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Research on Visualization and Interactive Design of Plant Configuration Virtual Reality in the Context of Digitalization
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作者 Qiufan Xie 《Journal of Architectural Research and Development》 2024年第3期53-62,共10页
This study aims to explore the application of digital technology in landscape design,focusing on the research of virtual reality visualization and interactive design in the process of plant configuration.Through an in... This study aims to explore the application of digital technology in landscape design,focusing on the research of virtual reality visualization and interactive design in the process of plant configuration.Through an in-depth analysis of digital technology,the study outlines its important role in landscape design,especially in the application of plant configuration.The current application status of virtual reality technology in landscape design is discussed,as well as how interactive design can enhance user experience and participation.Furthermore,the achievements and challenges of digital technology in landscape design are summarized.Finally,it proposes future research directions and suggestions,aiming to provide new ideas and methods for practice and research in the field of landscape design and promote the further application and development of digital technology in landscape design. 展开更多
关键词 lization Plant configuration Virtual reality VISUALIZATION interactive design
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Analytic variationally optimized internally orthogonalized modified Laguerre orbitals in accurate atomic configuration interaction calculation 被引量:2
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作者 熊庄 Bacalis N C 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第5期992-997,共6页
An analytic configuration interaction method based on variationally optimized internally orthogonalized modified Laguerre orbitals is presented. We have developed the corresponding computer code. For application, we s... An analytic configuration interaction method based on variationally optimized internally orthogonalized modified Laguerre orbitals is presented. We have developed the corresponding computer code. For application, we study the 1s2s ^1S isoelectronic sequence from helium to neon, and compare with other methods. By taking into account the Eekart upper-bound theorem, we obtained more accurate and more intuitively understandable results than Hartree-Fock and multi-configuration Hartree-Fock reported results. 展开更多
关键词 atomic excited states analytic basis function configuration interaction variational computation
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Multireference configuration interaction potential curve and analytical potential energy function of the ground and low-lying excited states of CdSe 被引量:1
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作者 高峰 杨传路 +1 位作者 胡振彦 王美山 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第12期3668-3674,共7页
The potential energy curves (PECs) of the ground state (^3∏) and three low-lying excited states (^1∑, ^3∑,^1∏) of CdSe dimer have been studied by employing quasirelativistic effective core potentials on the ... The potential energy curves (PECs) of the ground state (^3∏) and three low-lying excited states (^1∑, ^3∑,^1∏) of CdSe dimer have been studied by employing quasirelativistic effective core potentials on the basis of the complete active space self-consistent field method followed by multireference configuration interaction calculation. The four PECs are fitted to analytical potential energy functions using the Murrel-Sorbie potential function. Based on the PECs, the vibrational levels of the four states are determined by solving the Schrodinger equation of nuclear motion, and corresponding spectroscopic constants are accurately calculated. The equilibrium positions as well as the spectroscopic constants and the vibrational levels are reported. By our analysis, the ^3∏ state, of which the dissociation asymptote is Cd(^1S) + Se(^3p), is identified as a ground state of CdSe dimer, and the corresponding dissociation energy is estimated to be 0.39eV. However, the first excited state is only 1132.49cm^-1 above the ground state and the ^3∑ state is the highest in the four calculated states. 展开更多
关键词 potential energy curve multireference configuration interaction spectroscopic con- stants vibrational levels
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Relativistic Configuration Interaction Calculations on Kα X-Ray Satellites of Manganese 被引量:1
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作者 LI Hui-Li LI Ping CHENG Zhang MA Hai-Rong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第1期217-220,共4页
