Article
Physics, Condensed Matter
Ilya E. Kolesnikov, Elena Afanaseva, Mikhail A. Kurochkin, Evgenii Yu Kolesnikov, Erkki Lahderanta
Summary: A novel mixed-valent Eu2+/Eu3+-doped MgAl2O4 phosphor is reported as a ratiometric thermal sensor, offering high thermal sensitivity and temperature resolution, making it a promising material for optical thermometry.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Chemistry, Multidisciplinary
Nguyen Thi Quynh Lien, Nguyen Ngoc Trac, Phan Van Do, Ho Van Tuyen
Summary: Europium-doped sodium aluminosilicate glasses were synthesized and their structural and optical properties were investigated. The results showed that the glasses exhibited high emission contribution from Eu3+ ions and the emission spectra could be adjusted by heating in H-2 gas.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2022)
Article
Materials Science, Ceramics
Ho Kim Dan, Nguyen Dinh Trung, T. H. Le, Nguyen Le Thai, Nguyen Minh Ty, Dacheng Zhou, Jianbei Qiu
Summary: This paper investigates the influences of F- ions on the reduction of Eu3+ to Eu2+ and the optical properties of Eu3+/Eu2+-Er3+-Yb3+ co-doped niobate silicate glasses. The study shows that the glasses exhibit visible and upconversion emissions under different excitation conditions, and energy transfer is achieved.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
Yuheng Wu, Yaoyao Yang, Bingfa Liu, Mengzhu Hu, Xiao Min, Yuansheng Wu, Zongjian Liu, Lixin Yu
Summary: The experimental results show that the addition of different network formers can improve the performance of phosphors, while compensating for vacancy defects can harmonize the luminescent color. Therefore, Sr2P2O7: Eu2+-Eu3+ phosphors have the potential to be widely used in various applications.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Elena V. V. Sipina, Dmitry A. A. Spassky, Nataliya R. R. Krutyak, Vladimir A. A. Morozov, Evgenia S. S. Zhukovskaya, Alexei A. A. Belik, Mikhail S. S. Manylov, Bogdan I. I. Lazoryak, Dina V. V. Deyneko
Summary: beta-Ca-3(PO4)(2)-type phosphors Ca9-xMnxEu(PO4)(7) were synthesized and characterized. The abnormal reduction of Eu3+ to Eu2+ in air was observed and confirmed by PL spectra study and XPS. The redistribution of Eu2+/Eu3+ ions among crystal sites and the abnormal quenching of Eu3+ emission were discussed in detail.
Article
Chemistry, Inorganic & Nuclear
Wenke Ruan, Mubiao Xie, Qiaoli Yang, Limin Hu, Kangsheng Su
Summary: A series of single-phase white light-emitting phosphors Ca9Lu(PO4)(7):xEu(2+/3+) were successfully synthesized and their crystallization and optical properties were investigated. By adjusting the valence mixing of Eu2+/Eu3+ ions, the emission colors can change from blue-green to white and eventually to red.
INORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Optics
Pu Fan, Zongjie He, Yuhui Chen, Xiao He, Cong Huang, Qiqi Miao, Qi Zhang, Xiaoguang Liu, Ling Li
Summary: Eu3+/Eu2+ and Sm3+/Sm2+ co-doped LiSrB9O15 phosphors were synthesized by high temperature solid-state method in air atmosphere. The self-reduction phenomenon of Eu3+ to Eu2+ and Sm3+ to Sm2+ was observed in the samples prepared in air atmosphere. The luminescence color of the phosphors can be adjusted by changing the excitation wavelength. Moreover, the near ultraviolet luminescence of LiSrB9O15:Eu phosphor has potential applications in pest control, plant growth promotion, and ultraviolet medical treatment.
