## Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

*Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences*is peer-reviewed scientific journal that publishes original scientific articles. The series has been founded at the National University of Uzbekistan in 1997. The main goal of this scientific journal is to promote the development of education and research work among teachers, doctoral students and students in mathematics, physics, chemistry, biology, geology and geography.

# Recent Content

Nonlocal boundary value problem for a system of mixed type equations with a line of degeneration

Kudratillo Fayazov and Ikrombek Khajiev

Nonlocal problems for a fractional order mixed parabolic equation

Azizbek Mamanazarov

Some properties of A(z)-subharmonic functions

Shohruh Khursanov

The ψ-harmonic measure and its properties

Nurbek Narzillaev and Kobiljon Kuldoshev

Behavior and dynamics of the set of absolute nilpotent and idempotent elements of chain of evolution algebras depending on the time

Anvar Imomkulov

The Fokas' unified transformation method for Airy equation on simple open star graph

Zarifboy Sobirov and Mardonbek Eshimbetov

Complex diffusion Monte-Carlo method: test by the simulation of the 2D fermions

Bakhodir Abdullaev, Mirzayousuf Musakhanov, and Atsushi Nakamura

Analytic approach to ground state energy of charged anyon gas in strong magnetic field

Bakhodir Abdullaev, Ulrich Rössler, Chul-Hong Park, and M. Musakhanov

Intermolecular dynamics of condensed state: study of temperature effect on anisotropy relaxation by vibration spectroscopy

Bakhodir Eshchanov, Shavkat Otajonov, Jurat Gayipov, Dilafruz Xudoyberdiyeva, and Sarvarbek Qurbanbayev

Distribution of root-knot nematodes on agricultural plants, harm and their host plants

Shoira Saidova, Holisa Eshova, Guzal Mirzaliyeva, and Sayora Sadikova

Thermodynamics of complexation and membrane activity of crown ethers

Ulugbek Mirkhodjaev, Oleg Yarishkin, Umida Sharafutdinova, Uktam Toyirov, Nafisa Atamuratova, Anisa Tashmukhamedova, and Bekdjan Tashmukhamedov

Differentiation of membrane active crown ethers on the multilamellar layers

Ulugbek Mirkhodjaev, Oleg Yarishkin, Umida Sharafutdinova, Uktam Toyirov, Nafisa Atamuratova, Anisa Tashmukhamedova, and Bekdjan Tashmukhamedov

Self-aggregation of C_{60} particles in a volume of evaporating droplets on a flat surface

Urol Makhmanov, Abdulmutallib Kokhkharov, Sagdilla Bakhramov, and Donats Erts

Physico-chemical and adsorption properties of activated adsorbents obtained on the basis of wood stems

Rakhimjon Paygamov, Izzat Eshmetov, Shakhnoza Kuldasheva, Hamdam Akbarov, and Feruza Jurayeva

To the education of operational thinking in the higher mathematics courses of the higher technical school

Valentin Zharov and Arslan Mardanov

On the solvability of hypersingular equation of peridynamics

Shavkat Alimov and Shukhrat Sheraliev

Generalized metric spaces and hyperspaces

Ruzinazar Beshimov and Dilnora Safarova

Damped oscillatory integrals and Weierstrass polynomials

Azimbay Sadullaev, Isroil Ikromov, and Shaxriddin Muranov

Restoring the function set by integrals for the family of parabolas on the plane

Akram Begmatov and Alisher Ismoilov

Geometric properties of A-harmonic functions

Shokhrukh Khursanov

The method of potentials for the Airy equation of fractional order

Kamoliddin Rakhimov

The entrance times for circle maps with a break

Akhtam Dzhalilov and Javlon Karimov

On the new nonlinear properties of the nonlinear heat conductivity problem in nondivergence form

Mersaid Aripov and Maftuha Sayfullayeva

The symmetric form of a poroelasticity system in terms of velocities, stresses and pressure

