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Quasi-real time inversion method of three-dimensional epicenter coordinate, trigger time, and magnitude based on CORS 被引量:1
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作者 Xiao Dongsheng Chang Ming +2 位作者 Su Yong Hu Qijun Yu Bing 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2016年第3期425-433,共9页
This study explores the quasi-real time inversion principle and precision estimation of three-dimensional coordinates of the epicenter, trigger time and magnitude of earthquakes with the aim to improve traditional met... This study explores the quasi-real time inversion principle and precision estimation of three-dimensional coordinates of the epicenter, trigger time and magnitude of earthquakes with the aim to improve traditional methods, which are flawed due to missing information or distortion in the seismograph records. The epicenter, trigger time and magnitude from the Lushan earthquake are inverted and analyzed based on high-frequency GNSS data. The inversion results achieved a high precision, which are consistent with the data published by the China Earthquake Administration. Moreover, it has been proven that the inversion method has good theoretical value and excellent application prospects. 展开更多
关键词 continuous operation reference station (CORS) trigger time three dimensional coordinate MAGNITUDE inversion
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Comprehensive two-dimensional river ice model based on boundary-fitted coordinate transformation method 被引量:1
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作者 Ze-yu MAO Jing YUAN +2 位作者 Jun BAO Xiao-fan PENG Guo-qiang TANG 《Water Science and Engineering》 EI CAS CSCD 2014年第1期90-105,共16页
River ice is a natural phenomenon in cold regions, influenced by meteorology, geomorphology, and hydraulic conditions. River ice processes involve complex interactions between hydrodynamic, mechanical, and thermal pro... River ice is a natural phenomenon in cold regions, influenced by meteorology, geomorphology, and hydraulic conditions. River ice processes involve complex interactions between hydrodynamic, mechanical, and thermal processes, and they are also influenced by weather and hydrologic conditions. Because natural rivers are serpentine, with bends, narrows, and straight reaches, the commonly-used one-dimensional river ice models and two-dimensional models based on the rectangular Cartesian coordinates are incapable of simulating the physical phenomena accurately. In order to accurately simulate the complicated river geometry and overcome the difficulties of numerical simulation resulting from both complex boundaries and differences between length and width scales, a two-dimensional river ice numerical model based on a boundary-fitted coordinate transformation method was developed. The presented model considers the influence of the frazil ice accumulation under ice cover and the shape of the leading edge of ice cover during the freezing process. The model is capable of determining the velocity field, the distribution of water temperature, the concentration distribution of frazil ice, the transport of floating ice, the progression, stability, and thawing of ice cover, and the transport, accumulation, and erosion of ice under ice cover. A MacCormack scheme was used to solve the equations numerically. The model was validated with field observations from the Hequ Reach of the Yellow River. Comparison of simulation results with field data indicates that the model is capable of simulating the river ice process with high accuracy. 展开更多
关键词 two-dimensional river ice numerical model boundary-fitted coordinate technology river ice process freeze-up MacCormack scheme natural river
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A One-dimensional Cd(Ⅱ)Coordination Polymer Constructed from 1,4-Benzene-dicarboxylic Acid and 3-(2,6-Di(pyrazin-2-yl)pyridin-4-yl)-1H-indole:Synthesis,Structure and Photoluminescence 被引量:2
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作者 谢玲 卢丽萍 朱苗力 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第10期1606-1614,共9页
