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基于24Model-D-ISM的地铁站火灾疏散影响因素研究
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作者 孙世梅 张家严 《中国安全科学学报》 CAS CSCD 北大核心 2024年第4期153-159,共7页
为预防地铁站火灾事故,深入了解地铁站火灾人员疏散影响因素间的内在联系与层次结构,基于第6版“2-4”模型(24Model)分析63起地铁站火灾疏散事故,充分考虑各个因素之间的交互作用,提取19个影响地铁站人员疏散的关键因素,建立地铁站火灾... 为预防地铁站火灾事故,深入了解地铁站火灾人员疏散影响因素间的内在联系与层次结构,基于第6版“2-4”模型(24Model)分析63起地铁站火灾疏散事故,充分考虑各个因素之间的交互作用,提取19个影响地铁站人员疏散的关键因素,建立地铁站火灾人员疏散影响因素指标体系;采用算子客观赋权法(C-OWA)改进决策试验与评价实验法(DEMATEL),确定地铁站火灾人员疏散的重要影响因素;在此基础上,采用解释结构模型(ISM)分析各个因素间的层次结构及相互作用路径,构建地铁站火灾人员疏散影响因素的多级递阶结构模型。研究结果表明:疏散引导、恐慌从众行为、人员拥挤为地铁站火灾人员疏散的关键影响因素;地铁站火灾人员疏散受表层因素、中间层因素、深层因素共同作用的影响,其中,疏散教育与培训、设施维护与检查、疏散预案等因素是根源影响因素,重视根源影响因素的改善有利于从本质上预防和控制事故的发生。 展开更多
关键词 2-4”模型(24model) 决策试验与评价实验法(DEMATEL) 解释结构模型(ISM) 地铁站 火灾疏散 影响因素
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2-D Modeling and Calculations of Stratospheric Ozone and Influences of Convection, Diffusion, and Time
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作者 Ibraheem Alelmi Laurie Wei Sen Nieh 《Atmospheric and Climate Sciences》 2024年第2期250-276,共27页
An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical react... An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical reaction equations was developed, validated, and used for studying the ozone concentrations, distribution and peak of the layer, ozone depletion and total ozone abundance in the stratosphere. The calculated ozone concentrations and profile at both the Equator and a 60˚N location were found to follow closely with the measured data. The calculated average ozone concentration was within 1% of the measured average, and the deviation of ozone profiles was within 14%. The monthly evolution of stratospheric ozone concentrations and distribution above the Equator was studied with results discussed in details. The influences of slow air movement in both altitudinal and radial directions on ozone concentrations and profile in the stratosphere were explored and discussed. Parametric studies of the influences of gas diffusivities of ozone D<sub>O3</sub> and active atomic oxygen D<sub>O</sub> on ozone concentrations and distributions were also studied and delineated. Having both influences through physical diffusion and chemical reactions, the diffusivity (and diffusion) of atomic oxygen D<sub>O</sub> was found to be more sensitive and important than that of ozone D<sub>O3</sub> on ozone concentrations and distribution. The 2-D ozone model present in this paper for stratospheric ozone and its layer and depletion is shown to be robust, convenient, efficient, and executable for analyzing the complex ozone phenomena in the stratosphere. . 展开更多
关键词 Stratospheric Ozone 2-d model Ozone Layer Ozone Depletion CONVECTION DIFFUSION
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Synthesis and Crystal Structure of 1-(4-Fluorophenyl)-2-hexylthiobenzo[4,5]-furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H)-one 被引量:4
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作者 胡扬根 杜士明 +1 位作者 李清 丁明武 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第1期75-78,共4页
The crystal structure of the title compound 1-(4-fluorophenyl) -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H) -one(C23H21FN4O2S,Mr = 436.5) has been prepared and determined by single-cr... The crystal structure of the title compound 1-(4-fluorophenyl) -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H) -one(C23H21FN4O2S,Mr = 436.5) has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854(3) ,b = 17.2678(4) ,c = 18.1828(5)A,β = 99.364(2) °,V = 4332.58(18) A^3,Z = 4,Dc = 1.338,F(000) =1824,μ = 0.185 mm^-1,MoKa radiation(λ = 0.71073) ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I 〉 2σ(I) . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5(1H) -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions. 展开更多
关键词 SYNTHESIS crystal structure 1-(4-fluorophenyl)-2-hexylthio-benzo[4 5]furo[3 2-d]-1 2 4-triazolo[1 5-a]pyrimidin-5(1H)-one
