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Structure of multiple solutions for nonlinear differential equations

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Science China Mathematics 2004年第Z1期47卷 172-180页

作者： chen chuanmiao xie ziqing Institute of Computation Hunan Normal University Changsha 410081 China Institute of Computation Hunan Normal University Changsha 410081 China

Based on the eigensystem {λj,φjof -Δ, the multiple solutions for nonlinear problem Δu+f(u)=0 in Ω,u=0 onαΩ are approximated. A new search-extension method (SEM), which consists of three steps in three level subspaces, is proposed. Numerical simulations for several typical nonlinear cases, i.e. f(u)=u3,u2(u-p),u2(u2-p), are completed and some conjectures are presented.

关键词： nonlinear problem, multiple solutions, search-extension method, structure, conjecture.

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非线性问题多解逼近研究与激光应用

湖南师范大学自然科学学报 1999年第1期22卷 1-5页

作者：陈传淼谢资清湖南师范大学计算机研究所

为研究激光发射的机理，用特征函数展开方法寻求非线性Ｓｃｈｒｏｄｉｎｇｅｒ方程的多重解，对多解的分布与结构作了初步的描述．提出了一个有效的双向迭代格式，并得到了满意的数值结果．

关键词：多重解逼近非线性问题激光薛定谔方程

Analysis of search-extension method for finding multiple solutions of nonlinear problem

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Science China Mathematics 2008年第1期51卷 42-54页

作者： chen chuanmiao xie ziqing Institute of Computation Hunan Normal UniversityChangsha410081 China

For numerical computations of multiple solutions of the nonlinear elliptic problem Δu + f(u = 0 in Ω, u = 0 on Γ, a search-extension method (SEM) was proposed and systematically studied by the authors. This paper shall complete its theoretical analysis. It is assumed that the nonlinearity is non-convex and its solution is isolated, under some conditions the corresponding linearized problem has a unique solution. By use of the compactness of the solution family and the contradiction argument, in general conditions, the high order regularity of the solution u ∈ H 1+α, α > 0 is proved. Assume that some initial value searched by suitably many eigenbases is already fallen into the neighborhood of the isolated solution, then the optimal error estimates of its nonlinear finite element approximation are shown by the duality argument and continuation method.

关键词： nonlinear isolated solution regularity search-extension finite elements error analysis 65N30

Experimental Study on Geometry Characteristics of Turbulent Premixed Flames for Natural Gas/Air Mixtures

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Journal of Thermal Science 2025年第1期34卷 268-282页

作者： ZHENG Weilin WANG Qijiao XIAO Huahua chen Xiaoxiao xie Fan ZENG Wen Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System Shenyang Aerospace University State Key Laboratory of Fire Science University of science and Technology of China AVIC Shenyang Aircraft Design and Research Institute

In this study,focusing on the geometry characteristics of spherical expanding flame,the turbulent premixed flames of natural gas/air mixtures were investigated in a fan-stirred turbulent *** effects of initial temperature（T=300-400 K）,initial pressure（P=0.1-0.3 MPa）,turbulence intensity（u'=1.0-2.7 m/s）,oxygen volumetric percentage(φ（O2）=15%-21%) and carbon dioxide volumetric percentage(φ（CO2）=0-20%)were delved *** flame profile under the Cartesian coordinate system was derived from the schlieren images taken by the high-speed ***,from both macroscopic and microscopic perspectives,the influence of experimental conditions on the flame geometry characteristics was explored through flame front extraction,wavelet decomposition and network *** results demonstrate that for significant flame wrinkling,changes in species concentrations and turbulence intensity have more pronounced effects on the flame wrinkling *** wrinkling of the flame front maintains a certain degree of similarity,as evidenced by the locally concentrated distribution of the angles of the maximum fluctuation *** disturbance energy under large-scale（D6-D8） disturbances exhibits relatively high values with a similar trend,exerting a significant impact on the geometry characteristics of the flame *** peaks of correlation degree are scattered either with the decomposition scale or the development of flame radius,indicating no linear correlation between different detail ***,the probability distribution of node degrees in key wrinkled regions exhibits different trends with that of large-scale wrinkling and disturbance energy,especially with changes in initial *** occurs because the number of key wrinkles varies based on the perturbation's strength or the region's ***,an increase in the fluctuation frequency of the flame's local radius may not necessarily lead to an increase in the number of key folded regions.

