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Phương pháp dạy và học tích cực trong môn Vật lí - GS. Trần Bá Hoành
Nội dung của ebook Áp dụng dạy và học tích cực trong môn Vật lí gồm có 3 phần giúp các bạn nắm được Lí luận chung về dạy và học tích cực; kế hoạch bài học minh họa dạy và học tích cực trong môn Văn học. Mời các bạn cùng tham khảo!
4/9/2023 12:43:25 PM +00:00
Ảnh hưởng của hệ kết hợp cấu trúc 1D và 2D của nanocacbon đến tính chất nhiệt lớp phủ Epoxy
Bài viết Ảnh hưởng của hệ kết hợp cấu trúc 1D và 2D của nanocacbon đến tính chất nhiệt lớp phủ Epoxy trình bày kết quả khảo sát ảnh hưởng của các cấu trúc khác nhau 1D và 2D của Nanocacbon vật liệu đến các đặc trưng nhiệt của màng phủ nhựa Epoxy.
4/9/2023 12:11:18 PM +00:00
Applying the permissive overreaching transfer trip of sel 311L distance relay to protect the transmission line
This paper presents the coordination of Permissive Over-Reaching Transfer Trip (POTT) interlock function of SEL 311L relay for power transmission lines to reduce the fault clearing time compared to the traditional calculation method.
4/9/2023 11:54:55 AM +00:00
Đánh giá năng lực hợp tác trong dạy học chương “Động lực học chất điểm” vật lý 10 trung học phổ thông
Bài viết Đánh giá năng lực hợp tác trong dạy học chương “Động lực học chất điểm” vật lý 10 trung học phổ thông đề xuất phương pháp đánh giá NLHT thông qua việc xây dựng bảng các tiêu chí đánh giá NLHT, đồng thời, thiết kế một số bảng hỏi, bảng kiểm như là công cụ đánh giá và thực nghiệm đánh giá NLHT trên 38 học sinh lớp 10 Trường trung học phổ thông A Lưới, huyện A Lưới, tỉnh Thừa Thiên Huế, năm học 2019-2020.
4/9/2023 11:51:58 AM +00:00
Phương pháp Discontinuous galerkin trong tính toán mô phỏng dòng khí loãng tốc độ cao
Bài viết Phương pháp Discontinuous galerkin trong tính toán mô phỏng dòng khí loãng tốc độ cao trình bày phương trình Navier-Stokes-Fourier mở rộng xem xét đến quá trình khuếch tán khối lượng; Phương pháp Discontinuous Galerkin cho phương trình N-S-F mở rộng.
4/9/2023 11:47:56 AM +00:00
Động lực học và các đặc tính dao động của hệ con lắc Furuta
Bài viết Động lực học và các đặc tính dao động của hệ con lắc Furuta trình bày chi tiết cách thiết lập phương trình động lực học của con lắc Furuta dựa trên các phương trình chuyển động Euler-Lagrange. Chương trình mô phỏng điều khiển và đặc tính chuyển động của các khâu trong con lắc Furuta sẽ được xây dựng trong ứng dụng Matlab.
4/9/2023 11:47:16 AM +00:00
Calculation of thermodynamic quantities of F.C.C and B.C.C metals using eam potentials
The moment method in the statistical dynamics is used to study the thermodynamic properties of metals taking into account the anharmonicity effects of the lattice vibrations. The effective pair potentials work well for the calculations of metals. For obtaining better agreement of the thermodynamic quantities of metals like Nb, the many body potentials derived from the microscopic electronic theory are used. The theoretical calculations of the thermodynamic properties are in good agreement with the corresponding experimental results.
4/9/2023 11:35:42 AM +00:00
High temperature symmetry nonrestoration and inverse symmetry breaking in the CornwallJackiw-Tomboulis formalism
The work High temperature symmetry nonrestoration and inverse symmetry breaking in the CornwallJackiw-Tomboulis formalism uses the finite temperature CJT effective action to shed new light on the Z2 x Z2 model in connection with the domain wall and other problems. Section II is dedicated to the calculation and normalization of the CJT effective action and Sec. III to the study of high temperature SNR and ISB. The results are discussed in Sec. IV where some conclusions are spelled out.
4/9/2023 11:34:51 AM +00:00
Composition of a Pyrolytic oil from Cupressus funebris Endl. of Vietnamese origin
The aim of the study Composition of a Pyrolytic oil from Cupressus funebris Endl. of Vietnamese origin was to determine the chemical composition of the pyrolytic oil extracted from C. funebris, produced in Vietnam, and to compare it with a commercial sample of Chinese cedarwood oil.
