Eu^(2+)-doped phosphors show broadband absorption,tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions,allowing them to be used in solid-state lighting.To expand their applications...Eu^(2+)-doped phosphors show broadband absorption,tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions,allowing them to be used in solid-state lighting.To expand their applications in other fields such as detection and sensing technologies,the Eu^(2+)emission needs to be tuned into the near-infrared region,but it is a big challenge to obtain Eu^(2+)near-infrared region emitters due to the absence of host compounds with extremely large crystal-field splitting.In this work,we chose M_(4)Li(BN_(2))_(3)(M=Ca,Sr,Ba)as a host and realize the near-infrared region emission of Eu^(2+)in it.Among these phosphors,Ba4Li(BN_(2))_(3):Eu^(2+)exhibits the longest emission of 880 nm and the largest full-width at half maximum of 276 nm under 450 nm excitation,while Ca_(4)Li(BN_(2))_(3):Eu^(2+)and Sr_(4)Li(BN_(2))_(3):Eu^(2+)emit at740 and 680 nm,respectively.We observe an interesting phenomenon that the energy shift of emission is linearly related to the radius difference between the alkaline earth cation and the activator Eu^(2+)in this system.展开更多
Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The ...Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The Co−30Ni−10Al−3V−6Ti−2Ta alloy,designed based onγʹphase dissolution temperature and phase fraction,was synthesized via arc melting and heat treatment.Phase transition temperatures,microstructure evolution,and hightemperature mechanical properties were characterized by differential scanning calorimetry,scanning electron microscopy,dual-beam TEM,and compression tests.Results show that the alloy has low density(8.15 g/cm^(3))and highγʹdissolution temperature(1234℃),along with unique yield strength retention from room temperature to 650℃.The yield strength anomaly(YSA)is attributed to high stacking fault energy and activation of the Kear−Wilsdorf locking mechanism,contributing to superior high-temperature stability of the alloy.The yield strength of this alloy outperforms other lowdensity Co-based superalloys in the temperature range of 23−650℃.展开更多
Enhancing the oxidation resistance of Co-based superalloys by adding a high content of Cr,while simultaneously ensuring the stability of theγ/γ′phases,presents a significant challenge.This study evaluated the alloy...Enhancing the oxidation resistance of Co-based superalloys by adding a high content of Cr,while simultaneously ensuring the stability of theγ/γ′phases,presents a significant challenge.This study evaluated the alloying potential of Co–30Ni–10Al–5V–4Ta using the CALPHAD method,revealing promising characteristics.The developed Co–30Ni–10Al–5V–4Ta–12Cr alloy characterized by high Cr content andγ/γ′two-phase structure,demonstrating highγ′solvus temperature of 1139℃,low density of 8.48 g/cm^(3),minimalγ/γ′lattice misfit of +0.28%,high compressive yield strength of 651 MPa at 800℃,and excellent oxidation resistance with a weight gain of 6.5 mg/cm^(3)after 200 h at 1000℃.Examination of the oxidation behavior at 1000℃ revealed an oxide layer consisting of a porous outer CoO,NiO,and V_(3)O_(4)(CNV)oxide and a denser inner mixed oxide layer comprising CoO,NiO,and V_(3)O_(4)(CNV)oxide,Al_(2)O_(3),Cr_(2)O_(3),CoO,and NiO(CNAC)oxide,and TaO_(2),CoO,and NiO(CNT)oxide.展开更多
Austenitic steel is a prime candidate for structural applications in extreme environments such as nuclear fusion reactors due to its favorable cryogenic mechanical properties.A heterogeneous microstructure was develop...Austenitic steel is a prime candidate for structural applications in extreme environments such as nuclear fusion reactors due to its favorable cryogenic mechanical properties.A heterogeneous microstructure was developed via cold rolling followed by short-term annealing,resulting in partially recrystallized regions interspersed with non-recrystallized regions in an austenitic stainless steel.A series of tensile tests conducted at both room temperature and 77 K,combined with digital image correlation,nanoindentation,electron backscatter diffraction,and transmission electron microscopy,were employed to investigate the strain partitioning and deformation mechanisms of the microstructure.The results reveal that at 77 K,the yield strength reaches 1330 MPa and the total elongation increases to 51.49%,surpassing the performance observed at the room temperature.The cryogenic environment reduces the stacking fault energy,thereby promoting the formation of stacking faults and deformation twins in the recrystallized regions.Concurrently,the non-recrystallized regions exhibit pronounced strain-induced martensitic transformation that enhances ductility through the transformation-induced plasticity effect.These synergistic interactions between the distinct microstructural regions underpin the remarkable strength-ductility balance of the steel under cryogenic conditions.展开更多
In the casting process of 1060 industrial pure aluminum,the inclusions in the aluminum melt significantly affect the product quality.In this study,the influence of refining temperature and the composition of salt flux...In the casting process of 1060 industrial pure aluminum,the inclusions in the aluminum melt significantly affect the product quality.In this study,the influence of refining temperature and the composition of salt fluxes on the purification effect and mechanical properties of aluminum melt was investigated.The results indicate that lower refining temperatures and modified salt fluxes can effectively enhance the cleanliness of the aluminum melt.As the refining temperature increases,the large inclusions gradually increase.The addition of16wt.%Na_(3)AlF_(6) can dissolve and break up Al_2O_(3) inclusions,facilitating the separation of the aluminum melt and aluminum slag.The addition of 16wt.%Na3AlF6 and 2wt.%CaCO_(3) to the basic salt fluxes enables gas refinement,thereby further improving the cleanliness of the aluminum melt.Under the refining condition of 37wt.%NaCl-47wt.%KCl--16wt.%Na3AIF3-2wt.%CaCO_(3) at 740℃,better cleanliness and mechanical properties were obtained.The cleanliness and yield strength are approximately 99.99928%and 71.46 MPa,respectively.This work can offer valuable reference and theoretical insights for future research.展开更多
