The halogenated hydrocarbon amination reaction between the original raw mate-rial N-（（6-bromine-2-methoxylquinoline-3-yl）benzyl）-3-chlorine-N-（naphthalene-1-yl）propionamide and morpholine produces the target mol...The halogenated hydrocarbon amination reaction between the original raw mate-rial N-（（6-bromine-2-methoxylquinoline-3-yl）benzyl）-3-chlorine-N-（naphthalene-1-yl）propionamide and morpholine produces the target molecule N-（（6-bromine-2-methoxylquinoline-3-yl）benzyl）-3-morpholine-N-（naphthalene-1-yl）propionamide （C34H32BrN3O3,Mr=610.54）,and its structure was characterized by 1H NMR,IR,H RMS and X-ray single-crystal diffraction.This crystal is of triclinic system,space group P1 with a=9.315（2）,b=10.3449（12）,c=15.901（3）,α=80.981（14）,β=76.996（17）,γ=74.917（13）°,V=1433.6（5）3,Z=2,Dc=1.414 g/cm3,F（000）= 632,μ（MoKα）=1.47 mm-1,the final R=0.0735 and wR=0.2457.In total,5585 independent reflections including 3727 observed ones with I 〉 2σ（I） were collected.The dihedral angle between naphthyl and substituted quinolyl and that between phenyl and substituted quinolyl are 61.2（1） and 108.2（1）°,respectively.Through C-H…O and C-H…N hydrogen bonds among molecules,the whole molecule is stacked into a three-dimensional structure.In addition,π-π stacking among adjacent naphthalene rings makes the molecule more stable,and the morpholine ring adopts a chair conformation.The target molecule exhibits good antibacterial activity.展开更多
Crystals of scandium magnesium aluminate, ScAlMgO4, were grown from the melt prepared from stoichiometric quantities of Sc2O3, Al2O3 and MgO. Single-crystal X-ray diffraction indicates that ScAlMgO4 crystallizes in th...Crystals of scandium magnesium aluminate, ScAlMgO4, were grown from the melt prepared from stoichiometric quantities of Sc2O3, Al2O3 and MgO. Single-crystal X-ray diffraction indicates that ScAlMgO4 crystallizes in the space group R3 m with a = b = 3.2506（9） A, c = 25.152（8）A, V= 230.16（11）A^3, Z= 3, F（000） = 234,μ = 2.424 cm^-1, the final R = 0.0381 and wR = 0.1061 for 1874 observed reflections with I 〉 2σ（I）. In ScAlMgO4, all Sc atoms are coordinated octahedrally, whereas AI or Mg atoms are forming a tetrahedron, or in a triangular bipyramid if one distant O atom is included. The structure of ScAlMgO4 is characterized by { [AlMgO4]^3-}∞^2 layers parallel to the ab plane, and they are further connected into a 3-dimen-sional framework by Sc atoms via O（1） atoms between the layers.展开更多
Four new deficient compounds in the R6B2C2QI4 family, LasCaSn2.75S4 1, Y6A10.67Ge2S14 2, Er5.33Si4S14 3 and Er4Ge4SI4 4, have been obtained via a precursor/flux method. Single-crystal analysis indicated that their cry...Four new deficient compounds in the R6B2C2QI4 family, LasCaSn2.75S4 1, Y6A10.67Ge2S14 2, Er5.33Si4S14 3 and Er4Ge4SI4 4, have been obtained via a precursor/flux method. Single-crystal analysis indicated that their crystal structures consist of three types of building blocks： RS7 （R = La/Ca for 1, R = Y for 2, R = Er for 3 and 4） mono-triangonal prism, CS6 （C = A1 for 1, C = Sn（2） for 2, C = Si（2） for 3, C = Ge（2） for 4） octahedron, and BS4 （B = Si for 1, B = Sn（1） for 2, B = Si（1） for 3, B = Ge（1） for 4） tetrahedron, as any other compounds belong to the R6B2C2Q14 family.展开更多
Two new quaternary sulfides,La3Sn0.25GeS71 and Sm3 Sn0.25GeS72,have been synthesized by a facile solid-state reaction,and their crystal structures were determined by singlecrystal X-ray diffraction analysis.The two co...Two new quaternary sulfides,La3Sn0.25GeS71 and Sm3 Sn0.25GeS72,have been synthesized by a facile solid-state reaction,and their crystal structures were determined by singlecrystal X-ray diffraction analysis.The two compounds crystallize in the P6 3 space group,and the crystal data are as follows-La3Sn0.25GeS7：a=10.3335（7）,c=5.8455（7）,Z=2;Sm3Sn0.25GeS7：a=9.999（3）,c=5.787（2）,Z=2.Single-crystal analysis indicated that the two compounds consist of three types of building blocks：LnS 8 anti-tetragonal prism,SnS 6 octahedron,and GeS 4 tetrahedron.展开更多
A new boron compound [C27H21BN4O3] based on 2-(2?-hydroxyphenyl)-1 Hbenzimidazole has been synthesized and characterized by single-crystal X-ray diffraction, and its crystal crystallizes in the monoclinic system, spac...A new boron compound [C27H21BN4O3] based on 2-(2?-hydroxyphenyl)-1 Hbenzimidazole has been synthesized and characterized by single-crystal X-ray diffraction, and its crystal crystallizes in the monoclinic system, space group P21/n with a = 9.6544(5), b = 14.1558(8), c = 16.4314(9) ?, β = 97.730°, Mr = 460.29, V = 2225.2(2) ?~3, Z = 4, Dc = 1.374 g/cm~3, μ = 0.74 mm-1, S = 1.051, F(000) = 960, the final R = 0.0643 and w R = 0.1569 for 2233 observed reflections(I > 2σ(I)). The title compound is a B(III) center mononuclear molecule in the asymmetric unit. The typical structural characteristic of the title compound is the methanol group adopting a μ2-bridging mode to link two different adjacent chelating modes though two types of hydrogen bonds to form a one-dimensional supramolecular structure. Additionally, aromatic π-π stacking interactions between adjacent benzimidazolyl groups lead to a three-dimensional network. Furthermore, the stability and fluorescence property revealed the potential applications in the organic photoelectric material.展开更多
As part of our systematic research on the acentric rare earth chalcogenides, the ErAlGeS5/KBr, Er3AgGeS7/KBr and Er6Ge3S14/KBr systems were investigated and three compounds belonging to the R6B2C2Q14 （R = rare earth,...As part of our systematic research on the acentric rare earth chalcogenides, the ErAlGeS5/KBr, Er3AgGeS7/KBr and Er6Ge3S14/KBr systems were investigated and three compounds belonging to the R6B2C2Q14 （R = rare earth, B = 6-coordinated element, C = 4-coordinated element, Q = S and Se） family were identified. These compounds crystallize in the P63 space group, and the crystal data are as follows： Er3Ge1/4GeS7, a = 9.6480（14）, c = 5.7920（12） A^°, Z = 2; Er3Ge0.382（8）GeS7, a = 9.6360（14）, c = 5.8460（12） A^°, Z = 2; Er3Ge1/2GeS7, a = 9.6061（13）, c = 5.8346（18）A^°, Z = 2. Single-crystal analysis indicated that the Er3GexGeS7 （x = 1/4, 0.382（8）, 1/2） structures consist of three types of building blocks： ErS7, GeS4 and GeS6 units. Er3MxGeS7 are deficient compounds with the B sites occupied partly by Ge（Ⅳ） and/or Ge（Ⅱ）.展开更多
