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Tetradentate Pt(Ⅱ)complex as a singlet exciton sensitizing host for highly efficient green fluorescent organic light-emitting diodes

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Science China Materials 2024年第8期67卷 2618-2627页

作者： Unhyeok Jo Seung chan Kim chan hee Ryu Kang Mun lee Jae-Min Kim Jun Yeob lee School of Chemical Engineering Sungkyunkwan University2066Seobu-roJangan-guSuwon-siGyeonggi-do 16419Republic of Korea Department of Chemistry Institute for Molecular Science and Fusion TechnologyKangwon National UniversityChuncheonGangwon 24341Republic of Korea Department of Advanced Materials Engineering Chung-Ang University4726Seodong-daeroDaedeok-myeonAnseong-siGyeonggi-do 17546Republic of Korea SKKU Advanced Institute of Nano Technology Sungkyunkwan University2066Seobu-roJangan-guSuwonGyeonggi 16419Republic of Korea SKKU Institute of Energy Science and Technology Sungkyunkwan University2066Seobu-roJangan-guSuwonGyeonggi 16419Republic of Korea

Efficient green fluorescent organic light-emitting diodes were designed with a phosphorescent metal complex as a singlet exciton sensitizing host(SESH)for achieving high efficiency and low efficiency roll-off through exciton and polaron *** Pt(Ⅱ)complex(Pt-Trz)possessing a tetradentate ligand with a bulky blocking group not only suppresses the severe formation of excimer or dimer itself but also transfers radiative excitons to fluorescent dopant *** SESH assisted fluorescence(SESHF)device with Pt-Trz as the host exhibits the maximum external quantum efficiency of 13.3%and a lower efficiency roll-off compared with exciplex host device which is a general approach for harvesting triplet *** exciton dynamics modeling unravels that the SESHF device effectively utilizes triplet excitons in the host by intersystem crossing and resonance energy transfer from the triplet state of the host to the singlet state of the terminal *** quenching rates of the SESHF device are reduced by 11 times for triplet-triplet annihilation and 1.8 times for tripletpolaron annihilation compared with the exciplex device,which demonstrates that Pt-Trz could be a platform to be used as an efficient host for fluorophores.

关键词： singlet annihilation polaron

Research on Cavitation Characteristics and Influencing Factors of Herringbone Gear Pump

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2917-2946页

作者： Jinlong Yang Kwang-hee lee Chul-hee lee Department of Mechanical Engineering of Inha University Incheon22212South Korea

Cavitation is a common issue in pumps,causing a decrease in pump head,a fall in volumetric efficiency,and an intensification of outlet flow *** is one of the main hazards that affect the regular operation of the *** on pump cavitation mainly focuses on mixed flow pumps,jet pumps,external spur gear pumps,***,there are few cavitation studies on external herringbone gear *** addition,pumps with different working principles significantly differ in the flow and complexity of the internal flow ***,it is urgent to study the cavitation characteristics of external herringbone gear *** with experimentalmethods,visual research and cavitation area identification are achieved through computation fluid dynamic(CFD),and changing the boundary conditions and shape of the gear rotor is *** simulation yields a head error of only 0.003%under different grid numbers,and the deviation between experimental and simulation results is less than 5%.The study revealed that cavitation causes flow pulsation at the outlet,and the cavitation serious area is mainly distributed in the meshing gap and meshing *** can be inhibited by reducing the speed,increasing the inlet pressure,and changing the helix angle can be *** example,when the inlet pressure is 5 bar,the maximumgas volume fraction in themeshing area is less than 50%.These results provide a reference for optimizing the design and finding the optimal design parameters to reduce or eliminate cavitation.

关键词： Herringbone gear pump cavitation rotating speed inlet pressure helix angle TwinMesh

Enhancing Identity Protection in Metaverse-Based Psychological Counseling System

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Computers, Materials & Continua 2024年第1期78卷 617-632页

作者： Jun lee Hanna lee Seong chan lee Hyun Kwon Department of Game Software Hoseo UniversityAsan-si31499Korea Yatav Enter Seoul04799Korea Department of Artificial Intelligence and Data Science Korea Military AcademySeoul01805Korea

Non-face-to-face psychological counseling systems rely on network technologies to anonymize information regard-ing client ***,these systems often face challenges concerning voice data leaks and the suboptimal communication of the client’s non-verbal expressions,such as facial cues,to the *** study proposes a metaverse-based psychological counseling system designed to enhance client identity protection while ensuring efficient information delivery to counselors during non-face-to-face *** proposed systemincorporates a voicemodulation function that instantlymodifies/masks the client’s voice to safeguard their ***,it employs real-time client facial expression recognition using an ensemble of decision trees to mirror the client’s non-verbal expressions through their avatar in the metaverse *** system is adaptable for use on personal computers and smartphones,offering users the flexibility to access metaverse-based psychological counseling across diverse *** performance evaluation of the proposed system confirmed that the voice modulation and real-time facial expression replication consistently achieve an average speed of 48.32 frames per second or higher,even when tested on the least powerful smartphone ***,a total of 550 actual psychological counseling sessions were conducted,and the average satisfaction rating reached 4.46 on a 5-point *** indicates that clients experienced improved identity protection compared to conventional non-face-to-face metaverse counseling ***,the counselor successfully addressed the challenge of conveying non-verbal cues from clients who typically struggled with non-face-to-face psychological *** proposed systemholds significant potential for applications in interactive discussions and educational activities in the metaverse.