The commercial viability of lithium-sulfur batteries is still challenged by the notorious lithium polysulfides(Li PSs)shuttle effect on the sulfur cathode and uncontrollable Li dendrites growth on the Li anode.Herein,...The commercial viability of lithium-sulfur batteries is still challenged by the notorious lithium polysulfides(Li PSs)shuttle effect on the sulfur cathode and uncontrollable Li dendrites growth on the Li anode.Herein,a bi-service host with Co-Fe binary-metal selenide quantum dots embedded in three-dimensional inverse opal structured nitrogen-doped carbon skeleton(3DIO FCSe-QDs@NC)is elaborately designed for both sulfur cathode and Li metal anode.The highly dispersed FCSe-QDs with superb adsorptive-catalytic properties can effectively immobilize the soluble Li PSs and improve diffusion-conversion kinetics to mitigate the polysulfide-shutting behaviors.Simultaneously,the 3D-ordered porous networks integrated with abundant lithophilic sites can accomplish uniform Li deposition and homogeneous Li-ion flux for suppressing the growth of dendrites.Taking advantage of these merits,the assembled Li-S full batteries with 3DIO FCSe-QDs@NC host exhibit excellent rate performance and stable cycling ability(a low decay rate of 0.014%over 2,000 cycles at 2C).Remarkably,a promising areal capacity of 8.41 mAh cm^(-2)can be achieved at the sulfur loading up to 8.50 mg cm^(-2)with an ultra-low electrolyte/sulfur ratio of 4.1μL mg^(-1).This work paves the bi-serve host design from systematic experimental and theoretical analysis,which provides a viable avenue to solve the challenges of both sulfur and Li electrodes for practical Li-S full batteries.展开更多
To solve the environmental pollution and low yield during the sythesis of zeolitic imidazolate frameworks(ZIFs)and their derived materials,a KOH-assisted aqueous strategy is proposed to synthesize cobalt zeolitic imid...To solve the environmental pollution and low yield during the sythesis of zeolitic imidazolate frameworks(ZIFs)and their derived materials,a KOH-assisted aqueous strategy is proposed to synthesize cobalt zeolitic imidazolate framework(ZIF-67)polyhedrons,which are used as precursors to prepare cobalt selenide/carbon composites with different crystal phases(Co_(0.85)Se,CoSe_2).When evaluated as anode material for lithium ion batteries,Co_(0.85)Se/C composites deliver a reversible capacity of 758.7 m A·h·g^(-1)with a capacity retention rate of 90.5%at 1.0 A·g^(-1)after 500 cycles,and the superior rate capability is 620 m A·h·g^(-1)at 2.0 A·g^(-1).The addition of KOH accelerates the production of ZIF-67 crystals by boosting deprotonation of dimethylimidazole,resulting in rapid growth and structures transition from two-dimensional to three-dimensional of ZIF-67 in aqueous solution,which greatly promotes the application of MOFs in the field of energy storage and conversion.展开更多
The organic carbon source coating LiFe_(x)Mn_(1-x)PO_(4)suffers from the problem of non-uniform carbon cladding.Too thick carbon cladding layer instead hinders the de-embedding of lithium ions.In this paper,we choose ...The organic carbon source coating LiFe_(x)Mn_(1-x)PO_(4)suffers from the problem of non-uniform carbon cladding.Too thick carbon cladding layer instead hinders the de-embedding of lithium ions.In this paper,we choose cornstalk as the carbon source,then LiFe_(0.5)Mn_(0.5)PO_(4)@cornstalk-C(LFMP@C-C)with 3D anchoring structure is prepared by the solvothermal method.The results show that the LFMP with cornstalk as the carbon source has better performance compared to the sucrose-coated LFMP material(LFMP@C).The discharge capacity of LFMP@C-C is 116 mAh/g for the first cycle at 1 C and the capacity retention rate is 94.0%after 500 cycles,and the discharge capacity of LFMP@C-C is more than 17.17%higher than that of LFMP@C.展开更多
Sulfur-rich polymers have gained a great deal of attention as the next-generation active materials in lithium-sulfur(Li-S)batteries due to their low cost,environmental compatibility,naturally sulfur uniform dispersion...Sulfur-rich polymers have gained a great deal of attention as the next-generation active materials in lithium-sulfur(Li-S)batteries due to their low cost,environmental compatibility,naturally sulfur uniform dispersion,and distinctive structure covalently bonding with sulfur atoms.However,the poor electrical conductivity and undesirable additional shuttle effect still hinder the commercial application of sulfur-rich polymers.Herein,we report a flexible semi-immobilization strategy to prepare allylterminated hyperbranched poly(ethyleneimine)-functionalized reduced graphene oxide(A-PEI-EGO)as sulfur-rich copolymer backbone.The semi-immobilization strategy can effectively reconcile the demand for polymer skeleton and conductive substrates through forming quaternary ammonium groups and reducing oxygen-containing functional groups,resulting in enhanced skeleton adsorption capacity and substrate electronic conductivity,respectively.Furthermore,the stable covalent bonding connection based on polymer molecules(A-PEI)not only completely prevents the additional shuttle effect of lithiation organic molecules and even sulfur-rich oligomers,but provides more inverse vulcanization active sites.As a result,the as-prepared A-PEI-EGO-S cathodes display an initial discharge capacity of1338 m A h g^(-1)at a rate of 0.1 C and an outstanding cycling stability of 0.046%capacity decay per cycle over 600 cycles.Even under 6.2 mg cm^(-2)S-loaded and sparing electrolyte of 6μL mg^(-1),the A-PEI-EGO-S cathode can also achieve a superior cycling performance of 98%capacity retention after 60 cycles,confirming its application potential.展开更多
The capacitance performances of poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate）（PEDOT-PSS） supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 ...The capacitance performances of poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate）（PEDOT-PSS） supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 F/g and display excellent rate capability at the scan rate as high as 5000 m V/s in the cyclic voltammogram measurements, accompanied by good cycle stability. On the basis of the measurements of the microscale morphologies, specific areas and electrical conductivities, the mechanisms for the improvement of the electrochemical properties are discussed and ascribed to the novel porous microstructures of the hydrogels and the synergetic effect of the rigid PEDOT and soft PSS components. Furthermore, polyaniline（PAn） is compounded with the PEDOT-PSS hydrogels through an interfacial polymerization process, endowing the hydrogel materials with a higher specific capacitance of 160 F/g at the scan rate of 5000 m V/s. The significance of this work lies in the demonstration of a novel method to solve the problems of conducting polymers in electrochemical applications.展开更多
SiOx is attractive as an anode material for lithium-ion batteries(LIBs)due to its high capacity,low cost,and relatively higher cyclic stability than Si anode.However,the intrinsic low electronic conductivity,low initi...SiOx is attractive as an anode material for lithium-ion batteries(LIBs)due to its high capacity,low cost,and relatively higher cyclic stability than Si anode.However,the intrinsic low electronic conductivity,low initial coulombic efficiency(ICE),and volume expansion during cycles hinder its applications.In this review,we summarize advances in high performance SiOx anodes,mainly from two aspects:active material and binders.The future perspective is investigated at the end of this review.Our review provides strategical guidance for developing high performance SiOx anodes.展开更多
