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  Subjects -> PHYSICS (Total: 800 journals)
    - ELECTRICITY AND MAGNETISM (9 journals)
    - MECHANICS (21 journals)
    - NUCLEAR PHYSICS (51 journals)
    - OPTICS (86 journals)
    - PHYSICS (576 journals)
    - SOUND (25 journals)
    - THERMODYNAMICS (32 journals)

PHYSICS (576 journals)                  1 2 3 | Last

Showing 1 - 200 of 741 Journals sorted alphabetically
Acta Acustica united with Acustica     Full-text available via subscription   (Followers: 7)
Acta Mechanica     Hybrid Journal   (Followers: 20)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
Advanced Composite Materials     Hybrid Journal   (Followers: 66)
Advanced Functional Materials     Hybrid Journal   (Followers: 50)
Advanced Materials     Hybrid Journal   (Followers: 258)
Advanced Science Focus     Free   (Followers: 3)
Advanced Structural and Chemical Imaging     Open Access   (Followers: 2)
Advanced Studies in Theoretical Physics     Open Access  
Advances in Condensed Matter Physics     Open Access   (Followers: 8)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 3)
Advances in Geophysics     Full-text available via subscription   (Followers: 6)
Advances in High Energy Physics     Open Access   (Followers: 19)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 20)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 29)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances In Physics     Hybrid Journal   (Followers: 19)
Advances in Physics : X     Open Access  
Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Remote Sensing     Open Access   (Followers: 37)
AIP Advances     Open Access   (Followers: 8)
AIP Conference Proceedings     Full-text available via subscription   (Followers: 3)
American Journal of Condensed Matter Physics     Open Access   (Followers: 4)
American Journal of Signal Processing     Open Access   (Followers: 11)
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 3)
Annalen der Physik     Hybrid Journal   (Followers: 5)
Annales Geophysicae (ANGEO)     Open Access   (Followers: 15)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3)
Annales UMCS, Physica     Open Access  
Annals of Nuclear Medicine     Hybrid Journal   (Followers: 5)
Annals of Physics     Hybrid Journal   (Followers: 4)
Annals of West University of Timisoara - Physics     Open Access   (Followers: 1)
Annual Reports on NMR Spectroscopy     Full-text available via subscription   (Followers: 4)
Annual Review of Analytical Chemistry     Full-text available via subscription   (Followers: 11)
Annual Review of Condensed Matter Physics     Full-text available via subscription  
Annual Review of Materials Research     Full-text available via subscription   (Followers: 5)
APL Materials     Open Access   (Followers: 12)
Applied Composite Materials     Hybrid Journal   (Followers: 48)
Applied Physics A     Hybrid Journal   (Followers: 7)
Applied Physics Frontier     Open Access   (Followers: 1)
Applied Physics Letters     Hybrid Journal   (Followers: 32)
Applied Physics Research     Open Access   (Followers: 3)
Applied Physics Reviews     Hybrid Journal   (Followers: 8)
Applied Radiation and Isotopes     Hybrid Journal   (Followers: 7)
Applied Spectroscopy     Full-text available via subscription   (Followers: 23)
Applied Spectroscopy Reviews     Hybrid Journal   (Followers: 5)
Archive for Rational Mechanics and Analysis     Hybrid Journal  
Asia Pacific Physics Newsletter     Hybrid Journal  
ASTRA Proceedings     Open Access   (Followers: 1)
Astronomy & Geophysics     Hybrid Journal   (Followers: 47)
Astronomy and Astrophysics Review     Hybrid Journal   (Followers: 21)
Astrophysical Journal Supplement Series     Full-text available via subscription   (Followers: 8)
Atoms     Open Access   (Followers: 1)
Attention, Perception & Psychophysics     Full-text available via subscription   (Followers: 10)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Axioms     Open Access  
Bangladesh Journal of Medical Physics     Open Access  
Bauphysik     Hybrid Journal   (Followers: 2)
Berkala Fisika Indonesia     Open Access  
Biomaterials     Hybrid Journal   (Followers: 44)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 32)
Biophysical Reviews     Hybrid Journal   (Followers: 1)
Biophysical Reviews and Letters     Hybrid Journal   (Followers: 3)
BMC Biophysics     Open Access   (Followers: 5)
Boson Journal of Modern Physics     Open Access   (Followers: 11)
Brazilian Journal of Physics     Hybrid Journal  
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Bulletin of Materials Science     Open Access   (Followers: 43)
Bulletin of the Atomic Scientists     Hybrid Journal   (Followers: 3)
Bulletin of the Lebedev Physics Institute     Hybrid Journal   (Followers: 1)
Bulletin of the Russian Academy of Sciences: Physics     Hybrid Journal   (Followers: 1)
Caderno Brasileiro de Ensino de Física     Open Access  
Canadian Journal of Physics     Hybrid Journal   (Followers: 13)
Case Studies in Nondestructive Testing and Evaluation     Open Access   (Followers: 11)
Cells     Open Access   (Followers: 2)
CERN courier. International journal of high energy physics     Free   (Followers: 7)
Chemical Physics of Solid Surfaces     Full-text available via subscription  
Chinese Journal of Astronomy and Astrophysics     Full-text available via subscription   (Followers: 13)
Chinese Journal of Chemical Physics     Hybrid Journal   (Followers: 1)
Chinese Journal of Physics     Hybrid Journal  
Chinese Physics B     Full-text available via subscription  
Chinese Physics C     Full-text available via subscription  
Chinese Physics Letters     Full-text available via subscription  
Cogent Physics     Open Access   (Followers: 1)
Cohesion and Structure     Full-text available via subscription   (Followers: 2)
Colloid Journal     Hybrid Journal   (Followers: 2)
Communications in Mathematical Physics     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Communications in Theoretical Physics     Full-text available via subscription   (Followers: 3)
Complex Analysis and its Synergies     Open Access   (Followers: 2)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 183)
Composites Part B : Engineering     Hybrid Journal   (Followers: 285)
Computational Astrophysics and Cosmology     Open Access   (Followers: 1)
Computational Condensed Matter     Open Access  
Computational Materials Science     Hybrid Journal   (Followers: 21)
Computational Mathematics and Mathematical Physics     Hybrid Journal   (Followers: 3)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Physics Communications     Hybrid Journal   (Followers: 6)
Contemporary Concepts of Condensed Matter Science     Full-text available via subscription  
Contemporary Physics     Hybrid Journal   (Followers: 26)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 7)
