In this paper, the integrable classical case of the Hydrogen atom subjected to three static external fields is investigated. The structuring and evolution of the real phase space are explored. The bifurcation diagram ...In this paper, the integrable classical case of the Hydrogen atom subjected to three static external fields is investigated. The structuring and evolution of the real phase space are explored. The bifurcation diagram is found and the bifurcations of solutions are discussed. The periodic solutions and their associated periods for singular common-level sets of the first integrals of motion are explicitly described. Numerical investigations are performed for the integrable case by means of Poincaré surfaces of section and comparing them with nearby living nonintegrable solutions, all generic bifurcations that change the structure of the phase space are illustrated;the problem can exhibit regularity-chaos transition over a range of control parameters of system.展开更多
Developing highly active and selective catalysts for the hydrogenation of nitroarenes,an environmentally benign process to produce industrially important aniline intermediates,is highly desirable but very challenging....Developing highly active and selective catalysts for the hydrogenation of nitroarenes,an environmentally benign process to produce industrially important aniline intermediates,is highly desirable but very challenging.Pd catalysts are generally recognized as active but nonselective catalysts for this important reaction.Here,we report an effective strategy to greatly improve the selectivity of Pd catalysts based on the reactive metal–support interaction.展开更多
The new potential model of interlayer intermolecular interaction was proposed to represent“ABAB”stacking of graphite.The bombardment of hydrogen atoms on the graphite surface was investigated using molecular dynamic...The new potential model of interlayer intermolecular interaction was proposed to represent“ABAB”stacking of graphite.The bombardment of hydrogen atoms on the graphite surface was investigated using molecular dynamics simulation.Before the first graphene fromthe surface side was broken,the hydrogen atoms caused the following processes.In the case of the incident energy of 5 eV,many hydrogen atoms were adsorbed on the front of the first graphite.In the case of the incident energy of 15 eV,almost all hydrogen atoms were reflected by the first graphene.In the case of the incident energy of 30 eV,the hydrogen atoms were adsorbed between the first and second graphenes.The radial distribution function and the animation of the MD simulation demonstrated that the graphenes were peeled off one by one,which is called graphite peeling.One C2H2 was generated in such chemical sputtering.But the other yieldedmolecules often had chain structures terminated by the hydrogen atoms.The erosion yield increased linearly with time.展开更多
The effective utilization of solar energy for hydrogen production requires an abundant supply of thermodynamically active photo-electrons;however,the photocatalysts are generally impeded by insufficient light absorpti...The effective utilization of solar energy for hydrogen production requires an abundant supply of thermodynamically active photo-electrons;however,the photocatalysts are generally impeded by insufficient light absorption and fast photocarrier recombination.Here,we report a multiple-regulated strategy to capture photons and boost photocarrier dynamics by devel-oping a broadband photocatalyst composed of defect engineered g-C_(3)N_(4)(DCN)and upconversion NaYF4:Yb^(3+),Tm^(3+)(NYF)nanocrystals.Through a precise defect engineering,the S dopants and C vacancies jointly render DCN with defect states to effectively extend the visible light absorption to 590 nm and boost photocarrier separation via a moderate electron-trapping ability,thus facilitating the subsequent re-absorption and utilization of upconverted photons/electrons.Importantly,we found a promoted interfacial charge polarization between DCN and NYF has also been achieved mainly due to Y-N interaction,which further favors the upconverted excited energy transfer from NYF onto DCN as verified both theoretically and experimentally.With a 3D architecture,the NYF@DCN catalyst exhibits a superior solar H2 evolution rate among the reported upconversion-based system,which is 19.3 and 1.5 fold higher than bulk material and DCN,respectively.This work provides an innovative strategy to boost solar utilization by using defect engineering and building up interaction between hetero-materials.展开更多
