Article
Instruments & Instrumentation
Hongtao Shen, Guofeng Zhang, Junsen Tang, Shulin Shi, Li Wang, Dingxiong Chen, Linjie Qi, He Ouyang, Xinyi Han, Kaiyong Wu, Xiaojun Sun, Yun He, Yiwen Bao, Ming He, Kimikazu Sasa, Shan Jiang
Summary: GXNU-AMS is a compact 14C accelerator mass spectrometer, which is one of the lowest designed energy AMS systems in China. It has a measurement accuracy of -0.6% and a measurement sensitivity of 14C/12C -3 x 10-15, which can meet the measurement requirements in the fields of life sciences and archaeology.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2022)
Article
Instruments & Instrumentation
Yusuke Yokoyama, Yosuke Miyairi, Takahiro Aze, Chikako Sawada, Yuka Ando, Satomi Izawa, Yoshiko Ueno, Shoko Hirabayashi, Naoto Fukuyo, Kosuke Ota, Yusuke Shimizu, Yuning Zeng, Hui Lan, Ren Tsuneoka, Kozue Ando, Karin Nemoto, Stephen Obrochta, Bethany Behrens, Evan Tam, Kai Leggett, Jian Rzeszewicz, Zihan Huang, Reisuke Kondo, Toshi Nagata
Summary: A single stage Accelerator Mass Spectrometer (YS-AMS) at the Atmosphere and Ocean Research Institute (AORI), University of Tokyo has been operating smoothly since 2013, with an average annual operation time of over 8000 hours. A newly developed automated system has dramatically increased the throughput, allowing for the measurement of 16,000 samples to date. The improved operation software and increased number of standards measured per run have resulted in a 14C/12C measurement precision on standard material of better than 0.1%. The results have enhanced geochronological information for paleoenvironmental, biological, and geohazard studies.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2022)
Article
Automation & Control Systems
Sze Sing Lee, Ricxon Jie Sheng Lim, Reza Barzegarkhoo, Chee Shen Lim, Felipe Bovolini Grigoletto, Yam Prasad Siwakoti
Summary: H-bridge inverters are commonly used in single-phase applications but their voltage gain is limited, so a two-stage power conversion is usually required. However, single-stage boost inverters are gaining popularity due to their higher efficiency and compactness. This article introduces a family of boost inverters with continuous DC source current, which can achieve voltage boosting and three-level generation within a single-stage operation. The article also presents various topologies using the same number of components and proposes an extension to generate five voltage levels with enhanced voltage gain. Thorough analysis, simulation, and experimental results are provided for verification.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Zhaowen Chen, Hao Zhang, Xiaoqiang Guo, Frede Blaabjerg
Summary: A new inverter topology and control method with better cost and loss characteristics are proposed in this paper. The topological characteristics and working mode of the inverter are analyzed, and a modulation scheme is designed to ensure the balance of the output capacitor voltage.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Kuo-Yuan Lo, Wei-Yu Wang
Summary: This article proposes a bidirectional isolated single-stage single-phase ac-ac converter with quasi-resonant topology, which features high conversion efficiency, simple control circuit, and bidirectional power flow capability. Hardware experimental results validate the performance of the converter.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2021)
Article
Materials Science, Multidisciplinary
Hanqiu Nie, Cong Zhao, Zujin Shi, Chuancheng Jia, Xuefeng Guo
Summary: Single-molecule techniques reveal new effects at the single-molecule scale and enable the development of functional devices for specific optoelectronic functions. Fullerene molecules, as a unique class of materials, offer opportunities for fabricating diverse single-molecule devices. The combination of fullerenes and single-molecule electronic techniques leads to the discovery of new principles and properties, as well as the functionalization of single-molecule devices.
