http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Mullane, Kimberly C.,Ryu, Ho,Cheisson, Thibault,Grant, Lauren N.,Park, Ji Young,Manor, Brian C.,Carroll, Patrick J.,Baik, Mu-Hyun,Mindiola, Daniel J.,Schelter, Eric J. American Chemical Society 2018 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.140 No.36
<P>Uranium complexes in the +3 and +4 oxidation states were prepared using the anionic PN<SUP>-</SUP> (PN<SUP>-</SUP> = (<I>N</I>-(2-(diisopropylphosphino)-4-methylphenyl)-2,4,6-trimethylanilide) ligand framework. New complexes include the halide starting materials, (PN)<SUB>2</SUB>U<SUP>III</SUP>I (<B>1</B>) and (PN)<SUB>2</SUB>U<SUP>IV</SUP>Cl<SUB>2</SUB> (<B>2</B>), which both yield (PN)<SUB>2</SUB>U<SUP>IV</SUP>(N<SUB>3</SUB>)<SUB>2</SUB> (<B>3</B>) by reaction with NaN<SUB>3</SUB>. Compound <B>3</B> was reduced with potassium graphite to produce a putative, transient uranium-nitrido moiety that underwent an intramolecular C-H activation to form a rare example of a parent imido complex, [K(THF)<SUB>3</SUB>][(PN)U<SUP>IV</SUP>(═NH)[<SUP><I>i</I></SUP>Pr<SUB>2</SUB>P(C<SUB>6</SUB>H<SUB>3</SUB>Me)N(C<SUB>6</SUB>H<SUB>2</SUB>Me<SUB>2</SUB>CH<SUB>2</SUB>)]] (<B>4</B>). Calculated reaction energy profiles strongly suggest that a C-H insertion becomes unfavorable when a reductant is present, offering a distinctively different reaction pathway than previously observed for other uranium nitride complexes.</P> [FIG OMISSION]</BR>
matte kishore babu,Ho-Girl Lee,A. Gezaei Abera,H. J. Kim,C. S. Seok,S. J. Song 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.1
Adoption of thermal barrier coatings (TBC) will help to improve the durability and thermal efficiency of turbine engines. Delamination of TBC owing to thermally grown metal oxides is a critical issue that needs periodical evaluation to ensure safety and effective maintenance for the financial benefits of industry. In this paper, a methodical approach using ultrasonic C-scan technique for quantitative evaluation of partial delamination area in TBC specimens was investigated. Preliminary studies were conducted using acoustic simulations and the experiments were carried out on a set of coin shaped TBC specimens prepared using plasma spray technique and isothermally degraded at 1100 °C for 25 h, 50 h, 100 h, and 150 h. Ultrasonic C-scans were performed using pulse echo technique with incident ultra sound radiation inclined normal to the surface of base metal of TBC system. Delamination maps of respective specimens were formulated from ultrasonic signals through proper signal processing and analysis techniques and the degree of delamination was evaluated with the help of existed mathematical model. The simulation results shows good agreement with the experimental data and this approach shows ability to estimate the degree of delamination from base metal surface.
장민수,이형철,박영한,이수대,노지현,허필화,김장환 부산대학교 물성연구소 1986 물성연구소연구논문집 Vol.5 No.-
Czochralski 방법으로 Bi₂(Mo0₄)₃ 單結晶을 育成하였으며, 이때 最適育成條件은 1.9∼2.0 mm/hr 引上速度와 12∼13 rpm의 回轉速度가 적합하였다. Bi₂(MoO₄)₃ 單結晶의 단위포는 X-ray 回折法에 의하여 실온에서 Monoclinic 임이 밝혀졌다. 이 結晶에 대한 電氣的 性質의 溫度 依存性을 조사한 결과, 相轉移성이 475±5℃근처에 존재함을 알 수 있었다. A single crystal of Bi₂(MoO₄)₃is grown using the Czochralski method. The optimum growing conditions are obtained with the pulling speed of 1.9-2.0 mm/hr and the rotation speed of 12-13 rpm. The crystal unit cell of Bi₂(MoO₄)₃is determined to be Monoclinic in room temperature by X-ray diffraction method. Through the temperature dependence study of electrical characteristics for this crystal, the phase transition point is found to be around 475±5℃.
