Transition metal selenides as sodium-ion hybrid capacitor(SIHC)anodes still suffer from amorphization difficulties and capacity degradation triggered by polyselenide dissolution.Herein,an atomistic amorphous strategy ...Transition metal selenides as sodium-ion hybrid capacitor(SIHC)anodes still suffer from amorphization difficulties and capacity degradation triggered by polyselenide dissolution.Herein,an atomistic amorphous strategy is proposed to construct adjacent Nb-Nb diatomic pairs with Se/O-coordination(Se4-Nb2-O2)in N-doped carbon-confined amorphous selenide clusters(a-Nb-Se/O@NC).Synergistic carbon confinement and hydrothermal oxygenation induce amorphization of Nb–Se bonds,eliminating crystalline rigidity while creating isotropic dual-ion transport channels and high-density active sites enriched with dangling bonds,thereby enhancing structural integrity and Na+storage capacity.The unique Se/O-coordinated Nb-Nb diatomic configuration establishes an electron-delocalized system,where the low electronegativity of Se counterbalances electron withdrawal from coordinated O at Nb centers.These strengthen d-p orbital hybridization,reduce Na+adsorption energy,and optimize charge transfer pathways and reaction kinetics in the amorphous clusters.Electrochemical tests reveal that the a-Nb-Se/O@NC anode delivers a high reversible capacity of 312.57 mAh g^(−1)and exceptional cyclic stability(103%capacity retention)after 5000 cycles at 10.0 A g^(−1).Assembled SIHCs achieve outstanding energy/power densities(207.1 Wh kg^(−1)/18966 W kg^(−1)),surpassing most amorphous and crystalline counterparts.This work provides methodological insights for the design of electrodes in high-power storage devices through atomic modulation and electronic optimization of amorphous selenides.展开更多
The adjacent matrix method for identifying isomorphism to planar kinematic chain with multiple joints and higher pairs is presented. The topological invariants of the planar kinematic chain can be calculated and compa...The adjacent matrix method for identifying isomorphism to planar kinematic chain with multiple joints and higher pairs is presented. The topological invariants of the planar kinematic chain can be calculated and compared by adjacent matrix. The quantity of calculation can be reduced effectively using the several divisions of bars and the reconfiguration of the adjacent matrix. As two structural characteristics of adjacent matrix, the number of division and division code are presented. It can be identified that two kinematic chains are isomorphic or not by comparing the structural characteristics of their adjacent matrixes using a method called matching row-to-row. This method may be applied to the planar linkage chain too. So, the methods of identifying isomorphism are unified in the planar kinematic chain that has or hasn＇t higher pairs with or without multiple joints. And it has some characters such as visual, simple and convenient for processing by computer, and so on.展开更多
Single-atom catalysts(SACs)challenge conventional multi-site catalysis by enabling oxidative processes like H_(2)and CO oxidation.However,we herein present that the completely isolated SACs are inactive,while spatiall...Single-atom catalysts(SACs)challenge conventional multi-site catalysis by enabling oxidative processes like H_(2)and CO oxidation.However,we herein present that the completely isolated SACs are inactive,while spatially adjacent single-atom pairs(interatomic distance<4Å)work cooperatively as the true active sites.Rh atomic densities were precisely tuned between 0.1 wt%–17.5 wt%via graphene quantum dots confinement.Mathematical modeling quantifies the scaling of active pairs versus electrochemical performance,rationalizing activity dependence on atomic proximity.^(18)O isotope labeling and in situ synchrotron infrared spectroscopy analyses identified a new reaction mechanism,with water bifunctional dissociation enabled on sub-4ÅRh pairs,and acts as the rate-determining step towards both CO and H_(2)oxidation.While H_(2)O enters the COOR process as a reactant and enters the HOR process as a molecular catalyst.Our findings redefine bifunctional catalysis,merging single-atom precision with nanoparticle-like cooperativity for efficient energy conversion systems.展开更多
Conversation analysis （CA） is an integral part of the study of language in communication, in which preference organization is an important topic for pragmatic research. This paper makes a study of preferred and disp...Conversation analysis （CA） is an integral part of the study of language in communication, in which preference organization is an important topic for pragmatic research. This paper makes a study of preferred and dispreferred second turns in naturally occurring interactions to show structurally expected or unexpected responses from the second parts of the adjacent pairs. The study is based on the analysis of examples of people＇s actual conversations. It is concluded that in actual conversations, the speaker may make a preferred or dispreferred answer in either marked or unmarked form according to the speaker＇s intention and conversation circumstances.展开更多
This paper discusses some key concepts in Conversation Analysis （CA）. Using the transcription symbols mainly developed by Jefferson （1974）, the author transcribes an authentic spoken text to further illustrate to ...This paper discusses some key concepts in Conversation Analysis （CA）. Using the transcription symbols mainly developed by Jefferson （1974）, the author transcribes an authentic spoken text to further illustrate to the reader how the analysis of the organization of a conversation or talk-in-action could be approached. The paper concludes that as key concepts in CA make possible the micro-level analysis of a conversation, classroom activities deriving from CA can highlight the micro-interactional level of a talk and teachers are able to explore language performance from a microanalytic perspective.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52573299)the Natural Science Foundation of Jiangxi province(No.20242BAB25223,20232BCJ23025,20232BCJ25040,20232BAB214024)the Special Funding Program for Graduate Student Innovation of Jiangxi Province(No.YC2024-S594).
