Tài liệu miễn phí Toán học
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Cosine transform on time scales
In this article, we construct and study the cosine (Tc) integral transform on the time scales Th. Some operator properties are obtained. Convolution for the (Tc) transform on the time scales and its application to solve the difference equations are considered.
12/29/2020 10:28:08 AM +00:00
Structural characteritics of iron oxide nanoparticles synthesized by CO-precipitation method in different conditions
This study aimed to investigate the structural characteristics of iron oxide nanoparticles (IONPs) prepared in different conditions. IONPs were synthesized as aqueous magnetic fluids by co-precipitation of ferrous and ferric salts, then analyzed by transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman scattering spectroscopy.
12/29/2020 10:20:36 AM +00:00
A study of the (ZrO2)n (n = 1/11) clusters by density functional theory
In this work, we calculate the formation energy, electronic structures, stabilities and Raman spectra for varying isomers of (ZrO2)n clusters. The total binding energy of the cluster (ZrO2)n indicates that energies of stabilization does not decrease monotonically with increasing size and the energies change very slow from n = 5.
12/29/2020 10:20:29 AM +00:00
Phase diagram of colloidal systems: A comparison of standard monte carlo simulations and virtual-move monte carlo simulations
In this work, we investigate the phase diagram of a three-dimensional Lennard-Jones (LJ) and square-well (SQW) system by means of both standard Monte Carlo simulation (SPMC) and “virtual-move” Monte Carlo simulations (VMMC). We find that the phase diagrams obtained by both SPMC and VMMC are very similar.
12/29/2020 10:20:22 AM +00:00
Elastic deformation of alloy AuSi with FCC structure under pressure
The theory of elastic deformation for binary interstitial alloy with FCC structure under pressure is builded by the statistical moment method. The elastic deformation of main metal is special case of elastic deformation for binary interstitial alloy. The theoretical results are applied to alloy AuSi. The numerical results for alloy AuSi are compared with the numerical results for main metal Au and experiments.
12/29/2020 10:20:16 AM +00:00
Study on nonlinear deformation of binary interstitial alloy AB with BCC structure under pressure
The analytic expressions of the free energy, the mean nearest neighbor distance between two atoms and the nonlinear deformation quantities such as the density of deformation energy, the maximum real stress and the limit of elastic deformation for interstitial alloy AB with BCC structure under pressure are derived from the statistical moment method. The nonlinear deformations of main metal A is special case of nonlinear deformation for interstitial alloy AB.
12/29/2020 10:20:10 AM +00:00
ELF-assembly of hard sphere droplet colloid mixture into quasicrystal
In this work, we investigate the phase diagram of a single-component system of colloidal particles and a binary mixture of hard-core droplets and colloids using means of molecular dynamics. For the former case, we found a variety of different crystal phases, in a good agreement with these observed in the simulation work (Engel et al, Nature Materials 14, 109–116 (2015)).
12/29/2020 10:20:02 AM +00:00
Casimir force on a single interacting bose Einstein condensate in the double-parabola approximation
The forces on a dilute single Bose-Einstein condensate confined between two parallel palates consist of two kinds, namely surface tension force and Casimir force. Within framework of double parabola approximation the surface tension force is investigated. The Casimir force is studied by quantum field theory in one-loop approximation. The total force is also obtained.
12/29/2020 10:19:54 AM +00:00
Hadron-quark phase transition of chiral nuclear matter to quark-gluon plasma at very high temperature
In this paper, the hadron-quark phase transition occurs after the chiral phase transition in the nuclear matter, that is so-called quarkyonic-like phase, in which the chiral symmetry is restored but the elementary excitation modes are nucleonic, appears just before deconfinement. In other words, there is the coexistence of hadrons and quarks as a mixed region.
12/29/2020 10:19:47 AM +00:00
Convexity properties for some general integral operators
For analitic functions f and g in the open unit disk U. In this paper we consider the classes N(B), K(B) and two integral operarors functions fn(f, g) and Jn(f, g), where g is a functions that the belongs to the family B(u, B). The main object of this paper is to obtain some properties in this class and and the order of convexity for two integral operators.
