期刊文献+
共找到1,739篇文章
< 1 2 87 >
每页显示 20 50 100
Janus Quasi‑Solid Electrolyte Membranes with Asymmetric Porous Structure for High‑Performance Lithium‑Metal Batteries
1
作者 Zerui Chen Wei Zhao +4 位作者 Qian Liu Yifei Xu Qinghe Wang Jinmin Lin Hao Bin Wu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期221-232,共12页
Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion tran... Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion transference number(t^(+)) of liquid electrolyte confined in porous matrix remains challenging.Herein,we report a novel Janus MOFLi/MSLi QSEs with asymmetric porous structure to inherit the benefits of both mesoporous and microporous hosts.This Janus QSE composed of mesoporous silica and microporous MOF exhibits a neat Li^(+) conductivity of 1.5.10^(–4)S cm^(−1) with t^(+) of 0.71.A partially de-solvated structure and preference distribution of Li^(+)near the Lewis base O atoms were depicted by MD simulations.Meanwhile,the nanoporous structure enabled efficient ion flux regulation,promoting the homogenous deposition of Li^(+).When incorporated in Li||Cu cells,the MOFLi/MSLi QSEs demonstrated a high Coulombic efficiency of 98.1%,surpassing that of liquid electrolytes(96.3%).Additionally,NCM 622||Li batteries equipped with MOFLi/MSLi QSEs exhibited promising rate performance and could operate stably for over 200 cycles at 1 C.These results highlight the potential of Janus MOFLi/MSLi QSEs as promising candidates for next-generation LMBs. 展开更多
关键词 Metal-organic frameworks Mesoporous silicas Quasi-solid electrolytes Janus structure Lithium-metal battery
下载PDF
Construction of all-organic low dielectric polyimide hybrids via synergistic effect between covalent organic framework and cross-linking structure 被引量:2
2
作者 Wanjing Zhao Zhaoyang Wei +6 位作者 Chonghao Lu Yizhang Tong Jingshu Huang Xianwu Cao Dean Shi Robert KYLi Wei Wu 《Nano Materials Science》 EI CAS CSCD 2023年第4期429-438,共10页
Polyimide(PI)is a promising electronic packaging material,but it remains challenging to obtain an all-organic PI hybrid film with decreased dielectric constant and loss without modifying the monomer.Herein,a series of... Polyimide(PI)is a promising electronic packaging material,but it remains challenging to obtain an all-organic PI hybrid film with decreased dielectric constant and loss without modifying the monomer.Herein,a series of allorganic PI hybrid films were successfully prepared by introducing the covalent organic framework(COF),which could induce the formation of the cross-linking structure in the PI matrix.Due to the synergistic effects of the COF fillers and the cross-linking structure,the PI/COF hybrid film containing 2 wt%COF exhibited the lowest dielectric constant of 2.72 and the lowest dielectric loss(tanδ)of 0.0077 at 1 MHz.It is attributed to the intrinsic low dielectric constant of COF and a large number of mesopores within the PI.Besides,the cross-linking network of PI prevents the molecular chains from stacking and improves the fraction of free volume(FFV).The molecular dynamics simulation results are well consistent with the dielectric properties data.Furthermore,the PI/COF hybrid film with 5 wt%COF showed a significant enhancement in breakdown strength,which increased to 412.8 kV/mm as compared with pure PI.In addition,the PI/COF hybrid film achieve to reduce the dielectric constant and thermal expansion coefficient(CTE).It also exhibited excellent thermal,hydrophobicity,and mechanical performance.The all-organic PI/COF hybrid films have great commercial potential as next-generation electronic packaging materials. 展开更多
关键词 POLYIMIDE Covalent organic framework All-organic Cross-linking structure Dielectric property Hybrid film
下载PDF
Tuning the electronic structure of a metal-organic framework for an efficient oxygen evolution reaction by introducing minor atomically dispersed ruthenium 被引量:2
3
