Photosynthesis in nature has been deemed as the most significant biochemical reaction,which maintains a relatively stable content of O_(2) and CO_(2) in the atmosphere.Herein,for a deeper comprehension of natural phot...Photosynthesis in nature has been deemed as the most significant biochemical reaction,which maintains a relatively stable content of O_(2) and CO_(2) in the atmosphere.Herein,for a deeper comprehension of natural photosynthesis,an artificial photosynthesis model reaction of photochemical CO_(2) to CO conversion(CO_(2)+2 H^(+)+2e^(-)→CO+H_(2)O)catalyzed by a homogeneous hexanuclear ring cobalt complex{K_(2)[CoO_(3)PCH_(2)N(CH_(2)CO_(2))_(2)]}_(6)(Co6 complex)is developed.Using the[Ru(bpy)_(3)]^(2+)as a photosensitizer and TEOA as a sacrificial electron donor,an optimal turnover frequency of 503.3 h^(‒1) and an apparent quantum efficiency of 0.81%are obtained.The good photocatalytic CO_(2) reduction performance is attributed to the efficient electron transfer between Co6 complex and[Ru(bpy)_(3)]^(2+),which boosts the photogenerated carriers separation of the photosensitizer.It is confirmed by the j‐V curves,light‐assisted UV‐vis curves,steady‐state photoluminescence spectra and real‐time laser flash photolysis experiments.In addition,the proposed catalytic mechanism for CO_(2) reduction reaction catalyzed by the Co6 complex is explored by the potassium thiocyanate poison experiment,Pourbaix diagram and density functional theory calculations.展开更多
The mechanism of addition of separate atoms to a growing center is considered with application of model of a pair interpenetration of atoms. Features of geometrical model are related with the electronic structure of a...The mechanism of addition of separate atoms to a growing center is considered with application of model of a pair interpenetration of atoms. Features of geometrical model are related with the electronic structure of atoms and the Pauli＇s exclusion principle. The forces providing self-organization of atoms in the bulk of a condensed substance are shown. The calculated interatomic distances in graphite and alloys of gold with silver coincide with those known from experiments with accuracy of 0.1%.展开更多
This paper present electrical networks, with topological modelisations, generalized cross talked functions implemented in a Kron＇s formalism; Coupling functions are called chords and give a powerful extension to the ...This paper present electrical networks, with topological modelisations, generalized cross talked functions implemented in a Kron＇s formalism; Coupling functions are called chords and give a powerful extension to the method. Applied in electromagnetic compatibility, it has proven its efficiency in time computation and accuracy. The paper review the Kron＇s formalism, a mathematical modelisation of currents by tensorial analysis and topologie, the string principles, and an application, at the end, we propose power-chopper modeling.展开更多
High-entropy ceramics(HECs) are gaining significant interest due to their huge composition space, unique microstructure, and adjustable properties. Previously reported studies focus mainly on HECs with the multi-catio...High-entropy ceramics(HECs) are gaining significant interest due to their huge composition space, unique microstructure, and adjustable properties. Previously reported studies focus mainly on HECs with the multi-cationic structure, while HECs with more than one anion are rarely studied. Herein we reported a new class of HECs, namely highentropy alumino-silicides(Mo0.25Nb0.25Ta0.25V0.25)(Al0.5Si0.5)2(HEAS-1) with multi-cationic and-anionic structure. The formation possibility of HEAS-1 was first theoretically analyzed from the aspects of thermodynamics and lattice size difference based on the first-principles calculations and then the HEAS-1 were successfully synthesized by the solid-state reaction at 1573K. The as-synthesized HEAS-1 exhibited good single-crystal hexagonal structure of metal alumino-silicides and simultaneously possessed high compositional uniformity.This study not only enriches the categories of HECs but also will open up a new research field on HECs with multi-cationic and-anionic structure.展开更多
