A city is a complex giant system,in which landscape is a process,and emphasizes the regulation of social relationships in the process of creating landscape,rather than simply creating a kind of landscape.In response t...A city is a complex giant system,in which landscape is a process,and emphasizes the regulation of social relationships in the process of creating landscape,rather than simply creating a kind of landscape.In response to the slogan of high-quality development of China,communities,as the earliest developed but declining old areas in Chinese cities,are the focus of current urban renovation work.By studying the latest research theories in the process of community renewal,it is concluded that there is a close relationship between“community renewal”and“landscape justice”or“public participation”.Based on this,research related to community renewal and landscape justice were sorted out,and suggestions for future research focus were proposed.展开更多
Multi-metal porous crystalline materials(MPCM),integrating the functions of both multi-metal centres and porous crystalline materials(e.g.,metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)),are an ex...Multi-metal porous crystalline materials(MPCM),integrating the functions of both multi-metal centres and porous crystalline materials(e.g.,metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)),are an extended class of porous materials that have attracted much attention for a broad range of applications.Owing to the advantages of these materials,they generally display high porosity,multimetal active sites,well-tuned functions,and pre-designable structures,etc.,serving as desired platforms for the study of structure-property relationships.In view of the clean and sustainable target,a series of MPCM have been explored as electrocatalysts for electrocatalytic reactions like hydrogen evolution reaction,oxygen evolution reaction and electrocatalytic CO_(2)reduction reaction.Concerning the progress achieved for MPCM in electrocatalytic field during past years,this review will provide a brief introduction on the recent breakthrough of MPCM based electrocatalysts including their synthesis methods,structure design,component/morphology tuning,electrocatalytic property and structure-property relationship,etc.Besides,it will also conclude the current challenges and present perspectives for the MPCM based electrocatalysts,which might promote the development of porous crystalline materials in electrocatalysis and hope to provide new insights for scientists in related fields.展开更多
In this work,we proposed a method to enhance the magnetic properties of(Nd,Ce)-Fe-B magnets with Ce/TRE ratios below 25 wt%by introducing a moderate amount of La elements.The segregation behavior of La elements toward...In this work,we proposed a method to enhance the magnetic properties of(Nd,Ce)-Fe-B magnets with Ce/TRE ratios below 25 wt%by introducing a moderate amount of La elements.The segregation behavior of La elements towards grain boundaries(GBs)was utilized to optimize the GB phase structure.Incorporation of La atoms into the main phase induces lattice expansion,leading to an increased formation of Ce^(3+)ions with enhanced magnetic moments.Comparative analysis with the original magnet(La/Ce=0 wt%)demonstrates that the magnet with a La/Ce ratio of 10 wt%exhibits improvements of 0.3%in remanence,12.6%in coercivity,and 0.6%in maximum energy produ ct.These results underscore that the moderate addition of La elements enhances the fluidity of the rare earth-rich phase and optimizes the distribution of lamellar GB,consequently reinforcing the magnetic isolation effect.Furthermore,the promotion of the transformation from Ce^(4+)to Ce^(3+)ons contributes to the comprehensive enhancement of the magnetic properties.This research offers a novel strategy for fabricating high-performance and resource-e fficient sintered magnets based on LaCe alloys.展开更多
Metal phosphosulfides(MPS_(x)),especially BiPS_(4),have emerged as promising anode candidates for sodiumion batteries,distinguished by distinctive multinary redox chemistry,open tunnel-type structure,and high theoreti...Metal phosphosulfides(MPS_(x)),especially BiPS_(4),have emerged as promising anode candidates for sodiumion batteries,distinguished by distinctive multinary redox chemistry,open tunnel-type structure,and high theoretical capacity(>1000 m Ah g^(-1)).However,their practical implementation is fundamentally limited by polysulfide dissolution/shuttling and structural instability during prolonged cycling.Herein,we develop a groundbreaking two-stage metal-organic framework(MOF)-engineered compositing strategy through which Bi-MOF-derived BiPS_(4)/C pillars are robustly armored with conductive