4/9/2023 11:34:00 AM +00:00
Study of Self-Diffusion in Silicon at High Pressure
The present paper is organized as follows: In §2, the theory of self-diffusion in semiconductors is described, and the relationship between pressure and volume for silicon is studied in §3. The numerical calculations for self-diffusion in silicon and the related discussions are provided in §4. Finally, §5 summarizes the present study.
4/9/2023 11:33:20 AM +00:00
Ohmic currents and predecoupling magnetism
Ohmic currents induced prior to decoupling are investigated in a standard transport model accounting both for the expansion of the background geometry as well as of its relativistic inhomogeneities. The relative balance of the Ohmic electric fields in comparison with the Hall and thermoelectric contributions is specifically addressed. The impact of the Ohmic currents on the evolution of curvature perturbations is discussed numerically and it is shown to depend explicitly upon the evolution of the conductivity.
4/9/2023 11:31:18 AM +00:00
Analysis of white dwarfs with strange-matter cores
In this paper, The authors expand on a previous study [33] aimed at identifying nearby candidate white dwarfs with strange-matter cores. The authors review the evidence for two populations of white dwarfs, one of which is more compact. The authors present an updated list of nearby stars with best determined masses and radii which are consistent with the existence of a strange-matter core, propose some observational tests of this hypothesis.
4/9/2023 11:30:38 AM +00:00
A Raman Spectroscopy Study of Disorder and Local Vibrational Modes in \({\rm{L}}{{\rm{a}}_{{\rm{0:7}}}}{\rm{S}}{{\rm{r}}_{{\rm{0:3}}}}{\rm{M}}{{\rm{n}}_{{\rm{1 - x}}}}{{\rm{M}}_{\rm{x}}}{{\rm{O}}_{\rm{3}}}\) (M=Fe, Co)
In the paper A Raman Spectroscopy Study of Disorder and Local Vibrational Modes in \({\rm{L}}{{\rm{a}}_{{\rm{0:7}}}}{\rm{S}}{{\rm{r}}_{{\rm{0:3}}}}{\rm{M}}{{\rm{n}}_{{\rm{1 - x}}}}{{\rm{M}}_{\rm{x}}}{{\rm{O}}_{\rm{3}}}\) (M=Fe, Co), the authors present results of Raman scattering and X-ray diraction studies of \({\rm{L}}{{\rm{a}}_{{\rm{0:7}}}}{\rm{S}}{{\rm{r}}_{{\rm{0:3}}}}{\rm{M}}{{\rm{n}}_{{\rm{1 - x}}}}{{\rm{M}}_{\rm{x}}}{{\rm{O}}_{\rm{3}}}\) (M=Fe, Co) manganites. Some Mn atoms were replaced by Fe and Co with x in the range of 0.0 { 0.75. XRD analysis of these samples indicates a change in the cell parameters with doping content. This research main focus is the Raman peak at high frequency \({\rm{( > 630 c}}{{\rm{m}}^{{\rm{ - 1}}}}{\rm{ )}}\), which is somewhat controversial. The Raman spectra exhibit an additional high-frequency mode attributed to a local breathing vibration of the oxygen surrounding the substituent ion.
4/9/2023 11:30:17 AM +00:00
Effects of crumb rubber content and curing time on the properties of asphalt concrete and stone mastic asphalt using dry process
Research objective of the project Effects of crumb rubber content and curing time on the properties of asphalt concrete and stone mastic asphalt using dry process evaluating the impact of relative fine CR (0-2.36 mm) modification and short-term ageing, determining the optimal percentage of CR and the effective absorption time in the range of 0- 5h for the optimal use of CR in asphalt mixtures demonstrating the possibility of introducing relative fine CR (0-2.36 mm) as a modifier into dense-graded AC using dry process.
4/9/2023 10:27:10 AM +00:00
Nghiên cứu sự ảnh hưởng của các tham số cấu trúc tới cộng hưởng điện-từ của vật liệu THz Metamaterial không phân cực
Bài viết Nghiên cứu sự ảnh hưởng của các tham số cấu trúc tới cộng hưởng điện-từ của vật liệu THz Metamaterial không phân cực nghiên cứu một cấu trúc đơn giản không phân cực có khả năng tạo cộng hưởng điện và cộng hưởng từ ở vùng THz. Bản chất cộng hưởng điện và từ cũng như sự phụ thuộc của các cộng hưởng này vào tham số hình học của cấu trúc được tập trung làm rõ. Kết quả mô phỏng và tính toán lý thuyết bằng mô hình mạch tương đương cũng được so sánh.
