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Simulation Analysis of DC Fault Interruption Characteristics of Superconducting Electric Aircraft Propulsion

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1834-1842页

作者： Muhammad Junaid Xiaolong yu Shuzhi Cao Wenqing yu Dongsheng Zuo Jianhua wang School of Electrical Engineering Nanhu CampusChina University of Mining and TechnologyXuzhouJiangsu 221116China Shanghai Dianji University Shanghai 201306China State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong UniversityXi’anShaanxi 710049China

Environmental issues associated with the aviation industry are getting more attention as air traffic *** standards are imposed for fuel consumption and pollution emissions for next-generation *** electrical propulsion aircraft(SEPA)have been seen as an efficient way to achieve this ***-temperature superconducting(HTS)devices are extensively used in the power system to supply enormous *** is distributed to the different loads via a DC distribution ***,it will generate an inrush current over ten times higher than the rated current in short-circuit state,which is very harmful to the ***,it is essential to adopt an appropriate protection *** paper discusses one protection scheme that combines DC vacuum circuit breakers(DC VCB)and resistive superconducting current limiters(RSFCL)for superconducting aircraft *** problems of cost and loss,the auxiliary capacitor is pre-charged by system voltage,and mechanical elements extinguish the ***,combined with RSFCL,the interrupting environment is fully *** limits fault current,and then the VCB breaks this limited current based on creating an artificial current zero(ACZ).The prospective rated power is 8MW,rated voltage and current are 4 kV and 1 kA,*** this paper,we discuss and simulate switching devices that protect *** interrupting performance of the circuit breaker is analysed in the DC short-circuit fault that occurs on the transmission ***,the residual energy consumption of different situations is calculated.A comparison is made between using RSFCL with metal oxide varistor(MOV)and just using *** scheme with RSFCL shows a significant advantage in energy consumption.

关键词： Artificial current zero DC circuit breakers metal oxide varistor RSFCL superconducting electrical propulsion aircraft

A low-profile metamaterial absorber with ultrawideband reflectionless and wide-angular stability

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Defence Technology（防务技术） 2024年第4期34卷 258-268页

作者： Feihong Lin Zhongming Yan Ping wang yu wang Hongcheng Zhou Haoran Lu School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle Ministry of EducationChengdu 610031China China Academy of Launch Vehicle Technology Beijing 100076China

An ultrawideband reflectionless metamaterial absorber(MA)is proposed by replacing the metallic ground with the complementary split-ring resonator(CSRR)*** proposed MA exhibits-10 d B reflectivity spectrum from 1 GHz to 20 GHz,which maintains more than 90%absorption from 1.5 GHz to20 ***,it achieves angle stability for TE and TM polarization at oblique incident angles up to 40°and 65°,*** achieve broadband absorption spectrum,we have adopted a single-layer high-impedance surface(HIS)loaded with a double-layer magnetic material(MM)*** further realize the RCS reduction into a lower frequency range,we have employed the scattering cancellation technology into the traditional metallic ***,we have fabricated a sample exhibiting the 10 d B RCS reduction from 1 GHz to 20 GHz with a thickness of 10 *** and simulation results confirm that the proposed MA exhibits excellent comprehensive performance,making it suitable for many practical applications.

关键词： Metamaterial absorber(MA) Magnetic material(MM) High-impedance surface(HIS) Scattering cancellation technology Ultrawideband Wide-angular stable

Investigation on the vortical structures by the Liutex method in turbulent channels at Re_(τ)=180 with scalloped and triangular riblet control

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Journal of Hydrodynamics 2024年第1期36卷 35-52页

作者： Zhang-dan yu Shang Jiang Hai-dong yu Bi-yu Pang Xin Dong Yi-qian wang School of Mathematical Sciences Soochow UniversitySuzhou215006China Beijing Institute of Astronautical System Engineering Beijing100076China