Ni-HHTP(HHTP=2,3,6,7,10,11-hexahydroxytriphenylene)nanorods.Density functional theory calculations reveal that this design achieves dual functionality:increased carrier density for enhanced charge transport dynamics and effective polysulfide adsorption to inhibit dissolution.The fabricated BiPS_(4)/C@Ni-HHTP composite delivers remarkable electrochemical properties,including high initial charge/discharge specific capacities of 1063.6/1181.3 mAh g^(-1)at 0.1 A g^(-1)and outstanding long-term stability with 99.2% capacity retention after 2000 cycles at 2 A g^(-1).Such superb performance stems from the perfect synergy of the inherent high-capacity redox behavior of BiPS_(4),the buffering effect of MOF-derived carbon,and the conductivity,adsorption sites and mechanical resilience of Ni-HHTP.This work establishes a new design paradigm for MPS_(x)materials,demonstrating how to simultaneously overcome conductivity limitations and shuttle effects in conversion-type electrodes.展开更多
The enhancement of coercivity in Nd-Fe-B sintered magnets modified by Pr_(58)Dy_(10)Cu_(32)alloy was investigated through scanning electron microscope(SEM)and in-situ magneto-optic Kerr effect(MOKE)microscopy.The modi...The enhancement of coercivity in Nd-Fe-B sintered magnets modified by Pr_(58)Dy_(10)Cu_(32)alloy was investigated through scanning electron microscope(SEM)and in-situ magneto-optic Kerr effect(MOKE)microscopy.The modification treatment resulted in the formation of a smooth and continuous weakly magnetic grain boundary layer and the(Nd,Pr,Dy)_(2)Fe_(14)B main phase with a high magnetocrystalline anisotropy field,leading to an increased coercivity of 23 kOe.MOKE observations revealed that the dynamic evolution of the maze domain area under an external magnetic field varied significantly between the original and modified magnets.Compared with the original magnets,the modified magnets exhibited a slower decrease in maze domain area during magnetization and a slower increase during reverse magnetization,contributing to the observed coercivity enhancement.展开更多
基金Sponsored by the Project of Research on Humanities and Social Sciences of Chongqing Education Commission(22SKGH161)Urban Management Scientific Research Project of Chongqing City(Chengguankezi 2024,No.34).
文摘A city is a complex giant system,in which landscape is a process,and emphasizes the regulation of social relationships in the process of creating landscape,rather than simply creating a kind of landscape.In response to the slogan of high-quality development of China,communities,as the earliest developed but declining old areas in Chinese cities,are the focus of current urban renovation work.By studying the latest research theories in the process of community renewal,it is concluded that there is a close relationship between“community renewal”and“landscape justice”or“public participation”.Based on this,research related to community renewal and landscape justice were sorted out,and suggestions for future research focus were proposed.
基金supported by the National Key R&D Program of China(No.2023YFA1507204)the National Natural Science Foundation of China(Nos.22171139,22225109,22309054,22071109,22371080,21775048)+2 种基金Natural Science Foundation of Guangdong Province(No.2023B1515020076)China Postdoctoral Science Foundation(No.2023M731154)China National Postdoctoral Program for Innovative Talents(No.BX20220116)。
文摘Multi-metal porous crystalline materials(MPCM),integrating the functions of both multi-metal centres and porous crystalline materials(e.g.,metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)),are an extended class of porous materials that have attracted much attention for a broad range of applications.Owing to the advantages of these materials,they generally display high porosity,multimetal active sites,well-tuned functions,and pre-designable structures,etc.,serving as desired platforms for the study of structure-property relationships.In view of the clean and sustainable target,a series of MPCM have been explored as electrocatalysts for electrocatalytic reactions like hydrogen evolution reaction,oxygen evolution reaction and electrocatalytic CO_(2)reduction reaction.Concerning the progress achieved for MPCM in electrocatalytic field during past years,this review will provide a brief introduction on the recent breakthrough of MPCM based electrocatalysts including their synthesis methods,structure design,component/morphology tuning,electrocatalytic property and structure-property relationship,etc.Besides,it will also conclude the current challenges and present perspectives for the MPCM based electrocatalysts,which might promote the development of porous crystalline materials in electrocatalysis and hope to provide new insights for scientists in related fields.