作者 Yuwen Li Yuhang Wu +5 位作者 Tongtong Li Mengting Lu Yi Chen Yuanjing Cui Junkuo Gao Guodong Qian 《Carbon Energy》 SCIE CSCD 2023年第2期61-71,共11页
The establishment of efficient oxygen evolution electrocatalysts is of great value but also challenging.Herein,a durable metal–organic framework(MOF)with minor atomically dispersed ruthenium and an optimized electron... The establishment of efficient oxygen evolution electrocatalysts is of great value but also challenging.Herein,a durable metal–organic framework(MOF)with minor atomically dispersed ruthenium and an optimized electronic structure is constructed as an efficient electrocatalyst.Significantly,the obtained NiRu_(0.08)-MOF with doping Ru only needs an overpotential of 187 mV at 10 mA cm^(-2) with a Tafel slop of 40 mV dec^(-1) in 0.1M KOH for the oxygen evolution reaction,and can work continuously for more than 300 h.Ultrahigh Ru mass activity is achieved,reaching 56.7 Ag^(-1)_(Ru) at an overpotential of 200 mV,which is 36 times higher than that of commercial RuO_(2).X-ray adsorption spectroscopy and density function theory calculations reveal that atomically dispersed ruthenium on metal sites in MOFs is expected to optimize the electronic structure of nickel sites,thus improving the conductivity of the catalyst and optimizing the adsorption energy of intermediates,resulting in significant optimization of electrocatalytic performance.This study could provide a new avenue for the design of efficient and stable MOF electrocatalysts. 展开更多
关键词 ELECTROCATALYSIS electronic structure metal-organic framework oxygen evolution reaction
下载PDF
Beads-on-string hierarchical structured electrocatalysts for efficient oxygen reduction reaction 被引量:3
4
作者 Yang Yuan Qing Zhang +6 位作者 Yinling Li Luyao Lv Yan Hou Ge Li Jing Fu Lin Yang Zhengyu Bai 《Carbon Energy》 SCIE CSCD 2023年第2期225-235,共11页
Rational design of hierarchically structured electrocatalysts is particularly important for electrocatalytic oxygen reduction reaction(ORR).Here,ZIF-67 crystals are stringed on core-shell Ag@C nanocables using a coord... Rational design of hierarchically structured electrocatalysts is particularly important for electrocatalytic oxygen reduction reaction(ORR).Here,ZIF-67 crystals are stringed on core-shell Ag@C nanocables using a coordinationmodulated process.Upon pyrolysis,Ag@C strings of Co nanoparticles embedded with three-dimensional porous carbon with beads-on-string hierarchical structures are developed.Due to the advantages of the rich electrochemical active sites of Co-based“beads”and the efficient electron transfer pathways via Ag@C“strings,”the resultant NH_(3)-Ag@C@Co-N-C-700 catalyst shows an improved electrocatalytic activity toward ORR.NH_(3)-Ag@C@Co-N-C-700 shows a high onset potential of 0.99 V versus RHE,a high half-wave potential of 0.88 V versus RHE,and a large limiting current of 5.8 mA cm^(-2),which are better than those of commercial Pt/C electrocatalysts.Additionally,the NH_(3)-Ag@C@Co-N-C-700 catalyst shows high stability and preeminent methanol tolerance,which makes NH_(3)-Ag@C@Co-N-C-700 a promising catalyst for oxygen electrocatalysis in fuel cell applications. 展开更多
关键词 beads-on-string structure ELECTROCATALYST metal-organic framework oxygen reduction reaction
下载PDF
A Zinc(Ⅱ) Coordination Framework Based on Terpyridine and 5-Nitroisophthalic Acid Mixed Ligands: Synthesis, Crystal Structure and Fluorescence Property 被引量:7
5
作者 陈勇强 田源 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第11期1587-1592,共6页
