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Acta Mathematicae Applicatae Sinica 2023年第2期39卷 396-423页

作者： Hao CHANG xing-jiang chen School of Mathematical Sciences Tiangong UniversityTianjin 300387China Department of Mathematical Sciences School of EngineeringComputer and Mathematical SciencesAuckland University of TechnologyAucklandNew Zealand

This paper studies a defined contribution(DC)pension fund investment problem with return of premiums clauses in a stochastic interest rate and stochastic volatility *** practice,most of pension plans were subject to the return of premiums clauses to protect the rights of pension members who died before *** the mathematical modeling,we assume that a part of pension members could withdraw their premiums if they died before retirement and surviving members could equally share the difference between accumulated contributions and returned *** suppose that the financial market consists of a risk-free asset,a stock,and a zero-coupon *** interest rate is driven by a stochastic affine interest rate model and the stock price follows the Heston’s stochastic volatility model with stochastic interest *** fund managers have different risk preferences,and the hyperbolic absolute risk aversion(HARA)utility function is a general one including a power utility,an exponential utility,and a logarithm utility as special *** are concerned with an optimal portfolio to maximize the expected utility of terminal wealth by choosing the HARA utility function in the *** using the principle of dynamic programming and Legendre transform-dual theory,we obtain explicit solutions of optimal *** special cases are also derived in ***,a numerical simulation is provided to illustrate our results.

关键词： defined contribution pension plan return of premiums clauses stochastic interest rate HARA preference Legendre transform-dual theory stochastic optimal control

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ALUMINA COATINGS PLASMA-SPRAYED AT DIFFERENT SUBSTRATE TEMPERATURES

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Acta Mechanica Solida Sinica 2011年第5期24卷 461-466页

作者： Yazhe xing Chaoping jiang Hong chen Jianmin Hao School of Materials Science and Engineering Chang＇an University Xi＇an 710064 China

Alumina coatings are prepared by atmospheric plasma spraying through controlling the substrate temperature during spraying. The changes in microstructure and mechanical properties of the coatings prepared at different substrate temperatures are examined. The hard-ness and the elastic modulus of the coatings are measured by indentation methods. The results show that interlamellar bonding in the coatings is significantly improved with increasing the substrate temperature. Moreover, long through-thickness columnar grains form in the coatings when the substrate temperature reaches above 430℃. As a result, the cross-sectional hardness and the elastic modulus perpendicular to the coating surface increase with increasing the substrate temperature.

关键词： plasma spraying alumina interlamellar bonding elastic modulus

Electricity resonance-induced phase transition of water confined in nanochannels

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Communications in Theoretical Physics 2024年第5期76卷 159-165页

作者： Yunqiu Ma Zhigao Zhao Shaoqian Hao Jianlong Kou jiang-xing chen Institute of Condensed Matter Physics Zhejiang Institute of Photoelectronics&Zhejiang Institute for Advanced Light SourceZhejiang Normal UniversityJinhua 321004China Department of Physics Inner Mongolia UniversityHohhot 010021China Department of Physics Hangzhou Normal UniversityHangzhou 311121China

The phase transition of water molecules in nanochannels under varying external electric fields is studied by molecular dynamics *** is found that the phase transition of water molecules in nanochannels occurs by changing the frequency of the varying electric *** molecules maintain the ice phase when the frequency of the varying electric field is less than 16 THz or greater than 30 THz,and they completely melt when the frequency of the varying electric field is 24 *** phenomenon is attributed to the breaking of hydrogen bonds when the frequency of the varying electric field is close to their inherent resonant ***,the study demonstrates that the critical frequency varies with the confinement *** new mechanism of regulating the phase transition of water molecules in nanochannels revealed in this study provides a perspective for further understanding of the phase transition of water molecules in nanochannels,and has great application potential in preventing icing and deicing.

关键词： electricity resonance phase transition water molecules molecular dynamics simulations

Transport of nanodimers through chemical microchip

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Communications in Theoretical Physics 2020年第1期72卷 130-134页

作者： Shun Zhan Ru-Fei Cui Li-Yan Qiao jiang-xing chen Department of Physics Hangzhou Dianzi UniversityHangzhou310018China Department of Physics Zhejiang UniversityHangzhou310018China

We propose a new microfluid chip for transporting micro and nano *** device consists of chemical stripe pathways full of fuel species,which can be realized in experiments by chemical surface reactions that form spatiotemporal patterns.A mesoscopic model is constructed to simulate the transport dynamics of nanodimers passing through the *** is found that the increases of the volume fraction and radius of the dimer both decrease the first reach time although the underlying mechanisms are different:the volume fraction affects the probability of touching and entering the chip while the radius determines the self-propulsion within the *** transport efficiency is influenced by the size of the particles.

