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Abstract: Liquid Na2O-4SiO2 has been constructed by molecular dynamics simulation at 1873 K, ambient pressure with periodic boundary conditions. To clarify the local environment of atoms, we apply the oxygen simplex (OS) which is characterized by the size, forming oxygen atom types and the number of sodium atoms located inside the OS. The simula...
8 trang | Chia sẻ: thanhle95 | Ngày: 13/07/2021 | Lượt xem: 286 | Lượt tải: 0
Abstract: Molecular dynamics simulation of sodium-silicate has been carried out to investigate the microstructural transformation and diffusion mechanism. The microstructure of sodium silicate is studied by the pair radial distribution function, distribution of SiOx (x=4,5,6), OSiy (y=2,3) basic unit, bond angle distribution. The simulation resu...
10 trang | Chia sẻ: thanhle95 | Ngày: 13/07/2021 | Lượt xem: 330 | Lượt tải: 0
Abstract: We report a facile process to fabricate cuprous thin films by thermal oxidation of copper substrates. Structure and phase identification were studied by X-ray diffraction measurement and Raman spectroscopy. Scanning electron microscopy was utilized to study surface morphology of the as-fabricated thin films and optical properties of th...
6 trang | Chia sẻ: thanhle95 | Ngày: 13/07/2021 | Lượt xem: 317 | Lượt tải: 0
1. Introduction In recent decades, there has been an increasing attraction in synthesis and studies of structural and physical properties of heavy metal oxide glasses due to their diversity applications in optical field [1- 3]. Among these glasses, tellurite glasses are technologically and scientifically important due to their outstanding prope...
8 trang | Chia sẻ: thanhle95 | Ngày: 13/07/2021 | Lượt xem: 374 | Lượt tải: 0
Abstract: In this work, we use molecular dynamic (MD) simulation to study the structure transition and crystallization of amorphous silica (SiO2) under compression. The structural evolution of amorphous SiO2 is explained through radial distribution function, coordination number distribution, bond angle distribution and visualization. Simulation ...
10 trang | Chia sẻ: thanhle95 | Ngày: 13/07/2021 | Lượt xem: 356 | Lượt tải: 0
Tóm tắt: Dạy học toán gắn với thực tiễn đang là một yêu cầu, một xu hướng trong dạy học Toán ở trường phổ thông của Việt Nam. Những luận giải về vấn đề “thực tiễn” và việc khai thác các “nhiệm vụ thực tiễn” trong dạy học môn Toán hiện còn nhiều điều chưa thực sự rõ ràng. Nghiên cứu này góp phần đưa ra những quan điểm về “nhiệm vụ thực tiễn” và v...
13 trang | Chia sẻ: thanhle95 | Ngày: 13/07/2021 | Lượt xem: 324 | Lượt tải: 0
Abstract: This paper studies the structure of the Mullite system (3Al2O3.2SiO2) by Molecular Dynamics simulation (MDs) using the Born–Mayer–Huggins pair interaction and periodic boundary conditions. The simulation was performed with model of 5250 atoms at different pressure and at 3500 K temperature. The structural properties of the system were ...
7 trang | Chia sẻ: thanhle95 | Ngày: 13/07/2021 | Lượt xem: 316 | Lượt tải: 0
Abstract: This paper investigates how PbS coating layers influence the characteristics of GaAs single junction solar cells through I-V characteristic measurements, optical reflectance spectra, and quantum efficiencies. To determine the expected influence, PbS quantum dots were coated on the surface of single junction GaAs solar cells by a drop c...
6 trang | Chia sẻ: thanhle95 | Ngày: 13/07/2021 | Lượt xem: 333 | Lượt tải: 0
Abstract: Dy3+doped alumino boro-tellurite (ABT) glasses xB2O3+(80-x)TeO2+10Al2O3+10CaO+ 0.5Dy2O3 (where x = 35; 45 and 55) have been prepared by melting method. Their optical properties were studied through absorption, luminescence spectra and decay time measurements. Judd-Ofelt (JO) intensity parameters (Ωλ, λ = 2, 4 and 6) were determined usi...
7 trang | Chia sẻ: thanhle95 | Ngày: 13/07/2021 | Lượt xem: 358 | Lượt tải: 0
Abstract: In this study, high-Tc superconducting polycrystalline Bi-2223 undoped sample (A0) and 5wt.% Ag-doped sample (A5) were prepared by solid-state reaction method at 8550C with sintering time of 8 days. The X-ray powder diffraction (XRD) results show that the major phase of these samples was Bi-2223. The volume ratio of Bi-2223 phase incre...
11 trang | Chia sẻ: thanhle95 | Ngày: 13/07/2021 | Lượt xem: 326 | Lượt tải: 0