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71.
D.S. Jung S.K. Hong J.S. Cho Y.C. Kang 《Applied Physics A: Materials Science & Processing》2007,89(3):769-774
Fine-sized BaO-ZnO-B2O3-SiO2 (BZBS) glass powders were directly prepared by high temperature spray pyrolysis. The hollow glass powders prepared at low
preparation temperature of 1000 °C had a low density of 2.65 g/cm3. However, the densities of the BZBS powders obtained at preparation temperatures of 1200 and 1400 °C were each 3.92 and 4.13 g/cm3. The mean size of the BZBS glass powders prepared by spray pyrolysis at preparation temperature of 1400 °C was 0.98 μm. The
glass transition temperature (Tg) of the prepared BZBS glass powders was 518.9 °C. The dielectric layers formed from the prepared BZBS glass powders with
a dense structure had a clean surface and a dense inner structure without voids at the firing temperature of 580 °C. The transparencies
of the dielectric layers formed from the prepared BZBS glass powders were higher than 90% within the visible range.
PACS 42.70.Ce; 85.60.Pg; 71.55.Jv 相似文献
72.
A protocol for complete and nondestructive atomic Bell‐state analysis by using inverse engineering is presented. The setups for the Bell‐state analysis contain four atoms trapped in four separated cavities, respectively. The laser pulses designed by inverse engineering help in the manipulation of the transitions of atoms in a robust manner. By using the protocol, the information for distinguishing four Bell states of two information‐carrying atoms is encoded on two auxiliary atoms. Therefore, the four Bell states can be distinguished without being destroyed by detecting the states of the two auxiliary atoms. Moreover, as shown by the numerical simulations, the protocol has high successful probabilities to distinguish four Bell states when decoherence is considered. Thus, the protocol may provide some helpful perspectives for the quantum information tasks based on Bell states. 相似文献
73.
ZnO nanotubes were successfully synthesized by a simple template-free hydrothermal method. X-ray powder diffraction and transmission electron microscopy were used to characterize the as-prepared ZnO nanotubes. The average size of the nanotubes is 200-500 nm in length and 20-30 nm in diameter. In addition, a further investigation of the optimized synthetic conditions has been carried out. 相似文献
74.
The physics behind the spin (polarization)-dependent electromagnetic hot-spot phenomenon is due to the presence of the geometric phase resulting from the optical spin-orbit interaction in the interaction of light with the subwavelength microstructures. Unlike the tiny spin-dependent shift of light associated with the usual spin-Hall effect of light, here we present the distinct polarization-dependent angular shift by employing an array of subwavelength metallic apertures. More importantly, this novel electromagnetic precession is accompanied by the extraordinary optical transmission phenomenon and offers the exciting possibilities for novel applications for subwavelength structured metallic systems. 相似文献
75.
S. Kang Y.-M. Liu T.-Y. Shi 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,63(1):37-42
The energy spectra of H2
+-like impurities confined in
finite spherical quantum dots have been calculated as a function
of the distance between nuclear with different sizes on the basis
of effective-mass approximation by linear variational method.
B-splines have been used as basis functions, which can easily
construct the trial wavefunctions with appropriate boundary and
cusp conditions. The quantitative analyses of the partial wave
weights for ground state and some low lying states have been done. 相似文献
76.
Resonant Reaction in Rb-Cs Vapour Mixture Rb(5P1/2) + Cs(6P3/2) → Cs(8S1/2)+Rb(5S1/2) 总被引:1,自引:0,他引:1 下载免费PDF全文
We experimentally study energy-pooling collision in the Rb-Cs vapour mixture at low densities in a cell. Atoms are excited to Rb(5P1/2) and Cs(6P3/2) states using two single-mode diode lasers. To isolate the heteronuclear contribution in the fluorescence spectrum, a double-modulation technique is adopted. The excited-atom density and spatial distribution are mapped by monitoring the absorption of a counterpropagating single-mode diode laser beam, tuned to Rb(5P1/2 → 7S1/2) and Cs(6Pa/2 → 8S1/2) transitions, respectively, which could be translated parallel to the pump beams. The excited atom densities are combined with the measured fluorescence ratios to determine cross section for the energy-pooling process [i.e. Rb(5P1/2) +Cs (6P3/2) → Cs(8S1/2)+Rb (5S1/2)]. The cross section is 3.79 × 10^-14 cm^2 ± 45%. 相似文献
77.
Lee JS Kim YY Kim JS Kang YJ 《The Journal of the Acoustical Society of America》2008,123(4):2094-2106
Optimal shape design of a two-dimensional poroelastic acoustical foam is formulated as a topology optimization problem. For a poroelastic acoustical system consisting of an air region and a poroelastic foam region, two different physical regions are continuously changed in an iterative design process. To automatically account for the moving interfaces between two regions, we propose a new unified model to analyze the whole poroelastic acoustical foam system with one set of governing equations; Biot's equations are modified with a material property interpolation from a topology optimization method. With the unified analysis model, we carry out two-dimensional optimal shape design of a poroelastic acoustical foam by a gradient-based topology optimization setting. The specific objective is the maximization of the absorption coefficient in low and middle ranges of frequencies with different amounts of a poroelastic material. The performances of the obtained shapes are compared with those of well-known wedge shapes, and the improvement of absorption is physically interpreted. 相似文献
78.
Jin Soo Kim Seul Gi Lee Young Jin Kang Taeg Kyu kwon 《Natural product research》2018,32(10):1216-1219
Kahweol, a compound from Coffea arabica, possesses antioxidant, anti-inflammatory, and antitumour properties. However, an anti-adipogenic effect has not yet been reported. In this study, we have shown that kahweol has an anti-adipogenic effect on 3T3-L1 adipocytes. Kahweol significantly inhibited the differentiation of intracellular lipid accumulation in 3T3-L1 adipocytes, without being cytotoxic. It also downregulated the expression of adipogenesis-related gene, including an adipocytokine, adiponectin. This anti-adipogenic effect stems from an ability to inhibit key adipogenic regulators, including PPARγ and C/EBPα. These results demonstrate that kahweol significantly inhibits the differentiation of 3T3-L1 cells, and suggest that it has potential as a novel anti-obesity treatment. 相似文献
79.
Design of highly active and stable electrocatalyst is a major objective in a fuel cell. The special situation imposed to the electrocatalyst such as one of the most sluggish catalysis of oxygen reduction reaction, inherent structural instability of dispersed nanoparticle, harsh electrochemical conditions of electric potential and nonzero pH aqueous solution requires unique attention in the design. Considering that various attempts have been made for the purpose, high-speed but rigorous formalisms to evaluate the performance of candidates are crucial.This review article briefly introduces recently developed first-principles computational methodologies mainly applied to catalytic activity and electrochemical stability of electrocatalysts in proton exchange membrane fuel cells. Innovative design principles deduced from the outcomes are clearly discussed. 相似文献
80.