文摘Transition metal selenides as sodium-ion hybrid capacitor(SIHC)anodes still suffer from amorphization difficulties and capacity degradation triggered by polyselenide dissolution.Herein,an atomistic amorphous strategy is proposed to construct adjacent Nb-Nb diatomic pairs with Se/O-coordination(Se4-Nb2-O2)in N-doped carbon-confined amorphous selenide clusters(a-Nb-Se/O@NC).Synergistic carbon confinement and hydrothermal oxygenation induce amorphization of Nb–Se bonds,eliminating crystalline rigidity while creating isotropic dual-ion transport channels and high-density active sites enriched with dangling bonds,thereby enhancing structural integrity and Na+storage capacity.The unique Se/O-coordinated Nb-Nb diatomic configuration establishes an electron-delocalized system,where the low electronegativity of Se counterbalances electron withdrawal from coordinated O at Nb centers.These strengthen d-p orbital hybridization,reduce Na+adsorption energy,and optimize charge transfer pathways and reaction kinetics in the amorphous clusters.Electrochemical tests reveal that the a-Nb-Se/O@NC anode delivers a high reversible capacity of 312.57 mAh g^(−1)and exceptional cyclic stability(103%capacity retention)after 5000 cycles at 10.0 A g^(−1).Assembled SIHCs achieve outstanding energy/power densities(207.1 Wh kg^(−1)/18966 W kg^(−1)),surpassing most amorphous and crystalline counterparts.This work provides methodological insights for the design of electrodes in high-power storage devices through atomic modulation and electronic optimization of amorphous selenides.
文摘The adjacent matrix method for identifying isomorphism to planar kinematic chain with multiple joints and higher pairs is presented. The topological invariants of the planar kinematic chain can be calculated and compared by adjacent matrix. The quantity of calculation can be reduced effectively using the several divisions of bars and the reconfiguration of the adjacent matrix. As two structural characteristics of adjacent matrix, the number of division and division code are presented. It can be identified that two kinematic chains are isomorphic or not by comparing the structural characteristics of their adjacent matrixes using a method called matching row-to-row. This method may be applied to the planar linkage chain too. So, the methods of identifying isomorphism are unified in the planar kinematic chain that has or hasn＇t higher pairs with or without multiple joints. And it has some characters such as visual, simple and convenient for processing by computer, and so on.
基金supported by the National Natural Science Foundation of China(U22A20396,22209168,and 12205301)the Natural Science Foundation of Anhui Province(2208085UD04)+2 种基金the Natural Science Foundation of Jiangsu Province(BG2024033)the Liaoning Binhai Laboratory(LBLF-2023-04),the Shandong Energy Institute(SEI U202307)the JSPS KAKENHI(JP25K01737 and JP24K23069).
文摘Single-atom catalysts(SACs)challenge conventional multi-site catalysis by enabling oxidative processes like H_(2)and CO oxidation.However,we herein present that the completely isolated SACs are inactive,while spatially adjacent single-atom pairs(interatomic distance<4Å)work cooperatively as the true active sites.Rh atomic densities were precisely tuned between 0.1 wt%–17.5 wt%via graphene quantum dots confinement.Mathematical modeling quantifies the scaling of active pairs versus electrochemical performance,rationalizing activity dependence on atomic proximity.^(18)O isotope labeling and in situ synchrotron infrared spectroscopy analyses identified a new reaction mechanism,with water bifunctional dissociation enabled on sub-4ÅRh pairs,and acts as the rate-determining step towards both CO and H_(2)oxidation.While H_(2)O enters the COOR process as a reactant and enters the HOR process as a molecular catalyst.Our findings redefine bifunctional catalysis,merging single-atom precision with nanoparticle-like cooperativity for efficient energy conversion systems.
文摘Conversation analysis （CA） is an integral part of the study of language in communication, in which preference organization is an important topic for pragmatic research. This paper makes a study of preferred and dispreferred second turns in naturally occurring interactions to show structurally expected or unexpected responses from the second parts of the adjacent pairs. The study is based on the analysis of examples of people＇s actual conversations. It is concluded that in actual conversations, the speaker may make a preferred or dispreferred answer in either marked or unmarked form according to the speaker＇s intention and conversation circumstances.
文摘This paper discusses some key concepts in Conversation Analysis （CA）. Using the transcription symbols mainly developed by Jefferson （1974）, the author transcribes an authentic spoken text to further illustrate to the reader how the analysis of the organization of a conversation or talk-in-action could be approached. The paper concludes that as key concepts in CA make possible the micro-level analysis of a conversation, classroom activities deriving from CA can highlight the micro-interactional level of a talk and teachers are able to explore language performance from a microanalytic perspective.