A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-... A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-dicarboxylic acid(H2bdc) and cadmium(Ⅱ) nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012(4),b = 31.881(6),c = 19.808(4) ?,V = 12638(4) ?~3,Z = 16,C_(29)H_(20)CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm^(-3),μ = 0.735 mm^(-1),F(000) = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections(I 〉 2σ(I)). The Cd(Ⅱ) centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd(Ⅱ) cations into a one-dimensional(1D) coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178(1) ?. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional(3D) structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ?~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm. 展开更多
关键词 1 4-benzenedicarboxylic acid 3-(2 6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole one-dimensional cadmium(Ⅱ) coordination polymer π···π stacking interactions photoluminescence
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A New Two-dimensional Cd(Ⅱ) Coordination Polymer Constructed by Pyridine-2,5-dicarbohydrazide
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作者 张庆富 杨明 +2 位作者 熊克才 江飞龙 洪茂椿 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第7期807-812,共6页
A new two-dimensional Cd(Ⅱ) coordination polymer, [Cd(2,5-pdch)(H2O)]n·2n(ClO4)·nH2O (2,5-pdch = pyridine-2,5-dicarbohydrazide), was prepared and characterized by elemental analysis, IR spectra an... A new two-dimensional Cd(Ⅱ) coordination polymer, [Cd(2,5-pdch)(H2O)]n·2n(ClO4)·nH2O (2,5-pdch = pyridine-2,5-dicarbohydrazide), was prepared and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/c with a = 10.905(2), b = 11.602(1), c = 15.034(2) A, β = 117.794 (10°, V = 1682.8(4A3, Z = 4, C7H13CdCl2NsO12, Mr = 542.52, Dc = 2.141 g/cm^3,/μ = 1.691 mm^-1, F(000) = 1072, 2(MoKa) = 0.71073A, the final R = 0.0608 and wR = 0.1329 for 2972 observed reflections with I 〉 2σ(I). Single-crystal X-ray diffraction analysis reveals that the Cd(Ⅱ) atom displays a distorted pentagonal-bipyramidal geometry coordinated by three N atoms and three O atoms from three different 2,5-pdch ligands, and one water molecule. Interestingly, each two Cd(Ⅱ) atoms are bridged by two carbohydrazide groups of the 2,5-pdch ligands to form a dimeric unit, and such dimeric units are further connected by the 2,5-pdch ligand to generate a two-dimensional (4,4)-network. 展开更多
关键词 cadmium (Ⅱ) TWO-dimensional coordination polymer CARBOHYDRAZIDE
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One-dimensional Copper(Ⅱ) Complex Constructed with Nitrate Counter-anion as Bitopic Connector
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作者 Chun Hua GE Xiang Dong ZHANG +1 位作者 Wei GUAN Qi Tao LIU 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第9期1255-1258,共4页
Coordination polymer {[Cu(NPPCA)3(NO3)(H20)]-NOyH20}n 1 ( NPPCA = N-(4'- nitrophenyl)-4-pyridinecarboxamide) has been synthesized by the reaction of NPPCA with copper(H) nitrate in ethanol-water solution ... Coordination polymer {[Cu(NPPCA)3(NO3)(H20)]-NOyH20}n 1 ( NPPCA = N-(4'- nitrophenyl)-4-pyridinecarboxamide) has been synthesized by the reaction of NPPCA with copper(H) nitrate in ethanol-water solution and characterized by X-ray diffraction. 1 crystallizes in the monoclinic space, group P21/n, a = 17.341(6)A, b = 6.744(2)A, c = 34.555(12)A, β = 100.493(6)°, V = 3974(2) A^3, Z = 4. Each copper(H) ion has a distorted octahedral coordination geometry. Nitrate anion adopts the unusual coordination mode linking two adjacent copper(H) ions to form a one-dimensional coordination polymer and these chains are further linked by noncovalent interactions. 展开更多
关键词 Copper(H) complex one-dimensional coordination polymer bidentate nitrate non-covalent interaction
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Stability Analysis of Contact Scanning Probe for Micro/Nano Coordinate Measuring Machine 被引量:2
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作者 李瑞君 范光照 +3 位作者 钱剑钊 黄强先 龚伟 苗晋伟 《纳米技术与精密工程》 EI CAS CSCD 2012年第2期125-131,共7页
关键词 微纳米三坐标测量机 扫描探头 稳定性分析 传感哭喊中
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Enhanced hyperspectral imagery representation via diffusion geometric coordinates
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作者 何军 王庆 李滋刚 《Journal of Southeast University(English Edition)》 EI CAS 2009年第3期351-355,共5页
