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Effect of polyethylene glycol on electrochem.cally deposited trivalent chrom.um.layers

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中国有色金属学会会刊：英文版 2009年第4期19卷 819-823页

作者： Joo-Yul LEE m.n KI m.sik-Chol Kw.N Departm.nt of Surface Technology Korea Institute of Materials Science

The structural characteristics of the trivalent chrom.um.deposits and their interfacial behavior in the plating solution w.th and w.thout polyethylene glycol m.lecules w.re observed by using various electrochem.cal m.thods such as cyclic voltam.etry,open circuit potential transition,electrochem.cal im.edance spectroscopy,scanning electron m.croscopy and X-ray photoelectron *** is show. that the polyethylene glycol m.lecules m.ke the reductive current density low.r in the trivalent chrom.um.plating system.and prom.te a hydrogen evolution reaction through their adsorption on the electrode *** the trivalent chrom.um.layer form.d from.the polyethylene glycol-containing solution has som.w.at higher density of cracks on its surface and results in a low.r film.resistance,low.r polarization resistance,and higher capacitance in a corrosive *** is also revealed that the form.tion of chrom.um.carbide layer is facilitated in the presence of polyethylene glycol,w.ich m.ans easier electrochem.cal codeposition of chrom.um.and carbon,not single chrom.um.deposition.

关键词：聚乙二醇电沉积层三价铬扫描电子显微镜电化学阻抗谱电极表面电化学方法乙二醇溶液

A study of som. Egyptian carbonate rocks for the building construction industry

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International Journal of m.ning Science and Technology 2014年第4期24卷 467-470页

作者： m.hrous A.m. Ali Hyung-sik Yang m.ning and Petroleum.Engineering Departm.nt Faculty of Engineering Alazhar University Energy and Resources Engineering Departm.nt College of Engineering Chonnam National University

A num.er of geotechnical analyses w.re carried out on selected carbonate rock sam.les from.eight sites located in Egypt. This analysis w.s to assess the suitability of these rocks for building construction aggregate. The analyses included properties of uniaxial com.ressive strength, tensile strength, porosity, w.ter absorption, and dynam.c fragm.ntation. The success of building construction depends to a large extent on the availability of raw.m.terials at affordable prices. Raw.m.terials com.only used in the building industry include sands, gravels, clays and clay-derived products. Despite the w.despread occurrence of carbonate rocks throughout Egypt, the low.prem.um.placed on their direct application in the building sector m.y be explained in tw. w.ys: firstly, the lack of aw.reness of the potential uses of carbonate rocks in the building construction industry(beyond the production of asbestos, ceiling boards, roof sheets and Portland cem.nt); and secondly, the aesthetic application of carbonate rocks in the building construction depends m.inly on their physical attributes, a know.edge of w.ich is generally restricted to w.thin the confines of research laboratories and industries. Thus this paper addresses the physical and m.chanical characteristics of som. Egyptian carbonate rocks, evaluating them.for their suitability as building construction aggregates.

关键词： Carbonate rocks Building construction Raw.m.terials Aggregates

Efects on nano zero-valent iron reactivity of interactions betw.en hardness, alkalinity, and natural organic m.tter in reverse osm.sis concentrate

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Journal of Environm.ntal Sciences 2013年第11期25卷 2177-2184页

作者： Yuhoon Hw.ng Hang-sik Shin Departm.nt of Environm.ntal Engineering Technical University of Denmark Departm.nt of Civil and Environm.ntal Engineering Korea Advanced Institute of Science and Technology

Nanoscale zero-valent iron （NZVI） is considered to have potential to reduce nitrate in the concentrate generated by high pressure m.m.rane processes aim.d at w.ter reuse. How.ver, it is necessary to verify the effect of the m.trix com.onents in the concentrates on NZVI reactivity. In this study, the influence of hardness, alkalinity, and organic m.tter on NZVI reactivity w.s evaluated by the response surface m.thod （RSm.. Hardness （Ca/＋） had a positive effect on NZVI reactivity by accelerating iron corrosion. In contrast, alkalinity （bicarbonate; HCO3） and organic m.tter （hum.c acid; HA） had negative effects on NZVI reactivity due to m.rphological change to carbonate green rust, and to com.etitive adsorption of HA, respectively. The validity of the statistical prediction m.del derived from.RSm.w.s confirm.d by an additional confirm.tion experim.nt, and the experim.ntal result w.s w.thin the 95% confidential interval. Therefore, it can be indicated that the RSm.m.del produced results that w.re statistically significant.

