检索结果-南通市图书馆

Pattern Structure of Deterministic Displacement in Random Porous Media with Dispersion Effect

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2002年第1期37卷 91-95页

作者： TIANJu－Ping yaokai－lun DepartmentofPhysics WuhanInstituteofScienceandTechnologyWuhan430073China DepartmentofPhysics HuazhongUniversityofScienceandTechnologyWuhan430074China

A new model - modelof random porous media degradation via several fluid displacing, freezing, and thawing cycles is introduced and investigated in this paper. The fluid transport is based on the deterministic method with dispersion effect. The result shows that the topology and the geometry of the porous media have a strong effect on displacement processes. The cluster size of viscous fingering (VF) pattern in percolation cluster increases with the increase of iteration parameter n. When iteration parameter n ≥ 10, VF pattern does not change with n. We find that the displacement fluid forms trapping regions in random porous media with dispersion effect. And the trapping regions will expand with the increasing of the iteration parameter n. When r (throat size) → 1 and n ≥ 5, the peak value of the distribution Nmat(r) increases as n increases, where Nmat(r) is the normalized distribution of throat sizes after different displacement-damages but before freezing. The peak value of the distribution Ninv(r) reaches a maximum when n ≥ 10 and r = 1, where Ninv(r) is the normalized distribution of the size of invaded throat. This result is different from invasion percolation. It is found that the sweep efficiency E increases along with the increasing of iteration parameter n and decreases with the network size L, and E has a minimum as L increases to the maximum size of Iattice. The VF pattern in percolation cluster has one frozen zone and one active zone.

关键词：随机多孔介质图样结构色散效应

Coexistence of Magnetism and Conductivity in Bis（ethylenediseleno） Tetrathiafulvalene （BEST） with Octahedral Anions Hexacyanoferrate （Ⅲ） and Nitroprusside

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第1期43卷 187-192页

作者： ZOUWei-Dong LIUZu—Li WUMing-Hu yaokai-lun DepartmentofPhysics HuazhongUniversityofScienceandTechnologyWuhan430074 China／／DepartmentofPhysics XianningTeachersCollegeXianning437005China DepartmentofPhysics HuazhongUniversityofScienceandTechnologyWuhan430074China DepartmentofPhysics XianningTeachersCollegeXianning437005China

Using an accurate density-function method, we explore the coexistence of the magnetism and conductivity in bis(ethylenediselena)-tetrathiafulvalene (BEST) with the paramagnetic hexacyanoferrate(Ⅲ) [Fe(CN)6]3-or the photochromic nitroprusside anion [Fe(CN)5NO]2-. The total and partial densities of states, and the atomic spin magnetic moments are calculated and discussed. It is found that the up- and down-spin total densities of states (DOS)are continuous in the vicinity of the Fermi level, there is overlap between the HOMO and LUMO in the up-spin subbands and the down-spin subbands, which reveals that these types of compounds have conductive properties. From the total and partial densities of states and atomic spin magnetic moments, it is shown that the spin magnetic moments of (BEST)4[Fe(CN)6] is mainly assembled at the iron atom and the cyanogen radical, and the spontaneous magnetic moments for (BEST)2[Fe(CN)5NO] come from iron atom, cyanogen and nitric oxide radical. To our best knowledge, it is the first theoretical study on the coexistence of the magnetism and conductivity of these compounds.

关键词： BEST DOS CN

Strong Ferromagnetic Coupling of {[Cu（Hpht）（N3）]·H2O}n with Simultaneous End-on Azido and Carboxylato Bridges： a First Principle Study

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第2期43卷 349-352页

作者： yaokai-lun ZUFeng-Xia LIUZu-Li ZOUWei-Dong DepartmentofPhysicsandStateKeyLabofLaserTechnology HuazhongUniversityofScienceandTechnologyWuhan430074China DepartmentofPhysicsandStateKeyLabofLaserTechnology HuazhongUniversityofScienceandTechnologyWuhan430074China／／InternationalCenterofMaterialsPhysicsTheChineseAcademyofSciencesShenyang110015 China

