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Wave field structure and power coupling features of blue-core helicon plasma driven by various antenna geometries and frequencies

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Chinese Physics B 2024年第3期33卷 480-487页

作者：王超刘佳苌磊卢凌峰张世杰周帆涛 State Key Laboratory of Power Transmission Equipment Technology School of Electrical EngineeringChongqing UniversityChongqing 400044China shanghai institute of space propulsion Shanghai 201112China Southwestern institute of Physics Chengdu 610041China

This paper deals with wave propagation and power coupling in blue-core helicon plasma driven by various antennas and *** is found that compared to non-blue-core mode,for blue-core mode,the wave can propagate in the core region,and it decays sharply outside the *** power absorption is lower and steeper in radius for blue-core *** the effects of antenna geometry for blue-core mode,it shows that half helix antenna yields the strongest wave field and power absorption,while loop antenna yields the ***,near axis,for antennas with m=+1,the wave field increases with axial *** the core region,the wave number approaches to a saturation value at much lower frequency for non-blue-core mode compared to blue-core *** total loading resistance is much lower for blue-core *** findings are valuable to understanding the physics of blue-core helicon discharge and optimizing the experimental performance of blue-core helicon plasma sources for applications such as space propulsion and material treatment.

关键词： helicon plasma helicon wave helicon discharge radio frequency plasma source

Experimental and numerical study on ignition and combustion characteristics of boron-magnesium composite powders

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Particuology 2024年第1期84卷 12-29页

作者： Shuyuan Liu Luyang Han Hongmei Liu Yingkai Song Linlin Liu Songqi Hu Science and Technology on Combustion Internal Flow and Thermo-Structure LaboratoryNorthwestern Polytechnical UniversityXi'an710072China School of Mechanical Engineering and Rail Transit Changzhou UniversityChangzhou213164China shanghai institute of space propulsion Shanghai201112China shanghai Engineering Research Center of space Engine Shanghai201112China

A high-pressure laser ignition and combustion system with adjustable oxidizer gas atmosphere is established to investigate the ignition and combustion characteristics of boron-magnesium(BM)com-posite *** ignition and combustion model of BM powders is established and validated in the present *** results show that increasing water content,O_(2) content and Mg content all result in shorter ignition delay time of BM powders,among which the effect of water content is the most ***,ignition delay time increases as pressure *** combustion time decreases with increasing Mg content and ambient pressure but increases with water *** the increase of O_(2) content,combustion time of BM powders first increases and then decreases,which means a critical O_(2) content exists above which combustion time *** results show that there exists a trade-off between ignition and combustion performance of BM composite powders.

关键词： Boron magnesium powder Laser ignition Ignition and combustion model Reaction mechanism Numerical model

MOF-derived 1D CGO Cathode for Efficient Solid Oxide Electrolysis Cells

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Chemical Research in Chinese Universities 2024年第4期40卷 737-746页

作者： TIAN Jiayu SUN Qi LIU Pei DAI Jiuyi CAI Yezheng XU Miao YE Tian-Nan CHEN Jie-Sheng Frontiers Science Center for Transformative Molecules School of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai200240P.R.China Zhangjiang institute for Advanced Study Shanghai Jiao Tong UniversityShanghai200240P.R.China State Key Laboratory of space Power-sources Shanghai Institute of Space Power-sourcesShanghai200245P.R.China

Solid oxide electrolysis cells(SOECs)provide a promising way for converting renewable energy into chemical ***,NiO/CGO(nickel-gadolinium doped ceria)cermet has shown its excellent properties in ionic and electronic conductivity under reducing ***,we developed a novel 1D NiO/CGO cathode through a cerium metal-organic framework(MOF)derived *** cathode’s 1D nanostructure integrated with a microchannel scaffold facilitates enhanced mass transport,providing vertically aligned pathways for CO_(2)and H_(2)O ***,the 1D framework increases the number of interfacial sites and reduces ion diffusion distances,thereby simplifying electron/ion ***,this advanced cathode achieved a significant breakthrough in SOEC performance,maintaining efficient CO_(2)and H_(2)O electrolysis at an extraordinary current density of 1.41 A/cm^(2)at 1.5 V and excellent stability over 24 h at 850℃.The enhanced performance of this newly developed cathode not only achieves a remarkable 100%improvement compared to those of NiO/CGO cathodes with varying geometrical configurations but also surpasses those of commercial NiO/CGO catalysts by an outstanding 40%when tested under identical *** development of the 1D NiO/CGO enhances the efficiency and durability of ceramic cathodes for CO_(2)and H_(2)O co-electrolysis in SOECs and improves the scalability and effectiveness of SOECs in renewable energy applications.

