Theory of absorption and amplification spectra of a weak electromagnetic field by two-level quantum systems

A theory is developed of the absorption and amplification spectra of a weak (probe) electromagnetic field (EMF) by open two-level quantum systems in a strong quasiresonant EMF, assuming separability of the triplet spectrum components. The theory describes the intensity and the form of the spectral lines for arbitrary intensities and detunings of the strong EMF, and also the dependence of the parameters of the adiabatic relaxation on the frequency of the weak EMF. The influence of nonlinear dynamic effects (NDE) due to the dependence of the relaxation on the EMF parameters on the shape of the spectral lines is investigated. It is shown, in particular, that under certain conditions the NDE can lead to a nonlinear dynamic transformation of the dispersion of the sideband dispersion lines into Lorentzian lines and to a considerable increase of the absorption in the central region of the spectrum. Particular attention is paid to an investigation of the NDE on the characteristics of the central component of the spectrum. Methods and results of an investigation of the spectra in a basis of unperturbed wave functions in in a basis of dressed states are compared.Radiophysics Division, Lebedev Physics Institute. Translated from Preprint No. 117 of the Lebedev Physics Institute, Academy of Sciences of the USSR, Moscow, 1990.     

The gap between monotone and non-monotone circuit complexity is exponential

A. A. Razborov has shown that there exists a polynomial time computable monotone Boolean function whose monotone circuit complexity is at leastn ^{c losn} . We observe that this lower bound can be improved to exp(cn ^1/6–o(1)). The proof is immediate by combining the Alon—Boppana version of another argument of Razborov with results of Grötschel—Lovász—Schrijver on the Lovász — capacity, of a graph.     

13C NMR spectra of biologically active compounds

The diastereomeric effects on the¹³C NMR chemical shifts of thirteen epimeric pairs of 16-aryloxy-11-deoxyprostaglandins of the E₁ and F₁ series caused by the change in the configuration of the 15-hydroxy group, which are differential parameters for assigning epimers to the 15- and 15-stereochemical series, have been determined.For Communication (VIII), see [1].Institute of Chemistry, Bashkir Scientific Center, Urals Branch, Academy of Sciences of the USSR, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 123–128, January–February, 1991.     

Pyrimidine derivatives. 58. A new method for synthesizing 7-aminopyrrolo[2,3-d]-pyrimidine derivatives

A number of aldimines of 7-aminopyrrolo[2,3-d]pyrimidine have been synthesized by the action of bromine on hydrazones of 5-allyl-4-hydrazinopyridine. The structures of the compounds obtained were confirmed by IR spectroscopy and mass spectrometry.For Communication 57, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 678–681, May, 1985.     

Analogs of pyrimidine mono- and polynucleotides

The corresponding monophosphates, cyclophosphates, and , -diphosphates were obtained by phosphorylation of 1-(1, 4-dihydroxy-2-pentyl) thymine, 1-(1, 3-dihydroxy-2-propyl) uracil, and their derivatives with selective protection of one of the hydroxyl groups. 2-Cyanoethyl phosphate (CEP) in the presence of N, N-dicyclohexylcarbodiimide (DCC), polyphosphoric acid, and pyrophosphoryl chloride were used as phosphorylating agents. The dependence of the yields of the products of phosphorylation of 1-(1, 4-dihydroxy-2-pentyl) thymine with CEP on the ratio of the reacting substances and the reaction time was studied. The monophosphates were cyclized under the influence of DCC. In the case of 1-(1, 3-dihydroxy-2-propyl) uracil 1-phosphate a dimeric phosphate was obtained in addition to a cyclophosphate. The acid hydrolysis of the cyclophosphates was investigated.See [1] for communication V; see [2] for a preliminary communication.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 678–683, May, 1978.     

Derivatives of l-H-aziridine-2-carboxylic acid

The reaction of 1,1-dimethylhydrazine with acrylic acid derivatives gave a number of 1,1-dimethyl-2-(2-substituted ethyl)hydrazines, which were quaternized by alkylating agents. The transformations of 1,1,1-trimethyl-2-(2-substituted ethyl)hydrazinium salts in the presence of sodium methoxide were investigated. 2-Cyano-, 2-carbomethoxy-, 2-carbethoxy-, and 2-carbodiethylamidoaziridines and a number of products of decomposition of the starting salts were obtained.