检索结果-南通市图书馆

A Modeling and Probabilistic Reasoning Method of Dynamic Uncertain Causality Graph for Industrial Fault Diagnosis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2014年第3期11卷 288-298页

作者： chun-ling dong Qin Zhang Shi-Chao Geng Department of Geographical Information System Shandong Normal University School of Computer Science and Engineering Beihang University Institute of Nuclear and New Energy Technology Tsinghua University

Online automatic fault diagnosis in industrial systems is essential for guaranteeing safe, reliable and efficient ***, difficulties associated with computational overload, ubiquitous uncertainties and insufficient fault samples hamper the engineering application of intelligent fault diagnosis technology. Geared towards the settlement of these problems, this paper introduces the method of dynamic uncertain causality graph, which is a new attempt to model complex behaviors of real-world systems under uncertainties. The visual representation to causality pathways and self-relied "chaining" inference mechanisms are analyzed. In particular, some solutions are investigated for the diagnostic reasoning algorithm to aim at reducing its computational complexity and improving the robustness to potential losses and imprecisions in observations. To evaluate the effectiveness and performance of this method, experiments are conducted using both synthetic calculation cases and generator faults of a nuclear power plant. The results manifest the high diagnostic accuracy and efficiency, suggesting its practical significance in large-scale industrial applications.

关键词： Fault diagnosis causality model probabilistic graphical model uncertain knowledge representation weighted logic inference.

Optimization of a dynamic uncertain causality graph for fault diagnosis in nuclear power plant

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2017年第3期28卷 59-67页

作者： Yue Zhao Francesco Di Maio Enrico Zio Qin Zhang chun-ling dong Jin-Ying Zhang Institute of Nuclear and New Energy Technology of Tsinghua University Beijing 100084 China Energy Department Politecnico di Milano 20156 MilanItaly Chair System Science and the Energy Challenge Fondation Electricite′ de France (EDF) CentraleSupe′lec Universite Paris Saclay 92290 Chatenay-Malabry France Department of Computer Science and Technology Tsinghua University Beijing 100084 China Department of Economic and Management North China Electric Power University Beijing 102206 China

Fault diagnostics is important for safe operation of nuclear power plants(NPPs). In recent years, data-driven approaches have been proposed and implemented to tackle the problem, e.g., neural networks, fuzzy and neurofuzzy approaches, support vector machine, K-nearest neighbor classifiers and inference methodologies. Among these methods, dynamic uncertain causality graph(DUCG)has been proved effective in many practical cases. However, the causal graph construction behind the DUCG is complicate and, in many cases, results redundant on the symptoms needed to correctly classify the fault. In this paper, we propose a method to simplify causal graph construction in an automatic way. The method consists in transforming the expert knowledge-based DCUG into a fuzzy decision tree(FDT) by extracting from the DUCG a fuzzy rule base that resumes the used symptoms at the basis of the FDT. Genetic algorithm(GA) is, then, used for the optimization of the FDT, by performing a wrapper search around the FDT: the set of symptoms selected during the iterative search are taken as the best set of symptoms for the diagnosis of the faults that can occur in the system. The effectiveness of the approach is shown with respect to a DUCG model initially built to diagnose 23 faults originally using 262 symptoms of Unit-1 in the Ningde NPP of the China Guangdong Nuclear Power Corporation. The results show that the FDT, with GA-optimized symptoms and diagnosis strategy, can drive the construction of DUCG and lower the computational burden without loss of accuracy in diagnosis.

关键词： Dynamic uncertain causality graph Fault diagnosis Classification Fuzzy decision tree Genetic algorithm Nuclear power plant

Myotonic dystrophy type 1 presenting with dyspnea:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第20期10卷 7060-7067页

作者： Yu-Xi Jia chun-ling dong Jia-Wei Xue Xiao-Qin Duan Ming-Yu Xu Xiao-Min Su Ping Li Department of Orthopedics The Second Hospital of Jilin UniversityChangchun 130041Jilin ProvinceChina Application Demonstration Center of Precision Medicine Molecular Diagnosis The Second Hospital of Jilin UniversityChangchun 130041Jilin ProvinceChina Department of Respiratory and Critical Care Medicine The Second Hospital of Jilin UniversityChangchun 130041Jilin ProvinceChina Department of Rehabilitation Medicine The Second Hospital of Jilin UniversityChangchun 130041Jilin ProvinceChina Department of Developmental Pediatrics The Second Hospital of Jilin UniversityChangchun 130041Jilin ProvinceChina

