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Short-term solar flare prediction using multi-model integration method

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Research in Astronomy and Astrophysics 2017年第4期17卷 23-34页

作者： Jin-Fu Liu Fei Li Jie Wan da-ren yu School of Energy Science and Engineering Harbin Institute of Technology Harbin 150001 China

A multi-model integration method is proposed to develop a multi-source and heterogeneous model for short-term solar flare prediction. Different prediction models are constructed on the basis of extracted predictors from a pool of observation databases. The outputs of the base models are normal- ized first because these established models extract predictors from many data resources using different prediction methods. Then weighted integration of the base models is used to develop a multi-model integrated model （MIM）. The weight set that single models assign is optimized by a genetic algorithm. Seven base models and data from Solar and Heliospheric Observatory/Michelson Doppler Imager lon- gitudinal magnetograms are used to construct the MIM, and then its performance is evaluated by cross validation. Experimental results showed that the MIM outperforms any individual model in nearly every data group, and the richer the diversity of the base models, the better the performance of the MIM. Thus, integrating more diversified models, such as an expert system, a statistical model and a physical model, will greatly improve the performance of the MIM.

关键词： methods: statistical - Sun activity - Sun' magnetic fields - Sun' photosphere - Sun flares

Particle-in-cell simulation for the effect of magnetic cusp on discharge characteristics in a cylindrical Hall thruster

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Chinese Physics B 2018年第4期27卷 341-345页

作者： Sheng-Tao Liang Hui Liu da-ren yu Laboratory of Plasma Propulsion Harbin Institute of Technology Harbin 150001 China

The cylindrical Hall thruster has the good prospect of serving as a miniaturized electric propulsion device.A 2 D-3 V particle-in-cell plus Monte Carlo（PIC-MCC） method is used to study the effect of the magnetic cusp on discharge characteristics of a cylindrical Hall *** simulation results show that the main ionization region and the main potential drop of the thruster are located at the upstream of the discharge *** the magnetic cusp moves toward the anode side,the main ionization region is compressed and weakened,moving upstream *** ionization near the cusp is enhanced,and the interaction between the plasma and the wall *** simulation results suggest that the magnetic cusp should be located near the channel exit.

关键词： cylindrical Hall thruster PIC-MCC method magnetic cusp

Anomaly Detection Based on Multi-Detector Fusion Used in Turbine

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Journal of Harbin Institute of Technology(New Series) 2013年第1期20卷 113-117页

作者： Hui-Xin He Ning Li Geng-Feng Zheng Xu-Zhou Lin da-ren yu School of Astronautics Harbin Institute of Technology National Institutes for Food and Drug Control Fujian Special Equipment Ispection and Research Institute

In order to improve the gas turbine engine health monitoring capability, using multiple detector fusion method in the monitoring system of gas turbine data monitor. Multi detector frame fusion includes point bias anomaly detector, contextual bias anomaly detector and collective bias anomaly detector, common to analyze the new arrival data, and the possible abnormal state to vote and weighted statistics as a result output. The experimental results show the method can effectively detect the mutation phenomenon, relatively slow changes and abnormal behavior discordant to the conditions. The framework applied to the gas turbine engine can effectively enhance the health diagnosis ability, will be highly applied for real industry.

关键词： fusion industry data anomaly detection

Influence of channel length on discharge performance of anode layer Hall thruster studied by particle-in-cell simulation

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Chinese Physics B 2018年第8期27卷 368-373页

作者： Xi-Feng Cao Hui Liu Wen-Jia Jiang Zhong-Xi Ning Run Li da-ren yu Laboratory of Plasma Propulsion Harbin Institute of Technology（HIT）Harbin 150001China

Hall thruster has the advantages of simple structure, high specific impulse, high efficiency, and long service life, and so on. It is suitable for spacecraft attitude control, North and South position keeping, and other track tasks. The anode layer Hall thruster is a kind of Hall thruster. The thruster has a longer anode area and a relatively short discharge channel. In this paper, the effect of the channel length on the performance of the anode layer Hall thruster is simulated by the PIC simulation method. The simulation results show that the change of the channel length has significant effect on the plasma parameters, such as potential and plasma density and so on. The ionization region mainly concentrates at the hollow anode outlet position, and can gradually move toward the channel outlet as the channel length decreases. The collision between the ions and the wall increases with the channel length increasing. So the proper shortening of the channel length can increase the life of the thruster. Besides, the results show that there is a best choice of the channel length for obtaining the best performance. In this paper, thruster has the best performance under a channel length of 5 mm.

