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Chinese Geographical Science 2008年第3期18卷 224-234页

作者： WANG Kaiyong GAO Xiaolu chen tian Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China

With rapid urbanization process, the pace of urban sprawl has been quickened and most metropolises have ex-perienced expansions in leaps and bounds in suburbanization, which has greatly changed the urban and rural spatial struc-ture of the metropolis fringe area. In this paper, Shuangliu County is taken as a case, since it is a typical fringe area of chengdu Metropolis. Based on Landsat TM images of chengdu City and Shuangliu County obtained in 1985, 2000 and 2004, characteristics of urban and rural spatial structure in Shuangliu County were analyzed, such as core-periphery spa-tial structure and some obvious integration trends. Then the influencing factors for the formation of urban and rural spatial structure were identified, including some natural, social, economic and political factors. According to the discussion of this paper, Shuangliu County is undergoing a key transition and reform period. Its formation of urban and rural spatial structure was affected not only by such common factors as the location, natural background, industrial transition, migra-tion, etc., but also by some unique factors such as city planning and policy guidance, which played an important role in accelerating its uneven spatial structure. The understanding of the role of the influencing factors would be useful for car-rying out spatial management and development planning of metropolis fringe area.

关键词： urbanization urban and rural spatial structure metropolis fi'inge area China

Utilization Pattern of Olympic Parks and Its Application in Beijing

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Chinese Geographical Science 2010年第5期20卷 414-422页

作者： HE Yan chen tian ZHANG Meng Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China Faculty of International Tourism Macao University of Science and Technology Macao 999078 China

With great promotion of mega-events in both quantities and qualities in China, the research of Mega-events has been increased. As a global hallmark event, the Olympics, with their enormous scale, universal attraction for the media and tremendous political significance, have increasingly drawn attention from the researchers. It is obvious that Beijing has been greatly impacted by the 2008 Olympic Games as the host. The event aroused close attention of researchers, especially the problem how the Olympic stadiums and facilities can be utilized after Olympic Games. The paper employed 3 methods to conduct a survey, that is, sending questionnaires to tourists, in- terviewing with government officers, and collecting information about former Olympic Parks from Intemet and lit- eratures. The utilization of former Olympic Parks after Games was summarized and some experiences were refined. Besides, 3 main bodies including government, business operators and visitors which formed basic driving forces to influence the park＇s use were analyzed. At the same time, the paper believes that 3 topics affect the park＇s utilization involving ＇prepare to use＇, ~how to use it＇ and ~how to manage it＇, and Beijing Olympic Park can also follow that thinking and reference in the ft^her practices. Based on it, suggestions are given that Beijing Olympic Park can be planned spatially from 3 layers, the point, line and area, based on their function and infrastructure in the Games, and the area would be shaped as a new urban center with multi-functions while Mega-events and sport events are still the main content of the park.

关键词： sustainable utilization Olympic Park (Olympic Green) Beijing Olympic Park Beijing

The distribution of the large partial quotients in continued fraction expansions

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Science China Mathematics 2023年第5期66卷 935-956页

作者： Bo Tan chen tian Baowei Wang School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074China

The existence of large partial quotients destroys many limit theorems in the metric theory of continued *** achieve some variant forms of limit theorems,a common approach mostly used in practice is to discard the largest partial quotient,while this approach works in obtaining limit theorems only when there cannot exist two terms of large partial quotients in a metric *** by this,we are led to consider the metric theory of points with at least two large partial *** precisely,denoting by[a1(x),a2(x),...]the continued fraction expansion of x∈[0,1)and lettingψ:N→R+be a positive function tending to in nity as n→∞,we present a complete characterization on the metric properties of the set,i.e.,E(ψ)={x∈[0,1):∃16 k̸=ℓ6 n,ak(x)>ψ(n),aℓ(x)>ψ(n)for in nitely many n∈N}in the sense of the Lebesgue measure(the Borel-Bernstein type result)and the Hausdor dimension(the Jarnik type result).The main result implies that any nite deletion from a1(x)+……+an(x)cannot result in a law of large numbers.

关键词： continued fraction Hausdor dimension Borel-Bernstein theorem

Fuzzy cost-profit tradeoff model for locating a vehicle inspection station considering regional constraints

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第12期15卷 1138-1146页

作者： Guangdong tian Hua KE Xiaowei chen Transportation College Northeast Forestry University School of Economics and Management Tongji University Department of Risk Management and Insurance Nankai University

Facility location allocation(FLA) is one of the important issues in the logistics and transportation fields. In practice, since customer demands, allocations, and even locations of customers and facilities are usually changing, the FLA problem features uncertainty. To account for this uncertainty, some researchers have addressed the fuzzy profit and cost issues of FLA. However, a decision-maker needs to reach a specific profit, minimizing the cost to target customers. To handle this issue it is essential to propose an effective fuzzy cost-profit tradeoff approach of FLA. Moreover, some regional constraints can greatly influence FLA. By taking a vehicle inspection station as a typical automotive service enterprise example, and combined with the credibility measure of fuzzy set theory, this work presents new fuzzy cost-profit tradeoff FLA models with regional constraints. A hybrid algorithm integrating fuzzy simulation and genetic algorithms(GA) is proposed to solve the proposed models. Some numerical examples are given to illustrate the proposed models and the effectiveness of the proposed algorithm.

