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71.
72.
D. M. Bhardwaj D. C. Jain S. Dalela Ravi Kumar N. L. Saini K. B. Garg 《Physica B: Condensed Matter》2004,350(4):366-374
We have made the XAFS measurements at the Cr–K-edge on natural Indian ruby single crystals (corundum) and its two irradiated samples with fluence 1×1012 Ni6+ and 5×1012 Ni6+ ions/cm2. Irradiated samples show interesting changes in their physical appearance. XANES measurements show progressive decrease in Δoct value on increase of Ni fluence in irradiated samples. EXAFS measurements on these samples show decrease in Cr–O distance on increase of Ni fluence. Lowering of Δoct value is correlated with the increase of Cr–O distance. 相似文献
73.
74.
Ram C. Maurya Deen D. Mishra Surendra K. Jaiswal Sudipta Mukherjee 《Transition Metal Chemistry》1992,17(5):381-383
Some new low-spin hexacoordinated cyanonitrosyl complexes of Cr1 of the type [Cr(NO)(CN)2(L)2(H2)], where L is an aromatic aldehyde oxime or Mannich base, have been prepared by the interaction or K3[Cr(NO)(CN)5]· H2O with L in aqueous AcOH, and characterized by a range of physico-chemical techniques, I.r. data suggest that all the oxime
derivatives and Mannich bases act as monodentate ligands by coordinating through the aromatic nitrogen.
TMC 2564 相似文献
75.
We have calculated total and differential cross-sections for 1s →ns (n = 2, 3, 4) electron impact excitation of hydrogen and hydrogenic ions at various energies in Coulomb-projected Born approximation.
Distortion due to static interactions, target polarization and exchange effects has been incorporated in the initial channel.
The present calculations have been compared with other theoretical and experimental results. 相似文献
76.
77.
Homopolymerization of methyl methacrylate (MMA) was carried out in the presence of triphenylstibonium 1,2,3,4-tetraphenyl-cyclopentadienylide
as an initiator in dioxane at 65°C±0·l°C. The system follows non-ideal radical kinetics (R
p
∝ [M]1·4 [I]0·44
@#@) due to primary radical termination as well as degradative chain-transfer reaction. The overall activation energy and average
value ofk
2
p
/k
t
were 64 kJmol−1 and 0.173 × 10−3 1 mol−1 s−1 respectively 相似文献
78.
A short and efficient enantioselective synthesis of sulfobacin A has been achieved using the Sharpless asymmetric dihydroxylation and the regiospecific nucleophilic opening of a cyclic sulfate as the key steps. 相似文献
79.
Dalip Kumar 《Tetrahedron letters》2004,45(14):2887-2889
Standard procedures for elaborating a quinone methide precursor for conjugation to a DNA ligand was not compatible with the presence of a vinyl group. Instead, an acrylate linker was attached by Heck coupling subsequent to o-substitution of the phenolic precursor. This transformation required protection of the phenolic group and use of ethyl acrylate rather than acrylic acid. The presence of the vinyl group also rendered the quinone methide precursor more labile to alkaline conditions than its equivalent saturated derivative and required mild conditions for coupling to the pyrrole-imidazole polyamide. 相似文献
80.
An age-dependent branching process where disasters occur as a renewal process leading to annihilation or survival ofall the cells, is considered. For such a process, the total mean sojourn time of all the cells in the system is analysed using the regeneration point technique. The mean number of cells which die in timet and its asymptotic behaviour are discussed. When the disasters arrival as a Poisson process and the lifetime of the cells follows exponential distribution, elegant inter-relationships are found among the means of (i) the total number of cells which die in timet (ii) the total sojourn time of all cells in the system upto timet and (iii) the number of living cells at timet. Some of the existing results are deduced as special cases for related processes. 相似文献