Results 241 to 250 of about 1,345,046 (291)
Some of the next articles are maybe not open access.
Chemistry of Heterocyclic Compounds, 1992
The superposition within a single molecule of competing ring-chain tautomeric pairs, the minimum structural requirement of which is the presence of one nucleophilic (OH, NH, SH, etc.) and two electrophilic (C=N, C=O, etc.) centers or the reverse, is a method of constructing ring-ring or ring-chain-ring tautomeric systems. On the basis of the structural
K. N. Zelenin, V. V. Alekseev
openaire +1 more source
The superposition within a single molecule of competing ring-chain tautomeric pairs, the minimum structural requirement of which is the presence of one nucleophilic (OH, NH, SH, etc.) and two electrophilic (C=N, C=O, etc.) centers or the reverse, is a method of constructing ring-ring or ring-chain-ring tautomeric systems. On the basis of the structural
K. N. Zelenin, V. V. Alekseev
openaire +1 more source
COUNTABLE RINGS AS ENDOMORPHISM RINGS
The Quarterly Journal of Mathematics, 1988Let \(\sum \leq \prod\) be the direct sum and product of countably many copies of the integers, let \(\sum \leq D\leq \prod\) such that D/\(\sum\) is the divisible part of \(\prod /\sum\), and let \(e_ n=(\delta_{in})_{i\in {\mathbb{N}}}\in \prod\) be the generalized n-th unit vector.
Dugas, M., Irwin, J., Khabbaz, S.
openaire +1 more source
Branch rings, thinned rings, tree enveloping rings — Erratum
Israel Journal of Mathematics, 2012zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire +2 more sources
Science, 2011
Chemistry The abstract prospect of using a circle to derive a square has intrigued scholars of geometry for centuries. Segawa et al. have now used a square to derive a circle. The arena in this case was chemistry, rather than mathematics, and the task at hand was to assemble a molecular ring composed in turn of 12 benzene rings, linked to one another ...
openaire +1 more source
Chemistry The abstract prospect of using a circle to derive a square has intrigued scholars of geometry for centuries. Segawa et al. have now used a square to derive a circle. The arena in this case was chemistry, rather than mathematics, and the task at hand was to assemble a molecular ring composed in turn of 12 benzene rings, linked to one another ...
openaire +1 more source