S. E. Moon,Bae Ho Park,E.-K Kim,H.-C. Ryu,H.-Y. Lee,J. Park,K.-H. Park,K.-Y. Kang,M.-H. Kwak,S.-J. Lee,Y.-T. Kim 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.II
Oriented (Ba$_{0.6}$,Sr$_{0.4}$)TiO$_3$ (BST60) and graded (Ba,Sr)TiO$_3$ (BST) films were deposited on MgO (001) single crystals by using a pulsed laser deposition method. Structural properties of the films were investigated by using an X-ray diffractometer. The dielectric properties of the films were investigated under a dc bias field of 0 $-$ 20 V in the temperature region from 173 to 393 K by using interdigital capacitors (IDC) fabricated by photolithography and an etching process. The temperature-dependent small-signal dielectric properties of the films were measured with a Keithley 590 C-V meter. The measured temperature-dependent tunability for an IDC device based on BST60/MgO, BT/$\cdot\cdot$/ST/MgO and ST/$\cdot\cdot$/BT/MgO multilayer structure showed interesting data. The trends of the dielectric properties of the IDC may be due to the fact that they are affected by Curie temperature, lattice constant, strain/stress, {\it etc.}
Sung Kim,Suk-Ho Choi,C. J. Park,H. Y. Cho,K. H. Cho,R. G. Elliman 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.3
The structural and the optical properties of Ge nanocrystals (NCs) showing large capacitancevoltage hysteresis have been studied by using infrared photoluminescence (PL), high-resolution transmission electron microscopy (HRTEM), high-resolution X-ray diraction (HRXRD). The memory eect strongly depends on the implant dose, the oxide thickness, and the annealing temperature in metal-oxide-semiconductor devices containing Ge NCs. Well-defined C-V characteristics with large hysteresis are found only for annealing temperatures 950 C where Ge NCs are known to form. HRTEM demonstrates the existence of Ge NCs which are almost aligned at an average distance of about 6.7 nm from the SiO2/Si interface. This suggests that the memory eect can be enhanced by accurately controlling the distribution of Ge NCs with respect to the Si/SiO2 interface, although it is also influenced by implantation-induced deep-level defects and SiGe complexes formed at the interface, as confirmed by PL and HRXRD.
Direct Reprogramming of Fibroblasts into Neural Stem Cells by Defined Factors
Han, D.,Tapia, N.,Hermann, A.,Hemmer, K.,Hoing, S.,Arauzo-Bravo, Marcos J.,Zaehres, H.,Wu, G.,Frank, S.,Moritz, S.,Greber, B.,Yang, J.,Lee, H.,Schwamborn, Jens C.,Storch, A.,Scholer, Hans R. Cell Press 2012 Cell stem cell Vol.10 No.4
Recent studies have shown that defined sets of transcription factors can directly reprogram differentiated somatic cells to a different differentiated cell type without passing through a pluripotent state, but the restricted proliferative and lineage potential of the resulting cells limits the scope of their potential applications. Here we show that a combination of transcription factors (Brn4/Pou3f4, Sox2, Klf4, c-Myc, plus E47/Tcf3) induces mouse fibroblasts to directly acquire a neural stem cell identity-which we term as induced neural stem cells (iNSCs). Direct reprogramming of fibroblasts into iNSCs is a gradual process in which the donor transcriptional program is silenced over time. iNSCs exhibit cell morphology, gene expression, epigenetic features, differentiation potential, and self-renewing capacity, as well as in vitro and in vivo functionality similar to those of wild-type NSCs. We conclude that differentiated cells can be reprogrammed directly into specific somatic stem cell types by defined sets of specific transcription factors.
