The relative spatial scale relationship of observers and ecosystem and their aesthetic dynamic interaction process are fundamental to evaluation and optimization of aesthetic ecosystem service(AES).A comprehensive and...The relative spatial scale relationship of observers and ecosystem and their aesthetic dynamic interaction process are fundamental to evaluation and optimization of aesthetic ecosystem service(AES).A comprehensive and efficient framework for the assessment of AES is lack in the integration of scale relationship and dynamic process.This study took 9 villages in 4 different developmental stages(traditional,folk,rapidly changed,newly built)in Honghe Hani Rice Terraces,a world heritage site,as the research object.From two scales,viewing from inside and outside,the bi-scale assessing framework was established,which includes the three components of interaction process,connection area(as precondition of interaction),quality(as result of interaction),and influencing factors of quality(elements’characteristics of villages).Among them,the connection areas were evaluated with visual and traffic accessibility along the route.The quality and influencing factors were evaluated through participatory preferences methods by expert group.The influencing factors include 9 characteristics,such as,space size,architecture layout,vegetation species richness,color diversity.The results suggested that villages with high AES quality and low accessibility need to be optimized,and the key influencing factors are space size,architecture layout,color harmony and surrounding sanitation.Therefore,the bi-scale assessing framework can provide important references for decision making and visual protection regulations on the villages.展开更多
A new heteropolyoxotungstate [（C2H4N2）4（P4Co3W4O28H6）（H2C2O4）]n with a three-dimensional framework was hydrothermally synthesized.The compound crystallizes in a tetragonal system,space group I41/a with a = 17.1...A new heteropolyoxotungstate [（C2H4N2）4（P4Co3W4O28H6）（H2C2O4）]n with a three-dimensional framework was hydrothermally synthesized.The compound crystallizes in a tetragonal system,space group I41/a with a = 17.1006（17）,b = 17.1006（7）,c = 10.7525（5）,V = 3144.2（2）3,Z = 4,Dc = 3.795 g·cm-3,F（000） = 3300,MoKα（λ = 0.71073 ）,μ = 16.460 mm-1,the final R = 0.0335 and wR = 0.0776.In the heteropolyoxotungstate,tungsten-oxygen octahedra are linked by sharing two cis-vertexes into an infinite helical chain extending along the c axis.Cobalt atoms in the octahedral geometry act as the linkers of these chains,forming a three-dimensional framework.The cobalt and phosphorus atoms in the tetrahedral geometry play a role in stabilizing the three-dimensional framework.Ethylenediamine molecules are polymerized into organic chains which locate in the interspaces of the framework in the way of interwinding with the W-O chains.展开更多
The evolution of the society and economy has stimulated the development of Knowledge Service(KS), making it an indispensable solution to address future challenges facing libraries and information institutions. However...The evolution of the society and economy has stimulated the development of Knowledge Service(KS), making it an indispensable solution to address future challenges facing libraries and information institutions. However at present, academic research on knowledge service is falling short and its definition is far from clear and complete. As such,this article proposes the Three-dimensional Framework Knowledge Service(TdFKS) for libraries and information institutions based on the knowledge value chain model. By making reliability analysis and mean value analysis of a questionnaire survey result, the article clarifies the structure of the three-dimensional framework and verifies the rationality of the TdFKS.展开更多
The Critical Discourse Analysis(CDA)is an interdisciplinary tool in various conditions,which aims to provide a better understanding of sociocultural aspects of texts and accounts of the production of internal structur...The Critical Discourse Analysis(CDA)is an interdisciplinary tool in various conditions,which aims to provide a better understanding of sociocultural aspects of texts and accounts of the production of internal structure,and overall organization of texts as well as to provide a critical dimension in its theoretical and descriptive accounts of texts.Since June last year,HK protests or HK violence have been frequently reported by worldwide media.In this paper,the