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Thermally activated delayed fluorescence carbazole-triazine dendrimer with bulky substituents

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Aggregate 2024年第1期5卷 236-243页

作者： Hiroki Ikebe Kohei Nakao Eri Hisamura Minori Furukori Yasuo Nakayama Takuya Hosokai Minlang Yang Guanting Liu Takuma Yasuda Ken Albrecht Interdisciplinary Graduate School of Engineering sciences Kyushu UniversityFukuokaJapan Institute for Materials Chemistry and Engineering Kyushu UniversityKasugaJapan Department of Pure and Applied Chemistry Graduate School of Science and TechnologyTokyo University of ScienceNodaChibaJapan National Metrology Institute of japan(NMIJ) National Institute of Advanced Industrial Science and Technology(AIST)TsukubaIbarakiJapan Institute for Advanced Study Kyushu UniversityNishi-kuFukuokaJapan

Carbazole-triazine dendrimers with a bulky terminal substituent were synthesized,and the thermally activated delayed fluorescence(TADF)property was *** to unsubstituted carbazole dendrimers,dendrimers with bulky terminal substituents showed comparable to better photoluminescence quantum yields(PLQY)in neat ***(PF)-substituted dendrimers showed the highest PLQY of 81%,a smallΔEst of 0.06 eV,and the fastest reverse intersystem crossing(RISC)rate of∼1×10^(5 )s^(−1) compared to other *** measurements of dendrimers and dendrons(fragments)indicate that the close proximity of the triplet energy of phenylfluorene-substituted carbazole dendrons(^(3)LE)to that of phenylfluorene-substituted dendrimers(^(1)CT,^(3)CT)contributes to RISC promotion and improves TADF *** modification fine-tunes the energy level and suppresses intermolecular interactions,and this study provides a guideline for designing efficient solution-processable and non-doped TADF materials.

关键词： dendrimer OLED TADF 1 INTRODUCTION Thermally activated delayed fluorescence(TADF)materials which are inexpensive and highly efficient alternatives to fluorescent

Oxidation behavior and improvement in nonflammability of LPSO-type Mg–Zn–Y–Sr alloy

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Journal of Magnesium and Alloys 2024年第2期12卷 742-749页

作者： Shin-ichi Inoue Kazumasa Iwanaga Yoshihito Kawamura Magnesium Research Center Kumamoto University2-39-1 KurokamiChuo-kuKumamoto 860-8555Japan Department of Materials science Graduate School of Science and TechnologyKumamoto University2-39-1 KurokamiChuo-kuKumamoto 860-8555Japan

Mg_(97)Zn_(1)Y_(2)alloys with high ignition temperatures were developed by adding *** addition of Sr resulted in the formation of a uniform and thin Y_(2)O_(3)***–Zn–Y alloys containing at least 0.25 at.%Sr exhibited ignition temperatures of 1270–1320 *** a result of EDS measurement,Sr was found to be concentrated in the Y_(2)O_(3)*** addition,a mixed film of MgO and Sr O formed on the outer layer in the 1.5 at.%Sr-containing Mg_(97)Zn_(1)Y_(2)*** findings suggest that the uniform and thin Y_(2)O_(3)film that maintains high soundness at high temperatures was formed owing to valence control and the formation of a protective outer oxide film.

关键词： Magnesium alloy Yttrium Strontium High-temperature oxidation Nonflammability

Device-measured physical activity and sedentary time in the Nordic countries:A scoping review of population-based studies

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Journal of Sport and Health science 2024年第5期13卷 650-660页

作者： Ing-Mari Dohrn Jakob Tarp Jostein Steene-Johannessen Tommi Vasankari Maria Hagströmer Division of Physiotherapy Department of NeurobiologyCare Sciences and SocietyKarolinska Institutet14183 HuddingeSweden Department of Sports Medicine Norwegian School of Sports Sciences0806 OsloNorway UKK Institute for Health promotion Research 33500 TampereFinland Faculty of Medicine and Health Technology Tampere University33100 TampereFinland Academic Primary Health Care Centre Region Stockholm13365 StockholmSweden

