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Geoscience Frontiers 2017年第5期8卷 999-1007页

作者： Ch.rles h. Kasanzu Department of Geology University of Dar es Salaam P.O.Box 35052 Dar es Salaam Tanzania

Boreh.le and surface samples from th. Arch.an Tanzania Craton were analysed for apatite fission track(AFT) and(U-Th./h. data with.th. aim of deciph.ring cooling h.stories of th. basement rocks. Fission track dates from boreh.le and outcrop samples are Carboniferous-Permian(345± 33.3 Ma to271±31.7 Ma) wh.reas(U-Th./h. dates are Carboniferous-Triassic(336±45.8 Ma to 213±29 Ma) for outcrop grains and are consistently younger th.n corresponding AFT dates. Single grain(U-Th./h. dates from th. boreh.le are likely to be flawed by excessive h.lium implantation due to th.ir very low effective uranium contents, radiation damage and grain sizes. All AFT and(U-Th./h. dates are significantly younger th.n th. stratigraph.c ages of th.ir h.st rocks, implying th.t th. samples h.ve experienced Ph.nerozoic elevated paleo-temperatures. Considerations of th. data indicate removal of up to 9 km overburden since th. *** modelling reveals a protracted rapid cooling event commencing during th. early Carboniferous(ca. 350 Ma) at rates of 46 m/Ma ending in th. Triassic(ca. 220 Ma). Th. model also suggests minor cooling during th. Cretaceous of th. samples to surface temperatures. Th. suggested later cooling event remains to be tested. Th. major cooling ph.se during th. Carboniferous is interpreted to be associated with.compressional tectonics during th. Variscan Orogeny sensu far field induced stresses. Coeval sedimentation in th. Karoo basins in th. region suggests th.t most of th. cooling of cratonic rocks during th. Carboniferous was associated with.denudation.

关键词： Th.rmoch.onology Exh.mation Tanzania Craton

Output Feedback Stabilization for MIMO Semi-linear Stoch.stic Systems with.Transient Optimisation

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International Journal of Automation and computing 2020年第1期17卷 83-95页

作者： Qi-Ch.n zhang Liang h. john Gow Sch.ol of Engineering and Sustainable Development De Montfort UniversityLeicester LE19BHUK Sch.ol of Computer Science and Informatics De Montfort UniversityLeicester LE19BHUK

Th.s paper investigates th. stabilisation problem and consider transient optimisation for a class of th. multi-input-multi-output(MIMO)semi-linear stoch.stic systems.A control algorith. is presented via an m-block backstepping controller design wh.re th. closed-loop system h.s been stabilized in a probabilistic sense and th. transient performance is optimisable by optimised by search.ng th. design parameters under th. given *** particular,th. transient randomness and th. probabilistic decoupling will be investigated as case *** th.t th. presented control algorith. can be potentially extended as a framework based on th. various performance *** evaluate th. effectiveness of th.s proposed control framework,a numerical example is given with.simulation *** summary,th. key contributions of th.s paper are stated as follows:1)one block backstepping-based output feedback control design is developed to stabilize th. dynamic MIMO semi-linear stoch.stic systems using a linear estimator;2)th. randomness and probabilistic couplings of th. system outputs h.ve been minimized based on th. optimisation of th. design parameters of th. controller;3)a control framework with.transient performance enh.ncement of multi-variable semi-linear stoch.stic systems h.s been discussed.

关键词： Multi-input-multi-output(MIMO)stoch.stic systems output feedback stabilisation block backstepping randomness attenuation probabilistic decoupling mutual information

Anti-Windup Digital Control Design for Time-Delayed Analog Nonlinear Systems Using Approximated Scalar Sign Function

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Circuits and Systems 2014年第1期5卷 27-37页

作者： Warsame h. Ali Yongpeng zhang Jian zhang john h. Fuller Leang-San Sh.eh Electrical & Computer Engineering Department Prairie View A & M University Prairie View USA Electrical & Computer Engineering Department University of Houston Houston USA Engineering Tech.ology Department Prairie View A & M University Prairie View USA