Brown needle-like crystals of CaEr2S4 were isolated as the major product from a reaction of elements and binary sulfides by a two-step flux technique. CaEr2S4 crystallizes in the orthorhombic space group Pnma with a=1...Brown needle-like crystals of CaEr2S4 were isolated as the major product from a reaction of elements and binary sulfides by a two-step flux technique. CaEr2S4 crystallizes in the orthorhombic space group Pnma with a=12.845（4）, b=3.862（4）, c=13.001（2）（A）, V=645.0（7）（A）3,Z=4, F（000）=880,μ（MoKα）=27.794 mm^-1, the final R=0.0528 and wR=0.0562 for 1070observed reflections with I 〉 3σ（I）. The CaEr2S4 structure forms a three-dimensional framework that consists of interconnected tetra-octahedral Er4S18 fragments. Ca^2＋cations, in a monocapped trigonal prism geometry, are stuffed in two parallel rows into the one-dimensional channels along the b direction. CaEr2S4 is an infrared-transparent semiconductor with a band gap of 1.81 eV. Magnetic susceptibility measurements over 6～300 K indicate a Curie-Weiss paramagnetic behavior for the phase, with an effective magnetic moment of 9.64（1） μB per Er^3＋ ion.展开更多
The title compound, a novel Ag（Ⅰ） carboxyarylphosphonate [Ag（H2BCP）（4,4＇- bipy）]·2H2O （H3BCP = p-H2O3PCH2C6H4COOH, 4,4＇-bipy = 4,4＇-bipyridine）, was synthesized by a hydrothermal reaction and characte...The title compound, a novel Ag（Ⅰ） carboxyarylphosphonate [Ag（H2BCP）（4,4＇- bipy）]·2H2O （H3BCP = p-H2O3PCH2C6H4COOH, 4,4＇-bipy = 4,4＇-bipyridine）, was synthesized by a hydrothermal reaction and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. It belongs to monoclinic system, space group P21/c with a = 5.7038（11）, b = 22.397（4）, c = 5.602（4） , β = 106.26（3）°, V = 1913.4（7） 3, Z = 4, C18H20N2O7PAg, Mr = 515.20, Dc = 1.788 g/cm3, μ = 1.182 mm–1, F（000） = 1040, the final R = 0.0404 and wR = 0.1216 for 4178 observed reflections with I 2σ（Ⅰ）. In the structure, the Ag（Ⅰ） cations are bridged by 4,4＇-bipy to give rise to 1D chains running along the b axis. These chains are linked further by the interactions of O （from BCP ligands） and Ag atoms to yield 2D layers. Hydrogen bonding interactions and weak π-π stacking interactions between 4,4＇-bipy rings assemble such adjacent layers to generate a 3D supramolecular architecture.展开更多
A new Zn（II） phosphonate complex, [Zn3（PhPO3）2（PhPO3H）2（Phen）2]n （Phen = 1,10-phenanthroline）, has been synthesized and structurally determined by X-ray single-crystal diffraction. The complex crystallizes i...A new Zn（II） phosphonate complex, [Zn3（PhPO3）2（PhPO3H）2（Phen）2]n （Phen = 1,10-phenanthroline）, has been synthesized and structurally determined by X-ray single-crystal diffraction. The complex crystallizes in the monoclinic system, space group C2/c with a = 14.997（3）, b = 18.108（4）, c = 17.237（3） A, β = 96.61（3）°, V = 4649.9（16） A3, Z = 4, C48H38N4O12P4Zn3, Mr = 1182.87, Dc = 1.690 g/cm3^,μ = 1.743 mm^-1, F（000） = 2400, the final R = 0.0363 and wR = 0.0963. In the structure, the connectivity between two 5-coordinated Zn（II） atoms and four phosphonates as well as two Phen ligands form a Zn2（PhPO3H）2（PhPO3）2（Phen）2 unit, and such a neighboring unit is bridged by 4-coordinated Zn（II） to give rise to a 1D chain along the c axis. The π-π stacking interactions between Phen rings assemble adjacent chains packed together to form a 3D supermolecular architecture.展开更多
The new chiral clusters [h5-C5H4C(NR)CH3]RuNiM(CO)5(m3-S) (R = NH-C6H3-2,4- (NO2)2, M = Mo, 3; M = W, 4) were synthesized and the structure of cluster 3 was determined by single-crystal X-ray analysis. Crystal data: C...The new chiral clusters [h5-C5H4C(NR)CH3]RuNiM(CO)5(m3-S) (R = NH-C6H3-2,4- (NO2)2, M = Mo, 3; M = W, 4) were synthesized and the structure of cluster 3 was determined by single-crystal X-ray analysis. Crystal data: C23H16O9N4MoNiRuS, Mr = 780.18, orthorhombic, space group Pbca with the following crystallographic parameters: a = 13.207(4), b = 16.036(5), c = 25.513(8) , Z = 8, V = 5403(3) 3, Dc = 1.918 g/cm3, m = 1.834 mm-1 and F(000) = 3072. The final R = 0.0512 and wR = 0.1132 for 2525 reflections with I > 2.00s(I).展开更多
The single crystals and powder of a Yavapaiite Structure phosphate,namely,PbSb0.5Fe0.5（PO4）2,were synthesized by solid state method and characterized by X-ray single-crystal diffraction and powder diffraction.The ti...The single crystals and powder of a Yavapaiite Structure phosphate,namely,PbSb0.5Fe0.5（PO4）2,were synthesized by solid state method and characterized by X-ray single-crystal diffraction and powder diffraction.The title compound crystallizes in the monoclinic system,space group C2/c（No.15） with a = 16.716（4）,b = 5.186（7）,c = 8.130（2）A,β = 114.93（6）°,Z = 4,R（I 〉 2s（I）） = 0.0430,R indices（all data） = 0.0460,and T = 293（2） K.The title compound belongs to the Yavapaiite Structure A^（Ⅱ）M^（Ⅳ）（PO4）2 compounds,and the Sb1 atom and Fe1 atoms occupy the same site（M） and their occupancy factors are refined to be 0.5 and 0.5 having a sum occupancy factor of 1.0.Its structure consists of [M（PO）4]n^2n- layers running parallel to the（b,c） plane built up of cornerconnected MO6 octahedra and PO4 tetrahedra.Additionally,the calculations of energy band structure,and density of states have been performed with the density functional theory method.The studies of computational calculation and UV experimental results show that the new compound is an indirect band-gap insulator.展开更多
Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on...Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina ores.The results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO concentration.Fourier transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO substitution.Deconvolution of the Raman spectra showed that the average number of bridging oxygens per Si atom and the X_(Q^(3))/X_(Q^(2))(X_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents increased.Structural analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO substitution.However,bond strength is another important factor affecting the slag viscosity.The occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.展开更多
With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite h...With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite heterogeneous interface are constructed successfully to optimize the electromagnetic loss capacity.The macro–micro-synergistic graphene aerogel formed by the ice template‑assisted 3D printing strategy is cut by silicon carbide nanowires(SiC_(nws))grown in situ,while boron nitride(BN)interfacial structure is introduced on graphene nanoplates.The unique composite structure forces multiple scattering of incident EMWs,ensuring the combined effects of interfacial polarization,conduction networks,and magnetic-dielectric synergy.Therefore,the as-prepared composites present a minimum reflection loss value of−37.8 dB and a wide effective absorption bandwidth(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 mm.Besides,relying on the intrinsic high-temperature resistance of SiC_(nws) and BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h.展开更多
