NiFe-based OER catalysts for their application in high-performance alkaline water electrolysis.展开更多
In modern ZnO varistors,traditional aging mechanisms based on increased power consumption are no longer relevant due to reduced power consumption during DC aging.Prolonged exposure to both AC and DC voltages results i...In modern ZnO varistors,traditional aging mechanisms based on increased power consumption are no longer relevant due to reduced power consumption during DC aging.Prolonged exposure to both AC and DC voltages results in increased leakage current,decreased breakdown voltage,and lower nonlinearity,ultimately compromising their protective performance.To investigate the evolution in electrical properties during DC aging,this work developed a finite element model based on Voronoi networks and conducted accelerated aging tests on commercial varistors.Throughout the aging process,current-voltage characteristics and Schottky barrier parameters were measured and analyzed.The results indicate that when subjected to constant voltage,current flows through regions with larger grain sizes,forming discharge channels.As aging progresses,the current focus increases on these channels,leading to a decline in the varistor’s overall performance.Furthermore,analysis of the Schottky barrier parameters shows that the changes in electrical performance during aging are non-monotonic.These findings offer theoretical support for understanding the aging mechanisms and condition assessment of modern stable ZnO varistors.展开更多
The doubled haploid(DH)technique accelerates homozygosity by inducing chromosome doubling in haploid embryos derived from hybrid plants.This approach offers significant advantages over conventional rice breeding metho...The doubled haploid(DH)technique accelerates homozygosity by inducing chromosome doubling in haploid embryos derived from hybrid plants.This approach offers significant advantages over conventional rice breeding methods by shortening the breeding cycle and enabling rapid development of pure homozygous lines.Anther culture(AC)has been established as an efficient and successful method for producing DH plants via androgenesis in rice.However,despite its success in japonica rice.展开更多
The Double Take column looks at a single topic from an African and Chinese perspective.This month,we weigh the advantages of taking on debt against the benefits of staying debt-free.
Zeolite imidazolate framework(ZIF)-derived bimetallic sulfides and layered double hydroxides(LDHs)have emerged as promising electrode materials for supercapacitors,owing to their porous layered structures,high electro...Zeolite imidazolate framework(ZIF)-derived bimetallic sulfides and layered double hydroxides(LDHs)have emerged as promising electrode materials for supercapacitors,owing to their porous layered structures,high electrochemical activity,tun-able molecular architectures,low cost,and high specific capacitance.In this study,a unique composite material comprising ZIF-derived ZnCo bimetallic sulfide and LDH with a honeycomb-like structure was in situ grown on nickel foil(NF)via a con-trolled self-sacrificial template strategy.In contrast to previous reports,the resulting ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF compos-ite integrates the advantages of MXene,LDH,and sulfides,leading to significantly enhanced conductivity,structural stability,and catalytic activity.The ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF electrode exhibits a uniform network structure with a thickness of approximately 1μm coated on NF,and delivers a high specific capacitance of 1356.1 F·g^(-1)at a current density of 2 A·g^(-1).Further-more,an asymmetric supercapacitor assembled with ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF as the positive electrode and activated car-bon as the negative electrode achieves a high energy density of 34.08 Wh·kg^(-1)and a power density of 742.3 W·kg^(-1)at 1 A·g^(-1).This device successfully powers LED lights for 5 min,demonstrating its practical applicability.These results underscore the out-standing electrochemical performance of the ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF electrode,highlighting its potential for applica-tions in supercapacitors and related energy storage fields.展开更多
Artificial photosynthesis of hydrogen peroxide(H_(2)O_(2))from earth-abundant water and oxygen is a sustainable approach,however current photocatalysts suffer from low production rate and solar-to-chemical conversion ...Artificial photosynthesis of hydrogen peroxide(H_(2)O_(2))from earth-abundant water and oxygen is a sustainable approach,however current photocatalysts suffer from low production rate and solar-to-chemical conversion efficiency(<1.5%).Herein,we report that nickelchromium layered double hydroxide with intercalated nitrate(NiCrOOH-NO_(3))and a thickness of~4.4 nm is an efficient photocatalyst,enabling a H_(2)O_(2)production yield of 28.7 mmol g^(-1)h^(-1)under visible light irradiation with3.92%solar-to-chemical conversion efficiency.Experimental and computational studies have revealed an inherent facet-dependent reduction-oxidation reaction behavior and spatial separation of photogenerated electrons and holes.An unexpected role of intercalated nitrate is demonstrated,which promotes excited electron—hole spatial separation and facilitates the electron transfer to oxygen intermediate via delocalization.This work provides understandings in the impact of nanostructure and anion in the design of advanced photocatalysts,paving the way toward practical synthesis of H_(2)O_(2)using fully solar-driven renewable energy.展开更多