A new coordination framework, {[Zn(L1)(5-nipc)]·H2O}n(1, L1 = 4ˊ-(4-pyridyl)-4,2ˊ:6ˊ,4ˊˊ-terpyridine, 5-nipc = 5-nitroisophthalic acid), has been prepared under hydrothermal conditions, and determin... A new coordination framework, {[Zn(L1)(5-nipc)]·H2O}n(1, L1 = 4ˊ-(4-pyridyl)-4,2ˊ:6ˊ,4ˊˊ-terpyridine, 5-nipc = 5-nitroisophthalic acid), has been prepared under hydrothermal conditions, and determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR and powder X-ray diffraction. Complex 1 crystallizes in monoclinic, space group C2/c with a = 29.983(9), b = 13.709(3), c = 14.391(3)A, β = 114.93(4)°, V = 5364(2) A3, Dc = 1.493 g/cm^3, C28H19N5O7 Zn, Mr = 602.85, F(000) = 2464, μ(Mo Kα) = 0.972 mm^-1, Z = 8, R = 0.0935 and w R = 0.1509 for 4724 observed reflections(I 〉 2σ(I)). The structure of 1 exhibits a three-dimensional(3D) network with a layer-pillar structure. The fluorescence property of 1 is also investigated. 展开更多
关键词 coordination framework mixed-ligand approach crystal structure property
下载PDF
Hydrothermal Synthesis,Structure and Properties of a 3D Pillar-layered Metal-organic Framework Based on Amino-arenedisulfonate Ligand 被引量:6
6
作者 关磊 罗贯华 王莹 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第11期1795-1804,共10页
One novel metal-organic framework(MOF), [Ba(L)(HO)](1, HL =aniline-2,5-disulfonic acid), has been synthesized by hydrothermal method. Each barium atom is eleven-coordinated into a distorted monocapped pentagonal antip... One novel metal-organic framework(MOF), [Ba(L)(HO)](1, HL =aniline-2,5-disulfonic acid), has been synthesized by hydrothermal method. Each barium atom is eleven-coordinated into a distorted monocapped pentagonal antiprismatic arrangement. Compound 1 shows an interesting 3 D pillar-layered structure constructed from 2 D inorganic layers[Ba(SO)(HO)]and organic pillars of phenyl moieties of L2-linkages. The inorganic layers are supported by the organic pillars, generating a novel 3 D open framework structure with {3, 4~6, 5~5, 6~5,7~4}2{3}{5} topology. The result of fluorescence measurement can reveal that the decayed emission band centered at 492 nm may be caused by the interactions of the ligands and the metal ions.Compound 1 exhibits selective toward the adsorption of COover Nat 273 K. 展开更多
关键词 hydrothermal synthesis metal-organic framework pillar-layered structure coordination polymer
下载PDF
Multi-objective Optimization Design of Wing Structure with the Model Management Framework 被引量:3
7
作者 安伟刚 李为吉 苟仲秋 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2006年第1期31-35,共5页
Evolutionary algorithm is time-consuming because of the large number of evolutions and much times of finite element analysis, when it is used to optimize the wing structure of a certain high altitude long endurance un... Evolutionary algorithm is time-consuming because of the large number of evolutions and much times of finite element analysis, when it is used to optimize the wing structure of a certain high altitude long endurance unmanned aviation vehicle(UAV). In order to improve efficiency it is proposed to construct a model management framework to perform the multi-objective optimization design of wing structure. The sufficient accurate approximation models of objective and constraint functions in the wing structure optimization model are built when using the model management framework, therefore in the evolutionary algorithm a number of finite element analyses can he avoided and the satisfactory multi-objective optimization results of the wing structure of the high altitude long endurance UAV are obtained. 展开更多
关键词 wing structure UAV multi-objective opti-mization model management framework SM- MOPSO
下载PDF
Synthesis and Crystal Structure of a Zeolite-like Metal-organic Framework Based on the Triazole Ligand 被引量:4
8
作者 李东平 梁小强 +2 位作者 许岩 李承辉 游效曾 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第11期1708-1714,共7页
