Fullerite with intercalated freon Ch2F2

Fullerite C₆₀ with intercalated CH₂F₂ (Freon-32) was prepared for the first time. The sample was studied by elemental analysis, X-ray powder diffraction, mass spectrometry, and IR spectroscopy. The composition of the sample was found to be (CH₂F₂)C₆₀. The sample had a face-centered cubic lattice with the lattice parameter (1.4284 nm) much larger than that of pure fullerite (1.416 nm). The gas released from the sample during heating in a vacuum to 450°C largely consisted of initial Freon (mass spectrometry data); no Freon destruction products were observed at this temperature. The C-F stretching vibration frequency (1058 cm^?1) was shifted in (CH₂F₂)C₆₀ by 30 cm^?1 toward lower wave numbers compared with the gas phase. The absorption bands at 1182 and 1428 cm^?1 (IR active modes (F _1u ) of high-symmetry (I _h ) C₆₀ molecules) did not change their positions in the intercalate.     

Inhomogeneous two-dimensional structures in liquid crystals

Localized axisymmetric inhomogeneous states with a continuous distribution of the director field can exist in nematics. Such structures are compressed into dense filaments under the influence of a magnetic or electric field. It is hypothesized that the given states can be achieved in filamentary nematic textures. This model is an alternative to the conventional disclination model. Two types of lattices of axial structures can exist in the entire range of existence of the modulated state. Axial structures with a kernel of finite radius can exist in cylindrical capillaries. The structure and equilibrium dimensions of the axial states are easily altered over a wide range under the influence of an applied field. The feasibility of utilizing isolated axial structures and lattices of such structures in optical data processing and imaging devices is discussed. The most promising outlook in this regard is for modulated states and axial structures in chiral liquid crystals exhibiting spontaneous polarization. Zh. éksp. Teor. Fiz. 113, 1675–1697 (May 1998)     

Models for capacitated lot-sizing problem with backlogging,setup carryover and crossover

Setup operations are significant in some production environments. It is mandatory that their production plans consider some features, as setup state conservation across periods through setup carryover and crossover. The modelling of setup crossover allows more flexible decisions and is essential for problems with long setup times. This paper proposes two models for the capacitated lot-sizing problem with backlogging and setup carryover and crossover. The first is in line with other models from the literature, whereas the second considers a disaggregated setup variable, which tracks the starting and completion times of the setup operation. This innovative approach permits a more compact formulation. Computational results show that the proposed models have outperformed other state-of-the-art formulation.     

Stability and convergence of the spectral Lagrange-Galerkin method for mixed periodic/non-periodic convection-dominated diffusion problems

We present a convergence analysis of the spectral Lagrange-Galerkinmethod for mixed periodic/non-periodic convection-diffusionproblems. The scheme is unconditionally stable, independentof the diffusion coefficient, even in the case when numericalquadrature is used. The theoretical predictions are illustratedby a series of numerical experiments. For the periodic case,our results present a significant improvement on those givenby Süli & Ware (1991) SIAM J. Numer.Anal.28, 423-445).     

Role of Fullerene–Nitrogen Complexes of Alkali Metals in C60-Catalyzed Nitrogen Fixation

Russian Journal of Physical Chemistry A - The key stage of the activation of a nitrogen molecule upon the catalytic reduction of N2 to ammonia in an aqueous medium in the presence of a complex of...     

Synthesis of 4H-pyrrolo[3,2,1-ij]quinoline-1,2-diones containing a piperazine fragment and study of their inhibitory properties against protein kinases

Russian Chemical Bulletin - Hybrid compounds based on 4,4,6-trimethyl-4H-pyrrolo[3,2,1-ij]quinoline-1,2-diones containing a piperazine fragment were synthesized. Their inhibitory activity against...     

Almost everywhere convergence of a wavelet thresholding risk estimate in a model with correlated noise

The problem of estimating a function in a model with correlated noise by thresholding its wavelet decomposition coefficients is considered. The risk estimate using this approach is shown to be strongly consistent.