With contributions from Breit interaction, quantum electrodynarnics (QED) corrections and nuclear mass corrections to the initial and final levels are taken into account. The transition energies, transition probabil... With contributions from Breit interaction, quantum electrodynarnics (QED) corrections and nuclear mass corrections to the initial and final levels are taken into account. The transition energies, transition probabilities, and absorption oscillator strengths of Kα x-ray from Mn XVII to Mn XXIV have been calculated by using relativistic configuration interaction (RCI) and multi-configuration Dirac Fock (MCDF) method in the active interaction approach. Compared with the only available experimental transition data on He-like and Li-like manganese, the present results are in good agreement with them, and the rest of transition data of the present results are new ones. These wide range data can provide useful parameters for the study of the manganese plasma. 展开更多
关键词 TRANSITION highly ionized Mn relativistic configuration interaction multi-configuration DiracFock method
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Explicitly correlated configuration interaction investigation on low-lying states of SiO^+ and SiO
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作者 Rui Li Gui-Ying Liang +3 位作者 Xiao-He Lin Yu-Hao Zhu Shu-Tao Zhao Yong Wu 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第4期157-164,共8页
SiO^+ and SiO, which play vital roles in astrophysics and astrochemistry, have long attracted considerable attention.However, accurate information about excited states of SiO^+ is still limited. In this work, the stru... SiO^+ and SiO, which play vital roles in astrophysics and astrochemistry, have long attracted considerable attention.However, accurate information about excited states of SiO^+ is still limited. In this work, the structures of 14 Λ–S states and 30? states of SiO^+ are computed with explicitly correlated configuration interaction method. On the basis of the calculated potential energy curves of those Λ–S states and ? states, the spectroscopic constants of bound states are evaluated, which are in good agreement with the latest experimental results. The predissociation mechanism of B^2Σ^+ state is illuminated with the aid of spin–orbit coupling matrix elements. On the basis of the calculated potential energy curves and transition dipole moments, the radiative lifetime for each of low-lying vibrational states B^2Σ^+and A^2Π is estimated. The laser cooling scheme of SiO^+ is proposed by employing B^2Σ^+–X^2Σ^+ transition. Finally, the vertical ionization energy values from SiO(X^1Σ^+) to ionic states: SiO^+ , X^2Σ^+, B^2Σ^+, and A^2Π are calculated, which agree well with experimental measurements. 展开更多
关键词 SiO+ explicitly CORRELATED configuration interaction transition DIPOLE MOMENT IONIZATION energy
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Iterative Multireference Configuration Interaction
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作者 Wen-yan Zhang Fei-wu Chen 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2019年第6期701-707,I0002,I0003,共9页
Iterative multireference configuration interaction (IMRCI) is proposed. It is exploited to compute the electronic energies of H2O and CH2(singlet and triplet states) at equilibrium and non-equilibrium geometries. The ... Iterative multireference configuration interaction (IMRCI) is proposed. It is exploited to compute the electronic energies of H2O and CH2(singlet and triplet states) at equilibrium and non-equilibrium geometries. The potential energy curves of H2O, CH2(singlet and triplet states) and N2 have also been calculated with IMRCI as well as the M?ller Plesset perturbation theory (MP2, MP3, and MP4), the coupled cluster method with single and double substitutions (CCSD), and CCSD with perturbative triples correction (CCSD(T)).These calculations demonstrate that IMRCI results are independent of the initial guess of configuration functions in the reference space and converge quickly to the results of the full configuration interaction. The IMRCI errors relative to the full configuration interaction results are at the order of magnitude of 10-5 hartree within just 2-4 iterations. Further,IMRCI provides an efficient way to find on the potential energy surface the leading electron configurations which, as correct reference states, will be very helpful for the single-reference and multireference theoretical models to obtain accurate results. 展开更多
关键词 Multireference configuration interaction configuration interaction Full configuration interaction Iterative multireference configuration interaction
