High entropy boride ceramics have great potential as structural materials serving in extreme ***,their applications are limited by the difficulty of *** the present study,dense(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2)...
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High entropy boride ceramics have great potential as structural materials serving in extreme ***,their applications are limited by the difficulty of *** the present study,dense(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)ceramics with B_(4)C additions were prepared through pressureless sintering at as low as 1900℃.Calculations based on the CALPHAD approach predict that(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)starts to melt at about 3315℃whilst B_(4)C additions reduce the temperature and broaden the tempera-ture region where solid and liquid *** showed that the introduction of B_(4)C could trigger the densification of(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)at a lower temperature and promote their densification *** relative density of samples with 5 wt%of B_(4)C additions sintered at 1900 and 2000℃was 97.7%and 99.7%,*** the sintering temperature was further increased to 2100℃,the liquid phase was reactively formed,leading to the rapid grain coarsening in samples with B_(4)C *** by well-dispersed B_(4)C grains,the sample with 5 wt%B_(4)C sintered at 2000℃exhibited excellent mechanical properties with the Vickers hardness,flexural strength,and fracture toughness of 21.07±2.09 GPa,547±45 MPa,and 5.24±0.14 MPa m^(1/2),which are comparable or even higher than counterparts sintered under pressure.
Vanadium pentoxide(V_(2)O_(5))with a layered structure is of great interest in the field of electrochromic(EC)due to its abundance of color ***,there are still a series of problems such as slow ion diffusion,poor elec...
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Vanadium pentoxide(V_(2)O_(5))with a layered structure is of great interest in the field of electrochromic(EC)due to its abundance of color ***,there are still a series of problems such as slow ion diffusion,poor electronic conductivity and cyclic stability in the reaction ***,we successfully prepared a stable and fast multi-color electrochromic material V_(2)O_(5)-PEDOT by a simple“one-pot”*** layer space of V_(2)O_(5)could be tuned by 3,4-ethylenedioxythiophene(named V_(2)O_(5)-PEDOT)during the dissolution and recrystallization of vanadium *** expanded layer spacing facilitates rapid ion insertion and *** serves as an internal conductive pillar to improve the overall conductivity of the *** obtained intercrossing structure of the nanobelts shortens the ion diffusion distance and ensures electrolyte *** V_(2)O_(5)-PEDOT exhibits the fast response time(1.1 s for coloration and 3.5 s for bleaching at 422 nm),high optical contrast(ΔT=45%at 422 nm andΔT=35.2%at 1000 nm),great coloration efficiency(CE=97.1 cm2/C),and high cyclic stability(86%preserved after 3000 cycles).The electrochromic devices(ECD)were successfully assembled by using V_(2)O_(5)-PEDOT films as ion storage layers and electrochromic layers,demonstrating remarkable performance.
Sodium-ion batteries are promising candidates for large-scale grid storage systems and other *** foremost advantage derives from superior environmental credentials,enhanced safety as well as lower raw material costs t...
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Sodium-ion batteries are promising candidates for large-scale grid storage systems and other *** foremost advantage derives from superior environmental credentials,enhanced safety as well as lower raw material costs than lithium-ion *** is still challenging to explore desirable anode *** this study,FeSe_(2)@CoSe_(2)/FeSe_(2),with a yolk-shell structure was prepared by ion exchange and *** FeSe_(2)@CoSe_(2)/FeSe_(2)prepared as anode material for sodiumion batteries exhibits excellent rate capability due to the synergistic effect of bimetallic selenides and the interfacial effect of the ***,it delivers high performance(510 mAh g^(-1)at 0.2 A g^(-1)),superior rate capa-bility(90%retention at 5 A g^(-1)),and good long-time cycling stability(78%capacity retention after 1800 cycles at a high current density of 2 A g^(-1)).The optimized sodiumion full cell with FeSe_(2)@CoSe_(2)/FeSe_(2)as the anode and Na 3 V 2(PO 4)3 as the cathode still demonstrates excellent ***,a ca-pacity of 272 mAh g^(-1)(at 1 A g^(-1))within the operating voltage from 1 to 3.8 V can be *** work illustrates the potential of bimetallic selenides with heterostructures for performance enhancement of sodium-ion batteries.
