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On Existence and Uniqueness of Random Impulsive Differential Equations

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Journal of Systems Science & Complexity 2016年第2期29卷 300-314页

作者： zhang Shuorui sun jitao Department of Mathematics Tongji University

This paper studies existence and uniqueness for random impulsive differential *** authors first generalize a random fixed point theorem of Schaefer's *** the authors shall rely on the generalized Schaefer's type random fixed point theorem to discuss the existence of the *** addition,the authors study the existence and uniqueness of random impulsive differential equations by applying random Banach fixed point theorem and obtain some less conservative ***,an example is given to illustrate the effectiveness of the results.

关键词： Existence impulses random differential equations random fixed point uniqueness.

Analysis of epidemic spreading with feedback mechanism in weighted networks

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International Journal of Biomathematics 2015年第1期8卷 81-91页

作者： Jiancheng zhang jitao sun Department of Mathematics Tongji University Shanghai 200092 P. R. China

In this paper, we investigate a new model with a generalized feedback mechanism in weighted networks. Compare to previous models, we consider the initiative response of people and the important impact of nodes with different edges on transmission rate as epidemics prevail. Furthermore, by constructing Lyapunov function, we prove that the disease-free equilibrium E^0 is globally asymptotically stable as the epidemic threshold R^＊〈 1. When R^＊〉 1, we obtain the permanence of epidemic and the local stability of endemic equilibrium E＊. Finally, one can find a good agreement between numerical simulations and our analytical results.

关键词： SIS model weighted network feedback mechanism global analysis

STABILITY OF IMPULSIVE LINEAR HYBRID SYSTEMS WITH TIME DELAY

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Journal of Systems Science & Complexity 2010年第4期23卷 738-747页

作者： Yu zhang·jitao sun Department of Mathematics,Tongji University,Shanghai 200092,China. Department of Mathematics Tongji University Shanghai China

This paper investigates the stability of impulsive linear hybrid systems with time *** a number of delay-independent/delay-dependent stability criteria are obtained by using Lyapunovfunctions or Lyapunov *** examples ... 详细信息

关键词： Impulsive linear hybrid system Lyapunov function Lyapunov functional time delay.

Preparation and application of ZnO doped Pt-CeO2 nanofibers as electrocatalyst for methanol electro-oxidation

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Journal of Rare Earths 2018年第9期36卷 974-980页

作者： yingping Zheng Xin zhang Zhengying zhang Ying Li Yueming sun Yongbing Lou Xiaojun Li Yang Lu College of Chemistry and Chemical Engineering Southeast University Nanjing 211189 China Experimental Testing Center of Hefei Guoxuan High-Tech Power Energy Company Limited Hefei 230011 China

ZnO doped Pt/CeO2 nanocomposites were prepared by electrospinning and reduction *** diffraction（XRD）,transmission electron microscopy（TEM）,energy disperse spectroscopy（EDS） and X-ray photoelectron spectroscopy（XPS） were employed to characterize the *** is observed that ZnO and CeO2 form the hexagonal wurtzite phase and cubic fluorite phase in the nanocomposite,respectively,whilst Pt nanoparticles（NPs） with the number-averaged size of ca.3.1 nm are uniformly distributed on the surface of *** mass fraction of Pt NPs in the nanocomposites is about 10 wt%.The doping of ZnO is effective to promote reactive oxygen species,surface reaction sites and the interaction between Pt and *** catalytic performance of nanocomposites was evaluated by the methanol *** with the catalytic activity,stability of *** a result,it is found that the nanocomposite exhibits much higher activity and stability for methanol oxidation than the undoped Pt/CeO2 catalyst.

