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Study of the correlations between main shocks and aftershocks and aftershock synthesis method

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Earthquake Engineering and Engineering Vibration 2019年第4期18卷 759-775页

作者： Zhang Yingnan zhi Xudong fan Feng Key Laboratory of Structural Engineering Disaster Control of Education Ministry (Harbin Institute of Technology) Harbin 150090 China Key Laboratory of Civil Engineering Intelligent Disaster Prevention and Mitigation Control of Ministry of Industry and Information (Harbin Institute of Technology) Harbin 150090 China School of Civil Engineering Harbin Institute of Technology Harbin 150090 China

To consider the infl uence of aftershocks in engineering design, the correlations between main shocks and aftershocks should be examined, and an aftershock simulation method with main shock ground motions needs to be developed. In this study, the data on the sequences of main shock–aftershock ground motions and other related parameters were collected. Using these data, correlations between the magnitude, frequency, duration and energy of the main shock–aftershock ground motions were investigated. The results showed that the magnitude of the aftershock can be larger than that of the main shock. The shapes of the Fourier amplitude spectra of main shocks and aftershocks were similar;however, the predominant frequency and high-frequency components of the aftershock tended to be larger. Considering the magnitude diff erence between the main shock and the aftershock, the correlation of durations was explored. Additionally, a new concept, the duration ratio, was defi ned to describe the concentration of seismic energy release, and main shock energy was strongly positively correlated with the energy attenuated during the main shock–aftershock sequence. Finally, based on these results regarding correlation, an aftershock synthesis using recorded main shock ground motions was constructed with the trigonometric series method for seismic design, and some examples are given to analyze the rationality of this synthetic method.

关键词： main shock-aftershock sequence correlation aftershock synthesis seismic design

Simplified design method and seismic performance of space trusses with consideration of the influence of the stiffness of their lower supporting columns

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Earthquake Engineering and Engineering Vibration 2016年第2期15卷 401-409页

作者： fan Feng Sun menghan zhi Xudong Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology School of Civil Engineering Harbin Institute of Technology

Static and dynamic force performance of two types of space truss structures i.e. square pyramid space truss（SPST） and diagonal on square pyramid space truss（DSPST）, are studied to determine the effect of stiffness of their lower supporting members. A simplified model for the supporting columns and the equivalent spring mass system are presented. Furthermore, the feasibility of the simplified model is demonstrated through theoretical analysis and examples of comparative analysis of the simplified model with the entire model. Meanwhile, from the elastic analysis under frequently occurring earthquakes and elasto-plastic analysis under seldom occurring earthquakes subjected to TAFT and EL-Centro seismic oscillation it is shown that the simplified method can be encompassed in the results from the normal model. It also showed good agreement between the two methods, as well as greatly improved the computational efficiency. This study verified that the dynamic effect of the supporting structures was under considered in space truss design in the past. The method proposed in the paper has important significance for other space truss structures.

关键词： simplified supporting pyramid stiffness truss verified diagonal elasto columns seldom

Safety-enhanced Polymer Electrolytes with High Ambient-temperature Lithium-ion Conductivity Based on ABA Triblock Copolymers

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Chinese Journal of Polymer Science 2022年第1期40卷 21-28页

作者： Dong Liu fan Wu zhi-Hao Shen Xing-He fan Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCenter for Soft Matter Science and EngineeringCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Liquid electrolytes used in lithium-ion batteries suffer from leakage,flammability,and lithium dendrites,making polymer electrolyte a potential ***,a series of ABA triblock copolymers(ABA-x)containing a mesogen-jacketed liquid crystalline polymer(MJLCP)with a polynorbornene backbone as segment A and a second polynorbornene-based polymer having poly(ethylene oxide)(PEO)side chains as segment B were synthesized through tandem ring-opening metathesis *** block copolymers can self-assemble into ordered morphologies at 200℃.After doping of lithium salts and ionic liquid(IL),ABA-x self-assembles into cylindrical *** MJLCP segments with a high glass transition temperature and a stable liquid crystalline phase serve as physical crosslinking points,which significantly improve the mechanical performance of the polymer *** ionic conductivity of ABA-x/lithium salt/IL is as high as 10-3 S·cm-1 at ambient temperature owing to the high IL uptake and the continuous phase of conducting PEO *** relationship between ionic conductivity and temperature fits the Vogel-Tamman-Fulcher(VTF)*** addition,the electrolyte films are flame retardant owing to the addition of *** polymer electrolytes with good safety and high ambient-temperature ionic conductivity developed in this work are potentially useful in solid lithium-ion batteries.

