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Effect of the Vibrational Modes on the Ag-Cu Phase Diagram

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Chinese Physics Letters 2000年第7期17卷 522-524页

作者： DUAN Su-Qing ZHAO Xian-Geng LIU Shao-Jun ma ben-kun Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100088 Department of Physics Beijing Normal UniversityBeijing 100875

We calculated the vibrational free energies of the selected ordered compounds in the Ag-Cu system by using two kinds of methods: (1) calculating the phonon dispersion and density of states and the consequently vibrational free energies by using the method of ab initio inverted interatomic potentials and dynamic matrix;(2) the vibrational free energies determined by a Debye-Griineisen approximation. The Ag-Cu phase diagram is calculated by the cluster variation method. The results show that the solubility at Ag-rich end of the calculated phase diagram considering vibrational modes by using the first method is in better agreement with the experimental.

关键词： method vibrational diagram

Spectra of Hydrogenic Donor States in Quantum-Dot Quantum Well Structures

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Chinese Physics Letters 1999年第9期16卷 680-682页

作者： UO Ying XIE Hong-jing ma ben-kun LI Jia-qiang ZHU Jia-lin Department of Physics Beijing Normal UniversityBeijing 100875 Department of Physics Tsinghua UniversityBeijing 100084 Center of Theoretical Physics Chinese Center of Advanced Science and Technology(World Laboratory)P.O.Box 8730Beijing 100080

The series expansion approach has been employed to calculate the exact energy spectra of hydrogenic donor states in a quantum-dot quantum well(QDQW). The result shows that the hydrogenic donor energy levels are very different from those in a quantum dot. In a QDQW, the donor energy levels depend on not only the radius of core and the barrier, but also the numbers of small wells. When there exist two small wells outside the core, the “band gap”exists between donor levels, and its width depends on the depth of the small wells.

关键词： donor quantum hydrogenic

非局域Lai-Das Sarma-Villain方程动力学标度性质的研究

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物理学报 2001年第5期50卷 851-855页

作者：唐刚马本 北京师范大学物理系和理论物理研究所

使用动力学重整化群和直接标度分析的方法研究了非局域Lai DasSarma Villain方程的动力学标度性质 .动力学重整化群分析表明非局域非线性项的存在能够导致新的固定点和连续变化的动力学标度指数的产生 .使用直接标度分析方法则分别得到... 详细信息

使用动力学重整化群和直接标度分析的方法研究了非局域Lai DasSarma Villain方程的动力学标度性质 .动力学重整化群分析表明非局域非线性项的存在能够导致新的固定点和连续变化的动力学标度指数的产生 .使用直接标度分析方法则分别得到了在弱耦合和强耦合区内的标度指数值 .在弱耦合区域内得到的标度指数与动力学重整化方法得到的标度指数值能很好地吻合 .

关键词：表面生长动力学重整化群分析直接标度分析 Lai-Das Sarma-Villain方程动力学标度性质标度指数表面界面动力学

Effect of Electric Field on the Electron-Surface Optical Phonon Scattering Rates in Quantum Wires

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Chinese Physics Letters 1996年第4期13卷 297-300页

作者： CHANG Kai WANG Ruo-zhen ma ben-kun Department of Physics Beijing Normal UniversityBeijing 100875

By using the variational method and the dielectric continuum model,we investigate the effect of electric Held on the intrasubband scattering rates of electron-surface optical *** results show that the scattering rates tend to increase with the electric field *** scattering rates become significant for wide quantum well wire and sufficiently high fields.

关键词： strength. Electron variational

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双量子点分子的电子结构

物理学报 2001年第2期50卷 278-286页

作者：王立民罗莹马本堃北京师范大学物理系和理论物理研究所

采用推广的LCAO方法和有限元方法计算了两个相同量子点组成的双量子点分子的电子结构 ,结果表明这种人造分子间的相互作用随两个量子点中心之间距离的变化可实现由共价键向离子键的转变 .对于两个不同的量子点组成的双量子点分子 ,利用... 详细信息

采用推广的LCAO方法和有限元方法计算了两个相同量子点组成的双量子点分子的电子结构 ,结果表明这种人造分子间的相互作用随两个量子点中心之间距离的变化可实现由共价键向离子键的转变 .对于两个不同的量子点组成的双量子点分子 ,利用有限元方法计算了两个量子点中心之间距离、量子点受限势高度以及量子点半径对这种人造分子的电子结构的影响 ,定性地说明了Oosterkamp等人的实验现象 .

