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Science China Mathematics 2024年第12期67卷 2873-2898页

作者： Xinping Gui buyang li Jilu Wang Beijing Computational Science Research Center Beijing 100193China Department of Applied Mathematics The Hong Kong Polytechnic UniversityHong KongChina School of Science Harbin Institute of TechnologyShenzhen 518055China

A class of stochastic Besov spaces BpL^(2)(Ω;˙H^(α)(O)),1≤p≤∞andα∈[−2,2],is introduced to characterize the regularity of the noise in the semilinear stochastic heat equation du−Δudt=f(u)dt+dW(t),under the following conditions for someα∈(0,1]:||∫_(0)^(t)e−(t−s)^(A)dW(s)||L^(2)(Ω;L^(2)(O))≤C^(t^(α/2))and||∫_(0)^(t)e−(t−s)^(A)dW(s)||_B^(∞)L^(2)(Ω:H^(α)(O))≤C..The conditions above are shown to be satisfied by both trace-class noises(withα=1)and one-dimensional space-time white noises(withα=1/2).The latter would fail to satisfy the conditions withα=1/2 if the stochastic Besov norm||·||B∞L^(2)(Ω;˙H^(α)(O))is replaced by the classical Sobolev norm||·||L^(2)(Ω;˙Hα(O)),and this often causes reduction of the convergence order in the numerical analysis of the semilinear stochastic heat *** this paper,the convergence of a modified exponential Euler method,with a spectral method for spatial discretization,is proved to have orderαin both the time and space for possibly nonsmooth initial data in L^(4)(Ω;˙H^(β)(O))withβ>−1,by utilizing the real interpolation properties of the stochastic Besov spaces and a class of locally refined stepsizes to resolve the singularity of the solution at t=0.

关键词： semilinear stochastic heat equation additive noise space-time white noise exponential Euler method spectral method strong convergence stochastic Besov space real interpolation

The Stability and Convergence of Fully Discrete Galerkin-Galerkin FEMs for Porous Medium Flows

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Communications in Computational Physics 2014年第4期15卷 1141-1158页

作者： buyang li Jilu Wang Weiwei Sun Department of Mathematics Nanjing UniversityNanjingP.R.China Department of Mathematics City University of Hong KongKowloonHong Kong

The paper is concerned with the unconditional stability and error estimates of fully discrete Galerkin-Galerkin FEMs for the equations of incompressible miscible flows in porous *** prove that the optimal L 2 error estimates hold without any time-step(convergence)conditions,while all previous works require certain time-step *** analysis is based on a splitting of the error into two parts:the error from the time discretization of the PDEs and the error from the finite element discretization of the corresponding time-discrete PDEs,which was proposed in our previous work[26,27].Numerical results for both two and three-dimensional flow models are presented to confirm our theoretical analysis.

关键词： Unconditional stability optimal error estimate Galerkin FEMs incompressible miscible flows

High-Order Fully Discrete Energy Diminishing Evolving Surface Finite Element Methods for a Class of Geometric Curvature Flows

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Annals of Applied Mathematics 2021年第4期37卷 405-436页

作者： Beiping Duan buyang li Zhimin Zhang Beijing Computational Science Research Center Beijing 100193China Shenzhen JL Computational Science and Applied Research Institute ShenzhenGuangdong 518129China Department of Applied Mathematics The Hong Kong Polytechnic UniversityHung HornHong KongChina Department of Mathematics Wayne State UniversityDetroitMI 48202USA

This article concerns the construction of high-order energy-decaying numerical methods for gradient flows of evolving surfaces with curvature-dependent energy *** semidiscrete evolving surface finite element method is derived based on the calculus of variation of the semidiscrete surface energy *** makes the semidiscrete problem naturally inherit the energy decay *** this property,the semidiscrete problem is furthermore formulated as a gradient flow system of *** averaged vector-field collocation method is used for time discretization of the ODEs to preserve energy decay at the fully discrete level while achieving high-order accuracy in *** numerical examples are provided to illustrate the accuracy and energy diminishing property of the proposed method,as well as the effectiveness of the method in capturing singularities in the evolution of closed surfaces.

关键词： Gradient flow evolving surface curvature energy decay evolving surface finite element method averaged vector-field collocation

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曲率流的参数化有限元逼近

计算数学 2022年第2期44卷 145-162页

作者：李步扬香港理工大学应用数学系中国

许多物理现象可以在数学上描述为受曲率驱动的自由界面运动,例如薄膜和泡沫的演变、晶体生长,等等.这些薄膜和界面的运动常依赖于其表面曲率,从而可以用相应的曲率流来描述,其相关自由界面问题的数值计算和误差分析一直是计算数学领域... 详细信息

许多物理现象可以在数学上描述为受曲率驱动的自由界面运动,例如薄膜和泡沫的演变、晶体生长,等等.这些薄膜和界面的运动常依赖于其表面曲率,从而可以用相应的曲率流来描述,其相关自由界面问题的数值计算和误差分析一直是计算数学领域中的难点.参数化有限元法是曲率流的一类有效计算方法,已经能够成功模拟一些曲面在几类基本的曲率流下的演化过程.本文重点讨论曲率流的参数化有限元逼近,它的产生、发展和当前的一些挑战.