Sayyora Tuychieva

Test statistics based on independence processes

Leyla Kakadjanova

Fractional differentiation of the Grunwald-Letnikov-Hadamard type and the difference of the fractional order with a multiplicative step

Mahmadiyor Yakhshiboev

On the application of multidimensional logarithmic residue to systems of non-algebraic equations

Barlikbay Prenov

Photocatalytic performance of V_{2}O_{5} nanoparticles incorporated TiO_{2} nanotubes as a visible-light active photoelectrodefor water splitting

Ulugbek Shaislamov, Kamil Mukimov, and Turgunali Akhmadjanov

Death line for radio pulsars in braneworlds

Djavlanbek Rayimbaev, Satimbay Palvanov, Maksud Umaraliyev, and Malika Khudoyberdiyeva

Fixing mobile desert sands: definition of water resistance, mechanical strength and mechanism of fixing

Shakhnoza Kuldasheva, I. L. Ahmadjonov, N. Z. Adizova, I. D. Eshmetov, and Kh. I. Akbarov

Sequential estimation by intervals of a fixed width of the asymptotic variance of rank estimates of the shift parameter

Gulnoza Rakhimova

Change in the physical and chemical properties of oil-contaminated soil in the steppe zone

Zafarjon Jabbarov, Tokhtasin Abdrakhmanov, Shavkat Akhmedov, Urol Nomozov, and Muqaddas Abdurahmonova

On the asymptotic behavior of branching processes with stationary immigration

Yakubjan Khusanbaev and Sadulla Sharipov

On negative eigenvalues of the discrete Schrödinger operator with non-local potential

Zahriddin Muminov and Shukhrat Lakaev

On the number of the discrete spectrum of two-particle discrete Schröodinger operators

Zahriddin Muminov, Utkir Kuljanov, and Shukhrat Alladustov

Choosing the structure of convolutional neural networks for face recognition

Kabul Khudaybergenov

Jump theorems for the Bochner-Martinelli integral in domains with a piecewise smooth boundary

Alexander Kytmanov, Davlatbay Dzhumabaev, Bayrambay Utemuratov, and Barlikbay Prenov

The effect of prebiotics on intestinal digestion of carbohydrates in lead intoxicated rats

Lubov S. Kuchkarova, Irodakhon I. Karimova, Gulchekhra T. Kudeshova, and Khasan Yu. Kayumov

A theoretical study an influence of oxygen group elements to rotational barrier of 2-(2'-pyridyl)-1,3,4-oxa(thia, selena and tellura) diazoles

Alisher Eshimbetov, Khamza Toshov, Inderpreet Kaur, and Alisher Khaitboev

Investigation of isomer ratios in the reactions (γ, *n*) and (*n*, 2*n*) on nuclei ^{76}Ge and ^{82}Se

Satimbay Palvanov and Turgunali Akhmadzhanov

Research of parabolic surface points in Galilean space

Abdullaaziz Artykbaev and Bekzod Sultanov

2-local derivations on Virasoro algebras

Shavkat Ayupov and Bakhtiyor Yusupov

Ganikhodjaev's conjecture on mean ergodicity of quadratic stochastic operators

Mansoor Saburov and Khikmat Saburov

Physico-chemical properties new nitrogen- and phosphorus containing ion exchange resine on the base of polyvinylchloride

Davron Bekchanov, Mukhtar Mukhamediev, and Dilfuza Gafurova

Strain effect on the electronic transport properties of carbyne

Gofur Eshonqulov, Golibjon Berdiyorov, and Hicham Hamoudi

Bordering conditions determination for nanocomposites special properties

Tokhir Rakhimov, Muhtor Mukhamediev, and Dilfuza Gafurova

Asymptotics of solutions and numerical simulation of the nonlinear heat conductivity problem with absorption and variable density

Mersaid Aripov and Askar Mukimov

Sarymsakov cubic stochastic matrices

Mansoor Saburov and Khikmat Saburov

Oscillatory integrals and Weierstrass polynomials

Azimbay Sadullaev and Isroil Ikromov

Test particle motion around brany black hole immersed in an external asymptotically uniform magnetic field