关键词： Cost-profit tradeoff Credibility theory Fuzzy simulation Fuzzy programming Genetic algorithm

“One stone, two birds”: Salt template enabling porosity engineering and single metal atom coordinating toward high-performance zinc-ion capacitors

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Journal of Energy Chemistry 2025年第1期 637-645页

作者： Chunliu Zhu Huanyu Liang Ping Li chenglong Qiu Jingyi Wu Jingwei chen Weiqian tian Yue Zhu Zhi Li Huanlei Wang School of Materials Science and Engineering Ocean University of China Department of Chemical and Materials Engineering University of Alberta

Zinc-ion hybrid capacitors （ZIHCs） have received increasing attention as energy storage devices owing to their low cost,high safety,and environmental ***,their progress has been hampered by low energy and power density,as well as unsatisfactory long-cycle stability,mainly due to the lack of suitable electrode *** this context,we have developed manganese single atoms implanted in nitrogen-doped porous carbon nanosheets （MnSAs/NCNs） using a metal salt template method as cathodes for *** metal salt serves a dual purpose in the synthesis process:It facilitates the uniform dispersion of Mn atoms within the carbon matrix and acts as an activating agent to create the porous *** applied in ZIHCs,the MnSAs/NCNs electrode demonstrates exceptional performance,including a high capacity of 203 m Ah g-1,an energy density of 138 Wh kg-1at 68 W kg-1,and excellent cycle stability with 91%retention over 10,000 *** calculations indicate that the introduced Mn atoms modulate the local charge distribution of carbon materials,thereby improving the electrochemical *** work demonstrates the significant potential of carbon materials with metal atoms in zinc-ion hybrid capacitors,not only in enhancing electrochemical performance but also in providing new insights and methods for developing high-performance energy storage devices.

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MetaDTA：一款诊断试验准确性Meta分析在线应用程序

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中国全科医学 2025年第8期28卷 1023-1032页

作者：杨水华姚桂英田晨晏毅龙刘嘉艺王佳佳田金徽牛猛葛龙兰州大学公共卫生学院卫生政策与管理学系甘肃省循证医学重点实验室兰州大学循证社会科学研究中心山东省济南市妇幼保健院兰州大学第一临床医学院兰州大学基础医学院循证医学中心兰州大学第一医院放射科

MetaDTA是一款对诊断试验准确性研究进行Meta分析的在线、交互式应用程序，该应用程序调用R软件中lme4和shiny程序包实现统计分析并建立交互式用户界面。该应用程序无需用户了解任何有关统计和编程的知识，也无需安装任何专业软件，便... 详细信息

MetaDTA是一款对诊断试验准确性研究进行Meta分析的在线、交互式应用程序，该应用程序调用R软件中lme4和shiny程序包实现统计分析并建立交互式用户界面。该应用程序无需用户了解任何有关统计和编程的知识，也无需安装任何专业软件，便于无专业统计知识的用户使用。本文将重点介绍MetaDTA平台诊断试验准确性的量化、结果可视化、交互式功能等，结合实例向用户介绍该应用程序的具体操作方法，旨在帮助相关研究人员完成诊断准确性研究Meta分析、绘制汇总受试者工作特征（SROC）曲线、绘制纳入研究质量评价结果以及进行敏感性分析。

关键词： MetaDTA 诊断试验准确性研究 Meta分析双变量模型

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Microstructural evolution and corrosion behavior of Al-20Mg_(2)Si composites with trace La addition

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Journal of Materials Science & Technology 2024年第8期175卷 223-234页

作者： Qiuju Zheng Jing Wu tian chen Shuqian Fan Chongqing Institute of Green and Intelligent Technology Chinese Academy of SciencesChongqing 400714China Chongqing School University of Chinese Academy of SciencesChongqing 400714China College of Bioengineering Chongqing UniversityChongqing 400044China

