A new kind offl biomedical titanium alloy, Ti-35Nb-4Sn-6Mo-9Zr, composed of non-toxic elements Nb, Mo, Zr and Sn with lower elastic modulus and higher strength was designed based on d-electron alloy design theory and ...A new kind offl biomedical titanium alloy, Ti-35Nb-4Sn-6Mo-9Zr, composed of non-toxic elements Nb, Mo, Zr and Sn with lower elastic modulus and higher strength was designed based on d-electron alloy design theory and JMatPro software using orthogonal experiment. The microstructure and basic mechanical properties of designed alloy were investigated. The results show that the alloy is composed of single fl equiaxed grains after solution treatment at 800 ~C. Compared with Ti-6A1-4V, the mechanical properties of the designed alloy are more excellent： E=65 GPa, σb=834 MPa, σ0.2=802 MPa, and σ=11%, which is expected to become a promising new type implanted material. The research approach adopted can reduce the experimental time and cost effectively, and get the ideal experimental results.展开更多
The coordination-dependent force fleld of TersofF for covalently bonded Si has been used tocalculate the cleavage force as a function of interplanar separation and hence to estimate surfaceenergies. This force field i...The coordination-dependent force fleld of TersofF for covalently bonded Si has been used tocalculate the cleavage force as a function of interplanar separation and hence to estimate surfaceenergies. This force field is already fitted to density functional results. The relation to bond-breaking and electron correlation will be emphasized. Finnis-Sinclair-type many-body potentialshave then been used to treat some d-electron metals. In particular, results for cleavage forcein bcc Fe will be presented, and also some calculations as two perfectly planar Fe surfaces arerubbed together' at different interplanar separations. Finally, lattice dynamical models for thesteady-state propagation of a screw dislocation, and then of a crack, will be used, again within abond-breaking type of force field. For the screw dislocation propagation. a solitary wave equationis shown to follow in the 'almost continuum' limit. Energy radiated by phonons as the dislocationmoves can thereby be calculated.展开更多
Electrocatalytic CO_(2) reduction reaction(CO_(2)RR)to high-value-added products is a crucial approach for promoting carbon recycling and mitigating energy challenges.Here,extensive theoretical screenings were conduct...Electrocatalytic CO_(2) reduction reaction(CO_(2)RR)to high-value-added products is a crucial approach for promoting carbon recycling and mitigating energy challenges.Here,extensive theoretical screenings were conducted on the nitrogen-doped graphene-supported heteronuclear dual-atom catalysts(DACs)M_(1)/M_(2)-NC(M=V,Cr,Mn,Fe,Co,Ni,and Cu)for CO_(2)RR using density functional theory(DFT)calculations.The calculations indicate that Mn/Cu-NC exhibits superior catalytic activity and selectivity for the CO_(2)RR to HCOOH with a limiting potential as low as−0.15 V.The superior performance is attributed to the strong d-electron coupling between Mn and Cu dual atoms in Mn/Cu-NC,which results in an upward shift of the d-band center of the Mn single atom closer to the Fermi level.Moreover,the adsorption of the key intermediate*OCHO on the Mn single atom was further enhanced,thereby reducing the limiting potential and improving the catalytic performance for CO_(2)RR.This work offers a comprehensive theoretical insight into the catalytic mechanism of the novel Mn/Cu-NC DAC for CO_(2)RR and establishes a critical descriptor of d-band center of the catalytic active center to determine the catalytic activity of DACs for CO_(2)RR,thereby providing guidance for the future design and fabrication of graphene-based metal DACs for CO_(2)RR.展开更多
基金Project(BE2011778)supported by Science and Technology Support Program of Jiangsu Province,ChinaProject(20133069014)supported by Aeronautical Science Foundation of China
文摘A new kind offl biomedical titanium alloy, Ti-35Nb-4Sn-6Mo-9Zr, composed of non-toxic elements Nb, Mo, Zr and Sn with lower elastic modulus and higher strength was designed based on d-electron alloy design theory and JMatPro software using orthogonal experiment. The microstructure and basic mechanical properties of designed alloy were investigated. The results show that the alloy is composed of single fl equiaxed grains after solution treatment at 800 ~C. Compared with Ti-6A1-4V, the mechanical properties of the designed alloy are more excellent： E=65 GPa, σb=834 MPa, σ0.2=802 MPa, and σ=11%, which is expected to become a promising new type implanted material. The research approach adopted can reduce the experimental time and cost effectively, and get the ideal experimental results.
文摘The coordination-dependent force fleld of TersofF for covalently bonded Si has been used tocalculate the cleavage force as a function of interplanar separation and hence to estimate surfaceenergies. This force field is already fitted to density functional results. The relation to bond-breaking and electron correlation will be emphasized. Finnis-Sinclair-type many-body potentialshave then been used to treat some d-electron metals. In particular, results for cleavage forcein bcc Fe will be presented, and also some calculations as two perfectly planar Fe surfaces arerubbed together' at different interplanar separations. Finally, lattice dynamical models for thesteady-state propagation of a screw dislocation, and then of a crack, will be used, again within abond-breaking type of force field. For the screw dislocation propagation. a solitary wave equationis shown to follow in the 'almost continuum' limit. Energy radiated by phonons as the dislocationmoves can thereby be calculated.
基金supported by the National Key R&D Project(2022YFA1503900)the National Natural Science Foundation of China(22363001,22479032 and 22250710677)+1 种基金the NSFC Center for SingleAtom Catalysis(22388102)the Natural Science Special Foundation of Guizhou University(202140)。
文摘Electrocatalytic CO_(2) reduction reaction(CO_(2)RR)to high-value-added products is a crucial approach for promoting carbon recycling and mitigating energy challenges.Here,extensive theoretical screenings were conducted on the nitrogen-doped graphene-supported heteronuclear dual-atom catalysts(DACs)M_(1)/M_(2)-NC(M=V,Cr,Mn,Fe,Co,Ni,and Cu)for CO_(2)RR using density functional theory(DFT)calculations.The calculations indicate that Mn/Cu-NC exhibits superior catalytic activity and selectivity for the CO_(2)RR to HCOOH with a limiting potential as low as−0.15 V.The superior performance is attributed to the strong d-electron coupling between Mn and Cu dual atoms in Mn/Cu-NC,which results in an upward shift of the d-band center of the Mn single atom closer to the Fermi level.Moreover,the adsorption of the key intermediate*OCHO on the Mn single atom was further enhanced,thereby reducing the limiting potential and improving the catalytic performance for CO_(2)RR.This work offers a comprehensive theoretical insight into the catalytic mechanism of the novel Mn/Cu-NC DAC for CO_(2)RR and establishes a critical descriptor of d-band center of the catalytic active center to determine the catalytic activity of DACs for CO_(2)RR,thereby providing guidance for the future design and fabrication of graphene-based metal DACs for CO_(2)RR.