author aims to find out how the HK protesters and the Mainland media describe the same event based on the three-dimensional framework of CDA.At last,the author concludes that the mainland media generally describe the event as violence and riot while the HK protesters define themselves as warriors striving for more freedom,justice and democracy.Besides,on this event,the Mainland media mainly accuses some western countries of interference into HK affairs,which is undoubtedly of China’s internal affairs,and the media give full support to the HK police in safeguarding the peace and stability of Hong Kong.But from the perspective of HK protesters,they firmly believe that they are using their actions to protect all the people of HK,and they are defending their values such as freedom,democracy and justice.These are two totally different systems of language,and the author also gives its potential reasons in the paper so as to offer some viewpoints in this aspect in combination with the CDA theory.展开更多
A novel Ni（II） coordination polymer [Ni（dtba）（4,4′-bpy）] （1, H2dtba = 2,2′-dithio- bisbenzoic acid, 4,4′-bpy = 4,4′-bipyridine） has been synthesized by H2dtba and Ni（CH3COO）2·4H2O with exo-bidentate...A novel Ni（II） coordination polymer [Ni（dtba）（4,4′-bpy）] （1, H2dtba = 2,2′-dithio- bisbenzoic acid, 4,4′-bpy = 4,4′-bipyridine） has been synthesized by H2dtba and Ni（CH3COO）2·4H2O with exo-bidentate rigid ligand 4,4′-bpy by using hydrothermal method, and its structure was determined by single-crystal X-ray diffraction. X-ray crystal structure analysis reveals that complex 1 crystallizes in monoclinic, space group Cc with a = 11.7624（9）, b = 18.7933（19）, c = 10.3071（11）, β = 97.6510（10）°, V = 2258.2（4）3, Z = 4, C24H16N2NiO4S2, Mr = 519.22, Dc = 1.527 g/cm3, μ = 1.079 mm-1 and F（000） = 1064. The structure was solved by direct methods and refined to R = 0.0434 and wR = 0.1000 for 3281 observed reflections （I 〉 2σ（I））. The coordination environment of Ni（II） is a distorted octahedron, and a three-dimensional structure was formed with the coordination effect of dtba2- and 4,4′-bpy ligands. The topological analysis reveals that the whole framework of 1 is a 2-nodal net of （52.6）（53.64.72.8） topology. The thermal stability and XRD pattern of 1 were also investigated展开更多
Covalent organic frameworks(COFs) are a class of crystalline porous organic materials with variable structures and fascinating properties. The intrinsic low conductivity impedes their widely application in optoelectro...Covalent organic frameworks(COFs) are a class of crystalline porous organic materials with variable structures and fascinating properties. The intrinsic low conductivity impedes their widely application in optoelectronic. Iodine doping is an effective way to enhance the electrical conductivity of COFs. Here, a novel 3D imine COF with lvt topology is synthesized from two different pentacene derivatives with the same core in the form of structural complementarity. DDHP-COF is a highly crystalline material featuring high surface area of 1679 m^(2)/g and excellent thermal stability up to 490 ℃. Upon doping with iodine, the electrical conductivity can reach as high as 1.5×10^(-2)S/m which is significantly enhanced over 6 orders of magnitude compared with the pristine COF.展开更多
Si materials are widely considered to be the next-generation anode to replace the current commercial graphite-based anode due to its high energy density.However,the large volume variation of silicon during(de)lithiati...Si materials are widely considered to be the next-generation anode to replace the current commercial graphite-based anode due to its high energy density.However,the large volume variation of silicon during(de)lithiation process leads to rapid capacity decay,hindering its commercial application.Although the various hollow structure designs of Si nanomaterials have improved their cycling stability in the laboratory,the high-pressure calendering process in the current industrial electrode preparation process might collapse the hollow structure and weaken the structural advantages of hollow silicon anode materials.In this work,a silicon carbon composite material(Si@3DC)in which Si nanoparticles were anchored on a three-dimensional carbon framework through carbon films was prepared by a simple proton exchange method.The three-dimensional carbon framework with multiple hierarchical pores of Si@3DC was compatible with the high-pressure calendering process,but also could provide expansion space for Si nanoparticles during the lithiation process,and ensure good electronic and ionic conductivity.The carbon film on the surface of Si nanoparticles promoted the formation of stable solid electrolyte interphase(SEI)films,ensuring the good cycle stability of Si@3DC.展开更多