In this work,azobenzene mesogen-containing tin thiolates have been synthesized,which possess ordered lamellar structures persistent to higher temperature and serve as liquid crystalline precursors.Based on the preorga...In this work,azobenzene mesogen-containing tin thiolates have been synthesized,which possess ordered lamellar structures persistent to higher temperature and serve as liquid crystalline precursors.Based on the preorganized tin thiolate precursors,Sn S nanocrystals encapsulated with in-situ N-doped carbon layer have been achieved through a simple solventless pyrolysis process with the azobenzene mesogenic thiolate precursor served as Sn,S,N,and C sources simultaneously.Thus prepared nanocomposite materials as anode of lithium ion batteries present a large specific capacity of 604.6 m Ah·g^（-1）at a current density of 100 m A·g^（-1）,keeping a high capacity retention up to 96% after 80 cycles,and display high rate capability due to the synergistic effect of well-dispersed Sn S nanocrystals and N-doped carbon layer.Such encouraging results shed a light on the controlled preparation of advanced nanocomposites based on liquid crystalline metallomesogen precursors and may boost their novel intriguing applications.展开更多
Pore structure engineering has been acknowledged as suitable approach to creating active sites and en-hancing ion transport capabilities of hard carbon anodes.However,conventional porous carbon materials exhibit high ...Pore structure engineering has been acknowledged as suitable approach to creating active sites and en-hancing ion transport capabilities of hard carbon anodes.However,conventional porous carbon materials exhibit high BET and surface defects.Additionally,the sodium storage mechanism predominantly occurs in the slope region.This contradicts practical application requirements because the capacity of the plateau region is crucial for determining the actual capacity of batteries.In our work,we prepared a novel“core-shell”carbon framework(CNA1200).Introducingclosedporesand carboxylgroupsinto coal-basedcarbon materials to enhance its sodium storage performance.The closed pore structure dominates in the“core”structure,which is attributed to the timely removal of sodium hydroxide(NaOH)to prevent further for-mation of active carbon structure.The presence of closed pores is beneficial for increasing sodium ion storage in the low-voltage plateau region.And the“shell”structure originates from coal tar pitch,it not only uniformly connects hard carbon particles together to improve cycling stability,but is also rich in carboxyl groups to enhance the reversible sodium storage performance in slope region.CNA1200 has ex-cellent electrochemical performance,it exhibits a specific capacity of 335.2 mAh g^(−1)at a current density of 20 mA g^(−1)with ICE=51.53%.In addition,CNA1200 has outstanding cycling stability with a capac-ity retention of 91.8%even when cycling over 200 times.When CNA1200 is used as anode paired with Na_(3)V_(2)(PO_(4))_(3)cathode,it demonstrates a capacity of 109.54 mAh g^(−1)at 0.1 C and capacity retention of 94.64%at 0.5 C.This work provides valuable methods for regulating the structure of sodium-ion battery(SIBs)anode and enhances the potential for commercialization.展开更多
This study exhibits a design of the discharge product film of a bulk AZ63-Ce-La-Ca(AZ63X)anode for Mg-air battery.An ideal discharge product film for Mg anode is that it could inhibit the anodic hydrogen evolution but...This study exhibits a design of the discharge product film of a bulk AZ63-Ce-La-Ca(AZ63X)anode for Mg-air battery.An ideal discharge product film for Mg anode is that it could inhibit the anodic hydrogen evolution but does not hinder the transfer of the electrons at the interface.Fortunately,the addition of Ce,La,and Ca into AZ63 alloy achieves this goal.The Mg-air battery with AZ63X anode in 3.5%Na Cl has an ultrahigh anodic efficiency of 85.7±1.7%and energy-density of 2431±53 mWh g^(-1)with the unique discharge product film,surpassing the values of most reported Mg-air batteries.Furthermore,the alloying elements reduce the anode delamination effect significantly by transforming the block Mg_(17)Al_(12)phase into the connected Mg_(17)Al_(12)structure and fine rod Al_(2)RE and Al_(2)Ca.展开更多
Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode draws significant attention in the field of energy storage due to its unique voltage plateau.To further enhance the long-term electrochemical stability of LNMO,the LNMO cath...Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode draws significant attention in the field of energy storage due to its unique voltage plateau.To further enhance the long-term electrochemical stability of LNMO,the LNMO cathode covered with an ultrathin ZrO_(2)layer was prepared through atomic layer deposition(ALD).It is found that the LNMO cathode deposited with 20 layers of ZrO_(2)(LNMOZ20)exhibits the best electrochemical performance,achieving a high discharge capacity of 117.1 mA·h/g,with a capacity retention of 87.4%after 600 cycles at a current density of 1C.Furthermore,even at higher current densities of 5C and 10C,the LNMOZ20 electrode still demonstrates excellent stability with discharge capacities reaching 111.7 and 103.6 mA·h/g,and capacity retentions maintaining at 81.0%and 101.4%after 2000 cycles,respectively.This study highlights that the incorporation of an ultrathin ZrO_(2)layer by ALD is an effective strategy for enhancing the long-term cycling stability of LNMO cathodes.展开更多
Earth-abundant,layered birnessite is promising cathode for electrochemical capacitors due to the presence of confined nanofluids in interlayers for rapid ion storage.Previous work has demonstrated the capacitive co-in...Earth-abundant,layered birnessite is promising cathode for electrochemical capacitors due to the presence of confined nanofluids in interlayers for rapid ion storage.Previous work has demonstrated the capacitive co-intercalation of water and K+ions into birnessite in aqueous electrolytes,but in-depth quantitative investigations of the interactions between confined water and an external organic electrolyte are still lacking.In this work,we reveal the intercalation pseudocapacitance of hydrated birnessite(Na_(0.4)MnO_(2)·0.53H_(2)O)in sodium-based organic electrolytes via operando electrochemical quartz crystal microbalance(EQCM),and ex situ X-ray diffraction and Raman spectroscopy.The Na+ions are completely desolvated at the Na_(0.4)MnO_(2)·0.53H_(2)O-organic electrolyte interfaces and intercalate into the interlayers,while the confined water does not co-extract.The net Na+intercalation is a pseudocapacitive behavior without phase changes,displaying a high capacitive contribution of 85.6%at 1.0 m V/s.Additionally,EQCM results indicate the contributions of cation-dominated electric double layer(EDL)adsorption to the total charge storage.By replacing different solvents and anions in sodium-based organic electrolytes,we verify that Na+pseudocapacitive intercalation dominates the charge storage properties.展开更多