12/29/2020 10:19:35 AM +00:00
On the number of determining finite volume elements for 3D Navier-Stokes-Voigt equations
We give an upper bound on the number of determining finite volume elements for 3D Navier-Stokes-Voigt equations in bounded domains with periodic boundary conditions, which is estimated explicitly in terms of flow parameters, such as viscosity, smoothing length, forcing and domain size.
12/29/2020 10:19:29 AM +00:00
Singularities of parametric surfaces of bidegree (1, 2) in the particular cases
Parametric surfaces of bidegree (1,2) is described by at most two parameters, called moduli, by a change of coordinates. Its singular locus is generically a twisted cubic curve. In this article, we study all the particular cases and give normal forms of the parameterizations for each case. We give also the implicit equation and describe the singularity of the corresponding surface.
12/29/2020 10:19:23 AM +00:00
A simple unity theory for three types of polaritons (phonon polariton, exciton polariton and plasmon polariton) expanded model for surface polaritons
In this work, this theory is expanded for these three types of surface polaritons. We introduce an effective LT-splitting for surface plasmon polariton. Using this assumption, a new simple model for surface plasmon polariton with an effective LT–splitting was constructed.
12/29/2020 10:09:20 AM +00:00
Investigation of thermodynamic and mechanical properties of AlyGa1-yAs/GaAs systems by statistical moment method
In this paper, the moment method in statistical dynamics (SMM) is used to study the thermodynamic quantities of AlyGa1-yAs/GaAs systems taking into account the anharmonicity effects of lattice vibrations. The nearest neighbor distance, lattice parameter, isothermal bulk modulus, specific heats at the constant volume and pressure of AlyGa1-yAs/GaAs systems are calculated as functions of the temperature and concentration of Al by using the many-body potential.
12/29/2020 10:09:14 AM +00:00
Thermodynamic properties of binary interstitial alloy with FCC structure: Dependence on temperature and concentration of interstitial atoms
The theoretical results are applied to interstitial alloy AuSi. In the case when the concentration of interstitial atoms is equal to zero, we obtain the thermodynamic quantities of the main metal and the numerical results for alloy AuSi give the numerical results for Au.
12/29/2020 10:08:53 AM +00:00
Study on the melting of substitutional alloy AB with interstitial atom C and FCC structure under pressure
The obtained results allow us to determine the melting temperature of alloy ABC at zero pressure and under pressure. In limit cases, we obtain the melting theory of main metal A, substitutional alloy AB and interstitial alloy AC with FCC structure. The theoretical results are numerically applied for alloys AuCuSi and AgCuSi.
12/29/2020 10:08:46 AM +00:00
Phase transition in Z2xZ2 model based on the CJT formalism
A renormalization prescription is developed for CJT effective action in the double bubble approximation. It is shown that the triviality-related feature of the model does not show up. The phase transitions patterns are considered in detail for a specified set of model parameters.
12/29/2020 10:08:39 AM +00:00
A quantum phase transition in the bose-einstein condensates
Quantum phase transition and dynamical stability in Bose-Einstein condensates (BECs) are studied within the framework of the Cornwall-Jackiw-Tomboulis (CJT) effective action approach. The effective potential is found in the double-bubble diagram approximation. Numerical results show that in this approximation stability is strongly influenced by the chemical potential and the quantum phase transition is of second order.
12/29/2020 10:08:33 AM +00:00
Algebraic dependences of meromorphic mappings sharing moving hyperplanes without counting multiplicities
In this article, we will prove a algebraic dependences theorem for meromorphic mappings sharing moving hyperplanes with different multiple and a general condition on the intersections of the inverse images of these hyperplanes.
12/29/2020 10:08:26 AM +00:00
Regularity of ideals associated with a complete graph in two weights (2,1)
In this paper, we will determine regularity of ideals associated with a complete graph in two weight. The value of this function depends on the structure of an associated simplex graph.
12/29/2020 10:08:13 AM +00:00
Mano titanium dioxide coated on multi wall carbon nanotubes for photocatalytic application
Titanium dioxide (TiO2) coated on multi-walled carbon nanotubes (CNTs) was synthesized with CNTs and TiO2 using the grinded method. The XRS spectra include that of the obtained single-phase anatase sample. The UV-Vis diffuse reflectance spectra show that the composite material can absorb at a higher wavelength and the absorption covers the whole visible region.
