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Multiphysics processes in the interfacial transition zone of fiber-reinforced cementitious composites under induced curing pressure and implications for mine backfill materials: A critical review

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International Journal of Minerals,Metallurgy and Materials 2023年第8期30卷 1474-1489页

作者： Brett Holmberg Liang cui Department of Civil Engineering Lakehead UniversityThunder BayON P7B 5E1Canada

The mesoscale fiber-matrix interfacial transition zone(FM-ITZ) under induced curing pressure plays a key role in the effectiveness of fiber reinforcement and the engineering application of fiber-reinforced cementitious composites(FRCCs). This critical review establishes the link among induced curing pressure(i.e., external loading condition), multiphysics processes(i.e., internal governing mechanism), and interface behavior(i.e., material behavior) for FRCC materials through analysis of the state-of-the-art research findings on the FM-ITZ of FRCC materials. The following results are obtained. For the mechanical process, the induced curing pressure changes the stress state and enhances multicracking behavior, which can strengthen the FM-ITZ. For the hydraulic process, the strengthened seepage of the FM-ITZ under induced curing pressure weakens the effective stress and exaggerates the deficiency in water retention capacity between the bulk matrix and the FMITZ. For the thermal process, the induced curing pressure causes a steep temperature gradient in the FM-ITZ and thus influences the temperature evolution and thermally-induced microcracks in the FM-ITZ. For the chemical process, the induced curing pressure enhances hydration kinetics and results in the formation of additional hydration products in the FM-ITZ. Moreover, recommendations are proposed on the basis of findings from this review to facilitate the implementation of fiber reinforcement in cemented paste backfill technology.

关键词： cemented paste backfill cementitious composites interfacial transition zone fiber reinforcement multiphysics induced curing pressure

Tightness of certain monomials

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Science China Mathematics 2015年第6期58卷 1297-1304页

作者： cui WeiDeng Mathematical Sciences Center Tsinghua University

For a quantized enveloping algebra of finite type, one can associate a natural monomial to a dominant weight. We show that these monomials for types A5 and D4 are semitight(i.e., a Z-linear combination of elements in ... 详细信息

关键词： algebra canonical Cartan tight proof bilinear associate irreducible concerned integer

Adjoint-free calculation method for conditional nonlinear optimal perturbations

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Science China Mathematics 2015年第7期58卷 1567-1576页

作者： cui Ming College of Applied Sciences Beijing University of Technology State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences

Adjoint-free calculation method is proposed to compute conditional nonlinear optimal perturbations(CNOp) combined with initial perturbations and model parameter perturbations. The new approach avoids the use of adjoint technique in the optimization process. CNOps respectively generated by ensemble-based and adjoint-based methods are compared based on a simple theoretical model.

关键词： conditional nonlinear optimal perturbation (CNOp) ensemble-based method adjoint method

On Commuting Tonelli Hamiltonians: Time-periodic Case

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Acta Mathematica Sinica,English Series 2014年第10期30卷 1698-1718页

作者： xiaojun cui Department of Mathematics Nanjing University

We show that the Aubry sets, the Mane sets and the barrier functions are the same for two commuting time-periodic Tonelli Hamiltonians.

关键词： Aubry set Mane set barrier function viscosity solution

TeV gamma-ray astronomy

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Research in Astronomy and Astrophysics 2009年第8期9卷 841-860页

作者： Wei cui Department of physics Purdue University 525 Northwestern Avenue West Lafayette IN 47907 USA

The field of ground-based gamma-ray astronomy has enjoyed rapid growth in recent years. As an increasing number of sources are detected at TeV energies, the field has matured and become a viable branch of modern astronomy. Lying at the uppermost end of the electromagnetic rainbow, TeV photons are always preciously few in number but carry essential information about the particle acceleration and radiative processes involved in extreme astronomical settings. Together with observations at longer wavelengths, TeV gamma-ray observations have drastically improved our view of the universe. In this re- view, we briefly describe recent progress in the field. We will conclude by providing a personal perspective on the future of the field, in particular, on the significant roles that China could play in advancing this young but exciting field.

