Determination of the parameters of semiconductor quantum dots in glassy matrices from the absorption and luminescence spectra and from saturation of the optical absorption

Optical methods are described for determining the parameters of semiconducting quantum dots synthesized in a glassy borosilicate matrix. The limitations of these methods and the magnitudes of their errors are analyzed. The parameters of CdS_xSe_1−x nanocrystals in the commercial glasses KS-10, OS-12, Corning 2–61, and other experimental samples are determined. Fiz. Tverd. Tela (St. Petersburg) 39, 1865–1870 (October 1997)     

Complete integrability of the supersymmetric model (cos φ)2

Complete integrability of the supersymmetric, two-dimensional sine-Gordon model of field theory within the framework of the Hamiltonian interpretation of the method of the inverse problem is proved. The classical r-matrix of the model is computed, and its equivalence to the r-matrix the Grassmann Thirring model is established. Variables of creation-annihilation type are constructed, and the spectrum of elementary excitations of the system is obtained.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 120, pp. 122–135, 1982.     

Quantum superalgebra osp(2∥1)

A quantum deformation of the simplest rank-one orthosymplectic Lie superalgebra is constructed in two ways: by changing the anticommutatoin relations of the odd generators [V₊, V_–] ~ shH, and by using a constant triangular R-matrix which is an appropriate limit of the R-matrix of the supersymmetric sine-Gordon model. A relationship between these two approaches is established. The matrix elements of the odd generators and an analog of the Casimir operator are found for finite-dimensional representations.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 169, pp. 95–106, 1988.     

Polarization observablesΣ,P y,T 1 in the reaction\vec \gamma d \to \vec pn at photon energies between 200 and 600 MeV and dibaryon resonances

The polarization observables Σ,P _y ,T ₁,P _y ^⊥ ,P _y ^∥ are derived in proton polarization measurements of the \(\vec \gamma d \to \vec pn\) reaction, using a linearly polarized photon beam of energies between 300 and 600 MeV for c.m.s. proton emission angles of 90° and 120°. A multipole analysis is performed in the framework of the gauge-invariant pole model considering theγN→πN amplitudes and the deuteron structure without dibaryon resonances and with different sets of isovector and isoscalar dibaryon resonances. It is shown that the inclusion of dibaryon resonances substantially improves agreement with experimental data.     

Supramolecular Conformational Effect in Complexations of Pectin and Chitosan Polysaccharides with Some Cephalosporin and Aminoglycoside Antibiotics

The reactions of the polysaccharides pectin (Pc) and chitosan (CTS) with antibiotics of cephalosporin and aminoglycoside series were studied. The complexation between the drugs and polymers was found to occur via hydrogen bonding. Dilution of the chitosan polycation increased the probability of occurrence of the negative ions of the cephalosporin antibiotic near the chain and lowered the probability of occurrence of the positive ions of aminoglycoside antibiotics, which affected the amount of adducts. When the pectin polyanion was diluted, the opposite situation was observed.     

Specific transport properties of medicinal chitosan films

Processes of water-vapor sorption by medicinal chitosan films and the kinetics of release of antibiotics of the cephalosporin series from these films have been studied. It has been found that the structural changes in the polymer matrix that are related particularly to its chemical modification via the interaction with drugs are the most probable cause of the deviation of the mass-transfer mechanism from the classical Fick’s mechanism.     

Lewis Acid Promoted Dearomatization of Naphthols

Two-step dearomative functionalization of naphthols promoted by Lewis acids and copper(I) catalysis was developed. Initially, Lewis acid complexation inverted the electronic properties of the ring and established an equilibrium with the dearomatized counterpart. Subsequent trapping of the dearomatized intermediate with organometallics as well as organophosphines was demonstrated and provided the corresponding dearomatized products.     

Massive Thirring model with field values in a Grassmann algebra

The inverse scattering problem method is applied to the study of the massive Thirring model with anticommuting fields. It is shown that the usual soliton is absent in the model.