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Evaluation of Unified Model Microphysics in High-resolution NWP Simulations Using Polarimetric Radar Observations

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Advances in Atmospheric Sciences 2018年第7期35卷 771-784页

作者： Marcus JOHNSON Youngsun JUNG Daniel DAWSON Timothy SUPINIE Ming XUE Jongsook PARK yong-hee lee Center for Analysis and Prediction of Storms (CAPS) University of Oklahoma Norman OK 73072 USA School of Meteorology University of Oklahoma Norman OK 73072 USA Purdue University West Lafayette IN 47907 USA Korea Meteorological Administration Seoul 07062 Korea

The UK Met Office Unified Model（UM） is employed by many weather forecasting agencies around the globe. This model is designed to run across spatial and time scales and known to produce skillful predictions for large-scale weather systems. However, the model has only recently begun running operationally at horizontal grid spacings of ～1.5 km [e.g.,at the UK Met Office and the Korea Meteorological Administration（KMA）]. As its microphysics scheme was originally designed and tuned for large-scale precipitation systems, we investigate the performance of UM microphysics to determine potential inherent biases or weaknesses. Two rainfall cases from the KMA forecasting system are considered in this study： a Changma（quasi-stationary） front, and Typhoon Sanba（2012）. The UM output is compared to polarimetric radar observations in terms of simulated polarimetric radar variables. Results show that the UM generally underpredicts median reflectivity in stratiform rain, producing high reflectivity cores and precipitation gaps between them. This is partially due to the diagnostic rain intercept parameter formulation used in the one-moment microphysics scheme. Model drop size is generally both underand overpredicted compared to observations. UM frozen hydrometeors favor generic ice（crystals and snow） rather than graupel, which is reasonable for Changma and typhoon cases. The model performed best with the typhoon case in terms of simulated precipitation coverage.

关键词： Unified Model microphysics polarimetric radar radar simulator numerical weather prediction

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

Ionizing terahertz waves with 260 MV/cm from scalable optical rectification

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维普期刊数据库

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Light(Science & Applications) 2024年第6期13卷 1075-1087页

作者： Hyeongmun Kim Chul Kang Dogeun Jang Yulan Roh Sang Hwa lee Joong Wook lee Jae hee Sung Seong Ku lee Ki-yong Kim Advanced Photonics Research Institute GISTGwangju61005Korea Department of Physics and Optoelectronics Convergence Research Center Chonnam National UniversityGwangju61186Korea Pohang Accelerator Laboratory POSTECHPohang37673Korea Center for Relativistic Laser Science Institute for Basic ScienceGwangju61005Korea Institute for Research in Electronics and Applied Physics Department of PhysicsUniversity of MarylandCollege ParkMaryland20742USA

Terahertz(THz)waves,known as non-ionizing radiation owing to their low photon energies,can actually ionize atoms and molecules when a sufficiently large number of THz photons are concentrated in time and ***,we demonstrate the generation of ionizing,multicycle,15-THz waves emitted from large-area lithium niobate crystals via phase-matched optical rectification of 150-terawatt laser pulses.A complete characterization of the generated THz waves in energy,pulse duration,and focal spot size shows that the field strength can reach up to 260 megavolts per *** particular,a single-shot THz interferometer is employed to measure the THz pulse duration and spectrum with complementary numerical *** intense THz pulses are irradiated onto various solid targets to demonstrate THz-induced tunneling ionization and plasma *** study also discusses the potential of nonperturbative THz-driven ionization in gases,which will open up new opportunities,including nonlinear and relativistic THz physics in plasma.

