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Bài thuyết trình An toàn và sức khỏe khi sử dụng bức xạ

Bài thuyết trình An toàn và sức khỏe khi sử dụng bức xạ tiến hành nghiên cứu khái quát về bức xạ; khái niệm và phân loại bức xạ; công dụng khi sử dụng bức xạ; tác hại của bức xạ; các quy định về an toàn và sức khỏe của bức xã.

12/29/2020 8:30:30 PM +00:00

A raman spectroscopy study of nano sized TiO2

In this report, we present the effect of size on the structure and Raman spectra of nano-sized TiO2 particles. The powder samples were prepared by the hydrothermal method. We used Raman spectroscopy to investigate the effect of size on structural properties of the samples.

12/29/2020 5:54:58 PM +00:00

The interface properties of two component Bose - Einstein condensates

The analytical expressions for the wave functions of two-component Bose-Einstein Condensates are derived by means of the Gross-Pitaevskii equations in linear approximation. Based on the Bernoulli equation the shape of the interface and the dispersion relations for both phonon and ripplonare studied.

12/29/2020 2:36:57 PM +00:00

Analytic expression of thermodynamic quantities for molecular cryocrystals of nitrogen type with fcc and hcp structures in harmonic, classical and anharmonic approximations

The analytic expressions of thermodynamic quantities such as the Helmholtz free energy, the internal energy, the entropy, the molar heat capacity at constant volume for molecular cryocrystals of N2 type with face-centered cubic (FCC) and hexagonal close-packed (HCP) structures in harmonic, classical and anharmonic approximations are obtained by combining the statistical moment method (SMM) and the self-consistent field method (SCFM).

12/29/2020 2:36:13 PM +00:00

Fuzzy function dependencies in fuzzy object oriented databases

This paper concerns to fuzzy dependencies of attributes on fuzzy object class. Base on the possibility distribution approach, we proposes the formal definition of fuzzy functional and multivalued dependencies on object class. The dependencies in this study allows a sound and complete set of inference rules.

12/29/2020 2:35:13 PM +00:00

Thermodynamic properties of some rare earth alloys

Thermodynamic properties of some rare-earth alloys have been studied using the statistical moment method (SMM) and analytic expressions of the Helmholtz free energy and thermodynamic properties of some rare-earth alloys have been obtained.

12/29/2020 2:30:57 PM +00:00

Novel rerults on the global exponential stability of cellular neural networks with variable coefficients and unbounded delays

In this article, we study cellular neural networks (CNNs) with time-varying coefficients, bounded and unbounded delays. By introducing a new Liapunov function to approach unbounded delays and using technique of Young inequality, we obtain some sufficient conditions which ensure global exponential stability of CNNs with unbounded delays and without assumption on boundness of active functions.

12/29/2020 2:29:25 PM +00:00

Preparation by wet chemical method and some of properties of ZnS and ZnS : Mn2 nano materials

Semiconductors nanoparticles have quantum size effects and non-linear optical characteristics as well as high quantum efficiency, making them next-generation materials that can be applied in various optoelectronic devices. Semiconductor nanoparticles have attracted much attention because of their novel electric and optical properties originating from surface and quantum confinement effects.

12/29/2020 2:26:37 PM +00:00

Nghiên cứu hoạt tính xúc tác của một số hỗn hợp oxit trên cơ sở CuO trong phản ứng oxi hóa m-xilen

. Mục đích của bài báo này là tìm hệ xúc tác thay thế xúc tác kim loại quý cho quá trình oxi hóa các hợp chất hữu cơ dễ bay hơi (VOC). Với ý tưởng tìm ra xúc tác oxit kim loại chuyển tiếp phù hợp nhất cho việc xử lí VOC, chúng tôi đã tổng hợp các xúc tác CuO, CuO-CeO2, CuO-Co2O3, CuO-Fe2O3 bằng phương pháp sol-gel xitric, sau đó tiến hành đặc trưng xúc tác bằng các phương pháp XRD, TPR-H2 và kiểm tra hoạt tính xúc tác cho phản ứng oxi hóa m-xilen.

12/29/2020 2:25:37 PM +00:00

On the multiplicity of multi graded fiber cones

This paper is divided into three sections. In Section 2, we give some results on weak- (FC)-sequences of modules and the analytic spread of ideals. Section 3 investigates the Krull dimension and the multiplicity of multi-graded fiber cones. The main result of this section is Theorem 3.3.

12/29/2020 2:25:00 PM +00:00

An approach to dark matter and dark energy

In this paper, we show an approach to the dark matter and dark energy. This approach does not demand dark energy with the anti-gravitational property. It also points out a lower limit of the average mass of the particles of cosmological energy (ordinary matter, dark matter and dark energy particles) m>54eV.