JOURNAL OF LUMINESCENCE
(2022)
Article
Chemistry, Physical
So Jeong Park, Min Hee Joo, Ju Young Maeng, Choong Kyun Rhee, Jun -Gill Kang, Youngku Sohn
Summary: Thio-terpyridyl derivatized Au electrodes were used for investigating the electrochemical redox behaviors of Ce3+/Ce4+ and Eu2+/Eu3+ ions. The functionalized gold showed enhanced redox rates and played a significant role in electrochemical CO2 reduction and electrodeposited Eu complexes. The results provide deeper insights into the applications of functionalized gold in lanthanide element treatment/recycling, catalysts, displays, and metal-organic complexes.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Gibin George, Jacob Hayes, Candyce N. Collins, Jason E. Davis, Lei Yu, Yulin Lin, Jianguo Wen, Daryush Ila, Zhiping Luo
Summary: This study investigates the photoluminescence and cathodoluminescence characteristics of rare-earth-doped CaF2 nanoparticles and their composite monoliths with epoxy. The results show that the luminescence intensity increases as the particle size decreases for single-doped particles, but decreases for codoped particles. Additionally, Eu2+- and Tb3+-codoped CaF2 nanoparticles exhibit red emission.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Przemyslaw J. Deren, Dagmara Stefanska, Maciej Ptak, Piotr Wisniewski
Summary: This paper investigates the reduction degree of Eu3+ to Eu2+ and quantum efficiency of Eu2+ emission, revealing the impact of defects such as calcium and oxygen vacancies on the reduction process. By studying samples synthesized in sol-gel and solid-state, and identifying defects using IR measurements, a new method based on magnetic measurements is proposed.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Materials Science, Multidisciplinary
ChaoFei Luo, Ke Liu, WeiWei Ji, Zhan Li, Liangjun Yin, LuYuan Hao, Xin Xu, Simeon Agathopoulos
Summary: A series of apatite phosphors with a general formula of Ca2+xLa8-x(SiO4)(6)O2-0.5x: Eu2+ were successfully synthesized, showing strong green emission at 510 nm with increasing Ca2+ substitution for La3+ ions and the reduction from Eu3+ to Eu2+ ions. XANES results indicated higher Eu2+ content with increasing x value. Rietveld refinement and XANES analyses suggested that the non-equivalent substitution of Ca2+ for La3+ led to a decrease in the number of O2- ions in the crystal, favoring the reduction of Eu3+ to Eu2+.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2021)
Article
Materials Science, Ceramics
Jiachen Chen, Jin Li, Beining Li, Zhuocheng Chen, Xue Bai, Long Zhang, Jin He
Summary: A Eu3+/Eu2+/Tb3+ co-doped sintered nanoporous glass was fabricated by the dipping strategy, which can emit blue, green, and red emissions simultaneously by modifying the thermal treatment temperature. This full-color tuning is attributed to the thermal reduction of Eu3+ to Eu2+ and simultaneous emissions of Eu3+/Eu2+/Tb3+ activators. The densification of the nanoporous glass via sintering effectively enhances the photoluminescence intensity and lifetime of rare earth ions.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Chemistry, Analytical
Yuheng Wu, Kangliang Peng, Shuai Huang, Youjun Zhao, Yakun Deng, Jinshui Ai, Yaoyao Yang, Mengzhu Hu, Xiao Min, Lixin Yu
Summary: A series of phosphors with strong visible light emission and colorful effects were successfully synthesized. By adjusting the relative luminescence intensity of Eu2+ and Eu3+, a colorful emission of phosphors could be achieved. The phosphor could be considered as a potential blue, orange, and red phosphor for white light-emitting diode applications according to the color coordinates of the International Commission on lighting.
Article
Materials Science, Multidisciplinary
Ju Hyun Oh, Hyeon Mi Noh, Jung Hyun Jeong, Sung Heum Park, Byung Chun Choi, Jong Seong Bae
Summary: This paper describes the fabrication of Eu3+-doped SrLaMgTaO6 thin films on a SrTiO3 substrate using PLD, and investigates the structural and photoluminescence properties at different oxygen partial pressures. The study shows that films grown at 100 mTorr exhibit the brightest red emission, and there is a difference in PL intensity between low and high partial pressures. XPS analysis suggests that the PL properties are correlated with the A site doped with Eu3+ ions in the thin films.
Article
Biochemistry & Molecular Biology
Victoria E. Gontcharenko, Mikhail A. Kiskin, Vladimir D. Dolzhenko, Vladislav M. Korshunov, Ilya V. Taydakov, Yury A. Belousov
Summary: The study investigates the luminescent properties of novel lanthanide complexes with different ions, showing that the EuxTb1-xL3 complexes emit both Eu3+ and Tb3+ ions simultaneously, with the luminescence color changing rapidly from green to red upon adding a small amount of Eu3+. A detailed analysis of luminescence decay allowed for determining the radiative lifetimes of Tb3+ and Eu3+ and estimating the rate of excitation energy transfer between these ions.
