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61.
Tae Woo Kim Hana Yoo In Young Kim Hyung‐Wook Ha Ah Reum Han Jong‐San Chang Ji Sun Lee Seong‐Ju Hwang 《Advanced functional materials》2011,21(12):2301-2310
Manganese oxide nanocrystals are combined with aluminum oxide nanocrystals to improve their crystallinity via calcination without a significant increase of crystal size. A nanocomposite, consisting of two metal oxides, can be synthesized by the reaction between permanganate anions and aluminum oxyhydroxide keggin cations. The as‐prepared manganese oxide–aluminum oxide nanocomposite is X‐ray amorphous whereas heat‐treatment gives rise to the crystallization of an α‐MnO2 phase at 600 °C and Mn3O4/Mn2O3 and γ‐Al2O3 phases at 800 °C. Electron microscopy and N2 adsorption‐desorption‐isotherm analysis clearly demonstrate that the as‐prepared nanocomposite is composed of a porous assembly of monodisperse primary particles with a size of ~20 nm and a surface area of >410 m2 g?1. Of particular interest is that the small particle size of the as‐prepared nanocomposite is well‐maintained up to 600 °C, a result of the prevention of the growth of manganate grains through nanoscale mixing with alumina grains. The calcined nanocomposite shows very‐high catalytic activity for the oxidation of cyclohexene with an extremely high conversion efficiency of >95% within 15 min. The present results show that the improvement of the crystallinity without significant crystal growth is very crucial for optimizing the catalytic activity of manganese oxide nanocrystals. 相似文献
62.
Vivanti Giacomo; McCormick Carolyn; Young Gregory S.; Abucayan Floridette; Hatt Naomi; Nadig Aparna; Ozonoff Sally; Rogers Sally J. 《Canadian Metallurgical Quarterly》2011,47(3):841
Typically developing children understand and predict others' behavior by extracting and processing relevant information such as the logic of their actions within the situational constraints and the intentions conveyed by their gaze direction and emotional expressions. Children with autism have difficulties understanding and predicting others' actions. With the use of eye tracking and behavioral measures, we investigated action understanding mechanisms used by 18 children with autism and a well-matched group of 18 typically developing children. Results showed that children with autism (a) consider situational constraints in order to understand the logic of an agent's action and (b) show typical usage of the agent's emotional expressions to infer his or her intentions. We found (c) subtle atypicalities in the way children with autism respond to an agent's direct gaze and (d) marked impairments in their ability to attend to and interpret referential cues such as a head turn for understanding an agent's intentions. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
63.
This study describes the development process of Kor-Factor, which is a novel composite evaluation index that was developed to promote Korean domestic academic journals. As more data accumulate, the Kor-Factor’s optimization process was modified in an attempt to address possible drawbacks of the original form; the result is presented in this study. This study compares Kor-Factor with the Impact Factor, which is the most well-known single element evaluation index. We found that Kor-Factor demonstrates a better power of differentiation and a greater capacity to reflect the reputability of key journals. The modified Kor-Factor, which has been developed through an optimization process, reveals a greater power of differentiation than the original Kor-Factor; however, the modified version has less capacity to reflect reputability. The evaluation elements of the modified Kor-Factor are better and are more evenly reflected on the index value than those of the original version. Finally, we propose the establishment of an appropriate data measurement period for the actual application of the index. 相似文献
64.
The notion of a BCK-valued function on a set is introduced, and related properties are investigated. Codes generated by BCK-valued functions are established. 相似文献
65.
K. Young T. Ouchi B. Reichman W. Mays R. Regmi G. Lawes M.A. Fetcenko A. Wu 《Journal of Alloys and Compounds》2010,489(1):202-210
The structural, electrochemical, and gas phase hydrogen storage properties of predominantly C14 crystalline phase alloys with partial replacement by Co (up to 2.5 at%) are reported. Minor phases, including C15 and cubic TiNi, were found by X-ray diffraction and contributed to the improved hydrogen diffusion through the alloy. The optimal Co-content of between 1.0 and 1.5 at% provides easy activation, high gas phase capacity, and a high discharge capacity. An optimized alloy formula also provided the smallest metallic nickel cluster size embedded in the surface oxide and the largest number of nickel clusters. In sealed cell studies, a Co-content of 1.5% gives the best performance in formation, cycle life, and charge retention, but has worse specific power and low temperature performance than some other compositions. The high-rate dischargeabilities at lower rates were found to be limited by surface reactions, not bulk diffusion. 相似文献
66.
