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Discovering unusual structures from exception using big data and machine learning techniques

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Science Bulletin 2019年第9期64卷 612-616页

作者： Jianshu Jie zongxiang Hu Guoyu Qian Mouyi Weng Shunning Li Shucheng Li Mingyu Hu Dong Chen Weiji Xiao Jiaxin Zheng Lin-Wang Wang Feng Pan School of Advanced Materials Peking UniversityShenzhen Graduate School Materials Science Division Lawrence Berkeley National Laboratory

Recently, machine learning(ML) has become a widely used technique in materials science study. Most work focuses on predicting the rule and overall trend by building a machine learning model. However,new insights are often learnt from exceptions against the overall trend. In this work, we demonstrate that how unusual structures are discovered from exceptions when machine learning is used to get the relationship between atomic and electronic structures based on big data from high-throughput calculation database. For example, after training an ML model for the relationship between atomic and electronic structures of crystals, we find AgO2 F, an unusual structure with both Ag3+and O22à, from structures whose band gap deviates much from the prediction made by our model. A further investigation on this structure might shed light into the research on anionic redox in transition metal oxides of Li-ion batteries.

关键词： Machine learning Gradient boosting decision tree Band gap Unusual structures

浓缩生长因子和血凝块作为支架在牙髓再生术中的疗效比较研究

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口腔医学 2024年第9期44卷 678-684页

作者：谢妮娜魏路明袁长永刘浩刘雨苗刘宗响朱绍跃徐州医科大学口腔医学院江苏徐州221000 徐州医科大学附属口腔医院儿童口腔科江苏徐州221002 徐州医科大学附属口腔医院种植中心江苏徐州221002 徐州医科大学附属口腔医院口腔正畸科江苏徐州221002

目的评价和比较浓缩生长因子(CGF)和血凝块(BC)作为支架在牙髓再生术中的治疗效果。方法将来自18名健康儿童的20颗患有牙髓坏死或根尖周炎的单根年轻恒牙随机分到CGF组和BC组。在CGF组(n=10)中,根尖引血后将CGF置入根管内作为支架。在BC... 详细信息

目的评价和比较浓缩生长因子(CGF)和血凝块(BC)作为支架在牙髓再生术中的治疗效果。方法将来自18名健康儿童的20颗患有牙髓坏死或根尖周炎的单根年轻恒牙随机分到CGF组和BC组。在CGF组(n=10)中,根尖引血后将CGF置入根管内作为支架。在BC组(n=10)中,通过刺激根尖出血,血液进入根管内产生血凝块作为支架。每次复诊进行临床检查及根尖片拍摄。术前及术后24个月进行两次锥形束计算机断层摄影(CBCT)。测量根长、根管壁厚度增加量及新形成的钙化组织体积。结果CGF组根长增加(1.68±0.90)mm,BC组增加(2.36±1.34)mm。CGF组根管壁厚度增加(0.44±0.34)mm,BC组增加(0.50±0.31)mm。根长和根管壁厚度增量两组间差异无统计学意义(P>0.05)。CGF组新形成的钙化组织体积((22.13±19.12)mm^(3))显著少于BC组((42.97±22.69)mm^(3))(P0.05)。40%的CGF病例(4/10)和60%的BC病例(6/10)达到了三级目标(P>0.05)。结论CGF可作为牙髓再生术的支架,但成功率略低于BC组,差异无统计学意义。

关键词：血凝块浓缩生长因子牙髓再生锥形束计算机断层摄影

计入电网损失及社会影响的500kV终端站综合风险评估

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电力系统自动化 2013年第22期37卷 111-117页

作者：杨汾艳兑潇玮唐景星鲁宗相广东电网公司电力科学研究院广东省广州市510080 清华大学电机工程与应用电子技术系北京市100084 电力系统及发电设备控制和仿真国家重点实验室清华大学北京市100084

为了对终端变电站改造方案进行安全评估,针对500kV终端变电站的特点提出了一套工程化的风险评估方法。考虑了电网安全风险、缺供电、设备损坏、社会影响等几种主要的风险因素,基于解析法建立了各类风险的计算模型,并以广东电网某500kV... 详细信息

