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Power transfer efficiency in an air-breathing radio frequency ion thruster

Chinese Physics B 2024年第7期33卷 430-438页

作者：黄高煌李宏高飞王友年 key laboratory of materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China College of physical science and technology Dalian UniversityDalian 116622China

Due to a series of challenges such as low-orbit maintenance of satellites, the air-breathing electric propulsion has got widespread attention. Commonly, the radio frequency ion thruster is favored by low-orbit missions due to its high specific impulse and efficiency. In this paper, the power transfer efficiency of the radio frequency ion thruster with different gas compositions is studied experimentally, which is obtained by measuring the radio frequency power and current of the antenna coil with and without discharge operation. The results show that increasing the turns of antenna coils can effectively improve the radio frequency power transfer efficiency, which is due to the improvement of Q factor. In pure N_2 discharge,with the increase of radio frequency power, the radio frequency power transfer efficiency first rises rapidly and then exhibits a less steep increasing trend. The radio frequency power transfer efficiency increases with the increase of gas pressure at relatively high power, while declines rapidly at relatively low power. In N_2/O_2 discharge, increasing the N_2 content at high power can improve the radio frequency power transfer efficiency, but the opposite was observed at low power. In order to give a better understanding of these trends, an analytic solution in limit cases is utilized, and a Langmuir probe was employed to measure the electron density. It is found that the evolution of radio frequency power transfer efficiency can be well explained by the variation of plasma resistance, which is related to the electron density and the effective electron collision frequency.

关键词： radio frequency ion thruster inductively coupled plasma power transfer efficiency analytic solution

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Palladium Complexes with N,O-Bidentate Ligands Based on N-Oxide Units from Cyclic Secondary Amines:Synthesis and Catalytic Application in Mizoroki-Heck Reaction

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Chinese Journal of Chemistry 2024年第3期42卷 294-300页

作者： Xuefeng Jia Yanyan Wen Changhui He Xianqiang Huang key laboratory of magnetic Molecules and magnetic Information materials of ministry of education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuanShanxi030032 China Shandong Provincial key laboratory of Chemical Energy Storage and Novel Cell technology School of Chemistry & Chemical EngineeringLiaocheng UniversityLiaochengShandong252059 China

Palladium-catalyzed Mizoroki-Heck reaction is a powerful and efficient method for construction of Csp2–Csp2 bonds.Herein,four palladium complexes(I—IV)with N,O-bidentate ligands(L1—L4)based on N-oxide units from cyclic secondary amines were easily synthesized and successfully applied in Mizoroki-Heck reaction of aryl bromides with electron-deficient olefins.X-ray diffraction analyses indicated the palladium(II)atom of II took the distorted square planar geometry and was four-coordinated by nitrogen and oxygen atoms from two ligands(L2).Two free chloride ions were presented as counter anions in complex II.But the palladium(II)center of IV was coordinated by nitrogen and oxygen atoms from one ligand(L4)as well as two chlorine atoms,which exhibited the nearly square-planar geometry.The study on catalytic properties of palladium complexes revealed that complex II exhibited high activity superior to the other complexes.The coupling reactions of a series of aryl bromides and olefin derivatives proceeded in the presence of 2—5 mol%palladium complex II,giving the desired products in good to excellent yields.The advantages of this method such as good compatibility of functional groups,high yields,and short reaction times made it more attractive for constructing Csp2–Csp2 bonds in the synthesis of functional molecules and materials.

关键词： Palladium complexes N,O-Bidentate ligands N-Oxide units Mizoroki-Heck reaction Aryl bromide Electron-deficient olefins C—C coupling Homogeneous catalysis Substituent effects

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Interfacial engineering of the layered oxide cathode materials for sodium-ion battery

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Nano Research 2024年第3期17卷 1441-1464页

作者： Quanqing Zhao Ruru Wang Ming Gao Faheem KButt Jianfeng Jia Haishun Wu Youqi Zhu key laboratory of magnetic Molecules and magnetic Information materials of ministry of education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuan 030032China Metals and Chemistry Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China Department of Physics Division of Science and TechnologyUniversity of EducationLahore 54770Pakistan Research Center of materials science Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green ApplicationsBeijing Institute of TechnologyBeijing 100081China