To expand the study on the structures and biological activities of the anthracyclines anticancer drugs and reduce their toxic side effects,the new anthraquinone derivatives,9‑pyridylanthrahydrazone(9‑PAH)and 9,10‑bisp...To expand the study on the structures and biological activities of the anthracyclines anticancer drugs and reduce their toxic side effects,the new anthraquinone derivatives,9‑pyridylanthrahydrazone(9‑PAH)and 9,10‑bispyridylanthrahydrazone(9,10‑PAH)were designed and synthesized.Utilizing 9‑PAH and 9,10‑PAH as promising anticancer ligands,their respective copper complexes,namely[Cu(L1)Cl_(2)]Cl(1)and{[Cu_(4)(μ_(2)‑Cl)_(3)Cl_(4)(9,10‑PAH)_(2)(DMSO)_(2)]Cl_(2)}_(n)(2),were subsequently synthesized,where the new ligand L1 is formed by coupling two 9‑PAH ligands in the coordination reaction.The chemical and crystal structures of 1 and 2 were elucidated by IR,MS,elemental analysis,and single‑crystal X‑ray diffraction.Complex 1 forms a mononuclear structure.L1 coordinates with Cu through its three N atoms,together with two Cl atoms,to form a five‑coordinated square pyramidal geometry.Complex 2 constitutes a polymeric structure,wherein each structural unit centrosymmetrically encompasses two five‑coordinated binuclear copper complexes(Cu1,Cu2)of 9,10‑PAH,with similar square pyramidal geometry.A chlorine atom(Cl_(2)),located at the symmetry center,bridges Cu1 and Cu1A to connect the two binuclear copper structures.Meanwhile,the two five‑coordinated Cu2 atoms symmetrically bridge the adjacent structural units via one coordinated Cl atom,respectively,thus forming a 1D chain‑like polymeric structure.In vitro anticancer activity assessments revealed that 1 and 2 showed significant cytotoxicity even higher than cisplatin.Specifically,the IC_(50)values of 2 against HeLa‑229 and SK‑OV‑3 cancer cell lines were determined to be(5.92±0.32)μmol·L^(-1)and(6.48±0.39)μmol·L^(-1),respectively.2 could also block the proliferation of HeLa‑229 cells in S phase and significantly induce cell apoptosis.In addition,fluorescence quenching competition experiments suggested that 2 might interact with DNA by an intercalative binding mode,offering insights into its underlying anticancer mechanism.CCDC:2388918,1;2388919,2.展开更多
Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler ...Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler metals is ever-increasing.It is of great significance to investigate the optimized composition design methods and to establish systematic design guidelines for brazing filler metals.This study elucidated the fundamental rules for the composition design of brazing filler metals from a three-dimensional perspective encompassing the basic properties of applied brazing filler metals,formability and processability,and overall cost.The basic properties of brazing filler metals refer to their mechanical properties,physicochemical properties,electromagnetic properties,corrosion resistance,and the wettability and fluidity during brazing.The formability and processability of brazing filler metals include the processes of smelting and casting,extrusion,rolling,drawing and ring-making,as well as the processes of granulation,powder production,and the molding of amorphous and microcrystalline structures.The cost of brazing filler metals corresponds to the sum of materials value and manufacturing cost.Improving the comprehensive properties of brazing filler metals requires a comprehensive and systematic consideration of design indicators.Highlighting the unique characteristics of brazing filler metals should focus on relevant technical indicators.Binary or ternary eutectic structures can effectively enhance the flow spreading ability of brazing filler metals,and solid solution structures contribute to the formability.By employing the proposed design guidelines,typical Ag based,Cu based,Zn based brazing filler metals,and Sn based solders were designed and successfully applied in major scientific and engineering projects.展开更多
As-forged WSTi6421 titanium alloy billet afterβannealing was investigated.Abnormally coarse grains larger than adjacent grains could be observed in the microstructures,forming abnormal grain structures with uneven si...As-forged WSTi6421 titanium alloy billet afterβannealing was investigated.Abnormally coarse grains larger than adjacent grains could be observed in the microstructures,forming abnormal grain structures with uneven size distribution.Through electron backscattered diffraction(EBSD),the forged microstructure at various locations of as-forged WSTi6421 titanium alloy billet was analyzed,revealing that the strength of theβphase cubic texture generated by forging significantly influences the grain size afterβannealing.Heat treatment experiments were conducted within the temperature range from T_(β)−50°C to T_(β)+10°C to observe the macro-and micro-morphologies.Results show that the cubic texture ofβphase caused by forging impacts the texture of the secondaryαphase,which subsequently influences theβphase formed during the post-βannealing process.Moreover,the pinning effect of the residual primaryαphase plays a crucial role in the growth ofβgrains during theβannealing process.EBSD analysis results suggest that the strength ofβphase with cubic texture formed during forging process impacts the orientation distribution differences ofβgrains afterβannealing.Additionally,the development of grains with large orientations within the cubic texture shows a certain degree of selectivity duringβannealing,which is affected by various factors,including the pinning effect of the primaryαphase,the strength of the matrix cubic texture,and the orientation relationship betweenβgrain and matrix.Comprehensively,the stronger the texture in a certain region,the less likely the large misoriented grains suffering secondary growth,thereby aggregating the difference in microstructure and grain orientation distribution across different regions afterβannealing.展开更多
