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Electromagnetic characteristic analysis and design of a linear motor used for ultra-high-speed EMS maglev train

Science China Technological Sciences 2024年第6期67卷 1957-1973页

作者： GAO Han SHI TingNa GAO XinMai LEI yanXiao yan Dong GUO Liyan yan yan College of Electrical Engineering Zhejiang University Zhejiang University Advanced Electrical Equipment Innovation Center State Key Laboratory of High-speed Maglev Transportation Technology CRRC Qingdao Sifang Co.Ltd.

The operating speed of the commercial electromagnetic suspension(EMS) maglev train has been over 430 km/h, making it the fastest means of land transportation. With the increasing demands of people traveling, it is necessary to further improve the operating speed of maglev trains. Aiming to examine whether the existing EMS system can meet the requirements of ultra-highspeed operation(more than 600 km/h), the electromagnetic characteristics of an EMS linear motor under the operating speed of 600–1000 km/h fed by a square-wave voltage supply is investigated in this article. First, an electromagnetic field model of the EMS system under the square-wave voltage supply is established to investigate its electromagnetic performance, e.g., the characteristics of phase current, the magnetic flux density, and the electromagnetic force. Second, the relationship between the harmonic components of the air-gap magnetic flux density and electromagnetic force is investigated using the two-dimensional fast Fourier transform(2D-FFT) to reveal the mechanism of electromagnetic force ripple. Third, to address the issues of excessive armature current density and significant electromagnetic force ripple, the linear motor is re-designed by enlarging the stator slot area and reshaping the mover's main magnetic poles. Furthermore, the Taguchi method is used to further improve the electromagnetic characteristics of the linear electric motor. Finally, the effectiveness of the proposed optimal design is validated by the finite-element analysis(FEA) based co-simulation.

关键词： ultra-high-speed maglev transportation electromagnetic suspension (EMS) linear motor electromagnetic force ripple suppression

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A deoxidation thermodynamic model for 304 stainless steel considering multiple-components coupled reactions

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Journal of Iron and Steel Research(International) 2024年第1期31卷 74-91页

作者： yan yan Guang-hao Shang Li-ping Zhang Shao-ying Li Han-jie Guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing100083China Henan Jinhui Stainless Steel Industry Group Co. Ltd.Xuchang461500HenanChina Changge Jinhui Recycling Metal R&D Co. Ltd.Xuchang461500HenanChina

A thermodynamic model for predicting the equilibrium oxygens of 304 stainless steel was developed based on the theory of slag-steel equilibrium,the law of mass conservation,and the ion and molecule coexistence theory.In the developed model,the Fe-Cr-Mn-Si-Al-S-O-melts reaction system and CaO-MgO-CaF_(2)-FeO-MnO-Al_(2)O_(3)-SiO_(2)-Cr2O_(3)slags were considered.The oxygen contents calculated by the model are in good agreement with experimental results and reference data.The equilibrium oxygen contents in 304 stainless steel mainly decrease with increasing binary basicity(w(CaO)/w(SiO_(2)),where w(i)is the mass percentage of component i)and decreasing temperature.Controlling binary basicity at 2.0 while maintaining temperatures lower than 1823 K will keep the oxygen contents in the 304 stainless steel lower than 15×10^(-6).The equilibrium oxygen contents may also be decreased with increasing content of MgO in slags,which is more significant at lower binary basicity.Besides,a small amount of FeO,MnO,and Al_(2)O_(3)(about 0-2.5 wt.%)in slags has little effect on equilibrium oxygen contents.Furthermore,it is found that the[C]-[O]reaction may occur during refining process but will not significantly affect the equilibrium oxygen contents.

关键词： Complex deoxidation Thermodynamic model Ion and molecule coexistence theory 304 stainless steel Slag-steel reaction

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The relationship between compartment models and their stochastic counterparts:A comparative study with examples of the COVID-19 epidemic modeling

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Journal of Biomedical Research 2024年第2期38卷 175-188,I0016-I0018页

作者： Ziyu Zhao Yi Zhou Jinxing Guan yan yan Jing Zhao Zhihang Peng Feng Chen yang Zhao Fang Shao Department of Biostatistics School of Public HealthNanjing Medical UniversityNanjingJiangsu 211166China Nanjing Hanwei Public Health Research Institute Co. LtdNanjingJiangsu 210005China China International Cooperation Center for Environment and Human Health Center for Global HealthNanjing Medical UniversityNanjingJiangsu 211166China The Center of Biomedical Big Data and the Laboratory of Biomedical Big Data Nanjing Medical UniversityNanjingJiangsu 211166China Jiangsu Key Lab of Cancer Biomarkers Prevention and TreatmentCollaborative Innovation Center for Cancer Personalized MedicineNanjing Medical UniversityNanjingJiangsu 211166China

