检索结果-南通市图书馆

Oscillatory Dynamics of Heterogeneous Stem Cell Regeneration

在线全文

学校读者我要写书评

暂无评论

Communications on applied Mathematics and Computation 2024年第1期6卷 431-453页

作者： Xiyin Liang Jinzhi Lei School of mathematical sciences Center for Applied MathematicsTiangong UniversityTianjin300387China

Stem cell regeneration is an essential biological process in the maintenance of tissue homeostasis;dysregulation of stem cell regeneration may result in dynamic diseases that show oscillations in cell numbers.Cell heterogeneity and plasticity are necessary for the dynamic equilibrium of tissue homeostasis;however,how these features may affect the oscillatory dynamics of the stem cell regeneration process remains poorly understood.Here,based on a mathematical model of heterogeneous stem cell regeneration that includes cell heterogeneity and random transition of epigenetic states,we study the conditions to have oscillation solutions through bifurcation analysis and numerical simulations.Our results show various model system dynamics with changes in different parameters associated with kinetic rates,cellular heterogeneity,and plasticity.We show that introducing heterogeneity and plasticity to cells can result in oscillation dynamics,as we have seen in the homogeneous stem cell regeneration system.However,increasing the cell heterogeneity and plasticity intends to maintain tissue homeostasis under certain conditions.The current study is an initiatory investigation of how cell heterogeneity and plasticity may affect stem cell regeneration dynamics,and many questions remain to be further studied both biologically and mathematically.

关键词： Stem cell regeneration Heterogenous Hopf bifurcation Hematopoietic dynamical disease

Compressed Data Separation via ?q-Split Analysis with ?∞-Constraint

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

Acta Mathematica Sinica,English Series 2024年第7期40卷 1655-1673页

作者： Ming Yang GU Song LI Jun Hong LIN School of mathematical science Zhejiang University center for Data science Zhejiang University

In this paper, we study compressed data separation（CDS） problem, i.e., sparse data separation from a few linear random measurements. We propose the nonconvex ?q-split analysis with ?∞-constraint and 0 < q ≤ 1. We call the algorithm ?q-split-analysis Dantzig selector（?q-split-analysis DS）. We show that the two distinct subcomponents that are approximately sparse in terms of two different dictionaries could be stably approximated via the ?q-split-analysis DS, provided that the measurement matrix satisfies either a classical D-RIP（Restricted Isometry Property with respect to Dictionaries and ?2norm） or a relatively new（D, q）-RIP（RIP with respect to Dictionaries and ?q-quasi norm） condition and the two different dictionaries satisfy a mutual coherence condition between them.For the Gaussian random measurements, the measurement number needed for the（D, q）-RIP condition is far less than those needed for the D-RIP condition and the（D, 1）-RIP condition when q is small enough.

关键词： Data separation ℓ q -split analysis Dantzig selector frames restricted isometry property compressed sensing 94A12 41A29 65T99 94A20

Revealing excited states of rotational Bose-Einstein condensates

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The Innovation 2024年第1期5卷 41-48页

作者： Jianyuan Yin Zhen Huang Yongyong Cai Qiang Du Lei Zhang School of mathematical sciences Laboratory of Mathematics and Applied MathematicsPeking UniversityBeijing 100871China Department of Mathematics National University of SingaporeSingapore 119076Singapore Department of Mathematics University of CaliforniaBerkeleyBerkeleyCA 94720USA School of mathematical sciences Beijing Normal UniversityBeijing 100875China Department of applied Physics and applied Mathematics and Data science Institute Columbia UniversityNew YorkNY 10027USA Beijing International center for mathematical Research Center for Quantitative BiologyCenter for Machine Learning ResearchPeking UniversityBeijing 100871China

Rotational Bose-Einstein condensates can exhibit quantized vortices as topological excitations.In this study,the ground and excited states of the rotational Bose-Einstein condensates are systematically studied by calculating the stationary points of the Gross-Pitaevskii energy functional.Various excited states and their connections at different rotational frequencies are revealed in solution landscapes constructed with the constrained high-index saddle dynamics method.Four excitation mechanisms are identified:vortex addition,rearrangement,merging,and splitting.We demonstrate changes in the ground state with increasing rotational frequencies and decipher the evolution of the stability of ground states.

关键词： method rotational excited

Alleviating limit cycling in training GANs with an optimization technique

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

science China Mathematics 2024年第6期67卷 1287-1316页

作者： Keke Li Liping Tang Xinmin Yang National center for applied Mathematics in Chongqing Chongqing Normal UniversityChongqing401331China School of mathematical sciences University of Electronic Science and Technology of ChinaChengdu611731China

In this paper,we undertake further investigation to alleviate the issue of limit cycling behavior in training generative adversarial networks(GANs)through the proposed predictive centripetal acceleration algorithm(PCAA).Specifically,we first derive the upper and lower complexity bounds of PCAA for a general bilinear game,with the last-iterate convergence rate notably improving upon previous results.Then,we combine PCAA with the adaptive moment estimation algorithm(Adam)to propose PCAA-Adam,for practical training of GANs to enhance their generalization capability.Finally,we validate the effectiveness of the proposed algorithm through experiments conducted on bilinear games,multivariate Gaussian distributions,and the CelebA dataset,respectively.