ACS MATERIALS LETTERS
(2022)
Article
Automation & Control Systems
Fazal Akbar, Honnyong Cha, Heung-Geun Kim
Summary: A novel single-phase single-stage transformerless inverter is proposed in this article for grid-tied and standalone applications, featuring low leakage current and the ability to perform both buck and boost functions. This inverter can achieve high power density and conversion efficiency, as only one switch operates at a high frequency. Additionally, there is no need for inserting high-frequency dead-time between the switches, leading to improved performance.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Instruments & Instrumentation
E. F. Bueno, F. Barao, M. Vecchi
Summary: By utilizing precise measurements from the Alpha Magnetic Spectrometer (AMS-02), we have developed a parametric template fit method to accurately identify the isotopic composition of cosmic rays. Considering factors such as particle fragmentation and discrepancies between data and simulation, we are able to assess the performance of AMS-02 and demonstrate its capability to separate hydrogen isotopes.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2022)
Article
Automation & Control Systems
Xuefeng Hu, Bo Wen, Huiru Wang, Jiawei Chen
Summary: This study proposes a single-stage single-phase inverter for low-voltage input applications. By integrating a dual output dc-dc boost converter and two additional power switches, the proposed inverter achieves zero leakage current and can boost voltage capacity with fewer switching devices, reducing system cost.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Computer Science, Artificial Intelligence
Huixin Miao, Junqi Lin, Junjie Cao, Xiaoguang He, Zhixun Su, Risheng Liu
Summary: Existing multi-person pose estimators can be categorized into two-stage approaches (top-down and bottom-up approaches) and one-stage approaches. Two-stage methods either have additional person detectors with high computational redundancy or group keypoints heuristically after predicting all the instance-free keypoints. Single-stage methods, recently proposed, eliminate the need for the extra stages but have lower performance compared to the latest bottom-up approaches. This work presents a novel single-stage multi-person pose regression method called SMPR, which predicts instance-aware keypoints using dense prediction paradigm and incorporates better strategies for defining positive pose hypotheses and score estimation for improved pose estimation performance.
PATTERN RECOGNITION
(2023)
Article
Engineering, Electrical & Electronic
Jingmei Ning, Feipeng Da, Shaoyan Gai
Summary: In this study, a new method called DA-3DSSD is proposed for 3D object detection, which addresses the issue of nonuniformity in point clouds to improve detection precision. This method introduces strategies such as DPS and CDA to enhance the network's classification ability and achieve better results compared to baseline methods on the KITTI benchmark.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Aakash Kumar Seth, Mukhtiar Singh
Summary: This study introduces a single-phase, single-stage onboard plug-in electric vehicle charger, addressing the issue of second-order ripple component in single-phase PEV chargers during V2G mode and proposing a compensation technique. The use of a repetitive controller effectively reduces the ripple component.
IEEE TRANSACTIONS ON TRANSPORTATION ELECTRIFICATION
(2021)
Article
Computer Science, Artificial Intelligence
Tianyu Wang, Xiaowei Hu, Pheng-Ann Heng, Chi-Wing Fu
Summary: This article introduces a new problem, instance shadow detection, which aims to detect shadow instance and the associated object instance that cast each shadow in the input image. The article proposes a new dataset with masks for shadow instances, object instances, and shadow-object associations. A single-stage detector is designed to perform instance shadow detection, incorporating bidirectional relation learning and deformable maskIoU head to improve mask accuracy. The proposed method is quantitatively and qualitatively evaluated on a benchmark dataset, demonstrating its applicability in light direction estimation and photo editing.
IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE
(2023)
Article
Geochemistry & Geophysics
Martin Seiler, Pieter M. Grootes, Helene Svarva, Marie-Josee Nadeau
Summary: Atmospheric CO2 samples collected since the 1960s have been stored as CaCO3 in glass containers. The study investigated whether the stored samples can still be used for new measurements of atmospheric radiocarbon content and whether they have been contaminated. Various methods were attempted to clean the carbonate and release CO2 for remeasurements. The results showed significant changes in C-14 content for samples before 1970, indicating contamination during storage, and later samples from the 1970s showed lower contamination but still had added uncertainty, making them unreliable.
