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141.
In this letter we describe the advantages of a dynamic optical interconnection system for parallel information processing applications. The system is based on a liquid crystal television which acts as a binary phase-only spatial light modulator. We describe example algorithms where reconfigurable interconnects would be useful and present results of several interconnection topologies which have been implemented.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994. 相似文献
142.
Robert A. Valentine Alexander Whyte Kunio Awaga Neil Robertson 《Tetrahedron letters》2012,53(6):657-660
We have prepared two new C3-symmetric, substituted-triazatruxene molecules using a facile one-pot trimerisation of 5-carboxyindole and 6-bromoindole in acetic acid using Br2, giving 2a and 3a, respectively. These were subsequently modified by the addition of six alkyl chains to the N- and carboxyl-positions of 2a giving 2b and three alkyl chains to the N-positions of 3a giving 3b. The new molecules were characterised using cyclic voltammetry, UV/vis and emission spectroscopy, DFT calculations and in the case of 3b, field-effect transistor measurements showing gate-modulated source-drain current. These represent a straightforward route to large polyaromatic molecules with easily-modified side groups and are suitable as building blocks for synthesis of functional molecules for materials. 相似文献
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Ashweek NJ Coldham I Snowden DJ Vennall GP 《Chemistry (Weinheim an der Bergstrasse, Germany)》2002,8(1):195-207
Enantiomerically enriched alpha-amino-organolithium species, in which the lithium atom is attached to a stereogenic carbon centre, have been found to be chemically stable at room temperature in a solvent of very low polarity and undergo intramolecular carbolithiation onto an unactivated alkene. The configurational stability of the chiral organolithium species, bearing a variety of N-alkenyl substituents, was probed by studying the enantiomeric purity of the cyclization products. With N-but-3-enyl-2-lithiopyrrolidine, cyclization to the five-membered ring is more rapid than racemization and a high yield of the pyrrolizidine alkaloid (+)-pseudoheliotridane was obtained with no loss of optical purity. In contrast, with N-pent-4-enyl-2-lithiopyrrolidine, cyclization to the six-membered ring was found to occur with significant loss of optical purity. The cyclization to the six-membered ring was determined to occur with a half-life, t(1/2) approximately 90 min at 23 degrees C. The epimerization of this organolithium species in hexane/Et2O 4:1 was calculated to have a half-life, t(1/2) approximately 30 min at 23 degrees C. Enhanced levels of enantioselectivity for the formation of the indolizidine ring system were obtained using an alkene bearing a terminal phenylthio substituent. With N-[(3-phenylthio)-prop-2-enyl]-2-lithiopyrrolidine, cyclization to the four-membered ring occurs with poor enantioselectivity at low temperature in THF but is highly enantioselective at room temperature in a solvent of very low polarity. 相似文献
146.
McKeown NB Hanif S Msayib K Tattershall CE Budd PM 《Chemical communications (Cambridge, England)》2002,(23):2782-2783
Network polymers exhibiting large surfaces areas (900-1000 m2g-1) are prepared by the highly efficient dibenzodioxane forming reaction between meso-tetrakis(pentafluorophenyl)porphyrin and a rigid bis(catechol) monomer. 相似文献
147.
Halfyard J Galloro J Ginzburg M Wang Z Coombs N Manners I Ozin GA 《Chemical communications (Cambridge, England)》2002,(16):1746-1747
Direct visualization of organometallic-organic and novel all-organometallic multilayer superlattices prepared by layer-by-layer assembly of cationic/anionic polyferrocenylsilane and anionic polystyrene sulfonate polyelectrolytes using a gold coating/transmission electron microscopy (TEM) technique is reported. 相似文献
148.
Butt AH Kariuki BM Percy JM Spencer NS 《Chemical communications (Cambridge, England)》2002,(7):682-683
Diels-Alder and conjugate addition reactions were used to prepare precursors to a range of fully functionalized and deoxy inositol phosphate analogues. 相似文献
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