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Simultaneous estimation of spacecraft position and asteroid diameter during final approach of Hayabusa2 to Ryugu

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Astrodynamics 2020年第2期4卷 163-175页

作者： yuki Tak.o Yuya Mimasu Yuichi Tsuda Institute of Space and Astronautical Science Japan Aerospace Exploration AgencySagamihara252-5210Japan

This paper presents the optical navigation results of the asteroid explorer Hayabusa2 during the final rendezvous approach phase with the asteroid *** orbit determination of Hayabusa2 during the cruising phase uses a triangulation-based method that estimates the probe and asteroid orbits using the directions from which they are ***,the asteroid size is available as optical information just prior to *** size information allows us to estimate the relative distance between the probe and the asteroid with high accuracy,that is strongly related to the success or failure of the *** this study,the relative distance and asteroid size in real space are simultaneously estimated in real time by focusing on the rate of change of the asteroid size observed in sequential *** real-time estimation results coincided with those of precise analyses performed after arrival.

关键词： asteroids small bodies optical navigation size estimation orbit determination real time

Synergy of single-cell sequencing analyses and in vivo lineage-tracing approaches:A new opportunity for stem cell biology

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BIOCELL 2022年第5期46卷 1157-1162页

作者： yuki MATSUSHITA WANIDA ONO NORIAk. ONO School of Dentistry University of Texas Health Science Center at HoustonHouston77054USA

Single-cell sequencing technologies have rapidly progressed in recent years,and been applied to characterize stem cells in a number of ***(postnatal)stem cells are generally identified using combinations of cell surface mark.rs and transcription ***,it has been challenging to define micro-heterogeneity within“stem cell”populations,each of which stands at a different level of *** stem cells become defined at a single-cell level,their differentiation path becomes clearly ***,this viewpoint discusses the potential synergy of single-cell sequencing analyses with in vivo lineage-tracing approaches,with an emphasis on practical considerations in stem cell biology.

关键词： Single-cell sequencing in vivo lineage-lineage sk.letal stem cells(SSCs) mesenchymal stem cells(MSCs) bone marrow stromal cells(BMSCs)

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“渐修”爱情

大学生 2024年第9期 74-74页

作者： yuki 美国莎拉劳伦斯学院

“对你们而言,什么是爱情?”本学期最后一节课上,禅学教授一反常态地将文献搁置一旁,突然向我们发问。眼见大家面面相觑,“宗师”爽朗地大笑几声,提醒我们应该脱离抽象的思辩世界,转向自身感悟爱情的“真谛”。若是能从理论汪洋中寻找答... 详细信息

“对你们而言,什么是爱情?”本学期最后一节课上,禅学教授一反常态地将文献搁置一旁,突然向我们发问。眼见大家面面相觑,“宗师”爽朗地大笑几声,提醒我们应该脱离抽象的思辩世界,转向自身感悟爱情的“真谛”。若是能从理论汪洋中寻找答案,我一定会自信地给出David Velleman在《爱作为道德情感》中的结论:“爱的本质是给予彼此独特人格的珍重。”如何在生活中体会爱?我曾以为爱情是浑然天成的互补。

关键词：道德情感爱的本质浑然天成发问爱情

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Hemodynamic Profiling Using a Cardiac Index–Systemic Vascular Resistance Plot in Patients with Fontan Circulation

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Congenital Heart Disease 2023年第4期18卷 431-445页

作者： yuki k.wasak. Tak.shi Sasak. Daisuk. k.bayashi Division of Pediatric Cardiology Osaka City General Hospital Pediatric Medical CenterOsaka5340021Japan Division of Cardiology St.Louis Children’s HospitalDepartment of PediatricsWashington University in St.LouisSt.LouisMO 63130USA

Back.round: Elevated Fontan pressure (FP) alone cannot fully predict clinical outcomes. We hypothesized thathemodynamic profiling using a cardiac index (CI)-systemic vascular resistance (SVR) plot could characterize clinicalfeatures and predict the prognosis of post-Fontan patients. Methods: We included post-Fontan patients whounderwent cardiac catheterization at age k.Heart Association I/II and had a significantly lower pulmonary vascularresistance index (PVRI). Patients in category C had lower pulmonary/systemic blood flow. Patients in category Dhad a higher PVRI and had the poorest freedom from the endpoint (44% at 5 years). Elevated FP and category Dwere outcome predictors. Conclusions: CI-SVR plots was a novel adjunctive method for Fontan hemodynamicprofiling.