Solid-state lighting is now developing toward high-power and super-brightness,but is largely limited by the lack of highly robust and efficient color conversion materials that can be survived from high-power or high-p...Solid-state lighting is now developing toward high-power and super-brightness,but is largely limited by the lack of highly robust and efficient color conversion materials that can be survived from high-power or high-power density excitation,typically the red-emitting ones.In this work,we fabricated highly effi-cient and pore-free Sr_(0.5)Ca_(0.5)AlSiN_(3)∶Eu^(2+)(SCASN)red-emitting ceramics by spark plasma sintering of fine phosphor powders.These fine phosphor powders were prepared by treating the commercial phosphors with high-energy ball-milling,centrifugation and acid washing,leading to a particle size of 2.55μm and an internal quantum efficiency as high as 74.0%under 450 nm excitation.The phosphor powders can be densified into SCASN ceramics without using sintering additives at a temperature as low as 1475℃,and the ceramics show an internal quantum efficiency of 75.3%,which is 50%higher than those ceram-ics fabricated with untreated commercial powders.When excited by a high-power blue LED at a current density of 4 A/mm^(2),the SCASN ceramics have a maximum luminous flux of 660 lm(i.e.,26 Mcd/m^(2)).The phosphor ceramics can also withstand a high laser power density of 15.7 W/mm^(2),and exhibit an output luminance of 188 Mcd/m^(2).This work provides a general method to prepare fine phosphor powders that enable to fabricate high efficiency phosphor ceramics used in high-power solid-state lighting.展开更多
Persistent Luminescence(PersL)materials,which use traps to store energy and emit photons over a long period,have found important applications in the fields of optical information storage,security labeling,and biologic...Persistent Luminescence(PersL)materials,which use traps to store energy and emit photons over a long period,have found important applications in the fields of optical information storage,security labeling,and biological imaging.The trap depth is a crucial factor determining the performance of these materials;however,achieving the desired trap depth with high precision remains a great challenge.Here,we provide double perovskite phosphors(Cs_(2)SnCl_(6)-Cs_(2)ZrCl_(6)-Cs_(2)HfCl_(6)series)with highly compatible crystal structures,enabling continuous and precise tuning of trap depth over an ultra-wide range of 0.11-1.25 eV.By incorporating W4+as the luminescent centers,these phosphors exhibit outstanding near-infrared(NIR)PersL performance at approximately 900 nm and a lasting emission duration exceeding 10 h.The underlying mechanism of PersL is elucidated,and the wide-range tunability of trap depth is attributed to the universal applicability of band-gap engineering in the entire material system.Furthermore,we demonstrate the practical application of these materials by designing a flexible detector plate for X-ray imaging.The detector plate exhibits a storage time of more than 1 week,a detection limit of 0.83μGyair·s^(-1)in the near-infrared region,and real-time and delay-time imaging resolutions of 14.2 lp·mm^(-1)and 2.5 lp·mm^(-1),respectively.These attributes demonstrate strong potential for X-ray luminescence extension imaging.展开更多
The energy density of thin-film lithium batteries(TFLBs)is predominantly determined by the average voltage and specific capacity,however,the mechanism of regulating the voltage plateaus of the film electrodes is not w...The energy density of thin-film lithium batteries(TFLBs)is predominantly determined by the average voltage and specific capacity,however,the mechanism of regulating the voltage plateaus of the film electrodes is not well understood.In this study,three boride films(Co–B,Fe–B,and Co–Fe–B alloys)with different thick-nesses were fabricated to enhance the specific capacity and voltage stability of TFLBs.By analyzing the cycling performance,redox peak evolution,and capacitive contribution,the thickness-dependent lithiation behavior of the thin/thick films was elucidated.Theoretical simulations and electrochemical analysis were conducted to investigate how the lithiation behaviors affected the voltage profiles of the film electrodes.In addition,the various-thickness CoB films were compared in all-solid-state TFLBs,demonstrating the universality and practicability of this simple regulation strategy to develop high-performance energy storage devices.展开更多
Balancing high display performance with energy efficiency is crucial for global sustainability.Lowering operating frequencies—such as enabling 1 Hz operation in fringe-field switching(FFS)liquid crystal displays—red...Balancing high display performance with energy efficiency is crucial for global sustainability.Lowering operating frequencies—such as enabling 1 Hz operation in fringe-field switching(FFS)liquid crystal displays—reduces power consumption but is hindered by image flicker.While negative dielectric anisotropy liquid crystals(nLCs)mitigate flicker,their high driving voltages and production costs limit adoption.Positive dielectric anisotropy liquid crystals(pLCs)offer lower operating voltages,faster response times,and broader applicability,making them a more viable alternative.This study introduces a novel approach to minimizing flexoelectric effects in pLCs by investigating how single components influence flexoelectric behavior in mixtures through an effective experimental methodology.Two innovative measurement techniques—(1)flexoelectric coefficient difference analysis and(2)displacement-current measurement(DCM)—are presented,marking the first application of DCM for verifying flexoelectric effects.The proposed system eliminates uncertainties associated with previous methods,providing a reliable framework for selecting liquid crystal components with minimal flexoelectric effects while preserving key electro-optic properties.Given pLCs'higher reliability,lower production costs,and broader material selection,these advancements hold significant potential for low-power displays.We believe this work enhances flexoelectric analysis in nematic liquid crystals and contributes to sustainable innovation in the display industry,aligning with global energy-saving goals.展开更多
基金Project supported by the National Key Research and Development Program(2022YFE0108800)。
文摘Eu^(2+)-doped phosphors show broadband absorption,tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions,allowing them to be used in solid-state lighting.To expand their applications in other fields such as detection and sensing technologies,the Eu^(2+)emission needs to be tuned into the near-infrared region,but it is a big challenge to obtain Eu^(2+)near-infrared region emitters due to the absence of host compounds with extremely large crystal-field splitting.In this work,we chose M_(4)Li(BN_(2))_(3)(M=Ca,Sr,Ba)as a host and realize the near-infrared region emission of Eu^(2+)in it.Among these phosphors,Ba4Li(BN_(2))_(3):Eu^(2+)exhibits the longest emission of 880 nm and the largest full-width at half maximum of 276 nm under 450 nm excitation,while Ca_(4)Li(BN_(2))_(3):Eu^(2+)and Sr_(4)Li(BN_(2))_(3):Eu^(2+)emit at740 and 680 nm,respectively.We observe an interesting phenomenon that the energy shift of emission is linearly related to the radius difference between the alkaline earth cation and the activator Eu^(2+)in this system.
