International Applied Mechanics - The theorems (statements) on the existence of attractor are proved. A generalized Shilnikov theorem is formulated. In the expression for the saddle of a homoclinic... 相似文献
We presented exact analytical formulae and numerical calculation of diffusitivity curves with different law for a local pore behavior and have obtained critical exponent, different from conductivity. The connectivity percolation theory was built only on the conductivity, (the diffusion critical exponent was supposed to be equal to the conductivity exponent) and therefore sees only one side of problem-the scalar side. In many topological problems involving mechanical properties and fluid flow the connectivity scalar percolation geometry does not enough to apply.
One of the most useful aspects of percolation is that many very complicated systems have the same behavior with the same critical exponents. Universality of vector percolation is shown in the coincidence between the experimental measured relative hydraulic permeability of fluid and gas flow through unconsolidated sand and effective conductivity and diffusitivity curves of the bond–site percolation models. Comparisons of our calculation results to natural matches are quite good. We have argued that experimental data may be interpreted as a variant of pure vector percolation and to belong to the same universality class. 相似文献
Institute of Biology, Ufa Scientific Center, Russian Academy of Sciences, Ufa, fax (3472) 35 6103. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 755-756, September-October, 1995. Original article submitted September 6, 1994. 相似文献
Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Prikladnaya Mekhanika, Vol. 27, No. 7, pp. 103–109, July, 1991. 相似文献
Glassy-carbon electrodes (GCEs) are modified with preoxidized multiwalled carbon nanotubes (CNTs). According to the data of atomic force microscopy, the layers of CNTs on GCEs possess a homogeneous nanostructurized surface. The voltammetric properties of a GCE/CNT depend on the modifier load. Guanine and deoxyguanosine monophosphate are strongly adsorbed on GCE/CNT and oxidized at +690 and +930 mV (pH 7.0), respectively. The oxidation current of guanine DNA nucleotides adsorbed on a GCE/CNT is significantly higher for the thermally denaturated biopolymer than for the native one. Our results are of interest for the development of sensors based on the electrochemical properties of nucleic acids. 相似文献
The intramolecular Diels—Alder reaction of readily accessible 4-substituted 4-(N-furfuryl)aminobut-1-enes was studied and a new one-step method was developed for the synthesis of 6,8a-epoxy-1,2,3,4,4a,5,6,8a-octahydroisoquinoline (3-aza-11-oxatricyclo[6.2.1.01,6]undec-9-ene) derivatives. The [4+2]-cycloaddition proceeds stereoselectively to form exo-adducts. The influence of substituents at the nitrogen atom in 4-(N-furfuryl)aminobut-1-enes on the cycloaddition pathway was examined. 相似文献