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71.
72.
Hyunwoo Choi Seungbum Hong Yunseok Kim Myungjun Kim Tae‐Hyun Sung Hyunjung Shin Kwangsoo No 《固体物理学:研究快报》2011,5(2):59-61
PbTiO3 (PTO) nanotubes (NTs) were synthesized at various temperatures by gas phase reaction between PbO gas and anatase TiO2 NTs and characterized by piezoresponse force microscopy (PFM). PTO ferroelectric phase was synthesized at as low as 400 °C as evidenced by PFM domain images and piezoresponse hysteresis loop measurement. Furthermore, the PTO NTs fabricated at above 500 °C underwent mechanical fracture through development of nanocracks due to grain growth, leading to ferroelectric domains with larger size and lower aspect ratio. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
73.
In this paper, we construct a new Roper-Suffridge extension operator Φr n,β1,,βn(f)(z) = F(z) = ((rf(z1/r)/z1)β1z1,(rf(z1/r)/z1)β2z2,...,(rf(z1/r)/z1)βnzn)',where f is a normalized locally biholomorphic function on the unit disc D, r = sup{|z1| : z =(z1, ···, zn) ∈Ω}, β1∈ [0, 1], 0 ≤βk≤β1, k = 2, ···, n, then we prove it can preserve the property of spirallikeness of type β, almost starlikeness of order α and starlikeness of orderα on bounded complete Reinhardt domain Ω, respectively. 相似文献
74.
We show that the equality m1(f(x))=m2(g(x)) for x in a neighborhood of a point a remains valid for all x provided that f and g are open holomorphic maps, f(a)=g(a)=0 and m1,m2 are Minkowski functionals of bounded balanced domains. Moreover, a polynomial relation between f and g is obtained. 相似文献
75.
76.
Amphiphilic urethane acryale hydrogels containing ionic groups (dimethylolpropionic acid) were prepared by varying the molecular
weight of the soft segment (polyether type) and the type of diisocyanate, and their mechanical properties were examined. They
showed heterophasic gel structure composed of ionic hard domains induced by aggregation of the ionic groups and polyether
soft domains comprising the urethane acrylate network. This heterophasic structure could be confirmed by dynamic mechanical
analysis (DMA) and by wide-angle X-ray scattering analysis (WAXS); the crystallinity detected by WAXS and the transition peak
of the ionic hard domains detected by DMA strongly suggested that there were ionic aggregates. These ionic aggregates acted
as reinforcing fillers in the network, which eventually enhanced the tensile strength of the hydrogels. Above all, the tensile
properties of the hydrogels were of interest in that the trends of the stress-strain curves were consistent with the rubbery
ones. It is believed that the higher purity of the polyether soft domains resulted from the heterophasic gel structure imparting
further elastomeric properties on the network.
Received: 31 July 1998 Accepted in revised form: 15 October 1998 相似文献
77.
78.
Jun Geng 《Journal of Functional Analysis》2010,259(8):2147-2164
We show that the Neumann problem for Laplace's equation in a convex domain Ω with boundary data in Lp(∂Ω) is uniquely solvable for 1<p<∞. As a consequence, we obtain the Helmholtz decomposition of vector fields in Lp(Ω,Rd). 相似文献
79.
We study the contractibility of the efficient solution set of strictly quasiconcave vector maximization problems on (possibly) noncompact feasible domains. It is proved that the efficient solution set is contractible if at least one of the objective functions is strongly quasiconcave and any intersection of level sets of the objective functions is a compact (possibly empty) set. This theorem generalizes the main result of Benoist (Ref.1), which was established for problems on compact feasible domains.The authors thank Dr. T. D. Phuong, Dr. T. X. D. Ha, and the referees for helpful comments and suggestions. 相似文献
80.
Miglena Koleva Lubin Vulkov 《Numerical Methods for Partial Differential Equations》2007,23(2):379-399
The numerical solution of the heat equation in unbounded domains (for a 1D problem‐semi‐infinite line and for a 2D one semi‐infinite strip) is considered. The artificial boundaries are introduced and the exact artificial boundary conditions are derived. The original problems are transformed into problems on finite domains. The space semi‐discretization by finite element method and the full approximation by the implicit‐explicit Euler's method are presented. The solvability of the full discretization schemes is analyzed. Computational examples demonstrate the accuracy and the efficiency of the algorithms. Also, the behavior of blowing up solutions is examined numerically. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 379–399, 2007 相似文献