4/9/2023 10:15:39 AM +00:00
Mô hình hóa ứng xử cơ học của vật liệu bê tông nhựa sử dụng tiêu chuẩn dẻo Drucker-Prager và mô hình đàn hồi-dẻo-nhớt của Perzyna
Bài viết Mô hình hóa ứng xử cơ học của vật liệu bê tông nhựa sử dụng tiêu chuẩn dẻo Drucker-Prager và mô hình đàn hồi-dẻo-nhớt của Perzyna trình bày một qui luật ứng xử của vật liệu bê tông nhựa khi chịu tác dụng trùng phục của tải trọng xe cộ sử dụng tiêu chuẩn dẻo Drucker-Prager và mô hình đàn hồi–dẻo–nhớt Perzyna trong khuôn khổ chuyển vị và biến dạng lớn. Phương pháp “return mapping” được sử dụng để giải số các phương trình của mô hình và phương pháp phần tử hữu hạn phi tuyến được sử dụng để rời rạc hóa bài toán cơ học.
4/9/2023 10:15:09 AM +00:00
Global exponential stability of switched neutral systems with time-varying delays
The paper Global exponential stability of switched neutral systems with time-varying delays deals with the problem of global exponential stability for a class of switched neutral systems with time-varying delays. Based on improved Lyapunov-Krasovskii functional method combined with the Leibniz-Newton formula, linear matrix inequalities (LMIs) conditions are proposed for the exponential stability of the considered systems under arbitrary switching signal. A numerical example showing the effectiveness of our conditions is given.
4/9/2023 8:03:16 AM +00:00
Influence of the Particle Size on the Microstructure and the Curie Temperature (TC) of Nano-Iron Particles Model
The paper Influence of the Particle Size on the Microstructure and the Curie Temperature (TC) of Nano-Iron Particles Model studies the influence of the particle size (with the chosen sizes 2.122 nm; 2.49 nm; 2.884 nm; 3.128 nm; 3.254 nm; 4.07 nm; 4.68 nm; 4.978 nm; 5.3 nm; 6.602 nm; 7.774 nm; 8.392 nm) on the microstructure and the Curie temperature (Tc) of nano-iron particles model.
4/9/2023 8:02:43 AM +00:00
Constraints on preinflation fluctuations in a nearly flat open ΛCDM cosmology
In this paper, therefore, we explore the possibility that the universe is slightly open with Ω0 ≈ 0.994. In this case a glimpse of preinflation fluctuations could just now be entering the horizon before the universe becomes totally dark-energy dominated and flat. Our goal, therefore, is to determine what constraints might be placed on inhomogeneities and curvature content in the preinflation universe based upon current cosmological observations.
4/9/2023 8:01:52 AM +00:00
Origin and evolution of structure for galaxies in the local group
The paper Origin and evolution of structure for galaxies in the local group summarizes a review of recent attempts to reconstruct this complex evolution. We compare simulated properties with various observed properties of the Local Group. Among the generic features of simulated systems is the tendency for galactic halos to form within the dark matter filaments that define a supergalactic plane. Gravitational interaction along this structure leads to a streaming flow toward the two dominant galaxies in the cluster. We analyze this alignment and streaming flow and compare with the observed properties of Local-Group galaxies. Our comparison with Local Group properties suggests that some dwarf galaxies in the Local Group are part of a local streaming flow.
4/9/2023 8:01:41 AM +00:00
Constraints on pre-inflation cosmology and dark flow
In this work (Mathews et al., 2014a) we consider that the present universe is slightly open, i.e. ⌦0 0.994 at the 95% confidence level. In this case, any curvature that existed before inflation could now be visible on the horizon. Such pre-inflation fluctuations in the inflaton field could appear as a cosmic dark (or bulk) flow cosmological flow. We summarize an analytic model (KurkiSuonio et al., 1991; Mathews et al., 2014a) for an open cosmology with an adiabatic planar inhomogeneity of wavelength less than the initial Hubble scale.
