检索结果-南通市图书馆

Macroscopic damping model for structural dynamics with random polycrystalline configurations

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2018年第3期34卷 493-506页

作者： Yantao Yang Junzhi Cui Yifan Yu Meizhen Xiang Academy of Mathematics and Systems Science Chinese Academy of Sciences Laboratory of computational Physics Institute of Applied Physics and Computational Mathematics

In this paper the macroscopic damping model for dynamical behavior of the structures with random polycrystalline configurations at micro-nano scales is established. First, the global motion equation of a crystal is decomposed into a set of motion equations with independent single degree of freedom （SDOF） along normal discrete modes, and then damping behavior is introduced into each SDOF motion. Through the interpolation of discrete modes, the continuous representation of damping effects for the crystal is obtained. Second, from energy conservation law the expression of the damping coefficient is derived, and the approximate formula of damping coefficient is given. Next, the continuous damping coefficient for polycrystalline cluster is expressed, the continuous dynamical equation with damping term is obtained, and then the concrete damping coefficients for a polycrystalline Cu sample are shown. Finally, by using statistical two-scale homogenization method, the macroscopic homogenized dynamical equation containing damping term for the structures with random polycrystalline configurations at micro-nano scales is set up.

关键词： Polycrystalline cluster Dynamical equation Damping coefficient Two-scale homogenization method Atomic-Continuum Coupled Model

Differential Splicing of Skipped Exons Predicts Drug Response in Cancer Cell Lines

在线全文

学校读者我要写书评

暂无评论

Genomics, Proteomics & Bioinformatics 2021年第6期19卷 901-912页

作者： Edward Simpson Steven Chen Jill L.Reiter Yunlong Liu Center for computational Biology and Bioinformatics Indiana University School of MedicineIndianapolisIN 46202USA Department of Biohealth informatics School of Informatics and ComputingIndiana University-Purdue University IndianapolisIndianapolisIN 46202USA Department of Medical and Molecular Genetics Indiana University School of MedicineIndianapolisIN 46202USA

Alternative splicing of pre-mRNA transcripts is an important regulatory mechanism that increases the diversity of gene products in *** studies have linked specific transcript isoforms to altered drug response in cancer;however,few algorithms have incorporated splicing information into drug response *** this study,we evaluated whether basal-level splicing information could be used to predict drug sensitivity by constructing doxorubicin-sensitivity classification models with splicing and expression *** detailed splicing differences between sensitive and resistant cell lines by implementing quasi-binomial generalized linear modeling(QBGLM)and found altered inclusion of 277 skipped *** additionally conducted RNA-binding protein(RBP)binding motif enrichment and differential ex-pression analysis to characterize cis-and trans-acting elements that potentially influence doxorubicin response-mediating splicing *** results showed that a classification model built with skipped exon data exhibited strong predictive *** discovered an association between differentially spliced events and epithelial-mesenchymal transition(EMT)and observed motif enrichment,as well as differential expression of RBFOX and ELAVL RBP family *** work demonstrates the potential of incorporating splicing data into drug response algorithms and the utility of a QBGLM approach for fast,scalable identification of relevant splicing differences between large groups of samples.

关键词： Alternative splicing Transcript isoform Splicing regulation Drug sensitivity Precision medicine

Local Discontinuous Galerkin Method for Parabolic Interface Problems

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2015年第2期31卷 453-466页

作者： Zhi-juan ZHANG Xi-jun YU Department of Mathematics Nanchang University Laboratory of computational Physics Institute of Applied Physics and Computational Mathematics

In this paper, the minimal dissipation local discontinuous Galerkin method is studied to solve the parabolic interface problems in two-dimensional convex polygonal domains. The interface may be arbitrary smooth curves. The proposed method is proved to be L2 stable and the order of error estimates in the given norm is O（h｜logh｜^1/2）. Numerical experiments show the efficiency and accuracy of the method.