Contributions to Plasma Physics     Hybrid Journal   (Followers: 3)
COSPAR Colloquia Series     Full-text available via subscription   (Followers: 7)
Cryogenics     Hybrid Journal   (Followers: 51)
Current Applied Physics     Full-text available via subscription   (Followers: 4)
Current Science     Open Access   (Followers: 60)
Diagnostic and Interventional Imaging     Full-text available via subscription  
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Doklady Physics     Hybrid Journal   (Followers: 1)
Dynamical Properties of Solids     Full-text available via subscription  
ECS Journal of Solid State Science and Technology     Hybrid Journal   (Followers: 6)
Egyptian Journal of Remote Sensing and Space Science     Open Access   (Followers: 19)
EJNMMI Physics     Open Access  
Electrospinning     Open Access  
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 41)
Energy Procedia     Open Access   (Followers: 2)
Engineering Failure Analysis     Hybrid Journal   (Followers: 69)
Engineering Fracture Mechanics     Hybrid Journal   (Followers: 23)
Environmental Fluid Mechanics     Hybrid Journal   (Followers: 5)
EPJ Nonlinear Biomedical Physics     Open Access  
EPJ Quantum Technology     Open Access  
EPJ Techniques and Instrumentation     Full-text available via subscription  
EPJ Web of Conferences     Open Access  
European Journal of Physics     Full-text available via subscription   (Followers: 18)
European Physical Journal - Applied Physics     Full-text available via subscription   (Followers: 17)
European Physical Journal C     Hybrid Journal   (Followers: 1)
Europhysics News     Open Access  
Experimental Mechanics     Hybrid Journal   (Followers: 22)
Experimental Methods in the Physical Sciences     Full-text available via subscription  
Experimental Techniques     Hybrid Journal   (Followers: 56)
Exploration Geophysics     Hybrid Journal   (Followers: 4)
Few-Body Systems     Hybrid Journal  
Fire and Materials     Hybrid Journal   (Followers: 5)
Flexible Services and Manufacturing Journal     Hybrid Journal   (Followers: 1)
Fluctuation and Noise Letters     Hybrid Journal   (Followers: 1)
Fluid Dynamics     Hybrid Journal   (Followers: 14)
Fortschritte der Physik/Progress of Physics     Hybrid Journal  
Frontiers in Physics     Open Access   (Followers: 6)
Frontiers of Materials Science     Hybrid Journal   (Followers: 3)
Frontiers of Physics     Hybrid Journal   (Followers: 2)
Fusion Engineering and Design     Hybrid Journal   (Followers: 10)
Geochemistry, Geophysics, Geosystems     Full-text available via subscription   (Followers: 30)
Geografiska Annaler, Series A : Physical Geography     Hybrid Journal   (Followers: 3)
Geophysical Research Letters     Full-text available via subscription   (Followers: 130)
Geoscience and Remote Sensing, IEEE Transactions on     Hybrid Journal   (Followers: 156)
Glass Physics and Chemistry     Hybrid Journal   (Followers: 4)
Global Journal of Physics     Open Access   (Followers: 2)
Granular Matter     Hybrid Journal   (Followers: 1)
Graphs and Combinatorics     Hybrid Journal   (Followers: 7)
Gravitation and Cosmology     Hybrid Journal   (Followers: 3)
Handbook of Geophysical Exploration: Seismic Exploration     Full-text available via subscription  
Handbook of Metal Physics     Full-text available via subscription  
Handbook of Surface Science     Full-text available via subscription   (Followers: 3)
Handbook of Thermal Analysis and Calorimetry     Full-text available via subscription   (Followers: 1)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 3)
Heat Transfer - Asian Research     Hybrid Journal   (Followers: 12)
High Energy Density Physics     Hybrid Journal   (Followers: 2)
High Pressure Research: An International Journal     Hybrid Journal   (Followers: 3)
IEEE Journal of Quantum Electronics     Hybrid Journal   (Followers: 21)
IEEE Signal Processing Magazine     Full-text available via subscription   (Followers: 68)
IET Optoelectronics     Hybrid Journal   (Followers: 1)
Il Colle di Galileo     Open Access  
Image Analysis & Stereology     Open Access  
Imaging Science Journal     Hybrid Journal   (Followers: 2)
Indian Journal of Biochemistry and Biophysics (IJBB)     Open Access   (Followers: 3)
Indian Journal of Physics     Hybrid Journal   (Followers: 20)
Indian Journal of Pure & Applied Physics (IJPAP)     Open Access   (Followers: 38)
Indian Journal of Radio & Space Physics (IJRSP)     Open Access   (Followers: 36)
Industrial Electronics, IEEE Transactions on     Hybrid Journal   (Followers: 41)
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Infinite Dimensional Analysis, Quantum Probability and Related Topics     Hybrid Journal  
InfraMatics     Open Access  
Infrared Physics & Technology     Hybrid Journal   (Followers: 11)
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 8)
Intermetallics     Hybrid Journal   (Followers: 23)
International Applied Mechanics     Hybrid Journal   (Followers: 3)
International Geophysics     Full-text available via subscription   (Followers: 3)
International Heat Treatment and Surface Engineering     Hybrid Journal   (Followers: 5)
International Journal for Computational Methods in Engineering Science and Mechanics     Hybrid Journal   (Followers: 11)
International Journal for Ion Mobility Spectrometry     Hybrid Journal   (Followers: 1)
International Journal for Simulation and Multidisciplinary Design Optimization     Open Access   (Followers: 4)
International Journal of Abrasive Technology     Hybrid Journal   (Followers: 2)
International Journal of Aeroacoustics     Hybrid Journal   (Followers: 34)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 4)
International Journal of Astronomy and Astrophysics     Open Access   (Followers: 23)
International Journal of Computational Materials Science and Surface Engineering     Hybrid Journal   (Followers: 6)
International Journal of Damage Mechanics     Hybrid Journal   (Followers: 5)
International Journal of Fatigue     Hybrid Journal   (Followers: 37)
International Journal of Fracture     Hybrid Journal   (Followers: 12)
International Journal of Geometric Methods in Modern Physics     Hybrid Journal   (Followers: 2)
International Journal of Heat and Fluid Flow     Hybrid Journal   (Followers: 35)
International Journal of Low Radiation     Hybrid Journal  
International Journal of Low-Carbon Technologies     Open Access   (Followers: 1)
International Journal of Mass Spectrometry     Hybrid Journal   (Followers: 17)
International Journal of Material Forming     Hybrid Journal   (Followers: 1)
International Journal of Materials and Product Technology     Hybrid Journal   (Followers: 4)
International Journal of Mechanical Sciences     Hybrid Journal   (Followers: 12)

