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Modeling and analysis of Hayabusa2 touchdown

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Astrodynamics 2020年第2期4卷 119-135页

作者： Kent Yoshikawa Hirotaka Sawada Shota kikuchi Naoko Ogawa Yuya Mimasu Go ono Yuto Takei Fuyuto Terui Takanao Saiki Seiji Yasuda Kota Matsushima Tetsuya Masuda Yuichi Tsuda Japan Aerospace Exploration Agency Sagamihara252-5210Japan NEC Corporation Fuchu183-8501Japan

The Hayabusa2 asteroid explorer mission focuses principally on the touchdown and sampling on near-Earth asteroid 162173 ***2 successfully landed on its surface and ejected a projectile for sample collection on February 22,***2 later landed near a crater formed by an impactor and executed the sampling sequence again on July 11,*** a successful mission,a thorough understanding and evaluation of spacecraft dynamics during touchdown were *** most challenging aspect of this study was the modeling of such spacecraft phenomena as the dynamics of landing on a surface with unknown *** particular,a Monte Carlo analysis was used to determine the parameters of the operational design for the final descent and touchdown *** paper discusses the dynamical modeling of the simulation during the touchdown of Hayabusa2.

关键词： contact dynamics resistive force theory(RFT) astrodynamics Hayabusa2 planetary exploration

Mechanically strengthened graphene-Cu composite with reduced thermal expansion towards interconnect applications

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Microsystems & Nanoengineering 2019年第1期5卷 481-491页

作者： Zhonglie An Jinhua Li Akio kikuchi Zhuqing Wang Yonggang Jiang Takahito ono Graduate School of Engineering Tohoku UniversityAramaki-Aza-Aoba 6-6-01Aoba-kuSendai 980-8579Japan Research Institute for Engineering and Technology Tohoku Gakuin UniversityTagajo 985-8537Japan School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191PR China Department of Mechanical Systems Engineering Tokyo University of Agriculture and TechnologyKoganei 184-8588Japan

High-density integration technologies with copper(Cu)through-silicon via(TSV)have emerged as viable alternatives for achieving the requisite integration densities for the portable electronics and micro-electro-mechanical systems(MEMSs)***,significant thermo-mechanical stresses can be introduced in integrated structures during the manufacturing process due to mismatches of thermal expansion and the mechanical properties between Cu and silicon(Si).The high-density integration demands an interconnection material with a strong mechanical strength and small thermal expansion *** this study,a novel electroplating method is developed for the synthesis of a graphene-copper(G-Cu)composite with electrochemically exfoliated *** fabrication and evaluation of the G-Cu composite microstructures,including the microcantilevers and micromirrors supported by the composite,are *** evaluated not only the micromechanical properties of the G-Cu composite based on in-situ mechanical resonant frequency measurements using a laser Doppler vibrometer but also the coefficients of thermal expansion(CTE)of the composite based on curvature radius measurements at a temperature range of 20–200℃.The Young’s modulus and shear modulus of the composite are approximately 123 and 51 GPa,which are 1.25 times greater and 1.22 times greater,respectively,than those of pure Cu due to the reinforcement of *** G-Cu composite exhibits a 23%lower CTE than Cu without sacrificing electrical *** results show that the mechanically strengthened G-Cu composite with reduced thermal expansion is an ideal and reliable interconnection material instead of Cu for complex integration structures.

关键词： composite expansion thermal

Towards a sustainable technology for production of extra-pure Ti metal:Electrolysis of sulfurized Ti(C,N)in molten CaCl_(2)

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International Journal of Minerals,Metallurgy and Materials 2020年第12期27卷 1635-1643页

作者： Eltefat Ahmadi Ryosuke O.Suzuki Tatsuya kikuchi Takumi Kaneko Yuta Yashima Division of Materials Science and Engineering Faculty of EngineeringHokkaido UniversitySapporo 060-8628Japan Japan Society for the Promotion of Science(JSPS) Tokyo 102-0083Japan

A new concept for producing highly pure Ti metal powder from ilmenite(FeTiO)_(3))is proposed in this *** nitride(TiN)or titanium oxycarbonitride(TiO_(x)C_(y)N_(z))could be synthesized in the first step via the simultaneous carbothermal reduction and nitridation(CTRN)of FeTiO3 to remove oxygen *** separate oxygen completely,high-quality TiS2 samples were then synthesized from TiN and TiC using S2 gas,and the clean sulfides were finally reduced toα-Ti powders with spherical morphology using electrolysis in molten CaCl_(2).Xray diffraction(XRD),scanning electron microscopy(SEM)in conjunction with energy-dispersive X-ray spectroscopy(EDS),and elemental LECO analysis were used to study the phases and microstructures of the sulfides and the electrochemically reduced *** Ti powder showed no carbon contamination and consisted of high-purity foil-like Ti sheets with very low oxygen,carbon,and nitrogen contents of less than 0.15 wt%O,0.02 wt%C,and 0.003 wt%N,*** quality of the Ti powder was much higher than that of the powder obtained using the conventional OS process(proposed by *** and ***)starting directly from the oxides.

