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A high torque dual 3-phase permanent magnet vernier machine with strong fault-tolerance

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Science China Technological Sciences 2024年第10期67卷 3275-3284页

作者： XU yuWen WANG Bo WANG RongXin cheng ming HUA Wei School of Electrical Engineering Southeast University

The field modulation effect has been proposed and investigated in various electric machine topologies. Among them, permanent magnet vernier machines(PMVMs) have attained intensive research due to the high torque density and simple ***, the performance of PMVMs in terms of fault tolerance is seldom mentioned. This article proposes a novel dual 3-phase fault-tolerant PMVM with segregated concentric windings. Benefiting from the field modulation effect, the PMVM can generate high torque with low PM flux. The low PM flux also implies small fault currents in the short-circuit case. Therefore, the PMVM exhibits inherent good fault-tolerant capability without sacrificing torque performance. Two independent 3-phase modular winding sets are adopted to improve redundancy. To realize the physical and electrical isolation, each winding set is controlled by a standard 3-phase inverter. The healthy performance and fault tolerance of the proposed machine are evaluated by finite element analysis and verified by experimental tests. The results infer its advantages in healthy conditions and various fault scenarios,including open-circuit, short-circuit, and interturn short-circuit conditions.

关键词： fault-tolerant capability segregated windings field modulation permanent magnet vernier machine

Spatial distribution of supra-permafrost groundwater in the Qinghai-Tibet Engineering Corridor using inversion models

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Advances in Climate Change Research 2024年第1期15卷 31-41页

作者： yu GAO ming-Tang CHAI Wei MA yu-Tao GAO State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China School of Civil and Hydraulic Engineering Ningxia UniversityYinchuan 750021China

Supra-permafrost groundwater(SPG)is a key factor that causes damage to highways and railways in the Qinghai-Tibet Engineering Corridor(QTEC).It is difficult to monitor SPG in the field due to their complex formation mechanisms and movement *** single-site field monitoring studies limit the spatial and temporal precision of SPG spatial *** determine the moisture content of shallow soils and the SPG distribution along the QTEC,this work employed the temperature vegetation dryness index and remote sensing models for groundwater table distribution *** accuracies of the models were validated using mea-surements obtained from different sites in the *** the permafrost zones of the QTEC,72%,22%and 6%of the SPG were located at depths of 0.5-1,1 m,***,79.4%of the area along the Qinghai-Tibet Highway(QTH)(Xidatan-Tanggula)section contained *** these sections with SPG,37.9%have an SPG table at depths of 0.5-0.8 *** study preliminarily explored the SPG distribution in the QTEC with a 30 m *** findings can help improve the spatial scale of SPG research,provide a basis for the analysis of the hydrothermal mechanisms,and serve as a guide in the assessment of operational risks and road structure designs.

关键词： Dryness index Landsat Soil moisture Groundwater level Qinghai-Tibet Engineering Corridor

Construction technology for deep tunnels crossing superhigh-temperature fault zones with high water surges

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Frontiers of Structural and Civil Engineering 2024年第8期18卷 1267-1280页

作者： Yong ZHAO Tingyu ZHU Li yu ming LU Sichuan–Xizang Railway Co. Ltd.Linzhi 860000China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610036China

The harsh environment in tunnels with high geothermal temperatures and humidity can adversely impact machinery,personnel,and *** main causes of specific problems are the unknown mechanisms of local geothermal formation,inappropriate temperature control measures,and insufficient systematic *** this study,three work sections relating to a high geothermal tunnel are:the tunnel face,middle-of-tunnel section,and outside-oftunnel section.A cooling strategy is proposed to offer technical support in achieving comprehensive cooling,overall as well as for each of the ***,a comprehensive geological survey explores the mechanism and exact location of the heat ***,grouting and centralized drainage measures are used to control the heat release of hot *** ventilation,ice chillers and other applicable measures are used to control the ambient ***,a monitoring and early warning system is established to prevent *** cooling strategy has been applied in the field with good results.