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Multi-reference configuration-interaction calculations on multiply charged ions of carbon monosulfide
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作者 闫冰 张玉娟 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第2期159-165,共7页
The potential energy curves for neutrals and multiply charged ions of carbon monosulfide are computed with highly correlated multi-reference configuration interaction wavefunctions.The correlations of inner-shell elec... The potential energy curves for neutrals and multiply charged ions of carbon monosulfide are computed with highly correlated multi-reference configuration interaction wavefunctions.The correlations of inner-shell electrons with the scalar relativistic effects are included in the present computations.The spectroscopic constants,dissociation energies,ionization energies for ground and low-lying excited states together with corresponding electronic configurations of ions are obtained,and a good agreement between the present work and existing experiments is found.No theoretical evidence is found for the adiabatically stable CSq+(q〉2) ions according to the present ab initio calculations.The calculated values for 1st-6th ionization energies are 11.25,32.66,64.82,106.25,159.75,and 224.64 eV,respectively.The kinetic energy release data of fragments are provided by the present work for further experimental comparisons. 展开更多
关键词 potential energy curve spectroscopic constants multi-reference configuration interaction kinetic energy release
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AB INITIO CONFIGURATION INTERACTION STUDY OF THE ELECTRONIC AND GEOMETRIC STRUCTURE OF MIXED NEUTRAL AND CATIONIC BLi_k(k=1~7)CLUSTERS
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作者 Hua Bei ZHANG An Min TIAN and Guo Sen YAN(Department of Chemistry,Sichuan University,Chengdu 610064) 《Chinese Chemical Letters》 SCIE CAS CSCD 1994年第11期995-998,共4页
The geometries of mixed neutral and cationic BLik(k=1-7)clusters have ben determined with energy gradient method.The correlation energy is considered with the single-double configuration interaction(CISD).The boron at... The geometries of mixed neutral and cationic BLik(k=1-7)clusters have ben determined with energy gradient method.The correlation energy is considered with the single-double configuration interaction(CISD).The boron atom B takes the central position in the most stable geometries of all clusters studied except in the neutral BLi3 cluster.The binding energies per atom and the second differences in energies are discussed. 展开更多
关键词 AB INITIO configuration interaction ELECTRONIC OF THE STUDY BLi_k AND
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Electronic States of Difluorocarbene Calculated by Multireference Configuration Interaction Method
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作者 孙二平 任廷琦 +4 位作者 刘启鑫 苗泉 张进娟 徐海峰 闫冰 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第2期17-21,共5页
We investigate the geometries and energies of seven electronic states X-1A1, A1B1, a-3B1, B-1A2,b-3A2, C1B2 and c-3B2 of CF2 carbene using internally contracted multireference configuration interaction methods includi... We investigate the geometries and energies of seven electronic states X-1A1, A1B1, a-3B1, B-1A2,b-3A2, C1B2 and c-3B2 of CF2 carbene using internally contracted multireference configuration interaction methods including Davidson correction (icMRCIq-Q) with different basis sets aug-cc-pVXZ (X=T, Q, 5). For the first time, the potential energy curves of electronic states of CF2 related icMRCI+Q/aug-cc-pVTZ level. The ab initio results will and dynamics of electronic states of CF2 radical. to the lowest dissociation limit are calculated at the further increase our understanding of the structures 展开更多
关键词 of on in ET HAVE been CF Electronic States of Difluorocarbene Calculated by Multireference configuration interaction Method by were
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Examination of Potential Energy Curves of CFCl by Multi-reference Configuration Interaction Method
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作者 孙二平 刘启鑫 +3 位作者 任廷琦 单石敏 徐海峰 闫冰 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第12期43-46,共4页
We give a detailed examination of potential energy curves of the singlet and triplet states of CFC1 correlated with the lowest three dissociation limits. The calculations are carried out at the internally contracted m... We give a detailed examination of potential energy curves of the singlet and triplet states of CFC1 correlated with the lowest three dissociation limits. The calculations are carried out at the internally contracted multi- reference configuration interaction/cc-pV(T+d)Z level with the other two geometric parameters fixed at the state equilibrium conformation. The vertical transition energy, the oscillator strength, the main configuration and the electron transition are also investigated at the same level. 展开更多