12/29/2020 2:24:34 PM +00:00

Quantum diffusion monte carlo method for low-dimentional systems

We will show that Schrodinger equations for low-dimensional systems can be solved by the method of quantum Diffusion Monte Carlo (DMC). The wave function and energy in a ground state are found for the two-dimensional harmonic oscillator, quantum wells, quantum wires and quantum dots. This is great approach for problems of low-dimensional systems. In this paper, the sign of the wave function is not treated.

12/29/2020 2:24:13 PM +00:00

Vận dụng một số kĩ thuật đánh giá tích cực cho môn học tư duy hệ thống nhằm đạt chuẩn đầu ra theo hướng tiếp cận CDIO tại trường Đại học Sư phạm Kĩ thuật thành phố Hồ Chí Minh

Bài viết này sẽ đề cập tới vấn đề vận dụng một số kĩ thuật đánh giá tích cực trong đánh giá kết quả học tập môn học Tư duy hệ thống nhằm đạt chuẩn đầu ra theo hướng tiếp cận CDIO đang được áp dụng tại trường ĐH Sư phạm Kĩ thuật Thành phố Hồ Chí Minh.

12/29/2020 2:24:07 PM +00:00

Ảnh hưởng của một số yếu tố đến nuôi cấy bao phấn cây lai F1 của một số cắp lúa lai

Phương pháp NCBP được áp dụng cho nhiều đối tượng trong đó phổ biến nhất là lúa, loài cây lương thực quan trọng nhất ở nước ta. Tuy nhiên, NCBP nói chung và NCBP lúa nói riêng đòi hỏi điều kiện nuôi cấy tương đối phức tạp. Trong báo cáo này tác giả trình bày một số kết quả về ảnh hưởng của một số yếu tố đến hiệu quá NCBP lúa ở cây lai F1 của một số cặp lai.

12/29/2020 2:24:00 PM +00:00

Optimal provisioning of optical networks with asymmetric nodes

In this paper, we propose an optimization model to establish the best ROADM switching connectivity to maximize the grade of service, for a given number of ports. We show that the grade of service can vary significantly, up to 30, depending on the switching connectivity.

12/29/2020 2:23:54 PM +00:00

Bác sĩ Zivagô của B.Paxternax và những suy ngẫm về nghệ thuật ngôn từ

B.Paxternax (1890-1960) không chỉ là nhà thơ, nhà văn mà còn là nhà mỹ học Nga xuất sắc. Những quan điểm mỹ học vượt trước thời đại của ông là một chủ đề rất quan trong trong tiểu thuyết Bác sĩ Zivago (Giải thưởng Noben văn học năm 1958). Mục đích chính của bài viết này là những giá trị mỹ học tiềm ẩn trong tiểu thuyết của ông.

12/29/2020 2:23:19 PM +00:00

The influence of SiO2 doped concentration, temperature and pressure on the microstructure of Al2O3(SiO2)x bulk model

This paper looks at the influence of SiO2-doped concentration, temperature and pressure on the microstructure of the Al2O3(SiO2)x (ASx) bulk model using the Molecular Dynamics (MD) method with a Born-Mayer pair interaction potential and periodic boundary conditions.

12/29/2020 2:22:52 PM +00:00

A feature representation method based on heterogeneous information network for android malware detection

The rapid growth in number, sophistication, and diversity of Android malware poses a great difficulty in extracting and analyzing features and behaviors. The traditional approach, which using only API calls and permissions to extract features, has no longer yielded meaningful results.

12/29/2020 2:22:33 PM +00:00

Thermodynamic properties of binary interstitial alloys with a bcc structure: Dependence on temperature and concentration of interstitial atoms

Thermodynamic quantities such as mean nearest neighbor distance, free energy, isothermal and adiabatic compressibilities, isothermal and adiabatic elastic modulus, thermal expansion coefficient, heat capacities at constant volume and constant pressure, and entropy of binary interstitial alloys with a body-centered cubic (BCC) structure with a very small concentration of interstitial atoms are derived using the statistical moment method.

12/29/2020 2:22:07 PM +00:00

Tán xạ e, e-→u,u-có sự tham gia của U-hạt khi xét tới sự phân cực trong mô hình siêu đối xứng

Trong bài báo này, chúng tôi nghiên cứu quá trình va chạm của các chùm e, e- tạo thành các chùm u,u- thông qua các hạt trung gian photon, Z boson, U-hạt và các hạt Higgs trung hòa có xét đến sự phân cực của chùm hạt e, e-. Kết quả cho thấy sự Ďóng góp của U- hạt vào tiết diện tán xạ là rất lớn, lớn hơn rất nhiều so với đóng góp của các hạt trung gian còn lại.

12/29/2020 2:22:00 PM +00:00

Tunable diode laser spectroscopy and line parameters of water vapor in the near infrared

In this study, we present the technique of tunable diode laser spectroscopy and the spectroscopic parameters of 13 lines of H2O in the 11980 -12260 cm−1 spectral region. Spectra were recorded at room temperature for a wide range of pressures (2 - 15 Torr for pure H2O and 50 - 760 Torr for H2O in air).

