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981.
This paper introduces the fractional Sobolev spaces on spaces of homogeneous type,includingmetric spaces and fractals. These Sobolev spaces include the well-known Hajfasz-Sobolev spaces as specialmodels.The author establishes varions chaaracterizations of(sharp)maximal functions for these spaces.Asapplications,the author identifies the fractional Sobolev spaces with some Lipscitz-type spaces.Moreover;some embedding theorems are also given.  相似文献   
982.
We provide a new and short proof for Rockafellar's characterization of maximal monotone operators in reflexive Banach spaces based on S. Fitzpatrick's function and a technique used by R. S. Burachik and B. F. Svaiter for proving their result on the representation of a maximal monotone operator by convex functions.

  相似文献   

983.
Palladium(II) dichloride reacts with 1,10‐bis(2‐pyrrolyl)‐2,5,9‐triaza‐1,9‐decadiene to give a [Pd(C15H20N5)]Cl complex in which the ligand is four‐coordinated, leaving one pyrrole group dangling. By using COSY, gHSQC, gHMBC connectivities and NOE experiments it has been concluded that one linkage isomer exists in DMSO solution, in spite of the fact that different sets of N atoms of potentially pentadentate ligand might be involved in coordination, and that the three chelate rings in the complex cation are arranged in a sequence: five‐membered, six‐membered, five‐membered which is different from that (5–5–6) found by x‐ray studies on the related [Ni(C15H20N5)]Cl compound. NMR studies allowed an unambiguous assignment of all 1H and 13C NMR resonances for the complex. Results of x‐ray structural analysis of [Pd(C15H20N5)](CH3COO)H2O supported the five‐membered, six‐membered, five‐membered ring sequence in the [Pd(C15H20N5)]+ complex cation and show an E (trans) orientation of the dangling pyrrole group with respect to the metal center. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
984.
In this paper, we consider approximation to derivatives of a function by using radial basis function interpolation. Most of well-known theories for this problem provide error analysis in terms of the so-called native space, say Cφ. However, if a basis function φ is smooth, the space Cφ is extremely small. Thus, the purpose of this study is to extend this result to functions in the homogenous Sobolev space.  相似文献   
985.
The synthesis of 1,2,3,4-dihydropyrimidinone/thione derivatives was achieved in good to excellent yields using calcium(II) nitrate as catalyst to promote the Biginelli three-component condensation reaction from a diversity of aromatic aldehydes, β-keto compounds and urea or thiourea. The reaction was carried out under solvent-free conditions.  相似文献   
986.
Cardanol-based novolac-type phenolic resins were synthesized with different mole ratios of cardanol-to-formaldehyde, viz., 1:0.6, 1:0.7, and 1:0.8. These novolac resins were epoxidized with molar excess of epichlorohydrin at 120 °C in basic medium. The epoxidized novolac resins were, separately, blended with different weight ratios of carboxyl-terminated polybutadiene liquid rubber ranging between 0-25 wt% with an interval of 5 wt%. All the blends were cured at 150 °C with 40 wt% polyamide. The formation of various products during the curing of blend samples has been studied by Fourier-transform infra-red spectroscopic analysis. The tensile strength and elongation-at-break of the cured samples increased up to 15 wt% in the blend and decreased thereafter. This blend sample was also found to be most thermally stable system. The blend morphology, studied by scanning electron microscopy analysis, was finally correlated with the structural and property changes in the blends.  相似文献   
987.
Segmented block copolymers based on poly(ethylene oxide) (PEO) flexible segments and monodisperse crystallizable bisester tetra‐amide segments were made via a polycondensation reaction. The molecular weight of the PEO segments varied from 600 to 4600 g/mol and a bisester tetra‐amide segment (T6T6T) based on dimethyl terephthalate (T) and hexamethylenediamine (6) was used. The resulting copolymers were melt‐processable and transparent. The crystallinity of the copolymers was investigated by differential scanning calorimetry (DSC) and Fourier Transform infrared (FTIR). The thermal properties were studied by DSC, temperature modulated synchrotron small angle X‐ray scattering (SAXS), and dynamic mechanical analysis (DMA). The elastic properties were evaluated by compression set (CS) test. The crystallinity of the T6T6T segments in the copolymers was high (>84%) and the crystallization fast due to the use of monodisperse tetra‐amide segments. DMA experiments showed that the materials had a low Tg, a broad and almost temperature independent rubbery plateau and a sharp flow temperature. With increasing PEO length both the PEO melting temperature and the PEO crystallinity increased. When the PEO segment length was longer than 2000 g/mol the PEO melting temperature was above room temperature and this resulted in a higher modulus and in higher compression set values at room temperature. The properties of PEO‐T6T6T copolymers were compared with similar poly(propylene oxide) and poly(tetramethylene oxide) copolymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4522–4535, 2007  相似文献   
988.
Dendritic multifunctional macroinitiators having six and 12 TIPNO‐based alkoxyamines, TIPNO‐6 and TIPNO‐12 , were synthesized and used in the living radical polymerization of styrene (St), methyl acrylate (MA), N,N‐dimethylacrylamide (DMAAm), and isoprene (IP). The polymerizations of St initiated with TIPNO‐6 gave 6‐arm star polymers with narrow polydispersities of 1.14–1.18. In the polymerizations of MA initiated with TIPNO‐6 and TIPNO‐12 , the influences of added TIPNO on the polydispersity indexes (PDIs) of the resulting star polymers were first investigated, and this led to the successful formation of poly(MA) star polymers with narrow polydispersities (1.10–1.18). Moreover, the polymerizations of DMAAm and IP from TIPNO‐6 in the presence or absence of TIPNO were briefly investigated. The benzyl ether bonds of the poly(St) and poly(MA) star polymers were cleaved by treating with Me3SiI or Pd/C, and the resulting arm's parts were analyzed with SEC. The PDIs of the resulting arm parts were low (1.19–1.23), and the Mns agreed with the Mn,theor, indicating that the poly(St) and poly(MA) star polymers had well‐controlled arms. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4364–4376, 2007  相似文献   
989.
在齐次Morrey-Herz空间上建立了高阶交换子~$T^{m}_{b,l}$ 和 ~$M^{m}_{b,l}$的有界性,其中~$T^{m}_{b,l}$ 和 ~$M^{m}_{b,l}$ 是由分数次积分算子和分数次极大算子分别与~BMO($R^{n}$)函数生成的高阶交换子.  相似文献   
990.
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