The buoyancy-induced flow constitutes a core scientific issue for thermal management of electronic devices and thermal design of energy systems,where accurate characterization of flow and heat transfer is essential to...The buoyancy-induced flow constitutes a core scientific issue for thermal management of electronic devices and thermal design of energy systems,where accurate characterization of flow and heat transfer is essential to improve thermal efficiency.In this work,buoyancy-induced flow above two heating elements flush-mounted at the bottom of a square enclosure containing air is numerically investigated over a range of Rayleigh numbers(0<Ra≤1.5×10^(8)),with a focus on equal and unequal heat flux conditions under a constraint of constant total thermal energy input.Distinct flow transitions are observed in both cases,leading to the identification of three flow regimes:Steady,periodic unsteady,and chaotic unsteady.Two types of periodic flows are distinguished,in which the first is a periodic flow dominated by a fundamental frequency(FF)and its integer-multiple frequencies(INTMF),while the second is a more complex periodic flow featuring FF,INTMF,and their sub-harmonics.The transitions between these regimes are affected by the relative heat flux of the two heaters.When the heat flux of the two heaters is unequal,the range of Rayleigh numbers corresponding to periodic flow is suppressed.It is also found that the time-averaged maximum temperature of the strong heater increases more rapidly with Ra,while that of the weak heater increases more slowly,reflecting the interaction between buoyancy-driven flow dynamics and asymmetric heat input.Analysis of the time-averaged Nusselt number demonstrates that heat dissipation from the isothermal walls remains roughly equivalent,even when the heat flux of the two heaters differs by a factor of two.These findings highlight the critical roles of Rayleigh number,the number of heaters,and the heat flux ratio of the heaters in determining heat transfer and flow characteristics for buoyancy-driven convection systems,providing important theoretical support and design references for engineering scenarios such as electronic devices and design of new energy systems.展开更多
The development of aqueous zinc batteries(AZBs)is severely constrained by uncontrolled dendrite growth and parasitic interfacial reactions.Conventional solvation-dominated additives can mitigate these issues by alteri...The development of aqueous zinc batteries(AZBs)is severely constrained by uncontrolled dendrite growth and parasitic interfacial reactions.Conventional solvation-dominated additives can mitigate these issues by altering the Zn^(2+)solvation structure,but they often compromise ion transport.Here,we introduce a molecular design principle for a non-solvating additive(NSA)based on inductive effects.Ethyl trifluoroacetate(ETFA),obtained by introducing an electron-withdrawing–CF_(3) group adjacent to the–C=O moiety of ethyl acetate(EA),participates minimally in the solvation structure but preferentially undergoes Gibbs adsorption at the Zn-electrolyte interface.This process reduces interfacial tension,reconstructs the electrical double layer,and orients ETFA molecules such that the hydrophilic–C=O groups face the electrolyte,modulating hydrogen-bonding networks,while the hydrophobic–CF_(3) groups anchor onto Zn to regulate deposition.As a result,dendrite formation and side reactions are simultaneously suppressed.With only 1 vol%ETFA,Zn-Cu cells achieve over 4000 stable cycles with 99.89%Coulombic efficiency.Zn-I_(2) full cells employing the modified electrolyte maintain stable operation for more than 500 cycles(6.8 mg cm^(-2),10μm Zn,N/P=2.86),and 0.3 Ah Zn-I_(2) pouch cells(30 mg cm^(-2),100μm Zn)can cycle stably for over 200 cycles.These findings highlight the critical role of Gibbs adsorption in interfacial regulation and provide insights for the molecular design of high-performance additives for stable Zn anodes.展开更多
We investigate the constrained fractional Choquard equation■where m>0,N>2s with s∈(0,1)being the order of the fractional Laplacian operator and I_(α)forα∈(0,N)denotes the Riesz potential.The parameterμ∈ℝa...We investigate the constrained fractional Choquard equation■where m>0,N>2s with s∈(0,1)being the order of the fractional Laplacian operator and I_(α)forα∈(0,N)denotes the Riesz potential.The parameterμ∈ℝappears as a Lagrange multiplier.By imposing general mass-supercritical conditions on F,we confirm the existence of normalized solutions that characterize the global minimizer on the Pohozaev manifold.Our proof does not depend on the assumption that all weak solutions satisfy the Pohozaev identity,a challenge that remains unsolved for this doubly nonlocal equation.展开更多
