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91.
Jian-Shan Ye Hui-Fang Cui Ying Wen Wei De Zhang Guo Qin Xu Fwu-Shan Sheu 《Mikrochimica acta》2006,152(3-4):267-275
Platinum (Pt) nanoparticles were deposited at the surface of well-aligned multi-walled carbon nanotubes (MWNTs) by potential
cycling between +0.50 and −0.70 V at a scanning rate of 50 mV · s−1 in 5 mM Na2PtCl6 solution containing 0.1 M NaCl. The electrocatalytic oxidation of methanol at the nanocomposites of Pt nanoparticles/nanotubes
(Ptnano/MWNTs) has been investigated using 0.2 M H2SO4 as supporting electrolyte. The effects of various parameters, such as Pt loading, concentration of methanol, medium temperature
as well as the stability of Ptnano/MWNTs electrode, have been studied. Compared to glassy carbon electrode, carbon nanotube electrode significantly enhances
the catalytic efficiency of Pt nanoparticles for methanol oxidation. This improvement in performance is due not only to the
high surface area and the fast electron transfer rate of nanotubes but also to the highly dispersed Pt nanoparticles as electrocatalysts
at the tips and the sidewalls of nanotubes. 相似文献
92.
Atallah F. Ahmed Ming‐Hsuan Wu Yang‐Chang Wu Chang‐Feng Dai Jyh‐Horng Sheu 《中国化学会会志》2006,53(2):489-494
The metabolites, (24S)‐3β‐acetoxyergost‐5‐en‐21‐oic acid ( 2 ), 5′‐O‐acetylthymidine ( 3 ), 3′‐O‐acetylthymidine ( 4 ), and p‐vinylbenzyl alcohol ( 5 ), along with a known steroid ( 1 ) were isolated from the EtOAc extract of the Formosan soft coral Caldiella australis. The structures of new metabolites were determined on the basis of spectroscopic (including 1D and 2D NMR) analyses and by comparison of their NMR spectral data with those of related compounds. Except for 3 , all compounds exhibited cytotoxic activity of various degrees of potency against a limited panel of human liver and breast cancer cell lines. 相似文献
93.
The electrochemical behavior of RuS2 has been studied using cyclic voltammetry and Energy Dispersive X-ray Spectroscopy (EDX) techniques. Cyclic voltammograms reveal one major anodic peak and two major cathodic peaks on the reverse sweep; these peaks are attributed to the electroadsorption/desorption of OH? groups on the electrode surface. It is proposed that the electroadsorption of the OH? group on RuS2 is due to the presence of Ru 4d electrons in the uppermost part of the valence band. Thus, OH? is oxidized by holes on Ru 4d states in the first step. These groups are transferred to S22?sites in the second step. EDX surface analysis reveals preferential release of S22? from the pyrite lattice. A mechanism for the anodic dissolution of RuS2 is proposed, according to which elemental sulfur is not a direct product, but rather the end product which forms from thiosulfate. 相似文献
94.
Horng Y. Tang Hsiao Y. Lin Ming Y. Liao Jean L. Liu Hwo S. Sheu 《Journal of solid state chemistry》2006,179(8):2728-2731
Bilayer hydrated Na0.35CoO2·1.3H2O structure has re-directed superconductivity research in recent years. Here, we develop a low temperature synthesis method to prepare a novel hydrous Cs0.2CoO2·0.63H2O compound in one step. The bilayer-hydrate of Cs0.2CoO2·0.63H2O with a greatest interlayer spacing d=10.0(2) Å among alkali cobalt oxides has been grown in crystal form. Magnetic susceptibility measurement of Cs0.2CoO2·0.63H2O displays a paramagnetic behavior down to 1.9 K. With the assistance of low temperature molten CsOH solvent, crystals of Rb0.30CoO2·0.36H2O and K0.35CoO2·0.4H2O can be grown. The results provide the capability for preparing a novel hydrous structure and the systematic investigation of interlayer coupling effect of alkali ion insertion compounds. 相似文献
95.
Mono- and bi-nuclear iron(III) complexes of general formula [FeXL] and [LFe-Y-FeL](Bph4)2 have been prepared, and their spin state of iron atom in the complexes has been studied by means of the temperature dependence of the Mössbauer spectra, electronic spectra and magnetic measurement, where X is a mono- dentate ligand such as Cl-, NCS-, NCO-, N3-, pyridine and L denotes a quinquedentate Schiff base derived from salicylaldehyde and diethylenetriamine, and Y denotes bridged ligand such as pyrazine(pyr), 4,4′-bipyridine(bpy) and 4,4′-vinylenebipyridine(vibpy). On the basis of the Mössbauer and magnetic data, it was concluded that these complexes were all the high-spin (S = 5/2) slate. The effect of gamma ray irradiation for these complexes has been discussed. 相似文献
96.
