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61.
We analyze the physics of spin-3 Bose-Einstein condensates, and, in particular, the new physics expected in ongoing experiments with condensates of chromium atoms. We first discuss the ground-state properties, which, depending on still unknown chromium parameters, and for low magnetic fields, can present various types of phases. We also discuss the spinor dynamics in chromium spinor condensates, which present significant qualitative differences when compared to other spinor condensates. In particular, dipole-induced spin relaxation may lead for low magnetic fields to transfer of spin into angular momentum similar to the well-known Einstein-de Haas effect. Additionally, a rapid large transference of population between distant magnetic states also becomes possible. 相似文献
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Harald Walter Guillaume Basset Tilman Beierlein Adrian Von Mühlenen Giovanni Nisato 《Journal of polymer science. Part A, Polymer chemistry》2010,48(14):1587-1593
We present an integrated system with automated sample fabrication for combinatorial investigations of solution-processed organic materials. To illustrate the applicability of the system, we give examples of typical experimental results with organic electronic devices. Organic light emitting diodes (OLEDs) based on a poly-(N-vinylcarbazole) matrix system with small molecule hole-transporter N,N′-Bis(3-methylphenyl)-N,N′-diphenyl-benzidine (TPD) and electron transporter 2-(4-tert-butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole (PBD) were optimized. In a single experimental run, the optimum range of TPD and PBD concentrations has been determined. Furthermore, we screened the influence of a gate dielectric modification with poly(methyl silsesquioxane) in organic field effect transistors and show that the choice of the material system, which constitutes the interface between the gate dielectric and the organic semiconductor, modulates the mobility of the field-effect device by more than two orders of magnitude. Finally, we present a combinatorial study of the influence of PEDOT-PSS and P3HT-PC61BM layer thickness variation in organic photo voltaic cells. To summarize, we describe the possibilities of a combinatorial tool for solution based multilayer devices comprising functional materials. The tool is applicable to a vast variety of such materials. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1587–1593, 2010 相似文献
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The β‐heteroaryl‐substituted ethanols 6 – 10 were synthesized and, together with pyridine‐2‐ethanols and pyridine‐4‐ethanols, were tested as a new type of phosphate‐protecting groups in the synthesis of oligonucleotides by the phosphotriester approach. The synthesis of 5′‐O‐(monomethoxytrityl)thymidine 3′‐(β‐heteroarylethyl 2,5‐dichlorophenyl phosphates) 13 – 17 and 21 provided useful monomeric building blocks in which the various blocking groups could be removed selectively by acid (MeOTr), oximate (2,5‐dichlorophenyl phosphate), and 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) (heteroarylethyl phosphate) treatment. The new, fully blocked dimers 38 – 41 , with β‐heteroarylethyl protecting groups in the phosphate moiety, were synthesized. The β‐heteroarylethyl groups show a broad range of stability towards base treatment in aprotic solvents depending upon the activation of the H−C(β) atoms by the heterocyclic moiety. 相似文献
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Reinhold Tacke Thomas Kornek Tilman Heinrich Christian Burschka Martin Penka Melanie Pülm Christine Keim Ernst Mutschler Günter Lambrecht 《Journal of organometallic chemistry》2001,640(1-2):140-165
The C/Si/Ge-analogous compounds rac-Ph(c-C5H9)El(CH2OH)CH2CH2NR2 (NR2=piperidino; El=C, rac-3a; El=Si, rac-3b; El=Ge, rac-3c) and (c-C5H9)2El(CH2OH)CH2CH2NR2 (NR2=piperidino; El=C, 5a; El=Si, 5b; El=Ge, 5c) were prepared in multi-step syntheses. The (R)- and (S)-enantiomers of 3a–c were obtained by resolution of the respective racemates using the antipodes of O,O′-dibenzoyltartaric acid (resolution of rac-3a), O,O′-di-p-toluoyltartaric acid (resolution of rac-3b), or 1,1′-binaphthyl-2,2′-diyl hydrogen phosphate (resolution of rac-3c). The enantiomeric purities of (R)-3a–c and (S)-3a–c were ≥98% ee (determined by 1H-NMR spectroscopy using a chiral solvating agent). Reaction of rac-3a–c, (R)-3a–c, (S)-3a–c, and 5a–c with methyl iodide gave the corresponding methylammonium iodides rac-4a–c, (R)-4a–c, (S)-4a–c, and 6a–c (3a–c→4a–c; 5a–c→6a–c). The absolute configuration of (S)-3a was determined by a single-crystal X-ray diffraction analysis of its (R,R)-O,O′-dibenzoyltartrate. The absolute configurations of the silicon analog (R)-4b and germanium analog (R)-4c were also determined by single-crystal X-ray diffraction. The chiroptical properties of the (R)- and (S)-enantiomers of 3a–c, 3a–c·HCl, and 4a–c were studied by ORD measurements. In addition, the C/Si/Ge analogs (R)-3a–c, (S)-3a–c, (R)-4a–c, (S)-4a–c, 5a–c, and 6a–c were studied for their affinities at recombinant human muscarinic M1, M2, M3, M4, and M5 receptors stably expressed in CHO-K1 cells (radioligand binding experiments with [3H]N-methylscopolamine as the radioligand). For reasons of comparison, the known C/Si/Ge analogs Ph2El(CH2OH)CH2CH2NR2 (NR2=piperidino; El=C, 7a; El=Si, 7b; El=Ge, 7c) and the corresponding methylammonium iodides 8a–c were included in these studies. According to these experiments, all the C/Si/Ge analogs behaved as simple competitive antagonists at M1–M5 receptors. The receptor subtype affinities of the individual carbon, silicon, and germanium analogs 3a–8a, 3b–8b, and 3c–8c were similar, indicating a strongly pronounced C/Si/Ge bioisosterism. The (R)-enantiomers (eutomers) of 3a–c and 4a–c exhibited higher affinities (up to 22.4 fold) for M1–M5 receptors than their corresponding (S)-antipodes (distomers), the stereoselectivity ratios being higher at M1, M3, M4, and M5 than at M2 receptors, and higher for the methylammonium compounds (4a–c) than for the amines (3a–c). With a few exceptions, compounds 5a–c, 6a–c, 7a–c, and 8a–c displayed lower affinities for M1–M5 receptors than the related (R)-enantiomers of 3a–c and 4a–c. The stereoselective interaction of the enantiomers of 3a–c and 4a–c with M1–M5 receptors is best explained in terms of opposite binding of the phenyl and cyclopentyl ring of the (R)- and (S)-enantiomers. The highest receptor subtype selectivity was observed for the germanium compound (R)-4c at M1/M2 receptors (12.9-fold). 相似文献
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As an extension of earlier work, we show that every P-local loop space, where P is a set of primes, is homotopy equivalent to the P-localization of a compact, smooth, parallelizable manifold. A similar result is also proved for P-complete loop spaces.
Received: February 2006 相似文献
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