关键词： microchip catalytically sphere dimers chemical pathway multiparticle collision dynamics transport

Interface water-induced hydrophobic carbon chain unfolding in water

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Communications in Theoretical Physics 2021年第5期73卷 102-110页

作者： Zhang Xie Zheng Li Gang Lou Qing Liang jiang-xing chen Jianlong Kou Gui-Na Wei Institute of Condensed Matter Physics Zhejiang Normal UniversityJinhua 321004China School of Petroleum Engineering China University of Petroleum(East China)Qingdao 266580China Department of Physics Hanghzou Dianzi UniversityHangzhou 310018China Division of Nephrology The Second Affiliated Hospital of Zhejiang UniversitySchool of MedicineHangzhou 310009China

The folding and unfolding of the carbon chain,which is the basic constitutional unit of polymers,are important to the performance of the ***,it is difficult to regulate conformational transition of the carbon chain,especially in an aqueous *** this paper,we propose a strategy to regulate the conformational transition of the carbon chain in water based on the all-atom molecular dynamics *** is shown that the unfolded carbon chain will spontaneously collapse into the folded state,while the folded carbon chain will unfold with an external electric *** regulation ability of the electric field is attributed to the electric field-induced redistribution of interface water molecules near the carbon *** demonstrated method of regulating conformational transition of the carbon chain in water in this study provides an insight into regulating hydrophobic molecules in water,and has great potential in drug molecule design and new polymer material development.

关键词： carbon chain unfolding electric field interface water molecular dynamics simulations

Dynamics of Spiral Waves Induced by Periodic Mechanical Deformation with Phase Difference

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Communications in Theoretical Physics 2018年第12期69卷 749-752页

作者： Peng-Fei Li Li-Yan Qiao Ye-Hua Zhao jiang-xing chen Jun Ma Department of Mathematics Hangzhou Dianzi University Department of Physics Hangzhou Dianzi University Department of Physics Lanzhou University of Technology

The dynamics of spiral waves under the influences of periodic mechanical deformation are studied. Here,the mechanical deformation propagating along the medium with phase differences are considered. It is found that weak mechanical deformation may lead to resonant drift of spiral waves. The drift direction and velocity can be changed by the wave length of the deformation. Strong mechanical deformation may result in breakup of spiral waves. The characteristics of breakup are discussed. The critical amplitudes are determined by two factors, i.e. the wave length and frequency of the periodic mechanical deformation. When the wave length of mechanical deformation is comparable to the spiral wave, simulation shows that the critical amplitude is substantially increased. As the frequency of the mechanical deformation is around 1.5 times of the spiral wave, the critical amplitudes are minimal.

关键词： drift breakup of spiral waves periodic mechanical deformation phase difference

Interaction of Wave Trains with Defects

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Communications in Theoretical Physics 2019年第3期71卷 334-338页

作者： Xian-Wei chen Peng-Fei Li Xiao-Ping Yuan Ye-Hua Zhao Jun Ma jiang-xing chen Department of Public Elementary Education Zhejiang Guangsha College of Applied Construction Technology Department of Physics Hangzhou Dianzi University Information Engineering School Hangzhou Dianzi University Department of Physics Lanzhou University of Technology

The evolution and transition of planar wave trains propagating through defects(obstacles) in an excitable medium are studied. When the frequency of the planar wave trains is increased, three different dynamical regimes,namely fusion, "V" waves, and spiral waves, are observed in turn and the underlying mechanism is discussed. The dynamics is concerned with the shapes of the defects. Circle, triangle, and rectangle defects with different sizes are considered. The increase of pacing frequency broadens the fan-shaped broken region in the behind of a rectangle *** increase of width of a triangle defect leads to breakup of wave trains easier while the change of height shows opposite effect, which is presented in a phase diagram. Dynamical comparison on defects with different shapes indicates that the decrease of the defect width along the propagation of wave trains makes the fan-shaped region and the minimal frequency for breakup of spiral both increased.