The concise and informative representation of hyperspectral imagery is achieved via the introduced diffusion geometric coordinates derived from nonlinear dimension reduction maps - diffusion maps. The huge-volume high... The concise and informative representation of hyperspectral imagery is achieved via the introduced diffusion geometric coordinates derived from nonlinear dimension reduction maps - diffusion maps. The huge-volume high- dimensional spectral measurements are organized by the affinity graph where each node in this graph only connects to its local neighbors and each edge in this graph represents local similarity information. By normalizing the affinity graph appropriately, the diffusion operator of the underlying hyperspectral imagery is well-defined, which means that the Markov random walk can be simulated on the hyperspectral imagery. Therefore, the diffusion geometric coordinates, derived from the eigenfunctions and the associated eigenvalues of the diffusion operator, can capture the intrinsic geometric information of the hyperspectral imagery well, which gives more enhanced representation results than traditional linear methods, such as principal component analysis based methods. For large-scale full scene hyperspectral imagery, by exploiting the backbone approach, the computation complexity and the memory requirements are acceptable. Experiments also show that selecting suitable symmetrization normalization techniques while forming the diffusion operator is important to hyperspectral imagery representation. 展开更多
关键词 hyperspectral imagery diffusion geometric coordinate diffusion map nonlinear dimension reduction
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Single Camera 3-D Coordinate Measuring System Based on Optical Probe Imaging 被引量:4
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作者 MAShu-ying YUZhi-jing 《Semiconductor Photonics and Technology》 CAS 2001年第4期235-240,共6页
A new vision coordinate measuring system--single camera 3 D coordinate measuring system based on optical probe imaging is presented. A new idea in vision coordinate measurement is proposed. A linear model is deduced w... A new vision coordinate measuring system--single camera 3 D coordinate measuring system based on optical probe imaging is presented. A new idea in vision coordinate measurement is proposed. A linear model is deduced which can distinguish six freedom degrees of optical probe to realize coordinate measurement of the object surface. The effects of some factors on the resolution of the system are analyzed. The simulating experiments have shown that the system model is available. 展开更多
关键词 Three dimensional measurement Vision coordinate measurement Optical probe Linear model
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A New Two-dimensional Copper(II) Complex with p-PhDTA Bridges 被引量:1
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作者 郑磊 倪中海 +4 位作者 黎文路 张丽芳 葛春华 崔爱莉 寇会忠 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第7期793-796,共4页
A new p-PhDTA bridged Cu(II) complex [Cu2(p-PhDTA)(DMSO)2]·4DMSO (p-PhDTA = p-phenylenediamine-N,N,N,N'-tetraacetic acid) has been synthesized and structurally characterized. The crystal belongs to ortho... A new p-PhDTA bridged Cu(II) complex [Cu2(p-PhDTA)(DMSO)2]·4DMSO (p-PhDTA = p-phenylenediamine-N,N,N,N'-tetraacetic acid) has been synthesized and structurally characterized. The crystal belongs to orthorhombic, space group Pca21 with a = 19.572(4), b = 19.552(4), c = 10.156(2)A, C26H48N2O14CU2S6, Mr = 932.10, V = 3886.4(13)A3, Z = 4, Dc = 1.593 g/cm^3, F(000) = 1936, λ(MoKa) = 0.71073A,μ = 1.480, R = 0.0487 and wR = 0.1151 for 8464 observed reflections (I 〉2σ(I)). In the complex, the oxygen atoms of carboxylate of p-PhDTA connect the Cu atoms in a syn-anti type, giving one-dimensional chains which are further linked by the benzene groups ofp-PhDTA to form a novel two-dimensional structure. 展开更多
关键词 COPPER TWO-dimensional coordination polymer CARBOXYLATE
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Three-dimensional tidal current numerical model of the Oujiang Estuary 被引量:2
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作者 LI Mengguo LI Wendan 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2009年第3期17-25,共9页