Deterministic compartment models(CMs)and stochastic models,including stochastic CMs and agent-based models,are widely utilized in epidemic modeling.However,the relationship between CMs and their corresponding stochastic models is not well understood.The present study aimed to address this gap by conducting a comparative study using the susceptible,exposed,infectious,and recovered(SEIR)model and its extended CMs from the coronavirus disease 2019 modeling literature.We demonstrated the equivalence of the numerical solution of CMs using the Euler scheme and their stochastic counterparts through theoretical analysis and simulations.Based on this equivalence,we proposed an efficient model calibration method that could replicate the exact solution of CMs in the corresponding stochastic models through parameter adjustment.The advancement in calibration techniques enhanced the accuracy of stochastic modeling in capturing the dynamics of epidemics.However,it should be noted that discrete-time stochastic models cannot perfectly reproduce the exact solution of continuous-time CMs.Additionally,we proposed a new stochastic compartment and agent mixed model as an alternative to agent-based models for large-scale population simulations with a limited number of agents.This model offered a balance between computational efficiency and accuracy.The results of this research contributed to the comparison and unification of deterministic CMs and stochastic models in epidemic modeling.Furthermore,the results had implications for the development of hybrid models that integrated the strengths of both frameworks.Overall,the present study has provided valuable epidemic modeling techniques and their practical applications for understanding and controlling the spread of infectious diseases.

关键词： compartment models agent-based models compartment-agent mixed models comparative study COVID-19

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Research on casing deformation prevention technology based on cementing slurry system optimization

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Petroleum Science 2024年第2期21卷 1231-1240页

作者： yan yan Meng Cai Wen-Hai Ma Xiao-Chuan Zhang Li-Hong Han Yong-Hong Liu State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials CNPC Tubular Goods Research InstituteXi©an710077ShaanxiChina College of Mechanical and Electrical Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province Chengdu610095SichuanChina CNPC Daqing Oilfield Company Daqing163453HeilongjiangChina

The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture mechanism of hollow particles in cement sheath was firstly analyzed by discrete element method, and the effect of hollow particles in cement on casing deformation was investigated by laboratory experiment method. Finally, field test was carried out to verify the improvement effect of the casing deformation based on cement slurry modification. The results show that the formation displacement can be absorbed effectively by hollow particles inside the cement transferring the excessive deformation away from casing. The particles in the uncemented state provide deformation space during formation slipping. The casing with diameter of 139.7 mm could be passed through by bridge plug with the diameter of 99 mm when the mass ratio of particle/cement reaches 1:4. According to the field test feedback, the method based on optimization of cement slurry can effectively reduce the risk of casing deformation, and the recommended range of hollow microbeads content in the cement slurry is between 15% and 25%.

关键词： Cement slurry Hollow ceramsite Casing deformation Formation slip Field test

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LncRNA PCGEM1 facilitates cervical cancer progression via miR-642a-5p/KIF5B axis

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Oncology Research 2024年第7期32卷 1221-1229页

作者： YUANLIN LIU yan LIU yan WANG QIANG WANG yan yan DANDAN ZHANG HUIQIN LIU Department of Obstetrics and Gynecology Shanghai First Maternity and Infant HospitalSchool of MedicineTongji UniversityShanghai200092China Department of Obstetrics and Gynecology The Second People’s Hospital of Nantong CityNantong226002China Department of Obstetrics and Gynecology Affiliated Hospital of Nantong UniversityNantong226002China