The compound {[Cu(Hpht)(N3)].H2O}n (Hpht = hydrogen phthalate) is formed by chains of copper atoms bridged simultaneously by syn-syn carboxylato and end-on azido bridges. Taking into account the large Cu-O(1)-C(7)bond angle of the single carboxylato bridge (131°), or the large Cu-N(11)-Cu bond angle of the azido bridge (111.9°),a moderately intrachain antiferromagnetic behavior should be expected for the compound. This paper is devoted to examining the apparently anomalous intrachain ferromagnetic behavior of {[Cu(Hpht)(Ns)].H2 O}n, using first principles within the fullpotential linearized augmented plane wave (FP-LAPW) method. The total energy, the density of states (DOS), and the spin distributions are obtained. The atomic spin distribution has been analyzed as resulting from the interplay of electron delocalization and spin polarization. The DOS reveals a surprisingly strong exchange interaction between the d type orbitals of the copper and the πr molecular orbitals of the two ligands.

关键词：铁磁耦合自旋偏振超交换作用量子效应半导体

ab initio Study of Electronic Structure and Magnetic Properties of a Novel N ＊Two-Dimensional Copper（II）-Radical Complex [Cu（NTTmPy）2（N3）2]n

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2004年第1期41卷 119-122页

作者： yaokai-lun WANGLi-Qiang LIUZu-Li ZOUWei-Dong LUOShi-Jun ZUFeng-Xia ZHULin DepaxtmentofPhysicsandStateKeyLabofLaserTechnology HuazhongUniversityofScienceandTechnologyWuhan430074ChinaInternationalCenterforMaterialsPhysicstheChineseAcademyofSciencesShenyang110015China DepartmentofPhysicsandStateKeyLabofLaserTechnology HuazhongUniversityofScienceandTechnologyWuhan430074China

The full-potential linearized augmented plane wave (FPLAPW) method with the generalized gradientapproximations (GGA) is applied to study the compound [Cu(NTTmPy)2(N3)2]n(NITmPy = 2 - (3' - PyridyX) -4, 4, 5, 5 - tetramethylimidazolin - 1 - oxyl - 3 - oxide). The total density of states (DOS) and the partial densityof states (pDOS) are calculated to explain the electronic and the magnetic properties of [Cu(NTTmPy)2(Na)2]n. It isfound that [Cu(NTTmPy)2(N3)2]n is stable in the ferromagnetic state and the magnetic moment of the molecule mainlycomes from the Cu atoms (0.518μB) with partial contribution from N, 0 atoms of nitronyl nitroxide radicals. Thereexist orbital hybridization between 3d orbital of Cu and p orbitals of N(1) (from pyridyl rings of the NITmPy ligands)and N(4) (from azido group) and the weak direct exchange interactions between Cu and 0 atoms of nitronyl *** addition, the bridging carbon atom (C(6)) carries a significant negative spin density (-O.019μB). The sign alternationof the magnetic moment along the pyridyl ring is obtained, which agrees with experiments.

关键词：电子结构有机磁铁铁磁体铜原子碳原子

I- VCurve Characterization of n +/p/p+ Silicon Solar Cell

在线全文

学校读者我要写书评

暂无评论

Semiconductor Photonics and Technology 1999年第4期5卷 226-228页

作者： MabroukGAbdrhman yaokai－lun 等 HuazhongUniversityofScience＆Technology Wuhan430074CHN HuazhongUniversityofScience＆Technology Wuhan43

The analysis of solar cell performance has been done by simulating the external I-V characteristics of n +/p/p + single crystal silicon solar cell under high light intensity and 1.5 air mass (AM). This method allows the maximization of solar cell efficiency. To fabricate low-cost n +/p/p + single crystal silicon solar cells, solid source of doped phosphorous and boron was used.