关键词 Examination of Potential Energy Curves of CFCl by Multi-reference configuration interaction Method CL LENGTH CFC
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Quantum-Mechanical Information Content of Multiples Hartree-Fock Solutions. The Multi-Reference Hartree-Fock Configuration Interaction Method
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作者 Luiz Augusto Carvalho Malbouisson Antonio Moreira de Cerqueira Sobrinho Micael Dias de Andrade 《Journal of Modern Physics》 2014年第7期543-548,共6页
The Hartree-Fock equation is non-linear and has, in principle, multiple solutions. The ωth HF extreme and its associated virtual spin-orbitals furnish an orthogonal base Bω of the full configuration interaction spac... The Hartree-Fock equation is non-linear and has, in principle, multiple solutions. The ωth HF extreme and its associated virtual spin-orbitals furnish an orthogonal base Bω of the full configuration interaction space. Although all Bω bases generate the same CI space, the corresponding configurations of each Bω base have distinct quantum-mechanical information contents. In previous works, we have introduced a multi-reference configuration interaction method, based on the multiple extremes of the Hartree-Fock problem. This method was applied to calculate the permanent electrical dipole and quadrupole moments of some small molecules using minimal and double, triple and polarized double-zeta bases. In all cases were possible, using a reduced number of configurations, to obtain dipole and quadrupole moments in close agreement with the experimental values and energies without compromising the energy of the state function. These results show the positive effect of the use of the multi-reference Hartree-Fock bases that allowed a better extraction of quantum mechanical information from the several Bω bases. But to extend these ideas for larger systems and atomic bases, it is necessary to develop criteria to build the multireference Hartree-Fock bases. In this project, we are beginning a study of the non-uniform distribution of quantum-mechanical information content of the Bω bases, searching identify the factors that allowed obtain the good results cited 展开更多
关键词 Multiple HARTREE-FOCK SOLUTIONS QUANTUM MECHANICAL INFORMATION Content MULTI-REFERENCE Hartre-Fock configuration interaction Method
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Validation of the Ability of Full Configuration Interaction Quantum Monte Carlo for Studying the 2D Hubbard Model
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作者 贠素君 董铁矿 祝世宁 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第8期1-5,共5页
To validate the ability of full configuration interaction quantum Monte Carlo (FCIQMC) for studying the 2D Hubbard model near half-filling regime, the ground state energies of a 4×44×4 square lattice syste... To validate the ability of full configuration interaction quantum Monte Carlo (FCIQMC) for studying the 2D Hubbard model near half-filling regime, the ground state energies of a 4×44×4 square lattice system with various interaction strengths are calculated. It is found that the calculated results are in good agreement with those obtained by exact diagonalization (i.e., the exact values for a given basis set) when the population of psi particles (psips) is higher than the critical population required to correctly sample the ground state wave function. In addition, the variations of the average computational time per 20 Monte Carlo cycles with the coupling strength and the number of processors are also analyzed. The calculated results show that the computational efficiency of an FCIQMC calculation is mainly affected by the total population of psips and the communication between processors. These results can provide useful references for understanding the FCIQMC algorithm, studying the ground state properties of the 2D Hubbard model for the larger system size by the FCIQMC method and using a computational budget as effectively as possible. 展开更多
关键词 QMC Validation of the Ability of Full configuration interaction Quantum Monte Carlo for Studying the 2D Hubbard Model FCI
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A Structured Mesh Euler and Interactive Boundary Layer Method for Wing/Body Configurations
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作者 李杰 周洲 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第1期19-27,共9页
