检索结果-南通市图书馆

Random pinhole attenuator for high-power laser beams

在线全文

学校读者我要写书评

暂无评论

High Power Laser Science and Engineering 2024年第3期12卷 116-121页

作者： Seong Cheol Park Hyeok Yun jin woo Yoon Seong Ku Lee Jae Hee Sung Il woo Choi Chang Hee Nam Kyung Taec kim Department of Physics and Photon Science Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea Center for Relativistic Laser Science Institute for Basic ScienceGwangjuRepublic of Korea Advanced Photonics Research Institute Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea

The intensity attenuation of a high-power laser is a frequent task in the measurements of optical *** intensity can be attenuated by inserting an optical element,such as a partial reflector,polarizer or absorption *** devices are,however,not always easily applicable,especially in the case of ultra-high-power lasers,because they can alter the characteristics of a laser beam or become easily *** this study,we demonstrated that the intensity of a laser beam could be effectively attenuated using a random pinhole attenuator(RPA),a device with randomly distributed pinholes,without changing the beam *** this device,a multi-PW laser beam was successfully attenuated and the focused beam profile was measured without any alterations of its *** addition,it was confirmed that the temporal profile of a laser pulse,including the spectral phase,was ***,the RPA possesses significant potential for a wide range of applications.

关键词： high-power laser intensity attenuation laser diagnostics

Tetramic acid-motif natural products from a marine fungus Tolypocladium cylindrosporum FB06 and their anti-Parkinson activities

在线全文

学校读者我要写书评

暂无评论

Marine Life Science & Technology 2024年第1期6卷 84-92页

作者： Yuna Jung Chaesun Kwon Taeyeon kim jin woo Lee Min-Kyoo Shin Sang Hee Shim Natural Products Research Institute College of PharmacySeoul National UniversitySeoul 08826Republic of Korea College of Pharmacy and Research Institute of Pharmaceutical Sciences Seoul National UniversitySeoul 08826Republic of Korea College of Pharmacy Duksung Women’s UniversitySeoul 01369Republic of Korea

Tetramic acid-containing natural products are attracting significantly increasing attention from biologists and chemists due to their intriguing structures and biological *** the present study,two new tetramic acid alkaloids tolypyridone I(1)and tolypyridone J(2),together with five known ones(3–7),were isolated from cultures of a marine fungus Tolypocladium cylindrosporum FB06 isolate obtained from a marine sediment in Beaufort sea of North *** structures were elucidated using 1D,2D NMR,and *** configurations were established on the basis of 1H coupling constants,ROESY correlations and DP4 *** 2 was isolated as mixtures of rotational isomers with C-3 to C-7 axis between 4-hydroxy-2-pyridone and 1-ethyl-3,5-dimethylcyclohexane,hindering *** our unbiased screening to discover neuroprotective compounds in an in vitro Parkinson’s disease(PD)model,SH-SY5Y dopaminergic cells were treated with isolated compounds followed by treatment with 1-methyl-4-phenylpyridinium(MPP^(+)),a parkinsonian *** tested compounds,F-14329(7)significantly protected cells from MPP^(+)-induced ***^(+)-mediated cell death is known to be related to the regulation of Bcl-2 family proteins,specifically the down-regulation of anti-apoptotic Bcl-2 and the up-regulation of pro-apoptotic Bax *** with 2 mmol/L of MPP^(+)for 24 h significantly reduced Bcl-2 levels compared to control treated with ***,treatment with F-14329(7)attenuated such *** study demonstrates that tetramic acid-motif compounds could be potential lead compounds for treating PD.

