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Limiting Properties (limiting + property)
Kinds of Limiting Properties Selected AbstractsA Graphene Hybrid Material Covalently Functionalized with Porphyrin: Synthesis and Optical Limiting PropertyADVANCED MATERIALS, Issue 12 2009Yanfei Xu An organic solution-processable functionalized graphene (SPFGraphene) hybrid material with porphyrins is reported for the first time. FTIR, UV-vis absorption, and TEM studies confirm the covalent functionalization of the graphene. A superior optical limiting effect, better than the benchmark optical limiting material C60 and the control sample, is observed. [source] Strong Optical Limiting of Soluble Axially Substituted Gallium and Indium Phthalocyanines,ADVANCED MATERIALS, Issue 11 2003Y. Chen Optical limiting in In- and Ga-phthalocyanines exhibits a range of saturation densities and absorption cross-section ratios. Substitution of the p -trifluoromethylphenyl group at the central metal in tBu4PcGaCl and tBu4PcInCl reduces the saturation energy density by a factor of >3. Tailorable optical limiting properties are shown in the Figure, which plots the nonlinear absorption coefficient as a function of intensity for the five compounds studied. [source] Stilbene-containing polyactylenes: Molecular design, synthesis, and relationship between molecular structure and NLO propertiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 13 2008Xinyan Su Abstract Polyacetylenes (P1,P4) containing different stilbene groups, [(CHC) PhCHCHPhR]n(ROCmH2m+1 (m = 4 (P1), 10 (P2), 16 (P3)), or NO2 (P4)) were designed and synthesized, respectively, using [Rh(nbd)Cl]2 as a catalyst. Their structures and properties were characterized and evaluated by FTIR, 1H-NMR, 13C-NMR, GPC, and UV, PL, respectively. The optical limiting and nonlinear optical properties were investigated by using a frequency doubled, Q-switched, mode-locked Continuum ns/ps Nd:YAG laser system and their optical limiting mechanism was discussed. It is surprising to see that the stilbene pendants endow the polyacetylenes with a high thermal stability (Td , 270 °C), novel optical limiting properties and large third-order nonlinear optical susceptibilities (up to 4.61 × 10,10 esu). The optical limiting mechanism is mainly originated from reverse saturable absorption of molecules. In addition, it is found that the polymer with electron accepted NO2 moiety exhibits better optical properties than that with electron donated alkoxy group because of larger , electron delocalization and dipolar effect. The strong interaction between stilbene pendants and the polyene main chain significantly results in red-shift of fluorescence emitting peak. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4529,4541, 2008 [source] Preparation and properties of polyethoxysilsesquioxane-C60 hybridsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2007Takahiro Gunji Abstract Free-standing films of C60 -polyethoxysiloxane hybrids were prepared, and their optical limiting properties were evaluated. Triethoxysilylated C60, with a formula of H3C60[Si(OEt)3]3, was synthesized by the hydrolysilylation of C60 with triethoxysilane in the presence of platinum catalyst. C60 -polyethoxysiloxanes were prepared by a cohydrolytic polycondensation of triethoxysilylated C60 with tetraethoxysilane in a molar ratio of Si/C60 = 10,1000 under nitrogen flow. The molecular weight of C60 -polyethoxysiloxane increased with a decrease of Si/C60. Transparent and flexible free-standing films were prepared by aging an ethanol solution of C60 -polyethoxysiloxane at 80 °C for 6,8 days. The mechanical strength and Young's modulus increased with a decrease in Si/C60. These free-standing films showed an optical limiting property, for which the threshold value decreased from 1163 mJ/cm2 (Si/C60 = 1000) to 130 mJ/cm2 (Si/C60 = 10) with a decrease of Si/C60. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3273,3279, 2007 [source] Random dyadic tilings of the unit squareRANDOM STRUCTURES AND ALGORITHMS, Issue 3-4 2002Svante Janson A "dyadic rectangle" is a set of the form R = [a2,s, (a + 1)2,s] × [b2,t, (b + 1)2,t], where s and t are nonnegative integers. A dyadic tiling is a tiling of the unit square with dyadic rectangles. In this paper we study n -tilings, which consist of 2n nonoverlapping dyadic rectangles, each of area 2,n, whose union is the unit square. We discuss some of the underlying combinatorial structures, provide some efficient methods for uniformly sampling from the set of n -tilings, and study some limiting properties of random tilings. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 21: 225,251, 2002 [source] Preparation and properties of polyethoxysilsesquioxane-C60 hybridsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2007Takahiro Gunji Abstract Free-standing films of C60 -polyethoxysiloxane hybrids were prepared, and their optical limiting properties were evaluated. Triethoxysilylated C60, with a formula of H3C60[Si(OEt)3]3, was synthesized by the hydrolysilylation of C60 with triethoxysilane in the presence of platinum catalyst. C60 -polyethoxysiloxanes were prepared by a cohydrolytic polycondensation of triethoxysilylated C60 with tetraethoxysilane in a molar ratio of Si/C60 = 10,1000 under nitrogen flow. The molecular weight of C60 -polyethoxysiloxane increased with a decrease of Si/C60. Transparent and flexible free-standing films were prepared by aging an ethanol solution of C60 -polyethoxysiloxane at 80 °C for 6,8 days. The mechanical strength and Young's modulus increased with a decrease in Si/C60. These free-standing films showed an optical limiting property, for which the threshold value decreased from 1163 mJ/cm2 (Si/C60 = 1000) to 130 mJ/cm2 (Si/C60 = 10) with a decrease of Si/C60. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3273,3279, 2007 [source] | ||||||||||