关键词： fan-stirred turbulent combustor geometry characteristics large-scale wrinkling network topology wavelet decomposition

Multi-layer multi-pass friction rolling additive manufacturing of Al alloy:Toward complex large-scale high-performance components

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 425-438页

作者： Haibin Liu Run Hou chenghao Wu Ruishan xie Shujun chen College of Mechanical&Energy Engineering Beijing University of TechnologyBeijing 100124China Chongqing Research Institute of Beijing University of Technology Chongqing 401121China

At present,the emerging solid-phase friction-based additive manufacturing technology,including friction rolling additive man-ufacturing(FRAM),can only manufacture simple single-pass *** this study,multi-layer multi-pass FRAM-deposited alumin-um alloy samples were successfully prepared using a non-shoulder tool *** material flow behavior and microstructure of the over-lapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition were studied using the hybrid 6061 and 5052 aluminum *** results showed that a mechanical interlocking structure was formed between the adjacent layers and the adja-cent passes in the overlapped center *** friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone,which made the recrystallization degree in the left and right edge zones of the over-lapped zone the highest,followed by the overlapped center zone and the non-overlapped *** tensile strength of the overlapped zone exceeded 90%of that of the single-pass deposition *** is proved that although there are uneven grooves on the surface of the over-lapping area during multi-layer and multi-pass deposition,they can be filled by the flow of materials during the deposition of the next lay-er,thus ensuring the dense microstructure and excellent mechanical properties of the overlapping *** multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.

关键词： aluminum alloy additive manufacturing solid-state friction stir welding multi-layer multi-pass

Implicit DG Method for Time Domain Maxwell’s Equations Involving Metamaterials

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Advances in Applied Mathematics and Mechanics 2015年第6期7卷 796-817页

作者： Jiangxing Wang ziqing xie chuanmiao chen Key Laboratory of High Performance Computing and Stochastic Information Processing College of Mathematics and Computer ScienceHunan Normal UniversityChangsha 410081China

An implicit discontinuous Galerkin method is introduced to solve the timedomain Maxwell’s equations in *** Maxwell’s equations in metamaterials are represented by integral-differential *** scheme is based on discontinuous Galerkin method in spatial domain and Crank-Nicolson method in temporal *** fully discrete numerical scheme is proved to be unconditionally *** polynomial of degree at most p is used for spatial approximation,our scheme is verified to converge at a rate of O(τ^(2)+h^(p)+1/2).Numerical results in both 2D and 3D are provided to validate our theoretical prediction.

关键词： Maxwell’s equations metamaterials fully disctete DG method L2-stability L2-error estimate.

High-throughput screening of CO_(2) cycloaddition MOF catalyst with an explainable machine learning model

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Green Energy & Environment 2025年第1期10卷 132-138页

作者： Xuefeng Bai Yi Li Yabo xie Qiancheng chen Xin Zhang Jian-Rong Li Beijing Key Laboratory for Green Catalysis and Separation and Department of Chemical Engineering College of Materials Science&EngineeringBeijing University of TechnologyBeijing100124China

The high porosity and tunable chemical functionality of metal-organic frameworks(MOFs)make it a promising catalyst design ***-throughput screening of catalytic performance is feasible since the large MOF structure database is *** this study,we report a machine learning model for high-throughput screening of MOF catalysts for the CO_(2) cycloaddition *** descriptors for model training were judiciously chosen according to the reaction mechanism,which leads to high accuracy up to 97%for the 75%quantile of the training set as the classification *** feature contribution was further evaluated with SHAP and PDP analysis to provide a certain physical understanding.12,415 hypothetical MOF structures and 100 reported MOFs were evaluated under 100℃ and 1 bar within one day using the model,and 239 potentially efficient catalysts were *** them,MOF-76(Y)achieved the top performance experimentally among reported MOFs,in good agreement with the prediction.