A novel zeolite-like metal-organic framework, [Cd12(trz)12'F10'(SiF6)3]·(H3O)4 (Htrz = 1,2,4-triazole), has been synthesized under solvothermal conditions using 1H-l,2,4-triazole-3- carboxylic acid and ... A novel zeolite-like metal-organic framework, [Cd12(trz)12'F10'(SiF6)3]·(H3O)4 (Htrz = 1,2,4-triazole), has been synthesized under solvothermal conditions using 1H-l,2,4-triazole-3- carboxylic acid and CdF2 as the starting materials. The complex has been characterized by elemental analysis, IR, SEM-EDS, gas adsorption, powder and single-crystal X-ray diffraction analyses. The title complex crystallizes in the cubic 1-43m space group, with a = 14.6436(8), V= 3140.1(3)A3, Z = 2, Mr = 2857.96, D,.= 3.023 g/cm3 and F(000) = 2668. The final R = 0.0653 and wR = 0.1880 for 586 observed reflections with 1 〉 2σ(I). In the title complex, three adjacent Cd(ll) centers are connected by three p3-bridging triazole ligands to form triagonal secondary building units (SBUs), which are further interconnected to form a three-dimensional skeleton with tetrahedral cages. 展开更多
关键词 TRIAZOLE crystal structure zeolite-like framework Cd(ll) complex
下载PDF
Land Use Structure Optimization Under Systematic Framework 被引量:2
9
作者 LIU Yanfang HUANG Liangprofessor,School of Resource and Environment Science,Wuhan University,129 Luoyu Road,Wuhan 430079,China. 《Geo-Spatial Information Science》 2002年第3期46-52,共7页
This paper puts forward the concept of land use structure optimization under space_time coupling through analyzing the systematic characteristic of land use structure optimization.It mainly expounds the construction o... This paper puts forward the concept of land use structure optimization under space_time coupling through analyzing the systematic characteristic of land use structure optimization.It mainly expounds the construction of land use structure optimization model at different levels.Lastly,this paper explains the practicableness of land use structure optimization under systematic framework through the example of Qionghai city. 展开更多
关键词 LAND USE structure OPTIMIZATION systematic framework model CONSTRAINTS
下载PDF
Precambrian Geochronology, Chronotectonic Framework and Model of Chronocrustal Structure of the Zhongtiao Mountains 被引量:10
10
作者 Sun Dazhong Li Huimin +3 位作者 Lin Yuanxian Zhou Huifang Zhao Fengqing Tang Min Tianjin Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, Tianjin Fei Zhenbi 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1992年第1期23-37,共15页
The Zhongtiao Mountains, a typical exposure area of Precambrian rocks, are a concentration area of vari-ous types of copper deposit. The rocks were dated using several dating methods. Based on the age data ob-tained b... The Zhongtiao Mountains, a typical exposure area of Precambrian rocks, are a concentration area of vari-ous types of copper deposit. The rocks were dated using several dating methods. Based on the age data ob-tained by means of three methods, several aspects are dealt with: (1) the dating results obtained by differentmethods and their geological implications have been compared; (2) a chronotectonic framework has been con-structed by means of these reliable ages, which indicates that the ages of the rocks of the Proterozoic mobilebelt fall in a time span of 2400 to 2000 Ma during which global magmatic records are lacking and reflects theages of important events in the mobile belt; (3) according to the ages of inherited zircons, neodymium modelage of the depleted mantle sources (T_(DM)) and geochemical and geological data, a model of Precambrianchronocrustal structure has been constructed, representing a typical for the North China craton. 展开更多
关键词 Precambrian Geochronology Chronotectonic framework and Model of Chronocrustal structure of the Zhongtiao Mountains
下载PDF
[(n-C_4H_9)_3SnO_2C(CH_2)_2CO_2Sn(C_4H_9-n)_3]: A Novel Three-dimensional Framework Structure of Organotin Complex 被引量:2
11
作者 尹汉东 王传华 +2 位作者 马春林 王勇 房海霞 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2003年第4期387-390,共4页