关键词： Tolypocladium cylindrosporum Tetramic acid Tolypyridone Parkinson’s disease

Two distinct subpopulations of marginal zone B cells exhibit differential antibody-producing capacities and radioresistance

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2024年第4期21卷 393-408页

作者： Sujin Lee Yeunjung Ko Hyun woo Lee Won Joon Oh Hun Gi Hong Dinuka Ariyaratne Se jin Im Tae jin kim Department of Immunology Graduate School of Basic Medical ScienceSungkyunkwan University School of MedicineSuwon16419Republic of Korea Department of Immunology and Molecular Medicine Faculty of Medical SciencesUniversity of Sri JayewardenepuraNugegodaSri Lanka Present address:Immunology and Microbiology Graduate Program Baylor College of MedicineHoustonTX77030USA

Marginal zone(MZ)B cells,which are splenic innate-like B cells that rapidly secrete antibodies(Abs)against blood-borne pathogens,are composed of heterogeneous ***,we showed that MZ B cells can be divided into two distinct subpopulations according to their CD80 expression ***80^(high)MZ B cells exhibited greater Ab-producing,proliferative,and IL-10-secreting capacities than did CD80^(low)MZ B ***,CD80^(high)MZ B cells survived 2-Gy whole-body irradiation,whereas CD80^(low)MZ B cells were depleted by irradiation and then repleted with one month after *** of CD80^(low)MZ B cells led to accelerated development of type II collagen(CII)-induced arthritis upon immunization with bovine ***80^(high)MZ B cells exhibited higher expression of genes involved in proliferation,plasma cell differentiation,and the antioxidant ***80^(high)MZ B cells expressed more autoreactive B cell receptors(BCRs)that recognized double-stranded DNA or CII,expressed more immunoglobulin heavy chain sequences with shorter complementarity-determining region 3 sequences,and included more clonotypes with no N-nucleotides or with B-1a BCR sequences than CD80^(low)MZ B *** transfer experiments showed that CD21^(+)CD23^(+)transitional 2 MZ precursors preferentially generated CD80^(low)MZ B cells and that a proportion of CD80^(low)MZ B cells were converted into CD80^(high)MZ B cells;in contrast,CD80^(high)MZ B cells stably remained CD80^(high)MZ B *** summary,MZ B cells can be divided into two subpopulations according to their CD80 expression levels,Ab-producing capacity,radioresistance,and autoreactivity,and these findings may suggest a hierarchical composition of MZ B cells with differential stability and BCR specificity.

关键词： Marginal Zone B Cell CD80 Autoreactivity Radioresistance

Development and application of a multi-step porcine in vitro system to evaluate feedstuffs and feed additives for their efficacy in nutrient digestion, digesta characteristics, and intestinal immune responses

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第2期17卷 265-282页

作者： Hee Yeon kim Jun-Ok Moon Sung woo kim Application Center CJ Blossom Park Department of Animal Science North Carolina State University

In vitro model provides alternatives to the use of live animals in research. In pig nutrition, there has been a tremendous increase in in vivo research over the decades. Proper utilization of in vitro models could provide a screening tool to reduce the needs of in vivo studies, research duration, cost, and the use of animals and feeds. This study aimed to develop a multi-step porcine in vitro system to simulate nutrient digestion and intestinal epithelial immune responses affected by feedstuffs and feed additives. Seven feedstuffs(corn, corn distillers dried grains with solubles [corn DDGS], barley, wheat, soybean meal, soy protein concentrates, and Corynebacterium glutamicum cell mass [CGCM]), feed enzymes(xylanase and phytase), and supplemental amino acids(arginine, methionine, and tryptophan), were used in this in vitro evaluation for their efficacy on digestibility, digesta characteristics, and intestinal health compared with the results from previously published in vivo studies. All in vitro evaluations were triplicated. Data were analyzed using Mixed procedure of SAS9.4. Evaluations included(1) nutrient digestibility of feedstuffs,(2) the effects of feed enzymes, xylanase and phytase, on digestibility of feedstuffs and specific substrates, and(3) the effects of amino acids, arginine, tryptophan, and methionine, on anti-inflammatory, anti-oxidative, and anti-heat stress statuses showing their effects(P < 0.05) on the measured items. Differences in dry matter and crude protein digestibility among the feedstuffs as well as effects of xylanase and phytase were detected(P < 0.05), including xylo-oligosaccharide profiles and phosphorus release from phytate. Supplementation of arginine, tryptophan, and methionine modulated(P < 0.05) cellular inflammatory and oxidative stress responses. The use of this in vitro model allowed the use of 3 experimental replications providing sufficient statistical power at P < 0.05. This indicates in vitro models can have increased prec