The characteristics of three-dimensional (3-D) tidal current in the Oujiang Estuary are investigated according to in situ observations. The Oujiang Estuary has features of irregular coastline, complex topography, ma... The characteristics of three-dimensional (3-D) tidal current in the Oujiang Estuary are investigated according to in situ observations. The Oujiang Estuary has features of irregular coastline, complex topography, many islands, moveable boundary, and submerged dyke, therefore, σ 3-D numerical model oil an unstructured triangular grid has been degeloped. The σ coordinate transforination, the moveable boundary and submerged dyke treatment techniques were employed in the model so it is suitable for the tidal simulations in the Oujing Estuary with submerged dyke and moveable boundary problems. The model is evaluated with the in situ data, and the results show that the calculated water elevations at 19 stations and currents at 19 profiler stations are in good agreement with measured data both in magnitude and phase. This numerical model is applied to the 3-D tidal circulation simulations of experiments in stopping flow transport through the South Branch of the Oujiang Estuary, and the feasibility to cutoff the flow in the South Branch of the Oujiang Estuary is demonstrated by numerical simulation experiments. The developed numerical model simulated the 3-D tidal current circulations in complicated coastal and estuarine waters very well. 展开更多
关键词 Oujiang Estuary three-dimensional tidal current mathematical model numerical simulation triangular grid σ coordinate transformation
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APPROXIMATION THEORY OF THREE DIMENSIONAL ELASTIC PLATES AND ITS BOUNDARY CONDITIONS WITHOUT USING KIRCHHOFF-LOVE ASSUMPTIONS
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作者 钱伟长 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1995年第3期203-224,共16页
The classical small deflection theory of elastic plates id based on the Kirchhoff-Lore assumptions ̄[1,2].Ther are used on the basis of the thinness of plate and the smallness of deflection.In terms of Cartesian tens... The classical small deflection theory of elastic plates id based on the Kirchhoff-Lore assumptions ̄[1,2].Ther are used on the basis of the thinness of plate and the smallness of deflection.In terms of Cartesian tensor coordinates x_i(i=0, 12)these basic assumptions are:(1)the transversal normal strain may be neglected i.e._(00)=0;(2)the transversal shear strain may be neglected i.e.e_(0α)=0(α= 1, 2)(3)the transversal normal stress may be neglected i.e.. σ_(00)=0 .In classical theory of elastic plates,the strain-displacement relations and the corresponding stress-displacement relations are established on the basis of these assumptions. And the equations of the classical theory for a set of undetermined quantities defined on the middle surface are established through integrating the three dimensional equations of equilibrium of stress over the thickness.In the previous papers ̄[3,4,5],an approximation theory is given on the basis of Ihree dimensional theory of elastic plates without using Kirchhoff-Love assumptions。However,no uniqueness study is given,and also the boundary conditions have never been studied. In this paper.the same problems are studied on the basis of generalizedvariational principle of the three dimensional theory of elastic bodies ̄[6].The stationary conditions of variation give an unique and complete set of field equations and the related boundary conditions for the approximation theory.In this paper,the first order approximation theory is studied in detail. 展开更多
关键词 three dimensional elastic plates. Kirchhoff-Love assumptions.Cartesian TENSOR coordinateS
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Synthesis, Structure and Decarboxylative Behavior of a Nitro-coordinated Potassium Compound
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作者 LI Dong-Mi CUI Jia-Jia +2 位作者 YAO Jia-Xin LI Zhao-Hao ZHAO Bang-Tun 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第3期362-368,共7页
A novel nitro-coordinated potassium compound [K(Htdc)(H_2O)]_n(tdc = 3-nitro-thiophene-2,5-dicarboxylate), has been synthesized and characterized. The complex with a two-dimensional(2D) layer structure contains an inf... A novel nitro-coordinated potassium compound [K(Htdc)(H_2O)]_n(tdc = 3-nitro-thiophene-2,5-dicarboxylate), has been synthesized and characterized. The complex with a two-dimensional(2D) layer structure contains an infinite K-O ladder-shaped chain, which is connected through carboxyl and unusual nitro-coordination of Htdc– anion. Then the 2D layers are further extended by intermolecular hydrogen-bonding to form a three-dimensional(3D) supramoleculalr network. Variable temperature powder X-ray diffractions, thermogravimetric analysis and nuclear magnetic resonance studies exhibit that the compound has a thermal-induced decarboxylative behavior. 展开更多