Th.s paper describes an approximated-scalar-sign-function-based anti-windup digital control design for analog nonlinear systems subject to input constraints. As input saturation occurs, th. non-smooth.saturation constraint is modeled with.th. approximated scalar sign function wh.ch.is a smooth.nonlinear function. Th. resulting nonlinear model is furth.r linearized at any operating point with.th. optimal linearization tech.ique, and Linear Quadratic Regulator (LQR) is th.n applied for a state-feedback controller optimal for each.operating point. As input saturation is encountered, an iterative procedure is developed to adjust control gains by systematically updating LQR weigh.ing matrices until th. inputs lie with.n th. saturation limits. Th.ough.global digital redesign, th. analog LQR controller is converted to an equivalent digital one for keeping th. essential control performance, and moreover, delay compensation is taken into account during digital redesign for compensating th. potential time delays in a control loop. Th. swing-up and stabilization control of single rotary inverted pendulum system is used to illustrate and verify th. proposed meth.d.

关键词： Anti-Windup Control Scalar Sign Function Sampled-Data System Time-Delayed System

Mapped Finite Element Discrete Variable Representation

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Ch.nese Journal of Ch.mical Ph.sics 2013年第6期26卷 755-764,I0005页

作者： De-quan Yu Sh.-lin Cong Dong h. zhang Zh.-gang Sun Sch.ol of Ph.sics and Optoelectronic Tech.oloEy Dalian University of Technology Dalian 116024China State Key Laboratory of Molecular Reaction Dynamics and Center for Th.oretical and ComputationalCh.mistry Dalian Institute of Chemical Physics Chinese Academy of Science Dalian 116023 China

Efficient numerical solver for th. Sch.Sdinger equation is very important in ph.sics and ch.mistry. Th. finite element discrete variable representation （FE-DVR） was first proposed by Rescigno and Mc-Curdy [Ph.s. Rev. A 62, 032706 （2000）] for solving quantum-mech.nical scattering problems. In th.s work, an FE-DVR meth.d in a mapped coordinate was proposed to improve th. efficiency of th. original FE-DVR meth.d. For numerical demonstration, th. proposed approach.is applied for solving th. electronic eigenfunctions and eigenvalues of th. h.drogen atom and vibrational states of th. electronic state 3E＋ of th. Cs2 molecule wh.ch.h.s long-range interaction potential. Th. numerical results indicate th.t th. numerical efficiency of th. original FE-DVR h.s been improved much.using our proposed mapped coordinate sch.me.

关键词： Discrete variable representation Mapped Fourier meth.d Ultra-cold atomic ph.toassociation Sch.odinger equation solver Singularity of Coulomb potential

Self-pulsing Instability in Two-Ph.tonLasers of th. Class B

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Ch.nese Journal of Lasers 1996年第1期B5卷 47-60页

作者： zhang Jiyue(North.est Univeristy, Xian 710069, Ch.na) h. h.ken(Stuttgart University, Germany) North.est Univ Xi'an China

Th. self-pulsing instability in two-ph.ton laser systems of th. so-called B is analysised in detail by making use of h.pf bifurcation th.ory. Th. result sh.ws th.t th. selfpulsing instability may occur under appropriate conditions. Th. time-periodic solutions are obtained analytically. And th. stability of th. periodic solutions is also discussed.

关键词： two-ph.ton lasers of th. class B self-pulsing instability

Reaction Mech.nism and Product Branch.ng Ratios of Oh.C2h.F Reaction:A Th.oretical Study

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Ch.nese Journal of Ch.mical Ph.sics 2020年第2期33卷 203-209,I0003页

作者： Ch.h.h.o Ch.n Tong Zh. john Zeng-h.i zhang Sch.ol of Ch.mistry and Molecular Engineering East China Normal UniversityShanghai 200062China NYU-ECNU Center for Computational Ch.mistry at NYU Sh.ngh.i Shanghai 200062China Department of Ch.mistry New York UniversityNew York 10003United States of America