Nac‐Woo Kim Byung‐Tak Lee Young‐Sun Kim 《International Journal of Communication Systems》2013,26(11):1382-1394
In this paper, we propose a personally customizable content authoring service (C2Channel) using an Internet Protocol television (IPTV) platform, in which a user terminal such as a PC or set‐top box sends various kinds of multimedia files from a camera or camcorder to a remotely located authoring server (C2Channel server). The C2Channel server creates personalized content in real time by combining special effects with the multimedia files transmitted from the user terminal and then retransmits them to a predefined relevant service group as a personal IPTV channel through an IPTV network provider. This content authoring service supplies an automatic multimedia editing/composition service and offers unicast, multicast, and groupcast services for a large number of interested groups via an IPTV‐based real‐time media delivery platform (Open Live IPTV Engine [OLIVE]), in which a service management server is used for user identification through the IPTV personal channel. Because this platform uses a remote server resource when authoring personally customizable content, resources remaining at the user's terminal can be variously utilized. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
67.
Gyeonghye Yim Seounghun Kang Hyungjun Kim Young‐Jin Kim Yeong‐Gyu Gil Young‐Kwan Kim Dal‐Hee Min Hongje Jang 《Advanced functional materials》2020,30(9)
The synthesis of nanostructures using homogeneous precursors in the solution phase is widely used to achieve uniformity and well‐defined morphological control. However, drawbacks such as the lack of diversity due to the limited reaction rate modulation exist. One‐step, core–shell nanorod formation using simultaneous covering synthesis using solid and ionic heterogeneous precursors is proposed in this study. A Te‐Bi2Te3/TeO2 core–shell structure is successfully synthesized by precisely controlling various influencing factors, including concentration, temperature, and pH, and its physicochemical and photochemical properties are thoroughly investigated. The proposed nanostructure overcomes the oxidation susceptibility of Te and can be applied to multipotent cancer theranostics in vitro and in vivo in combination with computed tomography imaging. 相似文献
68.
Kwang Su Kim Jong Uk Kim Sori Lee Ju Seung Lee Young Jin Jo Byeonghak Park Hyowon Tak Pil J. Yoo Tae‐il Kim 《Advanced functional materials》2017,27(38)
Nanofabrication is an indispensable process in nanoscience and nanotechnology. Unconventional lithographic techniques are often used for fabrication as alternatives to photolithography because they are faster, more cost‐effective, and simpler to use. However, these techniques are limited in scalability and utility because of the collapse of preprinted structures during step‐and‐repeat processes. This study proposes a new class of temperature‐controllable polymeric molds that are coated with a metal such that any site‐specific patterning can be accomplished in a programmable manner using selective contact‐dewetting lithography. The lithography allows sub‐100 nm patterning, step‐and‐repeat processing, and hierarchical structure fabrication. The programmable feature of the lithography can be utilized for the structural coloring and shaping of objects. Large‐area programmable patterning, semiconductor device manufacturing, and the fabrication of iridescent security devices would benefit from the unique features of the proposed strategy. 相似文献
69.
Analytic modeling and computational simulation for the protection of DTV from cognitive radio interference are performed. Protection is achieved by using the protection ratio, which is derived through system modeling and its analysis. On the frequency coordination between digital TV and cognitive radio, an analysis in a co‐channel environment, in a rural area in Korea, is performed. 相似文献
70.
Stable single-frequency fiber ring laser for 25-GHz ITU-T grids utilizing saturable absorber filter 总被引:1,自引:0,他引:1
Han Young Ryu Won-Kyu Lee Han Seb Moon Seung Kwan Kim Ho Suhng Suh Donghan Lee 《Photonics Technology Letters, IEEE》2005,17(9):1824-1826
A stable single-frequency fiber ring laser is proposed that operates in a single mode for more than an hour by incorporating unpumped erbium-doped fiber (EDF) as a saturable absorber filter and optimizing the length of EDF used as gain medium. This laser can be continuously tuned to 25-GHz spacing that precisely matches the ITU-T grids by temperature control of etalon filter. This laser had a signal-to-source spontaneous emission ratio higher than 70 dB, and lasing frequencies of 361 channels was matched to ITU-T grids with excellent flatness. Frequency offset from the ITU-T grid was less than 0.14 GHz. The linewidth and the relative intensity noise value was less than 1.3 kHz and 130 dB/Hz (above 250 kHz), respectively. 相似文献