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91.
Preparation of magnesium, lanthanum, and bismuth(III) complexes of 3.6 kDa maltodextrin and some properties of the resulting materials are presented. The metal derivatives contain metals bound to the oxygen atoms of the hydroxyl groups of maltodextrin. Additionally, the metal atoms are coordinated to the hydroxyl groups of the D-glucose units of the macroligand. Such coordination stabilized the metal - oxygen bond against hydrolysis, even in boiling water. The presence of magnesium and lanthanum atoms increased the thermal stability of maltodextrin, whereas bismuth atoms decreased it. 相似文献
92.
93.
We report measurements on Hall-Effect, magnetoresistivity and resistivity for the quasicrystal-system AlCuFe. Data for three different compositions exhibiting electrical resistivities of 4200, 8700 and 9600 cm's, are discussed in terms of quantum corrections in the temperature range 5 to 50 K. It will be shown that the Coulomb contribution of these corrections reacts sensitively to the composition of the quasicrystal.Part of the thesis of R. Haberkern 相似文献
94.
The influence of local and translation invariant memory effects on the critical dynamics of a model undergoing a continous structural phase transition from a disordered (T>T
c
) to an ordered distorted phase (T>T
c
) is studied by mode coupling theory above the critical temperatureT
c
. It is shown that besides the existence of critical slowing-down modes there also exists a central peak as a consequence of correlations of the critical modes, increasing with the critical exponent when approachingT
c
. The dependence of the central peak on the wavevector
, temperatureT and on the spatial dimensiond is investigated. Ford=3 a scenario withlocal long time memory correlations is compared with respect to its temperature and momentum dependence with a model using translation invariant long time memory correlations. 相似文献
95.
Strachan JD Bitter M Ramsey AT Zarnstorff MC Arunasalam V Bell MG Bretz NL Budny R Bush CE Davis SL Dylla HF Efthimion PC Fonck RJ Fredrickson E Furth HP Goldston RJ Grisham LR Grek B Hawryluk RJ Heidbrink WW Hendel HW Hill KW Hsuan H Jaehnig KP Jassby DL Jobes F Johnson DW Johnson LC Kaita R Kampershroer J Knize RJ Kozub T LeBlanc B Levinton F La Marche PH Manos DM Mansfield DK McGuire K McNeill DH Meade DM Medley SS Morris W Mueller D Nieschmidt EB Owens DK Park H Schivell J Schilling G 《Physical review letters》1987,58(10):1004-1007
96.
97.
98.
V.A. Smalyuk O.A. Hurricane J.F. Hansen G. Langstaff D. Martinez H.-S. Park K. Raman B.A. Remington H.F. Robey O. Schilling R. Wallace Y. Elbaz A. Shimony D. Shvarts C. Di Stefano R.P. Drake D. Marion C.M. Krauland C.C. Kuranz 《High Energy Density Physics》2013,9(1):47-51
Kelvin–Helmholtz (KH) turbulent mixing measurements were performed in experiments on the OMEGA Laser Facility [T.R. Boehly et al., Opt. Commun. 133 (1997) 495]. In these experiments, laser-driven shock waves propagated through low-density plastic foam placed on top of a higher-density plastic foil. Behind the shock front, lower-density foam plasma flowed over the higher-density plastic plasma. The interface between the foam and plastic was KH unstable. The experiments were performed with pre-imposed, sinusoidal 2D perturbations, and broadband 3D perturbations due to surface roughness at the interface between the plastic and foam. KH instability growth was measured using X-ray, point-projection radiography. The mixing layer caused by the KH instability with layer width up to ~100 μm was observed at a location ~1 mm behind the shock front. The measured mixing layer width was in good agreement with simulations using a K–L turbulent mixing model in the two-dimensional ARES hydrodynamics code. In the definition of the K–L model K stands for the specific turbulent kinetic (K) energy, and L for the scale length (L) of the turbulence. 相似文献
99.
ATOP dyes. optimization of a multifunctional merocyanine chromophore for high refractive index modulation in photorefractive materials. 总被引:2,自引:0,他引:2
F Würthner S Yao J Schilling R Wortmann M Redi-Abshiro E Mecher F Gallego-Gomez K Meerholz 《Journal of the American Chemical Society》2001,123(12):2810-2824
This paper reports synthesis, characterization and structural optimization of amino-thienyl-dioxocyano-pyridine (ATOP) chromophores toward a multifunctional amorphous material with unprecedented photorefractive performance. The structural (dynamic NMR, XRD) and electronic (UV/vis, electrooptical absorption, Kerr effect measurements) characterization of the ATOP chromophore revealed a cyanine-type pi-conjugated system with an intense and narrow absorption band (epsilon(max) = 140 000 L mol(-)(1) cm(-)(1)), high polarizability anisotropy (deltaalpha(0) = 55 x 10(-)(40) C V(-)(1) m(2)), and a large dipole moment (13 D). This combination of molecular electronic properties is a prerequisite for strong electrooptical response in photorefractive materials with low glass-transition temperature (T(g)). Other important materials-related properties such as compatibility with the photoconducting poly(N-vinylcarbazole) (PVK) host matrix, low melting point, low T(g), and film-forming capabilities were optimized by variation of four different alkyl substituents attached to the ATOP core. A morphologically stable PVK-based composite containing 40 wt % of ATOP-3 showed an excellent photorefractive response characterized by a refractive index modulation of Deltan approximately 0.007 and a gain coefficient of Gamma approximately 180 cm(-)(1) at a moderate electrical field strength of E = 35 V microm(-)(1). Even larger effects were observed with thin amorphous films consisting of the pure glass-forming dye ATOP-4 (T(g) = 16 degrees C) and 1 wt % of the photosensitizer 2,4,7-trinitro-9-fluorenylidene-malononitrile (TNFM). This material showed complete internal diffraction at a field strength of only E = 10 V microm(-)(1) and Deltan reached 0.01 at only E = 22 V microm(-)(1) without addition of any specific photoconductor. 相似文献
100.
B. Ormsby G. Foster T. Learner S. Ritchie M. Schilling 《Journal of Thermal Analysis and Calorimetry》2007,90(2):503-508
After improvements were made to a modified Polymer Labs MkIII DMTA instrument to facilitate repeatable controlled humidity
(RH) experiments using isothermal and thermal scanning conditions, the viscoelastic properties of titanium white pigmented
artists’ acrylic emulsion films were measured in tensile mode. The effects of temperature, relative humidity and accelerated
ageing regimes on two brands of titanium white paints were explored. These paints are highly responsive to changes in temperature
and relative humidity, formulation differences affect properties slightly, and while light ageing had a negligible effect,
thermal ageing resulted in decreased storage modulus and increased film density. 相似文献