        1 2 3 | Last

Journal Cover Advances in Condensed Matter Physics
  [SJR: 0.248]   [H-I: 10]   [8 followers]  Follow
    
  This is an Open Access Journal Open Access journal
   ISSN (Print) 1687-8108 - ISSN (Online) 1687-8124
   Published by Hindawi Homepage  [298 journals]
  • Submicrosecond Q-Switching Er-Doped All-Fiber Ring Laser Based on Black
           Phosphorus

    • Abstract: Black phosphorus (BP), a new two-dimensional (2D) material, has been deeply developed for extensive applications in electronics and optoelectronics due to its similar physical structure to graphene and thickness dependent direct band gap. Here, we demonstrated a submicrosecond passive Q-switching Er-doped fiber laser with BP as saturable absorber (SA). The BP saturable absorber was fabricated by mechanical exfoliation method. By taking full advantage of the ultrafast relaxation time of BP-SA and careful design of compact ring cavity, we obtained stable Q-switching pulses output with a shortest duration as narrow as 742 ns. With increasing the pump power, the pulse repetition rate accreted gradually almost linearly from 9.78 to 61.25 kHz, and the pulse duration declined rapidly at lower pump power regime and retained approximate stationary at higher pump power regime from 3.05 to 0.742 μs. The experimental results indicate that BP-SA can be an effective SA for nanosecond Q-switching pulse generation.
      PubDate: Wed, 04 Oct 2017 00:00:00 +000
       
  • Over 19 W Single-Mode 1545 nm Er,Yb Codoped All-Fiber Laser

    • Abstract: We report a high-power cladding-pumped Er,Yb codoped all-fiber laser with truly single transverse mode output. The fiber laser is designed to operate at 1545 nm by the use of a pair of fiber Bragg gratings (FBGs) to lock and narrow the output spectrum, which can be very useful in generating the eye-safe ~1650 nm laser emission through the Stimulated Raman Scattering (SRS) in silica fibers that is of interest in many applications. Two pieces of standard single-mode fibers are inserted into the laser cavity and output port to guarantee the truly single-mode output as well as good compatibility with other standard fiber components. We have obtained a maximum output power of 19.2 W at 1544.68 nm with a FWHM spectral width of 0.08 nm, corresponding to an average overall slope efficiency of 31.9% with respect to the launched pump power. This is, to the best of our knowledge, the highest output power reported from simple all-fiber single-mode Er,Yb codoped laser oscillator architecture.
      PubDate: Wed, 04 Oct 2017 00:00:00 +000
       
