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Spheres of Urban Influence and Factors in Beijing-tianjin-Hebei Metropolitan Region Based on Viewpoint of Administrative Division Adjustment

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Chinese Geographical Science 2017年第5期27卷 709-721页

作者： ZHU Jianhua CHEN xi CHEN tian School of Geographic Sciences Northeast Normal UniversityChangchun 130024China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Northeast Asian Studies College Jilin UniversityChangchun 130012China

The coordinated development of Beijing, tianjin and Hebei has been elevated as China's important strategy. And, the priority in considering how to bring the maximum effect of their coordinated development into play is to delineate the spheres of urban influence with regard to the cities in the Beijing-tianjin-Hebei Metropolitan Region. By building an evaluation index system of urban comprehensive strength, this paper applies the principal component analysis method to determine centrality strength of the cities, and the breakpoint theory and weighted Voronoi diagram to identify the spheres of urban influence in all central cities of the region. Results show that 13 central cities within the region greatly differ in strength, which can be classified into four tiers and that the spheres of urban influence do not have a high goodness of fit with administrative jurisdiction scope. Cities like Beijing, tianjin, Shijiazhuang and Handan have larger spheres of urban, spheres of urban influence in Tangshan and Qinhuangdao are basically consistent with their administrative jurisdiction scopes, and seven cities including Langfang and Baoding have smaller spheres of urban influence. So according to these cities' comprehensive strength and spheres of influence, the region can be divided into five plates: Beijing, tianjin, Shijiazhuang, Tangshan and Handan. The major influence factors for inconsistency between spheres of urban influence and spheres of jurisdiction include difference in urban administrative ranking, small number of central cities with weak strength, discrepancy in the number of counties under jurisdiction, unreasonable spheres of jurisdiction and diversity in topographical conditions. In order to solve the imbalance in the spheres of urban influence and those of jurisdiction and better facilitate the coordinated development of the region, it is advised to adjust administrative areas so as to obtain more optimized urban spatial layout and more reasonable urban scale

关键词： spheres of urban influence urban comprehensive strength adjustment of administrative divisions weighted Voronoi diagram Beijing-tianjin-Hebei Metropolitan Region

A Longitudinal Study of the Effects of Family Background Factors on Mathematics Achievements Using Quantile Regression

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Acta Mathematicae Applicatae Sinica 2008年第1期24卷 85-98页

作者： xi-zhi Wu Mao-zai tian Center for Applied Statistics School of Statistics Renmin University of China Beijing 100872 China School of Statistics Renmin University of China Beijing 100872 China

Quantile regression is gradually emerging as a powerful tool for estimating models of conditional quantile functions, and therefore research in this area has vastly increased in the past two decades. This paper, with the quantile regression technique, is the first comprehensive longitudinal study on mathematics participation data collected in Alberta, Canada. The major advantage of longitudinal study is its capability to separate the so-called cohort and age effects in the context of population studies. One aim of this paper is to study whether the family background factors alter performance on the mathematical achievement of the strongest students in the same way as that of weaker students based on the large longitudinal sample of 2000, 2001 and 2002 mathematics participation longitudinal data set. The interesting findings suggest that there may be differential family background factor effects at different points in the mathematical achievement conditional distribution.

关键词： Mathematical achievement family background factors quantile regression confidence intervals,longitudinal study

Exact Entanglement Dynamics in Three Interacting Qubits

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Chinese Physics Letters 2018年第11期35卷 11-15页

作者： wen-Bin He xi-wen Guan State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 University of Chinese Academy of Sciences Beijing 100049 Center for Cold Atom Physics Chinese Academy of Sciences Wuhan 430071 Department of Theoretical Physics Research School of Physics and Engineering Australian National University Canberra ACT 0200 Australia