Inclusive green growth(IGG)is a crucial pathway to high-quality economic development,with standardization serving as a key enabler.Standardization plays a critical role in reducing coordination costs and improving res...Inclusive green growth(IGG)is a crucial pathway to high-quality economic development,with standardization serving as a key enabler.Standardization plays a critical role in reducing coordination costs and improving resource allocation efficiency by facilitating rule harmonization,factor integration,and collaborative governance.Examining IGG from a standardization perspective helps clarify the mechanisms through which economic,environmental,and social objectives can be jointly realized,and offers new insights into the institutionalized and sustainable pursuit of multiple development goals.However,how standardization promotes IGG by coordinating economic growth,environmental performance,and social equity remains insufficiently explored in the existing literature.Using panel data from 283 prefecture-level Chinese cities(2012-2021),this study treats the comprehensive standardization reform pilot as a quasi-natural experiment and applies a double machine-learning framework to test whether standardization promotes IGG.The analysis further explores the mediating roles of technological innovation,green finance,and employment quality,and examines heterogeneity across geographic location,resource endowment,industrial base,and city hierarchy.It also evaluates the regional coordination effects of standardization.Results show that standardization significantly advances IGG,though its impact varies by regional and structural characteristics.Standardization enhances IGG by strengthening innovation,expanding green finance,and improving job quality.Moreover,it helps bridge geographic divides,narrow interregional disparities,and enhance coordination.These findings offer empirical evidence for policymakers to design targeted standardization strategies that support sustainable and equitable urban development.展开更多
Ferroptosis plays a key role in nerve injury in intracerebral hemorrhage and is associated with the upregulation of murine double minute 2.Investigating the mechanism underlying murine double minute 2-related ferropto...Ferroptosis plays a key role in nerve injury in intracerebral hemorrhage and is associated with the upregulation of murine double minute 2.Investigating the mechanism underlying murine double minute 2-related ferroptosis could help identify new therapies for intracerebral hemorrhage.An in vitro intracerebral hemorrhage model was established by treating BV2 microglial cells with oxygen-glucose deprivation combined with hemin.The role of murine double minute 2 in regulating ferroptosis was investigated via transduction with RNA interference and lentivirus overexpression.Furthermore,intracerebral hemorrhage mouse models were constructed with and without an murine double minute 2 inhibitor(brigimadlin),and behavioral assays were performed to assess the learning ability and cognitive function.Murine double minute 2 dysregulation was associated with oxygen-glucose deprivation combined with hemin-induced BV2 microglial cell ferroptosis and M1/M2 polarization.The results suggested that murine double minute 2 induced glutathione peroxidase 4 ubiquitination and degradation to regulate ferroptosis and inflammatory responses in BV2 microglial cells.Mechanistically,Wilms tumor 1-associated protein induced murine double minute 2 N6-methyladenosine(m6A)modification and regulated ferroptosis and inflammatory responses.In vivo analysis showed that brigimadlin improved neurological deficits and spatial memory in mice with intracerebral hemorrhage.In summary,the results indicate that Wilms tumor 1-associated protein regulates murine double minute 2 m6A modification,and murine double minute 2 induces glutathione peroxidase 4 ubiquitination and degradation.This regulation promotes ferroptosis and inflammatory responses in oxygen-glucose deprivation combined with hemin-induced BV2 microglial cells,suggesting that the murine double minute 2-glutathione peroxidase 4-ferroptosis regulatory axis exerts neurotoxic effects.These findings identify glutathione peroxidase 4 as a potential gene therapy target for intracerebral hemorrhage-related brain injury.展开更多