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Synthesis and Crystal Structure of 2-Ethoxy-3-n-butyl-benzofuro [2,3-d]pyrimidin-4(3H)-one 被引量:3
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作者 胡扬根 丁明武 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第1期21-24,共4页
The crystal structure of the new title compound 2-ethoxy-3-n-butyl- benzofuro[2,3d]pyrimidin-4(3H)-one (C16H18N2O3, Mr = 286.32) has been prepared and determined by singlecrystal X-ray diffraction. The crystal is ... The crystal structure of the new title compound 2-ethoxy-3-n-butyl- benzofuro[2,3d]pyrimidin-4(3H)-one (C16H18N2O3, Mr = 286.32) has been prepared and determined by singlecrystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 13.7167(14), b = 13.113(1), c = 8.378(1) A, β = 98.992(2)^o, V = 1488.4(3) A^3, Z = 4, Dc = 1.278, F(000) = 608, μ = 0.089 mm^-1, MoKa radiation (2 = 0.71073), R = 0.0498, wR = 0.1238 for 2336 observed reflections with I 〉 2σ(I). X-ray diffraction analysis reveals that all ring atoms in the benzo[4, 5]furo [2,3-d] pyrimi- dinone moieties are almost coplanar. 展开更多
关键词 crystal structure benzo[4 5]furo[2 3-d]pyrimidin-4(3H)-one aza-Wittig reaction synthesis
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2-D crustal structure of Changbaishan-Tianchi volcanic region determined by seismic traveltime inversion 被引量:1
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作者 王夫运 张先康 杨卓欣 《Acta Seismologica Sinica(English Edition)》 CSCD 2002年第2期152-161,共10页
2-D velocity structure and tectonics of the crust and upper mantle is revealed by inversion of seismic refraction and wide-angle reflection traveltimes acquired along the profile L1 in the Changbaishan-Tianchi volcani... 2-D velocity structure and tectonics of the crust and upper mantle is revealed by inversion of seismic refraction and wide-angle reflection traveltimes acquired along the profile L1 in the Changbaishan-Tianchi volcanic region. It is used in this study that seismic traveltime inversion for simultaneous determination of 2-D velocity and interface structure of the crust and upper mantle. The result shows that, under Changbaishan-Tianchi crater, there exists a low-velocity body in the shape of an inverted triangle, and the crustal reflecting boundaries and Moho all become lower by a varying margin of 2-6 km, forming a crustal root which is assumed to be the Changbaishan-Tianchi volcanic system. Finally, we make a comparison between our 2-D velocity model and the result from the studies by using trial-and-error forward modeling with SEIS83. 展开更多
关键词 seismic traveltime inversion 2-d velocity structure Changbaishan-Tianchi volcanic system
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Synthesis and Crystal Structure of a Cu(Ⅱ) Complex with Reduced Schiff-base N-(2-Hydroxybenzyl)-D,L-alanine and 4,4'-Bipyridine 被引量:2
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作者 郑大贵 胡久荣 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第6期867-871,共5页
A new complex [Cu2(sala)2(H20)2(4,4'-bipy)]'H20 (sala = N-(2-hydroxybenzyl)- D,L-alaninate, 4,4'-bipy = 4,4'-bipyridine) has been synthesized and characterized by elemental analysis, IR spectroscopy, the... A new complex [Cu2(sala)2(H20)2(4,4'-bipy)]'H20 (sala = N-(2-hydroxybenzyl)- D,L-alaninate, 4,4'-bipy = 4,4'-bipyridine) has been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. The complex crystallizes in monoclinic system, space group C2/c with a = 42.44(3), b = 10.416(8), c = 15.487(13) ./k, fl = 97.455(14)°, C30H36Cu2N4O9, Mr = 723.71, V = 6789(9) A3, Dc = 1.416 g/cm3, Z = 8, F(000) = 2992, μ(MoKa) = 1.308 mm-1, R = 0.0493 and wR = 0.1004 for 4878 observed reflections (I 〉 2σ(I)). Structural analysis shows that each copper(II) atom displays a distorted square-based pyramidal coordination geometry with two oxygen atoms and one nitrogen atom from one N-(2-hydroxybenzyl)-D,L-alaninate, one nitrogen atom from 4,4'-bipyridine ligand and one water molecule. 4,4'-Bipyridine ligand bridges two Cu(II) ions to form a dinuclear compound. The molecular structure is extended into a one-dimensional wavy chain through hydrogen bonds. These 1D chains are further expanded into 2D networks through hydrogen bonds. 展开更多