Article
Transportation
Yoonjung Jang, Donggyun Ku, Seungjae Lee
Summary: In this research, algorithms are studied for detecting pedestrians based on mobile data and GPS base station information, with key variables including travel speed, time, distance, and departure time. Pedestrian groups are categorized into main and access modes based on whether they go to a destination and use transportation vehicles.
TRANSPORTMETRICA A-TRANSPORT SCIENCE
(2023)
Article
Engineering, Marine
Sung Boo Park, Seong Yun Shin, Da Gyun Shin, Hyunjung Park, Kwang Hyo Jung, Sung Bu Suh, Jaeyong Lee, Seung Jae Lee, Hyun Soo Kim
Summary: Wave-ice interactions were experimentally investigated in a three-dimensional wave basin. The transmission coefficient and mean drift velocity of model ice floes were studied under different wave conditions. The results showed that the transmission coefficient increased with wave period and decreased with ice concentration and ice-covered length. The mean ice drift velocity was influenced by wave steepness and had little effect from ice concentration.
Article
Green & Sustainable Science & Technology
Kyuri Baek, Yunseon Choe, Seungjae Lee, Gyehee Lee, Tae-Il Pae
Summary: This study investigates the effects of pilgrimage experiences on meaning and life satisfaction. The research findings suggest that pilgrimage experiences have an impact on meaning in life and life satisfaction, while the search for meaning influences the construction of meaning in life, and meaning in life affects perceived life satisfaction. The moderating role of faith maturity in the relationship between pilgrimage experience and meaning in life is also demonstrated.
Article
Chemistry, Applied
Wonjin Jeon, Ji-Yeon Park, Min-Cheol Kim, Seung-Jae Lee, Deog-Keun Kim
Summary: Various transition metal-based Al2O3 catalysts show significantly different activities in the epoxidation of methyl oleate using H2O2 and O2 as oxidants. The reactivity in H2O2-based epoxidation is proportional to the acidity of the catalysts, while in O2-based epoxidation, it depends on the redox properties of the catalysts and O2 behavior on the catalyst surface. Mo and Cu-based catalysts exhibit outstanding performance with H2O2 and O2 via different reaction pathways. These findings provide valuable insights for designing catalytic reaction processes based on the type of oxidizing agent.
Article
Engineering, Civil
Donggyun Ku, Minje Choi, Haram Oh, Sungyoung Na, Seungjae Lee
Summary: Recently, the need to redefine the modal split model has arisen due to the diversification of transportation systems. This paper proposes a modal split model that reflects the characteristics and preferences of passengers by applying latent class analysis.
TRANSPORTATION RESEARCH RECORD
(2023)
Article
Thermodynamics
Minje Choi, DongGyun Ku, Sion Kim, Juhyeon Kwak, Yoonjung Jang, Doyun Lee, Seungjae Lee
Summary: Personal Mobility (PM) in Seoul, South Korea has gained popularity as an eco-friendly mode of transportation. However, there is a risk of collision when riding PM vehicles on sidewalks. Studies have been conducted to create a safer environment through the use of PM-only lanes and PM-based playgrounds. The implementation of PM-only lanes can lead to a reduction in vehicle kilometers traveled and contribute to environmental benefits. Similarly, creating PM-based playgrounds can promote safer driving through education and data collection. These measures have the potential to activate public transportation usage and reduce energy consumption while ensuring safety and convenience.
Article
Engineering, Civil
Sion Kim, Donggyun Ku, Seungjae Lee
Summary: This study applies percolation theory to analyze the connectivity of transportation networks. It explores the impact of penalties on network travel time by imposing wait times on public transportation nodes. The results demonstrate that penalizing transfer stations has a significant and global effect on travel time, and using a trip frequency weight increases the impact of penalties on medium- or short-timed trips. These findings could inform the development of quarantine policies for controlling public transportation networks.
TRANSPORTATION RESEARCH RECORD
(2023)
Article
Engineering, Civil
Yoonjung Jang, Donggyun Ku, Minje Choi, Dahye Kim, Doyun Lee, Seungjae Lee
Summary: Since being declared a pandemic by the World Health Organization in March 2020, Covid-19 has had a significant impact on daily life. Studies in Korea have shown a decrease in public transportation use, particularly during widespread infection. Additionally, the number of people shopping in commercial districts has significantly decreased. This study analyzes the factors influencing the spread of Covid-19, including transportation demand, revitalization of commercial districts, population movement, and socio-economic indicators, aiming to identify infection factors in different districts of Seoul and provide a foundation for proactive measures to control infectious diseases.
PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-MUNICIPAL ENGINEER
(2023)
Article
Engineering, Civil
Donggyun Ku, Dahye Kim, Seungjae Lee
Summary: This paper aims to clarify the differences in the factors influencing subway traffic behaviour of senior passengers and non-senior passengers during the Covid-19 pandemic in Seoul, South Korea, using big data. The study analyzes the influencing factors of subway use and identifies the factors affecting senior passengers and non-senior passengers through statistical analysis and regression models. The results show that senior passengers are more affected by subway use, with cultural gathering facilities and the number of subway stations being the most influential factors. The regression model has high explanatory power in southern Seoul, where the influencing factors are concentrated.
PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-MUNICIPAL ENGINEER
(2023)
Article
Multidisciplinary Sciences
Ilho Jeong, Minje Choi, Juhyeon Kwak, Donggyun Ku, Seungjae Lee
Summary: This study develops a walkability evaluation system considering the characteristics of a large city and calculates the walkability of Seoul. It finds that considering high betweenness stations and UNA index is essential for evaluating a pedestrian-oriented metropolis. Setting a mobility hub or station at a high-value location in the city center is functionally important for a walkable city.
SCIENTIFIC REPORTS
(2023)
Article
Energy & Fuels
Madiha Bencekri, Donggyun Ku, Doyun Lee, Yee Van Fan, Jiri Jaromir Klemes, Petar Sabev Varbanov, Seungjae Lee
Summary: This study fills the knowledge gaps in evaluating the effectiveness of transport carbon policies and offers a comprehensive comparative overview. Mobility hubs and electric vehicles are considered the most effective policies, while shared bikes and hydrogen vehicles rank lower.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2023)
Proceedings Paper
Robotics
Dong-Uk Seo, Hyungtae Lim, Seungjae Lee, Hyun Myung
Summary: This paper proposes a ground-optimized LiDAR odometry method and examines the impact of ground segmentation on LiDAR SLAM performance. The proposed odometry framework allows easy testing of the effectiveness of ground segmentation algorithms in feature extraction and SLAM performance. The results show the importance of ground segmentation in improving LiDAR SLAM performance.
2022 19TH INTERNATIONAL CONFERENCE ON UBIQUITOUS ROBOTS (UR)
(2022)
Article
Physics, Fluids & Plasmas
Seungjae Lee, Katharina Krischer
Summary: Twisted state is an important and simple form of collective dynamics in oscillatory medium, characterized by inhomogeneous profiles of amplitudes and phase gradients. In this study, we investigate a non-trivial twisted state in a system of nonlocally coupled Stuart-Landau oscillators using various methods including linear stability analysis, Lyapunov exponents, and covariant Lyapunov vectors. We show that the non-trivial twisted state is robust and can be born or annihilated in saddle-node bifurcations and change stability in Hopf bifurcations.
Review
Automation & Control Systems
Mark W. Mueller, Seung Jae Lee, Raffaello D'Andrea
Summary: The article reviews recent progress in the design and control of drones, discussing design objectives, physical scaling laws, and the integration of sensing with control and planning. It also compares different vehicle morphologies and considers the effects of multivehicle teams.
ANNUAL REVIEW OF CONTROL ROBOTICS AND AUTONOMOUS SYSTEMS
(2022)
Article
Psychology, Social
David S. Lee, Tao Jiang, Jennifer Crocker, Baldwin M. Way
Summary: The study found a positive correlation between social media use and physical health indicators, including higher levels of chronic inflammation markers, more somatic symptoms, and more frequent doctor visits.
CYBERPSYCHOLOGY BEHAVIOR AND SOCIAL NETWORKING
(2022)
Review
Chemistry, Multidisciplinary
Dan He, Yawen Li, Fuwen Zhao, Yuze Lin
Summary: High trap density in organic solar cells leads to localized charge carriers and reduced carrier lifetime, limiting device efficiency. This feature article summarizes the recent advances of trap suppression by material design and device engineering.