关键词：双量子点分子电子结构共价键离子键

二维Bloch电子在电场和磁场作用下输运的突变现象及非线性理论分析

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物理学报 1997年第4期46卷 762-766页

作者：田强朱轶男北京师范大学物理系

磁场作用下二维Ｂｌｏｃｈ电子，在非极低温情况下，电子Ｂｌｏｃｈ能带的磁致裂隙对电子运动的影响将不重要，这时在准经典近似下分析霍耳漂移速率．通过数值求解，得到不同磁感应强度下波矢空间的稳定唯一周期解或稳定焦点不动解，并... 详细信息

磁场作用下二维Ｂｌｏｃｈ电子，在非极低温情况下，电子Ｂｌｏｃｈ能带的磁致裂隙对电子运动的影响将不重要，这时在准经典近似下分析霍耳漂移速率．通过数值求解，得到不同磁感应强度下波矢空间的稳定唯一周期解或稳定焦点不动解，并通过大量数值计算找出了参数空间中周期解与不动解的参数划分；进一步给出了霍耳漂移速率随磁感应强度变化过程中的突变现象．

关键词： Bloch电子电场磁场输运突变非线性

Effect of Reclamation on the Groundwater-Lake Water Interaction in Chen Lake

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Journal of Earth Science 2024年第3期35卷 1083-1086页

作者： kun Lei Teng ma Liuzhu Chen Zhenxing Li Yu Chen School of Environmental Studies State Key Laboratory of Biogeology and Environmental GeologyChina University of GeosciencesWuhan 430078China

0 INTRODUCTION To relieve the short supply of suitable land for residing,cultivating,and commerce,it is accepted to reclaim land from lakes,river estuaries,and coastal regions in many countries(mancini et al.,2020).The large-scale reclamation activities have an irreversible effect on the mico-geomorphology and hydrodynamic system of seasonally flooded areas(Zhang et al.,2019;Yu et al.,2018).For example,coastal regions reclaimed extended the groundwater flow paths,as well as created groundwater level rise,resulting in water-logging in the reclaimed area(Hu et al.,2008).Similar changes in groundwater flow systems may alter groundwater-lake water interactions,and it can ultimately affect the water cycle in the lake ***,such detailed studies are presently *** addition,natural exchanges between the lake and groundwater systems can be strongly affected by physical hydrological processes(Javadzadeh et al.,2020),chemical properties(Kamtchueng et al.,2015),and bioto behavior(Hancock et al.,2005).

关键词： groundwater coastal logging

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半导体量子点的形状对受限激子的影响

物理学报 1999年第7期48卷 1320-1326页

作者：罗莹王若桢北京师范大学物理系

在有效质量近似范围内，采用有限深势阱模型，考虑介电受限、计入表面极化效应的情况下，研究了球形、立方形半导体量子点的形状对受限激子的影响．

关键词：半导体量子点形状有限深势阱受限激子

Coordinated optimization of signal timing for intersections with dynamic shared through-and right-turn lanes

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Journal of Intelligent and Connected Vehicles

Journal of Intelligent and Connected Vehicles 2024年第3期7卷 219-228页

作者： Zhe Zheng Jian Yuan kun An Nan Zheng Wanjing ma The Key Laboratory of Road and Traffic Engineering Ministry of EducationTongji UniversityShanghai 201804China Department of Civil Engineering Monash UniversityMelbourne VIC 3800Australia

Through and right-turn shared lanes are widely designed to increase the capacity of through traffic,but they can also cause delays for right-turn *** study presents a dynamic control method for a shared lane that prioritizes right-turn vehicles at the beginning of the cycle and subsequently allows through traffic to queue in the shared lane for saturated *** traffic wave model is employed to reveal the dynamics of the traffic flow under this control and to derive the relationships among major traffic *** by the major relationship,a linear programming approach to minimize the total queue length is developed to determine the proper values of control parameters,including the shared area length,subordinate signal time lag,and shared or exclusive duration.A sensitivity analysis of the control parameters for different arrival rates and flow ratios is *** are conducted among the dynamic shared lane,the fixed exclusive lane,and the fixed shared *** results show that the dynamic control method results in a lower delay for both through and total traffic.

关键词： traffic control dynamic lane right-turn traffic optimization model