关键词：单晶硅太阳能电池效率伏安特性曲线

Multi-Axis Attention With Convolution Parallel Block for Organoid Segmentation

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1295-1297页

作者： Pengwei Hu Xun Deng Feng Tan lun Hu Xinjiang Technical Institute of Physics and Chemistry Chinese Academy of SciencesUrumqi 830011 University of Chinese Academy of Sciences Beijing 100049 Xinjiang Laboratory of Minority Speech and Language Information Processing Urumqi 830011China Merck KGaA Darmstadt 64293Germany

Dear Editor,This letter presents an organoid segmentation model based on multi-axis attention with convolution parallel *** adeptly captures dynamic dependencies within bright-field microscopy images,improving global ... 详细信息

关键词： letter convolution organo

Ergodicity of 3D Stochastic Burgers Equation

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第2期40卷 498-510页

作者： Zhao DONG Jiang lun WU Guo Li ZHOU RCSDS Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190P.R.China Department of Mathematics Computational FoundrySwansea UniversitySwansea SA18ENUK College of Mathematics and Statistics Chongqing UniversityChongqing 400044P.R.China

3D Burgers equation is an important model for *** is natural to expect the long-time behaviour for this hydrodynamics ***,there is no result about the long-time behaviour for this deterministic ***,if the system is perturbed by stochastic noise,we establish the existence and uniqueness of invariant measure for 3D stochastic Burgers equation.

关键词： 3D stochastic Burgers equations maximum principle ergodicity

Relationship between hydrogenation degree and pyrolysis performance of jet fuel

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第4期68卷 35-42页

作者： Qing Liu Tinghao Jia lun Pan Jijun Zou Xiangwen Zhang Key Laboratory for Green Chemical and Technology School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China Zhejiang Institute of Tianjin University Ningbo 315201China Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China

Understanding the relationship between the chemical composition and pyrolysis performance of endothermic hydrocarbon fuel(EHF) is of great significance for the design and optimization of advanced EHFs. In this work, the effect of deep hydrogenation on the pyrolysis of commercial RP-3 is *** with different hydrogenation degrees were obtained by the partially and completely catalytic hydrogenation and their pyrolysis performances were investigated using an apparatus equipped with an electrically heated tubular reactor. The results show that with the increase of hydrogenation degree, fuel conversion almost remains constant during the pyrolysis process(500-650°C, 4 MPa);however, the heat sink increases slightly, and the anti-coking performance significantly improves, which are highly related to their H/C ratios. Detailed characterisations reveal that the difference of the pyrolysis performance can be ascribed to the content of aromatics and cycloalkanes: the former are prone to initiate secondary reactions to form coking precursors, while the latter could act as the hydrogen donor and release hydrogen, which will terminate the radical propagation reactions and suppress the coke deposition. This work should provide the guidance for upgrading EHFs by modulating the composition of EHFs.

关键词： RP-3 Fuel Pyrolysis Hydrogenation Deposition

Optimal Shape Factor and Fictitious Radius in the MQ-RBF:Solving Ill-Posed Laplacian Problems

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第6期139卷 3189-3208页

作者： Chein-Shan Liu Chung-lun Kuo Chih-Wen Chang Center of Excellence for Ocean Engineering Taiwan Ocean UniversityKeelung202301TaiwanChina Department of Mechanical Engineering National United UniversityMiaoli36063TaiwanChina

To solve the Laplacian problems,we adopt a meshless method with the multiquadric radial basis function(MQRBF)as a basis whose center is distributed inside a circle with a fictitious radius.A maximal projection technique is developed to identify the optimal shape factor and fictitious radius by minimizing a merit function.A sample function is interpolated by theMQ-RBF to provide a trial coefficient vector to compute the merit *** can quickly determine the optimal values of the parameters within a preferred rage using the golden section search *** novel method provides the optimal values of parameters and,hence,an optimal MQ-RBF;the performance of the method is validated in numerical ***,nonharmonic problems are transformed to the Poisson equation endowed with a homogeneous boundary condition;this can overcome the problem of these problems being *** optimal MQ-RBF is extremely *** further propose a novel optimal polynomial method to solve the nonharmonic problems,which achieves high precision up to an order of 10^(−11).

关键词： Laplace equation nonharmonic boundary value problem Ill-posed problem maximal projection optimal shape factor and fictitious radius optimal MQ-RBF optimal polynomial method