The problems of constructing accurate and stable algorithms for solving inverse problems of mathematical physics are at the forefront of modern computational mathematics due to the ever-increasing ...number of applications of such problems in physics and technology, as well as to the properties of these problems, which greatly complicate their numerical solution. In this paper, we consider the problem of numerical solution of one of such problems, known as the inverse problem of heat transfer. The numerical method for solving the inverse problem of heat transfer uses the apparatus of hypersingular integral equations. As far as the authors know, this approach to the construction of methods for solving the inverse problem of heat transfer is used for the first time. The numerical method described in the paper makes it possible to successfully find an approximate solution to the inverse problem of heat transfer, including the case of significant errors in the initial data. The solution of a model example demonstrates the efficiency of the method proposed.
The amplitude and width of the ultrashort pulses depend on the performance of the generator's electronic elements. The usage of step recovery diodes (SRDs) with picosecond switching time can lead to ...a significant increase in device cost. In this letter, nonlinear transmission line (NLTL) was built and tested using commercial-off-the-shelf components to improve the performance of the generator that is based on inexpensive diodes. The method to control output pulse duration by keeping the constant amplitude was proposed. Measurement results show that generated ultrashort pulse can be compressed using NLTLs and the output amplitude of the compressed pulse is 54 V and the duration is 240 ps.
Lenses of eclogites (the Tulepsai complex) that formed at the peak of metamorphism at
P
= 15 kbar and
T
= 700–750°C and experienced decompression at 12 kbar (granulite-facies metamorphism) are ...located among the amphibolite sequences in the Eastern Mugodzhar Zone. The insignificant difference between the age of zircon cores, which, we believe, formed under the conditions of the eclogite-facies metamorphism (374 ± 4 Ma) at depths of 50–60 km (?) and the age of their rims (372 ± 6 Ma) formed during the isothermal decrease in pressure up to 12 kbar (25–35 km?) may indicate a rapid uplift of eclogites from considerable depths. Rutile extracted from eclogites yields a U–Pb age at 360 ± 2 Ma and reflects a later stage of rock transformation at 630–690 ± 40°C. The Maksyutov eclogite–glaucophane–schist and Tulepsai complexes are structural analogs of similar age and compose the lower allochthons on different branches of the Magnitogorsk synform. The complexes were formed in a similar geodynamic setting at the arc–continent collision.
This paper is devoted to approximate methods of solving direct and inverse problems for parabolic equations. An approximate method to solve the initial problem of a multidimensional nonlinear ...parabolic equation has been proposed. It is based on reducing the initial problem to a nonlinear multidimensional Fredholm intergral equation of the second kind, which is approximated by a system of nonlinear algebraic equatiions using a method of mechanical quadratures. In constructing a computational scheme, the points of local splines have been applied for optimal with respect to order approximation of a functional class that contains the solutions of parabolic equations. For the numerical implementation of the computational scheme, we have used the generalization of a continuous method of solving nonlinear operator equations that is described in the paper. In addition, the inverse problem of a parabolic equation with a fractional order derivative with respect to a time variable has been studied. Approximate methods of determining the fractional order of the time derivative and a coefficient at a spatial derivative have been proposed.
•Laser method for synthesis of bimetallic materials for enzyme-free microbiosensors.•Relationship between the structure of complexes and the properties of microbiosensors is shown.•The gap in ...knowledge about the structure of bimetal wine complexes has been filled.
The use of laser methods for synthesizing new materials for non-enzymatic electrochemical microsensors for express analysis of biological fluids is a promising scientific question.
Laser-induced chemical liquid phase deposition is the laser deposition of invisible miniature bimetallic deposits from aqueous solutions of salts and complexes of transition metals. Bimetallic complexes containing two transition metal cations in the shell of one ligand are of increased interest. There is an information gap in this area even for ligands such as tartrate. The studies carried out make it possible to obtain new information on the structure of bimetallic tartaric complexes in solutions containing simultaneously copper, nickel, silver, iron, and cobalt.