关键词： Cardiac index systemic vascular resistance perfusion pressure hemodynamic category fontan circulation prognosis

A preliminary study on the effects of line and selective thinning on bird communities in Hok.aido, northern Japan

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Journal of Forestry Research 2013年第3期24卷 553-559页

作者： Yuya Toyoshima Yuichi Yamaura yuki Yabuhara Futoshi Nak.mura Division of Environmental Resources Graduate School of Agriculture Hokkaido UniversityNishi 9 Kita 9 Kitaku Sapporo Hokkaido 0608589 Japan

In Japan, selective thinning is a common thinning method, though line thinning receives much attention because of its economic merits. In this study, we examined effects of the two thinning methods on bird communities in Todo fir （Abies sachalinensis） plantations in Hok. k.ido, Japan. We surveyed bird species in forests under four different management types - unthinned, selectively thinned, line-thinned planta- tion, and naturally regenerated forest （here after referred to as natural forest） stands - using a line-transect method. We also investigated vege- tation structure （canopy tree and understory） of these stands. Bird species richness did not differ between natural forests and plantations, while bird total abundance was greater in plantations than in natural forests. Bird species richness and total abundance were comparable among the three management types for plantations. Abundances of 10 bird species were different among the four management types, and five species were more abundant in line-thinned plantations. However, two species were more abundant in selectively thinned stands than in line-thinned stands, and they frequently appeared in natural forests. There were no distinct differ- ences in vegetation structure among the management types for planta- tions. Our results suggest that line thinning could be beneficial for some bird species in plantations.

关键词： line thinning selective thinning Todo fir (Abies sachalinen-sis) plantation improved indicator species analysis bird community

Polystyrene-based blend nanorods with gradient composition distribution

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Science China Chemistry 2012年第5期55卷 726-734页

作者： WU Hui SU ZhaoHui TERAYAMA yuki TAk.HARA Atsushi Institute for Materials Chemistry and Engineering Kyushu University Fukuoka 819-0395 Japan State k.y Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China Graduate School of Engineering Kyushu University Fukuoka 819-0395 Japan

The polystyrene-based polymer blends, partially miscible poly(bisphenol A carbonate)/polystyrene (PC/PS) and completely miscible poly(2,6-dimethylphenylene oxide)/polystyrene (PPO/PS), in nanorods with gradient composition distribution were discussed. The polymer blend nanorods were prepared by infiltrating the polymer blends into nanopores of anodic aluminum oxide (AAO) templates via capillary action. Their morphology was investigated by micro-Fourier transform infrared spectroscopy (micro-FTIR) and nano-thermal analysis (nano-TA) with spatial resolution. The composition gradient of polymer blends in the nanopores is governed by the difference of viscosity and miscibility between the two polymers in the blends and the pore diameter. The capillary wetting of porous AAO templates by polymer blends offers a unique method to fabricate functional nanostructured materials with gradient composition distribution for the potential application to nanodevices.

关键词： nanorods gradient composition distribution polymer blends anodic aluminum oxide micro-FTIR nano-TA

Water-assisted self-sustained burning of metallic single-walled carbon nanotubes for scalable transistor fabrication

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Nano Research 2017年第9期10卷 3248-3260页

作者： k.igo Otsuk. Taik. Inoue yuki Shimomura Shohei Chiashi Shigeo Maruyama Department of Mechanical Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan Energy NanoEngineering Lab. National Institute of Advanced Industrial Science and Technology (AIST) 1-2-1 Namiki Tsukuba 305-8564 Japan

Although aligned arrays of semiconducting single-walled carbon nanotubes (s-SWNTs) are promising for use in next-generation electronics owing to their ultrathin bodies and ideal electrical properties, even a small portion of metallic (m-) counterparts causes excessive leak.ge in field-effect transistors (FETs). To fully exploit the benefits of s-SWNTs for use in large-scale systems, it is necessary to completely eliminate m-SWNTs from as-grown SWNT arrays and thereby obtain purely semiconducting large-area arrays, wherein numerous FETs can be flexibly built. In this study, we performed electrical burning of m-SWNTs assisted by water vapor and polymer coating to eliminate m-SWNTs over a long length for the scalable fabrication of transistors from the remaining s-SWNT arrays. During the electrical-break.own process, the combination of water vapor and the polymer coating significantly enhanced the burning of the SWNTs, resulting in a self-sustained reaction along the nanotube axis. We found that m-SWNT segments partially remaining on the anode side resulted from one-way burning from the initial break.own position, where Joule-heating-induced oxidation first occurred. The s-SWNT-enriched arrays obtained were used to fabricate multiple FETs with a high on-off current ratio. The results indicate the advantages of this approach over conventional electrical break.own for the large-scale purification of s-SWNTs.