Riblets are a series of small protrusions formed along the flow direction,which have been extensively studied as a passive turbulent drag reduction *** and numerical simulations have shown that well-designed riblets can significantly reduce drag in turbulent flows,making them highly promising and valuable for various *** this study,we focus on a scalloped riblet,which is designed by smoothly connecting two third-order polynomials,and thus the sharpness of the tip and the curvature of the valley can be well *** conduct direct numerical simulations of turbulent channel with smooth plate,scalloped riblet-mounted and triangular riblet-mounted *** in wall units of W^(+)=20 and height-width ratio ofγ=0.5 are selected for both riblet *** with the smooth plate case,the scalloped riblet case achieves an 8.68%drag reduction,while the triangular riblet case achieves a 4.79%drag *** obtained drag reduction rate of the triangular riblet is consistent with previous experiments and simulations,and the results indicate that the scalloped riblet is more effective in reducing drag and deserves further *** compare turbulent statistics of the scalloped riblet case with those of the triangular riblet *** mean velocity profiles of riblets are similar,but both the Reynolds shear stress and second-order statistics of velocity fluctuations and Liutex are significantly reduced in the scalloped riblets controlled turbulent channel,indicating that the scalloped riblet can more effectively suppress the spanwise and wall-normal turbulent intensity near the *** also compare the pre-multiplied spectra of streamwise velocity and streamwise Liutex component for the three cases to investigate the energy distribution and characteristics of Liutex *** Liutex vortex identification method is also utilized to analyze the instantaneous flow field,which provides insights into the flow field and could be bene

关键词： Liutex vector riblet drag reduction tip sharpness turbulent channel scalloped

Spatial diversion and coordination of flood water for an urban flood control project in Suzhou, China

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Water Science and Engineering 2024年第2期17卷 108-117页

作者： yu Xu You-peng Xu Qiang wang yue-feng wang Chao Gao Department of Geography and Spatial Information Techniques Ningbo UniversityNingbo 315211China State Key Laboratoryof Hydology Water Resources and Hydraulic Enginering Nanjing Hydraulic Research InstitueNanjing 210029China Laboratory of Sustainable Urban Drainage Ningbo UniversityNingbo 31521lChina Schol of Gegraphical and Oceanographic Sciences Nanjing UniversiyNanjing 210023China School of Geography and Tourism Chongqing Normal UniversityChongqing 401331China

Suzhou City,located in the Yangtze River Delta in China,is prone to flooding due to a complex combination of natural factors,including its monsoon climate,low elevation,and tidally influenced position,as well as intensive human *** Large Encirclement Flood Control Project(LEFCP)was launched to cope with serious floods in the urban *** project changed the spatiotemporal pattern of flood processes and caused spatial diversion of floods from the urban area to the outskirts of the ***,this study developed a distributed flood simulation model in order to understand this transition of flood *** results revealed that the LEFCP effectively protected the urban areas from floods,but the present scheduling schemes resulted in the spatial diversion of floods to the outskirts of the *** rainstorm frequencies of 10.0%to 0.5%,the water level differences between two representative water level stations(Miduqiao(MDQ)and Fengqiao(FQ))located inside and outside the LEFCP area,ranged from 0.75 m to 0.24 m and from 1.80 m to 1.58 m,*** addition,the flood safety margin at MDQ and the duration with the water level exceeding the warning water level at FQ ranged from 0.95 m to 0.43 m and from 4 h to 22 h,*** scheduling schemes for the hydraulic facilities of the LEFCP in extreme precipitation cases were developed ac-cording to food simulations under seven scheduling *** helps to regulate the spatial flood diversion caused by the LEFCP during extreme precipitation.

关键词： Urban flooding Urban flood control project Rainstorm fregue ncy Flood simulation model Suzhou City

Exploring pore-scale production characteristics of oil shale after CO_(2) huff‘n’puff in fractured shale with varied permeability

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International Journal of Coal Science & Technology 2024年第1期11卷 194-203页

作者： Tianhan Xu Jian wang yuhao Lu Danling wang Li yu Ye Tian State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina Institute for Carbon Neutrality Southwest Petroleum UniversityChengdu610500SichuanChina Research Institute of Shenzhen Branch of CNOOC(China)Co. LtdShenzhen518000GuangdongChina PetroChina Huabei Oilfield Company Cangzhou062552HebeiChina