关键词： Electrospinning Nanofibers Methanol Electro-oxidation Rare earths

A delayed SEIRS epidemic model with impulsive vaccination and nonlinear incidence rate

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International Journal of Biomathematics 2014年第3期7卷 149-162页

作者： Jiancheng zhang and jitao sun Department of Mathernatics Tongji University Shanghai 200092 P. R. China

In this paper, a delayed SEIRS epidemic model with nonlinear incidence rate and impul- sive vaccination is investigated. In vaccination strategy, we perform impulsive vaccina- tion of newborn infants. Using the discrete dynamic system determined by stroboscopic map, we obtain an infection-free periodic solution and establish conditions, on which the solution is globally attractive. We also conclude that the disease is permanent if the parameters of the model satisfy appropriate conditions. Finally, we illustrate the effec- tiveness of our theorems with numerical simulation. The results obtained in this paper are a good extension of the results obtained in [J. Hou and Z. Teng, Continuous and impulsive vaccination of SEIR epidemic models with saturation incidence rate, Math. Comput, Simulat. 79 （2009） 3038 3054] to the corresponding delayed SEIRS epidemic model with nonlinear incidence rate and impulsive vaccination.

关键词： SEIRS impulsive vaccination delay globally attractive permanence.

Devonian integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

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Science China Earth Sciences 2024年第4期67卷 1036-1070页

作者： Wenkun QIE Kun LIANG Wen GUO Biao GAO Junjun SONG Bo CHEN Pu HUANG Li QIAO Honghe XU jitao CHEN Yucong sun Yichun zhang State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Nanjing 211135China

The Devonian System in the Qinghai-Tibetan Plateau and its surrounding areas is widely distributed,diverse in lithotypes and rich in *** records the crucial processes of continuous subduction and reduction of the Paleo-Asian Ocean in the northern hemisphere and the transformation of the Proto-Tethys Ocean into the Paleo-Tethys Ocean in the southern ***,it is of great significance for explaining the global paleogeographic evolution,tectonic activities and biodiversity changes during this critical *** blocks on both sides of the southern Tienshan suture zone and the Longmu Co-ShuanghuChangning-Menglian suture zone belong to different sedimentary systems and paleobiogeographic realms and regions,showing important tectonic paleogeographic partitioning *** two suture zones represent the main branches of the PaleoAsian Ocean and the Paleo-Tethys Ocean,respectively,and on this basis the Devonian System can be subdivided into three types:the Tienshan type,the Tethys type and the Gondwana *** on recent research progress on the Devonian stratigraphy and paleontology in combining provenance analysis and biotic characteristics in the Qinghai-Tibetan Plateau and surrounding areas,this paper aims to establish the latest integrative stratigraphic framework and conduct paleogeographic reconstruction,providing foundation for exploring the geological evolution and dynamic mechanisms of various terranes and blocks in the northern margin of *** results indicate that the North Qiangtang,South Qiangtang,Simao,Baoshan and Tengchong terranes,as well as the Himalaya Tethys Zone and the South China Block have affinities with the Indian Block,while the Lhasa Terrane has affinities with the Australian Block,and may be located between the South China and Australian *** the Emsian(Early Devonian),the South China Block separated from the northern margin of Gondwana,a process that was accompanied by the opening of the Jinshajiang-Ailaosh

关键词： Devonian Paleo-Tethys Ocean Integrative stratigraphy Biotas Provenance Analysis Paleogeography

Nuclear peripheral chromatin-lamin B1 interaction is required for global integrity of chromatin architecture and dynamics in human cells

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Protein & Cell 2022年第4期13卷 258-280页

作者： Lei Chang Mengfan Li Shipeng Shao Chen Li Shanshan Ai Boxin Xue yingping Hou Yiwen zhang Ruifeng Li Xiaoying Fan Aibin He Cheng Li Yujie sun State Key Laboratory of Membrane Biology School of Life Sciencesand Biomedical Pioneering Innovation Center(BIOPIC)Peking UniversityBeijing 100871China Peking-Tsinghua Center for Life Sciences Academy for Advanced Interdisciplinary StudiesPeking UniversityBeijing 100871China Center for Bioinformatics School of Life SciencesPeking UniversityBeijing 100871China Institute of Molecular Medicine Beijing Key Laboratory of Cardiometabolic Molecular MedicinePeking UniversityBeijing 100871China Center for Statistical Science Peking UniversityBeijing 100871China Bioland Laboratory(Guangzhou Regenerative Medicine and Health Guangdong Laboratory) Guangzhou 510530China

