The title compound, a natural b,d-seco-limonoid, C(27)H(34)O(8)·H(2)O, and known as Swietenolide monohydrate, has been isolated from S. macrophylla King. In the molecular structure, the four fused six-membered rings adopt twist-boat (ring A), approximate chair (ring B), envelope (ring C) and half-chair (ring D) conformations. The attached furan ring is essentially planar. O-H⋯O hydrogen bonds a...

(1.5) Proposition Let R be a semisimple ring. Then R is isomorphic to a finite direct product ∏s i=1 Ri, where each Ri is a simple ring. (1.6) Proposition Let R be a simple ring. Then there exists a division ring D and a positive integer n such that R ∼= Mn(D). (1.7) Definition Let R be a ring with 1. Define the radical of R to be the intersection of all maximal left ideals of R. The above defi...

a topoframe, denoted by $l_{ tau}$,  is a pair $(l, tau)$ consisting of a frame $l$ and a subframe $ tau $ all of whose elements are complementary elements in$l$. in this paper, we define and study the notions of a$tau $-real-continuous function on a frame $l$ and the set of realcontinuous functions $mathcal{r}l_tau $ as an $f$-ring.we show that $mathcal{r}l_{ tau}$is actually a generalization ...

for a fixed positive integer , we say a ring with identity is n-generalized right principally quasi-baer, if for any principal right ideal of , the right annihilator of is generated by an idempotent. this class of rings includes the right principally quasi-baer rings and hence all prime rings. a certain n-generalized principally quasi-baer subring of the matrix ring are studied, and connections...

We theoretically investigate the critical bias current $j_c$ for a superconducting (SC) ring in magnetic field. Based on Ginzburg-Landau theory, we show that exhibits Little-Parks (LP) oscillation as function of flux passing through ring, similarly to LP SC transition temperature. It is also found spin-triplet ${\bf d}$-vector rotates yield larger $j_c$, forming texture along circumference ring...

A novel design of Dual-Core Photonic Crystal Fiber (DC-PCF) with silica-air microstructures is proposed in this paper. Nonlinearity and confinement loss of DC-PCF are evaluated by using a Full-Vectorial Finite Element Method (FV-FEM) successfully. By optimizing the geometry of three ring DC-PCFs, a high nonlinearity (52w-1km-1) and low confinement loss (0.001dB/km) can be achieved at 1.55μm wav...

Let R be a 2-torsion free ring and L a Lie ideal of R. An additive mapping F : R ! R is called a generalized derivation on R if there exists a derivation d : R to R such that F(xy) = F(x)y + xd(y) holds for all x y in R. In the present paper we describe the action of generalized derivations satisfying several conditions on Lie ideals of semiprime rings.

An ensemble of JHH, JCH, and JCC values was measured in aqueous solutions of methyl α- and β-d-idohexopyranosides containing selective 13C-enrichment at various carbons. By comparing these J-couplings to those reported previously in the α- and β-d-idohexopyranoses, methyl glycosidation was found to affect ring conformational equilibria, with the percentages of 4C1 forms based on 3JHH analysis a...

FT-SERS (Fourier Transform Surface Enhanced Raman Scattering) of adriamycin and its complex with DNA is reported. It is shown that in agreement with previous Raman studies the interaction of adriamycin  with DNA takes place through an intercalation mechanism. The presence of a new band at 731 cm-1 suggests that ring D of adriamycin is not involved in the intercalation process.