关键词 copper(II) complex N-(2-hydroxybenzyl)-d L-alanine 4 4'-bipyridine crystal structure
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Synthesis and Crystal Structure of Ethyl 3-(4-Chlorophenyl)-3,4-dihydro-6-methyl-4-oxo-2-(pyrrolidin-1-yl)furo[2,3-d]pyrimidine-5-carboxylate 被引量:2
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作者 胡扬根 徐靖 丁明武 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第6期689-692,共4页
The crystal structure of the title compound ethyl 3-(4-chlorophenyl)-3,4-dihydro-6- methyl-4-oxo-2-(pyrrolidin-1-yl)furo[2,3-d]pyrimidine-5-carboxylate (C20H20ClN3O4, Mr= 401.84) has been prepared and determined... The crystal structure of the title compound ethyl 3-(4-chlorophenyl)-3,4-dihydro-6- methyl-4-oxo-2-(pyrrolidin-1-yl)furo[2,3-d]pyrimidine-5-carboxylate (C20H20ClN3O4, Mr= 401.84) has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 20.6215(9), b = 8.5311(4), c = 21.6886(9) A^°, β = 91.607(1)°, V = 3814.0(3)A^°^3, Z = 8, Dc = 1.400 g/cm^3, F(000) = 1680, μ = 0.233 mm^-1, R = 0.0718 and wR = 0.1545 for 6717 observed reflections with I 〉 2σ(I). X-ray diffraction analysis reveals two crystallographically independent molecules in the asymmetric unit. 展开更多
关键词 crystal structure ethyl 3-(4-ehlorophenyl)-3 4-dihydro-6-methyl-4-oxo-2- (pyrrolidin-1-yl)furo[2 3-d]pyrimidine-5-earboxylate aza-Wittig reaction synthesis
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Synthesis and Crystal Structure of 2-(3,3'-Bithiophen-2,2'-yl)dibenzothiazole (BTDB) and 2-(Dithieno[2,3-b:3',2' -d]thiophen-2,5-yl)dibenzothiazole (DTTDB) 被引量:1
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作者 李春丽 杨娟娟 +1 位作者 史建武 王华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第6期877-884,共8页
The title compounds, 2-(3,3'-bithiophen-2,2'-yl)dibenzothiazole (BTDB) and 2-(dithieno[2,3-b:3',2'-d]thiophen-2,5-yl)dibenzothiazole (DTTDB), have been synthesized and characterized by FT-IR, NMR, MS, HRM... The title compounds, 2-(3,3'-bithiophen-2,2'-yl)dibenzothiazole (BTDB) and 2-(dithieno[2,3-b:3',2'-d]thiophen-2,5-yl)dibenzothiazole (DTTDB), have been synthesized and characterized by FT-IR, NMR, MS, HRMS and X-ray single-crystal diffraction. The crystal of BTDB crystallizes in triclinic, space group P1 with a = 9.2207(17), b = 10.453(2), c = 10.969(2) A, V= 981.2(3) A3 and Z = 2. Crystal data of DTTDB: orthorhombic system, space group Pbcn with a = 4.5290(8), b = 13.576(3), c = 32.033(6) A, V= 1969.6(6) A3 and Z = 4. 展开更多
关键词 synthesis crystal structure 2-(3 3'-bithiophen-2 2'-yl)dibenzothiazole 2-(dithieno [2 3-b:3' 2-d] thiophen-2 5-yl)dihenzothiazole
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Synthesis and Crystal Structure of 2-(4’-Methylphenoxy)-5,8,9-trimethyl-3-phenyl Thieno[3′,2′:5,6]pyrido[4,3-d]pyrimidin-4-(3H)-one Hydrochloride 被引量:1
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作者 LIU Jian-Chao HE Hong-Wu DING Ming-Wu 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第5期577-581,共5页
The title compound 2-(4'-methylphenoxy)-5,8,9-trimethyl-3-phenyl thieno[3',2':5,6] pyrido[4,3-d]pyrimidin-4(3H)-one hydrochloride (C26H23Cl4N3O2S, Mr = 583.33) has been determined by single-crystal X-ray dif... The title compound 2-(4'-methylphenoxy)-5,8,9-trimethyl-3-phenyl thieno[3',2':5,6] pyrido[4,3-d]pyrimidin-4(3H)-one hydrochloride (C26H23Cl4N3O2S, Mr = 583.33) has been determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a = 14.8442( 11 ), b = 11.5131 (8), c = 17.2010(13) A, β = 113.7250(10)°, V = 2691.3(3) ,A^3, Z = 4, Dc = 1.440 g/cm^3, S = 1.094,μ = 0.547 mm^-1, F(000) = 1200, the final R = 0.0571 and wR = 0.1458. X-ray analysis reveals that the title compound combines with a molecule of dichloromethane by an intramolecular hydrogen bond. The thienopyridine ring is almost coplanar, and the dihedral angle between the thiophene plane and the pyridine plane is 0.6°. 展开更多