<p align="justify"> <span style="font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">In this work, we extend our work on the Heisenberg model of the ...<p align="justify"> <span style="font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">In this work, we extend our work on the Heisenberg model of the neutron formulated as a dwarf hydrogen-like atom under the influence of the More General Exponential Screened Coulomb Potential (MGESCP) to show that an atomic nucleus may possess a molecular structure made up of atoms bonding together by a potential used to describe the strong force associated with a generalised Yukawa MGESCP potential. We show that the neutrons and protons are arranged into narrow lattices therefore they may fold to form three-dimensional shells by bonding similar to hydrogen bonding. In particular, the nucleons may form stable structures such as that of fullerenes in which the vertices are occupied by the nucleons which are simply just protons. For example, a nucleus with a total number of 60 nucleons may arrange itself into the topological structure of a buckminsterfullerene. We also apply </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">Schr</span></span><span style="font-family:;"><span style="font-family:;font-size:12px;"></span><span style="text-align:left;widows:2;text-transform:none;background-color:#ffffff;font-style:normal;text-indent:0px;display:inline !important;font-family:Verdana;white-space:normal;orphans:2;float:none;letter-spacing:normal;font-size:12px;font-weight:400;word-spacing:0px;font-variant-ligatures:normal;font-variant-caps:normal;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;">ö</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">dinger</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;"> wave equation with central field approximation to describe the quantum dynamics of nuclei of atomic atoms that now possess the physical structure of a dwarf molecular ion.</span></span> </p>展开更多
The dynamical properties of Rydberg hydrogen atom near a metal surface are presented by using the methods of phase space analysis and closed orbit theory. Transforming the coordinates of the Hamiltonian, we find that ...The dynamical properties of Rydberg hydrogen atom near a metal surface are presented by using the methods of phase space analysis and closed orbit theory. Transforming the coordinates of the Hamiltonian, we find that the phase space of the system is divided into vibrational and rotational region. Both the Poincaré surface of section and the closed orbit theory verify the same conclusion clearly. In this paper we choose the atomic principal quantum number as n = 20. The dynamical character of the exited hydrogen atom depends sensitively on the atom-surface distance d. When d is sufficiently large, the atom-surface potential can be expressed by the traditional van der Waals force and the system is integrable. When d becomes smaller, there exists a critical value dc. For d > dc, the system is near-integrable and the motion is regular. While chaotic motion appears for d < dc, and the system tends to be non-integrable. The trajectories become unstable and the electron might be captured onto the metal surface.展开更多
基金国家自然科学基金(22072172,22202227)国家杰出青年科学基金(21825204)+2 种基金中国科学院青年创新促进会(Y2021056)榆林学院与大连清洁能源国家实验室合作基金(YLU-DNL Fund 2022007)山西省科技创新团队专项资金(202304051001007)资助。
文摘In this paper, the integrable classical case of the Hydrogen atom subjected to three static external fields is investigated. The structuring and evolution of the real phase space are explored. The bifurcation diagram is found and the bifurcations of solutions are discussed. The periodic solutions and their associated periods for singular common-level sets of the first integrals of motion are explicitly described. Numerical investigations are performed for the integrable case by means of Poincaré surfaces of section and comparing them with nearby living nonintegrable solutions, all generic bifurcations that change the structure of the phase space are illustrated;the problem can exhibit regularity-chaos transition over a range of control parameters of system.
基金funding support from the National Natural Science Foundation of China(grant nos.U1932213,21431006,51732011,and 21761132008)the Foundation for Innovative Research Groups of the National Natural Sci-ence Foundationof China(grant no.21521001)+4 种基金and the Key Research Program of Frontier Sciences,CAS(grant no.QYZDJ-SSW-SLH036).H.W.L.is thankful for the support by the National Key Research and Development Program of China(no.2018YFA0702001)and the Fundamental Re-search Funds for the Central Universities(no.WK206-0190103).Z.Y.W.acknowledges the funding support from the National Natural Science Foundation of China(grant no.21703229)C.Q.H acknowledges the funding support from the Zhejiang Provincial Natural Science Foundation of Chi-na(grant no.LQ20B030008).W.X.L acknowledges the funding support from the National Natural Science Foun-dation of China(grant nos.91645202 and 91945302)the Key Research Programof Frontier Sciences,CAS(grantno.QYZDJ-SSW-SLH054)and the National Key Research and Development Program of China(grant nos.2018YFA-0208603 and 2017YFB0602205)partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.
文摘Developing highly active and selective catalysts for the hydrogenation of nitroarenes,an environmentally benign process to produce industrially important aniline intermediates,is highly desirable but very challenging.Pd catalysts are generally recognized as active but nonselective catalysts for this important reaction.Here,we report an effective strategy to greatly improve the selectivity of Pd catalysts based on the reactive metal–support interaction.
基金This work was supported in part by a Grand-in Aid for Ex-ploratory Research(C),2007,No.17540384 from the Ministry of Education,Culture,Sports,Science and TechnologyThis work was also supported by National Institutes of Natural Sciences undertaking for Forming Bases for Interdisciplinary and Interna-tional Research through Cooperation Across Fields of Study,and Collaborative Research Programs(No.NIFS06KDAT012,No.NIFS06KTAT029,No.NIFS07USNN002 and No.NIFS07KEIN0091).
