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91.
A technology credit guarantee policy has been established to provide financial support to technology-based SMEs with a limited asset base. For an effective technology credit guarantee policy, risk management is essential. In this paper, we investigate a survival model that predicts start-up SMEs’ loan default probability at a given time based on technology attributes along with the economic environment and the firm’s characteristics at the time of the technology credit guarantee fund application. This, in turn, is used for the estimation of the technology fund risk along with a stress test. Our work is expected to contribute to reducing the risks associated with technology financing. 相似文献
92.
Jae-Myung Lee Won-Seok Chang Byeong-Chul Yu Hansu Kim Dongmin Im Seok-Gwang Doo Hun-Joon Sohn 《Electrochemistry communications》2010,12(7):928-932
A Sn2Fe/C nanocomposite containing Cu was evaluated as an anode material for rechargeable lithium-ion batteries. The electrochemical reaction mechanism of this nanocomposite was examined by ex-situ X-ray diffraction and high resolution transmission electron microscopy. The Sn2Fe/C nanocomposite containing Cu showed dramatically improved cycling performance. The enhanced cyclability of the Sn2Fe/C nanocomposite containing Cu was attributed to both amorphization of the Sn2Fe phase and a recombination reaction between Sn and Cu during the charging step. 相似文献
93.
A quantitative analysis method of fluorine in the slags produced in the stainless argon–oxygen decarburization (AOD) process by X‐ray spectrometry was proposed employing direct analysis technique by pressed pellet. This research investigated the separate quantification of calcium fluoride and calcium oxide contained in AOD slags. X‐ray diffraction measurement was performed to identify the stable phase of fluorine compound, which is primarily present in the slags. The synthetic standards prepared in laboratory were used to construct the X‐ray fluorescence (XRF) calibration curves for F, CatO, SiO2, MgO, Al2O3 and Cr2O3, considering the matrix effects and line overlap corrections (t: total). The calibration curves were tested by the quantitative analysis of synthetic standards with satisfactory precision and accuracy. The proposed method might be an alternative solution to the problem with the simple and routine chemical analyses of calcium fluoride in AOD slags of stainless steelmaking process by XRF spectrometry. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
94.
Sung Hee Yoon Sun Ok Yun Jung Yong Park Hee Yeun Won Eun-Kyung Kim Hyun-Jung Sohn Hyun-Il Cho Tai-Gyu Kim 《Experimental & molecular medicine》2009,41(3):161-170
Increasing importance is being given to the stimulation of Th1 response in cancer immunotherapy because its presence can shift the direction of adaptive immune responses toward protective immunity. Based on chemokine receptor expression, CXCR3+CCR4-CD4+ T cells as Th1-type cells were investigated its capacity in monocyte-derived dendritic cell (DC) maturation and polarization, and induction of antigen specific cytotoxic T lymphocytes (CTL) in vitro. The levels of IL-4, IL-5 and IL-10 were decreased to the basal level compared with high production of IFN-γ, TNF-α, and IL-2 in CXCR3+CCR4-CD4+ T cells stimulated with anti-CD3 and anti-CD28 antibodies. Co-incubation of activated CD4+ or CXCR3+CCR4-CD4+ T cells with DC (CD4+/DC or CXCR3+CD4+/DC, respectively) particularly up-regulated IL-12 and CD80 expression compared with DC matured with TNF-α and LPS (mDC). Although there was no significant difference between the effects of the CXCR3+CCR4-CD4+ and CD4+ T cells on DC phenotype expression, CXCR3+CD4+/DC in CTL culture were able to expand number of CD8+ T cells and increased frequencies of IFN-γ secreting cells and overall cytolytic activity against tumor antigen WT-1. These results demonstrated that the selective addition of CXCR3+CCR4-CD4+ T cells to CTL cultures could enhance the induction of CTLs by DC in vitro, and implicated on a novel strategy for adoptive T cell therapy. 相似文献
95.
