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Truncation and aliasing errors for Whittaker-Kotelnikov-Shannon sampling expansion

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Applied Mathematics(A Journal of Chinese Universities) 2012年第4期27卷 412-418页

作者： YE Pei-xin SONG zhan.jie School of Mathematics and LPMC Nankai UniversityTianjin 300071China Department of Mathematics School of ScienceTianjin UniversityTianjin 300072China

Let B^pΩ, 1 ≤ p 〈 ∞, be the space of all bounded functions from Lp（R） which can be extended to entire functions of exponential type Ω. The uniform error bounds for truncated Whittaker-Kotelnikov-Shannon series based on local sampling are derived for functions f ∈ B^pΩ without decay assumption at infinity. Then the optimal bounds of the aliasing error and truncation error of Whittaker-Kotelnikov-Shannon expansion for non-bandlimited functions from Sobolev classes L/（Wp（R）） are determined up to a logarithmic factor.

关键词： Whittaker-Kotelnikov-Shannon theorem localized sampling truncation error aliasing error,Sobolev class.

Transcriptional activation of Nlp by estrogen-ERa in breast cancer

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Science Bulletin 2017年第21期62卷 1445-1454页

作者： jia li jie chen liyan xue qimin zhan State Key Laboratory of Molecular Oncology Cancer Institute and HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBejing 100021China Laboratory of Molecular Oncology Peking University Cancer HospitalBeijing 100142.China Department of Pathology Cancer Institute and HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100021China

Estrogen Receptor-a （ERa） is the key transcription factor that regulates cell proliferation and homeosta- sis. In this pathway, estrogen plays an important role in genomic instability and cell cycle regulation pro- cesses and the mechanisms of its action are multifaceted. In this study, we showed that estrogen regulates genomic instability through promoting the expression of Nip, a BRCAl-associated centrosomal protein which is involved in microtubule nucleation, spindle formation, chromosomal missegregation and abnormal cytokinesis. We demonstrated that the expression of Nip is strongly associated with ERa and FOXAI level in clinical breast cancer samples with poor clinical outcomes to breast cancer patients. Addition of estrogen in the ER-positive breast cancer cells resulted in elevation of NLP mRNA. Significantly, we identified that estrogen-ERa is capable of regulating Nlp expression through specifically binding ERa to the proximal region and the Estrogen Responsive Elements （ERE） enhancer in the distal region of NLP gene. Reporter assays demonstrated that estrogen directly activated Nlp promoter. ChIP assay results showed that E2-ERa directly bound to the EREs of Nip. Therefore, overexpression of Nip in breast cancer exhibits a hormone-dependent pattern, and estrogen participates in the regulation of genome instability and cell cycle in breast cancer cells partially through transcriptional activation of NLP gene. Overexpression of Nlp enhances the malignant progression of ERa-positive breast cancer cells in vitro, whereas knockdown of Nip suppresses this biological effects in ERa-positive breast cancer ceils. ERa/NIp axis may serve as a promising target against breast cancer.

关键词： NipBreast cancerEstrogen receptor-or (ERct)1713-Estradiol (E2)Estrogen responsive elements (EREs)Transcriptional activation

Power Extraction Performance of a Semi-activated Flapping Foil in Gusty Flow

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Journal of Bionic Engineering 2017年第1期14卷 99-110页

作者： Jiapu zhan.Bing Xu jie Wu Jing Wu Department of A erodynamics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Jiangsu Key Laboratory of Hi- Tech Research for Wind Turbine Design Nanjing 210016 China

A numerical investigation on the power extraction performance of a semi-activated flapping foil in gusty flow is conducted by using the commercial software FLUENT. The foil is forced to pitch around the axis at one-third chord and heave in the vertical direction due to the period lift force. Different from previous work with uniform flow, an unsteady flow with cosinusoidal velocity profile is considered in this work. At a Reynolds number of 1100, the influences of the mechanical parameters （spring constant and damping coefficient）, the amplitude and frequency of the pitching motion, the amplitude of the gust fluctuation and the phase difference between the pitching motion and the gusty flow on the power extraction performance are systematically investigated. Compared with the case of uniform flow, the capability energy harvesting of the system is enhanced by the introduction of the gusty flow. For a given pitching amplitude and frequency, the power extraction efficiency increases with the gust fluctuation amplitude. Moreover, with an optimal phase difference between pitch and gust （φ = 180°）, the efficiency can be further enhanced due to the generation of high lift force.

关键词： semi-activated flapping foil gusty flow power extraction performance

Enhanced memristor performance via coupling effect of oxygen vacancy and ferroelectric polarization

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Journal of Materials Science & Technology 2024年第4期171卷 139-146页

作者： Zhi Yun Yue Zhi Dong zhan. zhan.jie Wang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China

As a new type of nonvolatile memory,the resistive memristor has broad application prospects in in-formation storage and neural computing based on its excellent resistive switching(RS)*** present,it is still a great challenge to improve both ferroelectric polarization and leakage current to achieve a high RS on/offratio of ferroelectric ***,epitaxial Pb(Zr_(0.40)Ti_(0.60))O_(3)(PZT)thin films with low content Ca doping were deposited on the Nb:SrTiO_(3)substrate to prepare PCZT/NSTO het-erostructures and their RS behaviors were *** research findings show that compared with pure PZT film,the ferroelectric polarization of 1-mol%-Ca-doped PZT film is slightly improved,while the leak-age current is increased by three orders of ***,the RS on/offratio reaches 2.5×10^(5),about three orders of magnitude higher than pure PZT *** theoretical analysis reveals that the RS behavior of PCZT/NSTO heterostructures is controlled by the PCZT/NSTO interfacial barrier and the space charge-limited current *** results demonstrate that the ferroelectricity and electricity of ferroelectric thin films can be improved simultaneously by doping low-content Ca ions to increase the RS performance,which provides a good reference for the development of high-performance ferroelectric memristor devices.

