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Study on Double Resonant Performance of Air-core Spiral Tesla Transformer Applied in Repetitive Pulsed Operation

IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION 2015年第4期22卷 1916-1923页

作者： Lee Li Ma Ning Chen Dehuai Liu Lun Kang Qiang Li Mingjia Cheng Yong Pan Yuan Huazhong Univ Sci & Technol State Key Lab Adv Elect Engn & Technol Sch Elect & Elect Engn Wuhan 430074 Peoples R China China Acad Engn Phys Mianyang 621900 Peoples R China Shanghai Jiao Tong Univ IFSA Collaborat Innovat Ctr Shanghai 200240 Peoples R China

Air-core Tesla transformer combined with semiconductor devices can generate repetitive high-voltage pulses effectively. Air-core Tesla transformer of spiral type is suitable for repetitive operation since its primary voltage is relatively low. Based on the double resonance circuit of air-core Tesla transformer, the expressions of secondary voltage, primary current, and the maximum rise-rate of primary current are deduced. The effects of tuning characteristic on the output voltage and energy efficiency are simulated, and further verified by experiments. An air-core Tesla transformer prototype of spiral type is developed. To achieve repetitive operation, a resonant charging and discharging circuit based on air-core Tesla transformer is designed. The repetitive system based on this prototype can generate microsecond pulses with an average peak voltage of -140 kV at 300 Hz repetition rate. In repetitive mode, the tuning ratio is recommended to range in 1.0-2.0 to achieve high energy efficiency. The output voltage could be higher by increasing the charging voltage or tuning ratio.

关键词： Air-core Tesla transformer resonant charging tuning ratio secondary voltage energy efficiency

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The Event Horizon Telescope Image of the Quasar NRAO 530

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Astrophysical Journal 2023年第2期943卷 170-170页