关键词： optical interferometer matched

Investigation of acoustic attributes based on preference and perceptional acoustics of Korean traditional halls for optimal design solutions

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维普期刊数据库

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Building Simulation 2024年第5期17卷 723-738页

作者： Beta Bayu Santika Haram lee Jin yong Jeon Department of Architectural Engineering Hanyang UniversitySeoul 04763R.O.Korea

Immersed in the rich tapestry of traditional culture,Gugak,the traditional Korean music stands as a captivating embodiment of artistic *** study embarked on a comprehensive evaluation of a Gugak hall,employing acoustic measurements,computer simulations,and subjective perception *** evaluation focused on the reverberance,clarity,spatial impression,and preference,unravelling the secrets that shape the immersive Gugak *** intricate computer simulations and auralization,the experience of Gugak performances was meticulously brought to life,allowing exploration under diverse conditions by adjusting stage volume ratios from -20% to+20% and modifying the interior materials,including the walls,ceiling,and lateral *** Gugak halls exhibited relatively low values of reverberation time(RT),early decay time(EDT),and binaural quality index(BQI)the dominant factor influencing the acoustic environment was the effect of sound strength(G).Musical clarity(C80)value did not show an inverse proportionality to the reverberation ***,genre differences between traditional Korean and Western classical music did not significantly affect listeners’perception and satisfaction with regards to reverberance,clarity,and spatial *** a result,Gugak halls can adhere to the same acoustic design criteria as Western orchestra halls,since this study found that people perceived them the same *** this study,sound strength was found to be strongly correlated with perception *** was possible to enhance listeners’perception and preference regarding the acoustic environment through material and structural changes to the sidewalls and *** changes improved the reinforcement of low frequencies and simultaneously enhanced the relative effect of side ***,enhancing the reflection and spatial characteristics of the materials effectively improved listener *** on these findings,an optimal des

关键词： Korean traditional hall acoustical parameters perceptual evaluation acoustic preference stage volume ratio

Optical Bistability in 2D Photonic Crystal Slab Resonators

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维普期刊数据库

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Optical Bistability in 2D Photonic Crystal Slab Resonators

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

国际纳光电子学研讨会

作者： Myung-Ki Kim In-Kag Hwang yong-hee lee Department of Physics Korea Advanced Institute of Science and Technology（KAIST） Daejeon 305-701Korea Department of physics Chonnam National University Korea Advanced Institute of Science and Technology（KAIST） Korea

＜正＞We report the low-power optical bistability under the continuous wave pumping conditions in photonic crystal linear resonators containing the InGaAsP quantum well active medium. The threshold bistable power is m...

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来源： cnki会议评论

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cnki会议

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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

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

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

Guardian of the rice:Unveiling OsSSP1 for broad-spectrum disease resistance

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Molecular Plant 2024年第7期17卷 996-998页

作者： You-Jin Lim yong-Hwan lee Research Institute of Agriculture and Life Sciences Seoul National UniversitySeoul08826Republic of Korea Department of Agricultural Biotechnology Seoul National UniversitySeoul 08826Republic of Korea interdisciplinary Program in Agricultural Genomics Center for Fungal Genetic ResourcesPlant Immunity Research Centerand Center for Plant Microbiome ResearchSeoul National UniversitySeoul 08826Republic of Korea

Plants are continuously exposed to numerous biotic stresses throughout their *** arms race-driven coevolution with pathogens,plants have developed sophisticated immune systems,including pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)and effector-triggered immunity(ETI).PTI is initiated by the binding of danger signals to extracellular membrane-localized receptors calledpattern recognition receptors(PRRs).PTI triggers responses,including reactive oxygen species(ROS)bursts and the expression of defenseassociated ***,pathogens adapted to PTl secrete virulence proteins,effectors,to aid colonization,and ETl is then triggered by the recognition of these effectors by resistance proteins with a nucleotide-binding domain leucinerich repeat receptor(NLR).To circumvent this immune response,pathogens secrete various effectors into the host intracellular region and induce effector-triggered susceptibility(Zhou and Zhang.,2020).Currently,research on plant immunity has been primarily focused on plasma membrane and cytoplasmlocalized proteins,including oligomeric NLRs,resistosomes,and the secretion mechanisms of cytoplasmic effectors.

关键词： immunity resistance Guard