As the proportion of composite materials used in aircraft continues to increase, the electromagnetic Shielding Effectiveness (SE) of these materials becomes a critical factor in the electromagnetic safety design of ai...As the proportion of composite materials used in aircraft continues to increase, the electromagnetic Shielding Effectiveness (SE) of these materials becomes a critical factor in the electromagnetic safety design of aircraft structures. The assessment of electromagnetic SE for Slotted Composite Structures(SCSs) is particularly challenging due to their complex geometries and there remains a lack of suitable models for accurately predicting the SE performance of these intricate configurations. To address this issue, this paper introduces SCS-Net, a Deep Neural Network (DNN) method designed to accurately predict the SE of SCS. This method considers the impacts of various structural parameters, material properties and incident wave parameters on the SE of SCSs. In order to better model the SCS, an improved Nicolson-Ross-Weir (NRW) method is introduced in this paper to provide an equivalent flat structure for the SCS and to calculate the electromagnetic parameters of the equivalent structure. Additionally, the prediction of SE via DNNs is limited by insufficient test data, which hinders support for large-sample training. To address the issue of limited measured data, this paper develops a Measurement-Computation Fusion (MCF) dataset construction method. The predictions based on the simulation results show that the proposed method maintains an error of less than 0.07 dB within the 8–10 GHz frequency range. Furthermore, a new loss function based on the weighted L1-norm is established to improve the prediction accuracy for these parameters. Compared with traditional loss functions, the new loss function reduces the maximum prediction error for equivalent electromagnetic parameters by 47%. This method significantly improves the prediction accuracy of SCS-Net for measured data, with a maximum improvement of 23.88%. These findings demonstrate that the proposed method enables precise SE prediction and design for composite structures while reducing the number of test samples needed.展开更多
The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-...The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-heterostructured nanoporous CoFe/CoFe_(2)O_(4) and CeO_(2−x),in situ grown on nickel foam(NF),holds great promise as a high-efficient bifunctional electrocatalyst(named R-CoFe/Ce/NF)for water splitting.Experimental characterization verifies surface reconstruction from CoFe alloy/oxide to highly active CoFeOOH during in situ electrochemical polarization.By virtues of three-dimensional nanoporous architecture and abundant electroactive CoFeOOH/CeO_(2−x) heterostructure interfaces,the R-CoFe/Ce/NF electrode achieves low overpotentials for oxygen evolution(η_(10)=227 mV;η_(500)=450 mV)and hydrogen evolution(η_(10)=35 mV;η_(408)=560 mV)reactions with high normalized electrochemical active surface areas,respectively.Additionally,the alkaline full water splitting electrolyzer of R-CoFe/Ce/NF||R-CoFe/Ce/NF achieves a current density of 50 mA·cm^(−2) only at 1.75 V;the decline of activity is satisfactory after 100-h durability test at 300 mA·cm^(−2).Density functional theory also demonstrates that the electron can transfer from CeO_(2−x) by virtue of O atom to CoFeOOH at CoFeOOH/CeO_(2−x) heterointerfaces and enhancing the adsorption of reactant,thus optimizing electronic structure and Gibbs free energies for the improvement of the activity for water splitting.展开更多
A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of t...A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of the creep rate during the creep fracture process and the microstructure evolution before and after creep were investigated,thereby revealing the creep fracture mechanism of the new nickel-based single-crystal superalloy.The results indicate that the creep life of the alloy is 104.5 h,and the strain can reach 33.58%.The creep rate decreases first,then increases,and finally tends to be stable until fracture.At the initial stage of creep,the creep rate decreases first,then rises and finally decreases again with time.Furthermore,the creep fracture microstructure is composed of dimples and tearing edges without obvious slip planes.Oxides and recrystallized structures exist inside the fracture surface,and the voids inside the fracture are elongated and perpendicular to the stress axis,showing a fracture mechanism of microcrack accumulation.展开更多
The rapid development of 5G communication technology and smart electronic and electrical equipment will inevitably lead to electromagnetic radiation pollution.Enriching heterointerface polarization relaxation through ...The rapid development of 5G communication technology and smart electronic and electrical equipment will inevitably lead to electromagnetic radiation pollution.Enriching heterointerface polarization relaxation through nanostructure design and interface modifica-tion has proven to be an effective strategy to obtain efficient electromagnetic wave absorption.Here,this work implements an innovative method that combines biomimetic honeycomb superstructure to constrain hierarchical porous heterostructure composed of Co/CoO nano-particles to improve the interfacial polarization intensity.The method effectively controlled the absorption efficiency of Co^(2+)through de-lignification modification of bamboo,and combined with the bionic carbon-based natural hierarchical porous structure to achieve uniform dispersion of nanoparticles,which is conducive to the in-depth construction of heterogeneous interfaces.In addition,the multiphase struc-ture brought about by high-temperature pyrolysis provides the best dielectric loss and impedance matching for the material.Therefore,the obtained bamboo-based Co/CoO multiphase composite showed excellent electromagnetic wave absorption performance,achieving excel-lent reflection loss(RL)of-79 dB and effective absorption band width of 4.12 GHz(6.84-10.96 GHz)at low load of 15wt%.Among them,the material’s optimal radar cross-section(RCS)reduction value can reach 31.9 dB·m^(2).This work provides a new approach to the micro-control and comprehensive optimization of macro-design of microwave absorbers,and offers new ideas for the high-value utiliza-tion of biomass materials.展开更多
文摘The halogenated hydrocarbon amination reaction between the original raw mate-rial N-（（6-bromine-2-methoxylquinoline-3-yl）benzyl）-3-chlorine-N-（naphthalene-1-yl）propionamide and morpholine produces the target molecule N-（（6-bromine-2-methoxylquinoline-3-yl）benzyl）-3-morpholine-N-（naphthalene-1-yl）propionamide （C34H32BrN3O3,Mr=610.54）,and its structure was characterized by 1H NMR,IR,H RMS and X-ray single-crystal diffraction.This crystal is of triclinic system,space group P1 with a=9.315（2）,b=10.3449（12）,c=15.901（3）,α=80.981（14）,β=76.996（17）,γ=74.917（13）°,V=1433.6（5）3,Z=2,Dc=1.414 g/cm3,F（000）= 632,μ（MoKα）=1.47 mm-1,the final R=0.0735 and wR=0.2457.In total,5585 independent reflections including 3727 observed ones with I 〉 2σ（I） were collected.The dihedral angle between naphthyl and substituted quinolyl and that between phenyl and substituted quinolyl are 61.2（1） and 108.2（1）°,respectively.Through C-H…O and C-H…N hydrogen bonds among molecules,the whole molecule is stacked into a three-dimensional structure.In addition,π-π stacking among adjacent naphthalene rings makes the molecule more stable,and the morpholine ring adopts a chair conformation.The target molecule exhibits good antibacterial activity.