NiFe layered double hydroxide(NiFe LDH)has emerged as a promising catalyst for the oxygen evolution reaction(OER);however,its hydrogen evolution reaction(HER)activity remains suboptimal due to unfavorable electronic s...NiFe layered double hydroxide(NiFe LDH)has emerged as a promising catalyst for the oxygen evolution reaction(OER);however,its hydrogen evolution reaction(HER)activity remains suboptimal due to unfavorable electronic structures,particularly the d-electron density of metal sites,which impede water dissociation and lead to poor hydrogen adsorption/desorption capabilities.Herein,we introduce an efficient cooperative d-electron density regulation(CDDR)engineering to comprehensively optimize the delectron density of NiFe LDH by grafting MoO_(x) -modified NiFe LDH nanosheets onto porous nickel particles(PNPs).The PNPs facilitate d-electron density modulation along the edges of the nanosheets,while the MoO_(x) species enable d-electron density modulation across the plane of the nanosheets,thus cooperatively constructing enriched d-electron density in NiFe LDH.Theoretical studies validate the CDDR process and reveal that the enriched d-electron density accelerates water dissociation and optimizes the hydrogen adsorption behavior of NiFe LDH.As a result,the engineered catalyst exhibits significantly improved HER activity,achieving an ultra-low overpotential of 38 mV at 10 mA cm^(-2)in 1 M KOH.Additionally,the CDDR-optimized catalyst also exhibits good OER performance,demonstrating excellent bifunctional performance for overall water splitting in both alkaline freshwater and seawater electrolytes.This work presents a novel CDDR strategy for engineering NiFe LDH into efficient HER catalysts without compromising its OER activity,potentially paving the way for the development of active and robust electrocatalysts for sustainable energy applications.展开更多
文摘The story goes back to the end of 2007, when Yang Min, Party secretary and deputy chief manager of theNantong Times Clothing Co., Ltd. in Rugao, Jiangsu Province, heard what had happened to an orphan in the city.
文摘This paper gives integer linear programming models for scheduling doubles tennis group competitions. The goal is to build a fair and competitive schedule for all players. Our basic model achieves that for each player the average ranking of his partners in all matches is as close as possible to the average ranking of his opponents in all matches. One of the variations of the basic model provides that each matchup is fair and competitive. We also give models for the case when the number of players is 4n<span style="font-family:;" "=""> </span><span style="font-family:;" "="">+</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">2, and thus one of the matches has to be singles. Our models were implemented and tested using optimization software AMPL. Computational results along with schedules for some typical situations are also given the paper.</span>
文摘The dynamic thermal process during double-sided asymmetrical TIG backing welding of large thick plates （ 1 000 mm×700 mm×50 mm） is numerically simulated using MSC. MARC. The effect of arc distance on the thermal cycle in weld zone during double-sided asymmetrical T1G backing welding is investigated. The results show that the workpiece experiences double-peak thermal cycle in double-sided asymmetrical TIG backing welding. On the one hand, the fore arc has the pre- heating effect on the rear pass, and the pre-heating temperature depends on the distance between the double arcs, the heat input of fore arc, and the initial temperature of workpiece. On the other hand, the rear arc has the post-heating effect on the fore pass. The mutual effects of two heat sources decrease with the increase of arc distance.
基金Supported by Doctoral Foundation of Qingdao University of Science and Technology (20080022398)the National Natural Science Foundation of China (11271318, 11171296)the Specialized Research Fund for the Doctoral Program of Higher Education of China (20110101110010)
文摘For a field k and two finite groups G and X, when G acts on X from the right by group automorphisms, there is a Hopf algebra structure on k-space （kX°P）＊ kG （see Theorem 2.1）, called a non-balanced quantum double and denoted by Dx（G）. In this paper, some Hopf algebra properties of Dx （G） are given, the representation types of Dx （G） viewed as a k-algebra are discussed, the algebra structure and module category over Dx（G） are studied. Since the Hopf algebra structure of non-balanced quantum double DX （G） generMizes the usual quantum double D（G） for a finite group G, all results about Dx（G） in this paper can also be used to describe D（G） as a special case and the universal R-matrix of Dx （G） provides more solutions of Yang-Baxter equation.
基金supported by National Natural Science Foundation of China(Grant Nos.12201545 and 12071412)。
文摘In this article,we investigate the representations of the Drinfeld doubles D(Rmn(q))of the Radford Hopf algebras Rmn(q)over an algebraically closed field k,where m>1 and n>1 are integers and q∈k is a root of unity of order n.Under the assumption char(k)■mn,all the finite-dimensional indecomposable modules over D(Rmn(q))are displayed and classified up to isomorphism.The Auslander-Reiten sequences in the category of finite-dimensional D(Rmn(q))-modules are also all displayed.It is shown that D(Rmn(q))is of tame representation type.
基金supported by the National Natural Science Foundation of China under grants 92373105,62404019,and 62074015.