为了对终端变电站改造方案进行安全评估,针对500kV终端变电站的特点提出了一套工程化的风险评估方法。考虑了电网安全风险、缺供电、设备损坏、社会影响等几种主要的风险因素,基于解析法建立了各类风险的计算模型,并以广东电网某500kV变电站的终端站改造方案作为算例,进行了风险评估,比较了改造前后的风险变化,分析了各类风险所占比例,对几个主要的风险参数进行了灵敏度分析。分析结果表明,设备损坏和缺供电是主要的风险因素,500kV枢纽站进行终端站改造后,其设备损坏风险显著降低,缺供电风险有所上升,综合风险下降。

关键词：终端变电站风险评估设备损失风险社会影响风险

Discovery of space aromaticity in transition–metal monoxide crystal Nb3O3 enabled by octahedral Nb6 structural units

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Science Bulletin 2020年第5期65卷 367-372页

作者： zongxiang Hu Guoyu Qian Shunning Li Luyi yang Xin Chen Mouyi Weng Wenchang Tan Feng Pan School of Advanced Materials Peking UniversityShenzhen Graduate SchoolShenzhen 518055China

An octahedral Nb6 structural unit with space aromaticity is identified for the first time in a transition–metal monoxide crystal Nb3O3 by ab initio *** strong Nb–Nb metallic bonding facilitates the formation of stable octahedral Nb6 structural units and the release of delocalization ***,the Nb atoms in continuously connected Nb6 structural units share their electrons with each other in a continuous space of framework,so that the electrons are uniformly *** newly discovered aromaticity in the octahedral Nb6 structural units extends the range of aromatic compounds and broadens our vision in structural chemistry.

关键词： Nb–Nb metallic bonding Octahedral Nb6 Transition–metal monoxides Aromaticity Structural unit

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基于新负荷削减模型的UPFC优化配置

电力系统自动化 2010年第13期34卷 6-10,15页

作者：李立鲁宗相邱阿瑞电力系统国家重点实验室清华大学电机系北京市100084

电力系统中使用统一潮流控制器(UPFC)可以明显改善运行状况。建立了UPFC的注入潮流模型和运行可靠性模型,以及UPFC安装费用和系统切负荷费用模型。基于运行可靠性模型提出了含UPFC的负荷削减模型,该模型通过UPFC的控制消除潮流越限和电... 详细信息

电力系统中使用统一潮流控制器(UPFC)可以明显改善运行状况。建立了UPFC的注入潮流模型和运行可靠性模型,以及UPFC安装费用和系统切负荷费用模型。基于运行可靠性模型提出了含UPFC的负荷削减模型,该模型通过UPFC的控制消除潮流越限和电压越限,以降低切负荷出现的概率,提高系统可靠性。最后给出了基于该模型的多UPFC配置方法,该方法的目标是在保证可靠性水平满足要求的前提下保证系统总费用最少。RTS 79系统的仿真表明,所提出的模型和配置方法优于传统模型和配置方法。

关键词：运行可靠性模型统一潮流控制器切负荷期望负荷削减模型电力系统

Identification of New Resistance Loci Against Sheath Blight Disease in Rice Through Genome-Wide Association Study

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Rice science 2019年第1期26卷 21-31页

作者： CHEN zongxiang FENG Zhiming KANG Houxiang ZHAO Jianhua CHEN Tianxiao LI Qianqian GONG Hongbing ZHANG Yafang CHEN Xijun PAN Xuebiao LIU Wende WANG Guoliang ZUO Shimin Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou University State Key Laboratory for Biology of Plant Diseases and Insect Pests/Institute of Plant Protection Chinese Academy of Agricultural Sciences Zhenjiang Agricultural Research Institute

Sheath blight(SB) caused by the soil borne pathogen Rhizoctonia solani is one of the most serious global rice diseases. Breeding resistant cultivar is the most economical and effective strategy to control the disease. However, no rice varieties are completely resistant to SB, and only a few reliable quantitative trait loci(QTLs) linked with SB resistance have been identified to date. In this study, we conducted a genome-wide association study(GWAS) of SB resistance using 299 varieties from the rice diversity panel 1(RDP1) that were genotyped using 44 000 high-density single nucleotide polymorphism(SNP) markers. Through artificial inoculation, we found that only 36.5% of the tested varieties displayed resistance or moderate resistance to SB. In particular, the aromatic and aus sub-populations displayed higher SB resistance than the tropical japonica(TRJ), indica and temperate japonica sub-populations. Seven varieties showed similar resistance levels to the resistant control YSBR1. GWAS identified at least 11 SNP loci significantly associated with SB resistance in the three independent trials, leading to the identification of two reliable QTLs, qSB-3 and qSB-6, on chromosomes 3 and 6. Using favorable alleles or haplotypes of significantly associated SNP loci, we estimated that both QTLs had obvious effects on reducing SB disease severity and can be used for enhancing SB resistance, especially in improving SB resistance of TRJ sub-population rice varieties. These results provided important information and genetic materials for developing SB resistant varieties through breeding.