Purpose:The purpose of this scoping review was to summarize and describe the methodology and results from population-based studies of physical activity and sedentary time measured with devices in the Nordic countries(Denmark,Finland,Iceland,Norway,and Sweden)and published in 2000 or ***:A systematic search was carried out in PubMed and Web of science in June 2023 using predefined search ***:Fourteen unique research projects or surveillance studies were ***,2 surveillance studies published by national agencies were included,resulting in a total of 16 studies for *** surveillance systems exist in Finland and Norway,with regular survey waves in school-aged children/adolescents and *** Denmark,recent nationally representative data have been collected in school children *** far,Sweden has no regular national surveillance system using device-based data *** studies were found from *** first study was conducted in 2001 and the most recent in 2022,with most data collected from 2016 to *** studies included children/adole scents 6-18 years,no study included *** total 11 studies included adults,of which 8 also covered older *** study focused specifically on older *** analytical sample size ranged from 205 to 27,*** methodology is presented,such as information on sampling strategy,device type and placement,wear protocols,and physical activity classification *** of physical activity and sedentary time in children/adolescents,adults,and older adults across the Nordic countries are ***:A growing implementation of device-based population surveillance of physical activity and sedentary behavior in the Nordic countries has been *** variety of devices,placement,and data procedures both within and between the Nordic countries highlights the challenges when it comes to comparing study outcomes as well as the need for more standa

关键词： Accelerometer Light intensity Moderate-vigorous intensity Surveillance Wearable devices

japanese Sign Language Recognition by Combining Joint Skeleton-Based Handcrafted and Pixel-Based Deep Learning Features with Machine Learning Classification

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Computer Modeling in Engineering & sciences 2024年第6期139卷 2605-2625页

作者： Jungpil Shin Md.Al Mehedi Hasan Abu Saleh Musa Miah Kota Suzuki Koki Hirooka School of Computer science and Engineering The University of AizuAizuwakamatsu965-8580Japan Department of Computer science&Engineering Rajshahi University of Engineering&TechnologyRajshahi6204Bangladesh

Sign language recognition is vital for enhancing communication accessibility among the Deaf and hard-of-hearing *** japan,approximately 360,000 individualswith hearing and speech disabilities rely on japanese Sign Language(JSL)for ***,existing JSL recognition systems have faced significant performance limitations due to inherent *** response to these challenges,we present a novel JSL recognition system that employs a strategic fusion approach,combining joint skeleton-based handcrafted features and pixel-based deep learning *** system incorporates two distinct streams:the first stream extracts crucial handcrafted features,emphasizing the capture of hand and body movements within JSL ***,a deep learning-based transfer learning stream captures hierarchical representations of JSL gestures in the second ***,we concatenated the critical information of the first stream and the hierarchy of the second stream features to produce the multiple levels of the fusion features,aiming to create a comprehensive representation of the JSL *** reducing the dimensionality of the feature,a feature selection approach and a kernel-based support vector machine(SVM)were used for the *** assess the effectiveness of our approach,we conducted extensive experiments on our Lab JSL dataset and a publicly available Arabic sign language(ArSL)*** results unequivocally demonstrate that our fusion approach significantly enhances JSL recognition accuracy and robustness compared to individual feature sets or traditional recognition methods.

关键词： japanese Sign Language(JSL) hand gesture recognition geometric feature distance feature angle feature GoogleNet

Evaluating mechanism of banana pseudo-stem retting using seawater:A cost-effective surface pre-treatment approach

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Journal of Bioresources and Bioproducts 2024年第3期9卷 322-335页

作者： Prince Hotor Ahmed H.Hassanin Osbert Akatwijuka Mohamed A.H.Gepreel Mitsuo Yamamoto Yukie Saito Ahmed Abdel-Mawgood Egypt-japan University of science and Technology Biotechnology ProgramAlexandria GovernorateNew Borg Al Arab 21934Egypt Alexandria University Department of Textile EngineeringAlexandria GovernorateBab Sharqi 5424041Egypt Egypt-japan University of science and Technology Material Science and EngineeringAlexandria GovernorateNew Borg Al Arab 21934Egypt Graduate School of Agricultural and Life sciences The University of TokyoBunkyo-KuTokyo 113-8657Japan