关键词： parabolic interface problem minimal dissipation local discontinuous Galerkin method error estimates

Accurate Deep Potential model for the Al-Cu-Mg alloy in the full concentration space

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第5期30卷 12-19页

作者： Wanrun Jiang Yuzhi Zhang Linfeng Zhang Han Wang Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China Beijing Institute of Big Data Research Beijing 100871China Yuanpei College of Peking University Beijing 100871China program in Applied and computational Mathematics Princeton UniversityPrincetonNJ 08544USA Laboratory of computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100088China

Combining first-principles accuracy and empirical-potential efficiency for the description of the potential energy surface(PES)is the philosopher's stone for unraveling the nature of matter via atomistic *** has been particularly challenging for multi-component alloy systems due to the complex and non-linear nature of the associated *** this work,we develop an accurate PES model for the Al-Cu-Mg system by employing deep potential(DP),a neural network based representation of the PES,and DP generator(DP-GEN),a concurrent-learning scheme that generates a compact set of ab initio data for *** resulting DP model gives predictions consistent with first-principles calculations for various binary and ternary systems on their fundamental energetic and mechanical properties,including formation energy,equilibrium volume,equation of state,interstitial energy,vacancy and surface formation energy,as well as elastic *** benchmark shows that the DP model is ready and will be useful for atomistic modeling of the Al-Cu-Mg system within the full range of concentration.

关键词： potential energy surface deep learning Al-Cu-Mg alloy materials simulation

Gravitational effects on global hemodynamics in different postures:A closed-loop multiscale mathematical analysis

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2017年第3期33卷 595-618页

作者： Xiancheng Zhang Shigeho Noda Ryutaro Himeno Hao Liu Graduate School of Engineering Chiba University computational Science Research program RIKEN Shanghai Jiao Tong University and Chiba University International Cooperative Research Center (SJTU-CU ICRC)

We present a novel methodology and strategy to predict pressures and flow rates in the global cardiovascular network in different postures varying from supine to upright. A closed-loop, multiscale mathematical model of the entire cardiovascular system (CVS) is developed through an integration of one-dimensional (1D) modeling of the large systemic arteries and veins, and zero-dimensional (0D) lumped-parameter modeling of the heart, the cardiac-pulmonary circulation, the cardiac and venous valves, as well as the microcirculation. A versatile junction model is proposed and incorporated into the 1D model to cope with splitting and/or merging flows across a multibranched junction, which is validated to be capable of estimating both subcritical and supercritical flows while ensuring the mass conservation and total pressure continuity. To model gravitational effects on global hemodynamics during postural change, a robust venous valve model is further established for the 1D venous flows and distributed throughout the entire venous network with consideration of its anatomically realistic numbers and locations. The present integrated model is proven to enable reasonable prediction of pressure and flow rate waveforms associated with cardiopulmonary circulation, systemic circulation in arteries and veins, as well as microcirculation within normal physiological ranges, particularly in mean venous pressures, which well match the in vivo measurements. Applications of the cardiovascular model at different postures demonstrate that gravity exerts remarkable influence on arterial and venous pressures, venous returns and cardiac outputs whereas venous pressures below the heart level show a specific correlation between central venous and hydrostatic pressures in right atrium and veins.

关键词： Gravitational effects Cardiovascular system (CVS) Postural change Multiscale cardiovascular model Multibranched junction model Venous valve

Computerized cell tracking:Current methods,tools and challenges

在线全文

学校读者我要写书评

暂无评论

Visual informatics 2021年第1期5卷 1-13页

作者： Neda Emami Zahra Sedaei Reza Ferdousi Department of health Information Technology School of Management and Medical InformaticsTabriz University of Medical SciencesTabriz5166/15731Iran Department of health Services Management School of Management and Medical InformaticsTabriz University of Medical SciencesTabriz5166/15731Iran

In developmental biology,knowledge of cell structure and their(morpho)dynamic behavior,leads to a comprehensive understanding of their conducts and the mechanisms in which they *** knowledge is a decisive factor in biological research and also in all drug development steps,medicinal or preventive *** cell analysis is hard,expensive,and *** overcome these difficulties,in recent years,several computational object tracking methods,software system and packages have been developed in cell sciences that bring together different disciplines and branches of *** tracking is the process of locating and monitoring specific object and its behavior in sequential *** this paper,a comprehensive review on object tracking stages and computational methods that are utilized in terms of cell tracking has been ***,the available software packages and toolkits,challenges,and their solution in time lapse microscopy images in this scope were *** aim of describing computational cell tracking methods and tools is that biologist and cell scientists might take advantage of these computational techniques to find another method to gain complementary information for their question of interest.