  • Self-Reconstruction Property of a Special Speckle Pattern after
           Obstructing by an Opaque Obstruction

    • Abstract: Numerical simulation of random optical field with special autocorrelation is performed. It can be seen that the speckle pattern with special autocorrelation is different from the general speckle pattern whose autocorrelation is a Gaussian function. Furthermore, we study the propagation property of the special speckle in free space after blocking by an opaque obstruction and find the self-healing effect of speckle. In particular, we investigate the influence of size and shape of obstruction and the coherence of speckle on the speckle’s reconstruction process. We find that it is affected by the size of obstruction and the coherence of the speckle but is almost not affected by the shape of obstruction. Our results can be applied to the imaging, optical communication, and so on.
      PubDate: Tue, 26 Sep 2017 07:13:46 +000
       
  • Unprecedented Integral-Free Debye Temperature Formulas: Sample
           Applications to Heat Capacities of ZnSe and ZnTe

    • Abstract: Detailed analytical and numerical analyses are performed for combinations of several complementary sets of measured heat capacities, for ZnSe and ZnTe, from the liquid-helium region up to 600 K. The isochoric (harmonic) parts of heat capacities, , are described within the frame of a properly devised four-oscillator hybrid model. Additional anharmonicity-related terms are included for comprehensive numerical fittings of the isobaric heat capacities, . The contributions of Debye and non-Debye type due to the low-energy acoustical phonon sections are represented here for the first time by unprecedented, integral-free formulas. Indications for weak electronic contributions to the cryogenic heat capacities are found for both materials. A novel analytical framework has been constructed for high-accuracy evaluations of Debye function integrals via a couple of integral-free formulas, consisting of Debye’s conventional low-temperature series expansion in combination with an unprecedented high-temperature series representation for reciprocal values of the Debye function. The zero-temperature limits of Debye temperatures have been detected from published low-temperature data sets to be significantly lower than previously estimated, namely, 270 (±3) K for ZnSe and 220 (±2) K for ZnTe. The high-temperature limits of the “true” (harmonic lattice) Debye temperatures are found to be 317 K for ZnSe and 262 K for ZnTe.
      PubDate: Mon, 18 Sep 2017 00:00:00 +000
       
  • Surface Plasmon Resonance Enhanced Spontaneous Upconversion and Stimulated
           Emissions in Glass Ceramics Containing Ba2LaF7 Nanocrystals

    • Abstract: Glass ceramics containing Yb3+, Er3+ codoped Ba2LaF7 nanocrystals were fabricated via melt quenching method and the subsequent heating treatment. The formation of Ba2LaF7 nanocrystals in the glass ceramics was confirmed by X-ray diffraction (XRD) and transmission electron microscope (TEM). The spontaneous upconversion (UC) emission and the stimulated counterpart as a random lasing action of Er3+, which were related to the characteristic transitions of Er3+ ions, were achieved in the Yb3+, Er3+-doped Ba2LaF7 nanocrystals embedded glass ceramic hybrid. Furthermore, the absorption spectra verified the surface plasmon resonance (SPR) band of Ag, which precipitated from the matrix glasses as Ag nanoparticles (NPs). By incorporating Ag NPs in the glass ceramic hybrid, spontaneous UC emission intensity of Er3+ in visible region was significantly enhanced, while the threshold of the random lasing was decreased from 480 to 350 nJ/cm2.
      PubDate: Wed, 13 Sep 2017 00:00:00 +000
       
  • Structural Characterization of Natural and Processed Zircons with X-Rays
           and Nuclear Techniques

    • Abstract: In ceramic industry, zircon sand is widely used in different applications because zirconia plays a role as common opacifying constituent. In particular, it is used as a basic component of glazes applied to ceramic tiles and sanitary ware as well as an opacifier in unglazed bulk porcelain stoneware. Natural zircon sands are the major source of zirconium minerals for industrial applications. In this paper, long, medium, and short range studies were conducted on zirconium minerals originated from Australia, South Africa, and United States of America using conventional and less conventional techniques (i.e., X-Ray Diffraction (XRD), Positron Annihilation Lifetime Spectroscopy (PALS), and Perturbed Angular Correlations (PAC)) in order to reveal the type and the extension of the regions that constitute the metamict state of zircon sands and the modifications therein produced as a consequence of the industrial milling process and the thermal treatment in the production line. Additionally, HPGe gamma-ray spectroscopy confirms the occurrence of significant levels of natural radioactivity responsible for metamictization in the investigated zircon samples. Results from XRD, PALS, and PAC analysis confirm that the metamict state of zircon is a dispersion of submicron disordered domains in a crystalline matrix of zircon.
      PubDate: Sun, 10 Sep 2017 08:06:44 +000
       