关键词： Metaverse counseling system face tracking identity protection

Tetradentate Pt(II) complex as a singlet exciton sensitizing host for highly efficient green fluorescent organic light-emitting diodes

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Science China Materials 2024年

作者： Unhyeok Jo Seung chan Kim chan hee Ryu Kang Mun lee Jae-Min Kim Jun Yeob lee School of Chemical Engineering Sungkyunkwan University 2066 Seobu-ro Jangan-gu Suwon-si Department of Chemistry Institute for Molecular Science and Fusion Technology Kangwon National University Chuncheon Department of Advanced Materials Engineering Chung-Ang University 4726 Seodong-daero Daedeok-myeon Anseong-si SKKU Advanced Institute of Nano Technology Sungkyunkwan University 2066 Seobu-ro Jangan-gu SKKU Institute of Energy Science and Technology Sungkyunkwan University 2066 Seobu-ro Jangan-gu

Efficient green fluorescent organic light-emitting diodes were designed with a phosphorescent metal complex as a singlet exciton sensitizing host (SESH) for achieving high efficiency and low efficiency roll-off through exciton and polaron management. Tetradentate Pt(II) complex (Pt-Trz)possessing a tetradentate ligand with a bulky blocking group not only suppresses the severe formation of excimer or dimer itself but also transfers radiative excitons to fluorescent dopant effectively. The SESH assisted fluorescence (SESHF) device with Pt-Trz as the host exhibits the maximum external quantum efficiency of 13.3%and a lower efficiency roll-off compared with exciplex host device which is a general approach for harvesting triplet excitons. Numerical exciton dynamics modeling unravels that the SESHF device effectively utilizes triplet excitons in the host by intersystem crossing and resonance energy transfer from the triplet state of the host to the singlet state of the terminal emitter. Bimolecular quenching rates of the SESHF device are reduced by 11 times for triplet-triplet annihilation and 1.8 times for tripletpolaron annihilation compared with the exciplex device, which demonstrates that Pt-Trz could be a platform to be used as an efficient host for fluorophores.

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Construction of a High‑Performance Composite Solid Electrolyte Through In‑Situ Polymerization within a Self‑Supported Porous Garnet Framework

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Nano-Micro Letters 2024年第5期16卷 56-70页

作者： An‑Giang Nguyen Min‑Ho lee Jaekook Kim chan‑Jin Park Department of Materials Science and Engineering Chonnam National University77 Yongbong‑roBuk‑guGwangju 61186South Korea

Composite solid electrolytes(CSEs)have emerged as promising candidates for safe and high-energy–density solid-state lithium metal batteries(SSLMBs).However,concurrently achieving exceptional ionic conductivity and interface compatibility between the electrolyte and electrode presents a significant challenge in the development of high-performance CSEs for *** overcome these challenges,we present a method involving the in-situ polymerization of a monomer within a self-supported porous Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZT)to produce the *** synergy of the continuous conductive LLZT network,well-organized polymer,and their interface can enhance the ionic conductivity of the CSE at room ***,the in-situ polymerization process can also con-struct the integration and compatibility of the solid electrolyte–solid electrode *** synthesized CSE exhibited a high ionic conductivity of 1.117 mS cm^(-1),a significant lithium transference number of 0.627,and exhibited electrochemical stability up to 5.06 V ***/Li+at 30℃.Moreover,the Li|CSE|LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cell delivered a discharge capacity of 105.1 mAh g^(-1) after 400 cycles at 0.5 C and 30℃,corresponding to a capacity retention of 61%.This methodology could be extended to a variety of ceramic,polymer electrolytes,or battery systems,thereby offering a viable strategy to improve the electrochemical properties of CSEs for high-energy–density SSLMBs.