12/29/2020 9:57:54 AM +00:00
Pressure dependent structural heterogeneity in calcium silicate glass
This work presents a molecular dynamics simulation (MDS) of CaSiO3 glass using Born–Mayer–Huggins potentials. The structural organization and structural phase transition under compression as well as network structure of CaSiO3 are clarified through analysis and visualization of molecular dynamics simulation data.
12/29/2020 9:57:47 AM +00:00
Existence and uniqueness of solutions of some general fuzzy partial hyperbolic functional differential equations
In this paper, we investigate the existence and uniqueness of fuzzy solution for a class of general hyperbolic equations with state-dependent delays. We will prove the well-posedness of problem doesn’t depend on the domain and boundary data as well as initial data. Our method is based on Banach fixed point theorem in completely new weighted metric space.
12/29/2020 9:57:40 AM +00:00
Cremona group functor and its lie algebra
For example, we still don’t know if it has the structure of an algebraic group of infinite dimension. In this paper, we will construct the Cremona group functor, calculate its Lie algebra and show that its Lie algebra is simple.
12/29/2020 9:51:44 AM +00:00
Aemimetal insulator phase transition in a GaSb/InAs heterostructure
In this study, the authors will show that a semimetal-insulator phase transition may take place in the GaSb/InAs heterostructures due to the exciton pairing between the electrons and holes in the system. In the heterostructure, the top of the valence band of the InAs layer is higher than the bottom of the conduction band of the GaSb layer.
12/29/2020 9:42:14 AM +00:00
Simultaneous spectrophotometric determination of Cu(II), Co(II), Ni(II) using 1-(2-pyridylazo)-2-naphthol (PAN) by chemometric method
In addition, PAN was a colored reagent and absorption at a wavelength near to the wavelength of maximum absorbance of PAN complexes with metal ions lead to the mutual overlap between the reagent and the complex spectrum.
12/29/2020 9:41:29 AM +00:00
Bài giảng Giải tích 1 – PGS.TS. Tô Văn Ban
Bài giảng Giải tích 1 – PGS.TS. Tô Văn Ban cung cấp kiến thức bao gồm giới hạn, liên tục; đạo hàm, vi phân; tích phân; chuỗi. Để nắm chi tiết kiến thức phục vụ cho học tập và nghiên cứu, mời các bạn cùng tham khảo bài giảng.
12/29/2020 9:19:58 AM +00:00
Bài giảng Cơ sở toán học – Bài 1: Thuật toán đánh giá và tiếp cận
Bài giảng Cơ sở toán học – Bài 1: Thuật toán đánh giá và tiếp cận cung cấp cho người học kiến thức về thuật toán; độ phức tạp thuật toán; tiếp cận giải quyết bài toán. Mời các bạn cùng tham khảo bài giảng để nắm chi tiết nội dung kiến thức.
12/29/2020 9:18:40 AM +00:00
Nghiên cứu sai lầm của học sinh khi giải bài toán chia hết và chia đa thức từ cách tiếp cận của “hợp đồng dạy học”
Trong bài viết này, chúng tôi sử dụng khái niệm “hợp đồng dạy học” được giới thiệu bởi Guy Brousseau vào năm 1980, như là một công cụ để nghiên cứu sai lầm của học sinh. Nghiên cứu này được thực hiện theo tiến trình: Phân tích sách giáo khoa và sách bài tập Toán 8, tập 1, từ đó đề xuất hai quy tắc của “hợp đồng dạy học” liên quan đến việc giải bài toán chia hết và bài toán chia đa thức.
12/29/2020 9:15:47 AM +00:00
Dạy học các tham số đo độ phân tán ở lớp 10 theo định hướng bồi dưỡng hiểu biết thống kê
Nội dung trình bày trong bài viết này nằm trong hướng nghiên cứu của chúng tôi về dạy học Thống kê nhằm mục tiêu phát triển hiểu biết thống kê cho học sinh. Khái niệm hiểu biết thống kê sẽ được làm rõ trong phần thứ nhất của bài viết.
12/29/2020 9:15:40 AM +00:00