http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
N. H. Heo,Y.‑U. Heo,S. K. Kwon,N. J. Kim,S.‑J. Kim,H.‑C. Lee 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.2
Extended Hall–Petch relationships for yield (y ), cleavage (cl ) and intergranular fracture (ig) strengths of pure iron havebeen established through the direct calculation of the proportional constant (k) and the estimation of the friction stress (0) . The magnitude orders of k and0 are generally ky< kcl< kig and y0< cl0< ig0 , respectively. Based on the Hall–Petchrelationships, micro-yielding in a bcc steel occurs at the instance that the pile-up dislocations within a specific grain showingthe Schmid factor of 0.5 propagate into the neighboring grain. The initial brittle crack is formed at the instance that the flowstrength exceeds the brittle fracture strength. Once the brittle crack is formed, it grows catastrophically. Due to the smallestand ky andy0 , the cleavage and the intergranular fracture occur always after micro-yielding. The {100} cleavage fracture ofthe steel is due to the lowest theoretical {100} cleavage strength. Due to the thermal components included in cleavage andintergranular fracture strengths, they show also the temperature and strain rate dependence observed in yield strength. Theincrease in susceptibility to brittle fracture with decreasing temperature and increasing strain rate is due to the increase indislocation density which causes the high work hardening rate.
Phase transformation of Cu precipitates from bcc to fcc in Fe-3Si-2Cu alloy
Heo, Y.U.,Kim, Y.K.,Kim, J.S.,Kim, J.K. Elsevier Science 2013 ACTA MATERIALIA Vol.61 No.2
Phase transition of Cu precipitates during aging of an Fe-3Si-2Cu alloy was studied by transmission electron microscopy. The precipitation of 3-5-nm-sized body-centered cubic (bcc) Cu in ferrite matrix was confirmed by high-angle annular dark-field scanning transmission electron microscopy imaging. The bcc Cu precipitates transformed to 9R Cu as they grew. Many 9R Cu precipitates were twinned, but untwinned 9R Cu particles were also observed. The 9R Cu transformed to twinned face-centered cubic (fcc) Cu by the glide of +/-a/3 [100]<SUB>9R</SUB> Shockley-type partial dislocations. Formation of the 3R structure previously reported could not be confirmed in this study. Finally, twins in fcc Cu precipitates disappeared to form stable fcc Cu particles. The importance of electron beam-orientation-dependent moire fringes in the correct identification of Cu structure is discussed in detail.
Heo, Y.U.,Takeguchi, M.,Furuya, K.,Lee, H.C. Elsevier Science 2009 Acta materialia Vol.57 No.4
The transformation of the grain boundary hexagonal close-packed η-Ni<SUB>3</SUB>Ti (DO<SUB>24</SUB>) precipitates to face-centered cubic austenite (γ) was investigated in an Fe-Ni-Ti alloy using transmission electron microscopy. The heterogeneous nucleation of austenite on the (0001) basal plane of the η-Ni<SUB>3</SUB>Ti precipitate was identified. During the growth of the interface austenite, ordered face-centered cubic (fcc) (L1<SUB>2</SUB>) γ'-Ni<SUB>3</SUB>Ti phase was formed in the η-Ni<SUB>3</SUB>Ti by the climbing of the b->=14[0001] edge dislocations. The diffusion of iron from austenite to the γ'-Ni<SUB>3</SUB>Ti phase was detected by electron energy loss spectroscopy analysis, resulting in the disordering of the γ'-Ni<SUB>3</SUB>Ti phase. The transformation sequence is schematically suggested and the transformation mechanism was discussed based on the misfit strain in the η/γ interface.
Lee, Y.J.,Moon, S.U.,Park, M.G.,Jung, W.Y.,Park, Y.K.,Song, S.K.,Ryu, J.G.,Lee, Y.S.,Heo, H.J.,Gu, H.N.,Cho, S.J.,Ali, B.A.,Al-Khedhairy, A.A.,Lee, I.,Kim, S. IPC Science and Technology Press 2016 Biomaterials Vol.101 No.-
<P>Recently, PIWI-interacting small non-coding RNAs (piRNAs) have emerged as novel cancer biomarkers candidate because of their high expression level in various cancer types and role in the control of tumor suppressor genes. In this study, a novel breast cancer theragnostics probe based on a single system targeting the piRNA-36026 (piR-36026) molecular pathway was developed using a piR-36026 molecular beacon (MB). The piR-36026 MB successfully visualized endogenous piR-36026 biogenesis, which is highly expressed in MCF7 cells (a human breast cancer cell line), and simultaneously inhibited piR-36026-mediated cancer progression in vitro and in vivo. We discovered two tumor suppressor proteins, SERPINA1 and LRAT, that were directly regulated as endogenous piR-36026 target genes in MCF7 cells. Furthermore, multiplex bioimaging of a single MCF7 cell following treatment with piR-36026 MB clearly visualized the direct molecular interaction of piRNA-36026 with SERPINAI or LRAT and subsequent molecular therapeutic responses including caspase-3 and PI in the nucleus. (C) 2016 Elsevier Ltd. All rights reserved.</P>