关键词： high geothermal tunnels cooling strategy comprehensive cooling measures safety and security

Novel process for facile preparation of mesoporous silica-based materials with controllable pore structure from coal fly ash Author links open overlay panel

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Particuology 2024年第8期91卷 128-137页

作者： Jian-ming Gao Zhen Li Shujia Ma yuanyuan Zhang Fangqin cheng Institute of Resources and Environment Engineering State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste ResourcesShanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related WastesShanxi UniversityTaiyuan 030006China

Extraction of silica from fly ash to produce mesoporous silica materials is one of the most important utilization *** silica could not be synthesized on a large-scale by conventional sol-gel *** this paper,facile preparation of mesoporous silica with controllable pore structure from fly ash by the template-free process via two steps of mineral phase transformation and selective acid etching was *** influence of crystalline structure and acid etching degree on structure of as-synthesized mesoporous silica materials was revealed,as well as mechanism of crystalline structure transformation and pore structure *** results show that mullite and quartz could be transformed into acid-soluble kaliophilite when fly ash reacted with K_(2)CO_(3)at temperature of 800-1100℃.The hexagonal kaliophilite would be transformed into orthorhombic KAlSiO_(4)-O1 phase when the temperature is controlled at 1100℃.Mesoporous silica with specific surface area of 475.93 m^(2)/g and 642.57 m^(2)/g could be synthesized from activated fly ash with kaliophilite and KAlSiO_(4)-O1 phase crystalline *** controlling the degree of acid etching,mesoporous silica materials with different pore structures can be *** paper provides a cost-effective and large-scale process for the preparation of mesoporous silica materials with controllable pore structure from solid waste fly ash.

关键词： Fly ash Mesoporous silica Crystal transformation Acid etching Controllable pore structure

Sparse Modal Decomposition Method Addressing Underdetermined Vortex-Induced Vibration Reconstruction Problem for Marine Risers

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China Ocean Engineering 2024年第2期38卷 285-296页

作者： DU Zun-feng ZHU Hai-ming yu Jian-xing State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation School of Civil EngineeringTianjin UniversityTianjin 300350China

When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real *** problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration ***,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known *** study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal *** the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring.

关键词： motion reconstruction vortex-induced vibration(VIV) marine riser modal decomposition method compressed sensing

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Stercoral perforation of the cecum:A case report

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World Journal of Gastrointestinal Surgery 2024年第4期16卷 1189-1194页

作者： Hung-Chun yu Ta-Wei Pu Jung-cheng Kang Chao-Yang Chen Je-ming Hu Ruei-yu Su Department of Surgery Taichung Armed Forces General HospitalTaichung 411228Taiwan Department of Surgery Tri-Service General HospitalNational Defense Medical CenterTaipei 11490Taiwan Division of Colon and Rectal Surgery Department of SurgeryTri-Service General Hospital Songshan BranchNational Defense Medical CenterTaipei 105Taiwan Division of Colon and Rectal Surgery Department of SurgeryTaiwan Adventist HospitalTaipei 105Taiwan Division of Colon and Rectal Surgery Department of SurgeryTri-Service General HospitalNational Defense Medical CenterTaipei 114Taiwan Department of Pathology Tri-Service General HospitalNational Defense Medical CenterTaipei 105Taiwan Department of Pathology and Laboratory Medicine Taoyuan Armed Forces General HospitalTaoyuan 325Taiwan

BACKGROUND With less than 90 reported cases to date,stercoral perforation of the colon is a rare *** ulceration is thought to occur due to ischemic pressure necrosis of the bowel wall,which is caused by the presence of a stercoraceous *** underscore this urgent surgical situation concerning clinical presentation,surgical treatment,and results,we present the case of a 66-year-old man with a stercoral *** SUMMARY A 66-year-old man with a history of hypertension,hyperlipidemia,and gout presented at the emergency department with lower abdominal pain and a low-grade fever lasting for a few *** computed tomography indicated a suspected bezoar(approximately 7.6 cm)in the dilated cecum,accompanied by pericolic fat stranding,mild proximal dilatation of the ileum,pneumoperitoneum,and minimal ***,feculent peritonitis with isolated cecal perforation were ***,a right hemicolectomy with peritoneal lavage was performed.A histopathological examination supported the intraoperative *** In stercoral perforations,a diagnosis should be diligently pursued,especially in older adults,and prompt surgical intervention should be implemented.