Metagabbroid garnet amphibolite formed after high-pressure granulite with an estimated
P–T
peak of 12–16 kbar at 700–790°C occurs at the sole of the Kempirsai ophiolite allochthon (Southern Urals). ...Garnet amphibolite includes high-Fe varieties with the assemblages of garnet and relics of pyroxene, as well as high-alumina rocks composed of garnet, pyroxene, corundum, and sapphirine. The Ediacaran and Early–Middle Palaeozoic sequences underlying the allochthon were metamorphosed under the conditions of amphibolite facies. Our studies were aimed at estimation of the peak metamorphic age of garnet amphibolite. The mean
206
Pb/
238
U (SIMS, SHRIMP II) age obtained for the zircons from garnet amphibolite is 392 ± 4 Ma. The estimated age characterizes the timing of metamorphism related to mantle magmatism accompanying obduction.
Detailed structural analysis of the formations of the Maksyutov eclogite–glaucophane–schist complex in the Southern Urals has been carried out. U–Pb (LA-ICP-MS) isotopic dates of detrital zircons ...from quartzites of the Yumaguzino and Karamala groups (tectonostratigraphic units) making up the complex were obtained. The data show that both groups are similar in age but differ in the facies formations that comprise the proximal (Yumaguzino Group) and distal (Karamala Group) regions of the Paleozoic margin of the Baltica paleocontinent. The alternation of these groups in the Maksyutov Complex is explained by their tectonic juxtaposition during the formation of the scaly-thrust structure of this complex. Formations of the Maksyutov Complex subsided in the subduction zone beneath the Magnitogorsk island arc and were subjected to fold deformations during the subsequent exhumation. Four deformation stages have been established during the structural evolution of the complex. The first stage is associated with the development of the southwest-vergent folds and sheath folds F
1
and corresponds to the eduction of the formations of the Maksyutov metamorphic complex from the subduction zone of the Magnitogorsk island arc in the southwestern direction (in modern coordinates) in the middle of the Famennian–Late Devonian. The second stage manifests itself in the development of the southeast-vergent folds F
2
, which are most common in the Maksyutov Complex. This stage is associated with an oblique sinistral collision of the Magnitogorsk island arc with the Baltica margin in the Late Devonian. At the third deformation stage, the west-vergent folds F
3
were formed, caused by movements during the Late Paleozoic continental collision in the Main Ural Fault Zone. Postcollisional shear movements at the fourth deformation stage, marked by the development of folds F
4
with steeply dipping hinges, completed the main stage of the structural evolution of the region.
This paper reports new data on the Early Ordovician age established for granitoids of the gabbro—tonalite–trondhjemite complex in the Denisovka ophiolite zone (suture) on the boundary between the ...Paleozoic structures (Paleozoides) of the Urals and Kazakhstan. The ages of 482.6 ± 3.6 Ma and 486.2 ± 6.7 Ma were established by the U/Pb method (SHRIMP II) on the age data for zircon extracted from granitoids. The plutonic complex associates with the Early–Middle Ordovician effusive complex, composed of a series of rocks differentiated from basalts to rhyolites. The volcano-plutonic association was formed in the supra-subduction settings, as is evidenced by the composition of the rocks.
New data on the Vendian age of the volcanogenic–sedimentary sequence of the Uraltau zone (Southern Urals) were obtained. The U/Pb (SHRIMP-II) isotope age obtained for zircons from rhyolite tuffs is ...591.5 ± 3.5 Ma. The sequence under consideration is intruded by Vendian granites and overlain unconformably by Ordovician terrigenous and volcanogenic deposits. The composition of Vendian volcanics and granites testifies that they were formed in a suprasubduction setting at the continental margin, complexes of which are known in the Middle and Northern Urals.
The study is focused on mesostructural folded parageneses of the Taldyk antiform (a.k.a. Taldyk block) located in the East Mugodzhar zone. The sequence of their formation is established; the ...structural evolution of the study area is investigated, and four stages of deformation are identified. The NW-trending folds F1 with SE-vergence formed during the first stage of deformation, DI. The geodynamics and timeline of this stage remain unclear. The W-E-trending folds F2 with E-vergence are related to tectonic movements that took place at stage DII. In the western limb of the antiform, stage DII is evidenced by folds overturned towards the south-east. In the eastern limb, folds plunge to the east and northeast. These fold structures are probably related to the Devonian subduction-obduction processes. At stage DIII, thrusting of the Taldyk antiform over the West Mugodzhar zone and folding F3 with W-vergence is related to the Ural continental collision in the Late Paleozoic, which completed the geodynamic evolution of the Ural paleo-ocean. At stage DIV, postcollisional shearing is evidenced by folds F4 with steeply dipping hinges, which completed the structural evolution of the study area.
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