Polycatenane gels have attracted extensive attention due to their high degree of freedom and ***,the syntheses of poly[2]catenane gels reported to date all rely on the polymer as the ***,we prepared poly[2]catenane ge...
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Polycatenane gels have attracted extensive attention due to their high degree of freedom and ***,the syntheses of poly[2]catenane gels reported to date all rely on the polymer as the ***,we prepared poly[2]catenane gels based on entirely sequential assembly of small *** M1 with two unclosed rings was first prepared,which self-assembled to form supramolecular polymers(SPs)via hydrogen bonding andπ-π*** adding small molecule monomers M2 and M3 with aldehyde groups,ring closing of SPs occurred because the amino groups in the SPs reacted with M2 to form imine *** addition,M3,which had twice the number of aldehyde groups as M2,enabled SPs to ring-close,causing the proceeding of crosslinking process at the same *** linear SPs were transformed into poly[2]catenane gel *** to the presence of hydrogen bonds in the poly[2]catenane gel,the gel also possessed stimulus responsiveness and self-healing properties.
Catalytic oxidative desulfurization(ODS) using titanium silicate catalysts has emerged as an efficient technique for the complete removal of organosulfur compounds from automotive fuels. However, the precise control...
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Catalytic oxidative desulfurization(ODS) using titanium silicate catalysts has emerged as an efficient technique for the complete removal of organosulfur compounds from automotive fuels. However, the precise control of highly accessible and stable-framework Ti active sites remains highly challenging. Here we reveal for the first time by using density functional theory calculations that framework hexa-coordinated Ti(TiO6) species of mesoporous titanium silicates are the most active sites for ODS and lead to a lower-energy pathway of ODS. A novel method to achieve highly accessible and homogeneously distributed framework TiO6active single sites at the mesoporous surface has been developed. Such surface framework TiO6species exhibit an exceptional ODS performance. A removal of 920 ppm of benzothiophene is achieved at60°C in 60 min, which is 1.67 times that of the best catalyst reported so far. For bulky molecules such as4,6-dimethyldibenzothiophene(DMDBT), it takes only 3 min to remove 500 ppm of DMDBT at 60°C with our catalyst, which is five times faster than that with the current best catalyst. Such a catalyst can be easily upscaled and could be used for concrete industrial application in the ODS of bulky organosulfur compounds with minimized energy consumption and high reaction efficiency.
In this study, the Al-1-5wt.% X (X=Si, Mn, Mg) alloys were prepared by permanent mold casting, in order to study the relationship between the mechanical properties and thermal conductivity of the alloys. The micro-str...
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Low-cost layered extrusion forming (LEF) technique is often considered to fabricate complex ceramic parts. The 3 mol% yttria-stabilized zirconia (3YSZ) ceramic has been widely used in industrial field because of its e...
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Quantum-confined CsPbBr_(3) perovskites are promising blue emitters for ultra-high-definition displays,but their soft lattice caused by highly ionic nature has a limited ***,we endow CsPbBr_(3) nanoplatelets(NPLs)with...
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Quantum-confined CsPbBr_(3) perovskites are promising blue emitters for ultra-high-definition displays,but their soft lattice caused by highly ionic nature has a limited ***,we endow CsPbBr_(3) nanoplatelets(NPLs)with atomic crystal-like structural rigidity through proper surface engineering,by using strongly bound N-dodecylbenzene sulfonic acid(DBSA).A stable,rigid crystal structure,as well as uniform,orderly-arranged surface of these NPLs is achieved by optimizing intermediate reaction stage,by switching from molecular clusters to mono-octahedra,while interaction with DBSA resulted in formation of a Cs_(x)O monolayer shell capping the NPL *** a result,both structural and optical stability of the CsPbBr3 NPLs is enhanced by strong covalent bonding of DBSA,which inhibits undesired phase transitions and decomposition of the perovskite phase potentially caused by ligand ***,rather small amount of DBSA ligands at the NPL surface results in a short inter-NPL spacing in their closely-packed films,which facilitates efficient charge injection and *** photoluminescence of the produced CsPbBr_(3) NPLs is bright(nearly unity emission quantum yield)and peaks at 457 nm with an extremely narrow bandwidth of 3.7 nm at 80 K,while the bandwidth of the electroluminescence(peaked at 460 nm)also reaches a record-narrow value of 15 nm at room *** value corresponds to the CIE coordinates of(0.141,0.062),which meets Rec.2020 standards for ultra-high-definition displays.
The effects of hydrogen on the mechanical response of pure iron with randomly distributed hydrogen atoms under nanoindentation were systematically investigated by molecular dynamics simulations with the aim to further...
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The effects of hydrogen on the mechanical response of pure iron with randomly distributed hydrogen atoms under nanoindentation were systematically investigated by molecular dynamics simulations with the aim to further understand hydrogen embrittlement mechanism in the *** simulations results revealed that,for the three models with[001],[110]and[111]surface normal,hydrogen reduced the critical load of the pop-in event,promoted the dislocation slipping and reduced the plastic region size and dislocation density around the indenter compared to the hydrogen free ***,the different mechanical responses of the three models with different surface normal were further explained in the perspective of Schmid factor.