To compute transonic flows over a complex 3D aircraft configuration, a viscous/inviscid interaction method is developed by coupling an integral boundary-layer solver with an Eluer solver in a "semi-inverse" manner. ... To compute transonic flows over a complex 3D aircraft configuration, a viscous/inviscid interaction method is developed by coupling an integral boundary-layer solver with an Eluer solver in a "semi-inverse" manner. For the turbulent boundary-layer, an integral method using Green's lag equation is coupled with the outer inviscid flow. A blowing velocity approach is used to simulate the displacement effects of the boundary layer. To predict the aerodynamic drag, it is developed a numerical technique called far-field method that is based on the momentum theorem, in which the total drag is divided into three component drags, i.e. viscous, induced and wave-formed. Consequently, it can provide more physical insight into the drag sources than the often-used surface integral technique. The drag decomposition can be achieved with help of the second law of thermodynamics, which implies that entropy increases and total pressure decreases only across shock wave along a streamline of an inviscid non-isentropic flow. This method has been applied to the DLR-F4 wing/body configuration showing results in good agreement with the wind tunnel data. 展开更多
关键词 viscous/inviscid interaction far-field drag prediction transonic flow wing/body configuration
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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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An Extended Cu(Ⅱ) Complex Structure Sustained by Hydrogen Bonding and C-H…π Interactions 被引量:1
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作者 吴刚 王小锋 +2 位作者 愈力 张婷 张敏 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第9期1337-1342,共6页
The title complex [Cu(L1)(L2)(H2O)]·H2O(1,HL1 = N-(imino(pyridin-2-yl)me-thyl)picolinamidine),HL2 = salicylic acid) has been obtained by volatilization method with L1 prepared from 2,4,6-tripyridyl-1... The title complex [Cu(L1)(L2)(H2O)]·H2O(1,HL1 = N-(imino(pyridin-2-yl)me-thyl)picolinamidine),HL2 = salicylic acid) has been obtained by volatilization method with L1 prepared from 2,4,6-tripyridyl-1,3,5-triazine in situ.1 was fully characterized by single-crystal X-ray diffraction,elemental analysis and FT-IR.This complex exhibits a three-dimensional frame-work constructed through hydrogen bonding and C-H···π stacking interactions.The cyclic voltametric behavior of complex 1 was also investigated.1 belongs to the monoclinic system,space group P21/c with a = 15.112(5),b = 7.115(2),c = 19.899(6) ,β = 112.32°,V = 1979.4(11) 3,Mr = 460.94,Dc = 1.540 g/cm3,F(000) = 948,μ = 1.146 mm-1,Z = 4,the final R = 0.0612 and wR = 0.1813 for 2510 observed reflections with I 2σ(I). 展开更多
关键词 hydrogen bond c-h···π interaction cyclic voltammetry
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STABILITY OF STEADY MULTI-WAVE CONFIGURATIONS FOR THE FULL EULER EQUATIONS OF COMPRESSIBLE FLUID FLOW 被引量:2
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作者 Gui-Qiang G.CHEN Matthew RIGBY 《Acta Mathematica Scientia》 SCIE CSCD 2018年第5期1485-1514,共30页
We are concerned with the stability of steady multi-wave configurations for the full Euler equations of compressible fluid flow. In this paper, we focus on the stability of steady four-wave configurations that are the... We are concerned with the stability of steady multi-wave configurations for the full Euler equations of compressible fluid flow. In this paper, we focus on the stability of steady four-wave configurations that are the solutions of the Riemann problem in the flow direction, consisting of two shocks, one vortex sheet, and one entropy wave, which is one of the core multi-wave configurations for the two-dimensional Euler equations. It is proved that such steady four-wave configurations in supersonic flow are stable in structure globally, even under the BV perturbation of the incoming flow in the flow direction. In order to achieve this, we first formulate the problem as the Cauchy problem (initial value problem) in the flow direction, and then develop a modified Glimm difference scheme and identify a Glimm-type functional to obtain the required BV estimates by tracing the interactions not only between the strong shocks and weak waves, but also between the strong vortex sheet/entropy wave and weak waves. The key feature of the Euler equations is that the reflection coefficient is always less than 1, when a weak wave of different family interacts with the strong vortex sheet/entropy wave or the shock wave, which is crucial to guarantee that the Glimm functional is decreasing. Then these estimates are employed to establish the convergence of the approximate solutions to a global entropy solution, close to the background solution of steady four-wave configuration. 展开更多
