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Effect of drawing speed on microstructure distribution and drawability in twinning-induced plasticity steel during wire drawing

Ⅸ International Congress on medical and Applied malacology

作者： P.R.Chung C.T.Soh Y.k.Park m.k.hwang Dept.of Parasitology Inha University College of medicine Inchon 400-712Korea. Dept.of Parasitology Wonkwang University College of medicine lksan 570-749 Korea. Dept.of Parasitology Inha University College of medicine Inchon 400-712Korea. Dept.of Parasitology Inha University College of medicine Inchon 400-712Korea.

＜正＞Three species of the pulmonate snails of the family Planorbidae have been reported from korea;Gyraulus convexiusculus,Hippeutis（Helicorbis）cantori and Segmentina （Polypylis）*** these 3 species,*** and *** ar...

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Journal of Iron and Steel Research International 2020年第5期27卷 577-587页

作者： Joong-ki hwang School of mechanical Engineering Tongmyong UniversityBusan 48520Republic of Korea

The effect of drawing speed on temperature rise and microstructure distribution in twinning-induced plasticity(TWIP)steel during wire drawing has been investigated to improve drawability for wire rod *** wire drawing process is performed at room temperature,heat is generated due to the plastic deformation and friction at the wire-die *** steel wires subjected to the low drawing speed(LD)of 0.5 m/min and the high drawing speed(HD)of 5.0 m/min were analyzed using the numerical simulation and electron backscatter diffraction ***,the specimens subjected to the HD had a higher drawability by about 18%compared to the LD,which is totally different from the general behavior of plain carbon pearlitic *** LD wire had uniform temperature distribution along the radial direction during wire *** contrast,the HD wire had a temperature gradient along the radial direction due to the higher frictional effect at surface:the minimum temperature of 58℃ at center area and the maximum temperature of 143 C at surface *** higher stacking fault energy of HD wire at the surface area due to the high temperature rise retarded twinning rate,resulting in the prevention of fast exhaustion in ductility in comparison with the LD wires since the earlier depletion of twins at surface area is known as the main reason for the fracture of TWIP steel during wire ***,HD process delayed the fracture strain of wire and increased the uniformity of microstructure and mechanical properties along the radial direction.

关键词： Twinning-induced plasticity steel Wire drawing Deformation twin Drawing speed Temperature rise

L^(p) Boundedness of Fourier Integral Operators in the Class S_(0,0)

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Acta mathematica Sinica,English Series 2022年第9期38卷 1551-1596页

作者： Ing-Lung hwang Department of mathematics "National Chung Cheng University of Taiwan"Chiayi County 621003China

We first prove the L~2-boundedness of a Fourier integral operator where it’s symbol a ∈S_(1/2,1/2)~0(R~n× R~n) and the phase function S is non-degenerate,satisfies certain conditions and may not be positively homogeneous in ξ-*** we use the above property,Paley’s inequality,covering lemma of Calderon and Zygmund etc.,and obtain the L~p-boundedness of Fourier integral operators if(1) the symbol a ∈ Λ_(k)^(m_(0)) and Supp a = E×R~n,with E a compact set of R~n(m_(0) =-|1/p-1/2|n,1k>n/2;2k>n/p),(2) the symbol a ∈ Λ_(0,k,k’)^(m_(0))(m_(0) =-|1/p-1/2|n,1k>n/2,k’>n/p;2k>n/p,k’>n/2) with the phase function S(x,ξ) = xξ + h(x,ξ),x,ξ ∈ R~n non-degenerate,satisfying certain conditions and ?ξ h ∈ S_(1,0)~0(R~n× R~n),or(3) the symbol a ∈ Λ_(0,k,k’)^(m_(0)),the requirements for m_(0),k,k’ are the same as in(2),and ?_(ξ)h is not in S_(1,0)~0(R~n× R~n) but the phase function S is non-degenerate,satisfies certain conditions and is positively homogeneous in ξ-variables.

关键词： Fourier integral operator L^(p)-boundedness

Efects on nano zero-valent iron reactivity of interactions between hardness, alkalinity, and natural organic matter in reverse osmosis concentrate

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Journal of Environmental Sciences 2013年第11期25卷 2177-2184页

作者： Yuhoon hwang Hang-Sik Shin Department of Environmental Engineering Technical University of Denmark Department of Civil and Environmental 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 membrane processes aimed at water reuse. However, it is necessary to verify the effect of the matrix components in the concentrates on NZVI reactivity. In this study, the influence of hardness, alkalinity, and organic matter on NZVI reactivity was evaluated by the response surface method （RSm）. Hardness （Ca/＋） had a positive effect on NZVI reactivity by accelerating iron corrosion. In contrast, alkalinity （bicarbonate; HCO3） and organic matter （humic acid; HA） had negative effects on NZVI reactivity due to morphological change to carbonate green rust, and to competitive adsorption of HA, respectively. The validity of the statistical prediction model derived from RSm was confirmed by an additional confirmation experiment, and the experimental result was within the 95% confidential interval. Therefore, it can be indicated that the RSm model produced results that were statistically significant.