关键词： Cell tracking Digital cell tracking Live-cell microscopy Image analysis Bioimage informatics Subcellular location

Stone column settlement performance in structured anisotropic clays:the influence of creep

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2016年第5期8卷 672-688页

作者： Brian G.Sexton Bryan A.McCabe Minna Karstunen Nallathamby Sivasithamparam College of Engineering and informatics National University of Ireland Department of Civil and Environmental Engineering Chalmers University of Technology computational Geomechanics Division Norwegian Geotechnical Institute

The recently developed elasto-viscoplastic Creep-SCLAY1S model has been used in conjunction with PLAXIS 2D to investigate the effectiveness of vibro-replacement in a creep-prone clay. The Creep-SCLAY1S model accounts for anisotropy, bonding, and destructuration, and uses the concept of a constant rate of viscoplastic multiplier to calculate creep strain rate. A comparison of settlement improvement factors with and without creep indicates that ‘total’ settlement improvement factors （primary plus creep） are lower than their ‘primary’ counterparts （primary settlement only）. The lowest settlement improvement factors arise for analyses incorporating the effect of bonding and destructuration. Examination of the variations of vertical stress with time and depth has indicated that vertical stress is transferred from the soil to the column as the soil creeps. This results in additional column yielding. In addition, the radial and hoop stresses in the soil are lower for the ‘creep’ case. The reduced radial stresses lead to additional column bulging and hence more settlement, whereas the hoop stress reductions appear to be a secondary effect, caused by additional plastic deformation for the ‘creep’ case.

关键词： Stone columns Creep Anisotropy Destructuration Finite element (FE) method

Optical nuclear spin polarization in quantum dots

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第10期25卷 535-539页

作者：李爱仙段素青张伟 Institute of Applied Physics and computational Mathematics

Hyperfine interaction between electron spin and randomly oriented nuclear spins is a key issue of electron coherence for quantum information/computation. We propose an efficient way to establish high polarization of nuclear spins and reduce the intrinsic nuclear spin fluctuations. Here, we polarize the nuclear spins in semiconductor quantum dot(QD) by the coherent population trapping(CPT) and the electric dipole spin resonance(EDSR) induced by optical fields and ac electric fields. By tuning the optical fields, we can obtain a powerful cooling background based on CPT for nuclear spin polarization. The EDSR can enhance the spin flip–flop rate which may increase the cooling efficiency. With the help of CPT and EDSR, an enhancement of 1300 times of the electron coherence time can be obtained after a 10-ns preparation time.

关键词： nuclear spin polarization coherent population trapping electron dipole spin resonance

ACCELERATION METHODS OF NONLINEAR ITERATION FOR NONLINEAR PARABOLIC EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Journal of computational Mathematics 2006年第3期24卷 412-424页

作者： Guang-wei Yuan Xu-deng Hang Laboratory of computational Physics Institute of Applied Physics and Computational Mathematics P.O.Box 8009 Beijing 100088 China

This paper discusses the accelerating of nonlinear parabolic equations. Two iterative methods for solving the implicit scheme new nonlinear iterative methods named by the implicit-explicit quasi-Newton （IEQN） method and the derivative free implicit-explicit quasi-Newton （DFIEQN） method are introduced, in which the resulting linear equations from the linearization can preserve the parabolic characteristics of the original partial differential equations. It is proved that the iterative sequence of the iteration method can converge to the solution of the implicit scheme quadratically. Moreover, compared with the Jacobian Free Newton-Krylov （JFNK） method, the DFIEQN method has some advantages, e.g., its implementation is easy, and it gives a linear algebraic system with an explicit coefficient matrix, so that the linear （inner） iteration is not restricted to the Krylov method. computational results by the IEQN, DFIEQN, JFNK and Picard iteration methods are presented in confirmation of the theory and comparison of the performance of these methods.

关键词： Nonlinear parabolic equations Difference scheme Newton iterative methods.