文摘Through-silicon vias(TSVs)are crucial to the heterogeneous integration of multi-functional chiplets,providing highperformance vertical interconnects between different device layers.In this work,we introduce a novel TSV fabrication technology based on double-sided processing of polyimide-Ni(PI-Ni)functional layers,which can greatly simplify the TSV manufacturing flow,accompanying by advantages in improving TSV performance and reliability by effectively eliminating Cu contamination and significantly reducing leakage current.The key advancements of this approach include:(i)the complete coverage of the substrate with through-holes by the optimized double-sided PI insulation layer deposition process,where the chemical mechanical polishing(CMP)is carried out prior to the TSV metallization thus preventing substrate exposure to metallic contaminants;(ii)the deposition of a continuous Ni layer through an optimized double-sided electroless plating process,serving as both the barrier and the seed layer with high step coverage,enabling the simultaneous electroplating of TSV Cu conductors and double-sided redistribution layers(RDLs);and(iii)the demonstration of simulations and experimental validations highlighting improved thermomechanical stress distribution and superior electrical performance,including reduced parasitic capacitance and ultralow leakage current.The engineered PI-Ni-based TSV fabrication technology offers a contamination-free Cuinterconnect solution for advanced post-Moore applications such as hetero-integrated microsystems containing IC chips and MEMS devices.
基金supported by the Natural Science Foundation of China Grant No.52272289 and 5240223,and JSPS(Japan Society for the Promotion of Science)of Grant No.22K19088,23H00313,24H02202,and 24H02205。
文摘NiFe-layered double hydroxides(NiFe-LDHs)are among the most promising earth-abundant electrocatalysts for the oxygen evolution reaction(OER)in alkaline media.However,their practical application is hindered by intrinsic activity limitations and poor stability,primarily due to the asymmetric adsorption of oxygen intermediates.To overcome this,the binding strength must be synergistically tuned to a moderate level to optimize catalytic performance.Here,we engineered NiFeCoCr LDH through Co doping to enhance electrical conductivity and controlled Cr leaching to introduce cationic vacancies for modulating intermediate binding strength in NiFe LDH.X-ray absorption near-edge structure and extended X-ray absorption fine structure analyses reveal that NiFe-LDH with Co doping and Cr vacancies modulates the Ni oxidation state and local coordination environment,leading to a balanced electronic structure and enhanced structural complexity around the Ni sites.Additionally,these vacancies can trap OH^(-)/H_(2)O species,which can serve as a reservoir for OH^(-) transfer,facilitating the rapid formation of OER intermediates and enhancing catalytic performance at high current densities.As a result,V_(Cr)-NiFeCo LDH achieves 1.6 A cm^(-2)current density at 1.7 V vs.RHE while maintaining stable operation for over 1000 h at 500 mA cm^(-2).Density functional theory(DFT)calculations validate the synergistic effects of Co doping and Cr-induced vacancies on intermediate binding energies and improved OER kinetics.Overall,this work presents a rational design strategy to simultaneously enhance the activity and durability of NiFe-based OER catalysts for their application in high-performance alkaline water electrolysis.
文摘In modern ZnO varistors,traditional aging mechanisms based on increased power consumption are no longer relevant due to reduced power consumption during DC aging.Prolonged exposure to both AC and DC voltages results in increased leakage current,decreased breakdown voltage,and lower nonlinearity,ultimately compromising their protective performance.To investigate the evolution in electrical properties during DC aging,this work developed a finite element model based on Voronoi networks and conducted accelerated aging tests on commercial varistors.Throughout the aging process,current-voltage characteristics and Schottky barrier parameters were measured and analyzed.The results indicate that when subjected to constant voltage,current flows through regions with larger grain sizes,forming discharge channels.As aging progresses,the current focus increases on these channels,leading to a decline in the varistor’s overall performance.Furthermore,analysis of the Schottky barrier parameters shows that the changes in electrical performance during aging are non-monotonic.These findings offer theoretical support for understanding the aging mechanisms and condition assessment of modern stable ZnO varistors.
基金supported by the Science and Technology Innovation Program of Fujian Agriculture and Forestry University,China(Grant No.KFB22045)the General Program of Natural Science Foundation Fujian,China(Grant No.2023J01460).
文摘The doubled haploid(DH)technique accelerates homozygosity by inducing chromosome doubling in haploid embryos derived from hybrid plants.This approach offers significant advantages over conventional rice breeding methods by shortening the breeding cycle and enabling rapid development of pure homozygous lines.Anther culture(AC)has been established as an efficient and successful method for producing DH plants via androgenesis in rice.However,despite its success in japonica rice.
