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Non-Inductive Start up of QUEST Plasma by RF Powert

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Plasma Science and Technology 2011年第3期13卷 307-311页

作者： K. hANADA h. ZUShI h. idei K. NAKAMURA M. IShIGURO S. TAShIMA E. I. KALINNIKOVA M. SAKAMOTO M. hASEGAWA A. FUJISAWA A. hIGAShIJIMA S. KAWASAKI h. NAKAShIMA h. LIU O. MITARAI T. MAEKAWA A. FUKUYAM Y. TAKASE J. QIAN Research Institute for Applied Mechanics Kyushu University Japan Interdisciplinary Graduate School of Engineering Science Kyushu University Japan School of Industrial Engineering Tokai University Japan Graduate School of Energy Science Kyoto University Japan Graduate School of Technology Kyoto University Japan Graduate School of Frontier Science University of Tokyo Japan Institute of Plasma Physics Chinese Academy of Sciences China

Both start-up and sustainment of plasma were successfully achieved by fully non- inductive current drive using microwave with a frequency of 8.2 Ghz. Plasmas current of 15 kA was implemented for 1 s. Magnetic surface reconstruction exhibited a plasma shape with an aspect ratio of below 1.5. The plasma current was dependent significantly on the launched microwave power and vertical magnetic field, while not affected by the mode of launched wave and the toroidal refractive index. hard X-ray （hXR） emitted from energetic electrons accelerated by the microwave was observed, and the discharge with a plasma current over 4 kA followed the same trend as the number of photons of 10 keV to 12 keV. This suggests that the plasma current may be driven by energetic electrons. Based on the experimental conditions, alternative explanations of how the plasma current could be driven are discussed.

关键词： steady-state operation of spherical tokamak non-inductive current drive QUEST

Initial testing of ohmic heating through double flux swing during electron cyclotron start-up in the QUEST spherical tokamak

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Plasma Science and Technology 2023年第5期25卷 31-36页

作者：张逸凡 Takumi ONChI Kazuo NAKAMURA 岳其霖 Takahiro NAGATA Shoji KAWASAKI Kengoh KURODA Makoto hASEGAWA Ryuya IKEZOE Takeshi IDO Kazuaki hANADA hiroshi idei Interdisciplinary Graduate School of Engineering Sciences Kyushu UniversityKasuga 816-8580Japan Research Institute for Applied Mechanics Kyushu UniversityKasuga 816-8580Japan

A power-supply system was developed for Ohmic heating(Oh)to double×10^(18)the amount of change magnetic flux in the primary central solenoid(CS)on the QUEST spherical *** power supplies are connected with stacks of insulated-gate bipolar transistors,and sequentially operated to generate positive and negative CS *** bipolar power-supply system is controlled via a field-programmable gate array,which guarantees the safety of the entire system *** new Oh system,assisted by electron cyclotron heating,enables the stable generation of plasma currents exceeding 100 k ***,the achieved electron density over the wide range in the major radial direction exceeds the cut-off density for one of the highpower microwave sources in *** strategy yields target plasmas for future experiments with the electron Bernstein wave.

关键词： spherical tokamak ohmic heating electron cyclotron heating FPGA

植物系统发生海报——以演化视角介绍植物多样性的科教资料项目

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生物多样性 2025年

作者：蒋陈焜郁文彬饶广远黎怀成 Julien B.Bachelier hartmut h.hilger Theodor C.h.Cole 北京大学生命科学学院蛋白质与植物基因研究国家重点实验室北京大学前沿交叉学科研究院北京大学-清华大学生命科学联合中心中国科学院西双版纳热带植物园综合保护中心/云南省热带雨林与亚洲象保护重点实验室 Dahlem Centre of Plant Sciences (DCPS)， Institute of Biology， Structural and Functional Plant Diversity， Freie Universit?t Berlin

中国的植物多样性保护行动虽然提升了公众对多样性的认识，但这些努力往往未能深入到理解植物多样性演化及其保护的深层意义。从演化的视角进行植物多样性宣传教育，有利于促进对多样性的综合理解，增进对多样性保护的认可。然而， ... 详细信息