In this paper,a microscopic phase-field model was used to investigate the effect of the oriented diffusion channel and the phases' effect mechanism for the Ni75Al6.0V19.0 alloy during a phase transformation proces...In this paper,a microscopic phase-field model was used to investigate the effect of the oriented diffusion channel and the phases' effect mechanism for the Ni75Al6.0V19.0 alloy during a phase transformation process.A diffusion channel of V was formed in the [100] direction.The oriented growth of DO22 in this direction,when an elastic misfit stress field existed,forced Al to form a diffusion channel next to DO22,resulting in L12-oriented growth.With an increase in stress,the oriented growth increased initially and then decreased.At a higher stress,the average values of the occupation probability for V atoms became constant later while Al atoms earlier.展开更多
Ramping a physical parameter is one of the most common experimental protocols in studying a quantum system, and ramping dynamics has been widely used in preparing a quantum state and probing physical properties. Here,...Ramping a physical parameter is one of the most common experimental protocols in studying a quantum system, and ramping dynamics has been widely used in preparing a quantum state and probing physical properties. Here, we present a novel method of probing quantum many-body correlation by ramping dynamics. We ramp a Hamiltonian parameter to the same target value from different initial values and with different velocities, and we show that the first-order correction on the finite ramping velocity is universal and path-independent, revealing a novel quantum many-body correlation function of the equilibrium phases at the target values. We term this method as the non-adiabatic linear response since this is the leading order correction beyond the adiabatic limit. We demonstrate this method experimentally by studying the Bose-Hubbard model with ultracold atoms in three-dimensional optical lattices.Unlike the conventional linear response that reveals whether the quasi-particle dispersion of a quantum phase is gapped or gapless, this probe is more sensitive to whether the quasi-particle lifetime is long enough such that the quantum phase possesses a well-defined quasi-particle description. In the BoseHubbard model, this non-adiabatic linear response is significant in the quantum critical regime where well-defined quasi-particles are absent. And in contrast, this response is vanishingly small in both superfluid and Mott insulators which possess well-defined quasi-particles. Because our proposal uses the most common experimental protocol, we envision that our method can find broad applications in probing various quantum systems.展开更多
文摘Photosynthesis in nature has been deemed as the most significant biochemical reaction,which maintains a relatively stable content of O_(2) and CO_(2) in the atmosphere.Herein,for a deeper comprehension of natural photosynthesis,an artificial photosynthesis model reaction of photochemical CO_(2) to CO conversion(CO_(2)+2 H^(+)+2e^(-)→CO+H_(2)O)catalyzed by a homogeneous hexanuclear ring cobalt complex{K_(2)[CoO_(3)PCH_(2)N(CH_(2)CO_(2))_(2)]}_(6)(Co6 complex)is developed.Using the[Ru(bpy)_(3)]^(2+)as a photosensitizer and TEOA as a sacrificial electron donor,an optimal turnover frequency of 503.3 h^(‒1) and an apparent quantum efficiency of 0.81%are obtained.The good photocatalytic CO_(2) reduction performance is attributed to the efficient electron transfer between Co6 complex and[Ru(bpy)_(3)]^(2+),which boosts the photogenerated carriers separation of the photosensitizer.It is confirmed by the j‐V curves,light‐assisted UV‐vis curves,steady‐state photoluminescence spectra and real‐time laser flash photolysis experiments.In addition,the proposed catalytic mechanism for CO_(2) reduction reaction catalyzed by the Co6 complex is explored by the potassium thiocyanate poison experiment,Pourbaix diagram and density functional theory calculations.
文摘The mechanism of addition of separate atoms to a growing center is considered with application of model of a pair interpenetration of atoms. Features of geometrical model are related with the electronic structure of atoms and the Pauli＇s exclusion principle. The forces providing self-organization of atoms in the bulk of a condensed substance are shown. The calculated interatomic distances in graphite and alloys of gold with silver coincide with those known from experiments with accuracy of 0.1%.
