Results 301 to 310 of about 355,905 (327)

Dissociation constants of thiophencarboxylic acids: calculation of ? constants for the thiophen ring

Journal of the Chemical Society B: Physical Organic, 1970
Dissociation constants for a number of substituted thiophen-5-carboxylic acids have been determined and used to evaluate σ constants for the thiophen molecule. The values obtained are in excellent agreement with those calculated by the method of Dewar and Grisdale and indicate that the sulphur atom has very little effect upon the transmission of ...
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Graded Rings of Theta Constants

1972
Let z → θm(τ, z) denote the familiar theta function on Cg;; we recall that m = (m′m″) is in R2g and τ in 𝔖g. If m is in Q2g, we call θm(τ, 0) a theta constant. Since in this chapter we shall mainly consider theta constants rather than theta functions, we make an agreement that θm means the function τ → θm(τ, 0) on 𝔖g; accordingly, we shall write θm(τ ...
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Remarks on rings of constants of derivations II

Communications in Algebra, 1992
Let k be a field of characteristic p>0 and D≠0 a family of k-derivations of k[x,y]. It is proved in [1] that k[x,y]D, the ring of constants with respect to D, can be generated, as a k[x p,y p]-algebra, by p - 1 elements. In this note we prove that p - 1 is the sharp upper bound of numbers of generators.
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Shirshov finiteness over rings of constants

Algebra and Logic, 1997
The author studies rings of constants for restricted differential Lie algebras acting on prime rings and having nontrivial quasi-Frobenius inner part. It is shown that, under this restriction, Shirshov's local finiteness correspondence exists between a given prime ring \(R\) and the ring of constants \(R^L\).
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Locally nilpotent derivations and their rings of constants.

2009
Given a UFD R containing Q , we study R-elementary derivations of B = R[Y1,..., Ym], i.e., R-derivations satisfying D( Yi) ∈ R for all i; in the particular case of m = 3, we will show that if R is a polynomial ring in n variables over a field k (of characteristic zero), and a1, a3, a3 ∈ R are three monomials, then the kernel of the derivation i=13ai6 ...
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Catalytic Enantioselective Ring-Opening Reactions of Cyclopropanes

Chemical Reviews, 2021
Vincent Pirenne, Bastian Muriel, Jerome Waser   +2 more
exaly  

C–C Bond Cleavages of Cyclopropenes: Operating for Selective Ring-Opening Reactions

Chemical Reviews, 2021
Rubén Vicente
exaly  

The principles, design and applications of fused-ring electron acceptors

Nature Reviews Chemistry, 2022
Jiayu Wang, Xiaowei Zhan
exaly  

On the Graded Ring of Theta-Constants (II)

American Journal of Mathematics, 1966
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Bacterial cell division: assembly, maintenance and disassembly of the Z ring

Nature Reviews Microbiology, 2009
Jeff Errington
exaly