关键词：自由界面曲率流非线性参数化有限元演化有限元保几何结构切向速度网格均匀化收敛性误差估计

热方程的一些端点估计及其在Navier-Stokes方程中的应用

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中国科学：数学 2014年第5期44卷 423-434页

作者：曹政子李步扬孙永忠南京大学数学系南京210093

本文首先讨论热方程初值问题的解在Hardy、BMO(bounded mean oscillation)和Besov型空间中的估计.然后本文结合Coifmann-lions-Meyer-Semmes在Hardy空间中的补偿紧性结果,给出Navier-Stokes方程整体弱解的二阶导数的一些端点估计.

关键词： Hardy空间 BMO空间 Besov空间热方程 Navier-Stokes方程

气相色谱内标法测定小儿痱子洗剂中薄荷脑的含量

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甘肃医药 2017年第12期36卷 997-999页

作者：李步阳江苏省中医药研究院江苏南京210028

目的:建立小儿痱子洗剂中薄荷脑含量的检测标准,为药品质量控制提供依据。方法:采用气相色谱法,以萘为内标物,仪器使用岛津SP-2100气相色谱仪。色谱柱:聚乙二醇PEG-20M毛细管色谱柱(30m×0.25mm×0.25μm);柱温:程序升温,初始温度为110... 详细信息

目的:建立小儿痱子洗剂中薄荷脑含量的检测标准,为药品质量控制提供依据。方法:采用气相色谱法,以萘为内标物,仪器使用岛津SP-2100气相色谱仪。色谱柱:聚乙二醇PEG-20M毛细管色谱柱(30m×0.25mm×0.25μm);柱温:程序升温,初始温度为110℃,保持15min,以每分钟10℃的速率升至150℃,保持3min;FID检测器,检测器温度:220℃;载气:氮气;氮气流速:30ml/min;直接进样,进样体积:1μl;分流进样,分流比为10:1。结果:薄荷脑在浓度范围0.051~1.020mg/ml内线性关系良好,线性方程为Y=0.90427X-0.01357(r=0.9996),本品的加样回收率为94.57%~100.73%,RSD=2.03%。结论:气相色谱内标法简便、快速、准确,可用于小儿痱子洗剂质量控制。

关键词：小儿痱子洗剂薄荷脑气相色谱内标法含量测定

基于肠道菌群探讨甘草泻心汤对伊立替康致小鼠腹泻的影响

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药物评价研究 2023年第7期46卷 1497-1505页

作者：聂彦丰范永春郭双双李步阳邳州市中医院江苏徐州221300 江苏省中医药研究院江苏南京210028

目的研究甘草泻心汤对化疗相关腹泻小鼠肠道菌群的影响。方法将小鼠随机分为对照组、模型组、洛哌丁胺(阳性药,0.4 mg·kg^(-1))组和甘草泻心汤高、低剂量(16.4、4.1 g·kg^(-1))组;采用连续4 d ip 55 mg·kg^(-1)伊立替康诱导小鼠化... 详细信息

目的研究甘草泻心汤对化疗相关腹泻小鼠肠道菌群的影响。方法将小鼠随机分为对照组、模型组、洛哌丁胺(阳性药,0.4 mg·kg^(-1))组和甘草泻心汤高、低剂量(16.4、4.1 g·kg^(-1))组;采用连续4 d ip 55 mg·kg^(-1)伊立替康诱导小鼠化疗相关腹泻模型;记录小鼠首次排便时间、稀便级、稀便率和腹泻指数;采用试剂盒测定小鼠肠道消化酶活力及炎症因子水平;采用高通量测序技术分析结肠内容物肠道菌群变化。结果与对照组比较,模型组小鼠首次排便时间显著缩短(P<0.01),稀便级、稀便率和腹泻指数显著升高(P<0.01);消化酶乳酸脱氢酶(LDH)、淀粉酶(AMS)和脂肪酶(LPS)活力显著降低(P<0.01);炎症因子白细胞介素1β(IL-1β)、环氧化酶2(COX-2)、细胞间黏附分子1(ICAM-1)和肿瘤坏死因子α(TNF-α)水平显著升高(P<0.01);肠道菌群α多样性Simpson指数显著升高(P<0.05);肠道菌群β多样性差异较大;变形菌门、梭杆菌门、变形菌纲、梭杆菌纲、肠杆菌目、梭杆菌目、拟杆菌科、丹毒丝菌科、埃格特菌科和拟杆菌属丰度显著升高(P<0.01),Muribaculaceae和norank_f__Muribaculaceae丰度显著降低(P<0.01)。与模型组比较,甘草泻心汤高、低剂量组小鼠首次排便时间显著延长(P<0.05、0.01)、稀便率和腹泻指数显著降低(P<0.05、0.01),高剂量组稀便级显著降低(P<0.01);高、低剂量组各消化酶活力显著回升(P<0.05、0.01);高、低剂量组各炎症因子水平显著降低(P<0.05、0.01);高剂量组Simpson指数显著降低(P<0.05),β多样性更趋近对照组,显著回调各优势物种丰度的显著性变化(P<0.05、0.01)。结论甘草泻心汤对于伊立替康诱导的腹泻小鼠具有明显的治疗作用,可能是其通过调整腹泻小鼠肠道菌群实现。