关键词： nitrate reduction concentrate treatment response surface method nano zero valent iron

OPTImAL ASSEmBLY BY mONOTONIC PROPERTY

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Systems Science and mathematical Sciences 1990年第1期3卷 36-45页

作者：堵丁柱 F.k.hwang Institute of Applied mathematics Academia SinicaBeijingChina AT&T Bell Laboratories Murray HillNew JerseyU.S.A

Consider a system containing a type of n *** device consists of *** mn parts for n devices with different working probabilities,how do we groupthem into n devices such that the system is most reliable.A monotonic grouping means thatthe best parts are put together,then the best remaining parts are put together,etc..Asufficient and necessary condition for such grouping being optimal will be given in *** an application,we show that the monotonic grouping is optimal for the two-stagek-out-of-n *** m=2,we also study the grouping that the best pairs to the worst,the second best pairs to the second worst,etc.,associated with a redundant device problem.

关键词： Reliability k-out-of-n system optimization monotone assignment

L^(p)Boundedness of Fourier Integral Operators in the Class S_(1,0)

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Acta mathematica Sinica,English Series 2023年第1期39卷 37-98页

作者： Ing-Lung hwang Department of mathematics “National Chung Cheng University of Taiwan”Chiayi County 621003China

We prove the following properties:(1)Let a∈Λ_(1,0,k,k’)^(m0)(R^(n)×R^(n))with m0=-1|1/p-1/2|(n-1),n≥2(1 n/p,k’>0;2≤p≤∞,k>n/2,k’>0 respectively).Suppose the phase function S is positively homogeneous inξ-variables,non-degenerate and satisfies certain *** the Fourier integral operator T is L^(p)-*** the method of(1),we can obtain the L^(p)-boundedness of the Fourier integral operator if(2)the symbol a∈Λ_(1,δ,k,k’)^(m0),0≤δ≤1,with m0,k,k’and S given as in(1).Also,the method of(1)gives:(3)a∈Λ_(1,δ,k,k’),0≤δk,k’given as in(1),then the L^(p)-boundedness of the pseudo-differential operators holds,1

关键词： Fourier integral operator L^(p)-boundedness

Isotope Geochemistry of Volcanic Rocks from the Barton Peninsula,king George Island,Antarctica

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Journal of Earth Science 2011年第1期22卷 40-51页

作者： Jeong hwang 郑祥身 Edward m Ripley Jong-Ik Lee Dongbok Shin Department of Geological Engineering Daejeon University Institute of Geology and Geophysics Chinese Academy of Sciences Department of Geological Sciences Indiana University korea Polar Research Institute Department of Geological Sciences Kongju University

C, O, H, S and Sr isotopes were investigated to characterize the isotopic composition of the Paleocene-Eocene volcanic rocks in Barton Peninsula, king George Island, Antarctica. The analyzed samples of volcanic rocks cover a range from basalt to andesite. The δ 13C and 61SO values of calcite in volcanic rocks range from -7.5‰ to -3.2‰ and 0.4‰ to 5.1‰, respectively. The homogenous δ 13C cal and depleted δ18 Ccal values relative to primary magmatic values reflect the effect of high temperature alteration of volcanic rocks. The δ18 O of volcanic rocks ranges from -1.1‰ to 7.2‰, and the majority of values are significantly lower than those of primary magmatic values. The low δ18 O WR values are compatible with high temperature alteration. The initial values of 87Sr/86Sr of volcanic rocks span a narrow range from 0.703 312 to 0.703 504 which belong to the present mid-oceanic ridge basalt. The values of 87Sr/86Sr of volcanics in the Barton Peninsula are similar to those determined in the Fildes Peninsula, king George Island. The δD WR and H2O contents of volcanic rocks range from -74‰ to -66‰ and 0.67 wt.% to 2.74 wt.%, respectively. The higher δD WR and H2O wt.% of volcanic rocks relative to fresh basalts also result from high temperature alteration. Sulfur isotope compositions of the volcanic rocks range from -12.5‰ to -7.0‰; these values may represent fractionation accompanying partial oxidation of magmatic S or incorporation of some bacteriogenic sulfide. The low S contents and negative correlation with C and H2O reflect the formation of calcite and breakdown of sulfide as a result of high temperature water-rock interaction.

