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81.
We present a direct measurement of self-diffusion of a single-component glass-forming liquid at the glass transition temperature. Forward recoil spectrometry is used to measure the concentration profiles of deuterio and protio 1,3-bis-(1-naphthyl)-5-(2-naphthyl)benzene (TNB) following annealing-induced diffusion in a vapor-deposited bilayer. These experiments extend the range of measured diffusion coefficients in TNB by 6 orders of magnitude. The results indicate a decoupling of translational diffusion coefficients from viscosity or rotation. At T(g), D(T) is 400 times larger than expected from the Stokes-Einstein equation. 相似文献
82.
A nearlattice S is a meet semilattice together with the property that any two elements possessing a common upper bound have a supremum. Here the authors have introduced the notion of sectionally semicomplemented distributive nearlattices and given several characterizations of them. The skeleton SCon(S) of Con(S), the congruence lattice, consists of all those nearlattice congruences which are the pseudocomplements of members of Con(S). The relationship between skeletal congruences and kernel of skeletal congruences leads to numerous characterizations of sectionally semicomplemented distributive nearlattices and semiboolean algebras. For example we prove, for a distributive nearlattice S with 0, the following conditions are equivalent:
AMS Subject Classifications (1991): 06A12, 06A99, 06B10. 相似文献
(i) | S is sectionally semicomplemented |
(ii) | The map Θ Θ ̸ker Θ of SCon(S) onto KSCon(S) is one-to-one. |
(iii) | The map Θ Θ ̸ker Θ of SCon(S) onto KSCon(S) preserves finite joins. |
(iv) | The map Θ Θ ker ̸Θ is a lattice isomorphism of SCon(S) onto KSCon(S), whose inverse is the map J ̸ Θ(J)**. |
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84.
The basic characteristics of fibers that are appropriate for surgical use in the infrared are reviewed. New fiber materials, such as sapphire, fluorozirconate and chalcogenide glasses, and polycrystalline fibers are discussed as well as their applicability for surgical procedures. 相似文献
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87.
A magnetized Iron CALorimeter (ICAL) detector at the India-based neutrino observatory (INO) is used to study neutrino oscillation sensitivity using atmospheric muon neutrino source. The ICAL detector will be able to detect muon tracks and hadron showers produced by neutrino interactions with the iron target. We have performed precision measurement analysis for the atmospheric neutrino oscillation parameters with the muon neutrino events, generated by Monte Carlo NUANCE event generator. A marginalized χ2 analysis based on reconstructed neutrino energy and muon zenith angle binning scheme has been performed to determine the sensitivity for the atmospheric neutrino mixing parameters, \(\sin ^{2}\theta _{23}\) and \(| {\Delta } m^{2}_{23}|\). 相似文献
88.
Variable temperature 2H-NMR T1 experiments were performed on backbone deuterated atactic polystyrene in four solvents at two Larmor frequencies. Temperature-frequency superposition, which is consistent with experimental results for many other polymers, cannot describe our data. This indicates that the shape of the correlation function for C-D vector reorientation is temperature dependent. A modified log χ2 distribution, of relaxation times, i.e., a delta function plus a log χ2 distribution, was used to fit the experimental data. These fits are consistent with literature 13C T1 and NOE data. As polystyrene local dynamics slow down by a factor of 5, the FWHM of the log χ2 distribution increases from 0.8 to 1.1 decades. Solvent identity does not play a major role in determining the shape of the correlation function. The fraction of the correlation function decay caused by librational motion was determined to be 0.28. The quantity was compared for series of polymers and found to correlate with the size of the side group. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35 : 1241–1250, 1997 相似文献
89.
Reorientation times ťc for two probes in several amorphous polymers near the glass transition temperature Tg are reported. Tg for these polymers ranges from 205 to 459 K. Probe reorientation was measured in the time window from 10−2 to 104 s with a recently developed photobleaching method. ťc for a given probe at the Tgs of the different polymers varies more than three decades. Viscoelastic relaxation times characteristic of the Rouse modes of the matrix polymers are closely related to probe rotation times and thus also not constant at Tg. The characteristic length scale of motions responsible for the glass transition varies significantly for the three polymers studied. Preliminary physical aging results indicate that probe reorientation in polystyrene ages slightly faster than the volume. 相似文献
90.
Thuy-Kieu Truong Ji Hyun Park MD Asiqur Rahman Martin Urbanski Eun Sung Kim Giusy Scalia Dongseok Suh 《Current Applied Physics》2019,19(2):162-167
The use of a highly aligned carbon nanotube (CNT) sheet as a multifunctional constituent for liquid crystal (LC) displays and electro-optic LC applications is assessed. The CNT sheet can perform a dual function: one is an alignment layer for LCs, replacing the commonly used rubbed polyimide film, and the other is a transparent conductive layer, taking the place of indium tin oxide. The hydrophobic treatment improved the adhesion quality between aligned CNT bundles and the glass substrate, which helps to preserve the inherently aligned nanogroove morphology of transparent CNT sheets. The test LC display cells, comprising 4-cyano-4′-pentylbiphenyl molecules sandwiched between CNT-sheet-on-glass substrates, demonstrate the operation characteristics comparable to that of the conventional cell under temperature variation and ac electric field of 1?kHz. The results offer a possibility of deploying multifunctional CNT-sheet alignment layers in LC-based devices, especially in the future flexible display applications. 相似文献