1H-detected double-J-modulated INEPT-INADEQUATE for simultaneous determination of one-bond and long-range carbon-carbon connectivities and the measurement of all carbon-carbon coupling constants

We describe a new NMR experiment, (1)H-detected double-J-modulated (DJM)-INEPT-INADEQUATE, for tracing out the carbon skeleton of molecules. This experiment allows simultaneous correlation of directly bonded carbon atoms and those separated by multiple bonds, while at the same time also providing the values of all J(CC) coupling constants. This is achieved by replacing both fixed carbon-carbon coupling evolution intervals of the INEPT-INADEQUATE experiment by variable time intervals, which are incremented in concert with the DQ evolution period (t(1)). We show that the analysis of the fine structure of cross-peaks in DJM-INEPT-INADEQUATE spectra leads to accurate values of coupling constants and give guidelines for the proper usage of the method. The proposed experiment is two times less sensitive that the original INEPT-INADEQUATE experiment. We show that, using a 600-MHz cryoprobe and 20 mg of a monosaccharide, spectra that are suitable for the analysis of coupling constants as small as 2 Hz can be obtained within 24 h. Instead of performing multiple experiments, a single DJM-INEPT-INADEQUATE experiment can thus provide a wealth of information for the structural analysis of small molecules.     

The upgrade of the kinematic separator VASSILISSA—experimental results and plans

Within the past twelve years, the recoil separator VASSILISSA has been used for the investigations of evaporation residues produced in heavy-ion-induced complete fusion reactions. In the course of the experimental work, fourteen new isotopes have been identified by the parent-daughter correlations in the region of elements with 92≤Z≤94. The study of the decay properties and formation cross sections of the isotopes of elements 110, 112, and 114 was performed using high-intensity ⁴⁸Ca beams and ²³²Th, ²³⁸U, and ²⁴²Pu targets. At the beam energies corresponding to the calculated cross-section maxima of the 3n evaporation channels, the isotopes ²⁷⁷110, ²⁸³112, and ²⁸⁷114 were produced and identified. For further experiments aimed at the synthesis of the superheavy element isotopes (Z≥110) with the use of intensive ⁴⁸Ca extracted beams, improvements in the ion optical system of the separator and the focal plane detector system have been made.     

Binding of some environmental pollutants to corn protein zein studied by high-performance liquid chromatography.

The strength and the character of the binding of 12 organic solvents to the corn protein zein was determined by preparing zein-coated carbon stationary phase and by measuring the retention of solvents on a high-performance liquid chromatographic column filled with this stationary phase. The relationship between the physicochemical parameters and binding characteristics of solvents was elucidated by principal component analysis. Various interactive forces are involved in the binding of solvent to the protein. The strength of the binding is dominantly influenced by the molecular hydrophobicity while the Gaussian or non-Gaussian distribution of the adsorption strength is markedly dependent on the polarity parameters of the solvent. Sterical correspondences exerted considerable influence on each binding parameter.     

The limiting values of some perturbed angular correlations in 127I, 125I isotopes

The ‘hard-core’ and unperturbed values of some γ-γ-PAC's in ¹²⁵Xe, ¹²⁷Xe are given in terms of the integral attenuation factors $\text{G}{}_2\text{(∞)}$ for different environments.     

Structure-acidity-IR spectra correlations for p-substituted N-phenylsulfonylbenzamides

The wavenumbers of the IR absorption bands of the C=O, S=O and N-H stretching vibrations for a series of p-substituted N-phenylsulfonylbenzamides were measured in trichloromethane. The bond orders, Mulliken charges, charge densities and heats of formation were calculated using the PM3 method. Fifty significant mutual mono parameter (MP) and six dual parameter (DP) correlations were found for the IR spectral, theoretical structural data, substituent constants and previously reported dissociation constants in five polar organic solvents. The transmission of the substituent effects has been discussed and the solvent effect on the slopes of some linear correlations was evaluated using different solvent parameters. The results showed that the factors describing the electronic structure and controlling the dissociation equilibrium and the IR spectra properties of p-substituted N-phenylsulfonylbenzamides must be the same.     

On a theorem of Jaworowski on locally equivariant contractible spaces

Ancel's method of fiberwise trivial relations is applied to the problem of characterization of absolute equivariant extensors. We obtain a generalization of Jaworowski's theorem on characterization of equivariant extensors lying in to the case when the space is infinite-dimensional, has infinitely many orbit types and the acting compact group is not necessarily a Lie group.

     

Distributed-order fractional wave equation on a finite domain: creep and forced oscillations of a rod

We study waves in a rod of finite length with a viscoelastic constitutive equation of distributed fractional order type for the special choice of weight functions. Prescribing boundary conditions on displacement and stress, we obtain, as special solutions, cases corresponding to creep and forced oscillations. In solving system of differential and integro-differential equations, we use the Laplace transformation in the time domain.