关键词： genome-wide association study quantitative trait locus rice sheath blight plant height

Initial Exploration of Wind Farm Cluster Hierarchical Coordinated Dispatch Based on Virtual Power Generator Concept

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CSEE Journal of Power and Energy Systems 2015年第2期1卷 62-67页

作者： zongxiang Lu Xi Ye Ying Qiao Yong Min State Key Lab of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China

China has made many strides in large-scale development and centralized integration of wind power in recent *** wind power penetration of some regions has reached a high level,which brings significant challenges for power system dispatch due to the inherent variability and uncertainty of wind *** increase the dispatch capabilities of wind power generation,the spatial smoothing effect among adjacent wind farms needs to be fully *** paper presents the concept of hierarchical coordinated dispatch for wind power based on a new concept of a virtual power *** spatial smoothing effect of wind power is analyzed ***,the virtual power generator method of a wind farm cluster is defined and ***,the hierarchical coordinated dispatch mode is compared with an existing wind power dispatch mode for individual wind ***,the proposed concept is implemented on a simulation case to demonstrate applicability and effectiveness.

关键词： Hierarchical coordinated dispatch smoothing effect virtual power generator wind farm cluster

多重调适及其规则生成:西部后发地区治理创新的管委会驱动逻辑研究

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中国行政管理 2023年第7期39卷 110-119页

作者：曲纵翔中央民族大学管理学院北京100081

国家级新区作为我国独特的综合功能区,其治理模式有多种类别,管委会始终是最主要的治理主体。管委会在担负一定行政功能的同时还具有招商引资等区域经营职能。国家级新区在西部后发地区的设立对于我国推动区域协调发展有重要战略意义。... 详细信息

国家级新区作为我国独特的综合功能区,其治理模式有多种类别,管委会始终是最主要的治理主体。管委会在担负一定行政功能的同时还具有招商引资等区域经营职能。国家级新区在西部后发地区的设立对于我国推动区域协调发展有重要战略意义。关于管委会如何提升经济后发地区的长期创新效能,本研究以兰州新区为典型案例,探究管委会在组织结构、职能架构、政务理念等维度自发调适对提升治理效能的作用。研究发现,以开发区带动西部后发地区发展能够通过多重调适及其规则化形成符合地方实际的治理创新方案。

关键词：国家级新区管委会调适与规则地方治理兰州新区

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双馈风电场自动电压协调控制策略

电力系统自动化 2010年第5期34卷 96-101页

作者：乔颖鲁宗相徐飞清华大学电机系电力系统国家重点实验室北京市100084

依据当前风速与电网状态进行实时在线的电压无功控制(VQC)是大型风电场参与系统优化运行、改善局部电网电压水平的关键技术。以风电场自动电压控制(AVC)的3层结构模型为基础,讨论了升压站集中补偿设备和双馈风力发电机的协调控制策略。... 详细信息

依据当前风速与电网状态进行实时在线的电压无功控制(VQC)是大型风电场参与系统优化运行、改善局部电网电压水平的关键技术。以风电场自动电压控制(AVC)的3层结构模型为基础,讨论了升压站集中补偿设备和双馈风力发电机的协调控制策略。针对双馈风电场AVC优化,借鉴变电站综合无功控制方法,采用近似线性化方法推导出一种风电场AVC的分区图简化策略,为风力发电机群与集中补偿设备的协调优化提供了一种新型实用化方法。进一步考虑风能随机性与波动性的影响,对分区图策略进行了改进。该改进可显著提高电压合格率,减少设备调节次数。对中国北方某风电场仿真计算验证了所提出的模型与方法的有效性。

关键词：双馈风力发电系统风电场自动电压控制协调控制