关键词： GANs general bilinear game predictive centripetal acceleration algorithm lower and upper complexity bounds PCAA-Adam

Weak type(1, 1) of the Riesz transform on some direct product manifolds with exponential volume growth

在线全文

学校读者我要写书评

暂无评论

science China Mathematics 2024年第7期67卷 1599-1622页

作者： Hong-Quan Li Jie-Xiang Zhu School of mathematical sciences Fudan UniversityShanghai200433China center for applied Mathematics Tianjin UniversityTianjin300072China

In this paper, we are concerned with the Riesz transform on the direct product manifold H^(n)× M,where H^(n) is the n-dimensional real hyperbolic space, and M is a connected complete non-compact Riemannian manifold satisfying the volume doubling property and generalized Gaussian or sub-Gaussian upper estimates for the heat kernel. We establish its weak type(1, 1) property. In addition, we obtain the weak type(1, 1) of the heat maximal operator in the same setting. Our arguments also work for a large class of direct product manifolds with exponential volume growth. Particularly, we provide a simpler proof of weak type(1, 1) boundedness of some operators considered in the work of Li et al.(2016).

关键词： Riesz transform heat kernel direct product real hyperbolic space

Rogue waves for the(2+1)-dimensional Myrzakulov–Lakshmanan-IV equation on a periodic background

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 32-42页

作者： Xiao-Hui Wang Zhaqilao College of Mathematics science Inner Mongolia Normal UniversityHohhot 010022China Laboratory of Infinite-dimensional Hamiltonian System and Its algorithm Application Hohhot 010022China center for applied mathematical science Inner MongoliaHohhot 010022China

In this paper,the rogue wave solutions of the(2+1)-dimensional Myrzakulov–Lakshmanan(ML)-IV equation,which is described by five component nonlinear evolution equations,are studied on a periodic background.By using the Jacobian elliptic function expansion method,the Darboux transformation(DT)method and the nonlinearization of the Lax pair,two kinds of rogue wave solutions which are expressed by Jacobian elliptic functions dn and cn,are obtained.The relationship between these five kinds of potential is summarized systematically.Firstly,the periodic rogue wave solution of one potential is obtained,and then the periodic rogue wave solutions of the other four potentials are obtained directly.The solutions we find present the dynamic phenomena of higher-order nonlinear wave equations.

关键词： rogue waves on a periodic background (2+1)-dimensional Myrzakulov-Lakshmanan-IV equation Darboux transformation Jacobian elliptic function

Point defects in 2-D liquid crystals with a singular potential: Profiles and stability

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

science China Mathematics 2024年

作者： Zhiyuan Geng Wei Wang Basque center for applied Mathematics School of mathematical sciences Zhejiang University

We study radial symmetric point defects with degreek2in the 2-D disk or R2in the Q-tensor framework with a singular bulk energy, which is defined by Bingham closure. First, we obtain the existence of solutions for the profiles of radial symmetric point defects with degreek2in the 2-D disk or R2. Then, we prove that the solution is stable for |k| = 1 and unstable for |k| > 1. Some identities are derived and utilized throughout the proof of existence and stability/instability.

关键词：

Rogue waves for the(2+1)-dimensional Myrzakulov–Lakshmanan-Ⅳ equation on a periodic background

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期 34-44页

作者： Xiao-Hui Wang Zhaqilao College of Mathematics science Inner Mongolia Normal University Laboratory of Infinite-dimensional Hamiltonian System and Its algorithm Application center for applied mathematical science

In this paper, the rogue wave solutions of the(2+1)-dimensional Myrzakulov–Lakshmanan(ML)-Ⅳ equation, which is described by five component nonlinear evolution equations, are studied on a periodic background. By using the Jacobian elliptic function expansion method, the Darboux transformation(DT) method and the nonlinearization of the Lax pair, two kinds of rogue wave solutions which are expressed by Jacobian elliptic functions dn and cn, are obtained.The relationship between these five kinds of potential is summarized systematically. Firstly, the periodic rogue wave solution of one potential is obtained, and then the periodic rogue wave solutions of the other four potentials are obtained directly. The solutions we find present the dynamic phenomena of higher-order nonlinear wave equations.

关键词：

A Composite Ansatz for Calculation of Dynamical Structure Factor

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第1期41卷 92-103页

作者：张玉佩莫崇杰张平康炜 HEDPS Center for Applied Physics and Technologyand School of PhysicsPeking UniversityBeijing 100871China Beijing Computational science Research center Beijing 100193China Institute of applied Physics and Computational Mathematics Beijing 100088China HEDPS Center for Applied Physics and Technologyand College of EngineeringPeking UniversityBeijing 100871China

We propose an ansatz without adjustable parameters for the calculation of a dynamical structure factor.The ansatz combines the quasi-particle Green’s function,especially the contribution from the renormalization factor,and the exchange-correlation kernel from time-dependent density functional theory together,verified for typical metals and semiconductors from a plasmon excitation regime to the Compton scattering regime.It has the capability to reconcile both small-angle and large-angle inelastic x-ray scattering(IXS)signals with muchimproved accuracy,which can be used as the theoretical base model,in inversely inferring electronic structures of condensed matter from IXS experimental signals directly.It may also be used to diagnose thermal parameters,such as temperature and density,of dense plasmas in x-ray Thomson scattering experiments.

关键词： excitation inverse verified