Retting has been employed to extract natural fibers from agricultural wastes as a biological and cost-effective approach for *** its global abundance,banana pseudo-stem is a promising agro-waste for lignocellulosic fiber *** this study,fibers were extracted from the pseudo-stems after being pre-treated under four conditions using seawater at room temperature for up to 35 d Bacterial isolation from the fresh seawater sample and screening for ligninolytic ability were *** load as well as laccase and manganese peroxidase enzyme activity profile assay during the retting duration were *** transform infrared(FT-IR)and X-day diffraction(XRD)analyses were also examined for both pre-treated and untreated extracted *** results shows that six out of the eight bacterial isolates had the ability to degrade *** treatments(Raw stem+Raw seawater)and(Autoclaved stem+Raw seawater)recorded the highest viable bacterial load of 9.24×102 and 4.46×102 CFU,respectively,on the 14th day of the retting ***,the highest laccase and manganese peroxidase enzymes activity was recorded for(Raw stem+Raw seawater)and(Autoclaved stem+Raw seawater)treatments in the second to the third *** FT-IR spectra of the pre-treated fibers revealed relative reductions in peaks attributed to polysaccharides and other amorphous substances for all retting *** XRD diffractogram revealed that the crystallinity index(CI)of pre-treated fibers increased in all seawater retting treatment ***,the CI for fibers pre-treated under enzymatic conditions were enhanced even after five *** analysis for selected bacterial isolates showed homology to sequences of Bacillus velezensis,Shewanella sp.L8–5,and Citrobacter amalonaticus and Bacillus subtilis j8 *** these findings,it was suggested that physical,biological,and chemical actions were collectively involved in the seawater retting process of banana ps

关键词： Seawater retting Banana pseudo-stem Natural fiber Enzyme activity Colony forming unit

Metal-to-insulator transitions in 3d-band correlated oxides containing Fe compositions

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 48-59页

作者： Yiping Yu Yuchen Cui Jiangang He Wei Mao Jikun Chen Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083China School of Materials science and Engineering University of Science and Technology BeijingBeijing 100083China Institute of Industrial science The University of Tokyo4-6-1 KomabaMeguro-kuTokyo 153-8505Japan

Metal-to-insulator transitions (MITs),which are achieved in 3d-band correlated transitional metal oxides,trigger abrupt variations in electrical,optical,and/or magnetic properties beyond those of conventional *** such material families,iron(Fe:3d^(6)4s^(2))-containing oxides pique interest owing to their widely tunable MIT properties,which are associated with the various valence states of *** potential electronic applications also show promise,given the large abundance of Fe on *** MIT properties triggered by critical temperature (TMIT) were reported for ReFe_(2)O_(4)(Fe^(2.5+)),ReBaFe_(2)O_(5)(Fe^(2.5+)),Fe_(3)O_(4)(Fe^(2.67+)),Re_(1/3)Sr_(2/3)FeO_(3)(Fe^(3.67+)),Re Cu_(3)Fe_(4)O_(12)(Fe^(3.75+)),and Ca_(1-x)Sr_(x)FeO_(3)(Fe^(4+))(where Re represents rare-earth elements).The common feature of MITs of these Fe-containing oxides is that they are usually accompanied by charge ordering transitions or disproportionation associated with the valence states of ***,we review the material family of Fe-containing MIT oxides,their MIT functionalities,and their respective *** the perspective of potentially correlated electronic applications,the tunability of the TMITand its resultant resistive change in Fe-containing oxides are summarized and further compared with those of other materials exhibiting MIT *** particular,we highlight the abrupt MIT and wide tunability of TMITof Fe-containing quadruple perovskites,such as Re ***,their effective material synthesis still needs to be further explored to cater to potential applications.

关键词： metal-to-insulator transitions Fe-containing oxides charge ordering charge disproportionation

Dynamic Hand Gesture-Based Person Identification Using Leap Motion and Machine Learning Approaches

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Computers, Materials & Continua 2024年第4期79卷 1205-1222页

作者： Jungpil Shin Md.AlMehedi Hasan Md.Maniruzzaman Taiki Watanabe Issei Jozume School of Computer science and Engineering The University of AizuAizuwakamatsuFukushima965-8580Japan Department of Computer science&Engineering Rajshahi University of Engineering&TechnologyRajshahi6204Bangladesh