关键词： anode layer Hall thruster channel length potential

Experimental and numerical investigation of a Hall thruster with a chamfered channel wall

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Chinese Physics B 2018年第10期27卷 484-494页

作者： Hong Li Guo-Jun Xia Wei Mao Jin-Wen Liu Yong-Jie Ding da-ren yu Xiao-Gang Wang Plasma Propulsion Laboratory Harbin Institute of Technology Harbin 150001 China Beijing Institute of Control Engineering Beijing 100190 China Department of Physics Harbin Institute of Technology Harbin 150001 China

A discharge channel with a chamfered wall not only has application in the design of modern Hall thrusters, but also exists where the channel wall is eroded, and so is a common status for these units. In this paper, the laws and mechanisms that govern the effect of the chamfered wall on the performance of a Hall thruster are investigated. By applying both experimental measurement and particle-in-cell simulation, it is determined that there is a moderate chamfer angle that can further improve the optimal performance obtained with a straight channel. This is because the chamfering of the wall near the channel exit can enhance ion acceleration and effectively reduce ion recombination on the wall, which is favorable to the promotion of the thrust and efficiency. However, the chamfer angle should not be too large; otherwise, both the density of the propellant gas and the distribution of the plasma potential in the channel are influenced, which is undesirable for efficient propellant utilization and beam concentration. Therefore, it is suggested that the chamfer shape of the channel wall is an important factor that must be carefully considered in the design of Hall thrusters.

关键词： Hall thruster chamfered wall discharge performance physical mechanism

Combining systemic inflammatory response index and albumin fibrinogen ratio to predict early serious complications and prognosis after resectable gastric cancer

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 732-749页

作者： Jing-Yao ren da Wang Li-Hui Zhu Shuo Liu Miao yu Hui Cai School of Clinical Medicine Ningxia Medical UniversityYinchuan 750000Ningxia Hui Autonomous RegionChina General Surgery Clinical Medical Center Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina Key Laboratory of Molecular Diagnostics and Precision Medicine for Surgical Oncology in Gansu Province Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina NHC Key Laboratory of Diagnosis and Therapy of Gastrointestinal Tumor Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina Medical College of Jiangsu University Jiangsu UniversityZhenjiang 212013Jiangsu ProvinceChina The First Clinical Medical School Lanzhou UniversityLanzhou 730000Gansu ProvinceChina

BACKGROUND Gastric cancer has a high incidence and fatality rate,and surgery is the preferred course of ***,patient survival rates are still low,and the incidence of major postoperative complications cannot be *** systemic inflammatory response,nutritional level,and coagulation status are key factors affecting the postoperative recovery and prognosis of gastric cancer *** systemic inflammatory response index(SIRI)and the albumin fibrinogen ratio(AFR)are two valuable comprehensive indicators of the severity and prognosis of systemic inflammation in various medical *** To assess the clinical importance and prognostic significance of the SIRI scores and the AFR on early postoperative outcomes in patients undergoing radical gastric cancer *** We conducted a retrospective analysis of the clinicopathological characteristics and relevant laboratory indices of 568 gastric cancer patients from January 2018 to December *** calculated and compared two indicators of inflammation and then examined the diagnostic ability of combined SIRI and AFR values for serious early postoperative *** scored the patients and categorized them into three groups based on their SIRI and AFR *** analysis was used to compare the three groups of patients the prognostic value of various preoperative SIRI-AFR scores for 5-year overall survival(OS)and disease-free survival(DFS).RESULTS SIRI-AFR scores were an independent risk factor for prognosis[OS:P=0.004;hazards ratio(HR)=3.134;DFS:P<0.001;HR=3.543]and had the highest diagnostic power(area under the curve:0.779;95%confidence interval:0.737-0.820)for early serious complications in patients with gastric *** tumor-node-metastasis stage(P=0.001),perioperative transfusion(P=0.044),positive carcinoembryonic antigen(P=0.014)findings,and major postoperative complications(P=0.011)were factors associated with *** Preoperative SIRI and AFR values were s

关键词： Inflammation Albumin fibrinogen ratio Gastric cancer Complications Prognosis

Double active sites promoting hydrogen evolution activity and stability of CoRuOH/Co_(2)P by rapid hydrolysis

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Chinese Chemical Letters 2024年第7期35卷 206-211页

作者： Bin Dong Ning yu Qiu-yue Wang Jing-Ke ren Xin-yu Zhang Zhi-Jie Zhang Ruo-Yao Fan da-Peng Liu Yong-Ming Chai State Key Laboratory of Heavy Oil Processing College of Chemistry and Chemical EngineeringChina University of Petroleum(East China)Qingdao 266580China