The bis(tributyltin) ester of succinic acid was synthesized by the reaction of disodium salt of succinic acid with tributyltin chloride in a molar ratio of 1:2. The crystal structure was determined by X-ray single-cry... The bis(tributyltin) ester of succinic acid was synthesized by the reaction of disodium salt of succinic acid with tributyltin chloride in a molar ratio of 1:2. The crystal structure was determined by X-ray single-crystal diffraction. It belongs to orthorhombic with space group Pccn, a = 20.949(3), b = 17.470(3), c = 20.345(3) Angstrom, V = 7446(2) Angstrom(3), Z = 8, D-c = 1.242 g/cm(3), mu = 1.365 mm(-1), F(000) = 2864, R = 0.0544 and wR = 0.1417. The tin atom is of five-coordination in a trigonal bipyramidal structure by bridging two carboxylate groups in different directions and the resulting structure which contains straight twist large ring channels along the axes of a, b and c is a three-dimensional framework polymer containing two different tin atoms. 展开更多
关键词 TRIBUTYLTIN glutaric acid crystal structure three-dimensional framework structure
下载PDF
A New 3-Fold Interpenetrating 3D Zn(Ⅱ) Metal-organic Framework: Synthesis,Structure and Luminescent Property 被引量:2
12
作者 苗少斌 李召好 +1 位作者 许春莺 吉保明 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第12期1960-1966,共7页
A new Zn(Ⅱ) coordination polymer,namely {[Zn_(1.5)(1,3,5-btc^(3-))(dtb)(H_2O)](H_2O)_2}_n(1)(1,3,5-H_3btc = 1,3,5-benzenetricarboxylic acid,dtb = 1,3-di-(1,2,4-triazole-4-yl)benzene),has been hydr... A new Zn(Ⅱ) coordination polymer,namely {[Zn_(1.5)(1,3,5-btc^(3-))(dtb)(H_2O)](H_2O)_2}_n(1)(1,3,5-H_3btc = 1,3,5-benzenetricarboxylic acid,dtb = 1,3-di-(1,2,4-triazole-4-yl)benzene),has been hydrothermally synthesized and structurally characterized. X-ray single-crystal diffraction determination reveals that 1 crystallizes in the monoclinic C2/c space group with a = 33.811(12),b = 8.406(2),c = 17.296(4) ?,β = 120.593(2)°,V = 4232(2) ?~3,Z = 4,Mr = 1142.88,Dc = 1.794 Mg/m^3,μ = 1.783 mm^(-1),F(000) = 2320,the final R = 0.0338 and wR = 0.0827 for 3043 observed reflections with I 〉 2σ(I). Compound 1 exhibits 1D Zn(Ⅱ)-carboxylate chains,which are connected into a 3D porous framework with large channels by dtb,and then three identical 3D networks are interpenetrated with each other. In addition,the luminescence property of the complex has also been investigated. 展开更多
关键词 metal-organic framework 1 3-di-(1 2 4-triazole-4-yl)benzene crystal structure luminescence
下载PDF
Auxiliary Ligand Oriented CdⅡ-flexible Dicarboxylic Acid Coordination Frameworks:Syntheses, Structures and Properties 被引量:1
13
作者 CHEN Yong-Qiang ZHAI Jia-Xin +1 位作者 TIAN Yuan LIU Xiu-Ping 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第8期1311-1319,共9页
Two different CdⅡ coordination frameworks [Cd(L1)(L2)]∞(1) and [Cd(L1)-(L3)(H2O)]∞(2) based on a flexible dicarboxylic acid ligand were obtained by introducing two different nitrogen heterocyclic auxiliary ligands(... Two different CdⅡ coordination frameworks [Cd(L1)(L2)]∞(1) and [Cd(L1)-(L3)(H2O)]∞(2) based on a flexible dicarboxylic acid ligand were obtained by introducing two different nitrogen heterocyclic auxiliary ligands(L1 = 3,3’-[1,3-benzenebis(carbonylimino)]bi(benzoate), L2 = 1,3-bi(4-pyridyl)propane, L3 = 4,4’-bipyridine). Complex 1 crystallizes in triclinic, space group P■ with a = 8.7415(5), b = 12.2247(7), c =16.2415(10) ?, β = 95.6790(10)°, V = 1525.11(16) ?3, Dc = 1.553 mg·m-3, C35H28CdN4O6, Mr = 713.02, F(000) = 724, μ(MoKα) = 0.770 mm–1, Z = 2, R/wR(I > 2σ(I))a = 0.0302/0.0773. However, complex 2 crystallizes in monoclinic, space group P21/n with a = 11.4986(7), b = 23.0911(14), c = 11.9943(8) ?, β = 115.9500(10)°, V = 2863.6(3) ?3, Dc = 1.598 mg·m-3, C32H24CdN4O7, Mr = 688.96, F(000) = 1392, μ(MoKα) = 0.820 mm–1, Z = 4, R/wR(I > 2σ(I))a = 0.0283/0.0631. The structures of two complexes were characterized. Complexes 1 and 2 have different one-dimensional(1D) chain structures. In addition, we have also made a preliminary study on the properties of the two complexes. 展开更多
关键词 COORDINATION framework AUXILIARY LIGAND structure PROPERTY
下载PDF
System Reliability Analysis for Truss Structures Based on Automatic Updated Model
14