中国的植物多样性保护行动虽然提升了公众对多样性的认识，但这些努力往往未能深入到理解植物多样性演化及其保护的深层意义。从演化的视角进行植物多样性宣传教育，有利于促进对多样性的综合理解，增进对多样性保护的认可。然而，现有资料多集中于物种的识别、鉴定与分类，缺乏从生物演化角度对植物多样性进行系统性介绍的内容。本文介绍了一个具有全球影响力的科教资料案例——由美裔德国植物学家Theodor C. h. Cole发起的植物系统发生海报(Plant Phylogeny Posters)项目。该项目通过整合最新的系统与演化植物学研究成果，以系统发生为线索介绍植物多样性及其亲缘关系，旨在利用系统发生树所蕴含的丰富演化思想内涵，启发读者理解植物多样性与演化。海报以系统发生树结合植物类群的形态、地理分布、物种数量等数据信息，直观展示了多个分类等级的重要类群的演化历史。在数十所大学和科研机构的45位研究人员的努力下， 70张系统发生海报已被翻译成中文，并向所有人免费开放获取。这一科教项目有望为增进公众深入理解植物多样性及其保护行动提供宝贵的资源和帮助。

关键词：植物多样性演化系统发生科教资料

h_∞Loop Shaping Control for Plasma Vertical Position Instability on QUEST

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Plasma Science and Technology 2013年第3期15卷 295-299页

作者：刘晓龙 Kazuo NAKAMURA Tatsuya YOShISUE Osamu MITARAI Makoto hASEGAWA Kazutoshi TOKUNAGA 薛二兵 hideki ZUShI Kazuaki hANADA Akihide FUJISAWA hiroshi idei Shoji KAWASAKI hisatoshi NAKAShIMA Aki hIGAShIJIMA Kuniaki ARAKI IGSES Kyushu University RIAM Kyushu University Tokai University

QUEST has a divertor configuration with a high and a negative n-index, and the problem of plasma vertical position instability control in QUEST is still under extensive study for achieving high efficiency plasma. The instability we considered is that the toroidal plasma moves either up or down in the vacuum chamber until it meets the vessel wall and is extinguished. The actively controlled coils （hCU and hCL） outside the vacuum vessel are serially connected in feedback with a measurement of the plasma vertical position to provide stabilizing control. In this work, a robust controller is employed by using the loop synthesis method, and provides robust stability over a wide range of n-index. Moreover, the gain of the robust controller is lower than that of a typical proportional derivative （PD） controller in the operational frequency range; it indicates that the robust controller needs less power consumption than the PD controller does.

关键词： vertical position instability robust control loop shaping QUEST

Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

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Neural Regeneration Research 2025年第6期20卷 1789-1800页

作者： Carina hromada Patrick heimel Markus Kerbl LászlóGál Sylvia Nürnberger Barbara Schaedl James Ferguson Nicole Swiadek Xavier Monforte Johannes C.heinzel Antal Nógrádi Andreas h.Teuschl-Woller David hercher Department Life Science Engineering University of Applied Sciences Technikum WienViennaAustria Austrian Cluster for Tissue Regeneration ViennaAustria Ludwig Boltzmann Institute for Traumatology The Research Center in Cooperation with AUVAViennaAustria University Clinic of Dentistry Medical University of ViennaViennaAustria Department of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical University of Vienna Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Department of hand- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). however, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimizatio

关键词： axon regeneration blood vessel functional recovery macroporous nerve lesion peripheral nerve repair sciatic nerve silk-based nerve guidance conduit vascularization

New breakthrough:Building non-markovian environments for single-qubit systems at any time interval

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Science China(Physics,Mechanics & Astronomy) 2025年

作者： h. Z. Shen Center for Quantum Sciences and School of Physics Northeast Normal University

The proposal of quantum simulation provides a highly effective approach for experimental research on open quantum systems. To date, numerous quantum simulation studies pertaining to open quantum systems have been put forward,including Fanchini et al.’s simulation of a dephasing noise channel utilizing an optical system[1], and Xiong et al.’s realization of a quantum simulation for a non-rotating-wave approximation noise channel, also leveraging an optical system[2].