The lithia formation mechanism in tin oxide anode is investigated using electrochemical measurements and Auger spectroscopy. Based on the charge/discharge capacities for SnO electrode, the atomic ratio of Li to O in lithia is less than 2 at the discharge capacity of 400 mAh/g (~0.9 V). The derivative capacity plots show that the irreversible reaction occurs throughout the entire discharge to 0 V, and the atomic ratio of Li to O is about 1 at ~0.8 V and 2 at 0 V. Auger spectroscopy analysis also confirms that the atomic ratio of Li to O approaches to 2 only when discharged to 0 V. Thus, Li2O appears to have formed at 0 V in the first discharge, not ~0.8 V as reported previously, such that the initial lithia composition is more like Li2O2. 相似文献
96.
Cheol-Min Park Won-Seok Chang Heechul Jung Jae-Hun Kim Hun-Joon Sohn 《Electrochemistry communications》2009,11(11):2165-2168
A nanostructured Sn/TiO2/C composite was prepared from SnO, Ti, and carbon powders using a mechanochemical reduction method and evaluated as an anode material in rechargeable Li-ion batteries. The Sn/TiO2/C nanocomposite was composed of uniformly dispersed nanocrystalline Sn and rutile TiO2 in amorphous carbon matrix. In addition, electrochemical Li insertion/extraction in rutile TiO2 was examined by ex situ XRD and extended X-ray absorption fine structure. The Sn/TiO2/C nanocomposite exhibited excellent electrochemical performance, which highlights its potential as a new alternative anode material in Li-ion batteries. 相似文献
97.
Jinyoung Kim Docheon Ahn Chandramouli Kulshreshtha Kee‐Sun Sohn Namsoo Shin 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(4):i14-i16
The structure of lithium barium silicate, Li2BaSiO4, has been determined from synchrotron radiation powder data. The title compound was synthesized by high‐temperature solid‐state reaction and crystallizes in the hexagonal space group P63cm. It contains two Li atoms, one Ba atom (both site symmetry ..m on special position 6c), two Si atoms [on special positions 4b (site symmetry 3..) and 2a (site symmetry 3.m)] and four O atoms (one on general position 12d, and three on special positions 6c, 4b and 2a). The basic units of the structure are (Li6SiO13)5− units, each comprising seven tetrahedra sharing edges and vertices. These basic units are connected by sharing corners parallel to [001] and through sharing (SiO4)4− tetrahedra in (001). The relationship between the structures and luminescence properties of Li2SrSiO4, Li2CaSiO4 and the title compound is discussed. 相似文献
98.
Krishnan S Ward RJ Hexemer A Sohn KE Lee KL Angert ER Fischer DA Kramer EJ Ober CK 《Langmuir : the ACS journal of surfaces and colloids》2006,22(26):11255-11266
Polystyrene-b-poly(4-vinylpyridine) copolymers were quaternized with 1-bromohexane and 6-perfluorooctyl-1-bromohexane. Surfaces prepared from these polymers were characterized by contact angle measurements, near-edge X-ray absorption fine structure spectroscopy and X-ray photoelectron spectroscopy. The fluorinated pyridinium surfaces showed enhanced antibacterial activity compared to their nonfluorinated counterparts. Even a polymer with a relatively low molecular weight pyridinium block showed high antimicrobial activity. The bactericidal effect was found to be related to the molecular composition and organization in the top 2-3 nm of the surface and increased with increasing hydrophilicity and pyridinium concentration of the surface. 相似文献
99.
Described are general protocols for the rapid construction of various C-15-substituted analogues of vindoline using palladium-catalyzed cross-coupling reactions. The required bromo- and iodovindolines were prepared in high yield by the reaction of vindoline with N-bromosuccinimide or N-iodosuccinimide, respectively. The study not only led to the preparation of a number of structurally novel vindoline analogues but also opens the door to new strategies for the synthesis of vinblastine, vincristine, and related anticancer agents. Also described is the conversion of ent-tabersonine to ent-vindoline. 相似文献
100.
Proper maintenance of fighter aircraft is an important issue to control theairpower. Typical maintenance policy applied is based on the constant schedulefor a given module. This kind of maintenance does not take into account varyingcharacteristics of the module over time. In this paper, we utilize the randomeffects Weibull regression model for non-constant MTBF (mean time betweenfailure) and MTTR (mean time to repair) in order to provide a dynamic preventivemaintenance schedule reflecting the module's varying characteristics in atimely manner. Our study is expected to contribute to ROKA (Republic of KoreaAirforce) in terms of improving the level of combat readiness of fighteraircraft. 相似文献