The layered metal oxides are reviewed as the hopeful cathode materials for high-performance sodium-ion batteries(SIBs)due to their large theoretical capacity,favorable two-dimensional(2D)ion diffusion channel,and simple manipuility.However,their cycling stability,rate capability,and thermal stability are still significantly concerned and highlighted before further practical application.The chemical,mechanical and electrochemical stability of the cathode–electrolyte interfaces upon cycling is of great significance.Herein,the unique structural and electrochemical properties of the layered oxide cathode materials for SIB are reviewed.The mechanism of bulk/surface degradation induced by oxygen evolution,phase transition,microcrack,and electrolyte decomposition is thoroughly understood.Furthermore,the interfacial engineering to construct stable interface through various effective methods is fully discussed.The future outlook and challenges for interfacial engineering in this filed are also summarized.This review should shed light on the rational design and construct of robust interface for applications of superior layered oxide cathodes in SIB and may suggest future research directions.

关键词： interfacial engineering sodium-ion battery layered oxide electrolyte interface

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Selective oxygen electroreduction to hydrogen peroxide in acidic media:The superiority of single-atom catalysts

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Nano Research 2024年第6期17卷 4668-4681页

作者： Ergui Luo Tongtong Yang Jingyi Liang Yuhong Chang Junming Zhang Tianjun Hu Junjie Ge Jianfeng Jia key laboratory of magnetic Molecules and magnetic Information materials of ministry of education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuan 030032China school of Chemistry and materials science University of Science and Technology of ChinaHefei 230026China State key laboratory of Electroanalytic Chemistry Jilin Province Key Laboratory of Low Carbon Chemistry PowerChangchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Two-electron oxygen reduction reaction(2e-ORR)provides an environmentally friendly direction for the on-site production of hydrogen peroxide(H_(2)O_(2)).Central to this technology is the exploitation of efficient,economical,and safe 2e-ORR electrocatalysts.This overview starts with the fundamental chemistry of ORR to highlight the decisive role of adsorbing intermediates on the reaction pathway and activity,followed by a comprehensive survey of the tuning strategies to favor 2e-ORR on traditional precious metals.The latest achievements in designing efficient and selective precious-metal-based single-atom catalysts(SACs)and metal-nitrogen-carbon(M-Nx/C)catalysts,from the aspects of material synthesis,theoretical calculations,and mass transport promotion,are systematically summarized.Brief introductions on the evaluation metrics for 2e-ORR catalysts and the primary reactor designs for cathodic H_(2)O_(2)synthesis are also included.We conclude this review with an outlook on the challenges and direction of efforts to advance electrocatalytic 2e-ORR into realistic H_(2)O_(2)production.

关键词： oxygen reduction reaction H_(2)O_(2)production single-atom catalysts selectivity

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Phase-engineering modulation of Mn-based oxide cathode for constructing super-stable sodium storage

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Journal of Energy Chemistry 2024年第1期88卷 421-427,I0010页

作者： Quanqing Zhao Ruru Wang Ming Gao Bolin Liu Jianfeng Jia Haishun Wu Youqi Zhu Chuanbao Cao key laboratory of magnetic Molecules and magnetic Information materials of ministry of education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuan 030032ShanxiChina Metals and Chemistry Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China Research Center of materials science Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green ApplicationsBeijing Institute of TechnologyBeijing 100081China

The Mn-based oxide cathode with enriched crystal phase structure and component diversity can provide the excellent chemistry structure for Na-ion batteries.Nevertheless,the broad application prospect is obstructed by the sluggish Na^(+)kinetics and the phase transitions upon cycling.Herein,we establish the thermodynamically stable phase diagram of various Mn-based oxide composites precisely controlled by sodium content tailoring strategy coupling with co-doping and solid-state reaction.The chemical environment of the P2/P'3 and P2/P3 biphasic composites indicate that the charge compensation mechanism stems from the cooperative contribution of anions and cations.Benefiting from the no phase transition to scavenge the structure strain,P2/P'3 electrode can deliver long cycling stability(capacity retention of 73.8%after 1000 cycles at 10 C)and outstanding rate properties(the discharge capacity of 84.08 mA h g^(-1)at 20 C)than P2/P3 electrode.Furthermore,the DFT calculation demonstrates that the introducing novel P'3 phase can significantly regulate the Na^(+)reaction dynamics and modify the local electron configuration of Mn.The effective phase engineering can provide a reference for designing other high-performance electrode materials for Na-ion batteries.

