Canadian Science Publishing

Công bố khoa học tiêu biểu

* Dữ liệu chỉ mang tính chất tham khảo

Sắp xếp:  
A novel type of active site at the surface of crystalline SiO2 (a-quartz) and its possible impact on pathogenicity
Canadian Science Publishing - Tập 69 Số 9 - Trang 1427-1434 - 1991
Dominique Costa, Bice Fubini, Elio Giamello, Marco Volante
A new type of surface site, different from those previously described, which gives rise to a paramagnetic oxygen species upon adsorption of O2 at low temperature, has been found at the surface of crystalline quartz. This site is abundant on freshly cleaved surfaces or on chemically etched ones but absent on crystal growth faces or on samples annealed at high temperatu...... hiện toàn bộ
Alchemists' Gold, Hg2.86 Asf6; An X-Ray Crystallographic Study of A Novel Disordered Mercury Compound Containing Metallically Bonded Infinite Cations
Canadian Science Publishing - Tập 52 Số 5 - Trang 791-793 - 1974
I. D. Brown, Brent D. Cutforth, C. Davies, R. J. Gillespie, Peter R. Ireland, J. E. Vekris
The compound Hg2.86 AsF6 belongs to the tetragonal space group I41/amd with lattice parameters a = 7.538(4) Å, c = 12.339(5) Å, and Z = 4. The structure was refined using 109 symmetry independent reflections by full matrix least-squares refinement to a final R value of 0.079. The structure may be described as consisting of oct...... hiện toàn bộ
A STUDY OF GRAFT COPOLYMERS: I. PREPARATION AND VISCOSITY BEHAVIOR
Canadian Science Publishing - Tập 36 Số 5 - Trang 858-868 - 1958
J. A. Manson, L. H. Cragg
Graft polymers were prepared by the redox polymerization of styrene in the presence of oxidized polystyrene or copolymers of styrene and 4-vinylcyclohexene-1; the maximum number of hydroperoxide groups per thousand monomeric units in the oxidized polymers was 18. Evidence that grafting had indeed occurred was obtained from measurements of monomer disappearance, of the decrease in hydroper...... hiện toàn bộ
SYNTHESIS OF β-D-MANNOSE 1,2-ORTHOACETATES
Canadian Science Publishing - Tập 43 Số 7 - Trang 1918-1923 - 1965
Mytosk Mazurek, Arthur S. Perlin
Synthesis of 3,4,6-tri-O-acetyl-β-D-mannopyranose 1,2-orthoacetates (I) from 2,3,4,6-tetra-O-acetyl-α-D-mannopyranosyl bromide (II) and various alcohols in the presence of pyridine and substituted pyridines is described. 2,6-Lutidine is a particularly effective acid acceptor in these condensations, and the use of chloroform as a diluent is advantageous. The lutidine-buffered system has af...... hiện toàn bộ
The major reducing species operative when an equimolar proportion of AlCl3 is added over a short period of time to an ether solution of equimolar proportions of LiAlH4 and acetal or ketal
Canadian Science Publishing - Tập 45 Số 3 - Trang 207-211 - 1967
U. E. Diner, H. A. Davis, R. K. Brown
The relative ease of hydrogenolysis of ether solutions of acetals or ketals is much greater with AlH2Cl than with AlH3. Conversion of the species [Formula: see text] one into the other is fast, and is accomplished by the addition of the appropriate quantity of AlCl3 or LiAlH4 to solutions of AlH3...... hiện toàn bộ
ANOMALOUS RING CLEAVAGE DURING LITHIUM ALUMINUM HYDRIDE – ALUMINUM CHLORIDE REDUCTION OF 2,2,4,4-TETRAALKYLATED-1,3-DIOXOLANES
Canadian Science Publishing - Tập 42 Số 5 - Trang 1005-1008 - 1964
B. E. Leggetter, R. K. Brown
The anomalous reductive cleavage by LiAlH4–AlCl3 of 2,2,4,4-tetramethyl-1,3-dioxolane in ether solution has been examined. Evidence supports the view that this unexpected direction of ring cleavage is due to steric repression of the formation of the intermediate oxocarbonium leading to cleavage of the C2—O1
Low Temperature Infrared Study of Hydrogen Bonding in Dissolved Pyrrole and Indole
Canadian Science Publishing - Tập 51 Số 7 - Trang 1075-1082 - 1973
Marie-Claude Bernard-Houplain, C. Sándorfy
Self-association by hydrogen bonding in the case ot pyrrole was studied by i.r. spectroscopic methods. The fundamental first and second overtones of the NH stretching vibration were measured at different concentrations and at temperatures ranging from 22 to −190 °C. The existence of at least two associated species in solution has been ascertained. 2,5-Dimethylpyrrole and indole were also ...... hiện toàn bộ
Selenium isotopic fractionation during reduction to Se0 and H2Se
Canadian Science Publishing - Tập 63 Số 11 - Trang 3195-3199 - 1985
Kamal Mohammad Asad Rashid, H. Roy Krouse
During reduction of [Formula: see text] to Se0 by NH2OH•HCl, the selenium isotope selectivity fits a two step model with the second step two orders of magnitude faster than the first. The ratios of the isotopic rate constants, k76/k82, are 1.007 and 1.020 for the first and second steps...... hiện toàn bộ
THE EFFECT OF SOLVENT AND TEMPERATURE ON THE CIS–TRANS ISOMERISM OF ORTHO-tert-ALKYL PHENOLS
Canadian Science Publishing - Tập 39 Số 3 - Trang 481-487 - 1961
K. U. Ingold, D. R. Taylor
The effects of different solvents and of a change of temperature on the infrared band due to the fundamental hydroxyl stretching vibration in several 2,6-di-t-alkyl phenols and in the corresponding ortho-t-alkyl phenols have been examined. The conclusion that the two bands observed in ortho-t-alkyl phenols represent cis and trans isomers has been confirmed. The differences in enthalpy and...... hiện toàn bộ
THE INFRARED FREQUENCIES AND INTENSITIES OF THE HYDROXYL BAND IN ORTHO-SUBSTITUTED PHENOLS
Canadian Science Publishing - Tập 39 Số 3 - Trang 471-480 - 1961
K. U. Ingold, David R. Taylor
The infrared frequencies, intensities, and half-band widths of the fundamental stretching vibration of the hydroxyl group have been measured for a large number of ortho-alkyl phenols. It has been found that phenols containing a single ortho-alkyl substituent exist as cis and trans isomers in unequal amounts, the trans isomer being the more abundant. The difference in free energy between t...... hiện toàn bộ
Tổng số: 277   
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 10