基金supported by the Natual Science Foundation of Fujian Province (2006H0041)
文摘Crystals of scandium magnesium aluminate, ScAlMgO4, were grown from the melt prepared from stoichiometric quantities of Sc2O3, Al2O3 and MgO. Single-crystal X-ray diffraction indicates that ScAlMgO4 crystallizes in the space group R3 m with a = b = 3.2506（9） A, c = 25.152（8）A, V= 230.16（11）A^3, Z= 3, F（000） = 234,μ = 2.424 cm^-1, the final R = 0.0381 and wR = 0.1061 for 1874 observed reflections with I 〉 2σ（I）. In ScAlMgO4, all Sc atoms are coordinated octahedrally, whereas AI or Mg atoms are forming a tetrahedron, or in a triangular bipyramid if one distant O atom is included. The structure of ScAlMgO4 is characterized by { [AlMgO4]^3-}∞^2 layers parallel to the ab plane, and they are further connected into a 3-dimen-sional framework by Sc atoms via O（1） atoms between the layers.
基金Supported by NNSFC(90922035,21003126)the Key Project from CAS(KJCX2-YW-H01,KJCX2-EW-H03)NSF of Fujian Province(A0420002)
文摘Four new deficient compounds in the R6B2C2QI4 family, LasCaSn2.75S4 1, Y6A10.67Ge2S14 2, Er5.33Si4S14 3 and Er4Ge4SI4 4, have been obtained via a precursor/flux method. Single-crystal analysis indicated that their crystal structures consist of three types of building blocks： RS7 （R = La/Ca for 1, R = Y for 2, R = Er for 3 and 4） mono-triangonal prism, CS6 （C = A1 for 1, C = Sn（2） for 2, C = Si（2） for 3, C = Ge（2） for 4） octahedron, and BS4 （B = Si for 1, B = Sn（1） for 2, B = Si（1） for 3, B = Ge（1） for 4） tetrahedron, as any other compounds belong to the R6B2C2Q14 family.
基金Supported by the NNSF of China (20821061)Key Project from the CAS (KJCX2-YW-M10,KJCX2-EW-H03)the 973 Program (2009CB939801)
文摘Two new quaternary sulfides,La3Sn0.25GeS71 and Sm3 Sn0.25GeS72,have been synthesized by a facile solid-state reaction,and their crystal structures were determined by singlecrystal X-ray diffraction analysis.The two compounds crystallize in the P6 3 space group,and the crystal data are as follows-La3Sn0.25GeS7：a=10.3335（7）,c=5.8455（7）,Z=2;Sm3Sn0.25GeS7：a=9.999（3）,c=5.787（2）,Z=2.Single-crystal analysis indicated that the two compounds consist of three types of building blocks：LnS 8 anti-tetragonal prism,SnS 6 octahedron,and GeS 4 tetrahedron.
基金The research was supported by the Scientific and Technological Project of Henan Province(No.182102210102)the Key Scientific Research Project of Colleges and Universities of Henan Province(No.15A150061)the National Natural Science Foundation of China(Nos.21371154,61405054 and 21601156)
文摘A new boron compound [C27H21BN4O3] based on 2-(2?-hydroxyphenyl)-1 Hbenzimidazole has been synthesized and characterized by single-crystal X-ray diffraction, and its crystal crystallizes in the monoclinic system, space group P21/n with a = 9.6544(5), b = 14.1558(8), c = 16.4314(9) ?, β = 97.730°, Mr = 460.29, V = 2225.2(2) ?~3, Z = 4, Dc = 1.374 g/cm~3, μ = 0.74 mm-1, S = 1.051, F(000) = 960, the final R = 0.0643 and w R = 0.1569 for 2233 observed reflections(I > 2σ(I)). The title compound is a B(III) center mononuclear molecule in the asymmetric unit. The typical structural characteristic of the title compound is the methanol group adopting a μ2-bridging mode to link two different adjacent chelating modes though two types of hydrogen bonds to form a one-dimensional supramolecular structure. Additionally, aromatic π-π stacking interactions between adjacent benzimidazolyl groups lead to a three-dimensional network. Furthermore, the stability and fluorescence property revealed the potential applications in the organic photoelectric material.
基金Supported by the NSFC (20871115)the NSF of Fujian Province (2007J0173)+1 种基金the NSF of CAS (KJCX2.YW. M10)the 973 Program (2007CB936703)
文摘As part of our systematic research on the acentric rare earth chalcogenides, the ErAlGeS5/KBr, Er3AgGeS7/KBr and Er6Ge3S14/KBr systems were investigated and three compounds belonging to the R6B2C2Q14 （R = rare earth, B = 6-coordinated element, C = 4-coordinated element, Q = S and Se） family were identified. These compounds crystallize in the P63 space group, and the crystal data are as follows： Er3Ge1/4GeS7, a = 9.6480（14）, c = 5.7920（12） A^°, Z = 2; Er3Ge0.382（8）GeS7, a = 9.6360（14）, c = 5.8460（12） A^°, Z = 2; Er3Ge1/2GeS7, a = 9.6061（13）, c = 5.8346（18）A^°, Z = 2. Single-crystal analysis indicated that the Er3GexGeS7 （x = 1/4, 0.382（8）, 1/2） structures consist of three types of building blocks： ErS7, GeS4 and GeS6 units. Er3MxGeS7 are deficient compounds with the B sites occupied partly by Ge（Ⅳ） and/or Ge（Ⅱ）.