作者： Jorstad, Svetlana Wielgus, Maciek Lico, Rocco Issaoun, Sara Broderick, Avery E. Pesce, Dominic W. Liu, Jun Zhao, Guang-Yao Krichbaum, Thomas P. Blackburn, Lindy Chan, Chi-Kwan Janssen, Michael Ramakrishnan, Venkatessh Akiyama, Kazunori Alberdi, Antxon Algaba, Juan Carlos Bouman, Katherine L. Cho, Ilje Fuentes, Antonio Gómez, José L. Gurwell, Mark Johnson, Michael D. Kim, Jae-Young Lu, Ru-Sen Martí-Vidal, Iván Moscibrodzka, Monika Pötzl, Felix M. Traianou, Efthalia van Bemmel, Ilse Alef, Walter Anantua, Richard Asada, Keiichi Azulay, Rebecca Bach, Uwe Baczko, Anne-Kathrin Ball, David Baloković, Mislav Barrett, John Bauböck, Michi Benson, Bradford A. Bintley, Dan Blundell, Raymond Bower, Geoffrey C. Boyce, Hope Bremer, Michael Brinkerink, Christiaan D. Brissenden, Roger Britzen, Silke Broguiere, Dominique Bronzwaer, Thomas Bustamante, Sandra Byun, Do-Young Carlstrom, John E. Ceccobello, Chiara Chael, Andrew Chatterjee, Koushik Chatterjee, Shami Chen, Ming-Tang Chen, Yongjun Cheng, Xiaopeng Christian, Pierre Conroy, Nicholas S. Conway, John E. Cordes, James M. Crawford, Thomas M. Crew, Geoffrey B. Cruz-Osorio, Alejandro Cui, Yuzhu Davelaar, Jordy De Laurentis, Mariafelicia Deane, Roger Dempsey, Jessica Desvignes, Gregory Dexter, Jason Dhruv, Vedant Doeleman, Sheperd S. Dougal, Sean Dzib, Sergio A. Eatough, Ralph P. Emami, Razieh Falcke, Heino Farah, Joseph Fish, Vincent L. Fomalont, Ed Ford, H. Alyson Fraga-Encinas, Raquel Freeman, William T. Friberg, Per Fromm, Christian M. Galison, Peter Gammie, Charles F. García, Roberto Gentaz, Olivier Georgiev, Boris Goddi, Ciriaco Gold, Roman Gómez-Ruiz, Arturo I. Gu, Minfeng Hada, Kazuhiro Haggard, Daryl Haworth, Kari Hecht, Michael H. Hesper, Ronald Heumann, Dirk Ho, Luis C. Ho, Paul Honma, Mareki Huang, Chih-Wei L. Huang, Lei Hughes, David H. Ikeda, Shiro Impellizzeri, C.M. Violette Inoue, Makoto James, David J. Jannuzi, Buell T. Jeter, Britton Jiang, Wu Jiménez-Rosales, Alejandra Joshi, Abhishek V. Jung, Taehyun Karami, Mansour Karuppusamy, Ramesh Kawashima, Tomohisa Keati Institute for Astrophysical Research Boston University 725 Commonwealth Avenue Boston 02215 MA United States Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 Bonn D-53121 Germany Instituto de Astrofísica de Andalucía-CSIC Glorieta de la Astronomía s/n Granada E-18008 Spain INAF-Istituto di Radioastronomia Via P. Gobetti 101 Bologna I-40129 Italy Center for Astrophysics Harvard & Smithsonian 60 Garden Street Cambridge 02138 MA United States NASA Hubble Fellowship Program Perimeter Institute for Theoretical Physics 31 Caroline Street North Waterloo N2L 2Y5 ON Canada Department of Physics and Astronomy University of Waterloo 200 University Avenue West Waterloo N2L 3G1 ON Canada Waterloo Centre for Astrophysics University of Waterloo Waterloo N2L 3G1 ON Canada Harvard University 20 Garden Street Cambridge 02138 MA United States Steward Observatory Department of Astronomy University of Arizona 933 N. Cherry Avenue Tucson 85721 AZ United States Data Science Institute University of Arizona 1230 N. Cherry Avenue Tucson 85721 AZ United States Program in Applied Mathematics University of Arizona 617 N. Santa Rita Tucson 85721 AZ United States Astronomy Department Universidad de Concepción Casilla 160-C Concepción Chile Finnish Centre for Astronomy with ESO University of Turku FI-20014 Finland Aalto University Metsähovi Radio Observatory Metsähovintie 114 Kylmälä FI-02540 Finland Massachusetts Institute of Technology Haystack Observatory 99 Millstone Road Westford 01886 MA United States National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo 181-8588 Japan Department of Physics Faculty of Science Universiti Malaya Kuala Lumpur 50603 Malaysia California Institute of Technology 1200 East California Boulevard Pasadena 91125 CA United States Department of Astronomy and Atmospheric Sciences Kyungpook National University Daegu 702-701 South Korea Shanghai Astronomical Observatory Chinese Academy of Sciences 80

We report on the observations of the quasar NRAO 530 with the Event Horizon Telescope (EHT) on 2017 April 5−7, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A*. At z = 0.902, this is the most distant object imaged by the EHT so far. We reconstruct the first images of the source at 230 GHz, at an unprecedented angular resolution of ∼20 μas, both in total intensity and in linear polarization (LP). We do not detect source variability, allowing us to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which we associate with the core. The feature is linearly polarized, with a fractional polarization of ∼5%-8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle ∼ −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field. Future EHT observations will probe the variability of the jet structure on microarcsecond scales, while simultaneous multiwavelength monitoring will provide insight into the high-energy emission origin. © 2023. The Author(s). Published by the American Astronomical Society.

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Mesoscale electric fluctuations interacting with zonal flows, magnetic fluctuations and turbulence

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NUCLEAR FUSION 2017年第7期57卷 1-1页

作者： Zhao, K. J. Nagashima, Y. Diamond, P. H. Dong, J. Q. Itoh, K. Itoh, S. -I. Yan, L. W. Cheng, J. Fujisawa, A. Inagaki, S. Kosuga, Y. Sasaki, M. Huang, Z. H. Yu, D. L. Li, Q. Ji, X. Q. Song, X. M. Huang, Y. Liu, Yi Yang, Q. W. Ding, X. T. Duan, X. R. Southwestern Inst Phys POB 432 Chengdu 610041 Peoples R China Kyushu Univ Res Inst Appl Mech Kasuga Koen 6-1 Kasuga Fukuoka 8168580 Japan Univ Calif San Diego Ctr Momentum Transport & Flow Org San Diego CA 92093 USA Zhejiang Univ Inst Fus Theory & Simulat Hangzhou 310027 Zhejiang Peoples R China Natl Inst Fus Sci Toki Gifu 5095292 Japan Chubu Univ Inst Sci & Technol Res Kasugai Aichi 4878501 Japan

