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101.
We study global symmetry breaking in the 2D system of scalar nonconserved order parameter following a quench to zero temperature. We show that the instant of time when the symmetry is broken and the final morphology is chosen corresponds to the saturation of the order parameter inside the domains. There are three possible final morphologies: the positive and negative order parameter final morphology, and the state of the coexisting positive and negative order parameter subsystems with a flat interface between them. We find also that each type of the final morphology constitutes about 1/3 of all cases, what agrees with the results obtained recently by Spirin et al. [Phys. Rev. E 65, 016119 (2001)]. Our results are pertinent for the two dimensional systems, but we suspect that there is also a way to apply similar arguments for the three dimensional ones. 相似文献
102.
Ying?HeEmail author Wenbin?Sang Jun’an?Wang Ruofeng?Wu Jiahua?Min 《Journal of nanoparticle research》2005,7(2-3):307-311
The growth of the oriented zinc oxide (ZnO) nanorods on silicon substrates based on a simple novel chemical transformation and thermal hydrolysis by using polyvinyl alcohol (PVA) as self-assembling complex polymer was introduced in this paper. All the polymers were removed after chemical oxidation and only the carbonized grid backbones remained that confines the ZnO nanorod’s diameter and enhance the absorption and diffusion of ZnO at the tips of the nanorods during growth. The ZnO nanorods are investigated by FTIR, XRD and FE-SEM. The results indicated that these nanorods have fine hexagonal wurtzite crystal structure and their diameter varies from 20 to 90 nm and the length up to about 1 μm. A polymer-localized ZnO growth model is proposed, which well explains the growth behavior of ZnO nanorods.This revised version was published online in August 2005 with a corrected issue number. 相似文献
103.
Kodibagkar VD Browning CD Tang X Wu Y Bowman RC Conradi MS 《Solid state nuclear magnetic resonance》2003,24(4):254-262
Powders of three hexagonal metal-hydrides or -deuterides are found to align in 4.4–8.3 T magnetic fields used for NMR. The field-alignment is unexpected, since all three systems have very small susceptibilities, as demonstrated by sharp NMR lines. The extent of alignment runs from nearly complete to barely detectable in ZrBe2(H,D)x, LuD3, and YD3, respectively. The preferred alignment direction in ZrBe2(H,D)x is with the crystallites’ c-axis perpendicular to B, while the c-axis and B tend to be parallel in LuD3 and YD3. The susceptibilities χ|| and χ are determined from bulk magnetization measurements in aligned ZrBe2H1.4 powder. The alignment must be considered for proper analysis of NMR spectra in these and related materials. 相似文献
104.
The purpose of this paper is to show certain links between univariate interpolation by algebraic polynomials and the representation of polyharmonic functions. This allows us to construct cubature formulae for multivariate functions having highest order of precision with respect to the class of polyharmonic functions. We obtain a Gauss type cubature formula that uses values of linear functionals (integrals over hyperspheres) and is exact for all -harmonic functions, and consequently, for all algebraic polynomials of variables of degree .
105.
Xian Zhou Xiaoqian Sun Jinglong Wang 《Annals of the Institute of Statistical Mathematics》2001,53(4):760-768
Let X
1, , X
n
(n > p) be a random sample from multivariate normal distribution N
p
(, ), where R
p
and is a positive definite matrix, both and being unknown. We consider the problem of estimating the precision matrix –1. In this paper it is shown that for the entropy loss, the best lower-triangular affine equivariant minimax estimator of –1 is inadmissible and an improved estimator is explicitly constructed. Note that our improved estimator is obtained from the class of lower-triangular scale equivariant estimators. 相似文献
106.
分别在苏打石灰玻璃、Mo箔、无择优取向的Mo薄膜以及(110)择优取向的Mo薄膜四种不同衬底上,采用共蒸发工艺沉积约2 μm厚的Cu(In,Ga)Se2薄膜,用X射线衍射仪测量薄膜的织构,研究衬底对Cu(In,Ga)Se2薄膜织构的影响.在以上四种衬底上沉积的Cu(In,Ga)Se2薄膜的(112)衍射峰强度依次逐渐减弱,(220/204)衍射峰从无到有且强度逐渐增强.在苏打石灰玻璃和Mo箔衬底上的Cu(In,Ga)Se2关键词:
择优取向
Cu(In
2薄膜')" href="#">Ga)Se2薄膜
太阳电池 相似文献
107.
108.
S. Heinemeyer 《Pramana》2007,69(5):947-951
Electroweak precision measurements can provide indirect information about the possible scale of supersymmetry already at the
present level of accuracy. We review present day sensitivities of precision data in mSUGRA-type models with the gravitino
as the lightest supersymmetric particle (LSP). The χ
2 fit is based on M
W
, sin2
θ
eff, (g−2)
μ
, BR(b → sγ) and the lightest MSSM Higgs boson mass, M
h
. We find indications for relatively light soft supersymmetry-breaking masses, offering good prospects for the LHC and the
ILC, and in some cases also for the Tevatron.
相似文献
109.
110.
Alexander Čeklovský Juraj Bujdák Adriana Czímerová Nobuo Iyi 《Central European Journal of Physics》2007,5(2):236-243
Tetracationic porphyrin dyes TMPyP and ZnPyP were intercalated into hydrophobized layered silicate films of three smectites.
The smectites represented the layered silicate specimens of high (Fluorohectorite, Corning; FHT), medium (Kunipia F montmorillonite;
KF) and low layer charge (Laponite, Laporte; LAP). The molecular orientations of the dye cations were studied by means of
linearly-polarized ultraviolet-visible (UV-VIS) spectroscopy. The spectral analysis and consequent calculations of tilting
angles of the transition moments at the wavelengths of Soret band transitions were in the range of 25°-35°. The determined
angles indicated molecular orientation of the dye cations being almost parallel to the surface of the silicates. Slightly
higher values (above 35°), determined for a FHT film, indicated either a slightly tilted orientation of the dye cations or
the change of molecular comformation after the intercalation of the dye.
Presented at 5-th International Conference Solid State Surfaces and Interfaces, November 19–24, 2006, Smolenice Castle, Slovakia 相似文献