关键词： single-walled carbon nanotubes field-effect transistor selective removal electrical break.own one-way burning

Self-calibration and Compensation of Setting Errors for Surface Profile Measurement of a Microstructured Roll Work.iece

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Chinese Journal of Mechanical Engineering 2014年第1期27卷 14-22页

作者： GAO Wei XU Bin TAk.ISHI Toshik. SHIMIZU yuki ITO So Department of Nanomechanics Tohoku University School of Manufacturing Science and Engineering Sichuan University

Microstructured roll work.ieces have been widely used as functional components in the precision industries. Current researches on quality control have focused on surface profile measurement of microstructured roll work.ieces, and types of measurement systems and measurement methods have been developed. However, low measurement efficiency and low measurement accuracy caused by setting errors are the common disadvantages for surface profile measurement of microstructured roll work.ieces. In order to shorten the measurement time and enhance the measurement accuracy, a method for self-calibration and compensation of setting errors is proposed for surface profile measurement of microstructured roll work.ieces. A measurement system is constructed for the measurement, in which a precision spindle is employed to rotate the roll work.iece and an air-bearing displacement sensor with a micro-stylus probe is employed to scan the microstructured surface of the roll work.iece. The resolution of the displacement sensor is 0.14 nm and that of the rotary encoder of the spindle was 0.15r~. Geometrical and mathematical models are established for analyzing the influences of the setting errors of the roll work.iece and the displacement sensor with respect to the axis of the spindle, including the eccentric error of the roll work.iece, the offset error of the sensor axis and the zero point error of the sensor output. Measurement experiments are carded out on a roll work.iece on which periodic microstructures are a period of 133 i^m along the circumferential direction. Experimental results demonstrate the feasibility of the self-compensation method. The proposed method can be used to detect and compensate the setting errors without using any additional accurate artifact.

关键词： measurement profile setting error self-calibration compensation microstructure roll work.iece

Physical Properties of Liquid Terbium Measured by Levitation Techniques

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Journal of Rare Earths 2007年第6期25卷 665-669页

作者： Paul-Francois Paradis Tak.hik. Ishik.wa Noriyuki k.ik. yuki Watanabe Japan Aerospace Exploration Agency Institute of Space and Astronautical Science ISS Science Project Office 2-1-1 Sengen Tsukuba Ibaraki 305-8505 Japan Chiba Institute of Technology Tsudanuma Narashino Chiba Japan Advanced Engineering Service Co. Ltd. Tsukuba Ibaraki 305-0032 Japan

To understand the nature and behavior of rare earth metals in their liquid phases, accurate values of their physical properties are essential. However, to measure their physical properties, the samples should be maintained in liquid phases for prolonged time, and this raises a formidable challenge. This is mainly explained by their high melting temperatures （e.g., 1629 k.for Tb）, high vapor pressure, and the risk.of melt contamination with a crucible or support. An electrostatic levitation furnace alleviated these difficulties and allowed the determination of density, surface tension, and viscosity of several metals above their melting temperature. Here, first, the levitation furnace facility and the noncontact diagnostic procedures were briefly discussed, followed by the explanation of their thermophysical property measurements over wide temperature ranges. The density was obtained using an ultraviolet-based imaging technique that allowed excellent illumination, even at elevated temperatures. Over the 1615 to 1880 k.temperature span, the density measurements could be expressed as p（T） =7.84 × 10^3 -0.47 （T - Tm）（k. · m^-3） with Tm = 1629 k. yielding a volume expansion coefficient a（T） = 6.0 × 10^-5 （k.-1）. In addition, the surface tension and the viscosity could be determined by inducing a drop oscillation to a molten sample. Using this technique, the surface tension data could be expressed as σ（T） = 8.93 × 10^2 - 0.10 （T - Tm）（mN· m^-1） and those for viscosity as η（T） =0.583 exp [4.1 × 10^4/（RT）] （MPa·s） over the 1690 to 1980 k.temperature range

关键词： levitation liquid noncontact terbium rare earths