作者 Pengyu Chen Cunbao Zhao +1 位作者 He Yao Junliang Li 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第3期2057-2071,共15页
Multiple failure modes tend to be identified in the reliability analysis of a redundant truss structure.This identification process involves updating the model for identifying the next potential failure members.Herein... Multiple failure modes tend to be identified in the reliability analysis of a redundant truss structure.This identification process involves updating the model for identifying the next potential failure members.Herein we intend to update the finite element model automatically in the identification process of failure modes and further perform the system reliability analysis efficiently.This study presents a framework that is implemented through the joint simulation of MATLAB and APDL and consists of three parts:reliability index of a single member,identification of dominant failure modes,and system-level reliability analysis for system reliability analysis of truss structures.Firstly,RSM(response surface method)combines with a constrained optimization model to calculate the reliability indices ofmembers.Then theβ-unzipping method is adopted to identify the dominant failuremodes,and the system function in MATLAB,as well as the EKILL command in APDL,is used to facilitate the automatic update of the finite element model and realize load-redistribution.Besides,the differential equivalence recursion algorithmis performed to approximate the reliability indices of failuremodes efficiently and accurately.Eventually,the PNET(probabilistic network evaluation technique)is used to calculate the joint failure probability as well as the system reliability index.Two illustrative examples demonstrate the accuracy and efficiency of the proposed system reliability analysis framework through comparison with corresponding references. 展开更多
关键词 Multiple failure modes truss structure automatic update system reliability analysis framework
下载PDF
Synthesis and Crystal Structure of a Magnesium Metal-organic Framework 被引量:1
15
作者 吴兆锋 冯美玲 +2 位作者 胡冰 黄小荥 赵玉宝 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第11期1585-1590,共6页
A magnesium metal organic framework, [N-H2(CH3)2][-N(CH3)4][Mgs(bpdc)3(O2CH)6]· 3H2O (1, bpdcH2 = 4,4'-biphenyldicarboxylic acid), has been solvothermally synthesized and structurally characterized. 1 ... A magnesium metal organic framework, [N-H2(CH3)2][-N(CH3)4][Mgs(bpdc)3(O2CH)6]· 3H2O (1, bpdcH2 = 4,4'-biphenyldicarboxylic acid), has been solvothermally synthesized and structurally characterized. 1 crystallizes in the trigonal system, space group R-3, with a = 11.3427(3), c = 41.5662(18) A, V = 4631.3(3) A^3, Z = 3 and the final R = 0.0457. Its structure features a pillared-layered three-dimensional network with 8.21 A cavities, in which cationic [NH2(CH3)2]^+ or [N(CH3)4]^+ and lattice water molecules are located. Thermal stability of the title compound has also been investigated. 展开更多
关键词 solvothermal synthesis MAGNESIUM metal organic framework crystal structure
下载PDF
Syntheses and Structures of Two Metal-organic Frameworks Constructed from Zn/Ni and 3-Formyl-4-(pyridin-4-yl)Benzoic Acid Ligand 被引量:1
16
作者 ANEES ABBAS 张杰 +3 位作者 李子建 刘燕 刘百战 崔勇 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第2期292-298,共7页
Two metal-organic frameworks [(Zn0.5L)·(H2O)]n (1) and [(Ni0.5L)?(H2O)]n (2) constructed by the 3-formyl-4-(pyridin-4-yl) benzoic acid ligand (HL) were synthesized and characterized by single-cry... Two metal-organic frameworks [(Zn0.5L)·(H2O)]n (1) and [(Ni0.5L)?(H2O)]n (2) constructed by the 3-formyl-4-(pyridin-4-yl) benzoic acid ligand (HL) were synthesized and characterized by single-crystal X-ray diffraction. 1 crystallizes in orthorhombic space group Pnna with a = 16.6152(8), b = 12.6825(6), c = 15.3908(8) A, V = 3243.2(3) ?3, Z = 4, Mr = 511.12, Dc = 1.047 g/cm3, F(000) = 1048, μ = 1.144 mm-1, GOOF = 1.061, the final R = 0.0471 and wR = 0.1262 for 12168 observed reflections with I 〉 2σ(I). 2 is isostructural to 1, which also crystallizes in orthorhombic space group Pnna with a = 16.6152(8), b = 12.6825(6), c = 15.3908(8) ?, V = 3243.2(3) ?3, Z = 4, Mr = 511.12, Dc = 1.047 g/cm3, F(000) = 1048, μ = 1.144 mm-1, GOOF = 1.061, the final R = 0.0471 and wR = 0.1262 for 12168 observed reflections with I 〉 2σ(I). Additionally, thermogravimetric analysis, FT-IR spectroscopy and powder X-ray diffraction were discussed. 展开更多