关键词： planar wave trains defects, fusion “V” pattern spiral wave

Toward understanding the role of genomic repeat elements in neurodegenerative diseases

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Neural Regeneration Research 2025年第3期20卷 646-659页

作者： Zhengyu An Aidi jiang Jingqi chen Institute of Science and Technology for Brain-Inspired Intelligence Fudan UniversityShanghaiChina MOE Frontiers Center for Brain Science Fudan UniversityShanghaiChina MOE Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence Fudan UniversityShanghaiChina Zhangjiang Fudan International Innovation Center ShanghaiChina

Neurodegenerative diseases cause great medical and economic burdens for both patients and society;however, the complex molecular mechanisms thereof are not yet well understood. With the development of high-coverage sequencing technology, researchers have started to notice that genomic repeat regions, previously neglected in search of disease culprits, are active contributors to multiple neurodegenerative diseases. In this review, we describe the association between repeat element variants and multiple degenerative diseases through genome-wide association studies and targeted sequencing. We discuss the identification of disease-relevant repeat element variants, further powered by the advancement of long-read sequencing technologies and their related tools, and summarize recent findings in the molecular mechanisms of repeat element variants in brain degeneration, such as those causing transcriptional silencing or RNA-mediated gain of toxic function. Furthermore, we describe how in silico predictions using innovative computational models, such as deep learning language models, could enhance and accelerate our understanding of the functional impact of repeat element variants. Finally, we discuss future directions to advance current findings for a better understanding of neurodegenerative diseases and the clinical applications of genomic repeat elements.

关键词： Alzheimer's disease ataxia deep learning long-read sequencing neurodegeneration neurodegenerative diseases Parkinson's disease repeat element structural variant

Miyaoka-type inequalities for terminal threefolds with nef anti-canonical divisors

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Science China Mathematics 2025年第1期68卷 1-18页

作者： Masataka Iwai chen jiang Haidong Liu Department of Mathematics Graduate School of ScienceOsaka University Shanghai Center for Mathematical Sciences & School of Mathematical Sciences Fudan University Department of mathematics Sun Yat-sen University

In this paper,we study Miyaoka-type inequalities on Chern classes of terminal projective 3-folds with nef anti-canonical *** X be a terminal projective 3-fold such that-KXis *** show that if c1（X） · c2（X）≠0,then c1（X） · c2（X） ≥ 1/252;if further X is not rationally connected,then c1（X） · c2（X） ≥ 4/5 and this inequality is *** order to prove this,we give a partial classification of such varieties along with many *** also study the nonvanishing of c1（X）dim X-2· c2（X） for terminal weak Fano varieties and prove a Miyaoka-Kawamata-type inequality.

关键词： terminal threefolds Miyaoka-type inequality boundedness

Exploring the potential of extrachromosomal DNA as a novel oncogenic driver

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Science China Life Sciences 2025年第1期68卷 144-157页

作者： Huanbo Zhu Longtao Huangfu Junbing chen Jiafu Ji Xiaofang xing Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing) Division of Gastrointestinal Cancer Translational Research LaboratoryPeking University Cancer Hospital & Institute Department of Gastrointestinal Cancer Center Peking University Cancer Hospital & Institute Department of Liver Surgery & Transplantation Liver Cancer InstituteZhongshan HospitalFudan University Key Laboratory of Carcinogenesis and Cancer Invasion Ministry of Education State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers Beijing Key Laboratory of Carcinogenesis and Translational ResearchDivision of Gastrointestinal Cancer Translational Research LaboratoryPeking University Cancer Hospital & Institute

Extrachromosomal DNA(ecDNA) is a form of circular DNA mostly found in tumor cells. Unlike the typical chromosomal DNA, ecDNA is circular, self-replicating, and carries complete or partial gene fragments. Although ecDNA occurrence remains a rare event in cancer, recent studies have shown that oncogene amplification on ecDNA is widespread throughout many types of cancer, implying that ecDNA plays a central role in accelerating tumor evolution. ecDNA has also been associated with increased tumor mutation burden, chromosomal instability, and even tumor microenvironment remodeling. ecDNA may be crucial in influencing tumor heterogeneity, drug sensitivity,oncogenic senescence, and tumor immunogenicity, leading to a worsening prognosis for tumor patients. In this way, several clinical trials have been conducted to investigate the importance of ecDNA in clinical treatment. In this review, we summarize the biogenesis, characteristics, and current research methods of ecDNA, discuss the vital role of ecDNA-caused tumor heterogeneity in cancers, and highlight the potential role of ecDNA in cancer therapy.

关键词： extrachromosomal DNA cancer therapy tumor heterogeneity drug resistance tumor evolution