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151.
152.
The dendrite growth process of transparent NaBi(WO4)2 with small prandtl and high melting point was studied by using the in-situ observation system. According to the dynamic images and detailed information, there are two kinds of restriction effect on
the dendrite growth, the competition between arms and branches and the convection in the melt. The dendrite growth rate was
time dependent, and the rate of arm growth reached the maximum 5.8 mm/s in the diffusive-advective region and rapidly decreased
in the diffusive-convective region. The growth rate of branch had the same change trends as the arm’s. Based on the EPMA-EDS
data of solidification structure of quenched NaBi(WO4)2 melt, it was found that there were component differences from stoichiometric concentration in the melt near the interface
during the growth process.
Supported by the National Natural Science Foundation of China (Grant No. 50331040) and the Innovation Funds from Shanghai
Institute of Ceramics, Chinese Academy of Sciences (Grant No. SCX0623) 相似文献
153.
The spin coating method was used to assemble polymer (Poly (2,5-dibutoxy-1,4-phenylenevinylene)) (DBO-PPV) into the pores of porous alumina which was prepared by anodization. Four peaks in the photoluminescence (PL) spectra of the composite, with contributions from the DBO-PPV and porous alumina, were found. It was also found that the light emitting from the porous alumina could excite the photoluminescence of DBO-PPV. The nanometer effect of the porous alumina can lead to a blue shift of 90 nm of the PL peaks of DBO-PPV. 相似文献
154.
155.
156.
157.
158.
The possibility of ferromagnetic (FM) and antiferromagnetic (AFM) phase transitions in symmetric nuclear matter is analyzed
within the framework of a Fermi liquid theory with effective Gogny interaction. It is shown that, at some critical density,
nuclear matter with the D1S effective force undergoes a phase transition to the AFM spin state (opposite directions of neutron
and proton spins). The self-consistent equations of spin-polarized nuclear matter with the D1S force have no solutions corresponding
to FM spin ordering (the same direction of neutron and proton spins) and, hence, the FM transition does not appear. The AFM
spin polarization parameter is found for zero and finite temperature. It is shown that the AFM spin polarization parameter
of partially polarized nuclear matter at low enough temperatures increases with temperature. The entropy of the AFM spin state
for some temperature range is larger than the entropy of the normal state. Nevertheless, the free energy of the AFM spin state
is always less than the free energy of the normal state, and the AFM spin-polarized state is preferable for all temperatures
below the critical temperature.
The text was submitted by the authors in English. 相似文献
159.
160.
Seok-Soo Yoon N.A. Buznikov Lan Jin Chong-Oh Kim CheolGi Kim 《Journal of magnetism and magnetic materials》2006
The off-diagonal magnetoimpedance in field-annealed CoFeSiB amorphous ribbons was measured using a pick-up coil wound around the sample. One side of a ribbon was etched in hydrofluoric acid solution during various times in order to change the thickness of the surface crystalline layer appearing after annealing. The asymmetric two-peak field dependence of the off-diagonal impedance was observed for all samples. The evolution of the off-diagonal magnetoimpedance with the change in the ribbon thickness is analyzed. 相似文献