文摘The Double Take column looks at a single topic from an African and Chinese perspective.This month,we weigh the advantages of taking on debt against the benefits of staying debt-free.
基金support by NSFC(No.61704047)Natural Science Foundation of Henan Province(No.242300420271)Key Research Project of Henan Provincial Higher Education(No.24A430008).
文摘Zeolite imidazolate framework(ZIF)-derived bimetallic sulfides and layered double hydroxides(LDHs)have emerged as promising electrode materials for supercapacitors,owing to their porous layered structures,high electrochemical activity,tun-able molecular architectures,low cost,and high specific capacitance.In this study,a unique composite material comprising ZIF-derived ZnCo bimetallic sulfide and LDH with a honeycomb-like structure was in situ grown on nickel foil(NF)via a con-trolled self-sacrificial template strategy.In contrast to previous reports,the resulting ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF compos-ite integrates the advantages of MXene,LDH,and sulfides,leading to significantly enhanced conductivity,structural stability,and catalytic activity.The ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF electrode exhibits a uniform network structure with a thickness of approximately 1μm coated on NF,and delivers a high specific capacitance of 1356.1 F·g^(-1)at a current density of 2 A·g^(-1).Further-more,an asymmetric supercapacitor assembled with ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF as the positive electrode and activated car-bon as the negative electrode achieves a high energy density of 34.08 Wh·kg^(-1)and a power density of 742.3 W·kg^(-1)at 1 A·g^(-1).This device successfully powers LED lights for 5 min,demonstrating its practical applicability.These results underscore the out-standing electrochemical performance of the ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF electrode,highlighting its potential for applica-tions in supercapacitors and related energy storage fields.
基金support from the National Natural Science Foundation of China(NSFC 21905092,22475072 and 22075085)the Fundamental Research Funds for the Central Universities+1 种基金supported by the Shanghai Frontiers Science Center of Molecule Intelligent SynthesesEast China Normal University Multifunctional Platform for Innovation(004)。
文摘Artificial photosynthesis of hydrogen peroxide(H_(2)O_(2))from earth-abundant water and oxygen is a sustainable approach,however current photocatalysts suffer from low production rate and solar-to-chemical conversion efficiency(<1.5%).Herein,we report that nickelchromium layered double hydroxide with intercalated nitrate(NiCrOOH-NO_(3))and a thickness of~4.4 nm is an efficient photocatalyst,enabling a H_(2)O_(2)production yield of 28.7 mmol g^(-1)h^(-1)under visible light irradiation with3.92%solar-to-chemical conversion efficiency.Experimental and computational studies have revealed an inherent facet-dependent reduction-oxidation reaction behavior and spatial separation of photogenerated electrons and holes.An unexpected role of intercalated nitrate is demonstrated,which promotes excited electron—hole spatial separation and facilitates the electron transfer to oxygen intermediate via delocalization.This work provides understandings in the impact of nanostructure and anion in the design of advanced photocatalysts,paving the way toward practical synthesis of H_(2)O_(2)using fully solar-driven renewable energy.
基金supported by the Tianjin Education Commission Research Program Project(No.2024KJ105)。
文摘The buoyancy-induced flow constitutes a core scientific issue for thermal management of electronic devices and thermal design of energy systems,where accurate characterization of flow and heat transfer is essential to improve thermal efficiency.In this work,buoyancy-induced flow above two heating elements flush-mounted at the bottom of a square enclosure containing air is numerically investigated over a range of Rayleigh numbers(0<Ra≤1.5×10^(8)),with a focus on equal and unequal heat flux conditions under a constraint of constant total thermal energy input.Distinct flow transitions are observed in both cases,leading to the identification of three flow regimes:Steady,periodic unsteady,and chaotic unsteady.Two types of periodic flows are distinguished,in which the first is a periodic flow dominated by a fundamental frequency(FF)and its integer-multiple frequencies(INTMF),while the second is a more complex periodic flow featuring FF,INTMF,and their sub-harmonics.The transitions between these regimes are affected by the relative heat flux of the two heaters.When the heat flux of the two heaters is unequal,the range of Rayleigh numbers corresponding to periodic flow is suppressed.It is also found that the time-averaged maximum temperature of the strong heater increases more rapidly with Ra,while that of the weak heater increases more slowly,reflecting the interaction between buoyancy-driven flow dynamics and asymmetric heat input.Analysis of the time-averaged Nusselt number demonstrates that heat dissipation from the isothermal walls remains roughly equivalent,even when the heat flux of the two heaters differs by a factor of two.These findings highlight the critical roles of Rayleigh number,the number of heaters,and the heat flux ratio of the heaters in determining heat transfer and flow characteristics for buoyancy-driven convection systems,providing important theoretical support and design references for engineering scenarios such as electronic devices and design of new energy systems.