Recent studies have indicated that the injection of carbon dioxide(CO_(2))can lead to increased oil recovery in fractured shale reservoirs following natural *** advancements in understanding mass exchange processes in subsurface formations,there remains a knowledge gap concerning the disparities in these processes between the matrix and fractures at the pore scale in formations with varying *** study aims to experimentally investigate the CO_(2) diffusion behaviors and in situ oil recovery through a CO_(2) huff‘n’puff process in the Jimsar shale oil *** achieve this,we designed three matrix-fracture models with different permeabilities(0.074 mD,0.170 mD,and 0.466 mD)and experimented at 30 MPa and 91°*** oil concentration in both the matrix and fracture was monitored using a low-field nuclear magnetic resonance(LF-NMR)technique to quantify in situ oil recovery and elucidate mass-exchange *** results showed that after three cycles of CO_(2) huff‘n’puff,the total recovery degree increased from 30.28%to 34.95%as the matrix permeability of the core samples increased from 0.074 to 0.466 mD,indicating a positive correlation between CO_(2) extraction efficiency and matrix *** similar fracture conditions,the increase in matrix permeability further promoted CO_(2) extraction efficiency during CO_(2) huff‘n’***,the increase in matrix permeability of the core had the greatest effect on the extraction of the first-cycle injection in large pores,which increased from 16.42%to 36.64%.The findings from our research provide valuable insights into the CO_(2) huff‘n’puff effects in different pore sizes following fracturing under varying permeability conditions,shedding light on the mechanisms of CO_(2)-enhanced oil recovery in fractured shale oil reservoirs.

关键词： Shale reservoir Hydraulic fracturing CO_(2)huff‘n’puff NMR Production characteristics

A flame-retardant binder with high polysulfide affinity for safe and stable lithium–sulfur batteries

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Science China Chemistry 2024年第3期67卷 1028-1036页

作者： Guowei yu Guofeng Ye Cheng wang Chenyang wang Zhaoyun wang Pu Hu yu Li Xi-Xi Feng Shuang-Jie Tan Min Yan Sen Xin Zhitian Liu Hubei Key Laboratory of Plasma Chemistry and Advanced Materials Hubei Engineering Technology Research Center of Optoelectronic and New Energy MaterialsSchool of Materials Science and EngineeringWuhan Institute of TechnologyWuhan 430205China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China CAS Key Laboratory of Molecular Nanostructure and Nanotechnology CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular Sciences(BNLMS)Institute of ChemistryChinese Academy of Sciences(CAS)Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Lithium-sulfur(Li-S) batteries have shown promises for the next-generation, high-energy electrochemical storage, yet are hindered by rapid performance decay due to the polysulfide shuttle in the cathode and safety concerns about potential thermal runaway. To address the above challenges, herein, we show a flame-retardant cathode binder that simultaneously improves the electrochemical stability and safety of batteries. The combination of soft and hard segments in the polymer framework of binders allows high flexibility and mechanical strength for adapting to the drastic volume change during the Li(de)intercalation of the S cathode. The binder contains a large number of polar groups, which show the high affinity to polysulfides so that they help to anchor active S species at the cathode. These polar groups also help to regulate and facilitate the Li-ion transport, promoting the kinetics of polysulfide conversion reaction. The binder contains abundant phosphine oxide groups, which, in the case of battery's thermal runaway, decompose and release PO· radicals to quench the combustion reactions and stop the fire. Consequently, Li-S batteries using the new cathode binder show the improved electrochemical performance, including a low-capacity decay of 0.046% per cycle for 800 cycles at 1 C and favorable rate capabilities of up to 3 C. This work offers new insights on the practical realization of high-energy rechargeable batteries with stable storage electrochemistry and high safety.

关键词： lithium–sulfur battery polymer binder polysulfide affinity flame retardancy

Transcriptomic and cellular decoding of scaffolds-induced suture mesenchyme regeneration

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International Journal of Oral Science 2024年第2期16卷 306-321页

作者： Jiayi Wu Feifei Li Peng yu Changhao yu Chuyi Han Yitian wang Fanyuan yu Ling Ye State Key Laboratory of Oral Diseases&National Center for Stomatology&National Clinical Research Center for Oral Diseases&West China Hospital of Stomatology Sichuan UniversityChengduChina State Key Laboratory of Oral Diseases&National Center for Stomatology&National Clinical Research Center for Oral Diseases&Department of Cariology and Endodontics West China Hospital of StomatologySichuan UniversityChengduChina State Key Laboratory of Oral Diseases&National Center for Stomatology&National Clinical Research Center for Oral Diseases&Department of Pediatric Dentistry West China Hospital of StomatologySichuan UniversityChengduChina

