Salts of alkaline earth metal cations sequestered in dibenzo-18-crown-6 (Db18c6) and benzo-15crown-5 (B15c5), respectively, with I5−, I7− and I82− as the anions, have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. [Ca(Db18c6)(H2O)3](I5)2(Db18c6)(H2O) (1): monoclinic, P21 (no. 4), a = 1322.1(2), b = 1849.1(2), c = 1344.0(2) pm, β = 114.70(1)◦,V = 29...

The aim of this paper is to investigate properties of the local cohomology of rings of mixed characteristic that are analogous to Segre products of rings de ned over a eld. The main question is whether the local cohomology can be almost killed in a nite extension (we de ne what this means below). There are two reasons for considering this type of ring. First, there are special properties of the...

This paper offers an expository account of some ideas, methods, and conjectures concerning quantized coordinate rings and their semiclassical limits, with a particular focus on primitive ideal spaces. The semiclassical limit of a family of quantized coordinate rings of an affine algebraic variety V consists of the classical coordinate ring O(V ) equipped with an associated Poisson structure. Co...

In the title mol-ecule, [V(C(15)H(10)I(2)N(2)O(2))(CH(3)O)O(CH(3)OH)], the V(V) atom is coordinated by one N and two O atoms from an N'-(3,5-diiodo-2-oxidobenzyl-idene-κO)-4-methyl-benzo-hydra-zidate (L) ligand, one oxide O atom, one methano-late [V-O = 1.761 (3) Å] and one methanol [V-O = 2.383 (4) Å] O atom in a distorted octa-hedral geometry. In the L ligand, the two benzene rings are nearly...

For an o-minimal expansion R of a real closed field and a set V of Th(R)-convex valuation rings, we construct a “pseudo completion” with respect to V . This is an elementary extension S of R generated by all completions of all the residue fields of the V ∈ V , when these completions are embedded into a big elementary extension of R. It is shown that S does not depend on the various embeddings u...

Transformation of self-assembled InAs quantum dots (QDs) on InP(100) into quantum rings (QRs) is studied. In contrast to the typical approach to III--V semiconductor QR growth, the QDs are not capped to form rings. Atomic force micrographs reveal a drastic change from InAs QDs into rings after a growth interruption in tertiarybutylphosphine ambient. Strain energy relief in the InAs QD is discus...

let $r$ be an associative ring with identity and $z^*(r)$ be its set of non-zero zero divisors.  the zero-divisor graph of $r$, denoted by $gamma(r)$, is the graph whose vertices are the non-zero  zero-divisors of  $r$, and two distinct vertices $r$ and $s$ are adjacent if and only if $rs=0$ or $sr=0$.  in this paper, we bring some results about undirected zero-divisor graph of a monoid ring ov...

Let T,U and V be rings with identity and M be a unitary (T,U)-bimodule, N be a unitary (U, V )bimodule, D be a unitary (T, V )-bimodule . We characterize homomorphisms and isomorphisms of the generalized matrix ring Γ = ( T M D 0 U N 0 0 V )

We prove a version of faithfully flat descent in rigid analytic geometry, for almost perfect complexes and without finiteness assumptions on the rings involved. This extends results Drinfeld vector bundles.