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81.
82.
F. Dibianca R.L. Eisner W. Fickinger J.A. Malko D. Matthews J. OReilly J.F. Owens D.K. Robinson S.U. Chung S.D. Protopopescu 《Physics letters. [Part B]》1976,63(4):461-465
Data are presented on the reactions π+n → ?0+X and , respectively. Comparisons are made with related reactions at higher energies. 相似文献
83.
The negative ion mass spectra of highly fluorinated molecules with varying functionality are discussed. Attempts to obtain negative molecular ions where no positive molecular ion was observed met with little success. An interesting structural correlation for fluorinated ethers was developed based upon the observation of the abundant perfluoro alkoxide anions, CF3O? and CF3(CF2)2O?, in the negative ion mass spectrum. 相似文献
84.
Matthews JR Goldoni F Schenning AP Meijer EW 《Chemical communications (Cambridge, England)》2005,(44):5503-5505
The non-aggregating nature of a water-soluble pi-conjugated polythiophene has been characterised by concentration independent thermal denaturing. 相似文献
85.
Marshall LJ Williams JR Almond MJ Atkinson SD Cook SR Matthews W Mortimore JL 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(1-2):233-241
Three ochre samples (A (orange-red in colour), B (red) and C (purple)) from Clearwell Caves, (Gloucestershire, UK) have been examined using an integrated analytical methodology based on the techniques of IR and diffuse reflectance UV-visible-NIR spectroscopy, X-ray diffraction, elemental analysis by ICP-AES and particle size analysis. It is shown that the chromophore in each case is haematite. The differences in colour may be accounted for by (i) different mineralogical and chemical composition in the case of the orange ochre, where higher levels of dolomite and copper are seen and (ii) an unusual particle size distribution in the case of the purple ochre. When the purple ochre was ground to give the same particle size distribution as the red ochre then the colours of the two samples became indistinguishable. An analysis has now been completed of a range of ochre samples with colours from yellow to purple from the important site of Clearwell Caves. 相似文献
86.
D. M. Fatheree G. L. Deeg D. B. Matthews J. G. Russell 《Magnetic resonance in chemistry : MRC》1982,18(2):92-97
The vicinal proton coupling constants were obtained for some 6-membered ring unsaturated heterocyclic compounds. The R values and ring dihedral angles were determined and found to be consistent with half-chair conformations. Relative to saturated heterocyclic compounds, the effect of the sulfur atom on ring puckering was attenuated. However, an increase in ring puckering resulted from the sulfone group and was attributed to torsional energy. 相似文献
87.
88.
19F and 1H NMR spectra of the products of nucleophilic attack on octafluoroindene are analysed and structures assigned. The major product in the reaction of butyllithium with octafluoroindene is 3-methylheptafluoroindene, with sodium borohydride it is 2-hydroheptafluoroindene and with sodium methoxide it is 3-methoxyheptafluoroindene. Vacuum pyrolysis of undecafluorotricyclo[5.2.2.02,6]undeca- 2,5,8-triene, with elimination of C2F4, gives 6-hydroheptafluoroindene as the major product. The NMR assignments are based on the unambiguous synthesis via vacuum pyrolysis of 5,6-dihydrohexafluoroindene, 3-hydro- and 3-methyl-heptafluoroindene and the large long-range coupling of 15 Hz assigned to the F-2, F-6 interaction. 相似文献
89.
K.R. Matthews 《Journal of Number Theory》1973,5(1):16-23
The author observes that two Hermitian forms have the same largest eigenvalue. A large sieve result of Roth-Bombieri type and Selberg's upper bound sieve with a Montgomery type error term are derived. 相似文献
90.
P. Krolak R. A. Briere E. Cheu D. A. Harris K. S. McFarland A. Roodman B. Schwingenheuer S. V. Somalwar Y. W. Wah B. Winstein R. WinstonK. Arisaka D. Roberts W. Slater M. WeaverA. R. BarkerE. C. Swallow G. J. Bock R. Coleman M. Crisler J. Enagonio R. Ford Y. B. Hsiung D. A. Jensen E. Ramberg R. TschirhartE. M. Collins G. D. GollinT. Nakaya T. YamanakaP. Gu P. Haas W. P. Hogan S. K. Kim J. N. Matthews S. S. Myung S. Schnetzer G. B. ThomsonY. Zou 《Physics letters. [Part B]》1994,320(3-4):407-410
A FNAL E799 Collaboration has carried out a search for the lepton-family number violating decay π0 → μ±e using π0's produced from KL → π0π0π0 decays in flight. No events were observed. Assuming that lepton-family number violation is charge independent, the 90% confidence level upper limit on was determined to be 8.6 × 10−9. 相似文献