基金supported by the National Natural Science Foundation of China(Nos.51831007,52101135)the Shenzhen Science and Technology Program,China(No.SGDX20210823104002016)the Guangdong Basic and Applied Basic Research Foundation,China(Nos.2021B1515120071,JCYJ20220531095217039)。
文摘Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The Co−30Ni−10Al−3V−6Ti−2Ta alloy,designed based onγʹphase dissolution temperature and phase fraction,was synthesized via arc melting and heat treatment.Phase transition temperatures,microstructure evolution,and hightemperature mechanical properties were characterized by differential scanning calorimetry,scanning electron microscopy,dual-beam TEM,and compression tests.Results show that the alloy has low density(8.15 g/cm^(3))and highγʹdissolution temperature(1234℃),along with unique yield strength retention from room temperature to 650℃.The yield strength anomaly(YSA)is attributed to high stacking fault energy and activation of the Kear−Wilsdorf locking mechanism,contributing to superior high-temperature stability of the alloy.The yield strength of this alloy outperforms other lowdensity Co-based superalloys in the temperature range of 23−650℃.
基金supported by the National Natural ScienceFoundation of China(Nos.52371007 and 51831007).
文摘Enhancing the oxidation resistance of Co-based superalloys by adding a high content of Cr,while simultaneously ensuring the stability of theγ/γ′phases,presents a significant challenge.This study evaluated the alloying potential of Co–30Ni–10Al–5V–4Ta using the CALPHAD method,revealing promising characteristics.The developed Co–30Ni–10Al–5V–4Ta–12Cr alloy characterized by high Cr content andγ/γ′two-phase structure,demonstrating highγ′solvus temperature of 1139℃,low density of 8.48 g/cm^(3),minimalγ/γ′lattice misfit of +0.28%,high compressive yield strength of 651 MPa at 800℃,and excellent oxidation resistance with a weight gain of 6.5 mg/cm^(3)after 200 h at 1000℃.Examination of the oxidation behavior at 1000℃ revealed an oxide layer consisting of a porous outer CoO,NiO,and V_(3)O_(4)(CNV)oxide and a denser inner mixed oxide layer comprising CoO,NiO,and V_(3)O_(4)(CNV)oxide,Al_(2)O_(3),Cr_(2)O_(3),CoO,and NiO(CNAC)oxide,and TaO_(2),CoO,and NiO(CNT)oxide.
基金the National Key R&D program of China(Grant No.2022YFB3705300the National Natural Science Foundation of China(Grant Nos.U23A20613 and 52171123)for financial support.
文摘Austenitic steel is a prime candidate for structural applications in extreme environments such as nuclear fusion reactors due to its favorable cryogenic mechanical properties.A heterogeneous microstructure was developed via cold rolling followed by short-term annealing,resulting in partially recrystallized regions interspersed with non-recrystallized regions in an austenitic stainless steel.A series of tensile tests conducted at both room temperature and 77 K,combined with digital image correlation,nanoindentation,electron backscatter diffraction,and transmission electron microscopy,were employed to investigate the strain partitioning and deformation mechanisms of the microstructure.The results reveal that at 77 K,the yield strength reaches 1330 MPa and the total elongation increases to 51.49%,surpassing the performance observed at the room temperature.The cryogenic environment reduces the stacking fault energy,thereby promoting the formation of stacking faults and deformation twins in the recrystallized regions.Concurrently,the non-recrystallized regions exhibit pronounced strain-induced martensitic transformation that enhances ductility through the transformation-induced plasticity effect.These synergistic interactions between the distinct microstructural regions underpin the remarkable strength-ductility balance of the steel under cryogenic conditions.
基金supported by the National Natural Science Foundation of China(Nos.U23A20610,52164017,52064011,52274331,and 521043348)the Guizhou Provincial Basic Research Program(Natural Science)(Nos.ZK[2021]258 and ZK[2023]Zhongdian 020)+6 种基金the Guizhou Provincial Program on Commercialization of Scientific and Technological Achievements(No.[2021]086)the Natural Science Research Project of Guizhou Provincial Department of Education(No.[2022]041)the Key Research Projects in Higher Education Institutions of Henan Province(No.24B450003)the Zhengzhou Railway Vocational and Technical College School Scientific Research Project(No.2024KY015)the Guizhou Province Dual-Carbon and New Energy Technology Innovation and Development Research Institute Open Project(No.DCRE-2023-01)the Guizhou Provincial Science and Technology Projects(No.GCC[2023]017)supported by the State Key Laboratory of Advanced Metallurgy(No.K23-04)。
文摘In the casting process of 1060 industrial pure aluminum,the inclusions in the aluminum melt significantly affect the product quality.In this study,the influence of refining temperature and the composition of salt fluxes on the purification effect and mechanical properties of aluminum melt was investigated.The results indicate that lower refining temperatures and modified salt fluxes can effectively enhance the cleanliness of the aluminum melt.As the refining temperature increases,the large inclusions gradually increase.The addition of16wt.%Na_(3)AlF_(6) can dissolve and break up Al_2O_(3) inclusions,facilitating the separation of the aluminum melt and aluminum slag.The addition of 16wt.%Na3AlF6 and 2wt.%CaCO_(3) to the basic salt fluxes enables gas refinement,thereby further improving the cleanliness of the aluminum melt.Under the refining condition of 37wt.%NaCl-47wt.%KCl--16wt.%Na3AIF3-2wt.%CaCO_(3) at 740℃,better cleanliness and mechanical properties were obtained.The cleanliness and yield strength are approximately 99.99928%and 71.46 MPa,respectively.This work can offer valuable reference and theoretical insights for future research.
基金financial support from the National Natural Science Foundation of China(Grant Nos.51871188 and 51931006)the Fundamental Research Funds for the Central Universities of China(Xiamen University:Nos.20720200068,20720190007 and 20720220074)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2021A1515010139)Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(HRTP-[2022]-22)the“Double-First Class”Foundation of Materials Intelligent Manufacturing Discipline of Xiamen University。
文摘The commercial viability of lithium-sulfur batteries is still challenged by the notorious lithium polysulfides(Li PSs)shuttle effect on the sulfur cathode and uncontrollable Li dendrites growth on the Li anode.Herein,a bi-service host with Co-Fe binary-metal selenide quantum dots embedded in three-dimensional inverse opal structured nitrogen-doped carbon skeleton(3DIO FCSe-QDs@NC)is elaborately designed for both sulfur cathode and Li metal anode.The highly dispersed FCSe-QDs with superb adsorptive-catalytic properties can effectively immobilize the soluble Li PSs and improve diffusion-conversion kinetics to mitigate the polysulfide-shutting behaviors.Simultaneously,the 3D-ordered porous networks integrated with abundant lithophilic sites can accomplish uniform Li deposition and homogeneous Li-ion flux for suppressing the growth of dendrites.Taking advantage of these merits,the assembled Li-S full batteries with 3DIO FCSe-QDs@NC host exhibit excellent rate performance and stable cycling ability(a low decay rate of 0.014%over 2,000 cycles at 2C).Remarkably,a promising areal capacity of 8.41 mAh cm^(-2)can be achieved at the sulfur loading up to 8.50 mg cm^(-2)with an ultra-low electrolyte/sulfur ratio of 4.1μL mg^(-1).This work paves the bi-serve host design from systematic experimental and theoretical analysis,which provides a viable avenue to solve the challenges of both sulfur and Li electrodes for practical Li-S full batteries.