关键词：甘草泻心汤化疗相关腹泻伊立替康高通量测序肠道菌群

Constraints on holographic QCD phase transitions from PTA observations

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 71-78页

作者： Song He li li Sai Wang Shao-Jiang Wang Center for Theoretical Physics and College of Physics Jilin University School of Physical Science and Technology Ningbo University Max Planck Institute for Gravitational Physics (Albert Einstein Institute) CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences (UCAS) School of Physical Sciences University of Chinese Academy of Sciences (UCAS) Theoretical Physics Division Institute of High Energy Physics Chinese Academy of Sciences

The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition, yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition(FoPT) left undetermined. At specific baryon chemical potential, the first-order QCD phase transition agrees with the observational constraint of baryon asymmetry. It, therefore, provides a scenario for phase transition gravitational waves(GWs) within the standard model of particle physics. If these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array(PTA) observations, the duration of this FoPT can be well constrained, and the associated primordial black holes are still allowed by current observations.

关键词： pulsar timing array QCD phase transition gravitational waves primordial black holes

Cell polarization in ischemic stroke: molecular mechanisms and advances

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Neural Regeneration Research 2025年第3期20卷 632-645页

作者： Yuanwei li Xiaoxiao Xu Xuan Wu Jiarui li Shiling Chen Danyang Chen Gaigai li Zhouping Tang Department of Neurology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei ProvinceChina

Ischemic stroke is a cerebrovascular disease associated with high mortality and disability rates. Since the inflammation and immune response play a central role in driving ischemic damage, it becomes essential to modulate excessive inflammatory reactions to promote cell survival and facilitate tissue repair around the injury site. Various cell types are involved in the inflammatory response, including microglia, astrocytes, and neutrophils, each exhibiting distinct phenotypic profiles upon stimulation. They display either proinflammatory or anti-inflammatory states, a phenomenon known as ‘cell polarization.’ There are two cell polarization therapy strategies. The first involves inducing cells into a neuroprotective phenotype in vitro, then reintroducing them autologously. The second approach utilizes small molecular substances to directly affect cells in vivo. In this review, we elucidate the polarization dynamics of the three reactive cell populations(microglia, astrocytes, and neutrophils) in the context of ischemic stroke, and provide a comprehensive summary of the molecular mechanisms involved in their phenotypic switching. By unraveling the complexity of cell polarization, we hope to offer insights for future research on neuroinflammation and novel therapeutic strategies for ischemic stroke.

关键词： astrocyte polarization immune regulation inflammation ischemic injury microglia polarization neutrophil polarization signaling pathways stroke

Design of a cationic accelerator enabling ultrafast ion diffusion kinetics in aqueous zinc-ion batteries

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Journal of Energy Chemistry 2025年第1期100卷 377-384页

作者： Yawei Xiao Qianqian Gu Haoyu li Mengyao li Yude Wang National Center for International Research on Photoelectric and Energy Materials School of Materials and Energy Yunnan University Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources School of Chemistry and Chemical Engineering Hainan University College of Chemical Engineering Fuzhou University Yunnan Key Laboratory of Carbon Neutrality and Green Low-carbon Technologies Yunnan University

Aqueous zinc-ion batteries are highly favored for grid-level energy storage owing to their low cost and high safety,but their practical application is limited by slow ion *** address this,a strategy has been developed to create a cation-accelerating electric field on the surface of the cathode to achieve ultrafast Zn2+diffusion *** employing electrodeposition to coat MoS2on the surface of BaV6O16·3H2O nanowires,the directional built-in electric field generated at the heterointerface acts as a cation accelerator,continuously accelerating Zn2+diffusion into the active *** optimized Zn2+diffusion coefficient in CC@BaV-6O16·3H2O@MoS2(7.5×10～8cm2s-1) surpasses that of most reported V-based ***,MoS2serving as a cathodic armor extends the cycling life of the Zn-CC@BaV6O16·3H2O@MoS2full batteries to over 10000 *** work provides valuable insights into optimizing ion diffusion kinetics for high-performance energy storage devices.

关键词： Internal electric field Cationic accelerator Ion diffusion kinetics Cathode modification strategy Aqueous zinc ion battery