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Current Reversal in a Flashing Correlation Ratchet

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Chinese Physics Letters 1999年第7期16卷 475-477页

作者： ZHAO Tong-jun ZHAN Yong ZHUO Yi-zhong wu xi-zhen Department of Applied Mathematics and Physics Hebei University of Technology Tianjin 300130 China Institute of Atomic Energy Beijing 102413 Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080

A flashing correlation ratchet model is proposed,in which the transport of Brownian particles driven by additive colored noise of Ornstein-Uhlenbeck type in a flashing ratchet is studied by Monte Carlo *** stationary current vs the noise strength and the correlation time is obtained and *** a fixed rate of potential flashing,the novel phenomena of current reversal and reentry *** conditions for the occurrence of these phenomena are *** in fluence of the flipping rate is also *** finding might be relevant to the fact that the protein motors with similar structure can move in opposite directions on the same kind of microtubule.

关键词： directions noise Flash

One-and Two-Neutron Transfer Reactions in ^(11)Be+^(208)Pb and Mechanism of Lowering Fusion Barrier

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Chinese Physics Letters 2000年第11期17卷 789-791页

作者： WANG Ning LI Zhu-xia wu xi-zhen WANG Nan SUN xiu-Quan China Institute of Atomic Energy Beijing 102413 Department of Physics of Northwest University Xian 710069 Nuclear Theory Center of National Laboratory of Heavy Ion Accelarator Lanzhou 730000

We study one-and two-neutron transfer reactions in ^(11)Be+^(208)Pb by using the quantum molecular dynamics *** find that lowering about 1-2 MeV of the potential barrier of ^(208)Pb for fusion is gained when two neutrons separated from ^(11)Be enter into ^(208)*** no significant change of potential barrier is found when only the halo neutron separated from ^(11)Be enters into ^(208)*** dynamical interplay between suppression and enhancement effects on the fusion probability in reaction ^(11)Be+^(208)Pb stemming from the easy separation of halo neutron and the long extending of neutron distribution is discussed.

关键词： separated gained separation

Classical Dynamics of a Nucleon in Heavy Nuclei

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Chinese Physics Letters 1998年第5期15卷 318-320页

作者： GU Jian-zhong ZHAO En-guang ZHUO Yi-zhong wu xi-zhen ZONG Hong-shi Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080 China Institute of Atomic Energy Beijing 102413

Within the framework of the two-center shell model,the classically dynamical behaviour of a nucleon in heavy nuclei is investigated when nuclear shape parameters are changed *** is found that there is a good quantum-classical correspondence of nucleonic regular(chaotic)motion so that Bohigas,Giannoni and Schmit conjecture is confirmed once again.

关键词： behaviour chaotic correspondence

The OH Maser Line Receiving System for the Urumqi 25m Radio Telescope

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Chinese Journal of Astronomy and Astrophysics 2005年第5期5卷 557-562页

作者： Hong-Bo Zhang Jarken Esimbek Jian-Jun Zhou xing-wu zhen xi-zhen Zhang Wen-Jie Yang National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Urumqi Astronomical Observatory National Astronomical Observatories Chinese Academyof Sciences Urumqi 830011 Department of Astronomy Nanjing University 210093 Beijing Institute of Tracking and Telecommunication Technology Beijing 100094

A maser spectral line system is newly implemented on the Urumqi 25m Radio Telescope. The system consists mainly of a cooling receiver and a 4096 channels digital correlation spectrometer. The frequency resolution of the spectrometer at the maximum signal bandwidth of 80MHz is 19.5kHz. After careful calibrations observation at the 1665 MHz OH maser emission was made towards a number of sources, including W49N and W75N. The observed results demonstrate that the digital correlation spectrometer is suitable for astronomical spectral line observations.

关键词： instrumentation: spectrometer - OH maser

Behavior of the Lyapunov Exponent and Phase Transition in Nuclei

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Chinese Physics Letters 2000年第10期17卷 711-713页

作者： WANG Nan wu xi-zhen LI Zhu-xia WANG Ning ZHUO Yi-Zhong SUN xiu-Quan China Institute of Atomic Energy Beijing 102413 Department of Physicsf Northwest University Xi'an 710069 Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080 Nuclear Theory Center of National Laboratory of Heavy Ion Accelerator Lanzhou 730000

Based on the quantum molecular dynamics model,we investigate the dynamical behaviors of the excited nuclear system to simulate the latter stage of heavy ion reactions,which associate with a liquid-gas phase *** try to search a microscopic way to describe the phase transition in *** Lyapunov exponent is employed and examined for our *** find out that the Lyapunov exponent is one of good microscopic quantities to describe the phase transition in hot *** potential and the finite size effect may give a strong influence on the critical ***,the collision term plays a minor role in the process of the liquid-gas phase transition in finite systems.