基金financially supported by the National Key Research and Development Program of China (2017YFA0208200)the National Natural Science Foundation of China (52102100,22022505 and 21872069)+4 种基金the Natural Science Foundation of Jiangsu Province (BK20181469)Guangdong Basic and Applied Basic Research Foundation (2020A1515110035)the Fundamental Research Funds for the Central Universities (0205-14380266,0205-14380272)the Scientific and Technological Innovation Special Fund for Carbon Peak and Carbon Neutrality of Jiangsu Province (BK20220008)the 2021 Suzhou Gusu Leading Talents of Science and Technology Innovation and Entrepreneurship in Wujiang District。
文摘To solve the environmental pollution and low yield during the sythesis of zeolitic imidazolate frameworks(ZIFs)and their derived materials,a KOH-assisted aqueous strategy is proposed to synthesize cobalt zeolitic imidazolate framework(ZIF-67)polyhedrons,which are used as precursors to prepare cobalt selenide/carbon composites with different crystal phases(Co_(0.85)Se,CoSe_2).When evaluated as anode material for lithium ion batteries,Co_(0.85)Se/C composites deliver a reversible capacity of 758.7 m A·h·g^(-1)with a capacity retention rate of 90.5%at 1.0 A·g^(-1)after 500 cycles,and the superior rate capability is 620 m A·h·g^(-1)at 2.0 A·g^(-1).The addition of KOH accelerates the production of ZIF-67 crystals by boosting deprotonation of dimethylimidazole,resulting in rapid growth and structures transition from two-dimensional to three-dimensional of ZIF-67 in aqueous solution,which greatly promotes the application of MOFs in the field of energy storage and conversion.
基金supported by CITIC Dameng Mining Industries Limited-Guangxi University Joint Research Institute of manganese resources utilization and advanced materials technology,Guangxi University-CITIC Dameng Mining Industries Limited Joint base of postgraduate cultivation,National Natural Science Foundation of China(No.11364003)Guangxi Innovation Driven Development Project(Nos.AA17204100,AA18118052)the Natural Science Foundation of Guangxi Province(No.2018GXNSFAA138186)。
文摘The organic carbon source coating LiFe_(x)Mn_(1-x)PO_(4)suffers from the problem of non-uniform carbon cladding.Too thick carbon cladding layer instead hinders the de-embedding of lithium ions.In this paper,we choose cornstalk as the carbon source,then LiFe_(0.5)Mn_(0.5)PO_(4)@cornstalk-C(LFMP@C-C)with 3D anchoring structure is prepared by the solvothermal method.The results show that the LFMP with cornstalk as the carbon source has better performance compared to the sucrose-coated LFMP material(LFMP@C).The discharge capacity of LFMP@C-C is 116 mAh/g for the first cycle at 1 C and the capacity retention rate is 94.0%after 500 cycles,and the discharge capacity of LFMP@C-C is more than 17.17%higher than that of LFMP@C.
基金the support from National Outstanding Youth Science Fund (52222314)the CNPC Innovation Found (2021DQ02-1001)+2 种基金the Liao Ning Revitalization Talents Program (XLYC1907144)the Xinghai Talent Cultivation Plan (X20200303)the Fundamental Research Funds for the Central Universities (DUT22JC02,DUT22LAB605)。
文摘Sulfur-rich polymers have gained a great deal of attention as the next-generation active materials in lithium-sulfur(Li-S)batteries due to their low cost,environmental compatibility,naturally sulfur uniform dispersion,and distinctive structure covalently bonding with sulfur atoms.However,the poor electrical conductivity and undesirable additional shuttle effect still hinder the commercial application of sulfur-rich polymers.Herein,we report a flexible semi-immobilization strategy to prepare allylterminated hyperbranched poly(ethyleneimine)-functionalized reduced graphene oxide(A-PEI-EGO)as sulfur-rich copolymer backbone.The semi-immobilization strategy can effectively reconcile the demand for polymer skeleton and conductive substrates through forming quaternary ammonium groups and reducing oxygen-containing functional groups,resulting in enhanced skeleton adsorption capacity and substrate electronic conductivity,respectively.Furthermore,the stable covalent bonding connection based on polymer molecules(A-PEI)not only completely prevents the additional shuttle effect of lithiation organic molecules and even sulfur-rich oligomers,but provides more inverse vulcanization active sites.As a result,the as-prepared A-PEI-EGO-S cathodes display an initial discharge capacity of1338 m A h g^(-1)at a rate of 0.1 C and an outstanding cycling stability of 0.046%capacity decay per cycle over 600 cycles.Even under 6.2 mg cm^(-2)S-loaded and sparing electrolyte of 6μL mg^(-1),the A-PEI-EGO-S cathode can also achieve a superior cycling performance of 98%capacity retention after 60 cycles,confirming its application potential.
基金financially supported by the National Natural Science Foundation of China(Nos.21174059 and 21374046)China Postdoctoral Science Foundation(No.2013M530249)+1 种基金Program for Changjiang Scholars and Innovative Research Teams in Universities,Open Project of State Key Laboratory of Superamolecular Structure and Materials(No.SKLSSM201416)the Testing Foundation of Nanjing University
文摘The capacitance performances of poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate）（PEDOT-PSS） supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 F/g and display excellent rate capability at the scan rate as high as 5000 m V/s in the cyclic voltammogram measurements, accompanied by good cycle stability. On the basis of the measurements of the microscale morphologies, specific areas and electrical conductivities, the mechanisms for the improvement of the electrochemical properties are discussed and ascribed to the novel porous microstructures of the hydrogels and the synergetic effect of the rigid PEDOT and soft PSS components. Furthermore, polyaniline（PAn） is compounded with the PEDOT-PSS hydrogels through an interfacial polymerization process, endowing the hydrogel materials with a higher specific capacitance of 160 F/g at the scan rate of 5000 m V/s. The significance of this work lies in the demonstration of a novel method to solve the problems of conducting polymers in electrochemical applications.
基金National Natural Science Foundation of China(No.21905194)Natural Science Foundation of the Jiangsu Higher Education Institution of China(No.23KJB150032).