  • Dynamics of Dispersive Wave Generation in Gas-Filled Photonic Crystal
           Fiber with the Normal Dispersion

    • Abstract: The absence of Raman and unique pressure-tunable dispersion is the characteristic feature of gas-filled photonic crystal fiber (PCF), and its zero dispersion points can be extended to the near-infrared by increasing gas pressure. The generation of dispersive wave (DW) in the normal group velocity dispersion (GVD) region of PCF is investigated. It is demonstrated that considering the self-steepening (SS) and introducing the chirp of the initial input pulse are two suitable means to control the DW generation. The SS enhances the relative average intensity of blue-shift DW while weakening that of red-shift DW. The required propagation distance of DW emission is markedly varied by introducing the frequency chirp. Manipulating DW generation in gas-filled PCF by the combined effects of either SS or chirp and three-order dispersion (TOD) provides a method for a concentrated transfer of energy into the targeted wavelengths.
      PubDate: Wed, 30 Aug 2017 00:00:00 +000
       
  • Theoretical Study on Effect of Defective Connection to Reservoirs in an
           Atomic-Scale Conductor

    • Abstract: We theoretically investigate the effect of a defect at the interface between a conductor and reservoirs in an atomic-scale device. Since fabrication of atomic-scale contacts is a complex task, there could be defects at the interface between the conductor and reservoirs. Such defective contacts will make it difficult to measure currents properly. In this paper, we calculate current-voltage characteristics in two-dimensional devices with a defective connection to reservoirs by using the nonequilibrium Green’s function method. Results show that the magnitude of resistance change depends on the amplitude of quantized wave functions at the position of the defect.
      PubDate: Mon, 21 Aug 2017 08:43:14 +000
       
  • Resonance Raman Scattering in TlGaSe2 Crystals

    • Abstract: The resonance Raman scattering for geometries and at temperature 10 K and infrared reflection spectra in and polarizations at 300 K were investigated. The number of () and () symmetry vibrational modes observed experimentally and calculated theoretically agree better in this case than when TlGa2Se4 crystals belong to symmetry group. The emission of resonance Raman scattering and excitonic levels luminescence spectra overlap. The lines in resonance Raman spectra were identified as a combination of optical phonons in Brillouin zone center.
      PubDate: Sun, 20 Aug 2017 07:35:42 +000
       
  • Torsional Potential Energy Surfaces of Dinitrobenzene Isomers

    • Abstract: The torsional potential energy surfaces of 1,2-dinitrobenzene, 1,3-dinitrobenzene, and 1,4-dinitrobenzene were calculated using the B3LYP functional with 6-31G(d) basis sets. Three-dimensional energy surfaces were created, allowing each of the two C-N bonds to rotate through 64 positions. Dinitrobenzene was chosen for the study because each of the three different isomers has widely varying steric hindrances and bond hybridization, which affect the energy of each conformation of the isomers as the nitro functional groups rotate. The accuracy of the method is determined by comparison with previous theoretical and experimental results. The surfaces provide valuable insight into the mechanics of conjugated molecules. The computation of potential energy surfaces has powerful application in modeling molecular structures, making the determination of the lowest energy conformations of complex molecules far more computationally accessible.
      PubDate: Sun, 20 Aug 2017 00:00:00 +000
       
  • Absorption Spectrum and Density of States of Square, Rectangular, and
           Triangular Frenkel Exciton Systems with Gaussian Diagonal Disorder

    • Abstract: Using the coherent potential approximation, we investigate the effects of disorder on the optical absorption and the density of states of Frenkel exciton systems on square, rectangular, and triangular lattices with nearest-neighbor interactions and a Gaussian distribution of transition energies. The analysis is based on an elliptic integral approach that gives results over the entire spectrum. The results for the square lattice are in good agreement with the finite-array calculations of Schreiber and Toyozawa. Our findings suggest that the coherent potential approximation can be useful in interpreting the optical properties of two-dimensional systems with dominant nearest-neighbor interactions and Gaussian diagonal disorder provided the optically active states are Frenkel excitons.
      PubDate: Mon, 14 Aug 2017 09:45:48 +000
       
  • Dispersion of Switching Processes in Ferroelectric Ceramics

    • Abstract: The influence of the switching processes on self-heating of ferroelectric PZT ceramics samples was studied in high-amplitude sine and meander electric fields in a wide frequency range of 50 to 1500 Hz. It is shown that the linear dependence of the self-heating temperature on the electric field frequency is observed only in low-frequency region. It was found that there exists a maximum on the frequency dependence of the self-heating temperature. The critical frequency corresponding to this maximum depends on both the properties of the material and geometry of the sample.
      PubDate: Mon, 03 Jul 2017 08:25:44 +000
       
  • Surfactant Assisted Stabilization of Carbon Nanotubes Synthesized by a
           Spray Pyrolysis Method