With the rapid development of visual information technology, image sensors are increasingly required to meet complex demands, including higher sensitivity,wider detection band, high-density integration, flexibility, a...
With the rapid development of visual information technology, image sensors are increasingly required to meet complex demands, including higher sensitivity,wider detection band, high-density integration, flexibility, and intelligent functionality [1]. However, conventional image sensors still suffer from inherent limitations, such as poor photoelectric sensitivity, narrow detection bands, and lack of multifunctionality,which significantly limit their capabilities in cutting-edge applications.
Porous ceramics are lightweight materials with diverse pore structures and are widely applied in areas such as thermal insulation, sound absorption, filtration, catalysis, and energy storage. However, excessive shrink...
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Porous ceramics are lightweight materials with diverse pore structures and are widely applied in areas such as thermal insulation, sound absorption, filtration, catalysis, and energy storage. However, excessive shrinkage during the sintering process of porous ceramics leads to cracking and deterioration, posing significant challenges for achieving complex shapes. Despite its importance, the field of low sintering shrinkage porous ceramics has not received sufficient attention. This review systematically discusses the principles and progress in the development of low sintering shrinkage porous ceramics. First, we introduce the characteristics of various preparation methods, including partial sintering, particle-stabilized foaming, gel-casting, foam-gelcasting, and additive manufacturing (AM). We then explain three primary principles of low sintering shrinkage from the perspectives of the volume effect and mass transfer processes. This review focuses on the properties and applications of typical low sintering shrinkage ceramics such as mullite and alumina, particularly their mechanical properties and thermal conductivity as thermal insulation and ceramic cores. Finally, we summarize the current state and present future perspectives on low sintering shrinkage porous ceramics.
The construction of donor-acceptor(D-A)molecular structure is an attractive strategy to enhance the photocatalytic performance of polymeric ***,dibenzothiophene(DBT)-4-carbaldehyde as the precursor is introduced into ...
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The construction of donor-acceptor(D-A)molecular structure is an attractive strategy to enhance the photocatalytic performance of polymeric ***,dibenzothiophene(DBT)-4-carbaldehyde as the precursor is introduced into g-C_(3)N_(4)(TCN)prepared by two-step thermal polymerization to construct an intramolecular D-A type copolymer(TCN-DBT_(x)).DFT calculation and experimental results reveal that DBT plays the role of electron donor unit to modify g-C_(3)N_(4).The incorporation of DBT not only adjusts the band gap to improve reduction ability,but also induces an internal electric field with extendingπ-conjugated system for effective charge *** a result,TCN-DBT_(x)exhibits much better photocatalytic performance with an optimal hydrogen production rate of 3334μmol h^(-1)g^(-1),which is 2.5 times that of *** work provides a protocol for preparing high-performance g-C_(3)N_(4)-based photocatalysts toward various applications.
The(TiNbTaZrHf)C high entropy carbide(HEC)was successfully synthesized by complete commercial transition metal powders,obtained fine sintered bulks without additives by in-situ reaction element synthesis method.(TiNbT...
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The(TiNbTaZrHf)C high entropy carbide(HEC)was successfully synthesized by complete commercial transition metal powders,obtained fine sintered bulks without additives by in-situ reaction element synthesis method.(TiNbTaZrHf)C bulk shows a face centered cubic rock salt structure with homogeneous single-phase FCC structure in composition and *** optimum sintering temperature is about 1900℃at which the best mechanical properties are *** mechanical properties of(TiNbTaZrHf)C ceramic block are better than those of binary transition metal carbides,and it has obvious high entropy *** a small amount of Al as sintering additive,the mechanical properties of(TiNbTaZrHf)C ceramics continue to improve,the bending strength of the samples at each temperature is increased by at least 38%,and the highest is 486 *** elastic modulus and hardness of the sample at 1900℃are also slightly increased by 4%and 14%,*** above conclusions illustrate that the properties of high entropy ceramics are greatly improved by in-situ reaction sintering.
Two isomeric fluorene-based heteroundecenes of bis(thienocyclopenthieno[3,2-b]thieno)fluorene(BT2T-F)and bis(dithieno[3,2-b:2’,3’-d]thiophene)cyclopentafluorene(B3T-F)have been designed and *** side chains of 4-hexy...
