We present the Vernier optical fiber Shape-8 double-ring resonator consisting of two optical fibre rings with a gain coupling cofficent path connecting the two rings. One of the ring is twisted to form an enclosed Shape-8. Photonic graphical techniques are applied to obtain the transfer functions between input and output ports of the photonic circuit. The Shape-8 Vernier Double Ring optical res...

in this paper, we introduce a class of $j$-quasipolar rings. let $r$ be a ring with identity. an element $a$ of a ring $r$ is called {it weakly $j$-quasipolar} if there exists $p^2 = pin comm^2(a)$ such that $a + p$ or $a-p$ are contained in $j(r)$ and the ring $r$ is called {it weakly $j$-quasipolar} if every element of $r$ is weakly $j$-quasipolar. we give many characterizations and investiga...

A compact and highly sensitive liquid refractive index (RI) sensor using Vernier effect achieved with embedded double-ring resonator is proposed demonstrated. Unlike these conventional sensors cascaded resonators to achieve effect, in our (EDRS) the sensing ring on reference ring, which makes more while achieving high sensitivity. Our typical fabricated EDRS polymer material, has a footprint of...

Phycoerythrobilin and phycocyanobilin are covalently attached to the apoproteins of phycoerythrins and phycocyanins. One linkage consists of an ester bond between the hydroxy group of a serine residue and the propionate side chain on one of the inner pyrrole rings (probably ring C). The other linkage is a labile thioether bond between a cysteine residue and the two-carbon side chain on pyrrole ...

Aiming at the sealing failure of a water quality monitoring system in low-temperature environment, double rubber O-ring structure was designed, and its performance low temperatures studied. Finite element software ANSYS constructed structure, change process standard temperature installation studied by two-dimensional axisymmetric model. The results show that equivalent strain stress an increasi...

We present two models of coherent quantum switches constructed from a single-electron quantum ring and a double quantum dot, respectively. The systems are driven by picosecond laser pulses obtained using quantum optimal control theory. The optimized pulses generate electron-current flips in the ring (magnetic switch) and electron transport in the double dot (charge switch) in significantly shor...

In the biologically active title compound, C26H26O5, the pyran ring of the chromene unit adopts a half-chair conformation. The C=C double bond of the propenone unit exhibits a trans conformation and the carbonyl group is syn conformation to the double bond. The dihedral angle between the benzene ring and the benzopyran-one moiety is 31.54 (4)°. The mol-ecular structure is stabilized by an intra...

Oxidative cyclization of the pyrrole–imidazole alkaloids oroidin and sventrin in DMSO/TFA (1:1) yields oxazolines via nucleophilic attack of the carbonyl oxygen at the alkenyl double bond. Oxidation takes place in the benzylic position of the imidazole ring. On prolonged reaction times, the oxazoline ring is hydrolyzed yielding the corresponding ester of pyrrole-2-carboxylic acid containing a f...

BACKGROUND Splitting of the lens capsule with a double-ring contour during continuous curvilinear capsulorrhexis has not often been reported. CASE An 86-year-old woman underwent phacoemulsification cataract extraction with intraocular lens implantation in the right eye. Preoperatively, the anterior lens capsule appeared normal. OBSERVATIONS A double-ring sign was observed during capsulorrhe...