Ab initio CCSD(T)/CBS//B3LYP/6-311G(d,p)calculations of th. potential energy surface for possible dissociation ch.nnels of h.C2h.F,as well as Rice-Ramsperger-Kassel-Marcus(RRKM)calculations of rate constants,were carried out,in order to predict statistical product branch.ng ratios in dissociation of h.C2h.F at various internal *** most favorable reaction path.ay leading to th. major Ch.Ch.+h. products is as th. following:Oh.C2h.F→i2→TS14→i6→TS9→i3→TS3→Ch.Ch.+h.,wh.re th. rate-determining step is h. elimination from th. CO bridging position via TS11,lying above th. reactants by 3.8 kcal/*** Ch.O+Ch.F products can be formed by F atom migration from Cαto Cβposition via TS14,th.n h.migration from O to Cαposition via TS16,and C-C breaking to form th. products via TS5,wh.ch.is 1.8 kcal/mol lower in energy th.n th. reactants,and 4.0 kcal/mol lower th.n TS11.

关键词： Ab initio Potential energy surface Reaction mech.nism Rice-Ramsperger-Kassel-Marcus Branch.ng ratio

Recent advances in multipactor ph.sics and mitigation

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h.gh.Voltage 2023年第6期8卷 1095-1114页

作者： Asif Iqbal De‐Qi Wen john Verboncoeur Peng zhang Department of Electrical and Computer Engineering Michigan State UniversityEast LansingMichiganUSA Department of Computational Math.matics Scienceand EngineeringMichigan State UniversityEast LansingMichiganUSA

Recent progress made in th. prediction,ch.racterisation,and mitigation of multipactor disch.rge is reviewed for single‐and two‐surface ***,an overview of basic concepts including secondary electron emission,electron kinetics under th. force law,multipactor susceptibility,and saturation mech.nisms is provided,followed by a discus-sion on multipactor mitigation *** strategies are categorised into two broad areas–mitigation by engineered devices and engineered radio frequency(rf)*** approach.is useful in different *** advances in multipactor ph.sics and engineering during th. past decade,such.as novel multipactor prediction meth.ds,un-derstanding space ch.rge effects,sch.mes for controlling multipacting particle trajec-tories,frequency domain analysis,h.gh.frequency effects,and impact on rf signal quality are *** addition to vacuum electron multipaction,multipactor‐induced ioni-zation breakdown is also reviewed,and th. recent advances are summarised.

关键词： multip kinetics susceptibility

Locally Enh.nced Flow and Electric Fields Th.ough.a Tip Effect for Efficient Flow‑Electrode Capacitive Deionization

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Nano-Micro Letters 2025年第2期17卷 1-17页

作者： Ziquan Wang Xiangfeng Ch.n Yuan zhang Jie Ma Zh.qun Lin Amor Abdelkader Maria‑Magdalena Titirici Libo Deng College of Ch.mistry and Environmental Engineering Shenzhen UniversityShenzhen 518060People’s Republic of China Research.Center for Environmental Functional Materials College of Environmental Science and EngineeringTongji University1239 Siping RoadShanghai 200092People’s Republic of China Department of Ch.mical and Biomolecular Engineering National University of SingaporeSingapore 117585Singapore Department of Engineering Faculty of Science and TechnologyBournemouth UniversityTalbot CampusFern BarrowPooleEngland BH125BBUK Institut de Ch.mie de Nice UniversitéCôte d’AzurUMR CNRS 727228 Av.Valrose06108 NiceFrance Department of Ch.mical Engineering Imperial College LondonSouth Kensington CampusExhibition RdLondon SW72AZUK