关键词 STABILITY multi-wave configuration vortex sheet entropy wave shock wave BV perturbation full Euler equations steady wave interactions Glimm scheme
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Assessment of Control Configurations for a General Heat Integrated Distillation Column 被引量:2
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作者 黄克谨 钱积新 +2 位作者 中岩勝 中根■ 高松武一郎 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2000年第4期339-346,共8页
The assessment of control configurations for an ideal heat integrated distillation column incorporated with an overhead condenser and a bottom reboiler (general HIDiC) is addressed in this work. It is found that doubl... The assessment of control configurations for an ideal heat integrated distillation column incorporated with an overhead condenser and a bottom reboiler (general HIDiC) is addressed in this work. It is found that double ratio control configuration, (L/D, V/B), is still the best one among all the possibilities. The control configuration,(Pr - Ps, q), appears to be a feasible one for the general HIDiC and the pressure difference between the rectifying and the stripping sections and feed thermal condition are expected to be consistent manipulative variables for the process. The performance of the general HIDiC can be substantially improved by employing effective multivariable control algorithms. 展开更多
关键词 DISTILLATION control configuration interaction disturbance rejection closed-loop simulation
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Transitional wave configurations between Type Ⅲ and Type Ⅳ oblique-shock/bow-shock interactions 被引量:2
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作者 Jun PENG Shuai LI +3 位作者 Fan YANG Mingyue LIN Guilai HAN Zongmin HU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第3期96-106,共11页
The interactions of oblique/bow shock waves are the key flow phenomena restricting the design and aerothermodynamic performance of high-speed vehicles.Type Ⅲ and Type Ⅳ Shock/Shock Interactions(SSIs)have been extens... The interactions of oblique/bow shock waves are the key flow phenomena restricting the design and aerothermodynamic performance of high-speed vehicles.Type Ⅲ and Type Ⅳ Shock/Shock Interactions(SSIs)have been extensively investigated,as such interactions can induce abnormal aerodynamic heating problems in hypersonic flows of vehicles.The transition process between these two distinct types of shock/shock interactions remains unclear.In the present study,a subclass of shock/shock interaction configuration is revealed and defined as Type Ⅲa.Type Ⅲa interaction can induce much more severe aerodynamic heating than a Type Ⅳ interaction which was ever reported to be the most serious in literature.The intense aerodynamic heating observed in this configuration highlights a new design point for the thermal protection system of hypersonic vehicles.A secondary Mach interaction between shock waves in the supersonic flow path of a Type Ⅲ configuration is demonstrated to be the primary mechanism for such a subclass of shock/shock interaction configuration. 展开更多
关键词 Shock interactions Transitional configuration Aerodynamic heating Shear layer Mach interaction
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Fluid-Structure Interaction Modeling of the Living Artery: Based on the Zero-Pressure Status and the Anisotropic Hyperelastic Constitutive Model
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作者 Dongliang Zhao Wenchang Tan 《医用生物力学》 EI CAS CSCD 北大核心 2019年第A01期107-108,共2页
Vascular diseases such as aneurysm,hemadostenosis,aortic dissection are the primary causes of people’s death around world.As a result,it is significant to improve our knowledge about them,which can help to treat the ... Vascular diseases such as aneurysm,hemadostenosis,aortic dissection are the primary causes of people’s death around world.As a result,it is significant to improve our knowledge about them,which can help to treat the disease.Measuring the hemodynamic factor like the blood pressure,the wall shear stress(WSS)and the oscillatory shear index(OSI)is,however,still beyond the capabilities of in-vivo measurement techniques.So the use of mathematical models and numerical simulations for the studies of the blood flow in arteries and,in general,of the cardiovascular system,both in physiological and pathological conditions,has received an increasing attention in the biomedical community during the last two decades.Indeed,such studies aims at enhancing