New mesoscale electric fluctuations (MSEFs) are identified in the edge plasmas of the HL-2A tokamak using multiple Langmuir probe arrays. The MSEFs, resulting from the synchronization and having components of dominant geodesic acoustic mode (GAM) and m/n = 6/2 potential fluctuations, are found at the same frequency as that of the magnetic fluctuations of m/n = 6/2 (m and n are poloidal and toroidal mode numbers, respectively). The temporal evolutions of the MSEFs and the magnetic fluctuations clearly show the frequency entrainment and the phase lock between the GAM and the m/n = 6/2 magnetic fluctuations. The results indicate that GAMs and magnetic fluctuations can transfer energy through nonlinear synchronization. The nonlinear coupling analyses show that the MSEFs couple to turbulence and low frequency zonal flows (LFZFs). This suggests that the MSEFs may contribute to the LFZF formation, reduction of turbulence level, and thus confinement regime transitions. The analysis of the envelope modulation demonstrates that both the MSEFs and the LFZFs modulate the turbulence while the MSEFs are modulated by the LFZFs.

关键词： magnetic fluctuations turbulence zonal flows mesoscale electric fluctuations nonlinear synchronization

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Implementation and Optimization of AES Algorithm on the Sunway TaihuLight 17

Implementation and Optimization of AES Algorithm on the Sunw...

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17th International Conference on Parallel and Distributed Computing, Applications and Technologies (PDCAT)

作者： Chen, Yuedan Li, Kenli Fei, Xiongwei Quan, Zhe Li, Keqin Hunan Univ Coll Comp Sci & Elect Engn Changsha 410082 Hunan Peoples R China Natl Supercomp Ctr Changsha Changsha 410082 Hunan Peoples R China SUNY Coll New Paltz Dept Comp Sci New Paltz NY 12561 USA

ISBN: (纸本)9781509050819

With the rapid development of information technology, the security of massive amounts of digital data has attracted huge attention in recent years. In this paper, we provide an efficient parallel implementation of the advanced Encryption Standard (AES) algorithm, a widely used symmetrical block encryption algorithm, based on the Sunway TaihuLight. The Sunway TaihuLight is a China's independently developed heterogeneous supercomputer with peak performance over 100 PFlops. We also optimize the parallel implementation of the AES algorithm based on the Sunway TaihuLight to achieve more optimized performance. The optimization of the parallel AES algorithm in a single SW26010 node is provided. Specifically, we expand the scale to 1024 nodes and achieve the throughput of about 63.91 GB/s (511.28 Gbits/s). Our parallel implementation of the AES algorithm has great parallel scalability and the speedup ratio can be very high with the number of nodes increasing.

关键词： advanced Encryption Standard (AES) Parallelism the Sunway TaihuLight Many-core Speedup Through-put Parallel Scalability

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EFFECT OF OXIDATION ON WETTING BEHAVIOR BETWEEN SILICON AND SILICON CARBIDE 145

EFFECT OF OXIDATION ON WETTING BEHAVIOR BETWEEN SILICON AND ...

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7th International Symposium on High-Temperature Metallurgical Processing held during TMS 145th Annual Meeting and Exhibition

作者： Li, Yaqiong Zhang, Lifeng Benouahmane, Zineb Univ Sci & Technol Beijing Sch Met & Ecol Engn Beijing 100083 Peoples R China

ISBN: (纸本)9781119274643;9781119225751

Experimental oxidation tests at high temperature (1000-1200 degrees C) on SiC samples have been respectively performed under wet and dry air atmosphere for different holding times. The thickness of thermally grown oxide was experimentally measured by DEKTAK Stylus Profilometry. The results showed that the oxidation rate was increased with temperature and holding time, corresponding to a passive oxidation regime which led to the formation of SiO2 layer. The sessile drop method was employed in order to measure the contact angles between Si and SiC at high temperature. Contact angle can be varied from 39.6 degrees to 75.6 degrees by controlling the atmosphere. The deoxidation of the oxide layer and infiltration of liquid silicon caused decrease in the contact angle.