关键词 thieno[3' 2':5 6]pyrido[4 3-d]pyrimidin-4(3H)-one triphenylphosphine IMINOPHOSPHORANE crystal structure
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Hydrothermal Synthesis,Crystal Structure and Luminescent Properties of an Organically Templated 2-D Uranyl Sulfate
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作者 郭鸿旭 翁文 王庆华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第12期1455-1458,共4页
An organically templated 2-D uranyl sulfate, {(C2H8N)[(UO2)Cl(SO4)(H2O)] }n 1, has been hydrothermally synthesized. The crystal and molecular structures have been determined by X-ray crystallography method and... An organically templated 2-D uranyl sulfate, {(C2H8N)[(UO2)Cl(SO4)(H2O)] }n 1, has been hydrothermally synthesized. The crystal and molecular structures have been determined by X-ray crystallography method and spectral techniques. 1 belongs to monoclinic, space group P21/c with a = 8.3545(17), b = 10.550(2), c = 12.370(3)A, β = 102.64(3)°, V = 1063.9(4)A3, Mr = 464.64, De= 2.901 g/cm^3, F(000) = 836,μ = 15.710 mm^-1, Z= 4, the final R = 0.0286 and wR = 0.0685 for 10164 observed reflections with Ⅰ 〉 2σ(Ⅰ). 1 presents a two-dimensional layer-like structure constructed from infinite anionic [(UO2)Cl(H2O)(SO4)]^- layers with [C2H8N]^+ cations balancing the charge and a number of intermoleeular hydrogen bonds (C-H…O and O-H…Cl) existing in the solid state. The fluorescence properties of 1 have also been discussed. 展开更多
关键词 hydrothermal synthesis crystal structure fluorescence properties 2-d layer-like uranyl sulfate
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A Zinc TTR Complex with a Novel 2-D Structure (TTR=3-Amino-1H-1,2,4-triazole)
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作者 周薇薇 刘冰 +4 位作者 陈文通 郑发鲲 陈久桐 郭国聪 黄锦顺 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第6期703-706,共4页
The solvothermal reaction of 3-amino-1H-1,2,4-triazole (ttr) with Zn(ClO4)2·6H2O and NaCl in a 1:1:1 molar ratio gave a new complex [Zn(ttr)Cl]n with a 3-connected (4.82) 2-D structure. The layers stack... The solvothermal reaction of 3-amino-1H-1,2,4-triazole (ttr) with Zn(ClO4)2·6H2O and NaCl in a 1:1:1 molar ratio gave a new complex [Zn(ttr)Cl]n with a 3-connected (4.82) 2-D structure. The layers stack in the -ABAB- way along the c axis with abundant hydrogen bonding interactions to form the crystal structure. The complex [Zn(ttr)Cl]n crystallizes in the orthorhombic space group Pbca with a = 9.369(1), b = 10.049(1), c = 11.905(1)A, V = 1120.9(3)A^3, Z = 8.00, C2N4H3ZnCl, Mr = 183.90, Dc = 2.180 g/cm^3,μ = 4.740 mm^-1, F(000) = 720, S = 1.059 and T = 293(2) K. The final R = 0.0662 and wR = 0.2457 for 956 observed reflections with Ⅰ〉 2σ(Ⅰ), and R = 0.0689 and wR = 0.2504 for all data. 展开更多
关键词 1 2 4-TRIAZOLE zinc(Ⅱ) 2-d network (4.82 net crystal structure
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Synthesis and Crystal Structure of 7-Amino-2,3,4,5-tetrahydro-1,3-dimethyl-5-(2-nitrophenyl)-2,4-dioxo-1H-pyrano[2,3-d]pyrimidine-6-carbonitrile DMF Solvate
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作者 梁静 张梅梅 王香善 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第3期301-305,共5页