关键词 crystal STRUCTURE coordinATION mode two-dimensional COMPOUND decarboxylative behaviour
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Using three-dimensional discrete spherical Fourier descriptors based on surface curvature voxels for pollen particle recognition
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作者 谢永华 Michael OhEigeartaigh 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第11期236-242,共7页
This paper presents a new method for extract three-dimensional (3D) discrete spherical Fourier descriptors based on surface curvature voxels for pollen particle recognition. In order to reduce the high amount of pol... This paper presents a new method for extract three-dimensional (3D) discrete spherical Fourier descriptors based on surface curvature voxels for pollen particle recognition. In order to reduce the high amount of pollen information and noise disturbance, the geometric normalized curvature voxels with the principal curvedness are first extracted to represent the intrinsic pollen volumetric data. Then the curvature voxels are decomposed into radial and angular components with spherical harmonic transform in spherical coordinates. Finally the 3D discrete Fourier transform is applied to the decomposed curvature voxels to obtain the 3D spherical Fourier descriptors for pollen recognition. Experimental results show that the presented descriptors are invariant to different pollen particle geometric transformations, such as pose change and spatial rotation, and can obtain high recognition accuracy and speed simultaneously. 展开更多
关键词 curvature voxels spherical coordinates three-dimensional discrete Fourier descriptors pollen particles recognition
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Least squares fitting of coordinate parameters model
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作者 YU Sheng-wen~(1), DONG Jun~(2), WANG Ai-min~(3) (1. Shandong University of Science and Technology, Tai’an 271019, China 2. Bao’an Coal Mine of Huaning Group, Hua’ning, Tai’an 271000, China 3. The Plan Bureau of Laiwu, Laiwu 272000, China) 《中国有色金属学会会刊:英文版》 CSCD 2005年第S1期197-199,共3页
This paper starts with untime-diversification of the time-diversification deformation model and gives displacement distribution model of untime-diversification and simplifies further the study of deformation model. Th... This paper starts with untime-diversification of the time-diversification deformation model and gives displacement distribution model of untime-diversification and simplifies further the study of deformation model. The paper discusses the problem of least squares fitting of coordinate parameters model—parameters of deformation model. During discussion, the basic means of cubic B splines and two steps of multidimensional disorder datum fitting are adopted which can make fitting function calculated mostly approximate coordinate parameters model and it can make calculation easier. 展开更多
关键词 coordinate parameter MODEL least SQUARES FITTING two STEPS of MULTI-dimensional disorder data curve FITTING
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One-dimensional (1D) europium coordination polymer wires:Synthesis,characterization and photoluminescence properties 被引量:1
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作者 罗龙飞 徐蓉 +1 位作者 赵东 钟声亮 《Journal of Rare Earths》 SCIE EI CAS CSCD 2010年第S1期106-110,共5页
1D europium coordination polymer wires were successfully prepared by reacting europium chloride with tributyl phosphate(TBP) at 160 oC for 12 h. The products were characterized by XRD,IR,TG,DTA,SEM,and EDS. SEM result... 1D europium coordination polymer wires were successfully prepared by reacting europium chloride with tributyl phosphate(TBP) at 160 oC for 12 h. The products were characterized by XRD,IR,TG,DTA,SEM,and EDS. SEM results showed that the wires were with diameters ranging from several hundreds of nanometers to ~5 μm and lengths going up to several hundreds of micrometers. Influencing factors such as the dosage of reactants and reaction time on the preparation were systematically investigated. Strong emission centering at 590 nm was realized in the coordination polymer wires on excitation at 395 nm. 展开更多
关键词 one dimensional solvothermal synthesis EUROPIUM coordination polymer rare earths