    • Abstract: Surface modification of carbon nanotubes has been an interesting issue from a composites materials point of view. A nanotubes agglomeration has to be avoided to achieve a homogeneous dispersion in a composite matrix. In this research, we report on the synthesis of carbon nanotubes using a variant of the chemical vapor deposition technique known as spray pyrolysis method. X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) studies showed that the synthesized products had an aligned structure with low purity degree, high content of catalyst particles, and a smaller amount of amorphous carbon. A secondary method was applied, which involves an acidic treatment that dissolves contaminant particles to enhance the purity of the nanotubes. Microstructural analysis, which includes XRD and SEM, indicates an effective reduction of impurities. Dispersion of the nanotubes was assessed using different surfactants, such as sodium dodecyl-sulfate (SDS) and ethylenediaminetetraacetic acid (EDTA). Finally, Raman spectroscopy, UV-Vis, and SEM techniques confirm that better results were obtained with EDTA. For EDTA and SDS surfactants, low concentrations of 0.3 mg/mL and 0.2 mg/mL were most efficient, respectively.
      PubDate: Sun, 02 Jul 2017 08:32:15 +000
       
  • Optical Orbital Angular Momentum Demultiplexing and Channel Equalization
           by Using Equalizing Dammann Vortex Grating

    • Abstract: A novel equalizing Dammann vortex grating (EDVG) is proposed as orbital angular momentum (OAM) multiplexer to realize OAM signal demultiplexing and channel equalization. The EDVG is designed by suppressing odd diffraction orders and adjusting the grating structure. The light intensity of diffraction is subsequently distributed evenly in the diffraction orders, and the total diffraction efficiency can be improved from 53.22% to 82%. By using the EDVG, OAM demultiplexing and channel equalization can be realized. Numerical simulation shows that the bit error rate (BER) of each OAM channel can decrease to when the bit SNR is 22 dB, and the intensity is distributed over the necessary order of diffraction evenly.
      PubDate: Wed, 21 Jun 2017 00:00:00 +000
       
  • Phase Transitions and Magnetocaloric Properties in MnCo1−xZrxGe
           Compounds

    • Abstract: The structural, magnetic, and magnetocaloric properties of () have been studied through X-ray diffraction, differential scanning calorimetry, and magnetization measurements. Results indicate that the partial substitution of Zr for Co in decreases the martensitic transition temperature (). For = 0.02, was found to coincide with the ferromagnetic transition temperature () resulting in a first-order magnetostructural transition (MST). A further increase in zirconium concentration ( = 0.04) showed a single transition at . The MST from the paramagnetic to ferromagnetic state results in magnetic entropy changes () of 7.2 J/kgK for = 5 T at 274 K for = 0.02. The corresponding value of the relative cooling power (RCP) was found to be 266 J/kg for = 5 T. The observed large value of MCE and RCP makes this system a promising material for magnetic cooling applications.
      PubDate: Tue, 13 Jun 2017 07:38:54 +000
       
  • Synthesis of a Novel Ce-bpdc for the Effective Removal of Fluoride from
           Aqueous Solution

    • Abstract: Ce-1,1′-biphenyl-4,4′-dicarboxylic acid (Ce-bpdc), a novel type of metal organic framework, was synthesized and applied to remove excessive fluoride from water. The structure and morphology of Ce-bpdc were measured by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The effects, such as saturated adsorption capacity, , and pH, were investigated. The optimal pH value for fluoride adsorption was the range from 5 to 6. The coexisting bicarbonate anions have a little influence on fluoride removal. The fluoride adsorption over the Ce-bpdc adsorbent could reach its equilibrium in about 20 min. The Ce-bpdc coordination complex exhibited high binding capacity for fluoride ions. The maximum adsorption capacity calculated from Langmuir model was high up to 45.5 mg/g at 298 K (pH = 7.0) and the removal efficiency was greater than 80%. In order to investigate the mechanism of fluoride removal, various adsorption isotherms such as Langmuir and Freundlich were fitted. The experimental data revealed that the Langmuir isotherm gave a more satisfactory fit for fluoride removal. Finally, the tested results of ground water samples from three places, Yuefang, Jiangji, and Sanyi which exhibited high removal efficiency, also demonstrate the potential utility of the Ce-bpdc as an effective adsorbent.
      PubDate: Mon, 12 Jun 2017 00:00:00 +000
       
  • Excitation Spectrum of the Néel Ensemble of Antiferromagnetic
           Nanoparticles as Revealed in Mössbauer Spectroscopy

    • Abstract: The excitation spectrum of the Néel ensemble of antiferromagnetic nanoparticles with uncompensated magnetic moment is deduced in the two-sublattice approximation following the exact solution of equations of motion for magnetizations of sublattices. This excitation spectrum represents four excitation branches corresponding to the normal modes of self-consistent regular precession of magnetizations of sublattices and the continuous spectrum of nutations of magnetizations accompanying these normal modes. Nontrivial shape of the excitation spectrum as a function of the value of uncompensated magnetic moment corresponds completely to the quantum-mechanical calculations earlier performed. This approach allows one to describe also Mössbauer absorption spectra of slowly relaxing antiferromagnetic and ferrimagnetic nanoparticles and, in particular, to give a phenomenological interpretation of macroscopic quantum effects observed earlier in experimental absorption spectra and described within the quantum-mechanical representation.
      PubDate: Sun, 11 Jun 2017 06:41:05 +000
       