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Two isomeric fluorene-based heteroundecenes of bis(thienocyclopenthieno[3,2-b]thieno)fluorene(BT2T-F)and bis(dithieno[3,2-b:2’,3’-d]thiophene)cyclopentafluorene(B3T-F)have been designed and *** side chains of 4-hexylphenyl anchor on the 5th and 8th positions in B3T-F while on the 4th and 9th positions in BT2T-F,in which the former is closer to the center of the fused *** corresponding acceptor-donor-acceptor(A-D-A)type small molecule acceptors(SMAs)of BT2T-FIC and B3T-FIC were prepared by linking BT2T-F and B3T-F as fused ring donor units with the acceptor unit of 2-(5,6-difluoro-3-oxo-2,3-dihydroinden-1-ylidene)malononitrile(IC-2F),respectively.B3T-FIC presents a superior crystallinity with intense face-on π-π stacking in its neat film while BT2T-FIC is more *** blended with PBDB-T-2Cl as a polymer donor,the optimized PBDB-T-2Cl:BT2T-FIC device exhibits an averaged power conversion efficiency(PCE)of 10.56%while only 7.53%in the PBDB-T-2Cl:B3T-FIC *** improved short-circuit current(J_(sc))and fill factor(FF)of the PBDB-T-2Cl:BT2T-FIC device are the main contribution of its higher performance,which is attributed to its more efficient and balanced charge transport and better carrier recombination *** that BT2T-FIC blend and B3T-FIC blend films both take a preferential face-on orientatedπ-πstacking with comparable distances,the suitable SMA domain size obtained in the BT2T-FIC blend could account for its more efficient photovoltaic *** results highlight the importance of side-chain strategy in developing efficient SMAs with huge fused ring cores.
Semiconductor/metal junctions are widely discussed in ***,there is a notable scarcity of systematic studies focusing on photogenerated charge carrier transfer in such ***,CdS/Pt,CdS/Au,and CdS/Ag are synthesized to se...
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Semiconductor/metal junctions are widely discussed in ***,there is a notable scarcity of systematic studies focusing on photogenerated charge carrier transfer in such ***,CdS/Pt,CdS/Au,and CdS/Ag are synthesized to serve as model systems for investigating the charge carrier transfer in semiconductor/metal *** probe force microscopy is employed to visualize the transfer of photogenerated carriers in these *** results show that the electron transfer behavior under illumination is related to the conduction band position of CdS and the Fermi level position of the ***,Schottky junctions hinder the transfer of photogenerated electrons from CdS to Pt and Au,whereas ohmic contacts facilitate the transfer of photogenerated electrons from CdS to *** work provides novel insights into the mechanisms governing the transfer of photogenerated carriers in semiconductor/metal junctions.
Diabetic wounds are a difficult medical *** secretion of matrix metalloproteinase-9(MMP-9)in diabetic wounds further degrades the extracellular matrix and growth factors and causes severe vascular damage,which serious...
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Diabetic wounds are a difficult medical *** secretion of matrix metalloproteinase-9(MMP-9)in diabetic wounds further degrades the extracellular matrix and growth factors and causes severe vascular damage,which seriously hinders diabetic wound *** solve these issues,a double-network porous hydrogel composed of poly(methyl methacrylate-co-acrylamide)(p(MMA-co-AM))and polyvinyl alcohol(PVA)was constructed by the high internal phase emulsion(HIPE)technique for the delivery of potassium sucrose octasulfate(PSO),a drug that can inhibit MMPs,increase angiogenesis and improve *** hydrogel possessed a typical polyHIPE hierarchical microstructure with interconnected porous morphologies,high porosity,high specific surface area,excellent mechanical properties and suitable swelling ***,the p(MMA-co-AM)/PVA@PSO hydrogel showed high drug-loading performance and effective PSO *** addition,both in vitro and in vivo studies showed that the p(MMA-co-AM)/PVA@PSO hydrogel had good biocompatibility and significantly accelerated diabetic wound healing by inhibiting excessive MMP-9 in diabetic wounds,increasing growth factor secretion,improving vascularization,increasing collagen deposition and promoting ***,this study provided a reliable therapeutic strategy for diabetic wound healing,some theoretical basis and new insights for the rational design and preparation of wound hydrogel dressings with high porosity,high drug-loading performance and excellent mechanical properties.
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