关键词： Cerium metal-organic framework One-dimensional structure Gadolinium doped ceria CO_(2)activation co-Electrolysis

A non-probabilistic reliability topology optimization method based on aggregation function and matrix multiplication considering buckling response constraints

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 321-336页

作者： Lei WANG Yingge LIU Juxi HU Weimin CHEN Bing HAN institute of Solid Mechanics School of Aeronautic Science and EngineeringBeihang UniversityBeijing 100191China Aircraft and propulsion Laboratory Ningbo Institute of TechnologyBeihang UniversityNingbo 315100Zhejiang ProvinceChina State Key Laboratory of Navigation and Safety Technology Shanghai Ship and Shipping Research InstituteShanghai 200135China National Engineering Research Center of Ship&Shipping Control System Shanghai Ship and Shipping Research InstituteShanghai 200135China

A non-probabilistic reliability topology optimization method is proposed based on the aggregation function and matrix *** expression of the geometric stiffness matrix is derived,the finite element linear buckling analysis is conducted,and the sensitivity solution of the linear buckling factor is *** a specific problem in linear buckling topology optimization,a Heaviside projection function based on the exponential smooth growth is developed to eliminate the gray *** aggregation function method is used to consider the high-order eigenvalues,so as to obtain continuous sensitivity information and refined structural *** cyclic matrix programming,a fast topology optimization method that can be used to efficiently obtain the unit assembly and sensitivity solution is *** maximize the buckling load,under the constraint of the given buckling load,two types of topological optimization columns are *** variable density method is used to achieve the topology optimization solution along with the moving asymptote optimization *** vertex method and the matching point method are used to carry out an uncertainty propagation analysis,and the non-probability reliability topology optimization method considering buckling responses is developed based on the transformation of non-probability reliability indices based on the characteristic ***,the differences in the structural topology optimization under different reliability degrees are illustrated by examples.

关键词： buckling topology optimization aggregation function uncertainty propagation analysis non-probabilistic reliability

Influence of the position relationship between the cathode and magnetic separatrix on the discharge process of a Hall thruster

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Plasma Science and Technology 2024年第1期26卷 74-81页

作者：曹希峰麻洪宁夏国俊刘辉赵方舟王宇航陈巨辉 School of Mechanical and Power Engineering Harbin University of Science and TechnologyHarbin 150001People’s Republic of China shanghai institute of Satellite Engineering Shanghai 20040People’s Republic of China Lab of Plasma propulsion Harbin Institute of TechnologyHarbin 150001People’s Republic of China

Previous studies have shown that there is an obvious coupling relationship between the installation location of the external cathode and the magnetic separatrix in the plume region of a Hall *** this paper,the particle-in-cell simulation method is used to compare the thruster discharge process under the conditions of different position relationships between the cathode and the magnetic *** comparing the distribution of electron conduction,potential,plasma density and other microscopic parameters,we try to explain the formation mechanism of the discharge *** simulation results show that the cathode inside and outside the magnetic separatrix has a significant effect on the distribution of potential and plasma *** the cathode is located on the outer side of the magnetic separatrix,the potential above the plume region is relatively low,and there is a strong potential gradient above the plume *** potential gradient is more conducive to the radial diffusion of ions above the plume,which is the main reason for the strong divergence of the *** distribution of ion density is also consistent with the distribution of *** the cathode is located on the outer side of the magnetic separatrix,the radial diffusion of ions in the plume region is ***,by comparing the results of electron conduction,it is found that the traiectories of electrons emitted from the cathode are significantly different between the inner and outer sides of the magnetic *** is mainly because the electrons are affected by the magnetic mirror effect of the magnetic tip,which makes it difficult for the electrons to move across the magnetic *** is the main reason for the difference in potential *** this paper,the simulation results of macroscopic parameters under several conditions are also compared,and they are consistent with the experimental *** cathode is located on the inner side of the ma

关键词： Hall thruster cathode magnetic separatrix

An integrative mathematical model of microwave ion thruster for mHz-frequency thrust noise analysis

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Chinese Journal of Aeronautics 2024年第4期37卷 121-136页

作者： Xiang NIU Hui LIU Daren YU Plasma propulsion Laboratory Harbin Institute of TechnologyHarbin 150001China