关键词： isotope volcanic rock high temperature alteration Antarctica.

Imprinting at the kBTBD6 locus involves species-specific m ternal methylation and monoallelic expression in livestock animals

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Journal of Animal Science and Biotechnology 2024年第1期15卷 127-145页

作者： Jinsoo Ahn In-Sul hwang mi-Ryung Park Seongsoo hwang kichoon Lee Department of Animal Sciences The Ohio State UniversityColumbusOH 43210USA Animal Biotechnology Division Rural Development AdministrationNational Institute of Animal ScienceJeonbuk 55365Republic of Korea Columbia Center for Translational Immunology Columbia University Irving Medical CenterColumbia UniversityNew YorkNY 10032USA Animal Welfare Research Team National Institute of Animal ScienceRDA1500Kongjwipatjwi‑roJeollabuk‑do 55365Republic of Korea

Background The primary differentially methylated regions(DmRs) which are maternally hypermethylated serve as imprinting control regions(ICRs) that drive monoallelic gene expression, and these ICRs have been investigated due to their implications in mammalian development. Although a subset of genes has been identified as imprinted, in-depth comparative approach needs to be developed for identification of species-specific imprinted genes. Here, we examined DNA methylation status and allelic expression at the kBTBD6 locus across species and tissues and explored potential mechanisms of *** Using whole-genome bisulfite sequencing and RNA-sequencing on parthenogenetic and normal porcine embryos, we identified a maternally hypermethylated DmR between the embryos at the kBTBD6 promoter Cp G island and paternal monoallelic expression of kBTBD6. Also, in analyzed domesticated mammals but not in humans, non-human primates and mice, the kBTBD6 promoter Cp G islands were methylated in oocytes and/or allelically methyl-ated in tissues, and monoallelic kBTBD6 expression was observed, indicating livestock-specific imprinting. Further analysis revealed that these Cp G islands were embedded within transcripts in porcine and bovine oocytes which coexisted with an active transcription mark and DNA methylation, implying the presence of transcription-dependent *** In this study, our comparative approach revealed an imprinted expression of the kBTBD6 gene in domesticated mammals, but not in humans, non-human primates, and mice which implicates species-specific evolution of genomic imprinting.

关键词： Differentially methylated region Domesticated mammal Imprinting kBTBD6 Parthenogenetic

Real hypersurfaces in the complex quadric with commuting Ricci tensor

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Science China mathematics 2016年第11期59卷 2185-2198页

作者： SUH YoungJin hwang DooHyun Department of mathematics Kyungpook National University

We introduce the notion of commuting Ricci tensor for real hypersurfaces in the complex quadric Qm = SOm＋2/SOmSO2. It is shown that the commuting Ricci tensor gives that the unit normal vector field N becomes -principal or -isotropic. Then according to each case, we give a complete classification of Hopf real hypersurfaces in Qm = SOm＋2/SOmSO2 with commuting Ricci tensor.

关键词： commuting Ricci tensor -isotropic -principal kahler structure complex conjugation complex quadric

measurement of alumina film induced ablation of internal insulator in solid rocket environment

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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 hwang Yoongoo kang Agency for Defense Development 160488th Bukyuseong-streetDaejeonSouth Korea

This study investigates the ablation of internal insulation induced by the deposition of an alumina film with different lateral film speeds.A sub-scale test solid rocket motor(SRm)was designed in an impinging jet configuration to form an alumina film on the sample and to encourage the lateral movement of the film by a high-speed wall *** static fire tests of the test SRm were conducted with 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 wall jet and the deposition rate of alumina *** ablation velocity was deduced from the difference in the sample thickness after a test using a coordinate measuring *** droplet deposition mass flux and wall jet velocity were obtained via two-phase flow simulation with the same jet velocity and effective *** a result,the characteristics of alumina-induced ablation and the changes in ablation with jet velocities were *** area within0.8×jet diameter was focused upon,where the ratio of ablation velocity to incoming alumina mass was constant for each jet velocity,and showed a similarity in jet *** the ablation velocity was increased from 2.05 to 9.98 mm/s with increasing jet velocity,the ratio of the ablation velocity and alumina mass flux decreased from 1.07×10^(-4)to 0.49×10^(-4)m^(3)/kg as Al_(2)O_(3)-C reactions became less efficient with a reduced residence time of the *** the decrease in residence time by the wall jet is more 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 volumetric rate of ablation per unit mass of alumina.

关键词： Internal insulation Solid rocket motor Ablation Alumina