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超导环的磁化性质研究
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作者 马小柏 刘亮 +3 位作者 王福仁 聂瑞娟 姚丹 戴远东 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2008年第A04期424-428,共5页
计算了双结超导π环、零环及规则超导环阵列的自由能随外加磁场及温度的变化,给出了超导转变温度附近的系统相图。针对高温超导体及低温超导体中出现的顺磁迈斯纳效应,用π结、零结概念,给出了一种简单的理论解释。
关键词 超导环 π结 磁化
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C-H…O Hydrogen Bonds and π…π Interaction and the Crystal and Molecular Structures of 3-Nitro-benzylideneaniline-methyl-2’ 被引量:1
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作者 胡志辉 黄忠林 张德纯 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第4期376-380,共5页
The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = ... The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = 0.93 cm-1 and F(000) = 504.00. The final R and wR are 0.0440 and 0.1370 for 2153 observed reflections (I > 2s(I)), respectively. The dihedral angle between the two phenyl rings is 52.9 and that between the NO2 group and its attached ring is 3.0. In the crystal, molecules are stacked along [100] through p…p interactions. The CH…O hydrogen bond (3.403 ? 120.4? laterally connects the stacks along [010] to form networks (001) which are further anti- parallelly connected by CH…O (3.382 ? 142.9) and p…p interactions extending along [001]. Also presented here is a brief study on the CH…O hydrogen bonds in nitro-substituted benzyl-ideneanilines which can be classified into five types, namely, )5(12R, )4(21R, )8(22R, )6(12R and )7(22R, with the first three occurring more often. 展开更多
关键词 nitro-benzylideneaniline-methyl-2’ Schiff base C-H…O hydrogen bonds π…π interaction molecular structure crystal structure
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π-π Stacking Force in the Solid Structure of Mixed-Metal Complexes: Zn(phen)_2MS_4 (M=W, Mo)
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作者 王庆华 郭国聪 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2001年第6期481-485,共5页
The inter-diffusion of N,N-dimethylformamide solution of Zn(phen)2Cl2 and (NH4)2MS4 (M = W, Mo) in an H-shape tube produced crystals of Zn(phen)2WS4 1 and Zn(phen)2MoS4 2 (phen = 1,10-phenanthroline). The structures o... The inter-diffusion of N,N-dimethylformamide solution of Zn(phen)2Cl2 and (NH4)2MS4 (M = W, Mo) in an H-shape tube produced crystals of Zn(phen)2WS4 1 and Zn(phen)2MoS4 2 (phen = 1,10-phenanthroline). The structures of isomorphous complexes 1 and 2 have been determined by X-ray single-crystal structure analyses. Four nitrogen atoms from the phenanthroline ligands and two sulfur atoms from the MS42- anion forming a distorted octahedron coordinate each zinc atom. Through p-p interactions of adjacent aromatic rings of the phenanthroline ligands, a quasi one-dimensional zigzag-stacking column is formed in each complex. Complex 1 crystallizes in monoclinic space group C2/c, with a = 10.447(8), b = 22.016(9), c = 12.824(8) ? b = 103.56(6)? V = 2867.7(8) 3, Z = 4, C24H16N4S4WZn, Mr=737.90, Dc = 1.71 g/cm3, F(000) = 1424, m = 5.25 mm-1, the final R = 0.054 and Rw = 0.075 for 2315 observations with I > 3s (I). Complex 2 crystallizes in monoclinic space group C2/c, with a = 10.410(6), b = 22.095(7), c = 12.830(6) ? b = 103.19(8)? V = 2873.1(5) 3, Z = 4, C24H16MoN4S4Zn, Mr=649.99, Dc = 1.50 g/cm3, F(000) = 1296, m = 1.58 mm-1, the final R = 0.072 and Rw = 0.100 for 1631 observations with I > 3s(I). 展开更多
关键词 synthesis crystal structure p-p interaction zinc-molybdenum zinc-tungsten
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Synthesis and Crystal Structure of [Ni(C_5H_2N_2O_4)(2,2'bipy)(H_2O)_2]·H_2O
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作者 李星 曹荣 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2002年第4期374-377,共4页