  • Fast Switching 4H-SiC P-i-n Structures Fabricated by Low Temperature
           Diffusion of Al

    • Abstract: P-i-n 4H-SiC diode structures are fabricated by a new approach which is low temperature diffusion of aluminium (Al) in SiC using flow of vacancy defects from surface into volume of crystal. In conventional diffusion in SiC, the operating temperature is usually >2050°C while, in this approach, the diffusion temperature is between 1150 and 1300°C. As the conditions of formation of junction in this method essentially differ from conventional diffusion (low temperature and process of diffusion are accompanied by forming structure defects), it is interesting to identify the advantages and disadvantages of a new method of diffusion. Fabricated p-i-n structures have low breakdown voltage between 80 and 140 V (due to the influence of dislocations and micropipes) and are capable of operating at temperatures up to 300°C. Structure has fast switching time and duration of the reverse recovery current less than 10 ns. We believe that because of low diffusion temperature, the concentration of nitrogen related trapping levels is relatively low and as a result the fast switching time is observed in our samples. It has been shown that this low temperature diffusion technology can be used to fabricate -region and high resistive -region of SiC diode in single-step process.
      PubDate: Tue, 30 May 2017 00:00:00 +000
       
  • Amorphization Effect for Kondo Semiconductor CeRu2Al10

    • Abstract: We measured the magnetic susceptibility , electrical resistivity , and specific heat of a sputtered amorphous (a-)CeRu2Al10 alloy. value for a-CeRu2Al10 alloy follows a Curie-Weiss paramagnetic behavior in the high-temperature region, and magnetic transition was not observed down to 2 K. The effective paramagnetic moment is 1.19 /Ce-atom. The resistivity shows a typical disordered alloy behavior, that is, small temperature dependence for the whole temperature range. We observed an enhancement of and in the low-temperature region of  K. The enhancement in is suppressed by applying a magnetic field. It is suggested that this behavior is caused by the Kondo effect.
      PubDate: Wed, 24 May 2017 07:57:39 +000
       
  • Resonant Scattering and Energy Relaxation in Quantum Dot Systems

    • Abstract: We propose a new Auger-like mechanism for energy relaxation in quantum dots (QD) driven by resonant scattering of delocalized wetting layer (WL) carriers. It is demonstrated that resonant scattering leads to a considerable increase in the relaxation rate that can explain experimentally obtained relaxation rates. Analytical results for the relaxation rate are obtained for rectangular dots revealing a weak logarithmic dependence on the dot depth and level density. Comparing results for a rectangular and a parabolic QD model we conclude that the relaxation rate is not very sensitive to a chosen model.
      PubDate: Thu, 11 May 2017 07:34:11 +000
       
  • Characteristic Evaluation of Organic Light-Emitting Diodes Prepared with
           Stamp Printing Technique

    • Abstract: We have reported on a stamp printing technique that uses PET release film as a printing stamp to deposit TPBi thin film served as the electron transport layer of the organic light-emitting diodes. TPBi thin film was printed with a good uniformity and resolution. Effect of deposition conditions on optical and electrical properties and surface roughness of TPBi thin film have been studied under spectroscopy and atomic force microscopy, respectively. It is found that characteristic of TPBi thin film is improved via controlled stamp temperature and time. Since TPBi thin film exhibits the surface morphology comparable to that of conventional spin-coating thin film, our findings suggest that PET release film-based stamp printing approach is possible to use as an alternative deposition of the organic thin film as compared with a traditional one.
      PubDate: Wed, 10 May 2017 08:16:59 +000
       
  • Light Polarization Using Ferrofluids and Magnetic Fields

    • Abstract: We are presenting an experimental setup based on polarized light, enabling the visualization of the magnetic field of magnetic assemblies using a Hele-Shaw cell filled with ferrofluids. We have simulated the observed patterns with hypergeometric polynomials.
      PubDate: Tue, 09 May 2017 00:00:00 +000
       
  • Stability and Dissipation of Many Components’ Systems and
           Application to Metamaterials

    • Abstract: Dykhne’s method, based on rotational symmetry of two-dimensional equations of constant direct current, was applied to study the properties of the medium, consisting of reactances—of inductors and capacitors (nondissipative elements). The exact solution for the 4-component system consisting of the two different types of 2 inductors and 2 capacitors, randomly placed and connected, was obtained. The obtained solution for investigated system has the two features: (1) the finite dissipation in the nondissipative system of inductors and capacitors; (2) appearance of plateau—the constant value of effective conductivity in a wide range of concentrations of components. The obtained results were useful for description of composite metamaterials.
      PubDate: Sun, 30 Apr 2017 13:09:46 +000
       
  • Magnetic Properties of Sm-Fe-N/Co-B Composite Magnets Prepared by Chemical
           Reduction

    • Abstract: An attempt was made to produce Sm-Fe-N/Co-B composite magnets by chemical reduction. It was found that a composite powder consisting of Sm-Fe-N particles coated with fine Co-B particles could be obtained by chemical reduction. The Sm-Fe-N/Co-B composite powder acted as a single hard magnetic phase and showed a smooth hysteresis loop. The composite powder exhibited a higher remanence of 93.1 Am2/kg and a higher coercivity of 0.45 MA/m than a mixture of the Sm-Fe-N powder and Co-B powder prepared by a similar procedure but using a higher concentration of aqueous solution for the chemical reduction.
      PubDate: Mon, 24 Apr 2017 00:00:00 +000
       