关键词： titanium molten salt electrolysis sulfidation titanium oxycarbonitride ilmenite

Motion reconstruction of the small carry-on impactor aboard Hayabusa2

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Astrodynamics 2020年第4期4卷 289-308页

作者： Takanao Saiki Yuya Mimasu Yuto Takei Manabu Yamada Hirotaka Sawada K azunori Ogawa Naoko Ogawa Hiroshi Takeuchi Akira Miura Yuri Shimaki Koji Wada Rie Honda Yasuhiro Yokota kei Shirai Naruhisa Sano Hirohito Ohtsuka Go ono Kent Yoshikawa Shota kikuchi Chikako Hirose Yukio Yamamoto Takahiro Iwata Masahiko Arakawa Seiji Sugita Satoshi Tanaka Fuyuto Terui Makoto Yoshikawa Satoru Nakazawa Sei-ichiro Watanabe Yuichi Tsuda Japan Aerospace Exploration Agency Sagamihara 252-5210Japan Chiba Institute of Technology Narashino 275-0016Japan Kobe University K obe 657-8501Japan The Graduate University for Aduanced Studies Sagamihara 252-5210Japan Kochi University Kochi 780-8520Japan IHI Aerospace Co. LtdTomioka 370-2398Japan The University of Tokyo Tokyo 113-0033Japan Nagoya University Nagoya 464-8601Japan

Subsurface exploration is one of the most ambitious scientific objectives of the Hayabusa2 mission.A small device called small carry-on impactor(SCI)was developed to create an artificial crater on the surface of asteroid *** enables us to sample subsurface materials,which will provide a window to the *** physical properties of the resulting crater are also useful for understanding the internal structure of *** understanding of the crater and ejecta properties,including the depth of excavation of subsurface materials,requires accurate information on impact *** particular,the impact angle is a critical factor because it greatly influences the size and shape of the *** April 5,2019,the Hayabusa2 spacecraft deployed the SCI at 500 m of altitude above the asteroid *** SCI gradually reduced its altitude,and it shot a 2 kg copper projectile into the asteroid 40 min after *** the position of the released SCI is essential for determining the impact *** study describes the motion reconstruction of the SCI based on the actual operation *** results indicate that the SCI was released with high accuracy.

关键词： small body exploration Hayabusa2 kinetic impact artificial crater motion reconstruction

The deep-space multi-object orbit determination system and its application to Hayabusa2’s asteroid proximity operations

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Astrodynamics 2020年第4期4卷 377-392页

作者： Hiroshi Takeuchi Kent Yoshikawa Yuto Takei Yusuke Oki Shota kikuchi Hitoshi Ikeda Stefania Soldini Naoko Ogawa Yuya Mimasu Go ono Fuyuto Terui Naoya Sakatani Manabu Yamada Toru Kouyama Shingo Kameda Takanao Saiki Yuichi Tsuda Institute of Space and A stronautical Science Japan A erospace Exploration AgencySagamihara 252-5210Japan The Graduate University for Aduanced Studies Hayama 240-0193Japan Research and Development Directorate Japan Aerospace Exploration AgencySagamihara 252-5210Japan University of Liverpool Liverpool L693BXUK Chiba Institute of Technology Narashino 275-0016Japan National Institute of Aduanced Industrial Science and Technology Koto-ku 135-0064Japan Rikkyo University Toshima-ku 171-8501Japan

The deep-space multi-object orbit determination system(DMOODS)and its application in the asteroid proximity operation of the Hayabusa2 mission are *** was developed by the Japan Aerospace Exploration Agency(JAXA)for the primary purpose of determining the trajectory of deep-space spacecraft for JAXA’s planetary *** weighted least-squares batch filter is used for the orbit estimator of *** orbit estimator supports more than 10 data types,some of which are used for relative trajectory measurements between multiple space objects including natural satellites and small *** system consists of a set of computer programs running on Linux-based consumer PCs on the ground,which are used for orbit determination and the generation of radiometric tracking data,such as delta differential one-way ranging and doppler tracking *** the asteroid proximity phase of Hayabusa2,this system played an essential role in operations that had very strict navigation requirements or operations in which few optical data were obtained owing to special constraints on the spacecraft attitude or distance from the *** example is orbit determination during the solar conjunction phase,in which the navigation accuracy is degraded by the effect of the solar *** large range bias caused by the solar corona was accurately estimated with DMOODS by combining light detection and ranging(LIDAR)and ranging measurements in the superior solar conjunction phase of *** the orbiting operations of target markers and the MINERVA-II2 rover,the simultaneous estimation of six trajectories of four artificial objects and a natural object was made by *** type of simultaneous orbit determination of multi-artificial objects in deep-space has never been accomplished before.