BACKGROUND Myotonic dystrophy type 1(DM1)is a genetic neuromuscular disease involving multiple systems,especially the cardiopulmonary *** clinical phenotype of DM1 patients is highly variable,which limits early diagnosis and *** the present study,we reported a 35-year-old female DM1 patient with dyspnea as the primary onset clinical manifestation,analyzed her family's medical history,and reviewed related *** SUMMARY A 35-year-old woman was admitted to the hospital with dyspnea of 1 mo duration,and sleep apnea for 3 *** respiratory pattern and effort were normal,but limb muscle tension was *** into the patient's medical history revealed that she might have hereditary neuromuscular *** showed that her myotonia potentials were visible in the resting state of the examined muscles,with decreased motor unit potential time limit and *** testing for DM1 revealed that the cytosine-thymine-guanine(CTG)repeat number of the DMPK gene exceeded 50,while cytosine-CTG expansion in intron 1 of ZNF9 gene was<30 *** patient was diagnosed with *** DM1 is a genetic neuromuscular disease involving multiple systems,and the clinical phenotype in DM1 is extremely *** patients with DM1 may be presented at the respiratory department because of dyspnea,which should be cautioned by the *** may be no obvious or specific symptoms in the early stage of disease,and clinicians should improve their understanding of DM1 and make an early diagnosis,which will improve patients’quality of life.

关键词： Myotonic dystrophy type 1 DMPK gene Respiratory insufficiency Sleep apnea Non-invasive ventilation

π-conjugated chromophore functionalized high-nuclearity titanium-oxo clusters containing structural unit of anatase for photocatalytic selective oxidation of sulfides

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第4期43卷 1736-1746页

作者： ling-Rong Liao dong-chun Zheng Pin-Xi Ou Qi-Xin Zhao Wei-Min Xuan Qi Zheng State Key Laboratory for Modification of Chemical Fibers and Polymer Materials&College of Materials Science and Engineering Donghua UniversityShanghai201620China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials and College of Chemistry and Chemical Engineering Donghua UniversityShanghai 201620China

N-doping has significant influence in manipulating the properties of TiO_(2),and this has stimulated the development of N-donor-functionalized titanium-oxo clusters(TOCs)as molecular models to study the structure-property ***,the structural type and photoresponsive application are still limited for such TOCs,especially regarding the high-nuclearity TOCs that contain structure unit of TiO_(2)for ***,we showed the synthesis of a series of high-nuclearity TOCs 1-3 compounds usingπ-conjugated 1,10-phenanthroline(phen)as chromophore and N-donor functional *** 1 features cocrystal structure composed of one[Ti_(26)]~(2+)and half[Ti_(22)]~(2+),which renders it as the first cocrystallized TOC containing two positively charged species and phen-functionalized TOC showing the highest nuclearity up to 37 Ti *** adjusting the synthetic conditions,the individual{Ti_(22)}and{Ti_(26)}clusters can also be isolated as Compounds 2 and 3,*** core structure of{Ti_(22)}is mainly constructed from four lacunary{Ti_(4)}derived from pentagonal{Ti(Ti)_5}unit,while{Ti_(26)}is built from four complete{Ti(Ti)_5}***,a{Ti_8O_(14)}structure unit of anatase TiO_(2)can be identified in{Ti_(26)}.Based on the unique structural features and proper photophysical and photochemical properties of Compounds 1-3,they are applied for photocatalytic *** to the presence of anatase structure unit in{Ti_(26)}and the synergistic effect from{Ti_(22)}and{Ti_(26)},the catalytic performance presents in the order of Compound 1>Compound 3>Compound *** work provides excellent models to understand the structureproperty relationship from the perspective of cocrystallization and Ti-O binding model and will further promote the application of TOCs as functional catalysts for organic transformation.