关键词： gamma-rays observations

Near-field wideband channel estimation for extremely large-scale MIMO

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Science China(Information Sciences) 2023年第7期66卷 283-296页

作者： Mingyao cui Linglong DAI Department of Electronic Engineering Tsinghua University Beijing National Research Center for Information Science and Technology(BNRist)

Extremely large-scale multiple-input-multiple-output(xL-MIMO) at millimeter-wave(mm Wave)and terahertz(THz) bands plays an important role in supporting extreme high beamforming gain as well as ultra-wideband spectrum resources. Unfortunately, accurate wideband xL-MIMO channel estimation suffers from a new challenge called the near-field beam split effect. prior studies either neglect the accurate nearfield channel model or fail to exploit the beam split effect, resulting in poor channel estimation accuracy for wideband xL-MIMO. To tackle this problem, this paper proposes a bilinear pattern detection(BpD)-based approach to accurately recover the wideband xL-MIMO channel. Specifically, by analyzing the characteristics of near-field wideband channels, we first reveal the bilinear pattern of the near-field beam split effect, which implies that the sparse support set of near-field channels in both the angle and the distance domains can be regarded as a linear function against frequency. Then, inspired by the classical simultaneously orthogonal matching pursuit technique, we use the bilinear pattern to estimate the angle-of-arrival(Ao A) and distance parameters of each near-field path component at all frequencies. In this way, the entire wideband xL-MIMO channel can be recovered by compressed sensing algorithms. Moreover, we provide the computational complexity of the proposed algorithm compared with existing algorithms. Finally, simulation results demonstrate that our scheme can achieve the accurate estimation of the near-field wideband xL-MIMO channel in the presence of near-field beam split effect.

关键词： xL-MIMO wideband near-field beam split channel estimation

Number of Solitons Emerged in the Initial profile of Shallow Water Using Convolutional Neural Networks

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Journal of Systems Science & Complexity 2024年第2期37卷 463-479页

作者： WANG Zhen cui Shikun School of Mathematical Sciences Dalian University of TechnologyDalian 116024China School of Mathematical Sciences Beihang UniversityBeijing 100191China

The soliton resolution conjecture proposes that the initial value problem can evolve into a dispersion part and a soliton ***,the problem of determining the number of solitons that form in a given initial profile remains unsolved,except for a few specific *** this paper,the authors use the deep learning method to predict the number of solitons in a given initial value of the Korteweg-de Vries(KdV)*** leveraging the analytical relationship between Asech^(2)(x)initial values and the number of solitons,the authors train a Convolutional Neural Network(CNN)that can accurately identify the soliton count from spatio-temporal *** trained neural network is capable of predicting the number of solitons with other given initial values without any additional *** extensive calculations,the authors demonstrate the effectiveness and high performance of the proposed method.

关键词： Convolutional neural network deep learning method KdV equation soliton

Geometry independent C^(*)-T_(z) dominance of three-dimensional quasistatic growing crack-tip fields in creeping solids

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Science China(physics,Mechanics & Astronomy) 2022年第1期65卷 22-32页

作者： pengFei cui WanLin Guo State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In creeping solids,plane stress and plane strain solutions for asymptotic singular crack-tip fields have been first put forward by Riedel and Rice with C^(*)as the dominating parameter and developed by xiang and Guo into three-dimensional solution(3D)for stationary cracks under the domination of C^(*)with the constraint factor ***,how to characterize the 3D crack-tip fields under creep damage-induced quasistatic growing conditions remains *** this study,we reveal that,for 3D quasistatic growing cracks,the leading singular solution can effectively characterize the crack-tip stress distributions with relative errors less than 10.8%for relative creep time up to 0.8 in various specimens with finite *** a given relative time,Tz distributions can be unified by the equivalent thickness concept,*** results show that C^(*)-T_(z) can effectively quantify both the load and constraint effects on the crack-tip *** geometry independent dominance can considerably simplify the treatments of load and constraint effects,thereby promoting the application of fracture mechanics in high-temperature damage tolerance designs.

关键词： quasistatic growing crack-tip fields C^(*)-T_(z)solution geometry independence constraints creep damage

Estimation in partial linear EV models with replicated observations

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Science China Mathematics 2004年第1期47卷 144-159页

作者： cui Hengjian Department of Mathematics Statistical Data Analysis Laboratory Beijing Normal University Beijing 100875China

The aim of this work is to construct the parameter estimators in the partial linear errors-in-variables (EV) models and explore their asymptotic properties. Unlike other related References, the assumption of known error covariance matrix is removed when the sample can be repeatedly drawn at each designed point from the model. The estimators of interested regression parameters, and the model error variance, as well as the nonparametric function, are constructed. Under some regular conditions, all of the estimators prove strongly consistent. Meanwhile, the asymptotic normality for the estimator of regression parameter is also presented. A simulation study is reported to illustrate our asymptotic results.

关键词： partial linear EV model, strong consistency, replicated observations.