基金Project supported by the National Natural Science Foundation of China(52071004,52301228,51971005,52171168)the Program of Top Disciplines Construction in Beijing(PXM2019_014204_500031)the International Research Cooperation Seed Fund of Beijing University of Technology(2021B23)。
文摘In this work,we proposed a method to enhance the magnetic properties of(Nd,Ce)-Fe-B magnets with Ce/TRE ratios below 25 wt%by introducing a moderate amount of La elements.The segregation behavior of La elements towards grain boundaries(GBs)was utilized to optimize the GB phase structure.Incorporation of La atoms into the main phase induces lattice expansion,leading to an increased formation of Ce^(3+)ions with enhanced magnetic moments.Comparative analysis with the original magnet(La/Ce=0 wt%)demonstrates that the magnet with a La/Ce ratio of 10 wt%exhibits improvements of 0.3%in remanence,12.6%in coercivity,and 0.6%in maximum energy produ ct.These results underscore that the moderate addition of La elements enhances the fluidity of the rare earth-rich phase and optimizes the distribution of lamellar GB,consequently reinforcing the magnetic isolation effect.Furthermore,the promotion of the transformation from Ce^(4+)to Ce^(3+)ons contributes to the comprehensive enhancement of the magnetic properties.This research offers a novel strategy for fabricating high-performance and resource-e fficient sintered magnets based on LaCe alloys.
基金Financial supports from the National Natural Science Foundation of China(Grant Number:22265018)the Key Project of Natural Science Foundation of Jiangxi Province(Grant Number:20232ACB204010)+1 种基金the Graduate Innovative Special Fund Projects of Jiangxi Province(Grant Number:YC2024-B034)the Jiangxi Province Key Laboratory of Lithiumion Battery Materials and Application(Grant Number:2024SSY05202)are gratefully acknowledged。
文摘Metal phosphosulfides(MPS_(x)),especially BiPS_(4),have emerged as promising anode candidates for sodiumion batteries,distinguished by distinctive multinary redox chemistry,open tunnel-type structure,and high theoretical capacity(>1000 m Ah g^(-1)).However,their practical implementation is fundamentally limited by polysulfide dissolution/shuttling and structural instability during prolonged cycling.Herein,we develop a groundbreaking two-stage metal-organic framework(MOF)-engineered compositing strategy through which Bi-MOF-derived BiPS_(4)/C pillars are robustly armored with conductive Ni-HHTP(HHTP=2,3,6,7,10,11-hexahydroxytriphenylene)nanorods.Density functional theory calculations reveal that this design achieves dual functionality:increased carrier density for enhanced charge transport dynamics and effective polysulfide adsorption to inhibit dissolution.The fabricated BiPS_(4)/C@Ni-HHTP composite delivers remarkable electrochemical properties,including high initial charge/discharge specific capacities of 1063.6/1181.3 mAh g^(-1)at 0.1 A g^(-1)and outstanding long-term stability with 99.2% capacity retention after 2000 cycles at 2 A g^(-1).Such superb performance stems from the perfect synergy of the inherent high-capacity redox behavior of BiPS_(4),the buffering effect of MOF-derived carbon,and the conductivity,adsorption sites and mechanical resilience of Ni-HHTP.This work establishes a new design paradigm for MPS_(x)materials,demonstrating how to simultaneously overcome conductivity limitations and shuttle effects in conversion-type electrodes.
基金supported by the National Key Research and Development Program of China(Grant Nos.2021YFB3500300,2023YFB3507000,and 2023XYJG0001-01-03)the National Natural Science Foundation of China(Grant No.52171167)Inner Mongolia Northern Rare Earth Advanced Materials Technology Innovation Co.,Ltd.Project(Grant No.CXZX-B-202304-0004).
文摘The enhancement of coercivity in Nd-Fe-B sintered magnets modified by Pr_(58)Dy_(10)Cu_(32)alloy was investigated through scanning electron microscope(SEM)and in-situ magneto-optic Kerr effect(MOKE)microscopy.The modification treatment resulted in the formation of a smooth and continuous weakly magnetic grain boundary layer and the(Nd,Pr,Dy)_(2)Fe_(14)B main phase with a high magnetocrystalline anisotropy field,leading to an increased coercivity of 23 kOe.MOKE observations revealed that the dynamic evolution of the maze domain area under an external magnetic field varied significantly between the original and modified magnets.Compared with the original magnets,the modified magnets exhibited a slower decrease in maze domain area during magnetization and a slower increase during reverse magnetization,contributing to the observed coercivity enhancement.