Article
Geochemistry & Geophysics
Corina Solis, Efrain Chavez, Arcadio Huerta, Maria Esther Ortiz, Alberto Alcantara, Maria Rodriguez-Ceja, Miguel Angel Martinez Carrillo
Summary: Augusto Moreno established the first radiocarbon laboratory in Mexico in the 1950s, but it wasn't until 2003 that C-14 measurement with AMS technology was achieved. By 2013, with advancements in AMS technology and sample preparation equipment, and support from UNAM and CONACYT, the Mexican AMS Laboratory LEMA became a reality.
Article
Geography, Physical
Adam D. Sproson, Yoshinori Takano, Yosuke Miyairi, Takahiro Aze, Hiroyuki Matsuzaki, Naohiko Ohkouchi, Yusuke Yokoyama
Summary: Studying the evolution of the East Antarctic Ice Sheet during the Holocene is crucial for understanding the mechanisms behind ice sheet retreat and predicting future sea-level rise. Beryllium isotope analysis of lake sediments has revealed local glacier melting and subglacial erosion, as well as contributed to the understanding of Antarctic ice sheet instabilities and their impact on global sea-level rise.
QUATERNARY SCIENCE REVIEWS
(2021)
Article
Biochemical Research Methods
Adam D. Sproson, Takahiro Aze, Bethany Behrens, Yusuke Yokoyama
Summary: Accurate determination of Be-10/Be-9 ratio is crucial in Earth Sciences research. HR-ICP-MS improves precision of Be-9 analysis for various geological materials, regardless of sample size or leaching strength, reducing uncertainties in Be-10/Be-9 ratios.
RAPID COMMUNICATIONS IN MASS SPECTROMETRY
(2021)
Article
Geography, Physical
Atsushi Uemine, Takaaki Watanabe, Fagang Wang, Masako Yamane
Summary: This study analyzed three lithic assemblages from the Shuilian Cave Site in Hebei Province, and found that the majority of artifacts correspond to the traditional small flake-tool industry in northern China. By examining lithic assemblages and human behavior, the adaptability of quartz small flake-tool industry was discussed.
QUATERNARY INTERNATIONAL
(2022)
Article
Multidisciplinary Sciences
Adam D. Sproson, Yusuke Yokoyama, Yosuke Miyairi, Takahiro Aze, Rebecca L. Totten
Summary: The ice loss in the Amundsen Sea sector of West Antarctica is accelerating rapidly. This study reveals that this region also experienced thinning and retreat from 9 to 6 thousand years ago, which was caused by atmospheric connections with a warming tropical Pacific. Understanding the processes responsible for ice mass loss is crucial for predicting sea-level rise.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
Ryo Nakanishi, Juichiro Ashi, Yosuke Miyairi, Yusuke Yokoyama
Summary: By investigating tsunami deposits in a coastal wetland of southeastern Hokkaido, Japan, this study reveals the history and extents of tsunamis generated by the Kuril Trench over the last 4,000 years, providing a framework for magnitude estimations and long-term forecasts of earthquakes.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Instruments & Instrumentation
Shigeyoshi Otosaka, Hyunduck Jeon, Yunxuan Hou, Takahiro Watanabe, Takahiro Aze, Yosuke Miyairi, Yusuke Yokoyama, Hiroshi Ogawa
Summary: A safer and easier method for analyzing DOC-14C in seawater was developed in this study, which introduced the use of a low-pressure mercury lamp for direct decomposition of organic matter. This method can not only be used for C-14 isotope ratio analysis, but also for analyzing various other dissolved organic elements/ isotopes.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2022)
Letter
Multidisciplinary Sciences
Yusuke Yokoyama, Kurt Lambeck, Patrick De Deckker, Tezer M. Esat, Jody M. Webster, Masao Nakada
NATURE COMMUNICATIONS
(2022)
Article
Geosciences, Multidisciplinary
Maximilian Hallenberger, Lars Reuning, Hideko Takayanagi, Yasufumi Iryu, Nina Keul, Takeshige Ishiwa, Yusuke Yokoyama
Summary: There is growing interest in using pteropods as archives of past changes in ocean chemistry. This study obtained core data from the Northwest Shelf of Australia to assess changes in carbonate saturation state using pteropod species Heliconoides inflatus. The findings indicate that H. inflatus calcifies at a depth of 95-140 m, confirming its accuracy in recording shallow-marine signals. The study also found a notable decrease in carbonate ion concentrations after 8.5 ka, associated with post-glacial humid conditions on the Northwest Shelf.