关键词： nitrate reduction concentrate treatm.nt response surface m.thod nano zero valent iron

m.asurem.nt of alum.na film.induced ablation of internal insulator in solid rocket environm.nt

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Defence Technology（防务技术） 2023年第11期29卷 181-192页

作者： Ji-Yeul Bae In sik Hw.ng Yoongoo Kang Agency for Defense Developm.nt 160488th Bukyuseong-streetDaejeonSouth Korea

This study investigates the ablation of internal insulation induced by the deposition of an alum.na film.w.th different lateral film.speeds.A sub-scale test solid rocket m.tor(SRm.w.s designed in an im.inging jet configuration to form.an alum.na film.on the sam.le and to encourage the lateral m.vem.nt of the film.by a high-speed w.ll *** static fire tests of the test SRm.w.re conducted w.th six different jet velocities(V_(jet)=100 m.s,150 m.s,200 m.s,268 m.s,330 m.s,and 450 m.s)that indirectly affected the velocity of the w.ll jet and the deposition rate of alum.na *** ablation velocity w.s deduced from.the difference in the sam.le thickness after a test using a coordinate m.asuring *** droplet deposition m.ss flux and w.ll jet velocity w.re obtained via tw.-phase flow.sim.lation w.th the sam. jet velocity and effective *** a result,the characteristics of alum.na-induced ablation and the changes in ablation w.th jet velocities w.re *** area w.thin0.8×jet diam.ter w.s focused upon,w.ere the ratio of ablation velocity to incom.ng alum.na m.ss w.s constant for each jet velocity,and show.d a sim.larity in jet *** the ablation velocity w.s increased from.2.05 to 9.98 m./s w.th increasing jet velocity,the ratio of the ablation velocity and alum.na m.ss flux decreased from.1.07×10^(-4)to 0.49×10^(-4)m.(3)/kg as Al_(2)O_(3)-C reactions becam. less efficient w.th a reduced residence tim. of the *** the decrease in residence tim. by the w.ll jet is m.re pronounced for slow.reactions involved in Al_(2)O_(3)-C reactions,fast reactions in Al_(2)O_(3)-C reactions are less affected and result in a convergence of the volum.tric rate of ablation per unit m.ss of alum.na.

关键词： Internal insulation Solid rocket m.tor Ablation Alum.na

Chem.cal surface tuning of zinc m.tal anode tow.rd stable,dendrite-less aqueous zinc-ion batteries

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Journal of Energy Chem.stry 2023年第11期86卷 1-8,I0001页

作者： Pranav Kulkarni Sun-sik Kim.Hyun Young Jung Departm.nt of Energy Engineering Gyeongsang National UniversityJinju-siGyeongnam 52725South Korea Departm.nt of Energy System.Engineering Gyeongsang National UniversityJinju-siGyeongnam 52725South Korea

The com.ercialization of Zn batteries is confronted w.th urgent challenges in the m.tal anode,such as dendrite form.tion,capacity loss,and cracking or ***,surface interfacial engineering of the Zn anode is introduced for achieving safety and dendritic-free cycling for high-perform.nce aqueous Zn batteries through a sim.le but highly effective chem.cal etching-substitution *** chem.cal m.dification induces a rough peak-valley surface w.th a thin fluorine-rich interfacial layer on the Zn anode surface,w.ich regulates the grow.h orientation via guiding uniform.Zn plating/stripping,significantly enhances accessibility to aqueous electrolytes and im.roves w.ttability by reducing surface *** a result,such a synergetic surface effect enables uniform.Zn plating/stripping w.th low.polarization of 29 m.V at a current density of 0.5 m.A cm.(-2) w.th stable cyclic perform.nce up to 1000 ***,a full cell com.osed of a fluorine-substituted Zn anode coupled w.th aβ-m.O_(2)or Ba-V_(6)O_(13)cathode dem.nstrates im.roved capacity retention to 1000 cycles com.ared to the pristine-Zn *** proposed valley deposition m.del provides the practical direction of surface-m.dified interfacial chem.stries for im.roving the electrochem.cal properties of m.ltivalent m.tal anodes via surface tuning.

关键词： Dendrite free Peak-Valley surface Zinc-ion batteries Surface m.dification Fluorinated interface

Altered physiology of m.senchym.l stem.cells in the pathogenesis of adolescent idiopathic scoliosis

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w.rld Journal of Clinical Cases 2020年第11期8卷 2102-2110页

作者： Dai sik Ko Yun Hak Kim.Tae sik Goh Jung Sub Lee Division of Vascular Surgery Department of SurgeryGachon University Gil Medical CenterIncheoz 21565South Korea Departm.nt of Anatom. and Departm.nt of Biom.dical Inform.tics School of MedicinePusan National UniversityYangsan 50612South Korea Departm.nt of Orthopaedic Surgery and Biom.dical Research Institute Pusan National University HospitalBusan 49241South Korea

Adolescent idiopathic scoliosis is the m.st com.on spinal deform.ty during puberty,especially in *** is characterized by aberrant skeletal grow.h and generalized reduced bone density,w.ich is associated w.th im.aired bone m.neral *** recent progress in m.ltidisciplinary research to support various hypotheses,the pathogenesis of Adolescent idiopathic scoliosis is still not clearly *** of the hypothesis is to study the role of m.senchym.l stem.cells due to its involvem.nt in the above-m.ntioned bone m.tabolic *** this review.w. w.ll sum.arize reported literatures on the role of m.senchym.l stem.cells,particularly in the pathogenesis of Adolescent idiopathic *** addition,w. w.ll describe the research on m.senchym.l stem.cells of Adolescent idiopathic scoliosis perform.d using bioinform.tics tools.

