Synthesis of 3-carbonyl pyrazole-5-phosphonates via 1,3-dipolar cycloaddition of Bestmann–Ohira reagent with ynones

The present work explores the hitherto unexplored reactivity of ynones as dipolarophiles with Bestmann–Ohira reagent. The reaction offers a convenient route for the synthesis of regioisomerically pure 3,5-disubstituted or 3,4,5-trisubstituted pyrazoles in excellent yields. However, di-ynones and molecules possessing both ynone and enone functionalities provide only monocycloaddition products, whereas another multiple bond undergoes Michael addition with the methoxide anion.     

Anomalous behavior of optogalvanic signal in a miniature neon discharge lamp

A strong optogalvanic effect has been observed in a negative glow of a miniature neon discharge lamp using tunable pulse dye laser pumped by a copper vapor laser. A comparative study on temporal evolution of optogalvanic signal in a positive and negative dynamic resistance region of the discharge is described. Dye laser beam was tuned to various neon transitions 1s_i → 2p_j (Paschen notations) within 570-617 nm wavelength range. Anomalous behavior of optogalvanic signal was observed at 588.2 nm for (1s₅ → 2p₂) neon transition at low discharge current (<220 μA). This anomalous behavior is the attributes of damped oscillations of optogalvanic signal that correlate with negative dynamic resistance (dV/di < 0) of the discharge. Penning ionization at low discharge current and small energy mismatch is assumed to be the main cause of the negative dynamic resistance. Penning ionization process has been explained by resonantly ionizing energy transfer via collisions between neon buffer gas atoms in the lowest metastable state (1s₅) and electrode sputtered atoms in ground state using their partial energy level diagram.     

Evidence for a three-phonon giant resonance state in 40Ca nuclei

Inelastic scattering of 40Ca on 40Ca at 50 MeV/A has been measured in coincidence with protons at the GANIL facility. The SPEG spectrometer was associated with 240 CsI(Tl) scintillators of the INDRA 4pi array, allowing for the measurement of complete decay events. The missing energy method was applied to these events. For events with excitation energy between 42 and 55 MeV, a direct decay branch by three protons towards the low energy states of 37Cl gives the first evidence for a 3-phonon state built with giant resonances.     

Zero-field splittings in NiSiF6·6H2O as electron paramagnetic resonance thermometer

The problem of splitting of Ni²⁺ states by the electron-phonon interaction has been studied as a function of temperature. In the high-temperature region the slope of the splitting. ?D/?T = 17.58 G/°K suggests that NiSiF₆·6H₂O can be used as a thermometer.     

Interaction in mixed valence compounds

A new Hamiltonian for the interaction of magnetic impurity spin with the conduction electrons is proposed. It is found that the conduction electrons may be condensed into the spin levels. For single impurity, the exact eigenstates are found. In the case of many impurities, virtual electron exchange is predicted for the first time. A single fermion and a single phonon operator interaction leads to hybrid interaction between bands of electrons along with some interesting effects.     

Quantum mechanical calculation of Suryan’s line broadening in nuclear magnetic resonance

The first quantum theory of the classical radiation damping in nuclear magnetic resonance is presented. Relaxation times and life times arising from the interaction of nuclear spin with the radio-frequency radiation field are calculated. Second-order line shifts are predicted and the existence ofI _z andI _z ² -type operators due to photons is pointed out. The predicted line shifts as well as relaxation are found to be measurably large. Numerical estimates are given for protons in water.     

On the generalised jump of a function by its Fourier coefficients

Summary Author studies the summability (C,1+α+ρ) of the sequence nB_n(x) under weaker conditions than those ofMinakishisundaram [3] and thus generalises his theorems. on the ? Jump of a function ? and by applying a tauberian theorem obtaing a criteria for the (C, α+ρ) summability of the conjugate series.     

Satellite Lαx in the L-emission spectra of cerium-58 and praseodymium-59

The high-frequency satellite Lα^x has been observed for the first time at 2544.5 and 2447.6 X.U. in the L-emission spectra of cerium-58 and praseodymium-59 respectively. The transition energies have been calculated for the satellite, using the semiempirical Auger electron energies in the doubly ionised atoms and they have been found to be in good agreement with the measured values in all the elements in which the satellite has been reported so far.