关键词： Acute abdomen Colectomy Peritoneal lavage Pneumoperitoneum Bezoars Case report

Numerical analysis of the correlation between fluid dynamic modes and hydrodynamic noise in flows around a three-dimensional circular cylinder

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Journal of Hydrodynamics 2024年第1期36卷 119-129页

作者： Jia-jia Qin ming-xin Zou yuan Zhuang De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Wuhan Second Ship Design and Research Institute Wuhan430205China

The flow around a circular cylinder for Re=1000 is characterized by flow separation and Karman vortex *** typical flow features can be captured to study the correlation between fluid fields and sound *** this paper,the three-dimensional circular cylinder is taken as the research object,and the probes of surface fluctuating pressure and far field sound pressure are arranged every 10°.The directional diagram and the coherence of fluctuating pressure and sound pressure are *** relationship between the flow mode and hydrodynamic noise is studied by using dynamic mode decomposition(DMD).The characteristics of the dipole and quadrupole sound source term of a long span cylinder are *** results show that at the angles between 30°–120°and 190°–350°,the fluctuating pressure contributes more to the generation of dipole *** quadrupole sound source shows three-dimensional effects,which is more obvious in a cylinder with large spanwise length.

关键词： Pressure coherence dynamic mode decomposition flow-sound correlation circular cylinder

Impact of metabolic syndrome components on clinical outcomes in hypertriglyceridemia-induced acute pancreatitis

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World Journal of Gastroenterology 2024年第35期30卷 3996-4010页

作者： Zhen-Hua Fu Zi-yue Zhao Yao-Bing Liang Dong-yu cheng Jian-ming Luo Hai-Xing Jiang Shan-yu Qin Department of Gastroenterology The First Affiliated Hospital of Guangxi Medical UniversityNanning 530021Guangxi Zhuang Autonomous RegionChina

BACKGROUND The incidence of hypertriglyceridemia(HTG)-induced acute pancreatitis(AP)is steadily increasing in China,becoming the second leading cause of *** complications and outcomes associated with HTG-AP are generally more severe than those seen in AP caused by other ***-AP is closely linked to metabolic dysfunction and frequently coexists with metabolic syndrome or its ***,the impact of metabolic syndrome components on HTGAP clinical outcomes remains *** To investigate the impact of metabolic syndrome component burden on clinical outcomes in *** In this retrospective study of 255 patients diagnosed with HTG-AP at the First Affiliated Hospital of Guangxi Medical University,we collected data on patient demographics,clinical scores,complications,and clinical ***,we analyzed the influence of the presence and number of individual metabolic syndrome components,including obesity,hyperglycemia,hypertension,and low high-density lipoprotein cholesterol(HDL-C),on the aforementioned parameters in HTG-AP *** This study found that metabolic syndrome components were associated with an increased risk of various complications in HTG-AP,with low HDL-C being the most significant risk factor for clinical *** risk of complications increased with the number of metabolic syndrome *** for age and sex,patients with highcomponent metabolic syndrome had significantly higher risks of renal failure[odds ratio(OR)=3.02,95%CI:1.12-8.11)],SAP(OR=5.05,95%CI:2.04-12.49),and intensive care unit admission(OR=6.41,95%CI:2.42-16.97)compared to those without metabolic *** The coexistence of multiple metabolic syndrome components can synergistically worsen the clinical course of HTGAP,making it crucial to monitor these components for effective disease management.

关键词： Hypertriglyceridemia-induced acute pancreatitis Metabolic syndrome High density lipoprotein cholesterol Obesity Hyperglycemia Hypertension Clinical outcomes

Near real-time gravitational wave data analysis of the massive black hole binary with TianQin

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 175-186页

作者： Hong-yu Chen Xiang-yu Lyu En-Kun Li Yi-ming Hu MOE Key Laboratory of TianQin Mission TianQin Research Center for Gravitational Physics&School of Physics and AstronomyFrontiers Science Center for TianQinGravitational Wave Research Center of CNSASun Yat-sen University(Zhuhai Campus)Zhuhai 519082China

Space-borne gravitational wave(GW)detectors can detect the merger of massive black *** early warning and localization of GW events before merging can be used to inform electromagnetic telescopes and conduct multimessenger ***,this requires real-time data transmission and analysis *** geocentric orbit of the space-borne GW detector Tian Qin makes it possible to conduct real-time data *** this study,we develop a search and localization pipeline for massive black hole binaries(MBHBs)with Tian Qin under both regular and real-time data transmission *** demonstrate that,with real-time data transmission,MBHBs can be accurately localized on the *** the approaching merger,each analysis can be finished in only 40 *** an MBHB system at a distance of 1 Gpc,if we receive data every hour,then we can pinpoint its location to within less than 1 deg^(2)on the final day before the merger.

关键词： gravitational wave detectors and experiments black holes data analysis algorithms and implementation data management

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