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1.
We give an iterated function system (IFS) on the plane with the circle as attractor. In doing this, we also give a sufficient condition for radially contracting functions on the plane (or on Rn) to be a contraction. A counterexample shows that radial contractiveness is not enough to be a contraction.  相似文献   
2.
A series of new 1,2,4-substituted hexahydropyridazines was prepared in order to evaluate qualitatively and quantitatively the role and influence of substituents on the biological activity of this system. An X-ray structural investigation of 4-hydroxyimino-2-methyl-1-phenethylhexahydropyridazine was performed. The compounds considered exhibit moderate local anesthetic, antihistaminic, and anticonvulsive activity.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 539–541, March, 1993.  相似文献   
3.
We consider the photoproduction processes, introduced in the SU(2)×U(1) theory, whereby vector W and Z and scalar bosons are produced on an electron. The differential cross sections for the distribution of the leptons and bosons produced as well as the total cross sections of the processes, are calculated and analyzed. The asymptotic values of the total cross section are also given.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 44–50, April, 1984.  相似文献   
4.
Mannich condensation of 1-(ethylsulfanyl)alkan-2-ols, formaldehyde, and secondary amines taken in equimolar amounts was used to obtain new amino derivatives of 1-(ethylsulfanyl)alkanes. The structure of the thus synthesized compounds was confirmed by elemental analysis, IR and 1H NMR spectroscopies, and mass spectrometry. It is shown that the obtained compounds can be used as antimicrobial additives to lubricating oils and antiseptic substances against bacteria and fungi.  相似文献   
5.
The temperature dependence of the Hall coefficient of a single crystal of the p-Sb2Te2.9Se0.1 solid solution grown by the Czochralski technique is studied in the temperature range 77–450 K. The data on the Hall coefficient of the p-Sb2Te2.9Se0.1 are analyzed in combination with the data on the Seebeck and Nernst–Ettingshausen effects and the electrical conductivity with allowance for interband scattering. From an analysis of the temperature dependences of the four kinetic coefficients, it follows that, at T < 200 K, the experimental data are qualitatively and quantitatively described in terms of the one-band model. At higher temperatures, a complex structure of the valence band and the participation of the second-kind additional carriers (heavy holes) in the kinetic phenomena should be taken into account. It is shown that the calculations of the temperature dependences of the Seebeck and Hall coefficients performed in the two-band model agree with the experimental data with inclusion of the interband scattering when using the following parameters: effective masses of the density of states of light holes md1*≈ 0.5m0 (m0 is the free electron mass) and heavy holes md2*≈ 1.4m0, the energy gap between the main and the additional extremes of the valence band ΔEv ≈ 0.14 eV that is weakly dependent on temperature.  相似文献   
6.
The kinetics of the formation of liquid products from catalytic cracking gases over a zeolite-containing catalyst in a flow reactor in the temperature range from 260 to 420°C at GHSV = 30–264 h–1 and an on-stream time of 5–25 s has been investigated. A kinetic model for the process proceeding according to a likely scheme is proposed. The rate constants and activation energies of certain reactions involved in the process have been determined. A mathematical model of the process taking into account the mass and heat balances, as well as hydrodynamic conditions, has been developed. The concentration and temperature fields and the pressure over the catalyst bed height have been calculated. The target product yield on has been plotted as a function of the on-stream time.  相似文献   
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Russian Chemical Bulletin - Acylation of ivermectin 5-oxime was first studied. Procedures for selective acylation of ivermectin 5-oxime either selectively at 5-oxime group or at both 5-oxime group...  相似文献   
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