Although metal–organic frameworks have been heavily tested as the anode materials for lithium-ion batteries(LIBs),the poorer conductivity,easy collapse of frameworks,and serious volume expansion limit their further a...Although metal–organic frameworks have been heavily tested as the anode materials for lithium-ion batteries(LIBs),the poorer conductivity,easy collapse of frameworks,and serious volume expansion limit their further application in LIBs.Herein,we report a facile approach to obtain MXene-encapsulated porous Ni-naphthalene dicarboxylic acid(Ni-NDC)nanosheets by hybridizing ultrathin Ti_(3)C_(2)MXene and three-dimensional(3D)Ni-NDC nanosheet aggregates.In the structure of Ni-NDC/MXene hybrids,the interlayer hydrogen-bond interaction between Ni-NDC and MXene can effectively increase the interlayer spacing and further inhibit the oxidation of pure MXene.Hence,the introduction of MXene(a conductive matrix)could further improve the conductivity of Ni-NDC,avoid self-agglomeration,and buffer the volume expansion of Ni-NDC nanosheets.Benefiting from the synergistic effects between Ni-NDC and MXene,Ni-NDC/MXene hybrid electrode exhibits a reversible discharge capacity(579.8 mA∙h∙g^(−1)at 100 mA∙g^(−1)after 100 cycles)and good long-term cycling performance(310 mA∙h∙g^(−1)at 1 A∙g^(−1)after 500 cycles).展开更多
Two reported three-dimensional covalent organic frameworks(3D-COFs),COF-300 and COF-301,which have hierarchical porous structures and large pore volumes,were synthesized and employed as host materials for lithium-sulf...Two reported three-dimensional covalent organic frameworks(3D-COFs),COF-300 and COF-301,which have hierarchical porous structures and large pore volumes,were synthesized and employed as host materials for lithium-sulfur batteries.Owing to possessing excellent porosities as well as abundant hydroxyl groups in the pore walls,COF-301 can not only trap lithium polysulfides(PSs)via physical adsorption inside the pores,but also capture PSs by chemical interactions to relieve the shuttle effect.Interestingly,it is the first time that 3D-COFs were utilized as host materials for lithium-sulfur batteries as well as hydroxyl groups were introduced into COFs for improving the battery performance.As a result,COF-301@S as cathode material could reserve the capacity of 411.6 mA·h·g^-1 after 500 cycles with only 0.081%fading per cycle at 0.5 C,exhibiting better battery performance compared with COF-300@S.This study not only expands the applications of 3D-COFs but also provides a new route for designing lithium-sulfur batteries.展开更多
The open-framework iron phosphate IIIII21.543FeFe(PO) was hydrothermally synthesized and characterized by elemental analysis, IR, EPR, XPS and single crystal X-ray diffraction analysis. The title compound crystallized...The open-framework iron phosphate IIIII21.543FeFe(PO) was hydrothermally synthesized and characterized by elemental analysis, IR, EPR, XPS and single crystal X-ray diffraction analysis. The title compound crystallized in the triclinic, space group P1with a=0.64724(4) nm, b=0.79651(6) nm, c=0.94229(5) nm, =104.447(2)? =108.919(4)? =101.741(4)? V=0.42302(5) nm3, Z=1 and R1 (wR2)=0.0307 (0.0793). Crystal data were collected on a Rigaku R-AXIS RAPID IP diffractometer with Mo K?(=0.071073 nm) at 293(2) K in the range of 2.43埃迹?7.46? The structure of 1 consists of 19 non-hydrogen atoms including three and a half crystallographically in-dependent Fe and three P atoms. Fe(1) connects its symmetrical Fe(1A) through bridging oxygen forming a dimer and the dimers are connected by Fe(4) forming an infinite staircase-like chain. Fe(2) and Fe(3) connect the infinite chains into a layer with bridging oxygen. Layers are interconnected via Fe(4) forming the six-membered and eight-membered channel systems.展开更多
基金funded by the National Natural Science Foundation of China(grant numbers 41761115,41271203)。