关键词： Sodium ion battery Oxide cathode Phase engineering Phase diagram Na~+kinetic

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Pushing the high-k scalability limit with a superparaelectric gate layer

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Journal of Advanced Ceramics 2024年第4期13卷 539-547页

作者： Kun Wang Chao Liu Yuan Zhang Fuyu Lv Jun Ouyang Houbing Huang Rui-Long Yang Yu-Yao Zhao Hongbo Cheng Hanfei Zhu Xiaoming Shi Yun Tian Institute of Advanced Energy materials and Chemistry Jinan Engineering Laboratory for Multi-scale Functional MaterialsSchool of Chemistry and Chemical EngineeringQilu University of Technology(Shandong Academy of Sciences)Jinan 250353China key laboratory for Liquid-Solid Structure Evolution and Processing of materials(ministry of education) School of Materials Science and EngineeringShandong UniversityJinan 250061China China Tobacco Shandong Industrial Co. Ltd.Jinan 250104China Department of materials science and Engineering Southern University of Science and TechnologyShenzhen 518055China key laboratory of key Film materials&Application for Equipments(Hunan Province) School of Material Sciences and EngineeringXiangtan UniversityXiangtan 411105China Advanced Research Institute of Multidisciplinary science and School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China key laboratory of magnetic Molecules and magnetic Information materials of ministry of education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuan 030032China

To meet the expectation set by Moore’s law on transistors,the search for thickness-scalable high dielectric constant(k)gate layers has become an emergent research frontier.Previous investigations have failed to solve the“polarizability–scalability–insulation robustness”trilemma.In this work,we show that this trilemma can be solved by using a gate layer of a high k ferroelectric oxide in its superparaelectric(SPE)state.In the SPE,its polar order becomes local and is dispersed in an amorphous matrix with a crystalline size down to a few nanometers,leading to an excellent dimensional scalability and a good field-stability of the k value.As an example,a stable high k value(37±3)is shown in ultrathin SPE films of(Ba_(0.95),Sr_(0.05))(Zr_(0.2),Ti_(0.8))O_(3)deposited on LaNiO_(3)-buffered Pt/Ti/SiO_(2)/(100)Si down to a 4 nm thickness,leading to a small equivalent oxide thickness of~0.46 nm.The aforementioned characteristic microstructure endows the SPE film a high breakdown strength(~10.5 MV·cm^(−1)for the 4 nm film),and hence ensures a low leakage current for the operation of the complementary metal oxide semiconductor(CMOS)gate.Lastly,a high electrical fatigue resistance is displayed by the SPE films.These results reveal a great potential of superparaelectric materials as gate dielectrics in the next-generation microelectronics.

关键词： high-k transistors Moore's law superparaelectric insulation robustness

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Open-Shell Oligomers and Polymers: Theory, Characterization Methods, Molecular Design, and Applications

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Chinese Journal of Polymer science 2024年第4期42卷 417-436页

作者： Xue-Qing Wang Cheng Song Ting Lei key laboratory of Polymer Chemistry and Physics(ministry of education) School of Materials Science and EngineeringPeking UniversityBeijing100871China

Open-shell oligomers and polymers have exhibited intriguing electronic and magnetic properties, making them highly desirable for a wide range of applications, including ambipolar organic field-effect transistors (OFETs), photodetectors, organic thermoelectrics, and spintronics. Although open-shell ground states have been observed in certain small molecules and doped organic semiconductors, the exploration of open-shell ground-state conjugated polymers is still limited, and the strategies for designing these polymers remain obscure. This review aims to briefly introduce the theory and characterization methods of open-shell conjugated polymers, along with an overview of recent progress and applications. The objective is to stimulate further advancements and investigations in this promising area by shedding light on the potential of open-shell conjugated polymers and the challenges that lie ahead.

关键词： Conjugated polymers Open-shell molecules High-spin ground state Donor-acceptor(D-A)polymers Optoelectronic and magnetic properties

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Structural Engineering of Hierarchical magnetic/Carbon Nanocomposites via In Situ Growth for High-Efficient Electromagnetic Wave Absorption

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Nano-Micro Letters 2024年第9期16卷 262-278页