Limjuco, Lawrence A.,Nisola, Grace M.,Torrejos, Rey Eliseo C.,Han, Jeong Woo,Song, Ho Seong,Parohinog, Khino J.,Koo, Sangho,Lee, Seong-Poong,Chung, Wook-Jin American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.49
<P>Crown ether (CE)-based Li+ adsorbent micro fibers (MFs) were successfully fabricated through a combined use of CE diols, electrospinning, and aerosol cross-linking. The 14- to 16-membered CEs, with varied ring subunits and cavity dimensions, have two hydroxyl groups for covalent attachments to poly(vinyl alcohol) (PVA) as the chosen matrix. The CE diols were blended with PVA and transformed into microfibers via electrospinning, a highly effective technique in minimizing CE loss during MF fabrication. Subsequent aerosol glutaraldehyde (GA) cross-linking of the electrospun CE/PVA MFs stabilized the adsorbents in water. The aerosol technique is highly effective in cross-linking the MFs at short time (5 h) with minimal volume requirement of GA solution (2.4 mL g(-1) MF). GA cross-linking alleviated CE leakage from the fibers as the CEs were securely attached with PVA through covalent CE GA PVA linkages. Three types of CE/PVA MFs were fabricated and characterized through Fourier transform infrared-attenuated total reflection, C-13 cross-polarization magic angle spinning NMR, field emission scanning electron microscope, N-2 adsorption/desorption, and universal testing machine. The MFs exhibited pseudo-second-order rate and Langmuir-type Li+ adsorption. At their saturated states, the MFs were able to use 90-99% CEs for 1:1 Li+ complexation, suggesting favorability of their microfibrous structures for CE accessibility to Lit. The MFs were highly Li+ selective in seawater. Neopentyl-bearing CE was most effective in blocking larger monovalents Na+ and K+, whereas the dibenzo CE was best in discriminating divalents Mg2+ and Ca2+. Experimental selectivity trends concur with the reaction enthalpies from density functional theory calculations, confirming the influence of CE structures and cavity dimensions in their 'size-match' Li+ selectivity.</P>
C.T. Hsieh,M.W. Lin,C.L. Chang,Y.C. Ho,S.Y. Chen,J. Wang,M.C. Chou,J.Y. Lin,C.H. Pai,P.H. Lin,L.C. Tai,S.H. Chen,G.Y. Tsaur,C.C. Kuo,T.Y. Chien 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.6
A general method for fabricating transient plasma structures with high-intensity laser pulses is developed to gain fine control over laser-plasma interactions. These structures have been used as programmable photonic devices in the development of laser-wakefield accelerators, soft X-ray lasers and plasma nonlinear optics driven by multi-terawatt laser pulses. Plasma ramps are used to control electron injection in laser-wakefield accelerators, plasma waveguides are used to enhance the efficiency of soft X-ray lasers by orders of magnitude and periodic plasma structures are used to achieve quasi-phase matching in relativistic harmonic generation. By scanning the interaction length with the same plasma-fabrication method, tomographic measurements are carried out to resolve the injection/acceleration process in laser-wakefield accelerators and amplification processes in X-ray lasers and relativistic harmonic generation. A theoretical analysis and a computer simulation are also carried out to provide insightful pictures of these processes. These research works show that by controlling plasma structures with optical fabrication methods, laser-plasma interaction can be engineered to expand and enrich the frontier of high-field physics.
Choy, Jin-Ho,Kim, Seung-Joo,Park, J.C.,Frohlich, K.,Dordor, P.,Grenier, J.C. Korean Chemical Society 1990 Bulletin of the Korean Chemical Society Vol.11 No.6
A.c. susceptibility for $Bi_{1.4}Pb_{0.6}Sr_2Ca_2Cu_{3.6}O_x$ superconductor is measured as a function of temperature at different value of a.c. magnetic field amplitude. Two transition steps are attributed to the intergranular and intragranular properties. Based on Bean's critical state model, intergranular critical current density, $J_c^{gb}$ (11 $A/cm^2$ at 77 K) and intragranular critical current density, $J_c^g (7{\times}10^3\;A/cm^2$ at 100 K) are estimated. The low values of $J_c^{gb}$and $J_c^g$ reflect a poor nature of coupling between grains and the low pinning force density of intragrain in $Bi_{1.4}Pb_{0.6}Sr_2Ca_2Cu_{3.6}O_x$ superconductor.