文摘The relative spatial scale relationship of observers and ecosystem and their aesthetic dynamic interaction process are fundamental to evaluation and optimization of aesthetic ecosystem service(AES).A comprehensive and efficient framework for the assessment of AES is lack in the integration of scale relationship and dynamic process.This study took 9 villages in 4 different developmental stages(traditional,folk,rapidly changed,newly built)in Honghe Hani Rice Terraces,a world heritage site,as the research object.From two scales,viewing from inside and outside,the bi-scale assessing framework was established,which includes the three components of interaction process,connection area(as precondition of interaction),quality(as result of interaction),and influencing factors of quality(elements’characteristics of villages).Among them,the connection areas were evaluated with visual and traffic accessibility along the route.The quality and influencing factors were evaluated through participatory preferences methods by expert group.The influencing factors include 9 characteristics,such as,space size,architecture layout,vegetation species richness,color diversity.The results suggested that villages with high AES quality and low accessibility need to be optimized,and the key influencing factors are space size,architecture layout,color harmony and surrounding sanitation.Therefore,the bi-scale assessing framework can provide important references for decision making and visual protection regulations on the villages.
基金supported by the Analysis and Testing Foundation of Northeast Normal University
文摘A new heteropolyoxotungstate [（C2H4N2）4（P4Co3W4O28H6）（H2C2O4）]n with a three-dimensional framework was hydrothermally synthesized.The compound crystallizes in a tetragonal system,space group I41/a with a = 17.1006（17）,b = 17.1006（7）,c = 10.7525（5）,V = 3144.2（2）3,Z = 4,Dc = 3.795 g·cm-3,F（000） = 3300,MoKα（λ = 0.71073 ）,μ = 16.460 mm-1,the final R = 0.0335 and wR = 0.0776.In the heteropolyoxotungstate,tungsten-oxygen octahedra are linked by sharing two cis-vertexes into an infinite helical chain extending along the c axis.Cobalt atoms in the octahedral geometry act as the linkers of these chains,forming a three-dimensional framework.The cobalt and phosphorus atoms in the tetrahedral geometry play a role in stabilizing the three-dimensional framework.Ethylenediamine molecules are polymerized into organic chains which locate in the interspaces of the framework in the way of interwinding with the W-O chains.
基金supported by the National Planning Office of Philosophy and Social Science(Grant No.06BTQ027)
文摘The evolution of the society and economy has stimulated the development of Knowledge Service(KS), making it an indispensable solution to address future challenges facing libraries and information institutions. However at present, academic research on knowledge service is falling short and its definition is far from clear and complete. As such,this article proposes the Three-dimensional Framework Knowledge Service(TdFKS) for libraries and information institutions based on the knowledge value chain model. By making reliability analysis and mean value analysis of a questionnaire survey result, the article clarifies the structure of the three-dimensional framework and verifies the rationality of the TdFKS.
文摘The Critical Discourse Analysis(CDA)is an interdisciplinary tool in various conditions,which aims to provide a better understanding of sociocultural aspects of texts and accounts of the production of internal structure,and overall organization of texts as well as to provide a critical dimension in its theoretical and descriptive accounts of texts.Since June last year,HK protests or HK violence have been frequently reported by worldwide media.In this paper,the author aims to find out how the HK protesters and the Mainland media describe the same event based on the three-dimensional framework of CDA.At last,the author concludes that the mainland media generally describe the event as violence and riot while the HK protesters define themselves as warriors striving for more freedom,justice and democracy.Besides,on this event,the Mainland media mainly accuses some western countries of interference into HK affairs,which is undoubtedly of China’s internal affairs,and the media give full support to the HK police in safeguarding the peace and stability of Hong Kong.But from the perspective of HK protesters,they firmly believe that they are using their actions to protect all the people of HK,and they are defending their values such as freedom,democracy and justice.These are two totally different systems of language,and the author also gives its potential reasons in the paper so as to offer some viewpoints in this aspect in combination with the CDA theory.