关键词： Oxidation Wettability Silicon SiC

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INFLUENCE OF OXIDATION ON CONTACT ANGLE BETWEEN LIQUID ALUMINUM AND Al₂O₃ 145

INFLUENCE OF OXIDATION ON CONTACT ANGLE BETWEEN LIQUID ALUMI...

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Symposium on Light Metals held during 145th The-Minerals-Metals-and-Materials-Society Annual Meeting and Exhibition

作者： Shen, Ping Zhang, Lifeng Wang, Yi Univ Sci & Technol Beijing Sch Met & Ecol Engn Beijing 100083 Peoples R China

ISBN: (纸本)9781119274780;9781119225799

Aluminum can be easily oxidized at high temperature so that it is difficult to accurately measure the contact angle between the liquid aluminum and Al2O3 substrate. In the current study, the measurement of the contact angle between liquid aluminum and Al2O3 was performed under Ar gas purging and vacuum conditions. The effect of oxidation on the contact angle between liquid aluminum and Al2O3 was investigated. It was observed that aluminum samples in both Ar gas and vacuum condition were oxidized. With further increasing of the temperature, the oxide film gradually reacted with liquid Al and became thinner. The disruption of the thin oxide film caused the mutation of contact angle. The contact angle after mutation was approximately 130 degrees for both cases. The temperature of the turning point was lower under vacuum condition than under Ar gas purging. Under vacuum condition, the final stable contact angle was approximately 63 degrees above 1275 degrees C.

关键词： Contact angle Aluminum Al2O3 Oxidation

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Application of ultra-thin assembled planar metamaterial for wireless power transfer system

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Progress In electromagnetics Research C 2016年 65卷 153-162页

作者： Chen, Jun Feng Hu, Zhao Yang Wang, Shengming Liu, Minghai Cheng, Yongzhi Ding, Zhixia Wei, Bin Wang, Songcen State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan430074 China Engineering Research Center for Metallurgical Automation and Detecting Technology Ministry of Education Wuhan University of Science and Technology Wuhan430081 China School of Automation Huazhong University of Science and Technology Wuhan430074 China China Electric Power Research Institute Beijing100192 China

Magnetically coupled resonant wireless power transfer (WPT) has been employed in many applications, including wireless charging of portable electronic devices, electric vehicles, etc. However, the power transfer efficiency (PTE) decreases sharply due to divergence of magnetic field. electromagnetic (EM) metamaterial (MM) can control the direction of magnetic fields due to its negative effective permeability. In this paper, MMs with negative effective permeability at radio frequencies (RF) are applied to a WPT system operating at around 16.30 MHz for improvement of PTE. This ultra- thin and assembled planar MM structure consists of a single-sided periodic array of the capaci-tively loaded split ring resonators (CLSRRs). Both simulation and experiment are performed to cha-racterize the WPT system with and without MMs. The results indicate that the contribution of high PTE is due to the property of negative effective permeability. By integrating MM in the WPT system, the experimental results verify that the measured PTE with one and two MM slabs have respectively 10% and 17% improvement compared to the case without MM. The measured PTEs of the system at different transmission distances are also investigated. Finally, the proposed MM slabs are applied in a more practical WPT system (with a light bulb load) to reveal its effects. The results verify the efficiency improvement by the realized power being transferred to the load. © 2016, electromagnetics Academy. All rights reserved.