关键词 metal-organic frameworks crystal structure ZN NI FORMYL
下载PDF
Synthesis, Crystal Structure and Gas Adsorption of a Two-fold Interpenetrated Three-dimensional Framework {[Cd(2-NO_2-BDC)(4,4?-DPA)]·(DMF)}_n 被引量:1
17
作者 刘瑛 王玉玲 +2 位作者 陈岭 刘庆燕 姚阳 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第6期921-928,共8页
The reaction of Cd(NO_3)_2·4H_2O with 4,4?-dipyridylacetylene(4,4?-DPA) and 2-nitroterephthalic acid(2-NO_2-H_2BDC) in DMF/H_2O mixed solvent has afforded a compound {[Cd(2-NO_2-BDC)(4,4?-DPA)]·... The reaction of Cd(NO_3)_2·4H_2O with 4,4?-dipyridylacetylene(4,4?-DPA) and 2-nitroterephthalic acid(2-NO_2-H_2BDC) in DMF/H_2O mixed solvent has afforded a compound {[Cd(2-NO_2-BDC)(4,4?-DPA)]·(DMF)}_n(1). Compound 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetry analysis, and IR spectrum. Compound 1 crystallizes in the monoclinic system, space group P21/n, with a = 12.1488(3), b = 14.6689(3), c = 13.1615(3) ?, β = 111.809(3)o, V = 2177.63(9) ?~3, Z = 4, C_(23)H_(18)N_4O_7 Cd, M_r = 574.81, D_c = 1.753 g/cm^3, μ = 8.523 mm^(-1), F(000) = 1152, the final R = 0.0411 and wR = 0.1064 for 3589 observed reflections with I 〉 2s(I). In compound 1, the Cd(Ⅱ) ions are linked by the carboxylate groups of 2-NO_2-BDC ligands to give a two-dimensional layered structure based on the centrosymmetric dinuclear Cd_2(COO)_2 units, which are further connected by the 4,4?-DPA ligands to produce a three-dimensional framework with pcu topology. Careful examination revealed that compound 1 is a 2-fold interpenetrating framework. Furthermore, the gas adsorption properties of 1 for N_2 and CO_2 have also been investigated. 展开更多
关键词 synthesis 2-fold interpenetrating framework crystal structure gas adsorption
下载PDF
Recent advances in core-shell organic framework-based photocatalysts for energy conversion and environmental remediation
18
作者 Qibing Dong Ximing Li +9 位作者 Yanyan Duan Qingyun Tian Xinxin Liang Yiyin Zhu Lin Tian Junjun Wang Atif Sial Yongqian Cui Ke Zhao Chuanyi Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期168-199,I0004,共33页
Direct conversion of solar energy into chemical energy in an environmentally friendly manner is one of the most promising strategies to deal with the environmental pollution and energy crisis.Among a variety of materi... Direct conversion of solar energy into chemical energy in an environmentally friendly manner is one of the most promising strategies to deal with the environmental pollution and energy crisis.Among a variety of materials developed as photocatalysts,the core-shell metal/covalent-organic framework(MOF or COF)photocatalysts have garnered significant attention due to their highly porous structure and the adjustability in both structure and functionality.The existing reviews on core-shell organic framework photocatalytic materials have mainly focused on core-shell MOF materials.However,there is still a lack of indepth reviews specifically addressing the photocatalytic performance of core-shell COFs and MOFs@COFs.Simultaneously,there is an urgent need for a comprehensive review encompassing these three types of core-shell structures.Based on this,this review aims to provide a comprehensive understanding and useful guidelines for the exploration of suitable core-shell organic framework photocatalysts towards appropriate photocatalytic energy conversion and environmental governance.Firstly,the classification,synthesis,formation