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A review on the coordinative structure of human walking and the application of principal component analysis 被引量:1
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作者 Xinguang Wang Nicholas O'Dwyer Mark Halaki 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第7期662-670,共9页
Walking is a complex task which includes hundreds of muscles, bones and joints working together to deliver smooth movements. With the complexity, walking has been widely investigated in order to identify the pattern o... Walking is a complex task which includes hundreds of muscles, bones and joints working together to deliver smooth movements. With the complexity, walking has been widely investigated in order to identify the pattern of multi-segment movement and reveal the control mechanism. The degree of freedom and dimensional properties provide a view of the coordinative structure during walking, which has been extensively studied by using dimension reduction technique. In this paper, the studies related to the coordinative structure, dimensions detection and pattern reorganization during walking have been reviewed. Principal component analysis, as a popular technique, is widely used in the processing of human movement data. Both the principle and the outcomes of principal component analysis were introduced in this paper. This technique has been reported to successfully reduce the redundancy within the original data, identify the physical meaning represented by the extracted principal components and discriminate the different patterns. The coordinative structure during walking assessed by this technique could provide further information of the body control mechanism and correlate walking pattern with injury. 展开更多
关键词 neural regeneratJon REVIEWS human walking coordinative structure pattern synergy principalcomponent analysis dimension reduction GENDER walking speed correlation linear systemanalysis COHERENCE NEUROREGENERATION
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A Novel 3-D Zn(Ⅱ) Coordination Polymer for Inhibiting the Human Osteosarcoma Cells Growth 被引量:1
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作者 张帆 彭昊 +2 位作者 尚峥辉 梁杰 茹能 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第7期1019-1023,共5页
A new three-dimensional Zn(II) coordination polymer, namely [Zn4(bpydb)3(tz)2(H2O)2]n(1), has been synthesized by the self-assembly reactions of Zn(NO3)2·6H2O, bpydb H2, Htz and DMF. Single-crystal X-... A new three-dimensional Zn(II) coordination polymer, namely [Zn4(bpydb)3(tz)2(H2O)2]n(1), has been synthesized by the self-assembly reactions of Zn(NO3)2·6H2O, bpydb H2, Htz and DMF. Single-crystal X-ray structural analysis reveals that compound 1 features a three-dimensional framework structure and is the first example of Zn-containing coordination polymers based on two kinds of ligands bpydb H2 and Htz. It crystallizes in triclinic, space group P1 with a = 14.9953(12), b = 17.5335(17), c = 20.2381(11)A, α = 115.225(7), β = 92.329(5), γ = 105.606(8)o, V = 4561.9(7) A^3, Z = 2, F(000) = 1644, Dc = 1.177 Mg/m^3, Mr = 1616.76 and μ = 1.098 mm^-1. The antitumor activities of compound 1 and its corresponding organic ligands(bpydb H2 and Htz) were investigated for inhibiting human osteosarcoma cells(MG-63 and U-2 OS) growth by MTT assay. It was found that compared with the two ligands, compound 1 exerted rather potent activities against all of these cell lines. 展开更多
关键词 coordination X-ray three-dimensional
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One-dimensional π-d conjugated coordination polymers: synthesis and their improved memory performance 被引量:1
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作者 Xue-Feng Cheng Jie Li +7 位作者 Xiang Hou Jin Zhou Jing-Hui He Hua Li Qing-Feng Xu Na-Jun Li Dong-Yun Chen Jian-Mei Lu 《Science China Chemistry》 SCIE EI CAS CSCD 2019年第6期753-760,共8页