The eukaryotic genome is folded into higher-order conformation accompanied with constrained dynamics for coordinated genome ***,the molecular machinery underlying these hierarchically organized three-dimensional(3D)chromatin architecture and dynamics remains poorly *** by combining imaging and sequencing,we studied the role of lamin B1 in chromatin architecture and *** found that lamin B1 depletion leads to detachment of lamina-associated domains(LADs)from the nuclear periphery accompanied with global chromatin redistribution and ***,the interchromosomal as well as inter-compartment interactions are increased,but the structure of topologically associating domains(TADs)is not *** live-cell genomic loci tracking,we further proved that depletion of lamin B1 leads to increased chromatin dynamics,owing to chromatin decompaction and redistribution toward *** together,our data suggest that lamin B1 and chromatin interactions at the nuclear periphery promote LAD maintenance,chromatin compaction,genomic compartmentalization into chromosome territories and A/B compartments and confine chromatin dynamics,supporting their crucial roles in chromatin higher-order structure and chromatin dynamics.

关键词： lamin B1 3D genome Hi-C chromatin dynamics chromosome territories A/B compartments livecell imaging super-resolution imaging

Persistence in A Three Species Predator-Prey System

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Systems Science and Systems Engineering 1999年第2期9卷 203-208页

作者： sun jitao zhang Yinping(Iust. of Appl. Math., Shanghai Tiedao University, Shanghai 200331, China)

In this paper we consider the persistence of the following three species Lotka-Volterrapredator-prey modelIt’s proved that the Lotka-Volterra model is persistent under appropriate conditions.

关键词： persistence predator-prey system

Large-scale roll-to-roll printed,flexible and stable organic bulk heterojunction photodetector

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npj Flexible Electronics 2018年第1期2卷 42-49页

作者： Sichao Tong Jun Yuan Chujun zhang Chunhua Wang Baoxing Liu Jianqiang Shen Huayan Xia yingping Zou Haipeng Xie Jia sun Si Xiao Jun He Yongli Gao Junliang Yang Hunan Key Laboratory for Super-Microstructure and Ultrafast Process School of Physics and ElectronicsCentral South UniversityChangsha 410083 HunanChina College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083 HunanChina Department of Physics and Astronomy University of RochesterRochesterNY 14627USA

A flexible and stable photodetector shows great potential applications in intelligent wearable devices,health monitoring,and biological *** high-output fabrication of flexible and stable photodetector via the large-scale printing process would accelerate its ***,a high performance,flexible organic bulk heterojunction(BHJ)photodetector with good stability is designed and fabricated via a large-scale roll-to-roll(R2R)micro-gravure printing technique on polyethylene terephthalate(PET)or paper substrate,in which the organic BHJ active layer is structured with[6,6]-phenyl C_(61)butyric acid methyl ester(PCBM)and a donor-acceptor copolymer,i.e.,employing 4,8-bis(2-ethylhexylthiophene)benzo[1,2-b;3,4-b′]dithiophene(BDTT)as the donor unit and 5,8-bis(5-thiophen-2-yl)-6,7-difluoro-2,3-bis(4-ethylhexyloxy-1-mata-luorophenyl)quinoxaline(ffQx)as the acceptor unit(PBDTT-ffQx).The PBDTT-ffQx/PCBM BHJ photodetector shows a broad photoresponse in ultraviolet and visible light,a high detectivity(D^(*))value up to 6.19×10^(11)Jones,and an excellent Iphoto/Idark as high as 5.6×10^(2).It exhibits excellent flexibility and *** performance parameters could maintain over 80%of original values after bending 10,000 cycles or exposing in ambient condition(humidity~50%,temperature~30℃)for 50 days without any *** importantly,the R2R micro-gravure printed PBDTT-ffQx/PCBM BHJ active layer is great homogeneous,and the responsivity(R)values of photodetector arrays show a very narrow *** research results show that a high-performance PBDTT-ffQx/PCBM BHJ photodetector with well reliability and reproducibility can be fabricated via the R2R micro-gravure printing technique,which provides an available strategy for fabricating large-area and flexible electronic and optoelectronic devices.

关键词： printing heterojunction donor