基金financially supported by the Science and Technology Foundation of Henan Province(252102230017)the Doctoral Foundation of Henan University of Technology(2019BS005)+2 种基金the Talent Research Start-up Fund Project of Tongling University(2021tlxyrc23)the Natural Science Research Project of the Anhui Educational Committee(2023AH040234)the Scientific Research Projects of Tongling University(2022tlxyszZD04)。
文摘The development of aqueous zinc batteries(AZBs)is severely constrained by uncontrolled dendrite growth and parasitic interfacial reactions.Conventional solvation-dominated additives can mitigate these issues by altering the Zn^(2+)solvation structure,but they often compromise ion transport.Here,we introduce a molecular design principle for a non-solvating additive(NSA)based on inductive effects.Ethyl trifluoroacetate(ETFA),obtained by introducing an electron-withdrawing–CF_(3) group adjacent to the–C=O moiety of ethyl acetate(EA),participates minimally in the solvation structure but preferentially undergoes Gibbs adsorption at the Zn-electrolyte interface.This process reduces interfacial tension,reconstructs the electrical double layer,and orients ETFA molecules such that the hydrophilic–C=O groups face the electrolyte,modulating hydrogen-bonding networks,while the hydrophobic–CF_(3) groups anchor onto Zn to regulate deposition.As a result,dendrite formation and side reactions are simultaneously suppressed.With only 1 vol%ETFA,Zn-Cu cells achieve over 4000 stable cycles with 99.89%Coulombic efficiency.Zn-I_(2) full cells employing the modified electrolyte maintain stable operation for more than 500 cycles(6.8 mg cm^(-2),10μm Zn,N/P=2.86),and 0.3 Ah Zn-I_(2) pouch cells(30 mg cm^(-2),100μm Zn)can cycle stably for over 200 cycles.These findings highlight the critical role of Gibbs adsorption in interfacial regulation and provide insights for the molecular design of high-performance additives for stable Zn anodes.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2022A1515012138)the NSFC(12271436,12371119)supported by the Natural Science Basic Research Program of Shaanxi(2022JC-04).
文摘We investigate the constrained fractional Choquard equation■where m>0,N>2s with s∈(0,1)being the order of the fractional Laplacian operator and I_(α)forα∈(0,N)denotes the Riesz potential.The parameterμ∈ℝappears as a Lagrange multiplier.By imposing general mass-supercritical conditions on F,we confirm the existence of normalized solutions that characterize the global minimizer on the Pohozaev manifold.Our proof does not depend on the assumption that all weak solutions satisfy the Pohozaev identity,a challenge that remains unsolved for this doubly nonlocal equation.
基金supported by the National Social Science Fund of China“Research on the Ecological Symbiotic Development and Dynamic Governance of Manufacturing Entrepreneurship Platform”[Grant No.22BGL048].
文摘Inclusive green growth(IGG)is a crucial pathway to high-quality economic development,with standardization serving as a key enabler.Standardization plays a critical role in reducing coordination costs and improving resource allocation efficiency by facilitating rule harmonization,factor integration,and collaborative governance.Examining IGG from a standardization perspective helps clarify the mechanisms through which economic,environmental,and social objectives can be jointly realized,and offers new insights into the institutionalized and sustainable pursuit of multiple development goals.However,how standardization promotes IGG by coordinating economic growth,environmental performance,and social equity remains insufficiently explored in the existing literature.Using panel data from 283 prefecture-level Chinese cities(2012-2021),this study treats the comprehensive standardization reform pilot as a quasi-natural experiment and applies a double machine-learning framework to test whether standardization promotes IGG.The analysis further explores the mediating roles of technological innovation,green finance,and employment quality,and examines heterogeneity across geographic location,resource endowment,industrial base,and city hierarchy.It also evaluates the regional coordination effects of standardization.Results show that standardization significantly advances IGG,though its impact varies by regional and structural characteristics.Standardization enhances IGG by strengthening innovation,expanding green finance,and improving job quality.Moreover,it helps bridge geographic divides,narrow interregional disparities,and enhance coordination.These findings offer empirical evidence for policymakers to design targeted standardization strategies that support sustainable and equitable urban development.