关键词： temperature. transition. exponent

Effects of Asymmetry of Potential on Stochastic Stokes’ Drift

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Chinese Physics Letters 2001年第4期18卷 488-490页

作者： LI Yu-xiao CAO Tian-Guang wu xi-zhen ZHUO Yi-Zhong China Institute of Atomic Energy P.O.Box 275(18)Beijing 102413 Department of Physics Zhengzhou UniversityZhengzhou 450052 Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080

The directed motion of Brownian particles is generated by a travelling asymmetric *** asymptotic behaviour of probability density of the particles at long time is a solitary *** Brownian particles can do work against an external opposing force with high *** analytical expressions of the solitary wave and the efficiency of the Brownian particles are *** average velocity and the efficiency of the particles depends strongly on the travelling speed and the asymmetry of the potential.

关键词： potential. wave. Brownian

Strengthening effect of prefabrication(10-12)tensile twinning on AZ80+0.4%Ce magnesium alloy and inhibition mechanism of discontinuous precipitation

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Journal of Magnesium and Alloys 2024年第5期12卷 1918-1930页

作者： zhen Wang xi Zhao Zhimin Zhang Yaojin wu Kai Chen xianwei Ren Dengkui Wang Wei Wang School of Mechanical and Electrical Engineering North University of ChinaTaiyuan 030051China Engineering Technology Research Center for Integrated Precision Forming of Shanxi Province North University of ChinaTaiyuan 030051China

This paper provided an effective method to further improve the mechanical properties of the AZ80+0.4%Ce magnesium alloy wheel *** effect of high strength and ductility was obtained with a yield strength of 295.36 MPa,an elongation of 10%,by the combination of pre-deformation(7%deformation)and two-stage aging treatment(120℃/9 h+175℃/24 h).The evolution of the microstructure and properties of the alloy was explored under the coupling conditions of different pre-deformation degrees and multi-stage *** results show that,pre-deformation introduced a large number of(1012)tensile twinning and dislocations,which greatly promoted the probability of continuous precipitates(CPs)*** the contrary,the discontinuous precipitates(DPs)were limited by the vertical and horizontal twin *** a result,the pre-nucleation method of two-stage aging increased the proportion of CPs by 34%-38%.Owing to the DPs was effectively suppressed,the alloy's yield strength has been greatly ***,under multi-stage aging,the twin boundaries induce protruding nucleation to form static recrystallization by hindering the migration of dislocations,and the matrix swallows the twins,then the texture gradually tilts from the two poles to the basal *** an important supplement,the grain refinement and oblique texture promoted the improvement of the yield strength of the component.

关键词： Magnesium alloy Pre-deformed Two-stage aging Tensile twinning Continuous precipitates Texture

Parameter Estimation of Sub-/Super-synchronous Oscillation Based on Interpolated All-phase Fast Fourier Transform with Optimized Window Function

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1031-1041页

作者： Bo Sun xi wu xi Chen Zixiao Zou Qiang Li Bixing Ren School of Electrical Engineering Southeast UniversityNanjingChina State Grid Jiangsu Electric Power Company Limited Research Institute NanjingChina

In recent years,with increasing amounts of renew-able energy sources connecting to power grids,sub-/super-syn-chronous oscillations(SSOs)occurred more *** to the time-variant nature of SsO magnitudes and frequencies,as well as the mutual interferences among SsO modes with close frequencies,the accurate parameter estimation of SsO has be-come a particularly challenging *** solve this issue,this paper proposes an improved spectrum analysis method by im-proving the window function and a spectrum correction method to achieve higher ***,by aiming at the sidelobe characteristics of the window function as evaluation criteria,a combined cosine function is optimized using a genetic algorithm(GA).Furthermore,the obtained window function is self-con-volved to extend its excellent characteristics,which have better performance in reducing mutual interference from other SSO ***,a new form of interpolated all-phase fast Fourier transform(IpApFFT)using the optimized window func-tion is proposed to estimate the parameters of *** meth-od allows for phase-unbiased estimation while maintaining algo-rithmic simplicity and *** performance of the pro-posed method is demonstrated under various conditions,com-pared with other estimation *** results vali-date the effectiveness and superiority of the proposed method.

关键词： Sub-/Super-synchronous oscillation(SSO) window function parameter estimation interpolated all-phase fast Fourier transform(ApFFT)

A state-of-the-art review of the development of self-healing concrete for resilient infrastructure

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Frontiers of Structural and Civil Engineering 2024年第2期18卷 151-169页

作者： Dong LU xi JIANG Yao ZHANG Shaowei ZHANG Guoyang LU zhen LENG Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China Laboratory of Fire Safety School of Safety Engineering and Emergency ManagementShijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Architecture and Civil Engineering City University of Hong KongHong Kong 999077China

The brittleness of cement composites makes cracks almost inevitable,producing a serious limitation on the lifespan,resilience,and safety of concrete *** address this brittleness,self-healing concrete has been developed for regaining its mechanical and durability properties after becoming cracked,thereby promising sustainable development of concrete *** paper provides a comprehensive review of the latest developments in self-healing *** begins by summarizing the methods used to evaluate the self-healing efficiency of ***,it compares strategies for achieving healing *** then discusses the typical approaches for developing self-healing ***,critical insights are proposed to guide future studies on the development of novel self-healing *** review will be useful for researchers and practitioners interested in the field of self-healing concrete and its potential to improve the durability,resilience,and safety of concrete infrastructure.

关键词： resilient infrastructure sustainable concrete self-healing cracks