At present,the role of many long non-coding RNAs(lncRNAs)as tumor suppressors in the formation and development of cervical cancer(CC)has been studied.However,lncRNA prostate cancer gene expression marker 1(PCGEM1),whose high expression not only aggravates ovarian cancer but also can induce tumorigenesis and endometrial cancer progression,has not been studied in CC.The objective of this study was to investigate the expression and the underlying role of PCGEM1 in CC.The relative expression of PCGEM1 in CC cells was detected by real-time PCR.After the suppression of PCGEM1 expression by shRNA,the changes in the proliferation,migration,and invasion capacities were detected via CCK-8 assay,EdU assay,and colony formation assay wound healing assay.Transwell assay and the changes in expressions of epithelial-to-mesenchymal transition(EMT)markers were determined by western blot and immunoﬂuorescence.The interplay among PCGEM1,miR-642a-5p,and kinesin family member 5B(KIF5B)was conﬁrmed by bioinformatics analyses and luciferase reporter assay.Results showed that PCGEM1 expressions were up-regulated within CC cells.Cell viabilities,migration,and invasion were remarkably reduced after the suppression of PCGEM1 expression by shRNA in Hela and SiHa cells.N-cadherin was silenced,but E-cadherin expression was elevated by sh-PCGEM1.Moreover,by sponging miR-642a-5p in CC,PCGEM1 was veriﬁed as a competitive endogenous RNA(ceRNA)that modulates KIF5B levels.MiR-642a-5p down-regulation partially rescued sh-PCGEM1’s inhibitory effects on cell proliferation,migration,invasion,and EMT process.In conclusion,the PCGEM1/miR-642a-5p/KIF5B signaling axis might be a novel therapeutic target in CC.This study provides a research basis and new direction for targeted therapy of CC.

关键词： Cervical cancer PCGEM1 KIF5B MiR-642a-5p tumorigenesis

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Wavelet-domain feature decoupling for weakly supervised multi-object tracking

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Science China(Information Sciences) 2024年

作者： Yu-Lei LI yan yan yang LU Hanzi WANG Fujian Key Laboratory of Sensing and Computing for Smart City School of InformaticsXiamen University

Multi-object tracking (MOT) aims to discover interesting foreground targets and meanwhile generate robust trajectories of these targets with different data association algorithms based on identity embedding features (Re-ID features)[1] or motion cues [2]. During the past few decades,some advanced MOT methods have achieved considerable progress due to their wide range of applications in modern autonomous driving and intelligent video analysis.

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Prevalence,Characteristics and Treatment of Knee Osteoarthritis in Urban Residents of Beijing,China:A Community-Based Cross-Sectional Study

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Biomedical and Environmental Sciences 2024年第4期37卷 418-422页

作者： ZHOU Jun yan yan DONG Ya Wei LIU Xiao Yu WANG Ping LIN Jia Ming DONG Peng Xuan QUAN Rui WANG Rong Tian MI Bao Hong CHEN Wei Heng Beijing University of Chinese Medicine Third Affiliated Hospital Beijing 100029China Engineering Research Center of Chinese Orthopaedics and Sports Rehabilitation Artificial Intelligent Ministry of EducationBeijing 100029China Beijing Hepingli Community Health Service Center Beijing 100013China Minimally Invasive Joint Surgery Beijing University of Chinese Medicine Third Affiliated HospitalBeijing 100029China

Knee osteoarthritis(KOA)is a common progressive joint disease with chronic pain and movement disorders as the main clinical features.It is a major public health problem worldwide and it imposes serious medical and economic burdens.KOA accounts for nearly four-fifths of the global Osteoarthritis burden and increases with rising obesity and age[1].There are many reasons for the change in disease prevalence and risk factors,such as urbanization,lifestyle changes,population aging,and sex imbalances.

关键词： Osteoarthritis clinical obesity

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The Multiple Roles of Autophagy in Neural Function and Diseases

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Neuroscience Bulletin 2024年第3期40卷 363-382页

作者： yan-yan Li Zheng-Hong Qin Rui Sheng Department of Pharmacology and Laboratory of Aging and Nervous Diseases Jiangsu Key laboratory of Neuropsychiatric DiseasesCollege of Pharmaceutical Sciences of Soochow UniversitySuzhou 215123China

Autophagy involves the sequestration and delivery of cytoplasmic materials to lysosomes,where proteins,lipids,and organelles are degraded and recycled.According to the way the cytoplasmic components are engulfed,autophagy can be divided into macroautophagy,microautophagy,and chaperone-mediated autophagy.Recently,many studies have found that autophagy plays an important role in neurological diseases,including Alzheimer's disease,Parkinson's disease,Huntington's disease,neuronal excitotoxicity,and cerebral ischemia.Autophagy maintains cell homeostasis in the nervous system via degradation of misfolded proteins,elimination of damaged organelles,and regulation of apoptosis and inflammation.AMPK-mTOR,Beclin 1,TP53,endoplasmic reticulum stress,and other signal pathways are involved in the regulation of autophagy and can be used as potential therapeutic targets for neurological diseases.Here,we discuss the role,functions,and signal pathways of autophagy in neurological diseases,which will shed light on the pathogenic mechanisms of neurological diseases and suggest novel targets for therapies.