4/9/2023 8:01:33 AM +00:00
Aggregate indices method in soil quality evaluation using the relative soil quality index
The paper Aggregate indices method in soil quality evaluation using the relative soil quality index presents a new approach to assess the soil quality by aggregate indices using the Relative Soil Quality Index (RSQI) proposed by Ho Ngoc Pham. RSQI is integrated from the individual indices into a simple formula for overall assessment of the soil quality. RSQI is different from other approaches. Particularly, the individual indices and the weighting factors of Pham are calculated from the analytical laboratory data and the environmental standards, respectively, and not self-regulated as in methods of some other authors.
4/9/2023 8:01:11 AM +00:00
Low resistivity molybdenum thin film towards the back contact of dye-sensitized solar cell
This paper reports the optimization of the molybdenum thin film electrode as the back contact of dye-sensitized solar cell (DSSC). The molybdenum thin film was grown on the glass substrate by direct current sputtering techniques of which the sputtering power was 150 W at 18 sccm flow rate of Ar. At such sputtering parameters, the Mo film can reach the lowest resistivity of 1.28E−6 cm at 400 nm thick. And the reflection of Mo membrane was 82%. This value is considered as a very good result for preparation of the back contact of DSSC.
4/9/2023 8:00:56 AM +00:00
Influence of shell thickness on thermal stability of bimetallic Al–Pd nanoparticles
Aluminum-based bimetallic core–shell nanoparticles have shown promising applications in civil and defense industries. This study addresses the thermal stability of aluminum–palladium (Al–Pd) core/shell nanoparticles with a varying shell thickness of 5, 6, and 7 A˚ , respectively. The classic molecular dynamics (MD) simulations are performed in order to investigate the effects of the shell thickness on the ignition mechanism and subsequent energetic processes of these nanoparticles.
4/9/2023 8:00:31 AM +00:00
Subextension of plurisubharmonic functions without changing the Monge–Ampère measures and applications
The aim of the paper Subextension of plurisubharmonic functions without changing the Monge–Ampère measures and applications is to investigate subextensions with boundary values of certain plurisubharmonic functions without changing the Monge–Ampère measures.
4/9/2023 7:59:35 AM +00:00
Mott transition in the dynamic Hubbard model within slave boson mean-field approach
In the paper Mott transition in the dynamic Hubbard model within slave boson mean-field approach, the influences of the dynamics of the auxiliary boson field on the Mott transition are investigated. At finite boson frequency, the Mott-type features of the Hubbard model is found to be enhanced by increasing the pseudospin coupling parameter g.
4/9/2023 7:59:14 AM +00:00
Annealing study of amorphous bulk and nanoparticle iron using molecular dynamics simulation
In particular, the system undergoes three stages. At first stage the relaxation proceeds slowly so that the energy of system slightly decreases and the samples structure remains amorphous. Within second stage a structural transformation occurs which significantly changes PRDF and DCN for the relatively short time. The energy of the system is dropped considerably and the amorphous structure transforms into the crystalline. Finally, the crystalline sample undergoes the slow relaxation which reduces the energy of system and eliminates structural defects in crystal lattices.
4/9/2023 7:57:12 AM +00:00
Existence and smoothness of solutions to second initial boundary value problems for Schrodinger systems in cylinders with non-smooth bases
In this paper, we consider the second initial boundary value problem for strongly general Schr¨odinger systems in both the finite and the infinite cylinders QT , 0 < T ≤ +∞, with non-smooth base Ω. Some results on the existence, uniqueness and smoothness with respect to time variable of generalized solution of this problem are given.
4/9/2023 7:55:01 AM +00:00
Some properties of SU(2) Yang-Mills Theory connecting with φ4 Theory
In this paper we consider some properties of the SU(2) Yang-Mills theory connecting with scalar φ4 theory. In the case when scalar field φ is time independent, we find explicit solution to equation of motion for corresponding φ4 theory. The spartial component of the SU(2) Yang-Mills potential corresponding with this solution is like potential of point magnetic monopole.
4/9/2023 7:54:08 AM +00:00
Ebook University physics (13th): Part 1
Ebook University physics (13th): Part 1 presents the following content: Units, Physical Quantities, and Vectors; Motion Along a Straight Line; Motion in Two or Three Dimensions; Newton’s Laws of Motion; Applying Newton’s Laws; Work and Kinetic Energy; Potential Energy and Energy Conservation; Momentum, Impulse, and Collisions; Rotation of Rigid Bodies;...
4/9/2023 7:47:58 AM +00:00