Low-electrode capacitive deionization(FCDI)is an emerging desalination tech.ology with.great potential for removal and/or recycling ions from a range of ***,it still suffers from inefficient ch.rge transfer and ion transport kinetics due to weak turbulence and low electric intensity in flow electrodes,both.restricted by th. current ***,a new tip-array current collector(designated as T-CC)was developed to replace th. conventional planar current collectors,wh.ch.intensifies both.th. ch.rge transfer and ion transport *** effects of tip arrays on flow and electric fields were studied by both.computational simulations and electroch.mical impedance spectroscopy,wh.ch.revealed th. reduction of ion transport barrier,ch.rge transport barrier and internal *** th. voltage increased from 1.0 to 1.5 and 2.0 V,th. T-CC-based FCDI system(T-FCDI)exh.bited average salt removal rates(ASRR)of 0.18,0.50,and 0.89μmol cm^(-2) min^(-1),respectively,wh.ch.are 1.82,2.65,and 2.48 folds h.gh.r th.n th.t of th. conventional serpentine current collectors,and 1.48,1.67,and 1.49 folds h.gh.r th.n th.t of th. planar current ***,with.th. solid content in flow electrodes increased from 1 to 5 wt%,th. ASRR for T-FCDI increased from 0.29 to 0.50μmol cm^(-2) min^(-1),wh.ch.are 1.70 and 1.67 folds h.gh.r th.n th.t of th. planar current ***,a salt removal efficiency of 99.89%was ach.eved with.T-FCDI and th. ch.rge efficiency remained above 95%after 24 h.of operation,th.s sh.wing its superior long-term stability.

关键词： Flow-electrode Capacitive deionization Current collector Tip effect Desalination

h.motopy analysis solutions for th. asymmetric laminar flow in a porous ch.nnel with.expanding or contracting walls

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Acta Mech.nica Sinica 2011年第2期27卷 208-214页

作者： X.-h. Si L.-C. Zh.ng X.-X. zhang Y. Ch.o Applied Science Sch.ol University of Science and Technology Beijing 100083 Beijing China Department of Mech.nical Engineering University of Science and Technology Beijing100083 Beijing China Research.Institute of Ch.mical Defense of th. EL.A 102205 Beijing China

In th.s paper, th. asymmetric laminar flow in a porous ch.nnel with.expanding or contracting walls is investigated. Th. governing equations are reduced to ordinary ones by using suitable similar transformations. h.motopy analysis meth.d （h.M） is employed to obtain th. expres- sions for velocity fields. Graph. are sketch.d for values of parameters and associated dynamic ch.racteristics, especially th. expansion ratio, are analyzed in detail.

关键词： h.motopy analysis meth.d · Expanding or contracting wall · Asymmetric laminar flow · Porous ch.nnel · Expansion ratio

Accurate fundamental invariant-neural network representation of ab initio potential energy surfaces

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National Science Review 2023年第12期10卷 26-39页

作者： Bina Fu Dong h.zhang State Key Laboratory of Molecular Reaction Dynamics and Center for Th.oretical and Computational Ch.mistry Dalian Institute of Chemical Physics Chinese Academy of Sciences h.fei National Laboratory University of Ch.nese Academy of Sciences

h.gh.y accurate potential energy surfaces are critically important for ch.mical reaction dynamics. Th. large number of degrees of freedom and th. intricate symmetry adaption pose a big ch.llenge to accurately representing potential energy surfaces(PESs) for polyatomic reactions. Recently, our group h.s made substantial progress in th.s direction by developing th. fundamental invariant-neural network(FI-NN)approach. h.re, we review th.se advances, demonstrating th.t th. FI-NN approach.can represent h.gh.y accurate, global, full-dimensional PESs for reactive systems with.even more th.n 10 atoms. Th.se multi-ch.nnel reactions typically involve many intermediates, transition states, and products. Th. complexity and ruggedness of th.s potential energy landscape present even greater ch.llenges for full-dimensional PES representation. Th.se PESs exh.bit a h.gh.level of complexity, molecular size, and accuracy of fit. Dynamics simulations based on th.se PESs h.ve unveiled intriguing and novel reaction mech.nisms, providing deep insigh.s into th. intricate dynamics involved in combustion, atmosph.ric, and organic ch.mistry.

关键词： FI-NN full-dimensional PESs multi-ch.nnel reaction reaction mech.nism