关键词： orbit determination optical navigation gravity measurements superior solar conjunction delta differential one-way ranging(delta-DOR)

Hayabusa2’s superior solar conjunction mission operations: Planning and post-operation results

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Astrodynamics 2020年第4期4卷 265-288页

作者： Stefania Soldini Hiroshi Takeuchi Sho Taniguchi Shota kikuchi Yuto Takei Go ono Masaya Nakano Takafumi Ohnishi Takanao Saiki Yuichi Tsuda Fuyuto Terui Naoko OgawaYuya MimasuTadateru Takahashi Atsushi Fujii Satoru NakazawaKent Yoshikawa Yusuke Oki Chikako Hirose Hirotaka Sawada Tomohiro Yamaguchi Makoto Yoshikawa Department of Mechanical Materials and Aerospace EngineeringUniversity of LiverpoolLiverpool L693BXUK Institute of Space and Astronautical Science Japan Aerospace Exploration AgencySagamihara 252-5210Japan Fujitsu Limited Tokyo 105-7123Japan Mitsubishi Electric Corporation Tokyo 100-8310Japan

In late 2018,the asteroid Ryugu was in the Sun's shadow during the superior solar conjunction *** the Sun-Earth-Ryugu angle decreased to below 3°,the Hayabusa2 spacecraft experienced 21 days of planned blackout in the Earth-probe communication *** was the first time a spacecraft had experienced solar conjunction while hovering around a minor *** the safety of the spacecraft,a low energy transfer trajectory named Ayu was designed in the Hill reference frame to increase its altitude from 20 to 110 *** trajectory was planned with the newly developed optNEAR tool and validated with real time *** article shows the results of the conjunction operation,from planning to fight data.

关键词： superior solar conjunction Hayabusa2 Ryugu hovering satellite mission operations

Orbit insertion strategy of Hayabusa2’s rover with large release uncertainty around the asteroid Ryugu

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Astrodynamics 2020年第4期4卷 309-329页

作者： Yusuke Oki Kent Yoshikawa Hiroshi Takeuchi Shota kikuchi Hitosi Ikeda Daniel JScheeres Jay WMcMahon Junichiro Kawaguchi Yuto Takei Yuya Mimasu Naoko Ogawa Go ono Fuyuto Terui Manabu Yamada Toru Kouyama Shingo K ameda Kazuya Yoshida Kenji Nagaoka Tetsuo Yoshimitsu Takanao Saiki Yuichi Tsuda Japan A erospace Exploration Agency T'sukuba 305-8505Japan Japan Aerospace Exploration Agency Sagamihara 252-5210Japan University of Colorado BoulderCO 80309USA Planetary Exploration Research Center Chiba Institute of TechnologyNarashino 275-0016Japan National Institute of Aduanced Industrial Science and Technology Koto-ku 135-0064Japan Rikkyo University Toshima-ku 171-8501Japan Department of A erospace Engineering Tohoku UniversitySendai 980-8579Japan Kyushu Institute of Technology Kitakyusyu 804-8550Japan

This paper describes the orbit design of the deployable payload Rover 2 of MINERVA-II,installed on the Hayabusa2 *** Rover 2 did not have surface exploration capabilities,the operation team decided to experiment with a new strategy for its deployment to the *** rover was ejected at a high altitude and made a semi-hard landing on the surface of the asteroid Ryugu after several *** on the orbital analysis around Ryugu,the expected collision speed was tolerable for the rover to function *** the rover could not control its position,its motion was entirely governed by the initial ***,the largest challenge was to insert the rover into a stable orbit(despite its large release uncertainty),and avoid its escape from Ryugu due to an environment strongly perturbed by solar radiation pressure and gravitational *** study investigates the solution space of the orbit around Ryugu and evaluates the orbit’s robustness by utilizing Monte Carlo simulations to determine the orbit insertion *** analyzing the flight data of the rover operation,we verified that the rover orbited Ryugu for more than one period and established the possibility of a novel method for estimating the gravity of an asteroid.