The title compound 7-amino-2,3,4,5-tetrahydro-1,3-dimethyl-5-(2-nitrophenyl)- 2,4- dioxo-1H-pyrano[2,3-d] pyrirnidine-6-carbonitrile DMF solvate 1 (C19H20N6O6, Mr = 428.41) was synthesized and crystallized. The cr... The title compound 7-amino-2,3,4,5-tetrahydro-1,3-dimethyl-5-(2-nitrophenyl)- 2,4- dioxo-1H-pyrano[2,3-d] pyrirnidine-6-carbonitrile DMF solvate 1 (C19H20N6O6, Mr = 428.41) was synthesized and crystallized. The crystal belongs to the monoclinic system, space group P2 1/c with a = 11.383(2), b = 13.372(2), c = 13.673(2)A, β = 97.380(4)°, Z = 4, V = 2063.8(6)A^3, Dc = 1.379 g/cm^3,μ(MoKα) = 0.105 mm^-1, F(000) = 896, the final R = 0.0738 and wR = 0.1647 for 2964 observed reflections (I〉 2σ(I)). X-ray analysis reveals that the new pyran ring is coplanar, which is obviously different from those of other similar compounds. In addition, the unclassical hydrogen bonds of C-H…O and C-H…N are presented in the crystals except for the normal hydrogen bonds of N-H…O. 展开更多
关键词 crystal structure pyrano[2 3-d] pyrimidine synthesis
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Efficient Synthesis,Crystal Structure and Antibacterial Activity of Two Novel Thieno[2,3-d]pyrimidin-4(3H)-one Derivatives
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作者 LI Rong-Kun YANG Quan-Li +2 位作者 HUANG Nian-Yu CHEN Hong LIU Ming-Guo 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第5期673-680,共8页
Two new thieno[2,3-d]pyrimidin-4(3H)-one derivatives,C24H22 Cl N3O2S(5a) and C25H25N3O2S(5b),have been synthesized via a tandem aza-Wittig reaction.This tandem reaction has many attractive aspects such as easily... Two new thieno[2,3-d]pyrimidin-4(3H)-one derivatives,C24H22 Cl N3O2S(5a) and C25H25N3O2S(5b),have been synthesized via a tandem aza-Wittig reaction.This tandem reaction has many attractive aspects such as easily accessible and versatile starting materials,mild conditions and high yields.Both compounds have been characterized by elemental analysis,HR-MS,IR,NMR spectra and X-ray single-crystal diffraction.Compound 5a crystallizes in monoclinic,space group P21/c with a = 9.986(3),b = 14.263(4),c = 15.530(5)A,β = 93.806(5)o,V = 2207.1(11) A^3,Mr = 451.96,Z = 4,Dc = 1.360 g/cm3,F(000) = 944,μ = 0.294 mm-1,Mo Kα radiation(λ = 0.71073 A),the final R = 0.0444 and w R = 0.1219 for 3407 observed reflections with I 〉 2σ(I).Compound 5bcrystallizes in triclinic,space group P1 with a = 8.974(4),b = 10.766(5),c = 12.260(6) A,β = 93.047(7)o,V = 1122.1(9) A^3,Mr = 431.54,Z = 2,Dc = 1.277 g/cm3,F(000) = 456,μ = 0.170 mm-1,Mo Kα radiation(λ = 0.71073 A),the final R = 0.0378 and w R = 0.1072 for 3806 observed reflections with I 〉 2σ(I).The preliminary antibacterial activities of 5a and 5b were investigated.Compound 5a showed 71.3% and 79.2% in vitro inhibition against Fusarium oxysporium and Rhizoctonia solani,respectively.Compound 5b showed 75.3% in vitro inhibition against Rhizoctonia solani. 展开更多
关键词 crystal structure thieno[2 3-d]pyrimidinone aza-Wittig reaction synthesis antibacterial activity
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Synthesis and Crystal Structure of a Novel Two-dimensional Layered Polymer [Zn(μ-O_2CCH=CHCO_2)(C_3H_4N_2)(H_2O)]_n
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作者 刘庆燕 刘平 +1 位作者 王艰 陈云 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第2期160-163,共4页
The title complex [Zn(-O2CCH=CHCO2)(C3H4N2)(H2O)]n was prepared by the reaction of zinc carbonate with maleic acid and imidazole in an aqueous-alcohol solution at 333 K, and its crystal structure has been solved by si... The title complex [Zn(-O2CCH=CHCO2)(C3H4N2)(H2O)]n was prepared by the reaction of zinc carbonate with maleic acid and imidazole in an aqueous-alcohol solution at 333 K, and its crystal structure has been solved by single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group Pc with a = 5.3858(7), b = 22.685(3), c = 7.6782(1) ? = 92.261(2)o, V = 937.4(2) 3, Z = 1, C14H16N4O10Zn2, Mr = 531.05, Dc = 1.882 g/cm3, = 2.623 mm1, F(000) = 532, the final R = 0.0372 and wR = 0.0930 for 1926 observed reflections with I>2s(I). The central zinc atom is five-coordinated in a distorted square pyramidal environment to three oxygen atoms of two different maleate ligands, a nitrogen atom of the imi- dazole ligand and an oxygen atom of water. In the complex two carboxylate groups of the maleate ligands have two coordination modes. One acts as a bidentate chelate ligand and the other a monoatomic monodentate ligand to bridge two zinc centers. As a result, 1-D infinite polymeric chains are formed, which are linked together by pairs of OH…O hydrogen bonds between the coordination water OH groups and carboxylate oxygen atoms to construct a 2-D layered polymer, and the layer structure is stabilized by p-p stacking of the imidozel ligands. 展开更多
