Application of Solid-Phase Extraction and Planar Chromatography with Diode-Array Detection to the Qualitative and Quantitative Analysis of Dyes in Beverages

JPC – Journal of Planar Chromatography – Modern TLC - The objective of this study was the use of solid-phase extraction and planar chromatography with diode-array detection for analysis...     

Role of molecular symmetries in magneto-spatial dispersional change of the refractive index in fluids

Variations in refractive index due to the (B⁰ · k) effect are calculated for a circularly polarized light wave. The effect is related with the mechanism of nonlinear electron distortion in a field B⁰ described by an i-tensor of rank 4 and the reorientation mechanism represented by the product of two c-tensors, of ranks 3 and 1. The magnetic classes of molecules admitting of these mechanisms are determined.     

线夹杂的力学模型及其界面应力分析

采用材料力学的直杆和梁的变形假定，对平面线夹杂问题提出了一种能同时考虑夹杂两侧法向应力和剪应力间断的新的力学模型，然后通过集中力作用的Ｋｅｌｖｉｎ解答，求得了单夹杂问题的基本解。文中还导出了夹杂两侧的界面应力公式。最后对夹杂端点的应力强度因子及界面应力作了计算，结果令人满意     

Complexity of linear programming

The complexity of linear programming is discussed in the “integer” and “real number” models of computation. Even though the integer model is widely used in theoretical computer science, the real number model is more useful for estimating an algorithm's running time in actual computation.Although the ellipsoid algorithm is a polynomial-time algorithm in the integer model, we prove that it has unbounded complexity in the real number model. We conjecture that there exists no polynomial-time algorithm for the linear inequalities problem in the real number model. We also conjecture that linear inequalities are strictly harder than linear equalities in all “reasonable” models of computation.     

Cognitive ability experiment with photosensitive organic molecular thin films

We present an optical experiment which permits us to evaluate the information exchange necessary to self-induce cooperatively a well-organized pattern in a randomly activated molecular assembly. A low-power coherent beam carrying polarization and wavelength information is used to organize a surface relief grating on a photochromic polymer thin film which is photoactivated by a powerful incoherent beam. We demonstrate experimentally that less than 1% of the molecules possessing information cooperatively transmit it to the entire photoactivated polymer film.     

Two-photon annihilation rate of the positronic HCN molecule

Positron binding by the HCN molecule was studied within a modified adiabatic approximation. This approach, in which the positron is treated as a light pseudonucleus with fractional charge, leads to the binding energy of 0.65?mHartree. Using effective positron mass which reproduces the Quantum Monte Carlo binding energy gives an estimation of the two-photon annihilation rate of e ⁺HCN, equal to 0.091?ns^?1.     

On amenability of two-generator groups

A discrete group G is amenable if there exists a finitely additive probability measure on G which is invariant under left translations and is defined on all subsets of G. It is proved that if the group is generated by two elements and is amenable then there are words being relators whose most of the consecutive pairs of the letters belong to a certain four-element set of pairs. This fact is applied to reproving non-amenability of a braid group. The same group provides an example showing that such type of condition is not su?cient for amenabilty.     

In a Quest for Selectivity Paired with Activity: A Ruthenium Olefin Metathesis Catalyst Bearing an Unsymmetrical Phenanthrene-Based N-Heterocyclic Carbene

Robust, selective, and stable in the presence of ethylene, ruthenium olefin metathesis pre-catalyst, {[3-benzyl-1-(10-phenyl-9-phenanthryl)]-2-imidazolidinylidene}dichloro(o-isopropoxyphenylmethylene)ruthenium(II), Ru-3 , bearing an unsymetrical N-heterocyclic carbene (uNHC) ligand, has been synthesized. The initiation rate of Ru-3 was examined by ring-closing metathesis and cross-metathesis reactions with a broad spectrum of olefins, showing an unprecendented selectivity. It was also tested in industrially relevant ethenolysis reactions of olefinic substrates from renewable feedstock with very good yields and selectivities.