The crystal structure of [Ni(C5H2N2O4)(2, 2?bipy)(H2O)2]?H2O 1 has been determined by X-ray diffraction. Crystal data: triclinic system, space group P with a = 7.9424(3), b = 9.9417(3), c = 12.1867(3) ? a = 84.771(1),... The crystal structure of [Ni(C5H2N2O4)(2, 2?bipy)(H2O)2]?H2O 1 has been determined by X-ray diffraction. Crystal data: triclinic system, space group P with a = 7.9424(3), b = 9.9417(3), c = 12.1867(3) ? a = 84.771(1), b = 77.375(2), g = 68.993(2)? C15H18N4O8Ni, Mr = 440.7, V = 876.16(5) 3, Z = 2, Dc = 1.672 g/cm3, F(000) = 456, m(MoKa) = 1.162 mm-1, the final R = 0.0464 and wR = 0.1055 for 3026 observed reflections with I > 2s(I). In the title compound, the nickel ion is coordinated by a nitrogen atom and an oxygen atom from the orotate ligand, two nitrogen atoms from 2, 2?bipy and two oxygen atoms from the coordinated water molecules in a distorted octahedral geometry. The presence of intermolecular hydrogen bonding and p-p stacking interaction of aromatic rings from 2, 2?bipy results in a 3D structure. 展开更多
关键词 orotic acid crystal structure hydrogen bonding -STACKING
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2D/2D S-scheme heterojunction with a covalent organic framework and g-C_(3)N_(4) nanosheets for highly efficient photocatalytic H2 evolution 被引量:2
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作者 Pengyu Dong Aicaijun Zhang +6 位作者 Ting Cheng Jinkang Pan Jun Song Lei Zhang Rongfeng Guan Xinguo Xi Jinlong Zhang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第10期2592-2605,共14页
The fabrication of S-scheme heterojunctions with fast charge transfer and good interface contacts,such as intermolecularπ–πinteractions,is a promising approach to improve photocatalytic performance.A unique two-dim... The fabrication of S-scheme heterojunctions with fast charge transfer and good interface contacts,such as intermolecularπ–πinteractions,is a promising approach to improve photocatalytic performance.A unique two-dimensional/two-dimensional(2D/2D)S-scheme heterojunction containing TpPa-1-COF/g-C_(3)N_(4) nanosheets(denoted as TPCNNS)was developed.The established maximum interfacial interaction between TpPa-1-COF NS and g-C_(3)N_(4) NS may result in aπ–πconjugated heterointerface.Furthermore,the difference in the work functions of TpPa-1-COF and g-C_(3)N_(4) results in a large Fermi level gap,leading to upward/downward band edge bending.The spontaneous interfacial charge transfer from g-C_(3)N_(4) to TpPa-1-COF at theπ–πconjugated interface area results in the presence of a built-in electric field,according to the charge density difference analysis based on density functional theory calculations.Such an enhanced built-in electric field can efficiently drive directional charge migration via the S-scheme mechanism,which enhances charge separation and utilization.Thus,an approximately 2.8 and 5.6 times increase in the photocatalytic hydrogen evolution rate was recorded in TPCNNS-2(1153μmol g^(-1) h^(-1))compared to pristine TpPa-1-COF and g-C_(3)N_(4) NS,respectively,under visible light irradiation.Overall,this work opens new avenues in the fabrication of 2D/2Dπ–πconjugated S-scheme heterojunction photocatalysts with highly efficient hydrogen evolution performance. 展开更多
关键词 Covalent organic framework g-C_(3)N_(4) π-πConjugated 2D/2D material S-Scheme heterojunction Photocatalytic hydrogen evolution
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自发磁化的超导π环在电触发下的行为 被引量:1
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作者 凌健 王科 +4 位作者 谢飞翔 马平 杨涛 王福仁 戴远东 《物理学报》 SCIE EI CAS CSCD 北大核心 2003年第7期1771-1775,共5页
运用Runge Kutta四步积分法分析了一个双结π环电路在输入脉冲电流触发下自发磁化电流的翻转过程 .发现在适当的参数条件下 ,输入周期性脉冲 ,π环环流会产生周期性翻转现象 ,由正到负和由负到正的翻转将产生不同的输出脉冲 .
关键词 自发磁化 超导π环 电触发 Runge-Kutta四步积分法 周期性翻转现象 高温超导体 π结
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