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Underground Space 2024年第1期14卷 219-238页

作者： Fayun Liang Zhuwei Jiang Qiang Yuan Lin Li Rulu Wang Department of Geotechnical Engineering Tongji UniversityShanghai 200092China School of Highway Chang’an UniversityXi’an 710064China Shanghai Shentong Metro Group Limited Maintenance Center Shanghai 20070China

The surcharge load at the ground surface inevitably breaks the original equilibrium state between the underneath tunnel and the surrounding soil,which will impact the service performance of a subway *** paper presents a novel semi-analytical approach for assessing the time-dependent,longitudinal responses of a subway tunnel in soft soil strata induced by the surcharge *** solution is developed based on the framework of the classical"two-stage method"but innovatively incorporates the effects of ground stratification,the consolidation process,and the longitudinal stiffness reduction of the ***’s poroelastic theory in conjunction with the Laplace-Fourier transform technique is selected to model the deformation of the stratified ground,while the Timoshenko beam on a Pasternak foundation is employed to model the mechanical responses of the *** proposed semi-analytical solution is validated not only by comparison with benchmark solutions and a finite element model,but also by predicting a well-documented field *** analyses are conducted to investigate the effects of the elastic modulus and the permeability coefficient of the stratified ground on the longitudinal responses of the *** is expected that the proposed solution can serve as a useful tool for evaluating the effects of the surcharge load on the longitudinal responses of a subway tunnel.

关键词： time-dependent Longitudinal responses Stratified ground Subway tunnels Ground surface surcharge Consolidation

time-dependent density-functional theory for open electronic systems

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Science China Chemistry 2014年第1期57卷 26-35页

作者： ZHENG Xiao WANG RuLin Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Department of Physics University of Science and Technology of China

time-dependent density-functional theory(TDDFT)has been successfully applied to predict excited-state properties of isolated and periodic ***,it cannot address a system coupled to an environment or whose number of electrons is not *** tackle these problems,TDDFT needs to be extended to accommodate open *** paper provides a comprehensive account of the recent developments of TDDFT for open systems(TDDFT-OS),including both theoretical and practical *** practicality and accuracy of a latest TDDFT-OS method is demonstrated with two numerical examples:the time-dependent electron transport through a series of quasi-one-dimensional atomic chains,and the real-time electronic dynamics on a two-dimensional graphene *** advancement of TDDFT-OS may lead to promising applications in various fields of chemistry,including energy conversion and heterogeneous catalysis.

关键词： time-dependent density functional theory,real-time electronic dynamics,hierarchical equations of motion

time-dependent treatment of intramolecular energy transfer for HeICl complex

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Chinese Journal of Chemistry 1997年第3期15卷 218-224页

作者： Zhao, X Bu, YX Wu, AL Guan, DR SHANDONG NORMAL UNIV DEPT PHYSJINAN 250014SHANDONGPEOPLES R CHINA

The time-dependent golden wave packet method has been used for calculating the decay widths of vibrational predissociation for HeICl complex in the B state with total angular momentum J=0. This is a good example of intramolecular energy transfer, We examine the dependence of the final rotational distribution (partial decay width) of ICI fragment an the stretching excitation. It is found that computed final rotational distributions are weakly dependent on the vibrational level being excited. Unlike the smoothly varying rotational distribution for lower initial vibrational levels, for higher initial vibrational levels the rotational distribution indicates the very pronounced oscillatory structure. The analysis of the rotational distribution as a function of propagation time reveals the predominant role of the final states interaction in determining the final rotational distribution.

关键词： vibrational predissociation time-dependent wave-packet propagation

time-dependent behaviour of the Callovo-Oxfordian claystone-concrete interface

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第1期12卷 89-101页

作者： Eleni Stavropoulou Matthieu Briffaut Frédéric Dufour Guillaume Camps Univ.Grenoble Alpes CNRSGrenoble INP3SRF-38000GrenobleFrance Agence Nationale pour la gestion des Déchets Radioactifs(Andra) Chatenay-MalabryFrance

