Vescì Nacyânalʹnaj akadèmìì navuk Belarusì最新文献

{"title":"Silicon wafer bonding by the glass-like sol-gel formed nanocomposite","authors":"V. E. Gaishun, Ya. A. Kosenok, V. V. Vaskevich, O. I. Tyulenkova, V. E. Borisenko, N. S. Kovalchuk, A. N. Pyatlitski, S. V. Chumak","doi":"10.29235/1561-2430-2023-59-3-233-240","DOIUrl":"https://doi.org/10.29235/1561-2430-2023-59-3-233-240","url":null,"abstract":"We have herein developed a glass-forming composition and the related sol-gel technology for bonding monocrystalline silicon wafers to produce «silicon–insulator–silicon» structures. A possibility to fabricate defect-free glass-like bonding layers at the annealing temperature decreased to 1000–1100 °C is demonstrated. The composites obtained by the sol-gel method can be used in technological processes of formation of the solid compound of silicon wafers.","PeriodicalId":493733,"journal":{"name":"Vescì Nacyânalʹnaj akadèmìì navuk Belarusì","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135743934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the сontrollability, observability, and optimization of discrete nonstationary linear Volterra systems","authors":"A. I. Astrovskii, V. V. Goryachkin, M. P. Dymkov","doi":"10.29235/1561-2430-2023-59-3-213-223","DOIUrl":"https://doi.org/10.29235/1561-2430-2023-59-3-213-223","url":null,"abstract":"In this article, we study discrete nonstationary linear dynamic systems of Volterra type. An essential feature of such kind of systems is that their current states depend on the previous states of this system. The formula Cauchy, which gives us the solution of linear Volterra systems with the control inputs, is obtained. The necessary and sufficient conditions of the pointwise controllability, pointwise output controllability, and observability are proven. Also the linear-quadratic optimization problem for the nonstationary Volterra control systems is studied.","PeriodicalId":493733,"journal":{"name":"Vescì Nacyânalʹnaj akadèmìì navuk Belarusì","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135744189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On rational approximations of Poisson integrals on the interval by Fejer sums of Fourier – Chebyshev integral operators","authors":"P. G. Patseika, Ya. A. Rouba","doi":"10.29235/1561-2430-2023-59-3-183-200","DOIUrl":"https://doi.org/10.29235/1561-2430-2023-59-3-183-200","url":null,"abstract":"Approximations of the Fejér sums of the Fourier – Chebyshev rational integral operators with restrictions on numerical geometrically different poles are herein studied. The object of research is the class of functions defined by Poisson integrals on the segment [–1, 1]. Integral representations of approximations and upper estimates of uniform approximations are established. In the case when the boundary function has a power singularity on the segment [–1, 1], upper estimates of pointwise and uniform approximations are found, and the asymptotic representation of the majorant of uniform approximations is found. As a separate problem, approximations of Poisson integrals for two geometrically different poles of the approximating rational function are considered. In this case, the optimal values of the parameters at which the highest rate of uniform approximations by the studied method is achieved are found. If the function |x|s, s ∈ (0, 1], is approximated, then this rate is higher than the corresponding polynomial analogues. Consequently, asymptotic expressions of the exact upper bounds of the deviations of Fejer sums of polynomial Fourier – Chebyshev series on classes of Poisson integrals on a segment are obtained. Estimates of uniform approximations by Fejer sums of polynomial Fourier – Chebyshev series of functions given by Poisson integrals on a segment with a boundary function having a power singularity are also obtained.","PeriodicalId":493733,"journal":{"name":"Vescì Nacyânalʹnaj akadèmìì navuk Belarusì","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135901416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the calculation of functionals from the solution of the linear Skorohod SDE with first-order chaos in the coefficients","authors":"A. D. Egorov","doi":"10.29235/1561-2430-2023-59-3-201-212","DOIUrl":"https://doi.org/10.29235/1561-2430-2023-59-3-201-212","url":null,"abstract":"This article is devoted to the precise and approximate calculation of the mathematical expectation of non-linear functionals from the solution of the linear Skorohod equation with first-order chaos in the coefficients and the initial condition. In [1–4], approximate methods for calculating the mathematical expectation of functionals from solutions of the linear Skorohod stochastic differential equation with a random initial condition and deterministic coefficient functions were proposed and investigated. This paper considers the calculation of the mathematical expectation of nonlinear functionals from the solution to the linear Skorohod equation with first-order chaos in the coefficients and the initial condition. In this case, the solution is obtained in an analytical form [5]; however, it contains an unknown random parameter, determined as the solution of an auxiliary integral stochastic equation. In this paper we investigate the cases when the solution of this integral equation is found in an explicit form and then evaluate the moments and the mathematical expectations of some types of functional from the solution of the initial Skorohod equation. The construction of approximate formulas for calculating more general nonlinear functionals from the solution is considered. Numerical examples are given to illustrate the accuracy of the obtained formulas.","PeriodicalId":493733,"journal":{"name":"Vescì Nacyânalʹnaj akadèmìì navuk Belarusì","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135901418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PCR with hydrolysis probes for detection of fluoroquinolone resistance mutations in Mycobacterium tuberculosis","authors":"V. V. Slizen, L. K. Surkova, G. L. Gurevich","doi":"10.29235/1814-6023-2023-20-2-158-167","DOIUrl":"https://doi.org/10.29235/1814-6023-2023-20-2-158-167","url":null,"abstract":"Early diagnostics of resistance to fluoroquinolones facilitates early start of adequate therapy and increases the chance of a favorable outcome of the tuberculosis. Application of genetic methods permits to obtain within 1–2 days the results of Mycobacterium tuberculosis resistance detection to anti-tuberculosis drugs, unlike the classical methods requiring up to 1−2 month. The aim of the study is to develop a method for the M. tuberculosis identification and detection of point mutations in codons 90, 91, 94 of the gyrA gene associated with the resistance to fluoroquinolones. There were 88 cultures of mycobacteria studied: M. tuberculosis (n = 81), M. tuberculosis H37Rv, M. chelonae (n = 1), M. gordonae (n = 1), M. fortuitum (n = 1), and other three isolates of non-tuberculosis mycobacteria isolated from patients in the Republican Scientific and Practical Center for Pulmonology and Phthisiatry. The types of mutations in the gyrA gene were studied by the standard GenoTypeMTBDRsl method (HAIN, Germany), Sanger sequencing, and by the developed real-time PCR method. Based on the analysis of mutations in the gyrA gene in 78 isolates of M. tuberculosis, the dominant mutations were found to be mutations Asp94Gly and Ala90Val, which were identified in 21 and 27 isolates correspondingly: they accounted for 64 % of all mutations. M. tuberculosis also harbored mutations p.ASP94ALA and p.ASP94TYR/HIS in 6 (8.0 %) and 9 (12.0 %) isolates, respectively. One strain harbored a mutation at triplet 88 and one strain had a double mutation (p.ALA90VAL and p.ASP94GLY). The developed real-time PCR method demonstrated a high frequency of coincidence of results with the phenotypic determination of resistance to ofloxacin and the results testing by the standard GenoTypeMTBDRsl method and sequencing. The developed method is accomplished to identify M. tuberculosis, and discriminate mutations p.ALA90VAL, p.SER91PRO, p.ASP94ALA, p.ASP94TYR/HIS, p.ASP94GLY, p.ASP94ASN providing diagnostics of resistance to fluoroquinolones.","PeriodicalId":493733,"journal":{"name":"Vescì Nacyânalʹnaj akadèmìì navuk Belarusì","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135703159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}