关键词： Digestion Feed additive Feedstuff In vitro Intestine Pig

Boosted Lithium-Ion Transport Kinetics in n-Type Siloxene Anodes Enabled by Selective Nucleophilic Substitution of Phosphorus

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第10期16卷 618-637页

作者： Se In kim woong-Ju kim jin Gu Kang Dong-Wan kim School of Civil Environmental and Architectural EngineeringKorea University02841 SeoulSouth Korea Nanophotonics Research Center Korea Institute of Science and Technology02792 SeoulSouth Korea

Doped two-dimensional(2D)materials hold significant promise for advancing many technologies,such as microelectronics,optoelectronics,and energy ***,n-type 2D oxidized Si nanosheets,namely n-type siloxene(n-SX),are employed as Li-ion battery *** thermal evaporation of sodium hypophosphite at 275℃,P atoms are effectively incorporated into siloxene(SX)without compromising its 2D layered morphology and unique Kautsky-type crystal ***,selective nucleophilic substitution occurs,with only Si atoms being replaced by P atoms in the O_(3)≡Si-H *** resulting n-SX possesses two delocalized electrons arising from the presence of two electron donor types:(i)P atoms residing in Si sites and(ii)H *** doping concentrations are varied by controlling the amount of precursors or their mean free *** at 2000 mA g^(-1),the n-SX electrode with the optimized doping concentration(6.7×10^(19) atoms cm^(-3))delivers a capacity of 594 mAh g^(-1) with a 73%capacity retention after 500 *** improvements originate from the enhanced kinetics of charge transport processes,including electronic conduction,charge transfer,and solid-state *** approach proposed herein offers an unprecedented route for engineering SX anodes to boost Li-ion storage.

关键词： Li-ion battery Two-dimensional N-type siloxene Doping mechanism Kinetics

Real-time flow-based video abstraction using OpenCL

在线全文

学校读者我要写书评

暂无评论

Journal of Measurement Science and Instrumentation 2012年第1期3卷 46-50页

作者： Yong-jin PARK jin-woo kim jin-hong PARK Tack-don HAN Dept.of Computer Science Yonsei University

A non-photorealistic rendering technique is a method to show various effects different from those of realistic image *** the various techniques,flow-based image abstraction displays the shape and color features well and performs a stylistic visual *** real-time rendering is impossible when CPU is used because it applies various filtering and iteration *** this paper,we present real-time processing methods of video abstraction using open open computing language(OpenCL),technique of general-purpose computing on graphics processing units(GPGPU).Through the acceleration of general-purpose computing(GPU),16 frame-per-second(FPS)or greater is shown to process video abstraction.

关键词： non-photorealistic rendering video abstraction general-purpose computing on graphics processing units(GPGPU) open computing language(OpenCL)

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

在线全文

学校读者我要写书评

暂无评论

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

Boosting the catalytic activity toward oxygen reduction via a heterostructure of porous iron oxide-decorated 2D NiO/NG nanosheets

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第6期93卷 669-681,I0016页

作者： Kakali Maiti Matthew T.Curnan Hyung Jun kim Kyeounghak kim Jeong woo Han Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)PohangGyeongbuk 37673Republic of Korea Department of Materials Science and Engineering Research Institute of Advanced MaterialsSeoul National UniversitySeoul 08826Republic of Korea Department of Chemical Engineering Clean-Energy Research InstituteHanyang UniversitySeoul 04763Republic of Korea CSIR-Institute of Minerals and Materials Technology RRL CampusAcharya ViharBhubaneswarOdisha 751013India