文摘The new potential model of interlayer intermolecular interaction was proposed to represent“ABAB”stacking of graphite.The bombardment of hydrogen atoms on the graphite surface was investigated using molecular dynamics simulation.Before the first graphene fromthe surface side was broken,the hydrogen atoms caused the following processes.In the case of the incident energy of 5 eV,many hydrogen atoms were adsorbed on the front of the first graphite.In the case of the incident energy of 15 eV,almost all hydrogen atoms were reflected by the first graphene.In the case of the incident energy of 30 eV,the hydrogen atoms were adsorbed between the first and second graphenes.The radial distribution function and the animation of the MD simulation demonstrated that the graphenes were peeled off one by one,which is called graphite peeling.One C2H2 was generated in such chemical sputtering.But the other yieldedmolecules often had chain structures terminated by the hydrogen atoms.The erosion yield increased linearly with time.
基金support provided by the ARC through the ARC DP200101249 project.J.Feng would like to thank the computational resources provided by the High-Performance Computing Center of Qufu Normal University.D.Wang would like to acknowledge the National Natural Science Foundation of China(21903048,21971244,51932001,21931012,21590795)and National Key R&D Program of China(2018YFA0703504,2021YFB3802600).
文摘The effective utilization of solar energy for hydrogen production requires an abundant supply of thermodynamically active photo-electrons;however,the photocatalysts are generally impeded by insufficient light absorption and fast photocarrier recombination.Here,we report a multiple-regulated strategy to capture photons and boost photocarrier dynamics by devel-oping a broadband photocatalyst composed of defect engineered g-C_(3)N_(4)(DCN)and upconversion NaYF4:Yb^(3+),Tm^(3+)(NYF)nanocrystals.Through a precise defect engineering,the S dopants and C vacancies jointly render DCN with defect states to effectively extend the visible light absorption to 590 nm and boost photocarrier separation via a moderate electron-trapping ability,thus facilitating the subsequent re-absorption and utilization of upconverted photons/electrons.Importantly,we found a promoted interfacial charge polarization between DCN and NYF has also been achieved mainly due to Y-N interaction,which further favors the upconverted excited energy transfer from NYF onto DCN as verified both theoretically and experimentally.With a 3D architecture,the NYF@DCN catalyst exhibits a superior solar H2 evolution rate among the reported upconversion-based system,which is 19.3 and 1.5 fold higher than bulk material and DCN,respectively.This work provides an innovative strategy to boost solar utilization by using defect engineering and building up interaction between hetero-materials.
文摘<p align="justify"> <span style="font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">In this work, we extend our work on the Heisenberg model of the neutron formulated as a dwarf hydrogen-like atom under the influence of the More General Exponential Screened Coulomb Potential (MGESCP) to show that an atomic nucleus may possess a molecular structure made up of atoms bonding together by a potential used to describe the strong force associated with a generalised Yukawa MGESCP potential. We show that the neutrons and protons are arranged into narrow lattices therefore they may fold to form three-dimensional shells by bonding similar to hydrogen bonding. In particular, the nucleons may form stable structures such as that of fullerenes in which the vertices are occupied by the nucleons which are simply just protons. For example, a nucleus with a total number of 60 nucleons may arrange itself into the topological structure of a buckminsterfullerene. We also apply </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">Schr</span></span><span style="font-family:;"><span style="font-family:;font-size:12px;"></span><span style="text-align:left;widows:2;text-transform:none;background-color:#ffffff;font-style:normal;text-indent:0px;display:inline !important;font-family:Verdana;white-space:normal;orphans:2;float:none;letter-spacing:normal;font-size:12px;font-weight:400;word-spacing:0px;font-variant-ligatures:normal;font-variant-caps:normal;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;">ö</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">dinger</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;"> wave equation with central field approximation to describe the quantum dynamics of nuclei of atomic atoms that now possess the physical structure of a dwarf molecular ion.</span></span> </p>
基金supported by the National Natural Science Foundation of China(Grant Nos.10374061 and 90403028).
文摘The dynamical properties of Rydberg hydrogen atom near a metal surface are presented by using the methods of phase space analysis and closed orbit theory. Transforming the coordinates of the Hamiltonian, we find that the phase space of the system is divided into vibrational and rotational region. Both the Poincaré surface of section and the closed orbit theory verify the same conclusion clearly. In this paper we choose the atomic principal quantum number as n = 20. The dynamical character of the exited hydrogen atom depends sensitively on the atom-surface distance d. When d is sufficiently large, the atom-surface potential can be expressed by the traditional van der Waals force and the system is integrable. When d becomes smaller, there exists a critical value dc. For d > dc, the system is near-integrable and the motion is regular. While chaotic motion appears for d < dc, and the system tends to be non-integrable. The trajectories become unstable and the electron might be captured onto the metal surface.