文摘This paper present electrical networks, with topological modelisations, generalized cross talked functions implemented in a Kron＇s formalism; Coupling functions are called chords and give a powerful extension to the method. Applied in electromagnetic compatibility, it has proven its efficiency in time computation and accuracy. The paper review the Kron＇s formalism, a mathematical modelisation of currents by tensorial analysis and topologie, the string principles, and an application, at the end, we propose power-chopper modeling.
基金supported by the National Key Research and Development Program of China (2017YFB0703200)Young Elite Scientists Sponsorship Program by China Association for Science and Technology (2017QNRC001)the National Natural Science Foundation of China (51802100 and 51972116)
文摘High-entropy ceramics(HECs) are gaining significant interest due to their huge composition space, unique microstructure, and adjustable properties. Previously reported studies focus mainly on HECs with the multi-cationic structure, while HECs with more than one anion are rarely studied. Herein we reported a new class of HECs, namely highentropy alumino-silicides(Mo0.25Nb0.25Ta0.25V0.25)(Al0.5Si0.5)2(HEAS-1) with multi-cationic and-anionic structure. The formation possibility of HEAS-1 was first theoretically analyzed from the aspects of thermodynamics and lattice size difference based on the first-principles calculations and then the HEAS-1 were successfully synthesized by the solid-state reaction at 1573K. The as-synthesized HEAS-1 exhibited good single-crystal hexagonal structure of metal alumino-silicides and simultaneously possessed high compositional uniformity.This study not only enriches the categories of HECs but also will open up a new research field on HECs with multi-cationic and-anionic structure.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51075335, 10902086, 50875217)the NPU Foundation for Fundamental Research (Grant No. JC201005)the Doctorate Foundation of Northwestern Polytechnical University (Grant No.CX201007)
文摘In this paper,a microscopic phase-field model was used to investigate the effect of the oriented diffusion channel and the phases' effect mechanism for the Ni75Al6.0V19.0 alloy during a phase transformation process.A diffusion channel of V was formed in the [100] direction.The oriented growth of DO22 in this direction,when an elastic misfit stress field existed,forced Al to form a diffusion channel next to DO22,resulting in L12-oriented growth.With an increase in stress,the oriented growth increased initially and then decreased.At a higher stress,the average values of the occupation probability for V atoms became constant later while Al atoms earlier.
基金supported by Beijing Outstanding Young Scholar Programthe National Key Research and Development Program of China (2021YFA0718303, 2021YFA1400904, and 2016YFA0301501)+1 种基金the National Natural Science Foundation of China (91736208, 11974202, 61975092, 11920101004,61727819, 11934002, 11734010, and 92165203)the XPLORER Prize。
文摘Ramping a physical parameter is one of the most common experimental protocols in studying a quantum system, and ramping dynamics has been widely used in preparing a quantum state and probing physical properties. Here, we present a novel method of probing quantum many-body correlation by ramping dynamics. We ramp a Hamiltonian parameter to the same target value from different initial values and with different velocities, and we show that the first-order correction on the finite ramping velocity is universal and path-independent, revealing a novel quantum many-body correlation function of the equilibrium phases at the target values. We term this method as the non-adiabatic linear response since this is the leading order correction beyond the adiabatic limit. We demonstrate this method experimentally by studying the Bose-Hubbard model with ultracold atoms in three-dimensional optical lattices.Unlike the conventional linear response that reveals whether the quasi-particle dispersion of a quantum phase is gapped or gapless, this probe is more sensitive to whether the quasi-particle lifetime is long enough such that the quantum phase possesses a well-defined quasi-particle description. In the BoseHubbard model, this non-adiabatic linear response is significant in the quantum critical regime where well-defined quasi-particles are absent. And in contrast, this response is vanishingly small in both superfluid and Mott insulators which possess well-defined quasi-particles. Because our proposal uses the most common experimental protocol, we envision that our method can find broad applications in probing various quantum systems.