关键词： Autophagy Neurodegenerative diseases Cerebral ischemia AMPK mTOR Beclin 1 TP53 Endoplasmic reticulum stress

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Advances of Electrochemical and Electrochemiluminescent Sensors Based on Covalent Organic Frameworks

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Nano-Micro Letters 2024年第2期16卷 395-422页

作者： Yue Cao Ru Wu yan‑yan Gao yang Zhou Jun‑Jie Zhu Key Laboratory for Organic Electronics and Information Displays(KLOEID)and Institute of Advanced Materials(IAM) Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023People’s Republic of China State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023People’s Republic of China

Covalent organic frameworks(COFs),a rapidly developing category of crystalline conjugated organic polymers,possess highly ordered structures,large specific surface areas,stable chemical properties,and tunable pore microenvironments.Since the first report of boroxine/boronate ester-linked COFs in 2005,COFs have rapidly gained popularity,showing important application prospects in various fields,such as sensing,catalysis,separation,and energy storage.Among them,COFs-based electrochemical(EC)sensors with upgraded analytical performance are arousing extensive interest.In this review,therefore,we summarize the basic properties and the general synthesis methods of COFs used in the field of electroanalytical chemistry,with special emphasis on their usages in the fabrication of chemical sensors,ions sensors,immunosensors,and aptasensors.Notably,the emerged COFs in the electrochemiluminescence(ECL)realm are thoroughly covered along with their preliminary applications.Additionally,final conclusions on state-of-the-art COFs are provided in terms of EC and ECL sensors,as well as challenges and prospects for extending and improving the research and applications of COFs in electroanalytical chemistry.

关键词： Covalent organic frameworks Electrochemistry Electrochemiluminescence Sensors

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Exosome-encapsulated lncRNA HOTAIRM1 contributes to PM_(2.5)-aggravated COPD airway remodeling by enhancing myofibroblast differentiation

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Science China(Life Sciences) 2024年第5期67卷 970-985页

作者： Huaqi Guo Luo Fei Hengyi Yu yan Li yan Feng Shaowei Wu yan Wang The Ninth People’s Hospital of Shanghai Jiao Tong University School of Medicine Shanghai 200011China School of Public Health Shanghai Jiao Tong University School of MedicineShanghai 200020China Department of Occupational and Environmental Health Sciences School of Public HealthXi’an Jiao Tong University Health Science CenterXi’an 710049China

Emphysema,myofibroblast accumulation and airway remodeling can occur in the lungs due to exposure to atmospheric pollution,especially fine particulate matter(PM_(2.5)),leading to chronic obstructive pulmonary disease(COPD).Specifically,bronchial epithelium-fibroblast communication participates in airway remodeling,which results in COPD.An increasing number of studies are now being conducted on the role of exosome-mediated cell-cell communication in disease pathogenesis.Here,we investigated whether exosomes generated from bronchial epithelial cells could deliver information to normal stromal fibroblasts and provoke cellular responses,resulting in airway obstruction in COPD.We studied the mechanism of exosome-mediated intercellular communication between human bronchial epithelial(HBE) cells and primary lung fibroblasts(pLFs).We found that PM_(2.5)-induced HBE-derived exosomes promoted myofibroblast differentiation in pLFs.Then,the exosomal lncRNA expression profiles derived from PM_(2.5)-treated HBE cells and nontreated HBE cells were investigated using an Agilent Human LncRNA Array.Combining coculture assays and direct exosome treatment,we found that HBE cell-derived exosomal HOTAIRM1 facilitated the myofibroblast differentiation of pLFs.Surprisingly,we discovered that exosomal HOTAIRM1 enhanced p LF proliferation to secrete excessive collagen secretion,leading to airway obstruction by stimulating the TGF-β/SMAD3 signaling pathway.Significantly,PM_(2.5)reduced FEV1/FVC and FEV1 and increased the level of serum exosomal HOTAIRM1 in healthy people;moreover,serum exosomal HOTAIRM1 was associated with PM_(2.5)-related reductions in FEV1/FVC and FVC.These findings show that PM_(2.5)triggers alterations in exosome components and clarify that one of the paracrine mediators of myofibroblast differentiation is bronchial epithelial cell-derived HOTAIRM1,which has the potential to be an effective prevention and therapeutic target for PM_(2.5)-induced COPD.

关键词： PM2.5 exosomal lncRNAs HOTAIRM1 chronic obstructive pulmonary disease

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