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unified solutions for stresses and displacements around circular tunnels using the unified Strength Theory

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Science China(Technological Sciences) 2010年第6期53卷 1694-1699页

作者： ZHANG ChangGuang1,WANG JiangFeng2 & ZHAO JunHai3 1 Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China 2 North China Institute of Water Conservancy and Hydroelectric Power,Zhengzhou 450011,China 3 School of Civil Engineering,Chang’an University,Xi’an 710061,China 1. Department of Geotechnical Engineering Tongji University Shanghai 200092 China2. North China Institute of Water Conservancy and Hydroelectric Power Zhengzhou 450011 China3. School of Civil Engineering Chang’an University Xi’an 710061 China

The unified solutions are presented for stresses and displacements around a circular tunnel subjected to a hydrostatic stress *** rock mass is assumed to be elastic-brittle-plastic and governed by the unified Strength *** displacements are obtained accounting for three different definitions for elastic strains and different Young's modulus in the plastic *** unified solutions obtained in this paper are especially versatile in reflecting the intermediate principal stress effect to different extents for different *** conventional solutions,based on the Mohr-Coulomb failure criterion and the Generalized Twin Shear Stress yield criterion,are special cases of the present unified *** new unified solutions can compare with those computed by the latest generalized Hoek-Brown failure *** results obtained demonstrate the importance of the intermediate principal stress influence for the stresses and displacements *** effects of different definitions for elastic strains and different Young's modulus in the plastic zone on the displacements are significant.

关键词： unified Strength Theory intermediate principal stress different definitions for elastic strains different Young’s modulus

unified Description of the EMC Effect and Nuclear Shadowing Effect

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Chinese Physics Letters 1993年第11期10卷 648-651页

作者： LI Guanglie SHEN Jianping YU Mingjian Institute of High Energy Physics Academia Sinicat Bering 100039

The parton evolution model is improved by using the modified Alteralli-Parisi equation which can describe the nuclear shadowing and antishadowing effects in the small x *** the theoretical framework of the improved parton evolution modelt the unified description of the European Muon Collaboration(EMC)effect,and nuclear shadowing and antishad owing effects is given without introducing the nuclear shadowing factor.

关键词： unified introducing equation

Monogamy and polygamy relations of multiqubit entanglement based on unified entropy

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Chinese Physics B 2020年第2期29卷 129-136页

作者： Zhi-Xiang Jin Cong-Feng Qiao School of Physics University of Chinese Academy of SciencesBeijing 100049China CAS Center for Excellence in Particle Physics Beijing 100049China

Monogamy relation is one of the essential properties of quantum entanglement,which characterizes the distribution of entanglement in a multipartite *** virtual of the unified-(q,s) entropy,we obtain some novel monogamy and polygamy inequalities in general class of entanglement *** the multiqubit system,a class of tighter monogamy relations are established in term of the a-th power of unified-(q,s) entanglement for a> *** also obtain a class of tighter polygamy relations in the β-th(0≤β≤1) power of unified-(q,s) entanglement of *** these results to specific quantum correlations,e.g.,entanglement of formation,Renyi-q entanglement of assistance,and Tsallisq entanglement of assistance,we obtain the corresponding monogamy and polygamy *** examples are presented for ***,the complementary monogamy and polygamy relations are investigated for theα-th(0≤α≤1) and β-th(β≥1) powers of unified entropy,respectively,and the corresponding monogamy and polygamy inequalities are obtained.

关键词： quantum monogamy quantum polygamy unified entropy

Mitigation of power system forced oscillations based on unified power flow controller

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Journal of Modern Power Systems and Clean Energy 2019年第1期7卷 99-112页

作者： Ping JIANG Zikai FAN Shuang FENG Xi WU Hui CAI Zhenjian XIE School of Electrical Engineering Southeast University State Grid Jiangsu Economic Research Institute

Forced oscillations(FOs), or low-frequency oscillations(LFOs) caused by periodic, continuous, small power disturbances, threaten the security and stability of power *** AC transmission system(FACTS)devices can effectively mitigate LFOs via stability *** propose a novel method that mitigates FOs by shifting the resonant *** on the features of the linearized swing equation of a generator, a resonant frequency shift can be achieved by controlling the synchronous torque coefficient using a unified power flow controller(UPFC).Because of the resonance mechanism, the steady-state response of an FO can be effectively mitigated when the resonant frequency changes from the original one, which was close to the disturbance *** principle is that a change in resonant frequency affects the resonance *** are conducted in a single-machine infinite-bus(SMIB) system, and the simulation results verify that the method is straightforward to implement and can significantly mitigate *** controller robustness when the resonant frequency is not accurately estimated is also analyzed in the simulations.