Many high-precision space missions need thrusters to produce thrust with low noise to compensate for disturbances and ensure satellite platform stability. Microwave ion thruster is characterized with a wide thrust range and potential for these missions. A cost-effective and accurate mathematical model is crucial for mHz-frequency thrust noise analysis and feedback controller design. The Particle-In-Cell(PIC) and global models are two common simulation tools. The PIC model is characterized with high accuracy but huge computation cost, which is difficult to analyze long-time performance characteristics. Now, the global model is only used for the discharge chamber with low accuracy and cannot reflect ion extraction properties. In this paper, an integrative mathematical model is built for a 1-cm microwave ion thruster and can reflect ion beamlet divergence and impingement on the Accelerator Grid(AG). Simulation results show good agreement with experiments at 0.06 sccm. However, the model demonstrates worse consistency with experiments when the flux increases to 0.1 sccm, which may be because the influence of neutral gas on the Electron Cyclotron Resonance(ECR) is not considered in the model. A long-time(1000 s) simulation is conducted with this model under 35 μN. It takes 3 hrs, and the thrust noise reaches 1 μN/Hz^(0.5) at 1 mHz.

关键词： Electric propulsion Microwave ion thruster Integrative model Sheath property Ion beamlet divergence Thrust noise Plasma

Active Magnetic Compensation Based on Parametric Resonance Magnetometer

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Journal of shanghai Jiaotong university(Science) 2024年第2期29卷 280-289页

作者：郭阳李绍良黄艺明骆曼箬刘华 School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China shanghai institute of spacefight Control Technology Shanghai Key Laboratory of Space Intelligent Control TechnologyShanghai Engineer Research Center of InertiaShanghai 201109China

Based on the parametric resonance magnetometer(PRM)theory,this paper establishes an experimen-tal system of *** experimental results are consistent with the theoretical predictions.A PRM has been developed with sensitivity of 0.5 pT/Hz^(1/2),which can detect the magnitude of residual magnetic field;furthermore,a proportion-integration-differentiation(PID)closed-loop magnetic compensation system of the residual magnetic field also has been *** with open-loop compensation,the PID closed-loop compensation reduces the average value of the residual magnetic field in the z-axis direction from 0.0244nT to-0.0023nT,and the mean-square error from 0.2083 nT to 0.0691 *** the same way,the average value of the residual magnetic field in the y-axis direction is reduced from 0.0816nT to-0.0042nT,and the mean-square error from 0.1316nT to 0.0461 *** magnitude of residual magnetic fields in both directions is decreased to the order of picotesla(pT).In addition,based on the signal waveforms of the magnetometer,a method of verifying the effect of magnetic compensation is proposed.

关键词： magnetometer parametric resonance nuclear magnetic resonance gyroscope magnetic compensa-tion proportion-integration-differentiation(PID)

Metal-free two-dimensional phosphorene-based electrocatalyst with covalent P-N heterointerfacial reconstruction for electrolyte-lean lithium-sulfur batteries

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Carbon Energy 2024年第5期6卷 175-185页

作者： Jiangqi Zhou Chengyong Shu Jiawu Cui Chengxin Peng Yong Liu Weibo Hua Laura Simonelli Yuping Wu Shi Xue Dou Wei Tang School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'anChina School of Materials Science and Engineering University of Shanghai for Science and TechnologyShanghaiChina State Key Laboratory of space Power-Sources Technology Shanghai Institute of Space Power-SourcesShanghaiChina CELLS-ALBA Synchrotron BarcelonaSpain School of Energy and Environment Southeast UniversityNanjingChina

The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox ***-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical *** resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle ***,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass ***,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding *** work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries.

关键词： black phosphorus electronic structure high sulfur loading interfacial covalent bonds lean electrolyte

Decoupling of temporal/spatial broadening effects in Doppler wind LiDAR by 2D spectral analysis

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Chinese Physics B 2024年第3期33卷 447-452页

作者：刘珍张云鹏竹孝鹏刘继桥毕德仓陈卫标 space Laser Engineering Department Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Pulse echo accumulation is commonly employed in coherent Doppler wind LiDAR(light detection and ranging)under the assumption of steady ***,the measured spectral data are analyzed in the time dimension and frequency dimension to cope with the temporal wind shear and achieve the optimal accumulation time.A hardware-efficient algorithm combining the interpolation and cross-correlation is used to enhance the wind retrieval accuracy by reducing the frequency sampling interval and then reduce the spectral width calculation ***,the temporal broadening effect and spatial broadening effect are decoupled according to the strategy we developed.

关键词： Doppler wind LiDAR spectral analysis hardware efficiency spectrum broadening effects