基金This work was partially supported by the NSF of Fujian Province (Z0513020, A042002)the NSF for Distinguished Young Scientist of China (20425104) and the NSF of CAS (KJCX2-SW-h05)
文摘Brown needle-like crystals of CaEr2S4 were isolated as the major product from a reaction of elements and binary sulfides by a two-step flux technique. CaEr2S4 crystallizes in the orthorhombic space group Pnma with a=12.845（4）, b=3.862（4）, c=13.001（2）（A）, V=645.0（7）（A）3,Z=4, F（000）=880,μ（MoKα）=27.794 mm^-1, the final R=0.0528 and wR=0.0562 for 1070observed reflections with I 〉 3σ（I）. The CaEr2S4 structure forms a three-dimensional framework that consists of interconnected tetra-octahedral Er4S18 fragments. Ca^2＋cations, in a monocapped trigonal prism geometry, are stuffed in two parallel rows into the one-dimensional channels along the b direction. CaEr2S4 is an infrared-transparent semiconductor with a band gap of 1.81 eV. Magnetic susceptibility measurements over 6～300 K indicate a Curie-Weiss paramagnetic behavior for the phase, with an effective magnetic moment of 9.64（1） μB per Er^3＋ ion.
基金supported by the National Natural Science Foundation of China (No. 20873021)the State Key Laboratory of Structural Chemistry and the Young Talent Programmed of Fujian Province (No. 2006F3072)
文摘The title compound, a novel Ag（Ⅰ） carboxyarylphosphonate [Ag（H2BCP）（4,4＇- bipy）]·2H2O （H3BCP = p-H2O3PCH2C6H4COOH, 4,4＇-bipy = 4,4＇-bipyridine）, was synthesized by a hydrothermal reaction and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. It belongs to monoclinic system, space group P21/c with a = 5.7038（11）, b = 22.397（4）, c = 5.602（4） , β = 106.26（3）°, V = 1913.4（7） 3, Z = 4, C18H20N2O7PAg, Mr = 515.20, Dc = 1.788 g/cm3, μ = 1.182 mm–1, F（000） = 1040, the final R = 0.0404 and wR = 0.1216 for 4178 observed reflections with I 2σ（Ⅰ）. In the structure, the Ag（Ⅰ） cations are bridged by 4,4＇-bipy to give rise to 1D chains running along the b axis. These chains are linked further by the interactions of O （from BCP ligands） and Ag atoms to yield 2D layers. Hydrogen bonding interactions and weak π-π stacking interactions between 4,4＇-bipy rings assemble such adjacent layers to generate a 3D supramolecular architecture.
基金supported by the State Key Laboratory of Structural Chemistry,and the Young Talent Programmed of Fujian Province (No 2006F3072)
文摘A new Zn（II） phosphonate complex, [Zn3（PhPO3）2（PhPO3H）2（Phen）2]n （Phen = 1,10-phenanthroline）, has been synthesized and structurally determined by X-ray single-crystal diffraction. The complex crystallizes in the monoclinic system, space group C2/c with a = 14.997（3）, b = 18.108（4）, c = 17.237（3） A, β = 96.61（3）°, V = 4649.9（16） A3, Z = 4, C48H38N4O12P4Zn3, Mr = 1182.87, Dc = 1.690 g/cm3^,μ = 1.743 mm^-1, F（000） = 2400, the final R = 0.0363 and wR = 0.0963. In the structure, the connectivity between two 5-coordinated Zn（II） atoms and four phosphonates as well as two Phen ligands form a Zn2（PhPO3H）2（PhPO3）2（Phen）2 unit, and such a neighboring unit is bridged by 4-coordinated Zn（II） to give rise to a 1D chain along the c axis. The π-π stacking interactions between Phen rings assemble adjacent chains packed together to form a 3D supermolecular architecture.
基金This work was supported by the National Natural Science Foundation of China
文摘The new chiral clusters [h5-C5H4C(NR)CH3]RuNiM(CO)5(m3-S) (R = NH-C6H3-2,4- (NO2)2, M = Mo, 3; M = W, 4) were synthesized and the structure of cluster 3 was determined by single-crystal X-ray analysis. Crystal data: C23H16O9N4MoNiRuS, Mr = 780.18, orthorhombic, space group Pbca with the following crystallographic parameters: a = 13.207(4), b = 16.036(5), c = 25.513(8) , Z = 8, V = 5403(3) 3, Dc = 1.918 g/cm3, m = 1.834 mm-1 and F(000) = 3072. The final R = 0.0512 and wR = 0.1132 for 2525 reflections with I > 2.00s(I).
基金Supported by the National Natural Science Foundation of China(21101156 and 61376002)State Key Laboratory of Structure Chemistry(No.20150016)+1 种基金Outstanding Youth of Colleges and Universities of Department of Education,Fujian Province Natural Science Foundation for Youths(No.2016J05109)Fujian Education Department(No.JK2015056)
文摘The single crystals and powder of a Yavapaiite Structure phosphate,namely,PbSb0.5Fe0.5（PO4）2,were synthesized by solid state method and characterized by X-ray single-crystal diffraction and powder diffraction.The title compound crystallizes in the monoclinic system,space group C2/c（No.15） with a = 16.716（4）,b = 5.186（7）,c = 8.130（2）A,β = 114.93（6）°,Z = 4,R（I 〉 2s（I）） = 0.0430,R indices（all data） = 0.0460,and T = 293（2） K.The title compound belongs to the Yavapaiite Structure A^（Ⅱ）M^（Ⅳ）（PO4）2 compounds,and the Sb1 atom and Fe1 atoms occupy the same site（M） and their occupancy factors are refined to be 0.5 and 0.5 having a sum occupancy factor of 1.0.Its structure consists of [M（PO）4]n^2n- layers running parallel to the（b,c） plane built up of cornerconnected MO6 octahedra and PO4 tetrahedra.Additionally,the calculations of energy band structure,and density of states have been performed with the density functional theory method.The studies of computational calculation and UV experimental results show that the new compound is an indirect band-gap insulator.