关键词： Ferroelectric memristor Ca-doped PZT Ferroelectric polarization Oxygen vacancies Resistive switching

General Model of Temperature-dependent Modulus and Yield Strength of Thermoplastic Polymers

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Chinese Journal of Polymer Science 2020年第4期38卷 382-393,I0007页

作者： Ping-Yuan Huang zhan.Sheng Guo jie-Min Feng Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai200072China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai 200072China

A general model was developed to predict the temperature-dependent modulus and yield strength of different thermoplastic *** model,which depends on only two parameters with clear and specific physical meanings,can describe the temperaturedependent modulus and yield strength of thermoplastic polymers over the full glass transition *** temperature-dependent modulus and yield strength of three thermoplastic polymers were measured by uniaxial tension tests over a temperature range of 243-383 *** predictions showed excellent agreement with the experimental *** analysis of model input parameters showed negligible effect on the present general *** universality of the present general model was further validated,showing excellent agreement with published experimental data on other thermoplastic polymers and their composites.

关键词： Thermoplastics Modulus Yield strength Modeling Glass transition

Research on theoretical and numerical methods of single bubble oscillation

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Journal of Hydrodynamics 2021年第4期33卷 872-877页

作者： jie-min zhan.Yue-han Chen Yu-tian Li Department of Applied Mechanics and Engineering Sun Yat-sen UniversityGuangzhou510275China

A comparison of theoretical investigation and numerical simulation of a single bubble oscillation is carried out in this *** theoretical research is based on solving Rayleigh-Plesset(R-P)equation and Keller-Miksis(K-M)equation using Runge-Kutta *** numerical method focuses on the two discrete methods in the volume of fluid(VOF)method,geometric reconstruction(GR)and modified high resolution interface capturing(MHRIC).The results show that the interface captured by MHRIC in the collapse stage is more stable,and the evolution of bubble radius agrees better with the theoretical *** R-P equation and K-M equation,which omit the effect of the energy equation,have limitations when the bubble collapses under ultra-high pressure.

关键词： Cavitation bubble dynamics volume of fluid method geometric reconstruction(GR)

NUMERICAL SOLUTION OF THE NAVIER-STOKES EQUATIONS FOR 3-D REGION USING BODY-FITTED COORDINATE SYSTEM

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Journal of Hydrodynamics 1991年第3期3卷 105-109页

作者： jie-min, zhan.Di-ming, zhan. Shongskan Univ Guangzhou China

A three-dimensional method is presented for the three dimensional Navier-Stokes equations using body-fitted coordinate system. For the convenience of generating the coordinate system, we give some slip-coordinate boundary conditions. Numerical results for driven flow in a polar cavity show excellent agreement with the experimental study given by L. Fuchs and N. Tillmark.

关键词： Computers Applications Fluid Mechanics Mathematical Models

Stability analysis in an AVQ model of Internet congestion control algorithm

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The Journal of China Universities of Posts and Telecommunications 2012年第4期19卷 22-28页

作者： zhan.Zhen-qiu ZHU jie XU Di Department of Electronic Engineering Shanghai Jiao Tong UniversityShanghai 200240China

This paper focuses on the local stability of a classical congestion control model in the Intemet, namely adaptive virtual queue （AVQ） algorithm with feedback delay. Firstly, necessary and sufficient stability conditions in terms of key tuning parameters are given, which can provide exact guidelines for setting system parameters. Furthermore, by computing the rightmost characteristic root, the optimal parameter configuration for AVQ is derived, which can guarantee superior stability performance. Finally, some simulation examples are given to illustrate the correctness of the theoretical analysis.

关键词： congestion control AVQ stability time delay system

National Spirit Mobilization in Response to Pandemics

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学术界 2020年第4期 193-202页

作者： zhan.Xiaomei jie Xijie School of MarxismSun Yat-sen University Guangzhou Guangdong 510275 School of Communication and DesignSun Yat-sen University Guangzhou Guangdon g510006

The cohesion of social“emotion–norm–goal”in response to major pandemics means the intention coordination of the involved group attitude,the value regulation of joint participations and the system optimization of power *** cohesive mobilization includes the core role and key variables of the government’s initiative and public response,with social rectification functions of centralized leadership,social coordination and public participation as *** mobilization of national spirit in the process of cohesion emphasizes the formation of guidance,persuasion and influence of internal driving force based on value concept,which are mainly represented in the form of emotional mobilization,normative mobilization and goal ***“emotional paradigm”of national spirit mobilization that enters the practical level focuses on the“heart-warming”function of emotional strategy rituals;“normative paradigm”shows the function of“heart-winning”in the sense of norms and shapes interpretation scheme as well as social regulations of social cohesion value reproduction;“goal paradigm”reflects the“confidence strengthening”function led by collective actions,and conducts the goal transmission and framework construction of“idea+action”.

关键词： major pandemic response social cohesion national spirit mobilization