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Diffraction Spectra (diffraction + spectrum)
Kinds of Diffraction Spectra Selected AbstractsPreparation, physicochemical and third order nonlinear optical properties of bis(tetrabutylammonium)bis(2-thioxo-1,3-dithiole-4,5-dithiolato)mercurate(II)CRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2009X. Q. Wang Abstract Bis(tetrabutylammonium)bis(2-thioxo-1,3-dithiole-4,5-dithiolato)mercurate(II) was prepared and characterized by elemental analyses, electronic absorption, infrared and X-ray powder diffraction spectroscopy. The specific heat of the crystal was measured to be 1878.2 J.mol,1K,1 at 300 K. The thermal decomposition process was investigated by means of thermogravimetric analysis and differential thermal analysis measurements in air together with infrared and X-ray powder diffraction spectra. The third-order nonlinear optical properties at 800 nm were measured by femtosecond optical Kerr gate technique by using CS2 as reference. The third-order optical susceptibility of its acetone solution at the concentration of 9.27 × 10,4 M was obtained to be 2.53 × 10,14 esu. The second-order hyperpolarizability was estimated to be 1.7 × 10,32 esu and the response time was about 226 fs. The third order nonlinear optical properties at 532 nm were investigated by using the Z-scan technique with 20 ps. It exhibited self-focusing effect and saturable absorption. The second molecular hyperpolarizability was estimated to be 8.4 × 10,32 esu. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Chemical, Mechanical, and Antibacterial Properties of Silver Nanocluster,Silica Composite Coatings Obtained by Sputtering,ADVANCED ENGINEERING MATERIALS, Issue 7 2010Monica Ferraris Abstract Silver nanocluster,silica matrix composite coatings have been deposited by radio frequency (RF) co-sputtering on silica substrates. Field emission scanning electron microscopy and X-ray diffraction spectra of the as deposited and heated samples (150,600,°C) revealed the presence of metal silver nanoclusters, their size depending on the heating treatment. The antibacterial activity of the as deposited and heated samples has been measured in accordance to National Committee for Clinical Laboratory Standards, and it has been demonstrated on samples heated up to 450,°C in contact mode and for samples heated at 600,°C in a liquid environment. Their antibacterial activity was still present after gamma ray and ethylene oxide gas (EtO) sterilization of the samples. Silver leaching tests on the as deposited and heated samples has been measured by graphite furnace atomic absorption spectrometer, revealing an amount ranging from 0.1 to 0.9,µg mm,2, over 28 days. Tape resistance (ASTM D3359-97) and scratch resistance tests have been done on each sample revealing a good adhesion of the coatings on silica. [source] Novel interpenetrating networks with shape-memory propertiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2007Shifeng Zhang Abstract Novel polyesterurethane/poly(ethylene glycol) dimethacrylate (PEGDMA) interpenetrating networks (IPNs) with good shape-memory properties were synthesized using solvent casting method. The star-shaped oligo[(rac -lactide)- co -glycolide] was coupled with isophorone diisocyanate to form a polyesterurethane network (PULG), and PEGDMA was photopolymerized to form another polyetheracrylate network. IPNs were transparent and gel content exceeded 92%. The values of strain fixity rate and strain recovery rate were above 93%. PULG and PEGDMA networks in IPNs were amorphous and did not show any characteristic diffraction peaks in X-ray diffraction spectra. Only one glass transition temperature (Tg) of the IPNs between Tg of PEGDMA and PULG was observed, which was proportional to PEGDMA content. PULG and PEGDMA networks were miscible when PEGDMA content was below 50 wt %. The hydrophilicity, transition temperatures, and mechanical properties of IPNs could be conveniently adjusted through variation of network compositions to match the promising potential clinical or medical applications. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 768,775, 2007 [source] Optical, electrical and structural characterization of CuInSe2 thin filmsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 9 2005C. Calderón The present issue of physica status solidi (b) comprises papers presented at the XVII Latin American Symposium on Solid State Physics (SLAFES 2004) in Havana, Cuba, 6,9 December 2004. Further papers from this conference are published in phys. stat. sol. (c) 2, No. 10 (2005). The cover picture refers to the article [1] on polycrystalline CuInSe2 films by Clara Calderón et al. and shows the crystal structure of CuInSe2 (right) and that of the In-rich phase CuIn3Se5 (left) which were used for the simulation and analysis of the X-ray diffraction spectra. Clara Lilia Calderón Triana is teacher at the Solar Cells Laboratory of Universidad Nacional de Colombia in Bogotá where she has been working on solar cells and semiconductor materials since 1995. In particular, she is fabricating thin film solar cells based on CuInSe2 and Cu(In,Ga)Se2. At SLAFES 2004, Clara Calderón received the physica status solidi Young Researcher Award for her second presentation entitled "Study of electrical transport properties of ZnO thin films used as front contact of solar cells" [2] which is published as Editor's Choice of this issue. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Study on the excimer laser annealed amorphous hydrogenated silicon carbon films deposited by PECVDPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3-4 2010G. Ambrosone Abstract Hydrogenated amorphous silicon carbon films of different carbon content were deposited by plasma enhanced chemical vapour deposition at low substrate temperature (200 °C) and were subjected to excimer laser annealing. X-ray diffraction spectra and field emission scanning electron microscopy images demonstrate that carbon content plays an important role in facilitating the crystallization process induced by the excimer laser treatment (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Interfacial interactions and performance of polyamide 6/modified attapulgite clay nanocompositesPOLYMER COMPOSITES, Issue 2 2009Bingli Pan Attapulgite (AT) clay was firstly treated with sodium polyacrylate (PAS), then polyamide 6 (PA6)/AT nanocomposites were prepared by simple melt compounding. Transmission electron microscope (TEM) and Fourier transform infrared spectrometry (FT-IR) of treated AT confirm the success of purifying and surface modification of the original AT by PAS. X-ray diffraction spectra for the nanocomposites show that the microstructure of AT in PA6 matrix is almost unchanged. It indicates that a strong interfacial adhesion exists between AT and PA6 matrix through analyzing fracture surfaces of the nanocomposites, the variation of glass transition temperature (Tg) obtained by dynamic mechanical analysis, and interfacial interaction factors; field emission scanning electron microscopy on the fracture surfaces of the nanocomposites shows that a uniform dispersion of AT is obtained. The above two aspects conform to the improvement of mechanical and thermal properties of the nanocomposites. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source] Multiresolution of quasicrystal diffraction spectraACTA CRYSTALLOGRAPHICA SECTION A, Issue 6 2009Avi Elkharrat A method for analyzing and classifying two-dimensional pure point diffraction spectra (i.e. a set of Bragg peaks) of certain self-similar structures with scaling factor , > 1, such as quasicrystals, is presented. The two-dimensional pure point diffraction spectrum , is viewed as a point set in the complex plane in which each point is assigned a positive number, its Bragg intensity. Then, by using a nested sequence of self-similar subsets called ,-lattices, we implement a multiresolution analysis of the spectrum ,. This analysis yields a partition of , simultaneously in geometry, in scale and in intensity (the `fingerprint' of the spectrum, not of the diffracting structure itself). The method is tested through numerical explorations of pure point diffraction spectra of various mathematical structures and also with the diffraction pattern of a realistic model of a quasicrystal. [source] Vapor-induced crystallization behavior of bisphenol-A polycarbonatePOLYMER ENGINEERING & SCIENCE, Issue 6 2006Zhongyong Fan The effects of exposure time and vapor pressure on the crystallization behaviors of bisphenol-A polycarbonate (BAPC) films were investigated at 25°C by using differential scanning calorimetry (DSC). Double melting peaks were observed for various BAPC samples after vapor-induced crystallization. The low temperature melting peak shifted to higher temperature and became sharper with increasing exposure time, and could be assigned to defective crystals with smaller crystal size. Crystallinity and average crystal dimension normal to (020) were calculated from wide-angle X-ray diffraction spectra. A good agreement was obtained between crystallinity values obtained from WAXD and those from DSC. The morphology of crystallized samples after various exposure time periods was examined by means of polarized optical microscopy. Nucleation occurred at the initial stage of vapor-induced crystallization. Poor crystals become perfect through segment reorganization with increasing exposure time, and spherulites' growth was observed. The average diameter of spherulites increased from 2 ,m for 1 h, to 7 and 16 ,m after 3 and 56 h, respectively. POLYM. ENG. SCI., 46:729,734, 2006. © 2006 Society of Plastics Engineers [source] Inferring planar disorder in close-packed structures via,-machine spectral reconstruction theory: structure and intrinsic computation in zinc sulfideACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2007D. P. Varn We apply ,-machine spectral reconstruction theory to analyze structure and disorder in four previously published zinc sulfide diffraction spectra and contrast the results with the most common alternative theory, the fault model. In each case we find that the reconstructed ,-machine provides a more comprehensive and detailed understanding of the stacking structure, often detecting stacking structures not previously found. Using the ,-machines reconstructed for each spectrum, we calculate a number of physical parameters , such as configurational energies, configurational entropies and hexagonality , and several quantities , including statistical complexity and excess entropy , that describe the intrinsic computational properties of the stacking structures. [source] Alumino-organic derivatives of some dioximesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 10 2002Nicolae Voiculescu Abstract The alumino-organic combinations of the dioximes (DOxH2) examined in this paper result from the substitution of the hydrogen bonds of oximes by alumino-organic groups. Relative to the same alumino-organic derivatives, diphenylglyoxime (DPGH2) behaves similarly to dimethylglyoxime (DMGH2). The chemical reactivity of DPGH2 towards these alumino-organic compounds is, however, less than in the case of DMGH2. An exception is the monomer state of (DPG)[Al(i-C4H9)2]2 in benzene solution. The behavior relative to amines of alkyl derivatives is similar to that found in coordinated oximes. In contrast, phenylaluminum derivatives of DMGH2 and DPGH2 are not soluble in amines. All compounds reported in this paper were separated from the reaction mixture as colored powders and were characterized by chemical analyses, IR spectroscopy, X-ray diffraction spectra and 1H NMR. Finally, a comparison between the reactivity of free and coordinated dioximes is briefly considered. It is hoped that such comparisons will throw light on the problems associated with the reactivity of free and coordinated oxides versus alumino-organic compounds. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||||||||