基金financially supported by the National Natural Science Foundation of China(Nos.52425408 and 52304345)the Fundamental Research Funds for the Central Universities,China(No.2023CDJXY-016)the Postdoctoral Science Foundation of Chongqing(No.CSTB2023NSCQ-BHX0174)。
文摘Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina ores.The results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO concentration.Fourier transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO substitution.Deconvolution of the Raman spectra showed that the average number of bridging oxygens per Si atom and the X_(Q^(3))/X_(Q^(2))(X_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents increased.Structural analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO substitution.However,bond strength is another important factor affecting the slag viscosity.The occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.
基金sponsored by National Natural Science Foundation of China(No.52302121,No.52203386)Shanghai Sailing Program(No.23YF1454700)+1 种基金Shanghai Natural Science Foundation(No.23ZR1472700)Shanghai Post-doctoral Excellent Program(No.2022664).
文摘With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite heterogeneous interface are constructed successfully to optimize the electromagnetic loss capacity.The macro–micro-synergistic graphene aerogel formed by the ice template‑assisted 3D printing strategy is cut by silicon carbide nanowires(SiC_(nws))grown in situ,while boron nitride(BN)interfacial structure is introduced on graphene nanoplates.The unique composite structure forces multiple scattering of incident EMWs,ensuring the combined effects of interfacial polarization,conduction networks,and magnetic-dielectric synergy.Therefore,the as-prepared composites present a minimum reflection loss value of−37.8 dB and a wide effective absorption bandwidth(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 mm.Besides,relying on the intrinsic high-temperature resistance of SiC_(nws) and BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h.
文摘To expand the study on the structures and biological activities of the anthracyclines anticancer drugs and reduce their toxic side effects,the new anthraquinone derivatives,9‑pyridylanthrahydrazone(9‑PAH)and 9,10‑bispyridylanthrahydrazone(9,10‑PAH)were designed and synthesized.Utilizing 9‑PAH and 9,10‑PAH as promising anticancer ligands,their respective copper complexes,namely[Cu(L1)Cl_(2)]Cl(1)and{[Cu_(4)(μ_(2)‑Cl)_(3)Cl_(4)(9,10‑PAH)_(2)(DMSO)_(2)]Cl_(2)}_(n)(2),were subsequently synthesized,where the new ligand L1 is formed by coupling two 9‑PAH ligands in the coordination reaction.The chemical and crystal structures of 1 and 2 were elucidated by IR,MS,elemental analysis,and single‑crystal X‑ray diffraction.Complex 1 forms a mononuclear structure.L1 coordinates with Cu through its three N atoms,together with two Cl atoms,to form a five‑coordinated square pyramidal geometry.Complex 2 constitutes a polymeric structure,wherein each structural unit centrosymmetrically encompasses two five‑coordinated binuclear copper complexes(Cu1,Cu2)of 9,10‑PAH,with similar square pyramidal geometry.A chlorine atom(Cl_(2)),located at the symmetry center,bridges Cu1 and Cu1A to connect the two binuclear copper structures.Meanwhile,the two five‑coordinated Cu2 atoms symmetrically bridge the adjacent structural units via one coordinated Cl atom,respectively,thus forming a 1D chain‑like polymeric structure.In vitro anticancer activity assessments revealed that 1 and 2 showed significant cytotoxicity even higher than cisplatin.Specifically,the IC_(50)values of 2 against HeLa‑229 and SK‑OV‑3 cancer cell lines were determined to be(5.92±0.32)μmol·L^(-1)and(6.48±0.39)μmol·L^(-1),respectively.2 could also block the proliferation of HeLa‑229 cells in S phase and significantly induce cell apoptosis.In addition,fluorescence quenching competition experiments suggested that 2 might interact with DNA by an intercalative binding mode,offering insights into its underlying anticancer mechanism.CCDC:2388918,1;2388919,2.
基金National Natural Science Foundation of China(U22A20191)。
文摘Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler metals is ever-increasing.It is of great significance to investigate the optimized composition design methods and to establish systematic design guidelines for brazing filler metals.This study elucidated the fundamental rules for the composition design of brazing filler metals from a three-dimensional perspective encompassing the basic properties of applied brazing filler metals,formability and processability,and overall cost.The basic properties of brazing filler metals refer to their mechanical properties,physicochemical properties,electromagnetic properties,corrosion resistance,and the wettability and fluidity during brazing.The formability and processability of brazing filler metals include the processes of smelting and casting,extrusion,rolling,drawing and ring-making,as well as the processes of granulation,powder production,and the molding of amorphous and microcrystalline structures.The cost of brazing filler metals corresponds to the sum of materials value and manufacturing cost.Improving the comprehensive properties of brazing filler metals requires a comprehensive and systematic consideration of design indicators.Highlighting the unique characteristics of brazing filler metals should focus on relevant technical indicators.Binary or ternary eutectic structures can effectively enhance the flow spreading ability of brazing filler metals,and solid solution structures contribute to the formability.By employing the proposed design guidelines,typical Ag based,Cu based,Zn based brazing filler metals,and Sn based solders were designed and successfully applied in major scientific and engineering projects.
基金Key Research and Development Plan of Shaanxi Province(2023-YBGY-493)。
文摘As-forged WSTi6421 titanium alloy billet afterβannealing was investigated.Abnormally coarse grains larger than adjacent grains could be observed in the microstructures,forming abnormal grain structures with uneven size distribution.Through electron backscattered diffraction(EBSD),the forged microstructure at various locations of as-forged WSTi6421 titanium alloy billet was analyzed,revealing that the strength of theβphase cubic texture generated by forging significantly influences the grain size afterβannealing.Heat treatment experiments were conducted within the temperature range from T_(β)−50°C to T_(β)+10°C to observe the macro-and micro-morphologies.Results show that the cubic texture ofβphase caused by forging impacts the texture of the secondaryαphase,which subsequently influences theβphase formed during the post-βannealing process.Moreover,the pinning effect of the residual primaryαphase plays a crucial role in the growth ofβgrains during theβannealing process.EBSD analysis results suggest that the strength ofβphase with cubic texture formed during forging process impacts the orientation distribution differences ofβgrains afterβannealing.Additionally,the development of grains with large orientations within the cubic texture shows a certain degree of selectivity duringβannealing,which is affected by various factors,including the pinning effect of the primaryαphase,the strength of the matrix cubic texture,and the orientation relationship betweenβgrain and matrix.Comprehensively,the stronger the texture in a certain region,the less likely the large misoriented grains suffering secondary growth,thereby aggregating the difference in microstructure and grain orientation distribution across different regions afterβannealing.