关键词： Titanium-oxo cluster Molecular model of anatase TiO_(2) High nuclearity π-conjugated chromophore Photocatalytic sulfoxidation

Breaking the efficiency limitations of dissipative Kerr solitons using nonlinear couplers

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 88-94页

作者： Ming Li Xiao-Xiao Xue Yan-Lei Zhang Xin-Biao Xu chun-Hua dong Guang-Can Guo Chang-ling Zou CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Centerfor Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Department of Electronic Engineering Beijing National Research Center for Information Science and TechnologyTsinghua University Beijing 100084China

Dissipative Kerr solitons(DKS) have long been suffering from poor power conversion efficiency when driven by continuous-wave lasers. By deriving the critical coupling condition of a multimode nonlinear optics system in a generalized theoretical framework,two efficiency limitations of the conventional pump method of DKS are revealed: the effective coupling rate is too small and is also power-dependent. A general approach is provided to resolve this challenge by introducing two types of nonlinear couplers to couple the soliton cavity and CW input through nonlinear processes. The collective coupler opens multiple coupling channels and the self-adaptive coupler builds a power-independent effective external coupling rate to the DKS for approaching the generalized critical coupling condition, which promises near-unity power conversion efficiencies. For instance, a conversion efficiency exceeding 90% is predicted for aluminum nitride microrings with a nonlinear coupler utilizing second-harmonic generation. The mechanism applies to various nonlinear processes, including Raman and Brillouin scattering, and thus paves the way for micro-solitons toward practical applications.

关键词： Kerr frequency comb conversion efficiency nonlinear coupler

Insight study of rare earth elements in PM_(2.5)during five years in a Chinese inland city:Composition

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 439-449页

作者： Yi-Wen Shen Chang-Xian Zhao Hao Zhao Shuo-Fei dong Qi Guo Jiao-Jiao Xie Mei-ling Lv chun-Gang Yuan Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control Department ofEnvironmental Science&EngineeringNorth China Electric Power UniversityBaoding 071000China MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and EngineeringNorth China Electric Power UniversityBeijing 102206China Agilent Technologies Co.Ltd.(China) Beijing 100102China

The booming development of rare earth industry and the extensive utilization of its products accompanied by urban development have led to the accelerated accumulation of rare earth elements(REEs)as emerging pollutants in atmospheric *** this study,the variation of REEs in PM_(2.5)with urban(a non-mining city)transformation was investigated through five consecutive years of sample *** compositional variability and provenance contribution of REEs in PM_(2.5)were characterized,and the REEs exposure risks of children and adults via inhalation,ingestion and dermal absorption were also *** results showed an increase in the total REEs concentration from 46.46±35.16 mg/kg(2017)to 81.22±38.98 mg/kg(2021)over the five-year period,with Ce and La making the largest *** actual increment of industrial and traffic emission source among the three pollution sources was 1.34 ng/m^(3).Coal combustion source displayed a downward *** was the main exposure pathway for REEs in PM_(2.5)for both children and *** contributed the most to the total intake of REEs in PM_(2.5)among the population,followed by La and *** exposure risks of REEs in PM_(2.5)in the region were relatively low,but the trend of change was of great *** was strongly recommended to strengthen the concern about traffic-related non-exhaust emissions of particulate matter.

关键词： Rare earth elements Exposure risks Pollution sources Traffic-related non-exhaust emissions

Exploring the potential of constructing a hybrid supercapacitor with FeCoNi-LDH porous material containing oxygen vacancies for high-performance energy storage applications

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第9期17卷 8134-8144页

作者： Jihao Su ling Yang Dengbin Yu Shaojun dong State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China College of Chemistry Jilin UniversityChangchun 130022China University of Science and Technology of China Hefei 230026China

A significant challenge in developing high-performance hybrid supercapacitors(HSCs)is the need to reasonably construct advanced architectures that consist of various components and exhibit superior electrochemical capacitance *** FeCoNi-layered double hydroxide(FeCoNi-LDH)porous material has a specific capacitance of 1960 F·g^(-1)when used as the anode material at 1 A·g^(-1).The FeCoNi-LDH material exhibits nanoplates with a distinct spindle morphology on their *** to the combined action of the three metals and abundant oxygen vacancies,they exhibit unique rate performance and cycle *** electronic structure of LDH and the regulation of oxygen vacancy were confirmed by density functional theory(DFT)*** suggests that the strength of hydroxide can reduce the energy required for oxygen vacancy formation in FeCoNi-LDH nanosheets and enhance ion and charge transfer,as well as electrolyte adsorption on the electrode *** FeCoNi-LDH//activated carbon(AC)HSC has an energy density of 53.2 Wh·kg^(-1)at a power density of 800 W·kg^(-1),surpassing other devices composed of comparable materials during the same *** study made significant advances in the design and synthesis of a ternary LDH porous structure with distinct oxygen vacancies,as well as its potential application in electrochemical energy storage.