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2022)
Article
Instruments & Instrumentation
Yuning Zeng, Yusuke Yokoyama, Shoko Hirabayashi, Yosuke Miyairi, Atsushi Suzuki, Takahiro Aze, Yuta Kawakubo
Summary: A new method combining coral growth band counting and Sr/Ca measurement using ICP-AES was proposed to establish a high-resolution age model. The study demonstrated the feasibility of using Sr/Ca for age modeling in coral and the ability of ICP-AES to provide higher-resolution data.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2022)
Article
Instruments & Instrumentation
Yusuke Yokoyama, Yosuke Miyairi, Takahiro Aze, Chikako Sawada, Yuka Ando, Satomi Izawa, Yoshiko Ueno, Shoko Hirabayashi, Naoto Fukuyo, Kosuke Ota, Yusuke Shimizu, Yuning Zeng, Hui Lan, Ren Tsuneoka, Kozue Ando, Karin Nemoto, Stephen Obrochta, Bethany Behrens, Evan Tam, Kai Leggett, Jian Rzeszewicz, Zihan Huang, Reisuke Kondo, Toshi Nagata
Summary: A single stage Accelerator Mass Spectrometer (YS-AMS) at the Atmosphere and Ocean Research Institute (AORI), University of Tokyo has been operating smoothly since 2013, with an average annual operation time of over 8000 hours. A newly developed automated system has dramatically increased the throughput, allowing for the measurement of 16,000 samples to date. The improved operation software and increased number of standards measured per run have resulted in a 14C/12C measurement precision on standard material of better than 0.1%. The results have enhanced geochronological information for paleoenvironmental, biological, and geohazard studies.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2022)
Article
Multidisciplinary Sciences
Kaoru Kubota, Rosaaideihn Tanabe, Minoru Ikehara, Yukiko Kozaka, Koji Seike, Yosuke Miyairi, Yusuke Yokoyama
Summary: This article describes the use of geochemical data to determine the age model of marine sediment cores collected from Agulhas Ridge in the South Atlantic Ocean. The dataset includes radiocarbon ages of planktonic foraminifera shells and oxygen isotopes of both planktonic and benthic foraminifera shells. The results show that the 7.5 kyr record is lost, the age below 3.27 meters is around 140 kyr ago, and the sedimentation rates range from 0.9 to 5.5 kyr/cm.