Multilevel resistance random access memories(RRAMs) are intensively studied due to their potential applications in high density information storage. However, the low ternary device yields and high threshold voltages b... Multilevel resistance random access memories(RRAMs) are intensively studied due to their potential applications in high density information storage. However, the low ternary device yields and high threshold voltages based on current materials cannot meet the requirement for applications. Improvement via material innovation remains desirable and challenging. Herein,five one-dimensional conjugated coordination polymers were synthesized via the reaction between metal ions(Zn^(2+), Cu^(2+), Ni^(2+),Pt^(2+) and Pd^(2+)) and 2,5-diaminobenzene-1,4-dithiol(DABDT) and fabricated into RRAM devices. The as-fabricated ternary memories have relatively low threshold voltages(V_(th1):-1 to-1.4 V, V_(th2):-1.8 to-2.2 V). Their ternary device yields were improved from 24% to 56%. The first and the second resistance switches are interpreted by the space charge limited current(SCLC) and grain boundary depletion limited current(GBLC) modes, respectively. The Pd-DABDT, which is of planar structure,smaller band gap and better crystallinity than others, shows the best performance among these five polymers. Our work paves a simple and efficient way to optimize the performance of ternary RRAM devices employing one-dimensional hybrid materials. 展开更多
关键词 one-dimensional coordination polymer resistive random access memory TERNARY device yield low threshold VOLTAGES d-π CONJUGATION
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A three-dimensional k-ε-k_p model in curvilinear coordinates for sediment movement and bed evolution 被引量:2
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作者 SHEN YongMing1 & LIU Cheng2 1 State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116023, China 2 Pearl River Hydraulic Research Institute, Guangzhou 510611, China 《Science China(Technological Sciences)》 SCIE EI CAS 2009年第4期1090-1100,共11页
To aim at the substitution of the magnitude and direction of water flow movement near bed for those of bed load transport in solid-liquid two-phase one-fluid model, and to simulate the effect of secondary flow on tran... To aim at the substitution of the magnitude and direction of water flow movement near bed for those of bed load transport in solid-liquid two-phase one-fluid model, and to simulate the effect of secondary flow on transverse bed load transport in channel bends and the effect of bed slope on bed load trans- port in a better way, a three-dimensional k-ε-kp solid-liquid two-phase two-fluid model in curvilinear coordinates is solved numerically with a finite-volume method on an adaptive grid for studying wa- ter-sediment movements and bed evolution in a 120° channel bend. Numerical results show that the trajectories of solid-phase deviate from those of liquid-phase in the channel bend, and the deviation increases with the increase of the particle diameters. The calculated bed deformation by the k-ε-kp model is in better agreement with measured bed deformation than those by one-fluid model. It is proved that the k-ε-kp model can simulate the effect of secondary flow on lateral bed load transport with the higher accuracy than the one-fluid model. 展开更多
关键词 curvilinear coordinates THREE-dimensional k-ε-kp MODEL TWO-FLUID MODEL SOLID-LIQUID flows channel bend BED load BED EVOLUTION tra- jectory
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Hydrothermal Synthesis, Crystal Structure and Fluorescence Property of a Novel Coordination Polymer [Eu_2(C_6H_8O_4)_3(H_2O)_2]_n·n(4,4′-bpy)
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作者 董国义 窦军红 +3 位作者 葛世艳 林琳 郑一博 韦志仁 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第1期69-73,共5页
A novel coordination polymer [Eu2(C6H8O4)3(H2O)2]n?n(4,4?-bpy) (Mr = 928.51) was synthesized by the hydrothermal reaction of EuCl3?6H2O, adipic acid and 4,4?-bpy, and determined by elemental analysis, IR spectroscop... A novel coordination polymer [Eu2(C6H8O4)3(H2O)2]n?n(4,4?-bpy) (Mr = 928.51) was synthesized by the hydrothermal reaction of EuCl3?6H2O, adipic acid and 4,4?-bpy, and determined by elemental analysis, IR spectroscopy, thermal gravimetric analysis, single-crystal diffraction and fluorescence property. X-ray analysis reveals that a three-dimensional network has been formed between Eu3+ by carboxyl of adipic acid. The crystal is of orthorhombic, space group Pbcn with a = 21.870(7), b = 7.652(2), c = 19.624(6) ?, V = 3284.1(17) ?3, Z = 4, Dc = 1.878 g/cm3, μ = 3.854 mm-1, F(000) = 1824, R = 0.0345 and wR = 0.0565. The coordination polymer exhibits intensive red light under UV excitation at room temperature, which is attributed to the 5D0→7F2 transition of Eu(Ⅲ) ions. 展开更多
关键词 hydrothermal reaction three-dimensional coordination polymer crystal structure fluorescence property
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