  • Stability of Bar Code Information Stored in Magnetic Nanowire Arrays

    • Abstract: Firmware applications such as security codes, magnetic keys, and similar products can be stored in magnetic bar codes similar to optical bar codes. This can be achieved on the triangular lattice present in porous alumina, whose pori can be filled by magnetic material, over which magnetic bar codes can be inscribed. We study the conditions to improve the durability of the stored information by minimizing the repulsive energy among wires with parallel magnetization within the same bar but interacting with attractive energy with wires in the neighboring bar. The following parameters are varied to minimize the energy of the system: relative amount of magnetization orientation within the bar code area in any orientation, width of the bars, and distribution of wider bars to the outside or to the inside of the code. It is found that durability of the code is favored for equal amount of magnetization in each direction, abundance of narrow bars trying to locate a few wider ones towards the center. Three real commercial optical bar codes taken at random were mapped into magnetic bar codes; it is found that the corresponding magnetic energies are similar to those analyzed here which provides a realistic test for this approach.
      PubDate: Wed, 19 Apr 2017 09:24:12 +000
       
  • Intrinsic and Extrinsic Ferromagnetism in Co-Doped Indium Tin Oxide
           Revealed Using X-Ray Magnetic Circular Dichroism

    • Abstract: The effects of high-temperature annealing on ferromagnetic Co-doped Indium Tin Oxide (ITO) thin films have been investigated using X-ray diffraction (XRD), magnetometry, and X-Ray Magnetic Circular Dichroism (XMCD). Following annealing, the magnetometry results indicate the formation of Co clusters with a significant increase in the saturation magnetization of the thin films arising from defects introduced during cluster formation. However, sum rule analysis of the element-specific XMCD results shows that the magnetic moment at the Co sites is reduced after annealing. The effects of annealing demonstrate that the ferromagnetism observed in the as-deposited Co-doped ITO films arises from intrinsic defects and cannot be related to the segregation of metallic Co clusters.
      PubDate: Thu, 13 Apr 2017 06:44:35 +000
       
  • The Tunnelling Current through Oscillating Resonance and the Sisyphus
           Effect

    • Abstract: The tunnelling current through an oscillating resonance level is thoroughly investigated exactly numerically and with several approximations—analytically. It is shown that while the oscillations can increase the tunnelling current (and in several cases the increase is exponentially large), their main effect is to reduce it dramatically at certain energies. In fact, the current in the presence of the oscillations cannot increase the maximum current of the adiabatic solution. That is why, while the elevator effect does occur in this system, the Sisyphus effect is the more dominant and prominent one.
      PubDate: Tue, 11 Apr 2017 00:00:00 +000
       
  • Study of Low Voltage Prebreakdown Sites in Multicrystalline Si Based Cells
           by the LBIC, EL, and EDS Methods

    • Abstract: Breakdown sites in multicrystalline Si solar cells have been studied by reverse-bias electroluminescence, electron beam induced current (EBIC) and laser beam induced current (LBIC), and Energy Dispersive X-Ray Spectroscopy methods. In the breakdown sites revealed by EL at small reverse bias (~5 V), the enhanced aluminum and oxygen concentration is revealed. Such breakdowns can be located inside the depletion region because they are not revealed by the EBIC or LBIC methods. Breakdowns revealed by EL at larger bias correlate well with extended defects in the EBIC and LBIC images.
      PubDate: Mon, 10 Apr 2017 00:00:00 +000
       
  • Design and Fabrication of a Novel Wideband DNG Metamaterial with the
           Absorber Application in Microwave X-Band

    • Abstract: A novel metamaterial, which exhibits a wideband double negative behavior in X-band, is proposed, designed, and investigated in this paper. The metamaterial is composed of modified S-shaped split-ring resonators (S-SRR). The periodic structure is designed and simulated using CST MWs. Next, the experiments are carried out, and it is shown that the simulation and the experimental results agree well and the designed structure has a wide bandwidth in X-band. An absorber application of this metamaterial is also provided, and the structure can be used as an absorber with absorption rate of over 80% for the polarization angles between 0° and 40°.
      PubDate: Sun, 26 Mar 2017 00:00:00 +000
       
  • Influence of Pressure on the Temperature Dependence of Quantum Oscillation
           Phenomena in Semiconductors

    • Abstract: The influence of pressure on the oscillations of Shubnikov-de Haas (ShdH) and de Haas-van Alphen (dHvA) in semiconductors is studied. Working formula for the calculation of the influence of hydrostatic pressure on the Landau levels of electrons is obtained. The temperature dependence of quantum oscillations for different pressures is determined. The calculation results are compared with experimental data. It is shown that the effect of pressure on the band gap is manifested to oscillations and ShdH and dHvA effects in semiconductors.
      PubDate: Mon, 20 Mar 2017 00:00:00 +000
       
 
 
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