关键词： Forced oscillations Flexible AC transmission systems unified power flow controller Stability control

A unified gas-kinetic scheme for multiscale and multicomponent flow transport

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Applied Mathematics and Mechanics(English Edition) 2019年第3期40卷 355-372页

作者： Tianbai XIAO Kun XU Qingdong CAI Department of Mechanics and Engineering Science College of EngineeringPeking University Department of Mathematics Hong Kong University of Science and Technology Department of Mechanical and Aerospace Engineering Hong Kong University of Science and Technology Shenzhen Research Institute Hong Kong University of Science and Technology

Compressible flows exhibit a diverse set of behaviors, where individual particle transports and their collective dynamics play different roles at different scales. At the same time, the atmosphere is composed of different components that require additional degrees of freedom for representation in computational fluid dynamics. It is challenging to construct an accurate and efficient numerical algorithm to faithfully represent multiscale flow physics across different regimes. In this paper, a unified gas-kinetic scheme(UGKS) is developed to study non-equilibrium multicomponent gaseous flows. Based on the Boltzmann kinetic equation, an analytical space-time evolving solution is used to construct the discretized equations of gas dynamics directly according to cell size and scales of time steps, i.e., the so-called direct modeling method. With the variation in the ratio of the numerical time step to the local particle collision time(or the cell size to the local particle mean free path), the UGKS automatically recovers all scale-dependent flows over the given domain and provides a continuous spectrum of the gas dynamics. The performance of the proposed unified scheme is fully validated through numerical *** UGKS can be a valuable tool to study multiscale and multicomponent flow physics.

关键词： unified gas-kinetic scheme(UGKS) multiscale modeling multicomponent flow

unified representation of gravitation field in consideration of effect of ellipsoid flattening

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Chinese Science Bulletin 1997年第19期42卷 1631-1636页

作者： ZHU ZhuowenLaboratory for Modern Geodynamics, Wuhan Technical University of Surveying and Mapping, Wuhan 430079, China Laboratory for Modern Geodynamics Wuhan Technical University of Surveying and Mapping Wuhan China

THE theory of unified representation of gravitation field proposed by the author is modelledupon spherical approximation for disturbing potential. It is a common knowledge that sphericalapproximation should lead to a result involving an innate error. This kind of error is tolerableonly for general application, an ellipsoidal correction has to be taken into account in case of de-siring for a result with higher accuracy. The purpose of this note is to try to make an

关键词： unified representation of gravitation field interior Dirichlet’ s problem of biharmonic equation for ellipsoidal domain radial shrinking mapping approximation problem anomalous density.

A novel unified model predicting flow stress and grain size evolutions during hot working of non-uniform as-cast 42CrMo billets

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Chinese Journal of Aeronautics 2019年第2期32卷 531-545页

作者： Lianggang GUO Fengqi WANG Pengliang ZHEN Xuechao LI Mei ZHAN School of Materials Science and Engineering Northwestern Polytechnical University

The cast preformed forming process(CPFP) is increasingly considered and applied in the metal forming industries due to its short process, low cost, and environmental friendliness, especially in the aerospace field. However, how to establish a unified model of a non-uniform as-cast billet depicting the flow stress and microstructure evolution behaviors during hot working is the key to microstructure prediction and parameter optimization of the CPFP. In this work, hot compression tests are performed using a non-uniform as-cast 42 CrMo billet at 1123–1423 K and 0.01–1sà1. The effect laws of the non-uniform state of the as-cast billet with different initial grain sizes on the flow stress and microstructure are revealed deeply. Based on experimental results, a unified model of flow stress and grain size evolutions is developed by the internal variable modeling method. Verified results show that the model can well describe the responses of the flow stress and microstructure to deformation conditions and initial grain sizes. To further evaluate its reliability, the unified model is applied to FE simulation of the cast preformed ring rolling *** predictions of the rolling force and grain size indicate that it could well describe the flow stress and microstructure evolutions during the process.

关键词： Cast preformed forming process Flow stress Grain size Non-uniform as-cast 42CrMo billet Ring rolling unified model

MgNet: A unified framework of multigrid and convolutional neural network

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Science China Mathematics 2019年第7期62卷 1331-1354页

作者： Juncai He Jinchao Xu School of Mathematical Sciences Peking University Beijing 100871 China Department of Mathematics The Pennsylvania State University University Park PA 16802 USA

We develop a unified model, known as MgNet, that simultaneously recovers some convolutional neural networks (CNN) for image classification and multigrid (MG) methods for solving discretized partial differential equations (PDEs). This model is based on close connections that we have observed and uncovered between the CNN and MG methodologies. For example, pooling operation and feature extraction in CNN correspond directly to restriction operation and iterative smoothers in MG, respectively. As the solution space is often the dual of the data space in PDEs, the analogous concept of feature space and data space (which are dual to each other) is introduced in CNN. With such connections and new concept in the unified model, the function of various convolution operations and pooling used in CNN can be better understood. As a result, modified CNN models (with fewer weights and hyperparameters) are developed that exhibit competitive and sometimes better performance in comparison with existing CNN models when applied to both CIFAR-10 and CIFAR-100 data sets.

关键词： convolutional neural network multigrid unified framework net work architecture

A unified study of continuous and discontinuous Galerkin methods

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Science China Mathematics 2019年第1期62卷 1-32页

作者： Qingguo Hong Fei Wang Shuonan Wu Jinchao Xu Department of Mathematics Pennsylvania State University University Park School of Mathematics and Statistics Xi'an Jiaotong University

A unified study is presented in this paper for the design and analysis of different finite element methods(FEMs), including conforming and nonconforming FEMs, mixed FEMs, hybrid FEMs, discontinuous Galerkin(DG) methods, hybrid discontinuous Galerkin(HDG) methods and weak Galerkin(WG) *** HDG and WG are shown to admit inf-sup conditions that hold uniformly with respect to both mesh and penalization parameters. In addition, by taking the limit of the stabilization parameters, a WG method is shown to converge to a mixed method whereas an HDG method is shown to converge to a primal method. Furthermore,a special class of DG methods, known as the mixed DG methods, is presented to fill a gap revealed in the unified framework.

关键词： finite element methods DG-derivatives unified study