mechanisms,and reasonable regulation of core-shell organic framework were summarized.Then,the photocatalytic applications of these three kinds of core-shell structures in different areas,such as H_(2)evolution,CO_(2)reduction,and pollutants degradation are emphasized.Finally,the main challenges and development prospects of core-shell organic framework photocatalysts were introduced.This review aims to provide insights into the development of a novel generation of efficient and stable core-shell organic framework materials for energy conversion and environmental remediation. 展开更多
关键词 Organic framework Core-shell structure PHOTOCATALYSIS Energy conversion Environmental remediation
下载PDF
Boosting photocatalytic hydrogen evolution enabled by SiO_(2)-supporting chiral covalent organic frameworks with parallel stacking sequence
19
作者 Zheng Lin Wanting Xie +2 位作者 Mengjing Zhu Changchun Wang Jia Guo 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第9期87-97,共11页
Two-dimensional covalent organic frameworks(2D COFs)feature extendedπ-conjugation and ordered stacking sequence,showing great promise for high-performance photocatalysis.Periodic atomic frameworks of 2D COFs facilita... Two-dimensional covalent organic frameworks(2D COFs)feature extendedπ-conjugation and ordered stacking sequence,showing great promise for high-performance photocatalysis.Periodic atomic frameworks of 2D COFs facilitate the in-plane photogenerated charge transfer,but the precise ordered alignment is limited due to the non-covalentπ-stacking of COF layers,accordingly hindering out-of-plane transfer kinetics.Herein,we address a chiral induction method to construct a parallelly superimposed stacking chiral COF ultrathin shell on the support of SiO_(2) microsphere.Compared to the achiral COF analogues,the chiral COF shell with the parallel AA-stacking structure is more conducive to enhance the built-in electric field and accumulates photogenerated electrons for the rapid migration,thereby affording superior photocatalytic performance in hydrogen evolution from water splitting.Taking the simplest ketoenamine-linked chiral COF as a shell of SiO_(2) particle,the resulting composite exhibits an impressive hydrogen evolution rate of 107.1 mmol g^(-1)h^(-1)along with the apparent quantum efficiency of 14.31% at 475 nm.Furthermore,the composite photocatalysts could be fabricated into a film device,displaying a remarkable photocatalytic performance of 178.0 mmol m^(-2)h^(-1)for hydrogen evolution.Our work underpins the surface engineering of organic photocatalysts and illustrates the significance of COF stacking structures in regulating electronic properties. 展开更多
关键词 Covalent organic framework PHOTOCATALYSIS Hydrogen generation Chiral induction Core-shell structure
下载PDF
Enhancing competency of clinical research nurses:A comprehensive training and evaluation framework
20
作者 Yang-Xi Liu Yi Xu 《World Journal of Clinical Cases》 SCIE 2024年第7期1378-1381,共4页
The Sun et al's training program for clinical research nurses(CRNs)in the World Journal of Clinical Cases is a comprehensive and scientific approach.It includes structured frameworks for CRN training,aiming to imp... The Sun et al's training program for clinical research nurses(CRNs)in the World Journal of Clinical Cases is a comprehensive and scientific approach.It includes structured frameworks for CRN training,aiming to improve CRN competency.This program emphasizes practical abilities,updates training content,and improves evaluation methods.The cultivation of CRN talents focuses on enhancing the training system,establishing a multifaceted evaluation framework,and continuously refining the training programs.Regular feedback and evalua-tion are essential to improve CRNs'competency in practical settings. 展开更多
关键词 Clinical research nurse framework NURSE Operations PRACTICE structure
下载PDF
上一页 1 2 87 下一页 到第
使用帮助 返回顶部