In the context of the Cigeo project,the French National Radioactive Waste Management Agency(Andra)is studying the behaviour of a deep geological facility for radioactive waste deposit in the CallovoOxfordian(COx)*** assessment of durability of this project requires the prediction of irreversible strain over a large time *** mechanical interaction of the host rock and the concrete support of tunnels must be investigated to ensure the long-term sustainability of the *** instantaneous and time-dependent behaviour of the claystone-concrete interface is experimentally investigated with direct shear tests and long-duration shear tests of a few *** mechanical and structural state of the claystone which is affected after interaction with concrete reflects to the response of the claystone-concrete interface,and thus different types of COx claystone-concrete interfaces are *** delayed deformation of the interface is found to be linked to the level of the normal loading and the loading history while a different response of the interface was observed from the short-and long-duration tests,indicating a possible progressive modification of interface under long-duration loadings.

关键词： Callovo-Oxfordian(COx)claystone Interfaces time-dependent behaviour

time-dependent relativistic density functional study of Yb and YbO

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Science China Chemistry 2009年第11期52卷 1945-1953页

作者： XU WenHua ZHANG Yong LIU WenJian Beijing National Laboratory for Molecular Sciences Institute of Theoretical and Computational ChemistryState Key Laboratory of Rare Earth Materials Chemistry and ApplicationsCollege of Chemistry and Molecular Engineeringand Center for Computational Science and EngineeringPeking UniversityBeijing 100871China

The low-lying electronic states of Yb and YbO are investigated by using time-dependent relativistic density functional theory,which is based on the newly developed exact two-component Hamiltonian resulting from symmetrized elimination of the small *** nature of the excited states is analyzed by using the full molecular *** calculated results support the previous experimental assignment of the ground and excited states of YbO.

关键词： lanthanide compound excited states f-orbital transitions time-dependent relativistic density functional theory exact two-component Hamiltonian

time-dependent wave packet approach to the pulse delay effect upon RbI photoelectron spectrum

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Science China Chemistry 2006年第3期49卷 214-218页

作者： LIU Chunhua MENG Qingtian ZHANG Qinggang College of Physics and Electronics Shandong Normal University Jinan 250014 China College of Physics and Electronics Shandong Normal University Jinan 250014 China College of Physics and Electronics Shandong Normal University Jinan 250014 China

The time-resolved photoelectron spectrum (TRPES) of Rbl molecule is simulatedusing the time-dependent wave-packet method. Both the normal three-photon ionization process andauto-ionization process are involved in the simulation. The calculated results show that the changeof delay time will influence the shape of the photoelectron spectrum (PES), and the influence issubstantially due to the existence of the crossing between excited states and the strong laser fieldwhich will change the position of relevant curves.

关键词： time-dependent wave packet method, multiphoton ionization (MPI), time-resolved photoelectron spectrum (TRPES), auto-ionization.

Developing an Instantaneous Response Surface Method t-IRS for time-dependent Reliability Analysis

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Acta Mechanica Solida Sinica 2019年第4期32卷 446-462页

作者： Junxiang Li Jianqiao Chen Junhong Wei Xiaosheng Zhang Ben Han Department of Mechanics Huazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment Wuhan 430074China

In practical engineering, many uncertain factors in loading or degradation of material properties may vary with time. Stochastic process modeling constitutes a suitable approach for describing these time-dependent uncertainties. By adopting this approach, however, the timedependent reliability calculation is a great challenge owing to the complexity and the huge computational burden. This paper presents a new instantaneous response surface method t-IRS for time-dependent reliability analysis. Different from the adaptive extreme response surface approach, the proposed method does not need to build and update surrogate models separately at each time node. It first uses the expansion optimal linear estimation method to discretize the stochastic processes into a set of independent standard normal variables together with some deterministic functions of time. time is then treated as an independent one-dimensional variable. Next, initial samples are generated by Latin hypercube sampling, and the corresponding response values are calculated and utilized to construct an instantaneous response surrogate model of the Kriging type. The active learning method is applied to update the Kriging surrogate model until satisfactory accuracy is achieved. Finally, the instantaneous response surrogate model is used to compute the time-dependent reliability via Monte Carlo simulation. Four case studies are utilized to demonstrate the effectiveness of the ^-IRS method for time-dependent reliability analysis.