Person identification is one of the most vital tasks for network security. People are more concerned about theirsecurity due to traditional passwords becoming weaker or leaking in various attacks. In recent decades, fingerprintsand faces have been widely used for person identification, which has the risk of information leakage as a resultof reproducing fingers or faces by taking a snapshot. Recently, people have focused on creating an identifiablepattern, which will not be reproducible falsely by capturing psychological and behavioral information of a personusing vision and sensor-based techniques. In existing studies, most of the researchers used very complex patternsin this direction, which need special training and attention to remember the patterns and failed to capturethe psychological and behavioral information of a person properly. To overcome these problems, this researchdevised a novel dynamic hand gesture-based person identification system using a Leap Motion sensor. Thisstudy developed two hand gesture-based pattern datasets for performing the experiments, which contained morethan 500 samples, collected from 25 subjects. Various static and dynamic features were extracted from the handgeometry. Randomforest was used to measure feature importance using the Gini Index. Finally, the support vectormachinewas implemented for person identification and evaluate its performance using identification accuracy. Theexperimental results showed that the proposed system produced an identification accuracy of 99.8% for arbitraryhand gesture-based patterns and 99.6% for the same dynamic hand gesture-based patterns. This result indicatedthat the proposed system can be used for person identification in the field of security.

关键词： Person identification leap motion hand gesture random forest support vector machine

Novel design of a compact tunable dual band wireless power transfer(TDB-WPT)system for multiple WPT applications

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Frontiers of Information Technology & Electronic Engineering 2024年第4期25卷 616-628页

作者： Hany A.ATALLAH Rasha Hussein AHMED Adel B.ABDEL-RAHMAN Department of Communications and Electronics Faculty of EngineeringSouth Valley UniversityQena 83523Egypt Egypt-japan University of science and Technology Alexandria 21934Egypt

In this study we present the design and realization of a tunable dual band wireless power transfer(TDB-WPT)coupled resonator *** frequency response of the tunable band can be controlled using a surface-mounted *** transmitter(Tx)and the receiver(Rx)circuits are *** top layer contains a feed line with an impedance of 50Ω.Two identical half rings defected ground structures(HR-DGSs)are loaded on the bottom using a varactor *** propose a solution for restricted WPT systems working at a single band application according to the operating *** effects of geometry,orientation,relative distance,and misalignments on the coupling coefficients were *** validate the simulation results,the proposed TDB-WPT system was fabricated and *** system occupied a space of 40 mm×40 *** can deliver power to the receiver with an average coupling efficiency of 98%at the tuned band from 817 to 1018 MHz and an efficiency of 95%at a fixed band of 1.6 GHz at a significant transmission distance of 22 *** results of the measurements accorded well with those of an equivalent model and the simulation.

关键词： Defected ground structure(DGS) Surface-mounted Tunable dual band wireless power transfer(TDB-WPT) Varactor

A review on ultra-small undoped MoS_(2) as advanced catalysts for renewable fuel production

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Carbon Energy 2024年第2期6卷 92-112页

作者： Guoping Liu Lingling Ding Yuxuan Meng Ahmad Ali Guifu Zuo Xianguang Meng Kun Chang Oi Lun Li Jinhua Ye Hebei Provincial Laboratory of Inorganic Nonmetallic Materials College of Materials Science and EngineeringNorth China University of Science and TechnologyTangshanChina College of Materials science and Technology Nanjing University of Aeronautics and AstronauticsNanjingChina School of Materials science and Engineering Pusan National UniversityBusanKorea International Center for Materials Nanoarchitectonics(WPIMANA) National Institute for Materials Science(NIMS)1-1 NamikiTsukubaIbarakiJapan

Molybdenum disulfide(MoS_(2))has garnered significant attention in the field of catalysis due to the high density of active sites in its unique two-dimensional(2D)structure,which could be developed into numerous high-performance *** synthesis of ultra-small MoS2 particles(<10 nm)is highly desired in various experimental *** ultra-small structure could often lead to a distinct S-Mo coordination state and nonstoichiometric composition in MoSx,minimizing in-plane active sites of the 2D structure and making it probable to regulate the atomic and electronic structure of its intrinsic active sites on a large extent,especially in MoSx *** article summarizes the recent progress of catalysis over ultra-small undoped MoS_(2) particles for renewable fuel *** a systematic review of their synthesis,structural,and spectral characteristics,as well as the relationship between their catalytic performance and inherent defects,we aim to provide insights into catalysis over this matrix that may potentially enable advancement in the development of high-performance MoS_(2)-based catalysts for sustainable energy generation in the future.

关键词： applications catalytic MoS_(2) structure synthesis