关键词： ABA triblock copolymer Polymer electrolyte Ionic conductivity Inflammability Cylindrical structure

Holographic superfluid ring with a weak link

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 29-38页

作者： zhi-Hong Li Huai-fan Li Department of Physics Shanxi Datong UniversityDatong 037009China Institute of Theoretical Physics Shanxi Datong UniversityDatong 037009China

We explore the generation of topological defects in the course of a dynamical phase transition in a ring with a weak link, i.e., a SSS Josephson junction, from the AdS/CFT correspondence. By setting different parameters of the junction(width, steepness,depth) and the final temperature of the quench, the configurations of the charge density and condensate of the order parameters of the dual field theory are presented. Meanwhile, we observe that in the final equilibrium state, variations in parameters of the junctions only affect the configurations of the charge density and condensate of the order parameters, without altering their values outside the junction. However, variations in the final temperature will directly affect the values of the charge density and condensate of the order parameters outside of the junction. Moreover, in the final equilibrium state, we propose an analytic relation between the gauge-invariant velocity in the two superconducting states in the SSS Josephson junction, which agrees well with the numerical results.

关键词： AdS/CFT correspondence holographic superfluid holographic Josephson junction

Neuronal intranuclear inclusion disease mimicking acute cerebellitis:A case report

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World Journal of Clinical Cases 2020年第23期8卷 6122-6129页

作者： Jiao-Jiao Guo Zi-Yi Wang meng Wang Zong-zhi Jiang Xue-fan Yu Department of Neurology and Neuroscience Center The First Hospital of Jilin UniversityChangchun 130021Jilin ProvinceChina

BACKGROUND Neuronal intranuclear inclusion disease(NIID)is an unusual autosomal dominant,chronic progressive neurodegenerative *** clinical manifestations of NIID are complex and varied,complicating its clinical *** the best of our knowledge,this report is the first to document sporadic adult-onset NIID mimicking acute cerebellitis(AC)that was finally diagnosed by imaging studies,skin biopsy,and genetic *** SUMMARY A 63-year-old man presented with fever,gait unsteadiness,dysarthria,and an episode of *** serum levels of white blood cells and C-reactive protein were significantly elevated.T2-weighted brain magnetic resonance imaging and fluid attenuation inversion recovery sequences showed bilateral high-intensity signals in the medial part of the cerebellar hemisphere beside the *** we initially considered a diagnosis of AC,the patient’s symptoms improved significantly without special treatment,prompting our consideration of ***-weighted imaging showed hyperintensity in the corticomedullary *** biopsy revealed eosinophilic inclusions positive for anti-p62 in epithelial sweat-gland *** repeat expansions in the Notch 2 N-terminal like C gene confirmed the diagnosis of *** For patients with clinical manifestations mimicking AC,the possibility of underlying NIID should be considered along with prompt rigorous examinations.

关键词： Neuronal intranuclear inclusion disease Acute cerebellitis Skin biopsy Genetic testing Magnetic resonance imaging Case report

Enhanced cooperative MAC for wireless local area networks

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The Journal of China Universities of Posts and Telecommunications 2011年第5期18卷 7-14页

作者： JIANG fan fan Jiu-lun CHANG zhi-xian School of Communications and Information Engineering Xi＇an University of Posts and Telecommunications Xi＇an 710121 China

A novel network protocol, enhanced cooperative medium access control （ECoop MAC）, is present in this article. Its function is to guarantee the quality of service （QoS） in wireless local area networks. For the sake of supporting different application scenarios, two proposed schemes, namely E-scheme I for lower priority traffic and E-scheme II for higher priority traffic can be adopted independently or in combination. ECoop MAC takes into account request failure problems, and utilizes cooperative protocol information to boost the system performance as well as to effectively cut control packets overhead. Simulation results show that the proposed algorithm can not only improve network throughput, but also lead to reduced network delays for individual packets.

关键词： MAC protocols cooperative communication game theory QoS

A preliminary study on pollution characteristics of surfactant substances in fine particles in the Beibu Gulf Region of China

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Journal of Environmental Sciences 2021年第4期33卷 363-372页

作者： Zhengzheng Zhang Hong Li Hongyan Liu Yingchen Bai Jinjuan Li Guorui zhi Yanting Yu Wenjun Li Hao Zhang fan meng National Center for Quality Supervision and Test of Building Engineering China Academy of Building ResearchBeijing 100013China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100021China College of Resource and Environmental Engineering Guizhou UniversityGuiyang 550025China Puyang Institute of Environmental Protection Science Puyang 457000China College of Geoscience and Surveying Engineering Chinese University of Mining&TechnologyBeijing 100083China School of Science Chinese University of GeosciencesBeijing 100083China