文摘SiOx is attractive as an anode material for lithium-ion batteries(LIBs)due to its high capacity,low cost,and relatively higher cyclic stability than Si anode.However,the intrinsic low electronic conductivity,low initial coulombic efficiency(ICE),and volume expansion during cycles hinder its applications.In this review,we summarize advances in high performance SiOx anodes,mainly from two aspects:active material and binders.The future perspective is investigated at the end of this review.Our review provides strategical guidance for developing high performance SiOx anodes.
基金Project supported by the National Natural Science Foundation of China(Grant No.21574062)the Huaian High-Technology Research Institute of Nanjing University,China(Grant No.2011Q1)
文摘In this work,azobenzene mesogen-containing tin thiolates have been synthesized,which possess ordered lamellar structures persistent to higher temperature and serve as liquid crystalline precursors.Based on the preorganized tin thiolate precursors,Sn S nanocrystals encapsulated with in-situ N-doped carbon layer have been achieved through a simple solventless pyrolysis process with the azobenzene mesogenic thiolate precursor served as Sn,S,N,and C sources simultaneously.Thus prepared nanocomposite materials as anode of lithium ion batteries present a large specific capacity of 604.6 m Ah·g^（-1）at a current density of 100 m A·g^（-1）,keeping a high capacity retention up to 96% after 80 cycles,and display high rate capability due to the synergistic effect of well-dispersed Sn S nanocrystals and N-doped carbon layer.Such encouraging results shed a light on the controlled preparation of advanced nanocomposites based on liquid crystalline metallomesogen precursors and may boost their novel intriguing applications.
基金the National Natural Science Foundation of China(No.21978164,22078189 and 22105120)the Outstanding Youth Science Fund of Shaanxi Province(No.2021JC-046)and the Special Support Program for high level talents of Shaanxi Province+3 种基金the Innovation Support Program of Shaanxi Province(2021JZY-001)the Key Research and Development Program of Shaanxi Province(No.2020GY-243)the Special Research Fund of Education Department of Shaanxi(No.20JK0535)the National High-end Foreign Expert Project(No.GDW20186100428).
文摘Pore structure engineering has been acknowledged as suitable approach to creating active sites and en-hancing ion transport capabilities of hard carbon anodes.However,conventional porous carbon materials exhibit high BET and surface defects.Additionally,the sodium storage mechanism predominantly occurs in the slope region.This contradicts practical application requirements because the capacity of the plateau region is crucial for determining the actual capacity of batteries.In our work,we prepared a novel“core-shell”carbon framework(CNA1200).Introducingclosedporesand carboxylgroupsinto coal-basedcarbon materials to enhance its sodium storage performance.The closed pore structure dominates in the“core”structure,which is attributed to the timely removal of sodium hydroxide(NaOH)to prevent further for-mation of active carbon structure.The presence of closed pores is beneficial for increasing sodium ion storage in the low-voltage plateau region.And the“shell”structure originates from coal tar pitch,it not only uniformly connects hard carbon particles together to improve cycling stability,but is also rich in carboxyl groups to enhance the reversible sodium storage performance in slope region.CNA1200 has ex-cellent electrochemical performance,it exhibits a specific capacity of 335.2 mAh g^(−1)at a current density of 20 mA g^(−1)with ICE=51.53%.In addition,CNA1200 has outstanding cycling stability with a capac-ity retention of 91.8%even when cycling over 200 times.When CNA1200 is used as anode paired with Na_(3)V_(2)(PO_(4))_(3)cathode,it demonstrates a capacity of 109.54 mAh g^(−1)at 0.1 C and capacity retention of 94.64%at 0.5 C.This work provides valuable methods for regulating the structure of sodium-ion battery(SIBs)anode and enhances the potential for commercialization.
基金supported by the National Natural Science Foundation of China(52471095)National Key Research and Development Program of China(Grant No.2023YFC2811404)Natural Science Foundation of Xiamen,China(No.3502Z20227015)。
文摘This study exhibits a design of the discharge product film of a bulk AZ63-Ce-La-Ca(AZ63X)anode for Mg-air battery.An ideal discharge product film for Mg anode is that it could inhibit the anodic hydrogen evolution but does not hinder the transfer of the electrons at the interface.Fortunately,the addition of Ce,La,and Ca into AZ63 alloy achieves this goal.The Mg-air battery with AZ63X anode in 3.5%Na Cl has an ultrahigh anodic efficiency of 85.7±1.7%and energy-density of 2431±53 mWh g^(-1)with the unique discharge product film,surpassing the values of most reported Mg-air batteries.Furthermore,the alloying elements reduce the anode delamination effect significantly by transforming the block Mg_(17)Al_(12)phase into the connected Mg_(17)Al_(12)structure and fine rod Al_(2)RE and Al_(2)Ca.
基金supported by the National Natural Science Foundation of China(Nos.51931006,U22A20118).
文摘Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode draws significant attention in the field of energy storage due to its unique voltage plateau.To further enhance the long-term electrochemical stability of LNMO,the LNMO cathode covered with an ultrathin ZrO_(2)layer was prepared through atomic layer deposition(ALD).It is found that the LNMO cathode deposited with 20 layers of ZrO_(2)(LNMOZ20)exhibits the best electrochemical performance,achieving a high discharge capacity of 117.1 mA·h/g,with a capacity retention of 87.4%after 600 cycles at a current density of 1C.Furthermore,even at higher current densities of 5C and 10C,the LNMOZ20 electrode still demonstrates excellent stability with discharge capacities reaching 111.7 and 103.6 mA·h/g,and capacity retentions maintaining at 81.0%and 101.4%after 2000 cycles,respectively.This study highlights that the incorporation of an ultrathin ZrO_(2)layer by ALD is an effective strategy for enhancing the long-term cycling stability of LNMO cathodes.
基金supported by the National Natural Science Foundation of China(No.22179113)the Guangdong High-Level Innovation Institute Project(No.2021B0909050001)the Fundamental Research Funds for the Central Universities(No.20720230028)。
文摘Earth-abundant,layered birnessite is promising cathode for electrochemical capacitors due to the presence of confined nanofluids in interlayers for rapid ion storage.Previous work has demonstrated the capacitive co-intercalation of water and K+ions into birnessite in aqueous electrolytes,but in-depth quantitative investigations of the interactions between confined water and an external organic electrolyte are still lacking.In this work,we reveal the intercalation pseudocapacitance of hydrated birnessite(Na_(0.4)MnO_(2)·0.53H_(2)O)in sodium-based organic electrolytes via operando electrochemical quartz crystal microbalance(EQCM),and ex situ X-ray diffraction and Raman spectroscopy.The Na+ions are completely desolvated at the Na_(0.4)MnO_(2)·0.53H_(2)O-organic electrolyte interfaces and intercalate into the interlayers,while the confined water does not co-extract.The net Na+intercalation is a pseudocapacitive behavior without phase changes,displaying a high capacitive contribution of 85.6%at 1.0 m V/s.Additionally,EQCM results indicate the contributions of cation-dominated electric double layer(EDL)adsorption to the total charge storage.By replacing different solvents and anions in sodium-based organic electrolytes,we verify that Na+pseudocapacitive intercalation dominates the charge storage properties.