Abstract Single crystals and polycrystalline samples of the compounds bis(1,3-di(p-n-octylphenyl)propane-l,3-dionato)copper(II) [I], and bis(l,3-di(p-n-octyloxy-phenyl)propane-l,3-dionato)copper(II) [II] have been studied by E.S.R. The E.S.R. spectra of single crystals of [I] at 298 K have the features associated with a spin 1/2 one-dimensional Heisenberg antiferromagnet while the spectra of single crystals of [II] do not. E.S.R. of single crystals of [I] and [II] provides a reliable means of detecting previously reported crystalline to discotic phase transitions. Single crystals of [I] heated beyond the temperature of the first discotic phase transition yield single line E.S.R. spectra which have an angular dependence and an asymmetric lineshape; these observations suggest that, in the discotic phase, exchange interactions are still significant and a degree of long range order is maintained. 相似文献
97.
This paper presents a hybrid neuro-fuzzy methodology to identify appropriate global logistics (GL) operational modes used for global supply chain management. The proposed methodological framework includes three main developmental phases: (1) establishment of a GL strategic hierarchy, (2) formulation of GL-mode identification rules, and (3) development of a GL-mode choice model. By integrating advanced multi-criteria decision-making (MCDM) techniques including fuzzy analytical hierarchy process (Fuzzy-AHP), Fuzzy-MCDM, and the technique for order preference by similarity to an ideal solution (TOPSIS), six types of global logistics and operational modes coupled with corresponding fuzzy-based multi-criteria decision-making rules are specified in the second phase. Using the specified fuzzy decision-making rules as the input database, an adaptive neuro-fuzzy inference system (ANFIS) is then developed in the third phase to identify proper GL modes for the implementation of global supply chain management. A numerical study with a questionnaire survey database aimed at the information technology (IT) industries of Taiwan is conducted to illustrate the applicability of the proposed method. 相似文献
98.
Jyh-Chen Chen Gwo-Jiun Sheu Farn-Shiun Hwu Hsueh-I Chen Jinn-Kong Sheu Tsung-Xian Lee Ching-Cherng Sun 《Optical Review》2009,16(2):213-215
The effects of current distribution in LED chips on the electrical potential and optical light extraction efficiency are investigated
by a numerical simulation. The results show that when the resistivity of the current-spreading layer is decreased there is
current-crowding near the n-contact. On the other hand, when the resistivity in the current-spreading layer increases, there
is current-crowding near the p-contact. When the current is crowded near the n-contact due to less resistivity of the current-spreading
layer, the input power is lower because of the smaller series resistance in the chip, and the light extraction efficiency
is higher since the shadowing effect of the p-contact can be avoided. For L
p = 50 μm in this study, the light extraction efficiency at ρ
ITO = 0.1 × 10−3 Ω·cm is 1.4 times better than that when L
p = 100 μm, even though the driving voltage is raised 1.02 times. 相似文献
99.
Yen‐Ju Tseng Atallah F. Ahmed Chi‐Hsin Hsu Jui‐Hsin Su Chang‐Feng Dai Jyh‐Horng Sheu 《中国化学会会志》2007,54(4):1041-1044
Two new C‐4 norcembranoids sinulochmodins D ( 1 ) and E ( 2 ), along with three known norditerpenoids ( 3–5 ), have been isolated from the organic extract of a Taiwanese soft coral Sinularia lochmodes (Kolonko). The structures of 1 and 2 were determined on the basis of extensive spectroscopic analyses and by comparison of their spectral data with those of related metabolites. 相似文献
100.
Mario J. Cazeca Ramaswamy Nagarajan Min‐Shyan Sheu Max Gow Cecil Comptois Ram W. Sabnis 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(12):1317-1322
A plasma enhanced chemical vapor deposition (PECVD) reactor was used to deposit thin polymeric films with high absorption at 193 nm. The reactor is suitable to deposit uniform and pinhole free thin polymeric films with conformality over 95%. Conformal films with thickness as low as 200 Å have been deposited on silicon, glass, and quartz substrates, as well as silicon oxide, silicon nitrate, and aluminum films. Deposited films had variations in thickness of 3 to 5% over an area of 8 inches in diameter. Thin films deposited on silicon substrates under varying levels of RF power were scanned using the AFM technique. The measurements show increasing surface roughness of the scanned samples as the RF power increases. 相似文献