关键词： oxygen vacancy FeCoNi-layered double hydroxide(FeCoNi-LDH) theory calculation electrode material hybrid supercapacitor

Impurity formation mechanism of silicon carbide crystals smelted by Acheson process

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第6期31卷 1367-1375页

作者： dong Feng Hong-qiang Ru Xu-dong Luo Jie-gang You ling Zhang School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) Institute of Advanced CeramicsSchool of Materials Science and EngineeringNortheastern UniversityShenyang 110819LiaoningChina Liaoning Institute of Science and Technology Benxi 117004LiaoningChina

In order to further promote the application of SiC refractories in modern steel metallurgy,the occurrence forms and formation mechanism of impurities in SiC crystals smelted by Acheson process were *** techniques of inductively coupled plasma-atomic emission spectrometry,X-ray diffraction,and scanning electron microscopy were combined to examine the types and occurrence forms of impurities in smelted SiC *** results showed that the main impurities in the SiC are free Si,free C,oxides(CaO·Al_(2)O_(3)·2SiO_(2),3Al_(2)O_(3)·2SiO_(2),CaO·SiO_(2) and SiO_(2))and alloy phases(Fe_(x)Si_(y),Fe_(x)Si_(y)Ti_(z) and Fe_(x)Al_(y)Si_(z)).The formation process of impurities during the smelting of SiC can be described as follows:At high temperature,the SiO_(2) and Fe,Ti related oxide impurities present in the raw materials are reduced to Si,Fe,and Ti metal *** the reduction process,the free Si,Fe_(x)Si_(y) and Fe_(x)Si_(y)Ti_(z) are precipitated from the melt during *** Si primarily exists in aggregated form within the SiC crystal,while the alloy phase is predominantly found at the interface between SiC and free Si,with Fe_(x)Si_(y)Ti_(z) embedded within *** the end of the cooling process,other impurity oxides such as Al_(2)O_(3),CaO,and some unreduced SiO_(2) solidify to form calcium-aluminum-silicate glass phases,predominantly located between SiC *** remaining C from the reaction is mainly dispersed as free C within the SiC crystal and at the interface between SiC and free Si.

关键词： Impurity element Formation mechanism Smelted SiC crystal SiC refractory Occurrence form

Tomographic particle image velocimetry measurement on three-dimensional swirling flow in dual-stage counter-rotating swirler

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第3期37卷 7-20页

作者： Yuyang ZHOU ling dong Mingtao SHANG Jibao LI Akira RINOSHIKA Key Laboratory of Fluid Mechanics of Ministry of Education Beihang UniversityBeijing 100191China School of Mechanical and Automotive Engineering Shanghai University of Engineering ScienceShanghai 201620China AECC Commercial Aircraft Engine Co. Ltd.Shanghai 200241China Department of Mechanical Systems Engineering Yamagata UniversityYamagata 992-8510Japan

Three-Dimensional(3D)swirling flow structures,generated by a counter-rotating dualstage swirler in a confined chamber with a confinement ratio of 1.53,were experimentally investigated at Re=2.3×10^(5)using Tomographic Particle Image Velocimetry(Tomo-PIV)and planar Particle Image Velocimetry(PIV).Based on the analysis of the 3D time-averaged swirling flow structures and 3D Proper Orthogonal Decomposition(POD)of the Tomo-PIV data,typical coherent flow structures,including the Corner Recirculation Zone(CRZ),Central Recirculation Zone(CTRZ),and Lip Recirculation Zone(LRZ),were *** counter-rotating dual-stage swirler with a Venturi flare generates the independence process of vortex breakdown from the main stage and pilot stage,leading to the formation of an LRZ and a smaller CTRZ near the nozzle *** confinement squeezes the CRZ to the corner and causes a reverse rotation flow to limit the shape of the CTRZ.A large-scale flow structure caused by the main stage features an explosive breakup,flapping,and Precessing Vortex Core(PVC).The explosive breakup mode dominates the swirling flow structures owing to the expansion and construction of the main jet,whereas the flapping mode is related to the wake *** limits the expansion of PVC and causes it to contract after the impacting area.

关键词： Coherent structures Dual-stage counter-rotating swirler cup Precessing vortex core Proper orthogonal decomposition Swirling flow Tomographic particle image velocimetry