作者： Xianyuan Liu Jinman Zhou Ying Xue Xianyong Lu key laboratory of Bio‑Inspired Smart Interfacial science and technology of ministry of education School of ChemistryBeihang UniversityBeijing 100191People’s Republic of China

materials exhibiting high-performance electromagnetic wave absorption have garnered considerable scientific and technological attention,yet encounter significant challenges.Developing new materials and innovative structural design concepts is crucial for expanding the application field of electromagnetic wave absorption.Particularly,hierarchical structure engineering has emerged as a promising approach to enhance the physical and chemical properties of materials,providing immense potential for creating versatile electromagnetic wave absorption materials.Herein,an exceptional multi-dimensional hierarchical structure was meticulously devised,unleashing the full microwave attenuation capabilities through in situ growth,selfreduction,and multi-heterogeneous interface integration.The hierarchical structure features a three-dimensional carbon framework,where magnetic nanoparticles grow in situ on the carbon skeleton,creating a necklace-like structure.Furthermore,magnetic nanosheets assemble within this framework.Enhanced impedance matching was achieved by precisely adjusting component proportions,and intelligent integration of diverse interfaces bolstered dielectric polarization.The obtain Fe_(3)O_(4)-Fe nanoparticles/carbon nanofibers/Al-Fe_(3)O_(4)-Fe nanosheets composites demonstrated outstanding performance with a minimum reflection loss(RLmin)value of−59.3 dB and an effective absorption bandwidth(RL≤−10 dB)extending up to 5.6 GHz at 2.2 mm.These notable accomplishments offer fresh insights into the precision design of high-efficient electromagnetic wave absorption materials.

关键词： Electromagnetic wave absorption Hierarchical structure In situ growth Self-reduction

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Revealing the atomic mechanism of diamond–iron interfacial reaction

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Carbon Energy 2024年第3期6卷 255-263页

作者： Yalun Ku Kun Xu Longbin Yan Kuikui Zhang Dongsheng Song Xing Li Shunfang Li Shaobo Cheng Chongxin Shan Henan key laboratory of Diamond Optoelectronic materials and Devices Key Laboratory of Material PhysicsMinistry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhouChina Department of Mechanical Engineering Stanford UniversityStanfordCaliforniaUSA Information materials and Intelligent Sensing laboratory of Anhui Province Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationInstitutes of Physical Science and Information TechnologyAnhui UniversityHefeiChina Institute of Quantum materials and Physics Henan Academy of SciencesZhengzhouChina

Diamond,with ultrahigh hardness,high wear resistance,high thermal conductivity,and so forth,has attracted worldwide attention.However,researchers found emergent reactions at the interfaces between diamond and ferrous materials,which significantly affects the performance of diamond-based devices.Herein,combing experiments and theoretical calculations,taking diamond–iron(Fe)interface as a prototype,the counter-diffusion mechanism of Fe/carbon atoms has been established.Surprisingly,it is identified that Fe and diamond first form a coherent interface,and then Fe atoms diffuse into diamond and prefer the carbon vacancies sites.Meanwhile,the relaxed carbon atoms diffuse into the Fe lattice,forming Fe_(3)C.Moreover,graphite is observed at the Fe_(3)C surface when Fe_(3)C is over-saturated by carbon atoms.The present findings are expected to offer new insights into the atomic mechanism for diamondferrous material's interfacial reactions,benefiting diamond-based device applications.

关键词： coherent interface counter-diffusion diamond iron phase transition

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Magnetocaloric effect and phase transition critical behavior of La0.75Sr0.25Mn0.9Co0.1O3 compound synthesized under the high pressure

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Tungsten 2024年第3期6卷 621-632页

作者： Jing Zhao Lei Gao Jian-Jun Zhao Wei Wei Hui-Qin Yun Ru Xing Huai-Jin Ma Xiang Jin Luo-Meng Chao school of physical science and technology Key Laboratory of Magnetism and Magnetic Materials for Higher Education in Inner Mongolia Autonomous Region Baotou Teachers' College National key laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization Baotou Research Institute of Rare Earths school of Physics and Electronic Information Inner Mongolia Normal University College of science Inner Mongolia University of Science and Technology

In this study,a novel method is proposed for producing perovskite rare-earth manganese oxide magnetic refrigeration materials that exhibit superior properties compared to similar materials.The maximum magnetic entropy change values for this sample are 1.44 and 3.75 J·kg-1·K-1for magnetic fields of 2 and 7 T,respectively.Additionally,its relative cooling power has been calculated to be 101.96 and 404.78 J·kg-1,indicating good performance.Both results were obtained using the sample synthesized under a pressure of 4 GPa,and the sample has undergone a second phase transition.The critical behavior of the sample fits well with the mean field model.For different magnetic fields,there is a significant overlap between the values of the maximum magnetic entropy change and the temperature-averaged entropy change,indicating that the refrigeration performance of the sample after high pressure can approach its maximum capability.

关键词： High-pressure synthesis Magnetocaloric effect Relative cooling power magnetic phase transition

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