基金supported by the National Key Research and Development Program(MOST,No.2022YFE0108800)the National Natural Science Foundation of China(Nos.52272165,U2005213 and 52172157)the Major Science and Technology Projects of Xiamen Science and Technology Bureau(No.3502Z20231018).
文摘Solid-state lighting is now developing toward high-power and super-brightness,but is largely limited by the lack of highly robust and efficient color conversion materials that can be survived from high-power or high-power density excitation,typically the red-emitting ones.In this work,we fabricated highly effi-cient and pore-free Sr_(0.5)Ca_(0.5)AlSiN_(3)∶Eu^(2+)(SCASN)red-emitting ceramics by spark plasma sintering of fine phosphor powders.These fine phosphor powders were prepared by treating the commercial phosphors with high-energy ball-milling,centrifugation and acid washing,leading to a particle size of 2.55μm and an internal quantum efficiency as high as 74.0%under 450 nm excitation.The phosphor powders can be densified into SCASN ceramics without using sintering additives at a temperature as low as 1475℃,and the ceramics show an internal quantum efficiency of 75.3%,which is 50%higher than those ceram-ics fabricated with untreated commercial powders.When excited by a high-power blue LED at a current density of 4 A/mm^(2),the SCASN ceramics have a maximum luminous flux of 660 lm(i.e.,26 Mcd/m^(2)).The phosphor ceramics can also withstand a high laser power density of 15.7 W/mm^(2),and exhibit an output luminance of 188 Mcd/m^(2).This work provides a general method to prepare fine phosphor powders that enable to fabricate high efficiency phosphor ceramics used in high-power solid-state lighting.
基金supported by the National Natural Science Foundation of China(Nos.52172156,12474412)the Natural Science Foundation of Fujian Province(No.2023J06005)+2 种基金the Natural Science Foundation of Guangdong Province(No.2024A1515011197)the Fundamental Research Funds for the Central Universities(No.20720240057)The DFT calculations in this work was done with the assistance of the Intelligent Computing Center of Tan Kah Kee Innovation Laboratory(IKKEM).
文摘Persistent Luminescence(PersL)materials,which use traps to store energy and emit photons over a long period,have found important applications in the fields of optical information storage,security labeling,and biological imaging.The trap depth is a crucial factor determining the performance of these materials;however,achieving the desired trap depth with high precision remains a great challenge.Here,we provide double perovskite phosphors(Cs_(2)SnCl_(6)-Cs_(2)ZrCl_(6)-Cs_(2)HfCl_(6)series)with highly compatible crystal structures,enabling continuous and precise tuning of trap depth over an ultra-wide range of 0.11-1.25 eV.By incorporating W4+as the luminescent centers,these phosphors exhibit outstanding near-infrared(NIR)PersL performance at approximately 900 nm and a lasting emission duration exceeding 10 h.The underlying mechanism of PersL is elucidated,and the wide-range tunability of trap depth is attributed to the universal applicability of band-gap engineering in the entire material system.Furthermore,we demonstrate the practical application of these materials by designing a flexible detector plate for X-ray imaging.The detector plate exhibits a storage time of more than 1 week,a detection limit of 0.83μGyair·s^(-1)in the near-infrared region,and real-time and delay-time imaging resolutions of 14.2 lp·mm^(-1)and 2.5 lp·mm^(-1),respectively.These attributes demonstrate strong potential for X-ray luminescence extension imaging.
基金supported by National Natural Science Foundation of China(Grant Nos.52101273 and U22A20118)Natural Science Foundation of Fujian Province of China(Grant No.2022J01042)Fundamental Research Funds for Central Universities of China(Grant No.20720242002).
文摘The energy density of thin-film lithium batteries(TFLBs)is predominantly determined by the average voltage and specific capacity,however,the mechanism of regulating the voltage plateaus of the film electrodes is not well understood.In this study,three boride films(Co–B,Fe–B,and Co–Fe–B alloys)with different thick-nesses were fabricated to enhance the specific capacity and voltage stability of TFLBs.By analyzing the cycling performance,redox peak evolution,and capacitive contribution,the thickness-dependent lithiation behavior of the thin/thick films was elucidated.Theoretical simulations and electrochemical analysis were conducted to investigate how the lithiation behaviors affected the voltage profiles of the film electrodes.In addition,the various-thickness CoB films were compared in all-solid-state TFLBs,demonstrating the universality and practicability of this simple regulation strategy to develop high-performance energy storage devices.
基金supported by Basic Science Research Program through the National Research Foundation(NRF)of Korea,funded by the Ministry of Science and ICT(MSIT),Korea[2022R1A2C2091671]by ITECH R&D Program of MOTIE/KEIT(Ministry of Trade,Industry&Energy/Korea Evaluation Institute of Industrial Technology)[20016808].
文摘Balancing high display performance with energy efficiency is crucial for global sustainability.Lowering operating frequencies—such as enabling 1 Hz operation in fringe-field switching(FFS)liquid crystal displays—reduces power consumption but is hindered by image flicker.While negative dielectric anisotropy liquid crystals(nLCs)mitigate flicker,their high driving voltages and production costs limit adoption.Positive dielectric anisotropy liquid crystals(pLCs)offer lower operating voltages,faster response times,and broader applicability,making them a more viable alternative.This study introduces a novel approach to minimizing flexoelectric effects in pLCs by investigating how single components influence flexoelectric behavior in mixtures through an effective experimental methodology.Two innovative measurement techniques—(1)flexoelectric coefficient difference analysis and(2)displacement-current measurement(DCM)—are presented,marking the first application of DCM for verifying flexoelectric effects.The proposed system eliminates uncertainties associated with previous methods,providing a reliable framework for selecting liquid crystal components with minimal flexoelectric effects while preserving key electro-optic properties.Given pLCs'higher reliability,lower production costs,and broader material selection,these advancements hold significant potential for low-power displays.We believe this work enhances flexoelectric analysis in nematic liquid crystals and contributes to sustainable innovation in the display industry,aligning with global energy-saving goals.
