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961.
Koo BH Lim KS Ryu DW Lee WR Koh EK Hong CS 《Chemical communications (Cambridge, England)》2012,48(19):2519-2521
A tetranuclear Er(III) compound chelated with N(2)O(2) donors of a tetradentate Schiff base was produced from the self-assembly of the corresponding chemical species. This intriguing cluster shows field-induced slow relaxation of magnetization. 相似文献
962.
The conjunction of porous ZIF-8 with polystyrene spheres is demonstrated to induce the formation of polystyrene@ZIF-8 core-shell structures. A subsequent etching process on polystyrene@ZIF-8 core-shells to remove polystyrene cores results in a unique hollow ZIF-8. 相似文献
963.
We show that the Kerr metric does not exist as a fully rotating black hole solution to modified Hořava–Lifshitz (HL) gravity
with Λ
W
=0 and λ=1. We do this by showing that the Kerr metric does not satisfy the full equations derived from modified HL gravity. 相似文献
964.
Deok‐Yong Cho Hyung‐Suk Jung Il‐Hyuk Yu Won Goo Park Suyeon Cho Useong Kim Se‐Jung Oh Byeong‐Gyu Park Fan‐Hsiu Chang Hong‐Ji Lin Cheol Seong Hwang 《固体物理学:研究快报》2012,6(4):181-183
The unoccupied electronic structures of 5 nm thick high permittivity (k) oxides (HfO2, ZrO2, and Al2O3) and SiO2 films on Ge substrates were examined using O K‐edge X‐ray absorption spectroscopy. Comparative studies with those on Si substrates showed contrasts in the conduction bands, which should be due to the formation of interface states. In the Al2O3 and SiO2 films, GeO2 layers are formed at the interface and they suppress in part the formation of detrimental germanate phases. In contrast, in the HfO2 and ZrO2 films, no signature of the Ge‐oxide phase is observed but some germanate phases are expected to prevail, suggesting a degradation of the gate oxide characteristics. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
965.
We consider a discrete-time single server N -policy GI/Geo/1 queueing system. The server stops servicing whenever the system becomes empty, and resumes its service as soon as the number of waiting customers in the queue reaches N. Using an embedded Markov chain and a trial solution approach, the stationary queue length distribution at arrival epochs is obtained. Furthermore, we obtain the stationary queue length distribution at arbitrary epochs by using the preceding result and a semi-Markov process. The sojourn time distribution is also presented. 相似文献
966.
Ki Won Lim Jin Yong Jun Byeong Jun Lee 《Journal of Thermal Analysis and Calorimetry》2012,109(1):487-494
The calorific value is defined as the amount of heat which would be released by the complete combustion in air, in such a way that the pressure remains constant, all the combustion products except water are gaseous states and all the products returned to the temperature of the reactants. Recently, the mixed fuel like LPG, LNG, hythane, etc., become more popular. But the composition of these fuels changes with time and place where it was produced, which give direct impacts on the calorific value and performance of the heating apparatus. Therefore, the accurate measurements of the calorific value become an issue in the refinery industries and the national standardization fields. So, flame calorimeter was manufactured and characterized to measure calorific value of the gaseous fuel in the flow situations. Electric substitution method initiated by Alexandrov was adopted. Peltier elements were used to emit the heat supplied by a heater and a flame to the cooling water. Freon-11 was used as a heat carrier. To get the accurate calorific value by the experiments conducting in the normal laboratory conditions, correction methods were proposed to count variations in the experimental conditions such as temperatures, electric powers, etc. It was found out that the corrected calorific value of pure methane had 0.36% relative deviation to the standard value. 相似文献
967.
Xiao L Ha JW Wei L Wang G Fang N 《Angewandte Chemie (International ed. in English)》2012,51(31):7734-7738
Keeping track: By combining differential interference contrast (DIC) image pattern recognition with DIC polarization anisotropy, the exact full three-dimensional angular information of individual tilted gold nanorods positioned in the focal plane of the objective lens can be readily determined. The angular rotational modes and kinetics of individual in-focus gold nanorods can thus be resolved dynamically. 相似文献
968.
Wee KR Han WS Cho DW Kwon S Pac C Kang SO 《Angewandte Chemie (International ed. in English)》2012,51(11):2677-2680
A bright combination: a new type of donor-acceptor dyad, carbazolylaryl-substituted ortho-carboranes, which are conveniently prepared from the corresponding acetylenes and decaborane pathways, showed unique excited-state behavior associated with electron transfer unlike the meta- and para-counterparts. 相似文献
969.
Vanecht E Binnemans K Patskovsky S Meunier M Seo JW Stappers L Fransaer J 《Physical chemistry chemical physics : PCCP》2012,14(16):5662-5671
The stability of gold nanoparticles synthesised by sputter deposition has been studied in situ in 1-butyl-3-methylimidazolium ionic liquids with bis(trifluoromethylsulfonyl)imide, tetrafluoroborate, hexafluorophosphate and dicyanamide anions with UV-VIS absorption spectroscopy and transmission electron microscopy. Besides the growth of the gold nanoparticles, two other processes were observed after sputtering, namely aggregation and sedimentation of these nanoparticles. To model the absorption spectra of the sputtered gold nanoparticles, generalized multiparticle Mie calculations were performed. These theoretical calculations confirm the increase in absorbance at longer wavelength for larger aggregates and are in agreement with the experimental observations. It was found that the kinetics of aggregation and sedimentation scale with the viscosity of the ionic liquid. Small amounts of water were found to have a large detrimental influence on the stability of the colloidal suspensions of the gold nanoparticles in ionic liquids. From the large discrepancy between the theoretical and the experimentally observed stability of the NPs, it was concluded that structural forces stabilize the gold nanoparticles. This was also borne out by AFM measurements. 相似文献
970.
Kim BH Hong WG Yu HY Han YK Lee SM Chang SJ Moon HR Jun Y Kim HJ 《Physical chemistry chemical physics : PCCP》2012,14(4):1480-1484
We have obtained high pressure H(2) isotherms with respect to the interlayer distance of multilayered graphene oxide (GO) modulated by thermal annealing. The maximum storage capacity is 4.8 (0.5) wt% at 77 K (298 K) and at 9.0 MPa pressure. We found the optimum GO interlayer distance for maximum H(2) uptake at 6.5 ?, similar to the predicted distances from first-principles calculations for graphite materials. Our results reveal that multilayered GO can be a practical material of choice to allow the use of graphene as a hydrogen storage material, provided that only small amounts of O and OH functional groups exist as spacers on GO sheets. 相似文献