12/29/2020 2:21:53 PM +00:00

Pressure induced structural changes in liquid MgSiO3

The micro-structure of liquid MgSiO3 is studied using molecular dynamics simulation (MD) with Born-Mayer potential. Models consisting of 5000 atoms are constructed at 3500 K over a large pressure range (0 - 25 GPa). The local structure as well as network topology of liquid MgSiO3 is clarified through analyses based on molecular dynamics simulation data

12/29/2020 2:21:46 PM +00:00

Application of air quality index and inverse distance weighting for mapping the distribution of air pollution at several urban districts of Hanoi city

The air pollution level can be assessed using air quality index - AQI calculated from the concentration of some gases and particle matters which are measured at ambient air quality monitoring stations. The calculated AQI values are characterized by temporal continuity but spatial discontinuity.

12/29/2020 2:21:32 PM +00:00

Plasticity based interface model for failure modelling of unreinforced masonry under cyclic loading

In this work our objective is to understand the failure behaviour of unreinforced masonry under in-plane cyclic loading. For this purpose we proposed a plasticity based interface model consists of a single yield surface criteria which is a direct extension of Mohr–Coulomb criteria with a tension cut and compression cap and a back stress vector is introduced as a mixed hardening law variable in the adopted yield surface to capture the unloading/reloading behaviour of masonry under cyclic loading. A simplified micromechanical interface modelling approach is adopted to capture all the failure modes of masonry. The integration of the differential constitutive equation is done by using implicit Euler backward integration approach and the obtained non-linear set of equations are solved by a combined local/global Newton solver. The proposed constitutive model is implemented in ABAQUS by writing UMAT (user-defined subroutine) and the obtained numerical results are compared with experimental results available in the literature.

12/29/2020 1:59:51 PM +00:00

A simple size-dependent isogeometric approach for bending analysis of functionally graded microplates using the modified strain gradient elasticity theory

In this study, a simple size-dependent isogeometric approach for bending analysis of functionally graded (FG) microplates using the modified strain gradient theory (MSGT), simple first-order shear deformation theory (sFSDT) and isogeometric analysis is presented for the first time. The present approach reduces one variable when comparing with the original first-order shear deformation theory (FSDT) within five variables and only considers three material length scale parameters (MLSPs) to capture size effects. Effective material properties as Young’s modulus, Poisson’s ratio and density mass are computed by a rule of mixture.

12/29/2020 1:59:39 PM +00:00

A modified averaging operator with some applications

The paper presents a new approach to the conventional averaging in which the role of boundary values is considered in a more detailed way. It results in a new weighted local averaging operator (WLAO) taking into account the particular role of boundary values. A remarkable feature of WLAO is that this operator contains a parameter of boundary regulation p and depends on a local value h of the integration domain. By varying these two parameters one can regulate the obtained approximate solutions in order to get more accurate ones. It has been shown that the combination of WLAO with Galerkin method can lead to an effective approximate tool for the buckling problem of columns and for the frequency analysis of free vibration of strongly nonlinear systems.

12/29/2020 1:59:32 PM +00:00

The method of finite spheres in acoustic wave propagation through nonhomogeneous media: INF-SUP stability conditions

This paper the analysis and use of these conditions. Since the conditions involve norms of functionals in fractional Sobolev spaces, we derive ‘stronger’ conditions that are simpler in form. These new conditions pave the way for the inf-sup testing, a tool for assessing the stability of the discretized problems.

12/29/2020 1:59:16 PM +00:00

Size dependent of the effective conductivity of composite with imperfect interfaces

Based on the circle assemblage model, the effective properties of the inclusion with imperfect interface are derived. The equivalent inclusion is incorporated in the Fourier Transform algorithm to determine the effective conductivity of the composite with lowly conducting or highly conducting interface. The size effect is considered for both cases.

12/29/2020 1:58:44 PM +00:00

Structural, electronic and mechanical properties of few-layer porous nanosheet from spheroidal cage-like ZnO polymorph

Optimized geometries, formation energy, phonon spectra, electronic band structure, and elastic tensor calculation has ensured the energetically, dynamical and mechanical stability for the sheets. Furthermore, the theoretically found nanosheet series possess an intrinsic wide direct band gap preserving from wurtzite tetragonal-based bonding. This high symmetry wide bandgap semiconductor nanosheet series and their derivatives are expected to have broad applications in photocatalysis, and biomedicine.

12/29/2020 1:58:14 PM +00:00

Condensate density of a bose gas confined between two parallel plates in canonical ensemble within improved Hartree-fock approximation

By means of Cornwall-Jackiw-Tomboulis (CJT) effective action approach, the condensate density of a dilute Bose gas is investigated in the canonical ensemble. Our results show that the condensate density is proportional to a half-integer power law of the s-wave scattering length and distance between two plates. Apart from that, these quantities also depend on the particle number and area of each plate.

12/29/2020 1:58:08 PM +00:00