Article
Instruments & Instrumentation
Yusuke Shimizu, Yosuke Miyairi, Yusuke Yokoyama
Summary: This study developed an in situ 14C extraction system for extracting in situ 14C from quartz. After improving the design, the system showed low background noise and high extraction efficiency, making it capable of extracting in situ 14C for surface exposure dating.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2023)
Article
Instruments & Instrumentation
Kosuke Ota, Yusuke Yokoyama, Yosuke Miyairi, Shinya Yamamoto, Yunyi Wang, Toshihiro Miyajima
Summary: In this study, the 14C concentration of Lake Kawaguchi was investigated over three years, and a 14C box model was used to estimate groundwater contribution. The results showed seasonal variations in Delta 14C, with a decrease from summer to fall and an increase during winter. Heavy precipitation from Typhoon#19 significantly increased Delta 14C in the lake for one month, potentially due to changes in surface water pathway. The 14C box model demonstrated the potential for semi-quantitatively evaluating groundwater flow in the lake, but further quantitative evaluations of river inflow and other factors are needed to fully understand groundwater dynamics.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2023)
Article
Environmental Sciences
Yusuke Suganuma, Heitaro Kaneda, Martim Mas E. Braga, Takeshige Ishiwa, Takushi Koyama, Jennifer C. Newall, Jun'ichi Okuno, Takashi Obase, Fuyuki Saito, Irina Rogozhina, Jane Lund Andersen, Moto Kawamata, Motohiro Hirabayashi, Nathaniel A. Lifton, Ola Fredin, Jonathan M. Harbor, Arjen P. Stroeven, Ayako Abe-Ouchi
Summary: This study suggests that a regional sea-level highstand triggered rapid thinning of the East Antarctic Ice Sheet during the Holocene. The findings provide important geological records for ice sheet changes and sea-level rise, and contribute to model validation.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
Article
Instruments & Instrumentation
Taisei Hayashi, Kensei Ichiba, Daisuke Nakauchi, Takumi Kato, Noriaki Kawaguchi, Takayuki Yanagida
Summary: In this study, Cr-doped Mg4Ta2O9 single crystals with different doping levels were synthesized using the floating zone method, and their photoluminescence and scintillation properties were evaluated. The results showed that Cr-doped Mg4Ta2O9 single crystals exhibited broad emission bands in the near-infrared region and showed scintillation characteristics within specific wavelength ranges. Additionally, the samples with different Cr doping levels demonstrated different lower detection limits based on the dose rate response function.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
S. Marouf, A. C. Chami, Y. Boudouma
Summary: This study develops a Monte Carlo simulation approach to describe proton-induced secondary electron emission in solids. Theoretical modeling based on the Mott's elastic scattering cross-section and Lindhard's dielectric function was used to calculate the double differential cross-section (DDCS) of excited electrons and describe electron transport in the medium. The results for aluminum show the angular and energy distributions of backscattered electrons for incident protons with energy below 25 keV at normal incidence, and the total electron emission yield also agrees well with available measurements.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
Weipeng Yan, Baojun Duan, Zijian Zhu, Yan Song, Guzhou Song, Jiming Ma, Binkang Li, Yucheng Liu
Summary: This article reports on the scintillation performance of Lithium-doped 2D (PEA)2PbBr4 perovskite single crystals synthesized at room temperature. The crystals exhibit fast decay time, high light yield, and high spatial resolution, making them highly promising for medical diagnostic applications.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
S. B. Vishwakarma, S. K. Dubey, R. L. Dubey, I. Sulania, D. Kanjilal
Summary: Investigations have been conducted on the implanted SiO2 thin film after thermal annealing using various analytical techniques. The results revealed the absence of vacancy defects, variations in vibrational modes and the formation of new structures. The photoluminescence intensity of the annealed SiO2 samples was higher, with a decrease in non-radiative defect centers and an increase in radiative Si:SiO2 interface states. Additionally, the presence of silicon nanoclusters formed after annealing resulted in an additional radiative recombination peak. Furthermore, the formation of new SiOx structures was observed after thermal annealing.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
M. Koshimizu, S. Kurashima, A. Kimura, M. Taguchi
Summary: By observing the scintillation time profiles of CeF3 under irradiations of pulsed beams with different LETs, we found that the initial decay was faster for higher LET, which is consistent with previous studies on other self-activated scintillators. This faster decay at higher LET can be explained by the competition between the scintillation caused by 5d-4f transition of Ce3+ ions and quenching due to the interaction between excited Ce3+ ions close to each other.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
Junjie Shi, Jianhong Hao, Fang Zhang, Qiang Zhao, Bixi Xue, Jieqing Fan, Zhiwei Dong
Summary: This study examined the neutralization process and beam quality of a hydrogen beam by emitting negative hydrogen ions to a hydrogen target. The findings showed that the neutralization efficiency was influenced by variables such as the transport distance, energy, and target gas density. However, the maximal neutralization efficiency was not affected by the density of the target gas or the energy of the negative hydrogen ions.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)