关键词 zinc(Ⅱ) complex MALEATE synthesis crystal structure 2-d layered polymer
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Synthesis and Crystal Structure of 2-Benzylamino-6-methyl-3-cyano-8- phenyl-5H-bispyrazolo[3,4-d,3',2'-b]pyrimidine
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作者 YANG Li-Min LI Hong-Xia LIU Zhao-Jie 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第8期962-964,共3页
The title compound 2-benzylamino-6-methyl-3-cyano-8-phenyl-5H-bispyrazolo[3,4-d,3',2'-b]pyrimidine crystallizes in orthorhombic, space group Pbca with a = 17.945(7), b =10.862(4), c = 19.481(7) A°, β = 9... The title compound 2-benzylamino-6-methyl-3-cyano-8-phenyl-5H-bispyrazolo[3,4-d,3',2'-b]pyrimidine crystallizes in orthorhombic, space group Pbca with a = 17.945(7), b =10.862(4), c = 19.481(7) A°, β = 90°, Z = 8, V = 1151.8(4) A°^3, Mr = 379.43, Dx = 1.327 g/cm^3,μ(MoKa) = 0.084 mm^-1, F(000) = 1584, the final R = 0.0513 and wR = 0.1128 for 2608 observed reflections (I 〉 2σ(I)). X-ray analysis reveals that the tricyclic portion of the molecule is effectively planar. In addition, there exist three intermolecular hydrogen bonds. 展开更多
关键词 crystal structure bispyrazolo[3 4-d 3' 2'-b]pyrimidine synthesis
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On the Internal Structure of a Black Hole Utilizing a 4-D Spatial Blackbody Radiation Model
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作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2019年第3期719-772,共54页
A black hole is treated as a self-contained, steady state, spherically symmetric, 4-dimensional spatial ball filled with blackbody radiation, which is embedded in 3-D space. To model the interior distribution of radia... A black hole is treated as a self-contained, steady state, spherically symmetric, 4-dimensional spatial ball filled with blackbody radiation, which is embedded in 3-D space. To model the interior distribution of radiation, we invoke two stellar-like equations, generalized to 4-D space, and a probability distribution function (pdf) for the actual radiative mass distribution within its interior. For our purposes, we choose a truncated Gaussian distribution, although other pdf’s with support, r ∈[0, R], are possible. The variable, r = r(4), refers to the 4-D radius within the black hole. To fix the coefficients, (μ,σ), associated with this distribution, we choose the mode to equal zero, which will give maximum energy density at the center of the black hole. This fixes the parameter, μ = 0. Our black hole does not have a singularity at the center, and, moreover, it is well-behaved within its volume. The rip or tear in the space-time continuum occurs at the event horizon, as shown in a previous work, because it is there that we transition from 3-D space to 4-D space. For the shape parameter, σ , we make use of the temperature just inside the event horizon, which is determined by the mass, or radius, of the black hole. The amount of radiative heat inflow depends on mass, or radius, and temperature, T2 ≥ 2.275K , where, T2, is the temperature just outside the event horizon. Among the interesting consequences of this model is that the entropy, S(4), can be calculated as an extrinsic, versus intrinsic, variable, albeit in 4-D space. It is found that S(4) is much less than the comparable Bekenstein result. It also scales not as, R2 , where R is the radius of the black hole. Rather, it is given by an expression involving the lower incomplete