The pollution characteristics of surfactant substances in fine particles(PM_(2.5))in spring were studied in the Beibu Gulf Region of China,68 samples of PM_(2.5)were collected at Weizhou Island in Beihai City from March 12 to April 17,*** Anionic Surfactant Substances(ASS)and Cationic Surfactant Substances(CSS)in the samples were analyzed using Byethyl Violet Spectrophotometry and Disulfide Blue Spectrophotometry,*** with the data from backward trajectory simulation,the effects of air pollutants from remote transport on the pollution characteristics of surfactant substances in PM_(2.5)in the Beibu Gulf Region were analyzed and *** results showed that the daily mean concentrations of ASS and CSS in spring in the Beibu Gulf Region were 165.20 pmol/m^(3)and 8.05 pmol/m^(3),and the variation ranges were 23.21–452.55 pmol/m^(3)and 0.65–31.31 pmol/m^(3),accounting for 1.82‰±1.65‰and 0.12‰±0.11‰of the mass concentration of PM_(2.5),*** concentrations were lower than those in comparable regions around the *** was no clear correlation between the concentrations of ASS and CSS in PM_(2.5)and the mass concentrations of PM_(2.5).Tourism and air transport had a positive contribution on the concentrations of *** concentration of surfactant substances in PM_(2.5)was significantly impacted by wind speed and wind *** temperature,air pressure and precipitation had little effect on the concentrations of surfactant *** substances in PM_(2.5)significantly impacted *** also showed that the main sources of surfactant substances were from the southern China and Southeast Asia.

关键词： Fine particles Surfactant substances Pollution characteristics Impact factors Beibu gulf region of China

Single neuron network PI control of high reliability linear induction motor for Maglev

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第3期8卷 408-411页

作者： fanG You-tong fan Cheng-zhi College of Electrical Engineering Zhejiang University Hangzhou 310027 China

The paper deals with a new model of linear induction motor (LIM) to improve the reliability of the system. Based on the normal equation circuit of LIM considering the dynamic end effect, an equivalent circuit model with compensation of large end effect is constructed when the end effect force at synchronism is of braking character. The equivalent circuit model is used for secondary-flux oriented control of LIM. Single neuron network PI unit for LIM servo-drive is also discussed. The effectiveness of mathematical model for drive control is verified by simulations.

关键词： Linear induction motor (LIM) Field-oriented control End effect

A statistic comparison of multi-element analysis of low atmospheric fine particles(PM_(2.5)) using different spectroscopy techniques

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Journal of Environmental Sciences 2022年第4期34卷 194-203页

作者： Minkang zhi Kai Zhang Xi Zhang Hartmut Herrmann Jian Gao Khanneh Wadinga Fomba Wei Tang Yuqian Luo Huanhuan Li fan meng State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Faculty of Environmental Engineering The University of Kitakyushu1-1 HibikinoWakamatsuKitakyushuFukuoka 808-0135Japan Atmospheric Chemistry Department(ACD) Leibniz-Institute for Tropospheric Research(TROPOS)Leipzig 04318Germany

Over the past few decades,the metal elements(MEs)in atmospheric particles have aroused great *** well-established techniques have been used to measure particlebound ***,each method has its own advantages and disadvantages in terms of complexity,accuracy,and specific elements of *** this study,the performances of inductively coupled plasma-optical emission spectrometry(ICP-OES)and total reflection X-ray fluorescence spectroscopy(TXRF)were evaluated for quality control to analyze data accuracy and *** statistic methods(Deming regression and significance testing)were applied for intercomparison between ICP-OES and TXRF measurements for same lowloading PM_(2.5)samples in Weizhou *** results from the replicate analysis of standard filters(SRM 2783)and field filters samples indicated that 10 MEs(K,Ca,V,Cr,Mn,Fe,Ni,Cu,Zn,and Pb)showed good accuracies and precision for both *** higher accuracy tended to the higher precision in the MEs analysis *** addition,the interlab comparisons illustrated that V and Mn all had good agreements between ICP-OES and *** measurements of K,Cu and Zn were more reliable by TXRF analysis for low-loading PM_(2.5).ICP-OES was more accurate for the determinations for Ca,Cr,Ni and Pb,owing to the overlapping spectral lines and low sensitivity during TXRF *** measurements of Fe,influenced by low-loading PM_(2.5),were not able to determine which instrument could obtain more reliable *** conclusions could provide reference information to choose suitable instrument for the determination of MEs in low-loading PM_(2.5)samples.

关键词： Multielement analysis Low-loading fine particles Inductively coupled plasma-optical emission spectrometry Total reflection X-ray fluorescence spectroscopy Inter-laboratory comparison