Cobalt-based phosphides show excellent hydrogen evolution reaction(HER)performance,however,improving the intrinsic activity and stability of it in alkaline electrolyte still remains a ***,CoRuOH/Co_(2)P/CF with heterojunction structure was developed by means of molten salt and rapid hydrolysis(30 s).The OH-from rapid surface hydrolysis of Co_(2)P as a hydrogen adsorption site can facilitate the formation of thin CoRuOH layer as a water dissociation site,which may bring out better synergistic effect for alkaline ***,the covering of CoRuOH can improve the stability of Co_(2)P for *** drives at 100 mA/cm^(2),it only requires overpotential of 81 mV in 1.0 mol/L KOH(25℃).Even at higher current density(1000 mA/cm^(2)),CoRuOH/Co_(2)P/CF can also operate stability for at least 100 *** coupling with NiFe-LDH/IF in a two-electrode system,the voltage of NiFe-LDH/IF(+)||CoRuOH/Co_(2)P/CF(-)at 1000 mA/cm^(2)is merely 1.77 V with 100 h,demonstrating great potential for water *** implementation of this work provides a new strategy and reference for the further improvement of transition metal phosphides as HER electrocatalysts.

关键词： CoRuOH/Co_(2)P/CF Enhanced activity and stability Double active site Large current density Hydrogen evolution reaction

TRAIL and Celastrol Combinational Treatment Suppresses Proliferation, Migration, and Invasion of Human Glioblastoma Cells via Targeting Wnt/β-catenin Signaling Pathway

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Chinese Journal of Integrative Medicine 2024年第4期30卷 322-329页

作者： QIN Jing-jing NIU Meng-da CHA Zhe GENG Qing-hua LI yu-lin ren Chun-guang david P.Molloy yu Hua-rong Research Center of Neuroscience School of Basic Medical SciencesChongqing Medical UniversityChongqing(400016)China Laboratory of Developmental Biology Department of Cell Biology and GeneticsSchool of Basic Medical SciencesChongqing Medical UniversityChongqing(400016)China Department of Biochemistry and Molecular Biology School of Basic Medical SciencesChongqing Medical UniversityChongqing(400016)China

Objective To investigate the mechanistic basis for the anti-proliferation and anti-invasion effect of tumor necrosis factor-related apoptosis-induced ligand(TRAIL)and celastrol combination treatment(TCCT)in glioblastoma *** Cell counting kit-8 was used to detect the effects of different concentrations of celastrol(0-16µmol/L)and TRAIL(0-500 ng/mL)on the cell viability of glioblastoma cells.U87 cells were randomly divided into 4 groups,namely control,TRAIL(TRAIL 100 ng/mL),Cel(celastrol 0.5µmol/L)and TCCT(TRAIL 100 ng/mL+celastrol 0.5µmol/L).Cell proliferation,migration,and invasion were detected by colony formation,wound healing,and Transwell assays,*** reverse transcription polymerase chain reaction and Western blotting were performed to assess the levels of epithelial-mesenchymal transition(EMT)markers(zona occludens,N-cadherin,vimentin,zinc finger E-box-binding homeobox,Slug,and β-catenin).Wnt pathway was activated by lithium chloride(LiCl,20 mol/L)and the mechanism for action of TCCT was *** Celastrol and TRAIL synergistically inhibited the proliferation,migration,invasion,and EMT of U87 cells(P<0.01).TCCT up-regulated the expression of GSK-3β and down-regulated the expression of β-catenin and its associated proteins(P<0.05 or P<0.01),including c-Myc,Cyclin-D1,and matrix metalloproteinase(MMP)-*** addition,LiCl,an activator of the Wnt signaling pathway,restored the inhibitory effects of TCCT on the expression of β-catenin and its downstream genes,as well as the migration and invasion of glioblastoma cells(P<0.05 or P<0.01).Conclusions Celastrol and TRAIL can synergistically suppress glioblastoma cell migration,invasion,and EMT,potentially through inhibition of Wnt/β-catenin *** underlies a novel mechanism of action for TCCT as an effective therapy for glioblastoma.

关键词： celastrol Chinese medicine tumor necrosis factor-related apoptosis-induced ligand glioblastoma β-catenin Tripterygium wilfordii

Is Yang-Mills theory unitary in fractional spacetime dimensions?

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 59-64页

作者： Qingjun Jin Ke ren Gang Yang Rui yu Graduate School of China Academy of Engineering Physics Beijing 100193China School of Physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China International Centre for Theoretical Physics Asia-Pacific Hangzhou 310024China School of Physical Science and Technology Inner Mongolia UniversityHohhot 010021China Beijing Computational Science Research Center Beijing 100193China

We present concrete evidence that Yang-Mills theory exhibits non-unitarity in non-integer spacetime *** violation of unitarity stems from evanescent operators that,while vanishing in four dimensions,are non-zero in general d *** demonstrate that these evanescent operators lead to the emergence of both negative-norm states and complex anomalous dimensions.

关键词： gauge field theories field theories in dimensions other than four renormalization