• Khảo sát một số đặc trưng cơ bản của laser bán dẫn công suất cao ở chế độ xung ngắnKhảo sát một số đặc trưng cơ bản của laser bán dẫn công suất cao ở chế độ xung ngắn

    TÓM TẮT Laser là một trong hai phát minh lớn của thế kỉ XX, tạo tiền đề để phát triển ngành quang phổ học và là cơ sở cho rất nhiều ứng dụng thực tiễn. Hiện nay laser bán dẫn công suất cao đang được nghiên cứu chế tạo và ứng dụng phổ biến. Trong nghiên cứu này chúng tôi sử dụng máy phát xung ngắn, dòng lớn để nuôi laser và các hệ thiết bị đươ...

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  • Extensive air showers in HanoiExtensive air showers in Hanoi

    I. INTRODUCTION VATLY is a cosmic ray laboratory located in Ha Noi and operated in close association with the Pierre Auger Observatory (PAO) in Argentina [1]. In addition to contributions to the analysis of PAO data, VATLY performs measurements of its own, using detectors installed on the roof of the laboratory [2]. Among these is a replica of a...

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  • Entanglement of a scattered single photon and an excitonEntanglement of a scattered single photon and an exciton

    I. INTRODUCTION Entanglement with continuous variable attracts many attentions for its fundamental importance in quantum nonlocality [1] and quantum information science and technology [2]. As a physical realization, the continuous momentum entanglement between atom and photon has been extensively studied in the recent years [3–6]. In the proces...

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  • Electrical and optical properties of the hybrid TiO2 nanocrystals - MEH-PPV thin filmsElectrical and optical properties of the hybrid TiO2 nanocrystals - MEH-PPV thin films

    Abstract. Recently, the conjugated polymer – inorganic nanocomposites have been increasingly studied because of their enhanced optical and electronic properties as well as their potential application in developing optoelectronic devices. In this study nanocomposite materials thin films based on poly [2-methoxy-5-(2’-ethyl-hexyloxy)-1,4-phenylene ...

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  • Efficient generation of coherent stokes field in hydrogen gas-filled hollow core photonic crystal fibresEfficient generation of coherent stokes field in hydrogen gas-filled hollow core photonic crystal fibres

    Abstract. We study the coherent Stokes generation in a transient stimulated Raman scattering regime by Hydrogen gas-filled hollow-core photonic crystal fibres configuration. The temporal and spatial evolution of the pump and Stokes field envelopes as well as the coherence and population inversion are numerically calculated. The Stokes generation...

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  • Effect of spontaneous polarization charges on the electron mobility in ZnO surface quantum wellsEffect of spontaneous polarization charges on the electron mobility in ZnO surface quantum wells

    Abstract. We present a theoretical study of the effect due to spontaneous polarization of ZnO on the low-temperature mobility of the two-dimensional electron gas (2DEG) in a ZnO surface quantum well (SFQW). We proved that for the O-polar face this causes an attraction of electrons by the positive charges bound on the surface, while for the Zn-po...

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  • Effect of sm and mn co-Doping on the crystal structure and magnetic properties of BiFeO3 polycrystalline ceramicsEffect of sm and mn co-Doping on the crystal structure and magnetic properties of BiFeO3 polycrystalline ceramics

    Abstract. The crystal structure, phonon vibration, microstructure, and magnetic properties have been investigated in multiferroics Bi0:9Sm0:1Fe1−xMnxO3 for x = 0:02 – 0:1. The structural analysis by XRD and Rietveld refinement suggests that Mn doping compounds crystallize in the polar R3c rhombohedral symmetry (isostructural with BiFeO3). Raman a...

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  • Effect of pre-alloy composition on the content of ferromagnetic phase of MnBi melt spun ribbonsEffect of pre-alloy composition on the content of ferromagnetic phase of MnBi melt spun ribbons

    Abstract. The rare-earth-free hard magnetic material MnBi is potential for permanent magnet high-temperature applications with the ferromagnetic phase formed at low temperature (noted as a Low Temperature Phase – LTP). Up to now, the MnBi powders with high LTP content and coercivity have usually been prepared using the melt-spinning technique. H...

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  • Effect of polypyrrole on the electrical, dielectric and mechanical properties of waterborne epoxy coatingsEffect of polypyrrole on the electrical, dielectric and mechanical properties of waterborne epoxy coatings

    Abstract. In this context, dissipative composite based on waterborne epoxy system and polypyrrole (PPy) was investigated. PPy was synthesized by chemical oxidation polymerization. Its morphology and chemical structure were confirmed by using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Th...

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  • Effect of graphene-gold nanocomposites on the photocatalytic activity of TiO2Effect of graphene-gold nanocomposites on the photocatalytic activity of TiO2

    Abstract. The synthesis of graphene (Gr) - gold (Au) nanoparticle (NP) composite was achieved using continuous ultraviolet wave exposure. The functional groups were investigated with FTIR spectra. From the Raman spectra, D-band and G-band of Gr were identified. As a result, the uniform deposition of nanometer-sized Au NPs on the Gr sheets was obs...

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