gamma function, γ(s,x), and interestingly, scales with a more complicated function of radius. Thus, within our framework, the black hole is a highly-ordered state, in sharp contrast to current consensus. Moreover, the model-dependent gravitational “constant” in 4-D space, Gr(4), can be determined, and this will depend on radius. For the specific pdf chosen, Gr(4)Mr = 0.1c2(r4/σ2), where Mr is the enclosed radiative mass of the black hole, up to, and including, radius r. At the event horizon, where, r = R, this reduces to GR(4) = 0.2GR3/σ2, due to the Schwarzschild relation between mass and radius. The quantity, G, is Newton’s constant. There is a sharp discontinuity in gravitational strength at the 3-D/4-D interface, identified as the event horizon, which we show. The 3-D and 4-D gravitational potentials, however, can be made to match at the interface. This lines up with previous work done by the author where a discontinuity between 3-D and 4-D quantities is required in order to properly define a positive-definite radiative surface tension at the event horizon. We generalize Gauss’ law in 4-D space as this will enable us to find the strength of gravity at any radius within the spherically symmetric, 4-D black hole. For the pdf chosen, gr(4) = Gr(4)Mr/r3 = 0.1c2r/σ2, a remarkably simple and elegant result. Finally, we show that the work required to assemble the black hole against radiative pressure, which pushes out, is equal to, 0.1MRc2. This factor of 0.1 is specific to 4-D space. 展开更多
关键词 BLACK HOLE 4-d SPATIAL BLACKBODY Radiation model Internal structure RADIATIVE Pressure
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Synthesis,Crystal Structure and Anti-tumor Activity of 2-(2-Chloro-4-nitrophenyl)-4-(4-chlorophenyl)-3a,4-diethoxy-2,3,3a,4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole
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作者 应华洲 孙茂堂 +1 位作者 刘滔 胡永洲 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第10期1171-1174,共4页
The title compound 2-(2-chloro-4-nitrophenyl)-4-(4-chlorophenyl)-3a,4- diethoxy- 2,3,3a, 4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole 2 (C29H30Cl2N3O7P, Mr = 633.44) was synthesized and its structure was cha... The title compound 2-(2-chloro-4-nitrophenyl)-4-(4-chlorophenyl)-3a,4- diethoxy- 2,3,3a, 4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole 2 (C29H30Cl2N3O7P, Mr = 633.44) was synthesized and its structure was characterized by IR, MS, ^1H NMR, ^13C NMR, ^31p NMR, elemental analysis and single-crystal X-ray diffraction. It crystallizes in triclinic, space group P1^-, a = 9.1549(3), b = 10.7168(4), c = 17.6272(6)A, α = 102.9363(12), β = 90.2713(9), γ = 117.4265(10)°, V= 1484.41(9)A^3, Z= 2,μ(MoKa) = 0.323, F(000) = 658, Z= 2, De= 1.417 g/cm^3, the final R = 0.0687 and wR = 0.2066 for 4943 observed reflections (I 〉 2σ(I)). X-ray analysis reveals that the diazaphospholine ring is almost planar and the two ethoxy groups bonded on the 3a- and 4-positions are in trans configurations. Its antiproliferative activity was also tested in vitro against four human tumor cell lines. 展开更多
关键词 SYNTHESIS crystal structure 2-(2-chloro-4-nitrophenyl)-4-(4-chlorophenyl)-3a 4-diethoxy-2 3 3a 4-tetrahydrochromeno[3 4-d] [1 2 3]dlazaphosphole ANTITUMOR
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Numerical simulation of rock pore-throat structure effects on NMR T_2 distribution 被引量:4
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作者 王克文 李宁 《Applied Geophysics》 SCIE CSCD 2008年第2期86-91,共6页