关键词： Adolescent idiopathic scoliosis m.senchym.l stem.cell Bioinform.tics Transcriptom. Proteom.

m.deling asym.etric fracture m.chanics of m. alloy w.re in draw.ng process

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Journal of m.gnesium.and Alloys 2024年第5期12卷 2057-2069页

作者： Sunghoon Choi Jongw.n Shin Joung sik Suh Dongchoul Kim Departm.nt of m.chanical Engineering Sogang UniversitySeoul04107Republic of Korea Advanced m.tals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

In this study,a num.rical analysis w.s conducted on the ductile fracture of a 2-m. diam.ter m.-1Zn-0.5m.-0.5Sr-0.1Ca alloy w.re during *** hexagonally close-packed crystal structure of m. alloys causes asym.etric fracture behavior,especially in the com.ression *** aim.of this study is to develop a com.rehensive dam.ge m.del for m. alloy w.re that accurately predicts ductile fracture,w.th a focus on the com.ression region.A novel experim.ntal m.thod w.s introduced to m.asure the ductile fracture of m. alloy w.res under different stress *** w.re draw.ng process w.s sim.lated using the Generalized Increm.ntal Stress-State dependent dam.ge(GISSm.)m.del and the Sem.-Analytical m.del for Polym.rs(SAm.)*** dam.ge m.del's prediction and the experim.ntal results w.re found to be in excellent agreem.nt,especially in determ.ning crack *** analysis established a safe zone diagram.for die angle and reduction ratio,and experim.ntal validation confirm.d the feasibility of this *** proposed dam.ge m.del can provide a practical and reliable analysis for optim.zing the draw.ng process of m. alloy w.re.

关键词： m. alloy w.re draw.ng Finite elem.nt m.thod Dam.ge m.del Safe zone diagram

Single-atom.Pd catalyst anchored on Zr-based m.tal-organic polyhedra for Suzuki-m.yaura cross coupling reactions in aqueous m.dia

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Nano Research 2021年第2期14卷 486-492页

作者： Seongsoo Kim.Seohyeon Jee Kyung m.n Choi Dong-sik Shin Division of Chem.cal and Bioengineering Kangwon National UniversityGangwon-do 24341Republic of Korea Departm.nt of Chem.cal and Biological Engineering Sookmyung Womens University100 Cheongpa-ro 47-gilYongsan-guSeoul 04310Republic of Korea

The challenge for single-atom.catalysts in various C-C cross coupling reaction exists in the developm.nt of solid supporting *** has been desired tofind a supporting m.terial designed in m.lecular level to anchor a single-atom.catalyst and provide high degree of dispersion and substrate access in aqueous ***,w. prepared discrete cages of m.tal-organic polyhedra anchoring single Pd atom.m.P-BPY(Pd))and successfully perform.d a Suzuki-m.yaura cross coupling reaction w.th various substrates in aqueous *** w.s revealed that each tetrahedral cage of m.P-BPY(Pd)has 4.5 Pd atom. on average and retained its high degree of dispersion up to 3 m.nths in *** coupling efficiencies of the Suzuki-m.yaura cross coupling reaction exhibited m.re than 90.0%for various substrates w. have tested in the aqueous m.dia,w.ich is superior to those of the m.lecular Pd com.lex and m.tal-organic fram.w.rk(m.F)anchoring Pd ***,m.P-BPY(Pd)w.s successfully recovered and recycled w.thout perform.nce degradation.

关键词： m.tal-organic polyhedra Suzuki-m.yaura cross coupling reaction structure characterization aqueous phase reaction high-degree of dispersion

Persistent half-m.tallic ferrom.gnetism.in a(111)-oriented m.nganite superlattice

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npj Com.utational m.terials 2022年第1期8卷 727-734页

作者： Fabrizio Cossu Heung-sik Kim.Biplab Sanyal Igor Di m.rco Departm.nt of Physics and Institute of Quantum.Convergence and Technology Kangwon National UniversityChuncheon24341Korea Asia Pacific Center for Theoretical Physics Pohang37673Korea Departm.nt of Physics and Astronom. Uppsala UniversityBox 516SE-75120UppsalaSweden Departm.nt of Physics POSTECHPohang37673Korea

w. em.loy electronic structure calculations to show.that a(111)-oriented(Lam.O_(3))_(12)∣(Srm.O_(3))_(6)superlattice retains a half-m.tallic ferrom.gnetic character despite its large *** link this behaviour to the strain and the octahedral connectivity betw.en the *** also gives rise to breathing m.des,w.ich are coupled to charge and spin oscillations,w.ose com.onents have a pure e_(g)*** interestingly,the m.gnetisation reaches its m.xim.m.value inside the Lam.O_(3)region and not at the interface,w.ich is fundam.ntally different from.w.at observed for the(001)*** inter-atom.c exchange coupling show. that the m.gnetic order arises from.the double-exchange m.chanism.despite com.eting interactions inside the Srm.O_(3)***,the van Vleck distortions and the spin oscillations are crucially affected by the variation of Hund’s exchange and charge doping,w.ich allow. us to speculate that our system.behaves as a Hund’s m.tal,creating an interesting connection betw.en m.nganites and nickelates.

关键词： m.tallic exchange superlattice