基金the National Natural Science Foundation of China,Nos.82311530117(to RJ),82260260(to FC).
文摘Ferroptosis plays a key role in nerve injury in intracerebral hemorrhage and is associated with the upregulation of murine double minute 2.Investigating the mechanism underlying murine double minute 2-related ferroptosis could help identify new therapies for intracerebral hemorrhage.An in vitro intracerebral hemorrhage model was established by treating BV2 microglial cells with oxygen-glucose deprivation combined with hemin.The role of murine double minute 2 in regulating ferroptosis was investigated via transduction with RNA interference and lentivirus overexpression.Furthermore,intracerebral hemorrhage mouse models were constructed with and without an murine double minute 2 inhibitor(brigimadlin),and behavioral assays were performed to assess the learning ability and cognitive function.Murine double minute 2 dysregulation was associated with oxygen-glucose deprivation combined with hemin-induced BV2 microglial cell ferroptosis and M1/M2 polarization.The results suggested that murine double minute 2 induced glutathione peroxidase 4 ubiquitination and degradation to regulate ferroptosis and inflammatory responses in BV2 microglial cells.Mechanistically,Wilms tumor 1-associated protein induced murine double minute 2 N6-methyladenosine(m6A)modification and regulated ferroptosis and inflammatory responses.In vivo analysis showed that brigimadlin improved neurological deficits and spatial memory in mice with intracerebral hemorrhage.In summary,the results indicate that Wilms tumor 1-associated protein regulates murine double minute 2 m6A modification,and murine double minute 2 induces glutathione peroxidase 4 ubiquitination and degradation.This regulation promotes ferroptosis and inflammatory responses in oxygen-glucose deprivation combined with hemin-induced BV2 microglial cells,suggesting that the murine double minute 2-glutathione peroxidase 4-ferroptosis regulatory axis exerts neurotoxic effects.These findings identify glutathione peroxidase 4 as a potential gene therapy target for intracerebral hemorrhage-related brain injury.
基金financially supported from the National Key Research and Development Program of China(2022YFB3803600)the National Natural Science Foundation of China(52301272,22309168,12564025,and 52472205)+7 种基金the Fundamental Research Funds for the Central Universities(CCNU25ZH006)the National College Student Innovation and Entrepreneurship Training Project(202510513082)the Research Program of HBNU(2025X082 and2025Y145)the Foundation of Hubei Key Laboratory of Photoelectric Materials and Devices(PMD202404)the General Program of Open Project of the State Key Laboratory of Precision Welding and Joining of Materials Structures(MSWJ-25M-18)the Key Research Project of Hubei Provincial Department of Education(No.D20252503)the Key Project of Hubei Provincial Natural Science Foundation of China(2025AFD002)the Foundation of National Laboratory of Solid State Microstructures(M37087)。
文摘NiFe layered double hydroxide(NiFe LDH)has emerged as a promising catalyst for the oxygen evolution reaction(OER);however,its hydrogen evolution reaction(HER)activity remains suboptimal due to unfavorable electronic structures,particularly the d-electron density of metal sites,which impede water dissociation and lead to poor hydrogen adsorption/desorption capabilities.Herein,we introduce an efficient cooperative d-electron density regulation(CDDR)engineering to comprehensively optimize the delectron density of NiFe LDH by grafting MoO_(x) -modified NiFe LDH nanosheets onto porous nickel particles(PNPs).The PNPs facilitate d-electron density modulation along the edges of the nanosheets,while the MoO_(x) species enable d-electron density modulation across the plane of the nanosheets,thus cooperatively constructing enriched d-electron density in NiFe LDH.Theoretical studies validate the CDDR process and reveal that the enriched d-electron density accelerates water dissociation and optimizes the hydrogen adsorption behavior of NiFe LDH.As a result,the engineered catalyst exhibits significantly improved HER activity,achieving an ultra-low overpotential of 38 mV at 10 mA cm^(-2)in 1 M KOH.Additionally,the CDDR-optimized catalyst also exhibits good OER performance,demonstrating excellent bifunctional performance for overall water splitting in both alkaline freshwater and seawater electrolytes.This work presents a novel CDDR strategy for engineering NiFe LDH into efficient HER catalysts without compromising its OER activity,potentially paving the way for the development of active and robust electrocatalysts for sustainable energy applications.