基金supported by the National Natural Science Foundation of China(Nos.62101020 and 62141405)the Special Scientific Research Project of Civil Aircraft,China(No.MJZ5-2N22).
文摘As the proportion of composite materials used in aircraft continues to increase, the electromagnetic Shielding Effectiveness (SE) of these materials becomes a critical factor in the electromagnetic safety design of aircraft structures. The assessment of electromagnetic SE for Slotted Composite Structures(SCSs) is particularly challenging due to their complex geometries and there remains a lack of suitable models for accurately predicting the SE performance of these intricate configurations. To address this issue, this paper introduces SCS-Net, a Deep Neural Network (DNN) method designed to accurately predict the SE of SCS. This method considers the impacts of various structural parameters, material properties and incident wave parameters on the SE of SCSs. In order to better model the SCS, an improved Nicolson-Ross-Weir (NRW) method is introduced in this paper to provide an equivalent flat structure for the SCS and to calculate the electromagnetic parameters of the equivalent structure. Additionally, the prediction of SE via DNNs is limited by insufficient test data, which hinders support for large-sample training. To address the issue of limited measured data, this paper develops a Measurement-Computation Fusion (MCF) dataset construction method. The predictions based on the simulation results show that the proposed method maintains an error of less than 0.07 dB within the 8–10 GHz frequency range. Furthermore, a new loss function based on the weighted L1-norm is established to improve the prediction accuracy for these parameters. Compared with traditional loss functions, the new loss function reduces the maximum prediction error for equivalent electromagnetic parameters by 47%. This method significantly improves the prediction accuracy of SCS-Net for measured data, with a maximum improvement of 23.88%. These findings demonstrate that the proposed method enables precise SE prediction and design for composite structures while reducing the number of test samples needed.
基金sponsored by the National Natural Science Foundation of China(Nos.5210125 and 52375422)the Science Research Project of Hebei Education Department(No.BJK2023058)the Natural Science Foundation of Hebei Province(Nos.E2020208069,B2020208083 and E202320801).
文摘The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-heterostructured nanoporous CoFe/CoFe_(2)O_(4) and CeO_(2−x),in situ grown on nickel foam(NF),holds great promise as a high-efficient bifunctional electrocatalyst(named R-CoFe/Ce/NF)for water splitting.Experimental characterization verifies surface reconstruction from CoFe alloy/oxide to highly active CoFeOOH during in situ electrochemical polarization.By virtues of three-dimensional nanoporous architecture and abundant electroactive CoFeOOH/CeO_(2−x) heterostructure interfaces,the R-CoFe/Ce/NF electrode achieves low overpotentials for oxygen evolution(η_(10)=227 mV;η_(500)=450 mV)and hydrogen evolution(η_(10)=35 mV;η_(408)=560 mV)reactions with high normalized electrochemical active surface areas,respectively.Additionally,the alkaline full water splitting electrolyzer of R-CoFe/Ce/NF||R-CoFe/Ce/NF achieves a current density of 50 mA·cm^(−2) only at 1.75 V;the decline of activity is satisfactory after 100-h durability test at 300 mA·cm^(−2).Density functional theory also demonstrates that the electron can transfer from CeO_(2−x) by virtue of O atom to CoFeOOH at CoFeOOH/CeO_(2−x) heterointerfaces and enhancing the adsorption of reactant,thus optimizing electronic structure and Gibbs free energies for the improvement of the activity for water splitting.
基金China Postdoctoral Science Foundation General Project(2024M760034)Postdoctoral Research Programs of Anhui Province(2024A774)。
文摘A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of the creep rate during the creep fracture process and the microstructure evolution before and after creep were investigated,thereby revealing the creep fracture mechanism of the new nickel-based single-crystal superalloy.The results indicate that the creep life of the alloy is 104.5 h,and the strain can reach 33.58%.The creep rate decreases first,then increases,and finally tends to be stable until fracture.At the initial stage of creep,the creep rate decreases first,then rises and finally decreases again with time.Furthermore,the creep fracture microstructure is composed of dimples and tearing edges without obvious slip planes.Oxides and recrystallized structures exist inside the fracture surface,and the voids inside the fracture are elongated and perpendicular to the stress axis,showing a fracture mechanism of microcrack accumulation.
基金supported by the National Key R&D Program of China(Nos.2023YFE0108300 and 2023YFD2202103)the National Natural Science Foundation of China(No.32371972)+2 种基金the Natural Science Foundation of Jiangsu Province,China(No.BK20221336)Jiangsu Agricultural Science and Technology Independent Innovation Fund,China(No.CX(23)3060)Jiangxi Forestry Bureau Forestry Science and Technology Innovation Special Project,China(No.202240).
文摘The rapid development of 5G communication technology and smart electronic and electrical equipment will inevitably lead to electromagnetic radiation pollution.Enriching heterointerface polarization relaxation through nanostructure design and interface modifica-tion has proven to be an effective strategy to obtain efficient electromagnetic wave absorption.Here,this work implements an innovative method that combines biomimetic honeycomb superstructure to constrain hierarchical porous heterostructure composed of Co/CoO nano-particles to improve the interfacial polarization intensity.The method effectively controlled the absorption efficiency of Co^(2+)through de-lignification modification of bamboo,and combined with the bionic carbon-based natural hierarchical porous structure to achieve uniform dispersion of nanoparticles,which is conducive to the in-depth construction of heterogeneous interfaces.In addition,the multiphase struc-ture brought about by high-temperature pyrolysis provides the best dielectric loss and impedance matching for the material.Therefore,the obtained bamboo-based Co/CoO multiphase composite showed excellent electromagnetic wave absorption performance,achieving excel-lent reflection loss(RL)of-79 dB and effective absorption band width of 4.12 GHz(6.84-10.96 GHz)at low load of 15wt%.Among them,the material’s optimal radar cross-section(RCS)reduction value can reach 31.9 dB·m^(2).This work provides a new approach to the micro-control and comprehensive optimization of macro-design of microwave absorbers,and offers new ideas for the high-value utiliza-tion of biomass materials.