the current knowledge of the physiology of the cardiovascular system,as well as providing reliable tools for the medical doctors to predict the natural course of pathologies and,possibly,the occurrence of cardiovascular accidents.The computational vascular fluid-structure interaction(FSI)methodology is a numerical simulation method which is used to explain the hemodynamic factors.The WSS on the luminal wall and the mechanical stress in the vascular wall are directly related to the location of the lesion,and the blood flow strongly interacts with the vascular wall motion.The arterial wall continually adapts to the charge of its mechanical environment(due to,for example,growth,atrophy,remodelling,repair,ageing,and disease)and consequently undergoes several irreversible processes.Primary acute mechanisms of vascularFSI numerical simulation seem to be associated with(1)the arterial histology and the patient-specific complex geometry,(2)the typical mechanical properties of the layer,(3)properties of the blood is assumed as Newtonian fluid or non-Newtonian fluid based on the scale ofthe diameter of a vessel,(4)residual stress in the zero-pressure configuration.The arterial system naturally function under permanent physiological loading conditions.Fung defined the residual stress and measured the opening angle which varies greatly along the aortic tree.Consequently,most of these systems never experience a stress-free state in their’service life’,so a stress and strain fields are present in any in vivo obtained patientspecific cardiovascular geometry.The residual stress always be ignored in FSI simulation or be assumed to equal zero,and the vivo patient-specific artery geometry is assumed as zero-pressure configuration.To define the in vivo stress state of artery,an inverse problem needs to be solved:the undeformed shape of a body or its stress state in its deformed state needs to be determined given the deformed configuration and the loads causing this deformation.The modular inverse elastostatics method is used to resolve the pressure-induced stress state for in vivo imaging based on cardiovascular modeling proposed by Peirlinck.Here,we build a living vessel FSI model based on 4 key factors.In order to get the universal simulation results,we focus on idealized geometries of the vessel that represent healthy(physiological)conditions of the cerebral vasculature.Blood can be assumed as the Newtonian fluid at this scale.The anisotropic hyperelastic constitutive law(Gasser-Holzapfel-Ogden)is used in zero-pressure configuration.Afterwards,we propose the material parameters for the different constitutive models and the computational configurations.We demonstrate the importance of introducing the residual stress into vascular blood flow modeling by performing a comparing zero-pressure configuration and no-resistance configuration.We get the conclusion that the zero-pressure status model has smaller displacement and larger stress distribution compared with no-resistance stress model.Hence,the methodology presented here will be particularly useful to study the mechanobiological processes in the healthy and diseased vascular wall. 展开更多
关键词 fluid structure interaction zero-pressure configuration ANISOTROPIC HYPERELASTIC CONSTITUTIVE LAW
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FATIGUE DISLOCATION CONFIGURATIONS IN HEXAGONAL ZIRCALOY-4
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作者 Xiao Lin(Institute of Engineering Mech., Xi’an Jiaotong University, Xi’an, China, 710049)Gu Haicheng(Institute for Strength of Metals, Xi’an Jiaotong University, Xi’an, China, 710049) 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1996年第2期122-125,共4页
Fatigue dislocation configurations of Zircaloy-4 at 470℃×1h stress-relieved condition and 620℃×1h recrystallized condition were analyzed using TEM. Theresults show that: {1 0 1 0} prismatic slip is the pri... Fatigue dislocation configurations of Zircaloy-4 at 470℃×1h stress-relieved condition and 620℃×1h recrystallized condition were analyzed using TEM. Theresults show that: {1 0 1 0} prismatic slip is the primary deformation mode at RT. Prismatic and pyramidal slips are activated simultaneously at 400℃. The typicalsubstructure is the elongated dislocation lines at RT; whereas at 400℃, it is rectangularcells in stress-relieved specimens, and elongated cells plus dipole perpendicular cellboundary in recrystallized specimens. The relationship map among dislocation configuration, test temperature and cyclic strain range is established, finally. 展开更多
关键词 Zircaloy (trademark) fatigue (materials) dislocations (materials) configuration interaction slip
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