基金the National Natural Science Foundation of China (No. 20771006, 20901004 and 20801025)
文摘A novel Ni（II） coordination polymer [Ni（dtba）（4,4′-bpy）] （1, H2dtba = 2,2′-dithio- bisbenzoic acid, 4,4′-bpy = 4,4′-bipyridine） has been synthesized by H2dtba and Ni（CH3COO）2·4H2O with exo-bidentate rigid ligand 4,4′-bpy by using hydrothermal method, and its structure was determined by single-crystal X-ray diffraction. X-ray crystal structure analysis reveals that complex 1 crystallizes in monoclinic, space group Cc with a = 11.7624（9）, b = 18.7933（19）, c = 10.3071（11）, β = 97.6510（10）°, V = 2258.2（4）3, Z = 4, C24H16N2NiO4S2, Mr = 519.22, Dc = 1.527 g/cm3, μ = 1.079 mm-1 and F（000） = 1064. The structure was solved by direct methods and refined to R = 0.0434 and wR = 0.1000 for 3281 observed reflections （I 〉 2σ（I））. The coordination environment of Ni（II） is a distorted octahedron, and a three-dimensional structure was formed with the coordination effect of dtba2- and 4,4′-bpy ligands. The topological analysis reveals that the whole framework of 1 is a 2-nodal net of （52.6）（53.64.72.8） topology. The thermal stability and XRD pattern of 1 were also investigated
基金financially supported by the National Natural Science Foundation of China (Nos. 51973153, 22001191)。
文摘Covalent organic frameworks(COFs) are a class of crystalline porous organic materials with variable structures and fascinating properties. The intrinsic low conductivity impedes their widely application in optoelectronic. Iodine doping is an effective way to enhance the electrical conductivity of COFs. Here, a novel 3D imine COF with lvt topology is synthesized from two different pentacene derivatives with the same core in the form of structural complementarity. DDHP-COF is a highly crystalline material featuring high surface area of 1679 m^(2)/g and excellent thermal stability up to 490 ℃. Upon doping with iodine, the electrical conductivity can reach as high as 1.5×10^(-2)S/m which is significantly enhanced over 6 orders of magnitude compared with the pristine COF.
基金supported financially by the National Key Research and Development Program of China(No.2017YFB0307701).
文摘Si materials are widely considered to be the next-generation anode to replace the current commercial graphite-based anode due to its high energy density.However,the large volume variation of silicon during(de)lithiation process leads to rapid capacity decay,hindering its commercial application.Although the various hollow structure designs of Si nanomaterials have improved their cycling stability in the laboratory,the high-pressure calendering process in the current industrial electrode preparation process might collapse the hollow structure and weaken the structural advantages of hollow silicon anode materials.In this work,a silicon carbon composite material(Si@3DC)in which Si nanoparticles were anchored on a three-dimensional carbon framework through carbon films was prepared by a simple proton exchange method.The three-dimensional carbon framework with multiple hierarchical pores of Si@3DC was compatible with the high-pressure calendering process,but also could provide expansion space for Si nanoparticles during the lithiation process,and ensure good electronic and ionic conductivity.The carbon film on the surface of Si nanoparticles promoted the formation of stable solid electrolyte interphase(SEI)films,ensuring the good cycle stability of Si@3DC.