We built a three-dimensional irregular network model which can adequately describe reservoir rock pore-throat structures. We carried out numerical simulations to study the NMR T2 distribution of water-saturated rocks.... We built a three-dimensional irregular network model which can adequately describe reservoir rock pore-throat structures. We carried out numerical simulations to study the NMR T2 distribution of water-saturated rocks. The results indicate that there is a good correlation between T2 distribution and the pore radius frequency histogram. The total T2 distribution can be partitioned into pore body and pore throat parts. The effect of parameters including throat radius, pore-throat ratio, and coordination number of the micro- pore structure on the T2 distribution can be evaluated individually. The result indicates that: 1 ) with the increase of the pore throat radius, the T2 distribution moves toward longer relaxation times and its peak intensity increases; 2) with the increase of the pore-throat ratio, the T2 distribution moves towards longer T2 with the peak intensity increasing and the overlap between pore body T2 and pore throat T2 decreasing; 3) With the increase of connectivity, the short T2 component increases and peak signal intensity decreases slightly. 展开更多
关键词 Network model NMR T2 distribution Pore structure Microstructure modeling
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中青年2型糖尿病病人健康饮食行为阶段的影响因素
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作者 吴娜 蒙连新 《护理研究》 北大核心 2024年第18期3218-3226,共9页
目的:基于结构方程模型分析中青年2型糖尿病病人(T2DM)健康饮食行为阶段的影响因素。方法:于2021年9月—2022年6月采用便利抽样法选取广西壮族自治区百色市某三级甲等医院内分泌科收治的280例中青年T2DM病人为研究对象,采用一般资料调... 目的:基于结构方程模型分析中青年2型糖尿病病人(T2DM)健康饮食行为阶段的影响因素。方法:于2021年9月—2022年6月采用便利抽样法选取广西壮族自治区百色市某三级甲等医院内分泌科收治的280例中青年T2DM病人为研究对象,采用一般资料调查表、健康饮食行为阶段问卷、负面社会支持互动量表、糖尿病态度量表、糖尿病管理自我效能量表进行调查,随后采用有序逻辑回归以及结构方程模型对中青年T2DM病人健康饮食行为阶段的影响因素进行分析。结果:280例中青年T2DM病人中,处于前意向阶段46例(16.4%),意向阶段87例(31.1%),准备阶段82例(29.3%),行动阶段46例(16.4%),维持阶段19例(6.8%)。回归分析结果显示,文化程度、病程、并发症、糖尿病住院史、糖化血红蛋白、糖尿病态度、负面社会支持互动、糖尿病管理自我效能对病人健康饮食行为阶段的改变有影响(P<0.05)。结构方程模型显示,糖尿病管理自我效能对健康饮食行为的前意向阶段、意向阶段、准备阶段和行动阶段均有直接影响,糖尿病态度和负面社会支持互动可以通过糖尿病管理自我效能对健康饮食行为阶段产生间接影响。结论:中青年T2DM病人健康饮食行为阶段受多种因素影响,医务人员应针对影响因素对病人进行干预,以改善其健康饮食行为。 展开更多
关键词 中青年 2型糖尿病 饮食行为 影响因素 结构方程模型 护理
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Calculations and Sensitivity Analysis of Chlorine-,NO_(x)-,and Bromine-Depleting Cycles of Stratospheric Ozone
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作者 Ibraheem Alelmi Sen Nieh 《Journal of Environmental Science and Engineering(B)》 CAS 2024年第2期53-69,共17页
This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozon... This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozone-generating,and-depleting chemical reactions,the model calculated the transient,spatial changes of ozone under different physical-chemical-radiative conditions.Validation against the measured data demonstrated good accuracy,close match of our model with the observed ozone concentrations at both 20°S and 90°N locations.The deviation in the average concentration was less than 1% and in ozone profiles less than 17%.The impacts of various chlorine-(Cl),nitrogen oxides-(NO_(x)),and bromine-(Br)depleting cycles on ozone concentrations and distribution were investigated.The chlorine catalytic depleting cycle was found to exhibit the most significant impact on ozone dynamics,confirming the key role of chlorine in the problem of ozone depletion.Sensitivity analysis was conducted with levels of 25%,50%,100%,200%,and 400% of the baseline value.The combined cycles(Cl+NO_(x)+Br)showed the most significant influence on ozone behavior.The total ozone abundance above the South Pole could decrease by a small 3%,from 281 DU(Dubson Units)to 273 DU for the 25% level,or by a huge thinning of 60%to 114 DU for the 400% concentration level.When the level of chlorine gases increased beyond 200%,it would cause ozone depletion to a level of ozone hole(below 220 DU).The 2D Ozone Model presented in this paper demonstrates robustness,convenience,efficiency,and executability for analyzing complex ozone phenomena in the stratosphere. 展开更多
关键词 Ozone depletion 2-d model CHLORINE BROMINE nitrogen oxides sensitivity analysis total ozone abundance DU
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