CHEMICAL COMMUNICATIONS
(2024)
Review
Chemistry, Multidisciplinary
Olivier Monfort, Arshitha Madhusudhan, Martin Motola
Summary: This article presents the advantages of coupling photocatalysis and Fenton-based processes for environmental remediation and discusses their synergy. It critically examines the simultaneous triggering of these two processes and provides insights into research approaches. The study aims to enhance understanding of this complex process and highlight the potential integration of new catalysts in current wastewater treatment technology.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Manideepa Dhar, Chittaranjan Mishra, Avijit Das, Uttam Manna
Summary: An approach of 'polymerization of monomers in its aggregated form' has been introduced to tailor the water wettability of fibrous and porous substrates, achieving hydrophobicity to superhydrophobicity transition, as well as patterned wettability. This facile chemical method provides a durable coating with adjustable and patterned wettability for various potential applications.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Saswat Ranjan Bhoi, Chhanda Debnath, Shikha Gandhi
Summary: In this article, a novel catalytic reaction using Pd(0) and Bronsted acid is reported for the synthesis of biologically important imidazolidinone-fused N-heterocycles through redox-neutral intramolecular N-allylation of indoles and pyrroles with alkynes. This atom-economical method is applicable to a wide range of substrates and eliminates the need for leaving groups or oxidizing agents commonly used in traditional allylation reactions.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Longkun Chen, Mingshuai Zhang, Meichen Liu, Zhuoyuan Liu, Yuetong Qiu, Zhilai Zhang, Fuchao Yu, Jiuzhong Huang
Summary: In this study, an efficient Rh(III)-catalyzed selective mono- and dual-C-H bond functionalization/cyclization with iodonium ylide as the sole coupling partner was demonstrated. Fused benzodiazepine skeletons were obtained in excellent yields, providing an improved approach to dual C-H unsymmetrical functionalization.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Alice Kennett, Sven Epple, Gabriella van der Valk, Irene Georgiou, Evelyne Gout, Romain R. Vives, Angela J. Russell
Summary: This study presents the design and synthesis of sulfated disaccharide inhibitors based on IdoA(2S)-GlcNS(6S), which showed potent inhibition of Sulf-2. The results suggest that IdoA(2S)-GlcNS(6S) is the shortest fragment size required for effective inhibition of Sulfs, and a trisulfated disaccharide is identified as the minimal fragment size of heparan sulfate for effective endosulfatase inhibition.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Mauro Garbini, Andrea Brunetti, Riccardo Pedrazzani, Magda Monari, Massimo Marcaccio, Giulio Bertuzzi, Marco Bandini
Summary: The self-adaptability of galvanostatic electrolysis was found to be helpful in a multistage chemo- and diastereoselective electrochemically promoted cyclodimerization of chalcones. Through a series of reductive events, densely functionalized cyclopentanes with five contiguous stereocenters were obtained (25 examples, yields up to 95%, dr values up to >20:1). Further experimental and electrochemical investigations indicated the crucial role of dynamic kinetic resolution of the aldol intermediate in the reaction mechanism.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Dhananjay S. Nipate, Neha Meena, Prakash N. Swami, Krishnan Rangan, Anil Kumar
Summary: In this study, the synthesis of functionalized benzo[a]phenazines and indazolo[2,3-a]quinolines was achieved through Rh(III)-catalyzed oxidative annulation of 2-arylquinoxalines and 2-aryl-2H-indazoles with allyl alcohols. The method showed a wide substrate scope, excellent functional group tolerance, good to high yields of annulated products, and the capability for scaled-up synthesis. A tentative mechanism of the annulation reaction was proposed based on a preliminary mechanistic investigation.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Ruonan Zhang, Abudukadi Tudi, Xia Yang, Xuping Wang, Zhihua Yang, Shujuan Han, Shilie Pan
Summary: A new lead tellurium borate material with a unique fundamental building block [B4O10] was synthesized and found to exhibit high birefringence. The structure-property relationship was discussed using first-principles calculations.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Amresh Kumar Singh, Baishali Thakurta, Anupam Giri, Monalisa Pal
Summary: This study introduces three key concepts for the quick synthesis of large-scale high-quality 2D materials films and their utilization in device fabrication.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Reina Hagiwara, Shun Nishimura, Kosuke Okeyoshi
Summary: A copolymer-conjugated nanocatalytic system has been developed to improve electron transfer and enhance photoinduced H2 generation.
CHEMICAL COMMUNICATIONS
(2024)