Djavlanbek Rayimbaev, Azamjon Rakhmatov, Satimbay Palvanov, and Ahror Mamadjanov

Periodic table of elements, Mendeleev's periodic table: history, achievements and problems

Boris Oksengendler, Kamil Mukimov, Renat Letfullin, Nigora Turaeva, Gulmurza Abdurakhmanov, and Shavkat Yuldashev

Convergence analysis of feedforward neural networks with backpropagation

Avazjon Marakhimov and Kabul Khudaybergenov

On the continuation of the Hartogs series with holomorphic coefficients

Takhir Tuychiev and Jurabay Tishabaev

Solvable Leibniz superalgebras whose nilradical is a Lie superalgebra of maximal nilindex

Abror Khudoyberdiyev, Manuel Ladra, and Khosiat Muratova

The waiting time and dynamic partitions

Akhtam Dzhalilov and Mukhriddin Khomidov

Topological properties of hyperspaces

Ruzinazar Beshimov and Dilnora Safarova

On a control problem associated with fast heating of a thin rod

Shavkat Alimov and Farrukh Dekhkonov

Electron exchange between impurity centers of tin in PbS and PbSe

S. Zaynabiddinov and K. Bobokhujaev

Analysis of clusterization of *C*_{70} molecules in benzene solutions prepared by various methods

U. Makhmanov, O. Ismailova, A. Kokhkharov, and S. Bakhramov

Ill-posed boundary value problem for operator-differential equation of fourth order

Kudratillo Fayazov, Ikrom Khajiev, and Z. Fayazova

Electronic specific-heat anomalies in high-*T _{c}* cuprates

S. Dzhumanov, E. Karimboev, and B. Yavidov

Translation-invariant Gibbs measures of a model on Cayley tree

Golibjon Botirov

The extent of destruction of landscapes in the Tashkent region

Shavkat Sharipov, Kamoliddin Khakimov, and Davronbek Boymurodov

The optimal risk of estimator of conditional distribution function in a model of heteroscedastic regression with weakly dependent observations

Farkhad Abdikalikov and Laura Reymova

Amidoalkylation of aromatic compounds

Mukhabbat Yuldasheva, Khurshida Turaeva, and Tursunali Kholiqov

Thermal evolution modification due to radio-wave production inside rotating magnetized NS

Pulat Tadjimuratov

Formation of the database in the history of development of geodesy and cartography science (an example of Medieval East)

Eshkobul Safarov, Sunnatilla Uvrayimov, and Kuatbay Bekanov

Variability, inheritance of fiber length in 4-5 specific and backcross hybrids, tolerance of cotton hybrids to bollworm in depending of the level of gossypol

Sayfulla Boboyev, Fakhriddin Kushanov, Ikrom Amanturdiev, and Gulnoza Akhmedjanova

Ecological-taxonomical analysis of collembolans of the northeast of Uzbekistan

Matnazar Rakhimov, Zulkhumor Elmuratova, and Dilfuza Majidova

Extraction conductometric determination of scandium and thorium in kaolins

Nigora Kutlimurotova, Zulayho Smanova, Habibulla Tojimuhamedov, Zuhra Yaxshiyeva, and Jasur Tursunqulov

Neuro-fuzzy identification of nonlinear dependencies

Avazjon Marakhimov and Kabul Khudaybergenov

Some cardinal and topological properties of the *n*-permutation degree of a topological spaces and locally *τ*-density of hyperspaces

Farkhod Mukhamadiev

Carleman's formula for the matrix upper half-plane

Gulmirza Khudayberganov and Zokirbek Matyakubov

On the manifolds of positive curvature

Jasurbek Aslonov

Using an a priori estimate for constructing difference schemes for quasi-linear hyperbolic systems

Rakhmatillo Aloev and Mirzoali Khudayberganov