Motivated by recent experimental studies on coherent dynamics transfer in three interacting atoms or electron spins [Phys. Rev. Lett 114（2015） 113002, Phys. Rev. Lett 120（2018） 243604], here we study entanglement entropy transfer in three interacting qubits. We analytically calculate time evolutions of wave function, density matrix and entanglement of the system. We find that initially entangled two qubits may alternatively transfer their entanglement entropy to other two qubit pairs. Thus dynamical evolution of three interacting qubits may produce a genuine three-partite entangled state through entanglement entropy transfers. In particular, different pairwise interactions of the three qubits endow symmetric and asymmetric evolutions of the entanglement transfer,characterized by the quantum mutual information and concurrence. Finally, we discuss an experimental proposal of three Rydberg atoms for testing the entanglement dynamics transfer of this kind.

关键词： Exact Entanglement Dynamics in Three Interacting Qubits

Parallel-batch scheduling with deterioration and rejection on a single machine

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Applied Mathematics(A Journal of Chinese Universities) 2020年第2期35卷 141-156页

作者： LI Da-wei LU xi-wen School of Science East China University of Science and TechnologyShanghai 200237China.

The single machine parallel-batch scheduling with deteriorating jobs and rejection is considered in this paper.A job is either rejected,in which a rejection penalty should be paid,or accepted and processed on the *** job’s processing time is an increasing linear function of its starting *** machine can process any number of jobs simultaneously as a *** processing time of a batch is equal to the largest processing time of the jobs in the *** objectives are to minimize the makespan and the total weighted completion time,respectively,under the condition that the total rejection penalty cannot exceed a given upper bound *** show that both problems are NP-complete and present dynamic programming algorithms and fully polynomial time approximation schemes(FPTASs)for the considered problems.

关键词： parallel-batch scheduling rejection deterioration FPTAS NP-complete

Recent Advances in High‑Efficiency Electrocatalytic Water Splitting Systems

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Electrochemical Energy Reviews 2023年第1期6卷 1-38页

作者： xian‑Wei Lv wen‑wen tian Zhong‑Yong Yuan Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) School of Materials Science and EngineeringNankai UniversityTianjin 300350China

Electrocatalytic water splitting driven by renewable energy input to produce clean hydrogen(H_(2))has been widely considered a prospective approach for a future hydrogen-based ***,the development of industrial alkaline water electrolyzers is hindered due to their unfavorable thermodynamics with high overpotential for delivering the whole process,caused by sluggish kinetics involving four-electron *** exploration of water electrolysis with low energy consumption and high efficiency is urgently required to meet the ever-growing energy storage and portfolio *** review emphasizes the strategies proposed thus far to pursue high-efficiency water electrolysis systems,including from the aspects of electro-catalysts(from monofunctional to bifunctional),electrode engineering(from powdery to self-supported),energy sources(from nonrenewable to renewable),electrolytes(from pure to hybrid),and cell configurations(from integrated to decoupled).Critical appraisals of the pivotal electrochemistry are highlighted to address the challenges in elevating the overall efficiency of water ***,valuable insights for the future development directions and bottlenecks of advanced,sustainable,and high-efficiency water splitting systems are outlined.

关键词： Electrocatalytic water splitting Hydrogen-based society Electrode engineering Cell configurations Challenges and perspectives

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辽朝详稳渊源新论

古代文明（中英文） 2025年第1期19卷 117-127,M0006,M0007页

作者：田富吉林大学历史文化学院吉林长春130012

以往学界多认为辽朝详稳源于突厥语“sangun”,为将军之意。本文通过考证详稳与相温、相公、将军等概念的异同,认为辽朝详稳一词源自汉语“相”,“稳”是指契丹语语法中修饰“详”字的附加成分。辽朝详稳官职来源于突厥、回鹘、吐蕃等... 详细信息

以往学界多认为辽朝详稳源于突厥语“sangun”,为将军之意。本文通过考证详稳与相温、相公、将军等概念的异同,认为辽朝详稳一词源自汉语“相”,“稳”是指契丹语语法中修饰“详”字的附加成分。辽朝详稳官职来源于突厥、回鹘、吐蕃等边疆民族之“相”制,又在“会同改制”过程中脱离其原义,遂成为一种特殊的部族官职。