关键词： Scalable tape-casting method Self-supported porous Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12) Composite solid electrolyte LiF-and B-rich interphase layers

In situ infrared, Raman and X-ray spectroscopy for the mechanistic understanding of hydrogen evolution reaction

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Journal of Energy Chemistry 2024年第3期90卷 632-651,I0014页

作者： Andi Haryanto Kyounghoon Jung chan Woo lee Dong-Wan Kim Department of Chemistry Kookmin UniversitySeoul 02707Republic of Korea School of Civil Environmental and Architectural EngineeringKorea UniversitySeoul 02841Republic of Korea

Hydrogen production by water reduction reactions has received considerable attention because hydrogen is considered a clean-energy carrier,key for a sustainable energy *** methods have been widely used to study the reaction mechanism of the hydrogen evolution reaction(HER),but the calculation results need to be supported by experimental results and direct evidence to confirm the mechanistic *** this review,we discuss the fundamental principles of the in situ spectroscopic strategy and a theoretical model for a mechanistic understanding of the *** addition,we investigate recent studies by in situ Fourier transform infrared(FTIR),Raman spectroscopy,and X-ray absorption spectroscopy(XAS) and cover new findings that occur at the catalyst-electrolyte interface during *** spectroscopic strategies provide practical ways to elucidate catalyst phase,reaction intermediate,catalyst-electrolyte interface,intermediate binding energy,metal valency state,and coordination environment during HER.

关键词： Hydrogen evolution reaction Infrared spectroscopy Raman spectroscopy X-ray absorption spectroscopy Reaction mechanism

Impact of statin usage patterns on outcomes after percutaneous coronary in-tervention in acute myocardial infarction：Korea Working Group on Myocar-dial Infarction registry （KorMI） study

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Journal of Geriatric Cardiology 2014年第2期11卷 93-99页

作者： chan-hee lee Sang-hee lee Jong-Seon Park Young-Jo Kim Kee-Sik Kim Shung-Chull Chae Hyo-Soo Kim Dong-Ju Choi Myeong-chan Cho Seung-Woon Rha Myung-Ho Jeong Department of Cardiology Yeungnam University Hospital 170 Hyeonchung-ro Nam-gu Daegu 705-717 South Korea Department of Internal Medicine Daegu Catholic University Hospital 33 Duryugongwon-ro 17-gil Nam-gu Daegu 705-718 South Korea Department of Internal Medicine Kyungpook National University Hospital 130 Dongdeok-ro Jung-gu Daegu 700-721 South Korea Department of Internal Medicine Seoul National University Hospital 101 Daehak-ro Jongno-gu Seoul 110-744 South Korea Department of Internal Medicine Seoul National University Bundang Hospital 82 Gumi-ro 173-gil Bundang-gu Seongnam 463-707 South Korea Department of Internal Medicine Chungbuk National University Hospital 776 1sunhwan-ro Heungdeok-gu Cheongju 361-711 South Korea Department of Internal Medicine Korea University Guro Hospital 148 Gurodong-ro Guro-gu Seoul 152-703 South Korea Department of Internal Medicine Chonnam National University Hospital 42 Jebong-ro Dong-gu Gwangju 501-757 South Korea

在心肌的梗塞(STEMI ) 是的尖锐圣片断举起以后的 statin 使用的 BackgroundThe 利益然而，很好证实预定 statin 管理的影响没被阐明。这研究的目的在经皮的冠的干预(一种总线标准) 以后集中了于早临床的结果学习包括了的心肌的梗塞登记... 详细信息

在心肌的梗塞(STEMI ) 是的尖锐圣片断举起以后的 statin 使用的 BackgroundThe 利益然而，很好证实预定 statin 管理的影响没被阐明。这研究的目的在经皮的冠的干预(一种总线标准) 以后集中了于早临床的结果学习包括了的心肌的梗塞登记(KorMI ) 上的朝鲜工作组的 .MethodsThis 分析 3,584 个 STEMI 病人(吝啬的年龄， 63 ±；13 年；男性， 2,684， 74.9%) 从 2008 年 1 月经历一种总线标准到 2009 年 6 月。主要不利心脏的事件的率(向：所有原因死亡，周期性的 MI，和目标损害 revascularization ) 在根据 statin 治疗预定组织的病人之中被比较：我，在期间并且在住院以后(n = 2,653， 74%) ；II，仅仅在住院期间(n = 309， 8.6%) ；III，仅仅在分泌物以后(n = 157， 4.4%) ；并且 IV，没有 statin 治疗(n = 465， 13%) 。吝啬的后续持续时间是 234 ±；statin 的 113 个 *** 因素在住院期间使用包括的优先的 statin 使用，多重 diseased 容器，在心肌的梗塞流动等级 III 的最后的 thrombolysis，和低密度的脂蛋白胆固醇水平。在 6 月的后续，组 III 和 IV 有最高的向率(2.3% ， 3.9% ， 5.1% ，和 4.9% 为组 I-IV，分别地 P = 0.004 ) 。在为 confounders 调整以后，组 II-IV 比组有更高的向风险我[危险比率(HR ) ：3.20， 95% 信心间隔(95%CI ) ：1.31-7.86， P = 0.011；HR：3.84， 95%CI：1.47-10.02， P = 0.006；并且 HR：3.17， 95%CI：1.59-6.40， P = 0.001；分别地] 基于国家注册表数据库， .ConclusionsThis 学习早显示出早、连续的 statin 治疗 improvs 在在真实世界的临床的实践的一种总线标准以后的 STEMI 病人的结果。