关键词： Metamaterials

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FPGA-Based Parallel Implementation of SURF Algorithm 22

FPGA-Based Parallel Implementation of SURF Algorithm

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22nd IEEE International Conference on Parallel and Distributed Systems (ICPADS)

作者： Chen, Wenjie Ding, Shuaishuai Chai, Zhilei He, Daojing Zhang, Weihua Zhang, Guanhua Peng, Qiwei Luo, Wang East China Normal Univ MoE Engn Res Ctr Software Hardware Codesign Techn Shanghai 200062 Peoples R China Jiangnan Univ Sch IoT Engn Wuxi 214122 Peoples R China State Key Lab Math Engn & Adv Comp Wuxi 214125 Peoples R China Fudan Univ Parallel Proc Inst Shanghai 200433 Peoples R China NARI Grp Corp State Grid Elect Power Res Inst Nanjing 211000 Jiangsu Peoples R China

ISBN: (纸本)9781509044573

SURF (Speeded up robust features) detection is used extensively in object detection, tracking and matching. However, due to its high complexity, it is usually a challenge to perform such detection in real time on a general-purpose processor. This paper proposes a parallel computing algorithm for the fast computation of SURF, which is specially designed for FPGAs. By efficiently exploiting the advantages of the architecture of an FPGA, and by appropriately handling the inherent parallelism of the SURF computation, the proposed algorithm is able to significantly reduce the computation time. Our experimental results show that, for an image with a resolution of 640x480, the processing time for computing using SURF is only 0.047 seconds on an FPGA (XC6SLX150T, 66.7 MHz), which is 13 times faster than when performed on a typical i3-3240 CPU (with a 3.4 GHz main frequency) and 249 times faster than when performed on a traditional ARM system (CortexTM-A8, 1 GHz).

关键词： SURF FPGA parallel computing High Level Synthesis

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Size Effect on Acoustic Emission Characteristics of Coal-Rock Damage Evolution

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ADVANCES IN MATERIALS SCIENCE AND engineering 2017年第1期2017卷 1-8页

作者： Wen, Zhijie Wang, Xiao Chen, Lianjun Lin, Guan Zhang, Hualei Anhui Univ Sci & Technol Key Lab Safety & High Efficiency Coal Min Minist Educ Huainan 232001 Peoples R China Shandong Univ Sci & Technol State Key Lab Min Disaster Prevent & Control Cofo Qingdao 266590 Peoples R China Shandong Univ Sci & Technol Minist Sci & Technol Qingdao 266590 Peoples R China Hong Kong Polytech Univ Dept Civil & Environm Engn Kowloon 999077 Hong Kong Peoples R China

Coal-gas outburst, rock burst, and other mine dynamic disasters are closely related to the instability and failure of coal-rock. Coal-rock is the assemblies of mineral particles of varying sizes and shapes bonded together by cementing materials. The damage and rupture process of coal-rock is accompanied by acoustic emission (AE), which can be used as an effective means to monitor and predict the instability of coal-rock body. In this manuscript, considering the size effect of coal-rock, the influence of different height to diameter ratio on the acoustic emission characteristics of coal-rock damage evolution was discussed by microparticle flow PFC2D software platform. The results show that coal-rock size influences the uniaxial compressive strength, peak strain, and elastic modulus of itself;the size effect has little effect on the acoustic emission law of coal-rock damage and the effects of the size of coal-rock samples on acoustic emission characteristics are mainly reflected in three aspects: the triggering time of acoustic emission, the strain range of strong acoustic emission, and the intensity of acoustic emission;the damage evolution of coal-rock specimen can be divided into 4 stages: initial damage, stable development, accelerated development, and damage.

关键词： ACOUSTIC emission MINES & mineral resources CEMENT composites GRANULAR flow FLOW (Fluid dynamics)

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A note on the weight of inverse complexity in improved hybrid genetic algorithm

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JOURNAL OF MEDICAL SYSTEMS 2016年第6期40卷 150-150页

作者： Lu, Siyuan Wang, Shuihua Zhang, Yudong Nanjing Normal Univ Nanjing 210023 Jiangsu Peoples R China

The article present the authors' comment on the study 'Intelligent medical disease diagnosis using improved hybrid genetic algorithm-multilayer perception network,' by F. Ahmad and colleagues, published in a 2013 issue of the 'Journal of Medical Systems.' Topics discussed include the utilization of machine learning and computer vision in the development of the diagnosis system, corrected form to equation two, and possible applications of the results.

关键词： Genetic Algorithm (GA) Complexity Inverse Note Taking

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