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111.
112.
Toni Kline 《Journal of heterocyclic chemistry》1985,22(2):505-509
The regiospecific iodination of indole and 5-methoxyindole, and the elaboration of these 2-iodoindoles to the corresponding tryptamines, are described. 相似文献
113.
The Debye-Waller factor of hcp 4He at molar volumes Vm of 12.06 and 15.72 cm3 has been measured by neutron diffraction techniques. It has been found that for scattering vectors the Debye-Waller factor can be well represented by a simple Gaussian. The Debye temperatures, appropriate to the Debye-Waller factor, were found to be 99.73 K (Vm = 12.06 cm3) and 55.86 K (Vm = 15.72 cm3). No evidence was found of any forbidden reflections. 相似文献
114.
Carl N. DeSilva Kenneth A. Kline 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1968,19(1):128-139
Zusammenfassung Es werden die nichtlinearen Konstitutionsgleichungenfür ein richtungsorientiertes viskoelastisches Material mit Gedächtnis entwickelt. Die Beziehungen zwischen dieser Theorie und derjenigen der klassischen Elastizität und Viskoelastizität und einige andere Arbeiten auf dem Gebiete der Theorie der richtungsorientierten Medien werden besprochen.
Acknowledgment. This work was sponsored by the National Science Foundation under Research Grants NSF GK 1608 and GK 1769. 相似文献
Acknowledgment. This work was sponsored by the National Science Foundation under Research Grants NSF GK 1608 and GK 1769. 相似文献
115.
Derek L. Ho Boualem Hammouda Steven R. Kline 《Journal of Polymer Science.Polymer Physics》2003,41(1):135-138
The dynamic light scattering results presented in this letter demonstrate that the clustering of poly(ethylene oxide) (PEO) can be observed even in ultrapure, freshly double‐distilled and filtered deionized water. It is confirmed that the filtration of solutions removes the clustering structure and that a steady‐state amount of PEO in clusters is reformed in filtered solutions within 24 h. Adding a drop of chloroform to unfiltered aqueous solutions of PEO temporarily alters the clustering structure, but it prevents the clustering of PEO in filtered solutions. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 135–138, 2003 相似文献
116.
Achiral and chiral liquid chromatographic methods utilizing mass spectrometric detection were developed to investigate the possibility of inversion of configuration at any or all of the chiral centers of the neurokinin-1 (NK-1) receptor antagonist, aprepitant (5-[[2(R)-[1(R)-(3,5-bistrifluoromethyl phenyl)ethoxy]-3(S)-(4-fluorophenyl)morpholin-4-yl]methyl]-2,4-dihydro-[1,2,4]triazol-3-one), in-vivo, following administration of the compound to man. A structure such as aprepitant, that contains three chiral centers, may exist in eight stereochemical forms or, more specifically, as four diastereoisomeric pairs of enantiomers. The four diastereoisomers were separated from each other using a ProntoSil C18 AQ HPLC column (4.6 x 100 mm, 3 microm particles) with a mobile phase composed of acetonitrile--water (47:53, v/v%). Detection was via a single quadrupole mass spectrometer that was connected to the HPLC system via an APCI interface. Analysis of post-dose plasma samples under these conditions indicated that only aprepitant and or its enantiomer were present following oral administration of the drug. Aprepitant and its enantiomer were separated using a Chiralcel OD-H HPLC column with a mobile phase composed of hexane-isopropanol (80:20, v/v%); tandem mass spectrometric detection using an APCI interface was employed. Post-dose plasma samples analyzed using the Chiracel column were found to contain only aprepitant. The results of these experiments confirm that the products of inversion of configuration at any or all of the three chiral centers of aprepitant are not detectable in human plasma samples obtained following the administration of the drug. 相似文献
117.
Lelong G Price DL Douy A Kline S Brady JW Saboungi ML 《The Journal of chemical physics》2005,122(16):164504
Silica gels containing solutions of glucose in heavy water at different concentrations have been prepared by a sol-gel method. Dynamical studies with quasielastic neutron scattering, compared with previous results on bulk solutions, show that the dynamics of the glucose molecules are not appreciably affected by the confinement, even though the gels behave macroscopically as solid materials. Small-angle neutron-scattering spectra on the same systems, fitted with a fractal model, yield a correlation length that decreases from 20 to 2.5 nm with increasing glucose concentration, suggesting a clustering of glucose molecules in concentrated solutions that is consistent with the dynamical measurements. These two sets of results imply that 20 nm is an upper limit for the scale at which the dynamics of glucose molecules in solution are affected by confinement. 相似文献
118.
119.
Ticoş CM Wang Z Wurden GA Kline JL Montgomery DS Dorf LA Shukla PK 《Physical review letters》2008,100(15):155002
Simultaneous acceleration of hundreds of dust particles to hypervelocities by collimated plasma flows ejected from a coaxial gun is demonstrated. Graphite and diamond grains with radii between 5 and 30 microm, and flying at speeds up to 3.7 km/s, have been recorded with a high-speed camera. The observations agree well with a model for plasma-drag acceleration of microparticles much larger than the plasma screening length. 相似文献
120.
Irena Tatosian Amanda Bubas Anna Iacovino Susan Kline Luke Metzler Michael Van Stipdonk 《Journal of mass spectrometry : JMS》2019,54(9):780-789
The goals of the present study were (a) to create positively charged organo‐uranyl complexes with general formula [UO2(R)]+ (eg, R═CH3 and CH2CH3) by decarboxylation of [UO2(O2C─R)]+ precursors and (b) to identify the pathways by which the complexes, if formed, dissociate by collisional activation or otherwise react when exposed to gas‐phase H2O. Collision‐induced dissociation (CID) of both [UO2(O2C─CH3)]+ and [UO2(O2C─CH2CH3)]+ causes H+ transfer and elimination of a ketene to leave [UO2(OH)]+. However, CID of the alkoxides [UO2(OCH2CH3)]+ and [UO2(OCH2CH2CH3)]+ produced [UO2(CH3)]+ and [UO2(CH2CH3)]+, respectively. Isolation of [UO2(CH3)]+ and [UO2(CH2CH3)]+ for reaction with H2O caused formation of [UO2(H2O)]+ by elimination of ·CH3 and ·CH2CH3: Hydrolysis was not observed. CID of the acrylate and benzoate versions of the complexes, [UO2(O2C─CH═CH2)]+ and [UO2(O2C─C6H5)]+, caused decarboxylation to leave [UO2(CH═CH2)]+ and [UO2(C6H5)]+, respectively. These organometallic species do react with H2O to produce [UO2(OH)]+, and loss of the respective radicals to leave [UO2(H2O)]+ was not detected. Density functional theory calculations suggest that formation of [UO2(OH)]+, rather than the hydrated UVO2+, cation is energetically favored regardless of the precursor ion. However, for the [UO2(CH3)]+ and [UO2(CH2CH3)]+ precursors, the transition state energy for proton transfer to generate [UO2(OH)]+ and the associated neutral alkanes is higher than the path involving direct elimination of the organic neutral to form [UO2(H2O)]+. The situation is reversed for the [UO2(CH═CH2)]+ and [UO2(C6H5)]+ precursors: The transition state for proton transfer is lower than the energy required for creation of [UO2(H2O)]+ by elimination of CH═CH2 or C6H5 radical. 相似文献