As a noble metal substitute,two-dimensional(2D)hierarchical nano-frame structures have attracted great interest as candidate catalysts due to their remarkable advantages-high intrinsic activity,high electron mobility,and straightforward surface ***,they may replace Pt-based catalysts in oxygen reduction reaction(ORR)***,a simple method is developed to design hierarchical nano-frame structures assembled via 2D NiO and N-doped graphene(NG)*** procedure can yield nanostructures that satisfy the criteria correlated with improved electrocatalytic performance,such as large surface area,numerous undercoordinated atoms,and high defect ***,porous NG nanosheet architectures,featuring NiO nanosheets densely coordinated with accessible holey Fe_(2)O_(3) moieties,can enhance mesoporosity and balance *** improvements can facilitate charge transport and expose formerly inaccessible reaction sites,maximizing active site density *** functional theory(DFT)calculations reveal favored O_(2) adsorption and dissociation on Fe_(2)O_(3) hybrid structures when supported by 2D NiO and NG nanomaterials,given 2D materials donated charge to Fe_(2)O_(3) active *** systematic studies reveal that synergistic contributions are responsible for enriching the catalytic activity of Fe_(2)O_(3)@NiO/NG in alkaline media-encompassing internal voids and pores,unique hierarchical support structures,and concentrated N-dopant and bimetallic atomic ***,this work expands the toolbox for designing and synthesizing highly efficient 2D/2D shelled functional nanomaterials with transition metals,endeavoring to benefit energy conversion and related ORR applications.

关键词： N-doped graphene Holey Fe_(2)O_(3)nanocrystals NiO nanosheets High catalytic performance ORR

Surface-modified Ag@Ru-P25 for photocatalytic CO_(2) conversion with high selectivity over CH_(4) formation at the solid–gas interface

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第1期6卷 182-196页

作者： Chaitanya B.Hiragond Sohag Biswas Niket SPowar Junho Lee Eunhee Gong Hwapyong kim Hong Soo kim jin-woo Jung Chang-Hee Cho Bryan M.Wong Su-Il In Department of Energy Science&Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)DaeguRepublic of Korea Department of Chemical&Environmental Engineering Materials Science&Engineering ProgramDepartment of ChemistryDepartment of Physics&AstronomyUniversity of California-RiversideRiversideCaliforniaUSA Department of Physics and Chemistry Daegu Gyeongbuk Institute of Science and Technology(DGIST)DaeguRepublic of Korea NiceScience Corporation DaeguRepublic of Korea

Systematic optimization of the photocatalyst and investigation of the role of each component is important to maximizing catalytic activity and comprehending the photocatalytic conversion of CO_(2) reduction to solar fuels.A surface-modified Ag@Ru-P25 photocatalyst with H_(2)O_(2) treatment was designed in this study to convert CO_(2) and H_(2)O vapor into highly selective *** doping followed by Ag nanoparticles(NPs)cocatalyst deposition on P25(TiO_(2))enhances visible light absorption and charge separation,whereas H_(2)O_(2) treatment modifies the surface of the photocatalyst with hydroxyl(–OH)groups and promotes CO_(2) ***-resonance transmission electron microscopy,X-ray photoelectron spectroscopy,X-ray absorption near-edge structure,and extended X-ray absorption fine structure techniques were used to analyze the surface and chemical composition of the photocatalyst,while thermogravimetric analysis,CO_(2) adsorption isotherm,and temperature programmed desorption study were performed to examine the significance of H_(2)O_(2) treatment in increasing CO_(2) reduction *** optimized Ag1.0@Ru1.0-P25 photocatalyst performed excellent CO_(2) reduction activity into CO,CH4,and C2H6 with a~95%selectivity of CH4,where the activity was~135 times higher than that of pristine TiO_(2)(P25).For the first time,this work explored the effect of H_(2)O_(2) treatment on the photocatalyst that dramatically increases CO_(2) reduction activity.

关键词： gas-phase CO_(2) reduction H_(2)O_(2) treatment plasmonic nanoparticles solar fuel photocatalyst surface modification