关键词： Metal-organic frameworks High-throughput screening Machine learning Explainable model CO_(2)cycloaddition

Advances in Graphene‑Based Electrode for Triboelectric Nanogenerator

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Nano-Micro Letters 2025年第1期17卷 378-403页

作者： Bin xie Yuanhui Guo Yun chen Hao Zhang Jiawei Xiao Maoxiang Hou Huilong Liu Li Ma Xin chen Chingping Wong State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006People’s Republic of China School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006People’s Republic of China School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

With the continuous development of wearable electronics,wireless sensor networks and other micro-electronic devices,there is an increasingly urgent need for miniature,flexible and efficient nanopower generation *** nanogenerator(TENG)technology can convert small mechanical energy into electricity,which is expected to address this *** the core component of TENG,the choice of electrode materials significantly affects its *** metal electrode materials often suffer from problems such as durability,which limits the further application of ***,as a novel electrode material,shows excellent prospects for application in TENG owing to its unique structure and excellent electrical *** review systematically summarizes the recent research progress and application prospects of TENGs based on graphene *** precision processing methods of graphene electrodes are introduced,and the applications of graphene electrode-based TENGs in various scenarios as well as the enhancement of graphene electrodes for TENG performance are *** addition,the future development of graphene electrode-based TENGs is also prospectively discussed,aiming to promote the continuous advancement of graphene electrode-based TENGs.

关键词： Triboelectric nanogenerator Precision processing Graphene electrode Self-powered sensor

AZD1775 synergizes with SLC7A11 inhibition to promote ferroptosis

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Science China Life Sciences 2025年第1期68卷 204-218页

作者： chen Xiong Hong Ling Yingdan Huang Hanzhi Dong Bangxiang xie Qian Hao Xiang Zhou Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences Fudan University Department of Oncology Shanghai Medical CollegeFudan University Department of Breast Surgery Fudan University Shanghai Cancer CenterFudan University Department of Oncology First Affiliated Hospital of Nanchang University Beijing Institute of Hepatology Beijing Youan HospitalCapital Medical University Beijing Engineering Research Center for Precision Medicine and Transformation of Hepatitis and Liver Cancer Key Laboratory of Breast Cancer in Shanghai Fudan University Shanghai Cancer CenterFudan University Shanghai Key Laboratory of Medical Epigenetics International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology)Institutes of Biomedical SciencesFudan University

Tumor suppressor p53-mediated cell cycle arrest and DNA damage repair may exert cytoprotective effects against cancer therapies, including WEE1 inhibition. Considering that p53 activation can also lead to multiple types of cell death, the role of this tumor suppressor in WEE1 inhibitor-based therapies remains disputed. In this study, we reported that nucleolar stress-mediated p53 activation enhanced the WEE1 inhibitor AZD1775-induced ferroptosis to suppress lung cancer growth. Our findings showed that AZD1775 promoted ferroptosis by blocking cystine uptake, an action similar to that of Erastin. Meanwhile, inhibition of WEE1 by the WEE1 inhibitors or si RNAs induced compensatory upregulation of SLC7A11, which conferred resistance to ferroptosis. Mechanistically, AZD1775 prevented the enrichment of H3K9me3, a histone marker of transcriptional repression, on the SLC7A11 promoter by repressing the expression of the histone methyltransferase SETDB1, thereby enhancing NRF2-mediated SLC7A11 transcription. This finding was also validated using the H3K9me3 inhibitor BRD4770. Remarkably, we found that the nucleolar stress-inducing agent Actinomycin D(Act. D) inhibited SLC7A11 expression by activating p53, thus augmenting AZD1775-induced ferroptosis. Moreover, the combination of AZD1775 and Act. D synergistically suppressed wild-type p53-harboring lung cancer cell growth both in vitro and in vivo. Altogether, our study demonstrates that AZD1775 promotes ferroptosis by targeting cystine uptake but also mediates the adaptive activation of SLC7A11 through the WEE1-SETDB1 cascade and NRF2-induced transcription, and inhibition of SLC7A11 by Act. D boosts the anti-tumor efficacy of AZD1775 by enhancing ferroptosis in cancers with wild-type p53.

关键词： p53 NRF2 SLC7A11 WEE1 AZD1775 ferroptosis nucleolar stress