关键词：辽朝详稳相相温国相

Single crystal growth and electrochemical studies of garnet-type fast Li-ion conductors

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Tungsten 2022年第4期4卷 263-268页

作者： Yi-tian Wang xi Chen Department of Electrical and Computer Engineering University of CaliforniaRiversideCA92521USA

All-solid-state batteries have attracted much attention due to their improved safety and higher energy density as compared to the conventional *** to the excellent chemical stability against lithium metal and relatively high ionic conductivity at room-temperature,garnet-type fast lithium ion conductors with three-dimensional lithium ion transport channels are promising solid electrolytes for all-solid-state *** order to better understand the intrinsic lithium-ion transport mechanisms and prevent lithium dendrite formation,it is desired to investigate single-crystal solid *** this perspective,we review several methods reported to grow single crystals of garnet-type *** and cons of different growth methods are ***,we introduce some case studies on electrochemical properties of garnet-type single *** addition,we provide some perspectives about potential research directions of single-crystal solid electrolytes for all-solid-state batteries.

关键词： Solid electrolyte Single crystal Garnet-type lithium-ion conductor All-solid-state battery Crystal growth

Phase-field model of precipitation processes with coherency loss

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npj Computational Materials 2021年第1期7卷 338-348页

作者： tian-Le Cheng You-Hai wen National Energy Technology Laboratory AlbanyORUSA Leidos Research Support Team AlbanyORUSA

A phase-field model is proposed to simulate coherency loss coupled with microstructure evolution.A special field variable is employed to describe the degree of coherency loss of each particle and its evolution is governed by a Ginzburg-Landau type kinetic *** the sake of computational efficiency,a flood-fill algorithm is introduced that can drastically reduce the required number of field variables,which allows the model to efficiently simulate a large number of particles sufficient for characterizing their statistical features during Ostwald *** model can incorporate size dependence of coherency loss,metastability of coherent particles,and effectively incorporate the underlying mechanisms of coherency loss by introducing a so-called differential energy *** model is applied to simulate coarsening of Al3Sc precipitates in aluminum alloy and comprehensively compared with *** results clearly show how the particle size distribution is changed during coherency loss and affects the coarsening rate.

关键词： coherency alloy microstructure

Microstructure and mechanical properties of magnesium–lithium alloy prepared by friction stir processing

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Rare Metals 2021年第9期40卷 2552-2559页

作者： Qian-Ying Che Kuai-She Wang wen Wang Li-Ying Huang tian-Qi Li xiao-Peng xi Pai Peng Ke Qiao School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China National and Local Joint Engineering Research Center for Functional Materials Processing Xi’an 710055China School of Materials Engineering Xi’an Aeronautical UniversityXi’an 710077China

In this study, the fine-grained Mg–Li alloy was prepared by friction stir processing(FSP). The microstructure and mechanical properties of the frictionstir-processed(FSPed) Mg–Li alloy were investigated. The result showed that FSP resulted in the grain refinement, and the average grain size of the b-Li phase was about 7.5 *** the a-Mg and b-Li phases, a small amount of Li_(3)Mg_(7), Li_(2)MgAl and AlLi phases were obtained. Compared with the base metal(BM), the weakening of the crystallographic texture occurred in the FSPed material,and the c-axis of the a-phase and the crystallographic orientation of the b-phase were tilted about 45°with respect to the transverse direction(TD). The average microhardness(HV 67.8) of the stir zone was higher than that of the BM(HV 61.5). The yield strength(YS) and the ultimate tensile strength(UTS) of the FSPed material were higher than those of the BM, while the elongation slightly reduced. Grain refinement had more significant effect on strength improvement compared with the texture variation for the FSPed material. The fracture surfaces of the BM and FSPed materials showed dimple characteristics.

关键词： Magnesium-lithium alloy Friction stir processing Grain size Grain orientation Mechanical property