基金supported by the National Natural Science Foundation of China(Nos.62174085 and 21805136)the Program for Young Changjiang Scholars of the Ministry of Education,the Jiangsu Specially-Appointed Professors Program,the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP),the Natural Science Foundation of Jiangsu Province(No.BK20200044)the Startup Foundation for Introducing Talent of NUIST(No.2021r091).
文摘Although metal–organic frameworks have been heavily tested as the anode materials for lithium-ion batteries(LIBs),the poorer conductivity,easy collapse of frameworks,and serious volume expansion limit their further application in LIBs.Herein,we report a facile approach to obtain MXene-encapsulated porous Ni-naphthalene dicarboxylic acid(Ni-NDC)nanosheets by hybridizing ultrathin Ti_(3)C_(2)MXene and three-dimensional(3D)Ni-NDC nanosheet aggregates.In the structure of Ni-NDC/MXene hybrids,the interlayer hydrogen-bond interaction between Ni-NDC and MXene can effectively increase the interlayer spacing and further inhibit the oxidation of pure MXene.Hence,the introduction of MXene(a conductive matrix)could further improve the conductivity of Ni-NDC,avoid self-agglomeration,and buffer the volume expansion of Ni-NDC nanosheets.Benefiting from the synergistic effects between Ni-NDC and MXene,Ni-NDC/MXene hybrid electrode exhibits a reversible discharge capacity(579.8 mA∙h∙g^(−1)at 100 mA∙g^(−1)after 100 cycles)and good long-term cycling performance(310 mA∙h∙g^(−1)at 1 A∙g^(−1)after 500 cycles).
基金supported by the National Natural Science Foundation of China(Nos.21674026,21574032,51573125,51573147,51803149,51973155,and 51633007(the State Key Program))the Sino-German Center for Research Promotion(No.GZ1286)the Chinese Academy of Sciences(No.121D11KYSB20170031).
文摘Two reported three-dimensional covalent organic frameworks(3D-COFs),COF-300 and COF-301,which have hierarchical porous structures and large pore volumes,were synthesized and employed as host materials for lithium-sulfur batteries.Owing to possessing excellent porosities as well as abundant hydroxyl groups in the pore walls,COF-301 can not only trap lithium polysulfides(PSs)via physical adsorption inside the pores,but also capture PSs by chemical interactions to relieve the shuttle effect.Interestingly,it is the first time that 3D-COFs were utilized as host materials for lithium-sulfur batteries as well as hydroxyl groups were introduced into COFs for improving the battery performance.As a result,COF-301@S as cathode material could reserve the capacity of 411.6 mA·h·g^-1 after 500 cycles with only 0.081%fading per cycle at 0.5 C,exhibiting better battery performance compared with COF-300@S.This study not only expands the applications of 3D-COFs but also provides a new route for designing lithium-sulfur batteries.
基金the National Natural Science Foundation of China (No. 20171010).
文摘The open-framework iron phosphate IIIII21.543FeFe(PO) was hydrothermally synthesized and characterized by elemental analysis, IR, EPR, XPS and single crystal X-ray diffraction analysis. The title compound crystallized in the triclinic, space group P1with a=0.64724(4) nm, b=0.79651(6) nm, c=0.94229(5) nm, =104.447(2)? =108.919(4)? =101.741(4)? V=0.42302(5) nm3, Z=1 and R1 (wR2)=0.0307 (0.0793). Crystal data were collected on a Rigaku R-AXIS RAPID IP diffractometer with Mo K?(=0.071073 nm) at 293(2) K in the range of 2.43埃迹?7.46? The structure of 1 consists of 19 non-hydrogen atoms including three and a half crystallographically in-dependent Fe and three P atoms. Fe(1) connects its symmetrical Fe(1A) through bridging oxygen forming a dimer and the dimers are connected by Fe(4) forming an infinite staircase-like chain. Fe(2) and Fe(3) connect the infinite chains into a layer with bridging oxygen. Layers are interconnected via Fe(4) forming the six-membered and eight-membered channel systems.
