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61.
Taylor Chin Ashley Phipps Frank R. Fronczek Ralph Isovitsch 《Journal of heterocyclic chemistry》2011,48(1):215-217
A novel triazene, 4‐[(E)‐2‐(4‐cyanophenyl)diazenyl]‐morpholine ( 1 ) was prepared via a diazonium ion coupling reaction between 4‐aminobenzonitrile and morpholine. The x‐ray structure of 1 was determined and evidenced π delocalization in the triazene subunit. The room temperature absorption spectrum of 1 in acetonitrile was dominated by an intense triazene‐centered π→π* transition at 325 nm. Compound 1 was observed to be luminescent, with an emission maximum at 434 nm in room temperature acetonitrile solution. The emission spectrum of 1 in propionitrile glass at 77K exhibited a narrowed emission band with a maximum at 449 nm. Broad emission from 400–700 nm with poorly resolved vibrational structure was observed from solid 1 at room temperature. J. Heterocyclic Chem., 2011. 相似文献
62.
Paddock VL Phipps RJ Conde-Angulo A Blanco-Martin A Giró-Mañas C Martin LJ White AJ Spivey AC 《The Journal of organic chemistry》2011,76(5):1483-1486
An efficient synthesis of (±)-trans,cis-4-hydroxy-5,6-di-O-isopropylidenecyclohex-2-ene-1-one (3) has been developed from acetonide-protected meso-1,2-dihydrocatechol derivative 1 via photooxygenation, then Kornblum-DeLaMare rearrangement. The product is unstable unless its 4-hydroxy group is protected, as it undergoes facile dimerization in solution to a 1:1 mixture of diastereoisomeric decahydrodibenzofurans 8 and 9. A new synthesis of the dihydrocatechol 1 from 1,3-cyclohexadiene has also been developed. 相似文献
63.
T. E. Phipps Jr. 《Foundations of Physics》1980,10(9-10):811-817
The Ehrenfest paradox is reviewed in order to categorize classes of “resolution” that are logically at least semiconsistent. Cantoni's candidate is analyzed with reference to such a taxonomy of resolutions. 相似文献
64.
Laser-driven micro-rocket 总被引:3,自引:0,他引:3
C.R. Phipps J.R. Luke G.G. McDuff T. Lippert 《Applied Physics A: Materials Science & Processing》2003,77(2):193-201
We have developed a new type of miniature rocket motor for pointing and positioning microsatellites. A specially prepared
tape with a transparent layer, through which the laser light passes, and an absorbing layer produce the thrust by the laser
ablation process. We have achieved a specific impulse of 1800 s (greater than possible with chemistry), and laser momentum
coupling coefficients of up to 50 dyn/W. The preprototype achieved 68 dyn of thrust. We discuss the target interaction physics
and some of our measurements with the preprototype thruster.
Received: 7 October 2002 / Accepted: 8 February 2003 / Published online: 28 May 2003
RID="*"
ID="*"Corresponding author. Fax: +1-505/4663-877, E-mail: crphipps@aol.com 相似文献
65.
Complexes of the type [Pd(PR3)n] (n = 3 or 4), which may be conveniently generated in situ, catalyze hydrogen-deuterium exchange reactions between D2O and various organic substrates, at ambient temperature. The reactions are most rapid for nitroalkanes, where exchange occurs exclusively at the C(1) position and allows the isolation of specifically deuterium-labeled compounds. 相似文献
66.
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69.
The tautomerism of 4-arylamino-1,2-naphthoquinones in aqueous solutions has been investigated by UV-visible absorption spectroscopy. It has been demonstrated that in strongly acidic solutions (Ph 0·8), protonation of the 2-keto group leads to 2-hydroxy-1,4-naphthoquinone-4-arylimine as the more stable tautomer. However, weakly acidic or alkaline solutions (Ph 4–13) contain 4-arylamino-1,2-naphthoquinone as the more stable tautomer. 相似文献
70.
LeClair P Swagten HJ Kohlhepp JT van De Veerdonk RJ de Jonge WJ 《Physical review letters》2000,84(13):2933-2936
Co/Al2O3/Co magnetic tunnel junctions with an interfacial Cu layer have been investigated with in situ growth characterization and ex situ magnetotransport measurements. Cu interlayers grown on Co give an approximately exponential decay of the tunneling magnetoresistance with xi approximately 0.26 nm while those grown on Al2O3 have a decay length of 0.70 nm. The difference in decay lengths can be explained by different growth morphologies, and in this way clarifies a present disagreement in the literature. For monolayer coverage of Cu, we show that the tunneling spin polarization is suppressed by at least a factor of 2 compared to Co and beyond approximately 5 ML it becomes vanishingly small. 相似文献