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91.
The viscosity of a main-chain liquid crystalline polymer (anisotropic aqueous solution of hydroxypropylcellulose) is measured in the case where the liquid crystalline polymer presents a band texture and is compared to the case of a polydomain texture. 相似文献
92.
Gas chromatographic analysis of ethyl chloroformate derivatives of samples taken from the paint layers of post-Byzantine panel
paintings permitted the successful characterisation of the different binding media used in them. This paper describes an analytical
study of various post-Byzantine binding media such as egg yolk and egg/oil emulsion, using gas chromatography. The characterisation
of these icons’ binding media is an important task, as it contributes to our understanding of and the reconstruction of the
post-Byzantine artists’ palette. It also enables us to investigate the validity of our assumptions about the influences of
Venetian style on Greek icon painting techniques from the sixteenth to the early nineteenth century, which up to now have
been based on information in artists’ handbooks. The methodology involves two experimental steps: (1) hydrolysis of the proteins
and triglycerides in the binding media to obtain free amino acids and fatty acids, and (2) the formation of ethyl chloroformate
derivatives via derivatization with ethyl chloroformate (ECF). This methodology is of considerable interest, since it permits
the identifcation of the nature of the proteinaceous binders used in these works through the simultaneous derivatization and
determination of amino acids and fatty acids. Advantages of this methodology include the small quantity of sample required
and the minimum preparation time involved. The proteinaceous media can be determined based on the ratios of seven stable amino
acids, while the type of emulsions and drying oils used can be determined from the fatty acid ratio.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
93.
Mutai C Abatis D Vagias C Moreau D Roussakis C Roussis V 《Molecules (Basel, Switzerland)》2007,12(5):1035-1044
Three new pentacyclic triterpenoids: (20R)-3-oxolupan-30-al (1), (20S)-3-oxolupan-30-al (2) and (20R)-28-hydroxylupen-30-al-3-one (3), along with (20S)-3beta-hydroxylupan-30-al (4), the latter previously described as a constituent of an epimeric mixture, were isolated from Acacia mellifera. In addition, the known metabolites 30-hydroxylup-20-(29)-en-3-one (5), 30-hydroxylup-20-(29)-en-3beta-ol (6), atranorin, methyl 2,4-dihydroxy-3,6 dimethyl benzoate, sitosterol-3beta-O-glucoside and linoleic acid were found in the analyzed plant species for the first time. The structures of the new metabolites were elucidated by extensive spectroscopic analyses and their relative stereochemistry was determined by NOESY experiments. The new metabolite 3 exhibited significant cytotoxic activity against the NSCLC-N6 cell line, derived from a human non-small-cell bronchopulmonary carcinoma. 相似文献
94.
Vassilios Gregoriades 《Annals of Pure and Applied Logic》2018,169(10):1082-1116
We are concerned with two separation theorems about analytic sets by Dyck and Preiss, the former involves the positively-defined subsets of the Cantor space and the latter the Borel-convex subsets of finite dimensional Banach spaces. We show by introducing the corresponding separation trees that both of these results admit a constructive proof. This enables us to give the uniform version of these separation theorems, and to derive as corollaries the results, which are analogous to the fundamental fact “HYP is effectively bi-analytic” provided by the Suslin–Kleene Theorem. 相似文献
95.
Vassilios Hombas 《International Journal of Mathematical Education in Science & Technology》2013,44(3):432-435
The mean and variance of the number of turning points in random permutations of two kinds of distinct elements are evaluated. These results are applied to a Wald–Wolfowitz run test. 相似文献
96.
Charalambous M Moushi EE Papatriantafyllopoulou C Wernsdorfer W Nastopoulos V Christou G Tasiopoulos AJ 《Chemical communications (Cambridge, England)》2012,48(44):5410-5412
The initial use of 1,3-propanediol in mixed Mn/3d cluster chemistry has led to a Mn(III)(28)Mn(II)(8)Ni(II)(4) molecular aggregate which consists of two Mn(III)(8)Ni(2) loops and two Mn(III)(6)Mn(II)(4) supertetrahedral units and displays a high ground spin state value S(T) = 26 ± 1. 相似文献
97.
Vassilios Yannopapas 《Optics Communications》2010,283(22):4494-4498
The influence of material spatial dispersion in the degree of polarization emitted by a metallic sphere is studied by means of fluctuational electrodynamics. The corresponding cross-spectral correlation functions of the electric field are calculated on a basis of a non-local scattering T-matrix for a spherical scatterer and for non-local dielectric functions for the metal such as those provided by the hydrodynamic model and the Lindhard theory. It is shown that the main effect of the material spatial dispersion is a blue shift of the spectra of the degree of polarization which, however, diminishes as the sphere size increases. Also, at the bulk plasma frequency, a local maximum of the degree of polarization emerges as a result of the excitation of bulk plasmons which is not evident when a local dielectric function is assumed. 相似文献
98.
We analyze the relation between the density of states obtained from the energy derivative of the Friedel phase and that obtained from the Green's function of one- and quasi-one-dimensional wires with a double δ-potential. In the case of repulsive δ-potentials (in both one- and quasi-one-dimension), we show that the local Friedel sum rule is valid when a correction term is included. Various properties of the one-dimensional local density of states are also discussed. In the case of attractive δ-potentials in a quasi-one-dimensional wire, it is well known that the transmission probability may exhibit a Fano resonance (due to a zero-pole pair). In this case, we show that the local Friedel sum rule is valid provided that the tail of the quasibound state is taken into account by the integrated local density of states. In addition, we show that the density of states in a Fano resonance always has a Lorentz shape with peak position at the resonance energy regardless of the (Fano) asymmetry parameter. 相似文献
99.
Dilospiranes A and B (1 and 2), two diterpenes featuring unprecedented carbocycles, were isolated from the organic extract of the brown alga Dilophus spiralis, collected from the coast of Elafonissos Island, Greece. The structures and the relative configurations of the isolated natural products were determined on the basis of extensive analyses of their spectroscopic data. 相似文献
100.
An advanced intermediate for the synthesis of cyclopenta[g]quinazolinone-based antifolates such as (6RS)-CB300945 was prepared by a convergent methodology. The oxo-functionality required for the formation of the C-6-N-10 bond in 4 was introduced in the initial steps of the synthesis, then the tricyclic ring was constructed and finally the propargyl group was introduced using the (propargyl)Co2(CO)6+ complex without the need to protect the N-3-H or 2-hydroxymethyl functionalities. 相似文献