Performance of different normal dispersion fibers to generate triangular optical pulses

Optical and Quantum Electronics - The nonlinear scattering of two non-collinear Gaussian pulses with different central frequencies and lengths, incident on the periodic stacks of semiconductor...     

Regeneration of Carbonyl Compounds from Oximes and Hydrazones Using Peroxymonosulfate on Silica gel under Solvent-free Conditions

In an environmentally benign solvent-free system, oximes and hydrazones are rapidly transformed into parent carbonyl compounds using peroxymonosulfate on silica gel under microwave irradiation in good to excellent yields.     

Entanglement concentration using quantum statistics

We propose an entanglement concentration scheme which uses only the effects of quantum statistics of indistinguishable particles. This establishes the fact that useful quantum information processing can be accomplished by quantum statistics alone. Because of the basis independence of statistical effects, our protocol requires less knowledge of the initial state than most entanglement concentration schemes. Moreover, no explicit controlled operation is required at any stage.     

The path-integral technique and the large-quantum-number behaviour of energy eigenvalues of coupled anharmonic oscillators

Using the path-integral technique, we derive here the large-quantum-number behaviour of energy eigenvalues of a coupled anharmonic oscillator. The result clearly shows the behaviour of the leading and the next to leading term with respect to the parameters contained in the coupled anharmonic part of the potential.     

Heterocyclic compounds. XI. Potential post-coital antifertility agents

A series of heterocyclic analogs of diarylethylene and triarylethylene were synthesized as potential anti-implantation agents. Tested in rats as oral, post-coital antifertilily agents, a few of our compounds showed some activity.     

On the luminescence of TlCl+KCl phosphor

The measurements on the luminescence spectra of TlCl+KCl mixed phosphor under low energy cathode rays at 80° K have been presented here. The reflectance as well as excitation spectra of this mixed phosphors have also been studied. The X-ray diffraction studies of the samples along with the optical studies show that the mixed phosphor consists of two phases: (1) KCl:Tl (2) TlCl:K. It has been observed that the emission bands due to thallous chloride are gradually quenched with the increase in potassium chloride content of the phosphor; further, the emission bands supposed to be due to KCl:Tl phosphors gradually appear. Since some of the emission bands obtained with KCl:Tl phosphors at high thallium content are also present in the luminescence spectra of thallous chloride it is suggested that such bands should be attributed to undissociated thallous chloride present in KCl:Tl phosphor. The quenching of thallous chloride emission by the incorporation of potassium chloride in the system has been explained as being due to the absence of stoichiometric excess of thallium in such mixed system. The results also show that the absorption spectra of the mixed system is determined by the minor components KCl:Tl. This indicates that the absorption spectra of KCl:Tl phosphor should not be affected by the presence of undissociated thallous chloride.     

NMR spectral studies. XIV. Carbon-13 nuclear magnetic resonance studies on β-lactams

Carbon-13 NMR spectra of a variety of mono- and bicyclic β-lactams have been measured and the chemical shifts of the ring carbon atoms have been assigned unambiguously. Effects of substituents on the chemical shifts of these carbons are also discussed.     

Transmission through chiral twist defects in anisotropic periodic structures

A long-lived photonic state is observed in measurements of microwave transmission through a helical stack of anisotropic overhead transparencies with various twist defects in the center of the structure. Once account is taken of absorption and of the angular spread of the source, computer simulations of transmission through a polarized localized state are in agreement with measurements. Unlike for isotropic one-dimensional bandgaps, the intensity of the localized mode is not modulated in space on a wavelength scale.