47,548 research outputs found
First example of solid-state luminescent borasiloxane-based chiral helices assembled through N-B bonds
No full textThe reaction between differently substituted borasiloxanes and 2,5-bis(3-pyridylethynyl)thiophene provided the first example of luminescent borasiloxane-based chiral helices held together by N-B bonds. The starting building blocks and the helices were fully characterized, and the nature of the N-B bond rationalized by means of theoretical calculations
Nonquantum Entanglement Resolves a Basic Issue in Polarization Optics
No full textThe issue raised in this Letter is classical, not only in the sense of being nonquantum, but also in the sense of being quite ancient: which subset of 4 X 4 real matrices should be accepted as physical Mueller matrices in polarization optics? Nonquantum entanglement or inseparability between the polarization and spatial degrees of freedom of an electromagnetic beam whose polarization is not homogeneous is shown to provide the physical basis to resolve this issue in a definitive manner
A complete characterization of pre-Mueller and Mueller matrices in polarization optics
No full textThe Mueller-Stokes formalism that governs conventional polarization optics is formulated for plane waves, and thus the only qualification one could require of a 4 x 4 real matrix M in order that it qualify to be the Mueller matrix of some physical system would be that M map Omega((pol)), the positive solid light cone of Stokes vectors, into itself. In view of growing current interest in the characterization of partially coherent partially polarized electromagnetic beams, there is a need to extend this formalism to such beams wherein the polarization and spatial dependence are generically inseparably intertwined. This inseparability brings in additional constraints that a pre-Mueller matrix M mapping Omega((pol)) into itself needs to meet in order to be an acceptable physical Mueller matrix. These additional constraints are motivated and fully characterized. (C) 2010 Optical Society of Americ
Intramolecular and intermolecular N-H···F-C hydrogen-bonding interactions in amine adducts of tris(pentafluorophenyl)borane and tris(pentafluorophenyl)alane
No full textThe reaction between B(C6F5)3 and NH3(g) in light petroleum yielded the solvated adduct H3N · B(C6F5)3· NH3. Treatment with a second equivalent of B(C6F5)3 afforded H3N · B(C6F5)3. Attempts to prepare the analogous alane adduct were unsuccessful and resulted in protolysis. Related compounds of the form R'R"N(H)· M(C6F5)3 were synthesized from M(C6F5)3 and the corresponding primary and secondary amines (M = B, Al; R' = H, Me, CH2Ph; R" = Me, CH2Ph, CH(Me)(Ph); R'R" = cyclo-C5H10). The solid-state structures of 13 new compounds have been elucidated by single-crystal X-ray diffraction and are discussed. Each of the borane adducts has a significant bifurcated intramolecular hydrogen bond between an amino hydrogen and two o-fluorines, while N-H···F-C interactions in the alane adducts are weaker and more variable. F-19 NMR studies demonstrate that the borane adducts retain the bifurcated C-F···H···F-C hydrogen bond in solution. Compounds of the type R'R"N(H)·M(C6F5)3 conform to Etter's rules for the prediction of hydrogen-bonding interactions
Yves Simon, Nature and Function of Authority
No full textd. B. P. Yves Simon, Nature and Function of Authority. In: Revue Philosophique de Louvain. Troisième série, tome 44, n°1, 1946. pp. 182-183
Yves Simon, Nature and Function of Authority
No full textd. B. P. Yves Simon, Nature and Function of Authority. In: Revue Philosophique de Louvain. Troisième série, tome 44, n°1, 1946. pp. 182-183
La légende de l'exorcisme d'un démon par Simon b. Yohaï
No full textBacher Wilhelm. La légende de l'exorcisme d'un démon par Simon b. Yohaï. In: Revue des études juives, tome 35, n°70, octobre-décembre 1897. pp. 285-287
Synthesis and reactivity of N-allenyl cyanamides
No full textN-Allenyl cyanamides have been accessed via a one-pot deoxycyanamidation-isomerization approach using propargyl alcohol and N-cyano-N-phenyl-p-methylbenzenesulfonamide. The utility of this novel class of allenamide was explored through derivatization, with hydroarylation, hydroamination, and cycloaddition protocols employed to access an array of cyanamide products that would be challenging to access using existing methods.</p
Smeringopus Simon 1890
No full textGenus <i>Smeringopus</i> Simon, 1890 <p> <i>Smeringopus</i> Simon 1890: 94. Simon 1893: 476. Kraus 1957: 217. Timm 1976: 70. Huber 2012: 8. Type species: <i>Pholcus pallidus</i> Blackwall, 1858 [= <i>Smeringopus pallidus</i> (Blackwall, 1858)]</p> <p> <b>Diagnosis and description.</b> See Huber (2012).</p>Published as part of <i>Yao, Zhiyuan, Kioko, Grace M., Kioko, Esther N. & Li, Shuqiang, 2019, Three new species of the spider family Pholcidae (Arachnida: Araneae) from Taita-Taveta, Kenya, pp. 114-124 in Zootaxa 4651 (1)</i> on page 118, DOI: 10.11646/zootaxa.4651.1.7, <a href="http://zenodo.org/record/3359156">http://zenodo.org/record/3359156</a>
La description dans Leçon de choses de Claude Simon
No full textDuncan Alastair. B. La description dans Leçon de choses de Claude Simon. In: Littérature, n°38, 1980. Le décrit. pp. 95-105
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