关键词： time-dependent reliability Stochastic process Instantaneous response surface method i-IRS Expansion optimal linear estimation method Kriging surrogate model

Nonlinear time-dependent simulation of helix traveling wave tubes

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Chinese Physics B 2011年第7期20卷 483-489页

作者：彭维峰杨中海胡玉禄李建清陆麒如李斌 Vacuum Electronics National Laboratory University of Electronic Science and Technology of China

A one-dimensional nonlinear time-dependent theory for helix traveling wave tubes is studied. A generalized electromagnetic field is applied to the expression of the radio frequency field. To simulate the variations of the high frequency structure, such as the pitch taper and the effect of harmonics, the spatial average over a wavelength is substituted by a time average over a wave period in the equation of the radio frequency field. Under this assumption, the space charge field of the electron beam can be treated by a space charge wave model along with the space charge coefficient. The effects of the radio frequency and the space charge fields on the electrons are presented by the equations of the electron energy and the electron phase. The time-dependent simulation is compared with the frequency-domain simulation for a helix TWT, which validates the availability of this theory.

关键词： helix traveling wave tubes time-dependent harmonics helix pitch taper

Establishing time-dependent model of deformation modulus caused by bedrock excavation rebound by inverse analysis method

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Science China(Technological Sciences) 2008年第S2期51卷 1-7页

作者： WU ZhongRu1,2,GU YanChang1,3,GU ChongShi1,2,GUO HaiQing1 & SU HuaiZhi1,2 1 Hohai University,Nanjing 210098,China 2 National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety,Nanjing 210098,China 3 Nanjing Hydraulic Research Institute,Nanjing 210029,China Hohai University Nanjing China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Nanjing China Nanjing Hydraulic Research Institute Nanjing China

Rock rebound relaxation deformation,or even rock burst,caused by the excavation of dam base and abutment or high rock slope affects their stability and results in the fall of mechanical properties of the *** an inverse analysis method was proposed in this paper to establish the time-dependent model of deformation modulus caused by excavation *** basic principle is based on the combination of observed data of the excavation rebound deformation of dam abutment or rock slope,and the calculated rebound deformation by FEM under ground stress at the corresponding time in the excavation *** norm of the residuals of observed data and calculated data are taken as the objective ***,the time-dependent model of bedrock deformation modulus can be *** method displays its significance in the design of excavation,construction and operation management of dam base and high slope.

关键词： dam base rebound deformation modulus inverse analysis method time-dependent model Xiaowan Hydropower Station

An extended time-dependent numerical model of the mild-slope equation with weakly nonlinear amplitude dispersion

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Acta Oceanologica Sinica 2010年第2期29卷 5-13页

作者： ZHAO Hongjun SONG Zhiyao XU Fumin LI Ruijie Key Laboratory of Coastal Disasters and Defence Ministry of Education Hohai University Nanjing 210098 China Ocean College Hohai University Nanjing 210098 China Key Laboratory of Virtual Geographic Environment Ministry of Education Nanjing Normal University Nanjing 210097 China

In the present paper, by introducing the effective wave elevation, we transform the extended elliptic mild-slope equation with bottom friction, wave breaking and steep or rapidly varying bottom topography to the simplest time-dependent hyperbolic equation. Based on this equation and the empirical nonlinear amplitude dispersion relation proposed by Li et al. （2003）, the numerical scheme is established. Error analysis by Taylor expansion method shows that the numerical stability of the present model succeeds the merits in Song et al. （2007）＇s model because of the introduced dissipation terms. For the purpose of verifying its performance on wave nonlinearity, rapidly varying topography and wave breaking, the present model is applied to study：（1） wave refraction and diffraction over a submerged elliptic shoal on a slope （Berkhoff et al., 1982）; （2） Bragg reflection of monochromatic waves from the sinusoidal ripples （Davies and Heathershaw, 1985）; （3） wave transformation near a shore attached breakwater （Watanabe and Maruyama, 1986）. Comparisons of the numerical solutions with the experimental or theoretical ones or with those of other models （REF/DIF model and FUNWAVE model） show good results, which indicate that the present model is capable of giving favorably predictions of wave refraction, diffraction, reflection, shoaling, bottom friction, breaking energy dissipation and weak nonlinearity in the near shore zone.

关键词： time-dependent mild-slope equation varying topography bottom friction nonlinear amplitude dispersion steep or rapidly wave breaking