Trace La element was introduced in Al-20Mg_(2)Si composites to regulate the microstructure and corrosion *** modification mechanism of trace La and the corrosion behavior of the newly developed composites were systematically investigated by thermal analysis,microstructural observations and electrochemical *** study reveals that the addition of only 0.10%La can refine the size of the primary Mg_(2)Si phase from 77.6 to 26.7μm,modify its morphology from a coarse dendrite to a fine truncated octahedron and reduce the corrosion current density from 5.96μA cm^(-2) to 3.03μA cm^(-2).Trace La refines the primary Mg_(2)Si phase size by forming a tiny LaAlSi phase which can provide effective heterogeneous nuclei for the primary Mg_(2)Si phase during *** La atoms can selectively adsorb on the{100}facets of the primary Mg_(2)Si phase and suppress the preferential growth of the Mg_(2)Si phase,eventually resulting in the morphological transition of the primary Mg_(2)Si phase from dendrite to truncated octahedron *** enhanced corrosion resistance of the La micro-alloyed Al-20Mg_(2)Si composites can be attributed to the formation of stronger protective surface oxide films and finer primary Mg_(2)Si *** protective oxide films can effectively hinder the penetration of the corrosive medium and the finer primary Mg_(2)Si phase can weaken the localized corrosion tendency of the Al-Mg_(2)Si composites.

关键词： Al-Mg_(2)Si composites Rare earth elements Mg_(2)Si modification Corrosion behavior

Band structure properties of elastic waves propagating in the nanoscaled nearly periodic layered phononic crystals

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Acta Mechanica Solida Sinica 2017年第2期30卷 113-122页

作者： A-Li chen Li-Zhi tian Yue-Sheng Wang Institute of Engineering Mechanics Beijing Jiaotong Uniuersity Beijing 100044 China

The localization factor is used to describe the band structures for P wave propagating normally in the nanoscaled nearly periodic layered phononic crystals. The localization factor is calculated by the transfer matrix method based on the nonlocal elastic continuum *** kinds of nearly periodic arrangements are concerned, i.e., random disorder, quasiperiodicity and defects. The influences of randomly disordered degree of the sub-layer＇s thickness and mass density, the arrangement of quasi-periodicity and the location of defect on the band structures and cut-off frequency are analyzed in detail.

关键词： Elastic wave Nanoscale Nearly periodic Phononic crystal Band structure

High efficient moving object extraction and classification in traffic video surveillance

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Journal of Systems Engineering and Electronics 2009年第4期20卷 858-868页

作者： Li Zhihua Zhou Fan tian Xiang chen Yaowu Inst. of Advanced Digital Technology and Instrument Zhejiang Univ. Hangzhou 310027 P. R. China

Moving object extraction and classification are important problems in automated video surveillance systems. A background model based on region segmentation is proposed. An adaptive single Gaussian background model is used in the stable region with gradual changes, and a nonparametric model is used in the variable region with jumping changes. A generalized agglomerative scheme is used to merge the pixels in the variable region and fill in the small interspaces. A two-threshold sequential algorithmic scheme is used to group the background samples of the variable region into distinct Gaussian distributions to accelerate the kernel density computation speed of the nonparametric model. In the feature-based object classification phase, the surveillance scene is first partitioned according to the road boundaries of different traffic directions and then re-segmented according to their scene localities. The method improves the discriminability of the features in each partition. AdaBoost method is applied to evaluate the relative importance of the features in each partition respectively and distinguish whether an object is a vehicle, a single human, a human group, or a bike. Experimental results show that the proposed method achieves higher performance in comparison with the existing method.

关键词： background model nonparametric model adaptive single Gaussian model object classification

Identification and fine mapping of quantitative trait loci for the number of vascular bundle in maize stem

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Journal of Integrative Plant Biology 2016年第1期58卷 81-90页

作者： cheng Huang Qiuyue chen Guanghui Xu Dingyi Xu Jinge tian Feng tian Department of Plant Genetics and Breeding National Maize Improvement Center of China China Agricultural University

Studies that investigated the genetic basis of source and sink related traits have been widely ***, the vascular system that links source and sink received much less attention. When maize was domesticated from its wild ancestor, teosinte, the external morphology has changed dramatically; however, less is known for the internal anatomy changes. In this study, using a large maize-teosinte experimental population, we performed a high-resolution quantitative trait locus（QTL） mapping for the number of vascular bundle in the uppermost internode of maize *** results showed that vascular bundle number is dominated by a large number of small-effect QTLs, in which a total of 16 QTLs that jointly accounts for 52.2% of phenotypic variation were detected, with no single QTL explaining more than 6% of variation. Different from QTLs for typical domestication traits, QTLs for vascular bundle number might not be under directional selection following *** Near Isogenic Lines（NILs） developed from heterogeneous inbred family（HIF）, we further validated the effect of one QTL qVb9-2 on chromosome 9 and fine mapped the QTL to a 1.8-Mb physical region. This study provides important insights for the genetic architecture of vascular bundle number in maize stem and sets basis for cloning of qVb9-2.

关键词： Fine-mapping genetic architecture maize quantitativetrait locus vascular bundle number