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Computer Simulation of Effect of Intergrain Exchange Interaction on Magnetic Properties of Nanocomposite Magnets

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Journal of Rare Earths 2004年第1期22卷 146-151页

作者： Fukunaga h Mukaino h Department of Electrical Engineering & Electronics Graduate School of Science & Technology Nagasaki University Nagasaki 852-8521 Japan Nagasaki University Nagasaki 852-8521 Japan

Effects of the intergrain exchange interaction on magnetic properties of nanocomposite magnets were investigated by using the computer simulation based on the micromagnetic theory. The simulation was carried out under the assumptions that the strength of the intergrain exchange interaction is weaker than that of the intragrain exchange interaction, that inhomogeneous nanostructures result in the distribution of the strength of the intergrain exchange interaction, and that there exists nonmagnetic intergranular phase (NMIP) between grain boundaries. The distribution of the strength of the intergrain exchange interaction was simulated by the lognormal distribution with the standard deviation of σ.The calculations for Nd 2Fe 14B/α-Fe nanocomposite magnets reveal that a suitably weak intergrain exchange interaction and small grain size enable us to improve magnetic properties. It is also found that a Nd 2Fe 14B/α-Fe nanocomposite magnet has a potential of a (Bh) max value exceeding 300 kJ·m -3. On the other hand, the calculations for Nd 2Fe 14B/Fe 3B nanocomposite magnets reveal that the distribution of the strength of the intergrain exchange interaction deteriorates magnetic properties significantly. Particularly, this tendency is remarkable, when the grain size L is larger than its optimum value, 11 nm. The existence of nonmagnetic boundary layers accelerats this tendency. At σ=0.2, the calculated demagnetization curve for the model magnet composed of Nd 2Fe 14B(36%)/Fe 3B(54%)/NMIP(10%) (Valume fraction) grains (L=15 nm) agrees with that obtained experimentally for a Nd 2Fe 14B/Fe 3B nanocomposite magnet. These results suggest importance of refinement of grain size, suppression of a nonmagnetic intergranular phase, and preparation of homogeneous nanostructure for superior magnetic properties.

关键词： metal materials nanocomposite magnet exchange interaction nanostructure remanence intergranular phase

A simple tight-binding approach to topological superconductivity in monolayer MoS2

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Chinese Physics B 2020年第2期29卷 425-431页

作者： h Simchi Department of Physics Iran University of Science and TechnologyNarmakTehran 16844Iran Iran Semicondutor Technology Center Tehran 19575-199Iran

Monolayer molybdenum disulfide(MoS2)has a honeycomb crystal ***,with considering the triangular sublattice of molybdenum atoms,a simple tight-binding hamiltonian is introduced(derived)for studying the phase transition and topological superconductivity in MoS2 under uniaxial *** is shown that spin-singlet p+ip wave phase is a topological superconducting phase with nonzero Chern *** the chemical potential is greater(smaller)than the spin-orbit coupling(SOC)strength,the Chern number is equal to four(two)and otherwise it is equal to ***,the results show that,if the superconductivity energy gap is smaller than the SOC strength and the chemical potential is greater than the SOC strength,the zero energy Majorana states ***,we show that the topological superconducting phase is preserved under uniaxial strain.

关键词： MoS2 topological superconductivity Chern number band inversion

Peristaltic flow of Johnson-Segalman fluid in asymmetric channel with convective boundary conditions

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Applied Mathematics and Mechanics(English Edition) 2014年第6期35卷 697-716页

作者： h.YASMIN T.hAYAT A.ALSAEDI h.h.ALSULAMI Department of Mathematics Quaid-i-Azam University Nonlinear Analysis and Applied Mathematics (NAAM) Research Group Faculty of Science King Abdulaziz University

This work is concerned with the peristaltic transport of the Johnson-Segalman fluid in an asymmetric channel with convective boundary conditions. The mathematical modeling is based upon the conservation laws of mass, linear momentum, and energy. The resulting equations are solved after long wavelength and low Reynolds number are used. The results for the axial pressure gradient, velocity, and temperature profiles are obtained for small Weissenberg number. The expressions of the pressure gra-dient, velocity, and temperature are analyzed for various embedded parameters. Pumping and trapping phenomena are also explored.

关键词： asymmetric channel convective condition pumping and trapping Johnson-Segalman fluid