Recently,NaNbO_(3)-based ceramics with excellent energy storage performances(ESPs)and fast chargedischarge characteristics have attracted great *** this case,BaTiO_(3) modified 0.85NaNbO_(3)-0.15Bi(Zn_(2/3)Nb_(1/3))O_...
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Recently,NaNbO_(3)-based ceramics with excellent energy storage performances(ESPs)and fast chargedischarge characteristics have attracted great *** this case,BaTiO_(3) modified 0.85NaNbO_(3)-0.15Bi(Zn_(2/3)Nb_(1/3))O_(3)(0.85NN-0.15BZN-yBT)ceramics were designed and successfully fabricated using solid state *** discharge storage density of the ceramics increases from 1.22 J/cm^(3) at y=0-1.84 J/cm^(3) at y=8%,which is 1.5 times higher than pure 0.85NN-0.15BZN *** ceramic reveals excellent temperature stability up to 150℃,good discharge cycling after 10^(5) cycles and high discharge speed of 2.0μs,broadening the scope of NaNbO_(3)-based ceramics for energy storage applications.
Perovskite solar cells(PSCs)offer low costs and high power conversion ***,the lack of long-term stability,primarily stemming from the interfacial defects and the sus-ceptible metal electrodes,hinders their practical *...
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Perovskite solar cells(PSCs)offer low costs and high power conversion ***,the lack of long-term stability,primarily stemming from the interfacial defects and the sus-ceptible metal electrodes,hinders their practical *** the past few years,two-dimensional(2D)materials(e.g.,graphene and its derivatives,transitional metal dichalcogenides,MXenes,and black phosphorus)have been identified as a promising solution to solving these problems because of their dangling bond-free surfaces,layer-dependent electronic band structures,tunable functional groups,and inherent ***,recent progress of 2D material toward efficient and stable PSCs is summarized,including its role as both interface materials and *** discuss their beneficial effects on perovskite growth,energy level alignment,defect passivation,as well as blocking external *** particular,the unique properties of 2D materials to form van der Waals heterojunction at the bottom interface are ***,perspectives on the further development of PSCs using 2D materials are provided,such as designing high-quality van der Waals heterojunction,enhancing the uniformity and coverage of 2D nanosheets,and developing new 2D materials-based electrodes.
M_(3)A_(2)X phases,named 321 phases,are an atypical series of MAX phases featuring in the MA-triangular-prism bilayers,with the A=As/P,exhibiting excellent elastic *** work systematically studies the thermal expansion...
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M_(3)A_(2)X phases,named 321 phases,are an atypical series of MAX phases featuring in the MA-triangular-prism bilayers,with the A=As/P,exhibiting excellent elastic *** work systematically studies the thermal expansion properties of 321 *** found their average linear thermal expansion coefficients(TECs),α_(L)=5-6μK^(–1),are the lowest among the reported values of MAX *** lowest average TEC was found in Nb_(3)As_(2)C(αa=4.46(4)μK^(–1),αc=5.09(4)μK–1,αL=5.09(4)μK–1).The average TEC and anisotropy factor(αc/αa)of Nb_(3)As_(2)C and Nb_(3)P_(2)C were lower than the ones of the corresponding 211 *** best isotropy performance was found in Nb_(3)P_(2)C (αc/αa=1.11).Moreover,our first-principles calculations demonstrate that the weaker chemical bonding between Nb-As/P than Nb-C induces thermal expansion in M_(3)A_(2)X ***,a relatively weaker anharmonic effect in 321 phases than in the 211 phases was revealed by the as-calculated average Grüneisen parameters,which account for the lower TECs in 321 *** low TECs and enhanced thermal isotropy make 321 phases outstanding among MAX phases,which could be sound candidates for varying-temperature structural-functional components.
The use of the internal magnetic field of ferromagnets can effectively promote charge separation and transfer(CST)in photoelectrochemical energy ***,photoelectrochemical materials with a ferromagnetic field are scarce...
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The use of the internal magnetic field of ferromagnets can effectively promote charge separation and transfer(CST)in photoelectrochemical energy ***,photoelectrochemical materials with a ferromagnetic field are scarce,and the internal magnetic field is negligible in nonferromagnetic *** address this issue,we propose a rational method for preparing ferromagnetic TiO_(2)powder using controllable oxygen vacancies in anatase TiO_(2)with co-exposed{001}and{101}***,an ex-cellent saturation magnetisation of 0.0014 emu/g in TiO_(2)is achieved owing to an asymmetric and uneven charge *** with that of nonferromagnetic TiO_(2),the efficiency of photocatalytic hydro-gen generation of ferromagnetic TiO_(2)is improved by 0.64 *** enhancement of photocatalytic hy-drogen generation is due to the different forces exerted on the electrons and holes in the magnetic field,which significantly improve the photogenerated CST efficiency of ferromagnetic TiO_(2).This result high-lights the significant role of the synergistic regulation of the crystal structure and defects in regulating the ferromagnetic characteristics of *** findings of this study provide guidance for leveraging point defects to promote CST for high-efficiency solar-energy conversion systems.
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