关键词： solar radiation pressure augmented elliptic Hill three-body problem gravitational irregularity

Hepatocellular Carcinoma: The Final Moments of Life

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Journal of Cancer Therapy 2013年第2期4卷 377-383页

作者： Rodrigo Martins Abreu Camila Silva Ferreira Paulo Dominguez Nasser Luciana Oba Onishi kikuchi Flair José Carrilho Suzane Kioko ono Department of Gastroenterology Clinical Division Hepatology Branch University of Sao Paulo School of Medicine Sao Paulo Brazil

Hepatocellular carcinoma (HCC) is a wide world prevalent hepatic disease, being the third greater cancer related death cause and most of the patients are not eligible for liver transplant. Palliative care is an option for, in average, half of hepatocellular carcinoma diagnosed patients and only recently the molecular targeted drug, Sorafenib, has been introduced among the therapeutic options for these patients. The physical pain comes frequently associated with progression disease (metastasis). Patients may be very fragile, with immobility, loss of interest in food and beverage intake, as well as weakness and drowsiness. Therefore, it is important that health professionals start planning care with patients and their relatives, before the end-stage disease. Informing the patient about therapeutic options guarantee a doctor patient relationship improvement and more belief on the health team.

关键词： Hepatocellular Carcinoma Liver Cancer Palliative Care Terminally Ill Death

日本全国范围内各种显像剂实际使用剂量的调查报告

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中华核医学与分子影像杂志 2017年第7期37卷 445-445页

作者：唐军 Hiroshi Watanabe Kazunari Ishii Makoto Hosono Etsuko Imabayashi Koichiro Abe Masayuki Inubushi Kazuko Ohno Yasuhiro Magata kinya ono.kei kikuchi kei Wagatsuma Tadashi Takase Kyoko Saito Yasuyuki Takahashi 苏州大学附属第二医院核医学科 Department of Radiological Technology Japan Labour Health and Welfare Organization Yokohama Rosai Hospital Department of Radiology Kindai University Faculty of Medicine

目的医疗照射的最优化在世界范围内都是辐射防护所关心的重要问题之一,国际辐射防护委员会和国际原子能机构推荐建立显像剂使用的剂量参考水平（DRLs）作为控制医疗照射最优化的工具。因此,根据最新调查资料构建DRLs已成为各核医学相关... 详细信息

目的医疗照射的最优化在世界范围内都是辐射防护所关心的重要问题之一,国际辐射防护委员会和国际原子能机构推荐建立显像剂使用的剂量参考水平（DRLs）作为控制医疗照射最优化的工具。因此,根据最新调查资料构建DRLs已成为各核医学相关学会和组织的迫切需要。为构建此DRLs,本研究在全日本范围内调查了核医学成人用显像剂的实际使用剂量。方法调查在2014年11月25日至2015年1月16日间进行,使用调查表方式调查了全日本1249个医疗单位各种显像剂的使用情况,调查结果通过网络反馈收集。结果 516个医疗单位反馈了调查结果,反馈率41%。具体显像包括:99Tcm-MDP和99Tcm-HMDP的骨显像,99Tcm-HM-PAO、99Tcm-ECD和123I-IMP的脑血流显像,99Tcm-Tetrofosmin、99Tcm-MIBI和201Tl-Cl的心肌灌注显像,18F-FDG(自产18F或配送的18F)的肿瘤PET显像。以上显像的第75百分剂量分别是为932、937、763、775、200、831、818、180、235和252 MBq。日本90%以上的医疗单位所使用的显像剂剂量在上述剂量值中位数的50%范围内。很多医疗机构采用包装说明书、文本或指南推荐的剂量,比如740 MBq(99Tcm-MDP和99Tcm-HMDP骨显像)、740 MBq(99Tcm-ECD和99Tcm-HM-PAO脑血流显像)和740 MBq(99Tcm-Tetrofosmin和99Tcm-MIBI心肌灌注显像)等。99Tcm-MDP和99Tcm-HMDP（用于骨显像）、99Tcm-HM-PAO（用于脑血流显像）、99TcmTetrofosmin和99Tcm-MIBI（用于心肌灌注显像）等许多显像剂的使用剂量均在欧盟DRLs内,且大多数在日本使用的显像剂剂量均未超过美国核医学与分子影像学会的标准使用剂量上限。结论本调查结果表明,在日本所使用的各种核医学显像剂的剂量比较集中,各医疗机构均能按照文本和指南要求的剂量越来越严格地使用显像剂。此外,日本显像剂的使用剂量均在欧盟和美国核医学与分子影像学会所规定的使用剂量范围内。

关键词：调查诊断参考水平放射性药物放射性活度剂量最优化