关键词：急性心肌梗死他汀类药物冠状动脉注册表韩国拨号 MACE 低密度脂蛋白

Health risks of pest control and disinfection workers after the COVID-19 outbreak in South Korea

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Journal of Environmental Sciences 2024年第5期139卷 350-363页

作者： Yun-hee Choi Da-An Huh Lita Kim Sang ji lee Kyong Whan Moon Department of Health and Safety Convergence Science Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea BK21 FOUR R&E Center for Learning Health System Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea Institute of Sciences Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea Department of Health and Environmental Science Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea

The exposure patterns of pest control and disinfection workers have changed after the coronavirus disease 2019(COVID-19)outbreak,but the health risks of chemical exposure have not been *** identified these workers’chemical exposure patterns and risks before and after the COVID-19 *** used data conducted between 2018(pre-pandemic)and 2021(post-pandemic)from three-year cross-sectional surveys on pest control and disinfection *** and dermal exposure concentrations were estimated using equations based on a biocidal product risk assessment model from the Korean National Institute of Environmental *** non-carcinogenic and carcinogenic risks of chemicals were calculated using the United States Environmental Protection Agency risk assessment *** found that the annual work frequency(50^(th)percentile)of foggers using disinfectants increased the most among all the work types,from 140 uses/year to 176 uses/year after the COVID-19 ***,all chemicals’non-carcinogenic and carcinogenic risks increased regardless of exposure *** the worst scenario(95^(th)percentile),the margin of exposure for citric acid,benzethonium chloride,benzyl-C12-16-alkyldimethyl chlorides,and sodium chlorite of inhalation exposure,and isopropyl alcohol and benzyl-C12-16-alkyldimethyl chlorides of dermal exposure were acceptable(>100)before the COVID-19outbreak but became unacceptable(10^(-6))before and after the COVID-19 outbreak but comparatively high after the COVID-19 ***,significantly more workers experienced health symptoms after the COVID-19outbreak(p<0.05),with the most common being muscle lethargy(31%),skin/face stinging(28.7%),and breath shortness/neck pain(24.1%).

关键词： Biocide Disinfection Health risk assessment Occupational exposure Pest control

Two-stage dynamic recrystallization and texture evolution in Al-7Mg alloy during hot torsion

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1900-1911页

作者： Kwang Tae Son chang hee Cho Myoung Gyun Kim Ji Woon lee School of Mechanical Industrialand Manufacturing EngineeringOregon State UniversityCorvallis OR 97331USA Department of Materials Science Engineering Northwestern UniversityEvanston IL 60208USA Research Institute of Industrial Science and Technology(RIST) Pohang 37673Rep.of Korea Division of Advanced Materials Engineering Kongju National UniversityCheonan 31080Rep.of Korea Center for Advanced Materials and Parts of Powders Kongju National UniversityCheonan 31080Rep.of Korea

Hot torsion tests were performed on the Al-7Mg alloy at the temperature ranging from 300 to 500℃ and strain rates between 0.05 and 5 s^(-1) to explore the progressive dynamic recrystallization(DRX)and texture *** DRX behavior of the alloy manifested two distinct stages:Stage 1 at strain of≤2 and Stage 2 at strains of≥*** Stage 1,there was a slight increase in the DRXed grain fraction(X_(DRX))with predominance of discontinuous DRX(DDRX),followed by a modest change in X_(DRX) until the transition to Stage *** 2 was marked by an accelerated rate of DRX,culminating in a substantial final X_(DRX) of~*** backscattered diffraction(EBSD)analysis on a sample in Stage 2 revealed that continuous DRX(CDRX)predominantly occurred within the(121)[001]grains,whereas the(111)[110]grains underwent a geometric DRX(GDRX)evolution without a noticeable sub-grain ***,a modified Avrami’s DRX kinetics model was utilized to predict the microstructural refinement in the Al-7Mg alloy during the DRX *** this kinetics model did not accurately capture the DDRX behavior in Stage 1,it effectively simulated the DRX rate in Stage *** texture index was employed to assess the evolution of the texture isotropy during hot-torsion test,demonstrating significant improvement(>75%)in texture randomness before the commencement of Stage *** initial texture evolution is attributed to the rotation of parent grains and the substructure evolution,rather than to an increase in X_(DRX).

关键词： Al-7Mg alloys hot deformation hot torsion tests dynamic recrystazlliation microstructure texture