Precise orchestration of cell fate determination underlies the success of scaffold-based skeletal *** extensive studies on mineralized parenchymal tissue rebuilding,regenerating and maintaining undifferentiated mesenchyme within calvarial bone remain very challenging with limited advances *** knowledge has evidenced the indispensability of rebuilding suture mesenchymal stem cell niches to avoid severe brain or even systematic *** to date,the absence of promising therapeutic biomaterials/scaffolds *** reason lies in the shortage of fundamental knowledge and methodological evidence to understand the cellular fate regulations of *** address these issues,in this study,we systematically investigated the cellular fate determinations and transcriptomic mechanisms by distinct types of commonly used calvarial *** data elucidated the natural processes without scaffold transplantation and demonstrated how different scaffolds altered in vivo cellular responses.A feasible scaffold,polylactic acid electrospinning membrane(PLA),was next identified to precisely control mesenchymal ingrowth and self-renewal to rebuild non-osteogenic suture-like tissue at the defect center,meanwhile supporting proper osteointegration with defect bony ***,transcriptome analysis and cellular mechanisms underlying the well-orchestrated cell fate determination of PLA were *** study for the first time cellularly decoded the fate regulations of scaffolds in suture-bony composite defect healing,offering clinicians potential choices for regenerating such complicated injuries.

关键词： injuries healing suture

Monitoring shear deformation of sliding zone via fiber Bragg grating and particle image velocimetry

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 231-241页

作者： Deyang wang Honghu Zhu Guyu Zhou Wenzhao yu Baojun wang Wanhuan Zhou School of Earth Sciences and Engineering Nanjing UniversityNanjing210023China Institute of Earth Exploration and Sensing Nanjing UniversityNanjing210023China State Key Laboratory of Internet of Things for Smart City University of MacaoMacaoChina

Monitoring shear deformation of sliding zones is of great significance for understanding the landslide evolution mechanism,in which fiber optic strain sensing has shown great ***,the cor-relation between strain measurements of quasi-distributed fiber Bragg grating(FBG)sensing arrays and shear displacements of surrounding soil remains *** this study,a direct shear model test was conducted to simulate the shear deformation of sliding zones,in which the soil internal deformation was captured using FBG strain sensors and the soil surface deformation was measured by particle image velocimetry(PIV).The test results show that there were two main slip surfaces and two secondary ones,developing a spindle-shaped shear band in the *** formation of the shear band was successfully captured by FBG sensors.A sinusoidal model was proposed to describe the fiber optic cable deformation *** this basis,the shear displacements and shear band widths were calculated by using strain *** work provides important insight into the deduction of soil shear deformation using soil-embedded FBG strain sensors.

关键词： Landslide Shear band Fiber bragg grating(FBG) Particle image velocimetry(PIV) Sinusoidal model Strain‒displacement proportional coefficient

What factors control plant height?

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Journal of Integrative Agriculture 2024年第6期23卷 1803-1824页

作者： Li Miao Xiangyu wang Chao yu Chengyang Ye Yanyan Yan Huasen wang College of Horticulture Qingdao Agricultural UniversityQingdao 266109China Key Laboratory for Quality and Safety Control of Subtropical Fruits and Vegetables College of Horticulture ScienceZhejiang Agriculture and Forestry UniversityHangzhou 311300China

Plant height(PH)is one of the most important components of the plant ideotype,and it affects plant biomass,yield,lodging resistance,and the ability to use mechanized *** many complex pathways controlling plant growth and development remain poorly understood,we are still unable to obtain the most ideal plants solely through breeding *** can be influenced by genotype,plant hormonal regulation,environmental conditions,and interactions with other ***,we comprehensively review the factors influencing PH,including the regulation of PH-related developmental processes,the genetics and QTLs contributing to PH,and the hormone-regulated molecular mechanisms for ***,the symbiotic influence of grafting on PH is discussed,focusing on the molecular regulation of gene expression and ***,we propose strategies for applying recent findings to breeding for better PH,highlight some knowledge gaps,and suggest potential directions for future studies.

关键词： dwarfism plant hormones interaction grafting QTLs phenotyping