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  Subjects -> PHYSICS (Total: 736 journals)
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PHYSICS (537 journals)                  1 2 3 4 5 6 | Last

Acta Acustica united with Acustica     Full-text available via subscription   (Followers: 7)
Acta Mechanica     Hybrid Journal   (Followers: 15)
Acta Physica Slovaca     Open Access   (Followers: 3)
Advanced Composite Materials     Hybrid Journal   (Followers: 10)
Advanced Functional Materials     Hybrid Journal   (Followers: 31)
Advanced Materials     Hybrid Journal   (Followers: 283)
Advances in Condensed Matter Physics     Open Access   (Followers: 6)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 3)
Advances in Geophysics     Full-text available via subscription   (Followers: 4)
Advances in High Energy Physics     Open Access   (Followers: 12)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 1)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 11)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 13)
Advances in OptoElectronics     Open Access   (Followers: 3)
Advances In Physics     Hybrid Journal   (Followers: 6)
Advances in Physics Theories and Applications     Open Access   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 7)
Advances in Synchrotron Radiation     Hybrid Journal   (Followers: 1)
AIP Advances     Open Access   (Followers: 4)
AIP Conference Proceedings     Full-text available via subscription  
American Journal of Applied Sciences     Open Access   (Followers: 27)
American Journal of Condensed Matter Physics     Open Access   (Followers: 2)
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 1)
Annalen der Physik     Hybrid Journal   (Followers: 2)
Annales Geophysicae (ANGEO)     Open Access   (Followers: 3)
Annales Henri PoincarĂ©     Hybrid Journal   (Followers: 2)
Annales UMCS, Physica     Open Access  
Annals of Nuclear Medicine     Hybrid Journal   (Followers: 3)
Annals of Physics     Hybrid Journal   (Followers: 2)
Annual Reports on NMR Spectroscopy     Full-text available via subscription   (Followers: 1)
Annual Review of Analytical Chemistry     Full-text available via subscription   (Followers: 9)
Annual Review of Condensed Matter Physics     Full-text available via subscription   (Followers: 1)
Annual Review of Materials Research     Full-text available via subscription   (Followers: 4)
APL Materials     Open Access   (Followers: 2)
Applied Composite Materials     Hybrid Journal   (Followers: 8)
Applied Physics A     Hybrid Journal   (Followers: 9)
Applied Physics Frontier     Open Access   (Followers: 1)
Applied Physics Letters     Hybrid Journal   (Followers: 23)
Applied Physics Research     Open Access   (Followers: 6)
Applied Physics Reviews     Hybrid Journal   (Followers: 7)
Applied Radiation and Isotopes     Hybrid Journal   (Followers: 5)
Applied Remote Sensing Journal     Open Access   (Followers: 8)
Applied Spectroscopy     Full-text available via subscription   (Followers: 12)
Applied Spectroscopy Reviews     Hybrid Journal   (Followers: 2)
Archive for Rational Mechanics and Analysis     Hybrid Journal   (Followers: 3)
Astronomy & Geophysics     Hybrid Journal   (Followers: 1)
Astrophysical Journal Letters     Full-text available via subscription   (Followers: 2)
Astrophysical Journal Supplement Series     Full-text available via subscription   (Followers: 2)
Atoms     Open Access  
Attention, Perception & Psychophysics     Full-text available via subscription   (Followers: 4)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 5)
Axioms     Open Access  
Bangladesh Journal of Medical Physics     Open Access  
Bauphysik     Hybrid Journal   (Followers: 1)
Biomaterials     Hybrid Journal   (Followers: 25)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 14)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 11)
Biomedical Imaging and Intervention Journal     Open Access   (Followers: 5)
Biophysical Reviews     Hybrid Journal  
Biophysical Reviews and Letters     Hybrid Journal   (Followers: 3)
BMC Biophysics     Open Access   (Followers: 7)
BMC Nuclear Medicine     Open Access   (Followers: 5)
Brazilian Journal of Physics     Hybrid Journal  
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 5)
Bulletin of Materials Science     Open Access   (Followers: 35)
Bulletin of the Atomic Scientists     Full-text available via subscription   (Followers: 4)
Bulletin of the Lebedev Physics Institute     Hybrid Journal   (Followers: 1)
Bulletin of the Russian Academy of Sciences: Physics     Hybrid Journal  
Caderno Brasileiro de Ensino de FĂ­sica     Open Access  
Canadian Journal of Physics     Full-text available via subscription   (Followers: 1)
Cells     Open Access  
Central European Journal of Physics     Hybrid Journal   (Followers: 1)
Chinese Journal of Astronomy and Astrophysics     Full-text available via subscription  
Chinese Journal of Chemical Physics     Hybrid Journal   (Followers: 1)
Chinese Physics B     Full-text available via subscription  
Chinese Physics C     Full-text available via subscription  
Chinese Physics Letters     Full-text available via subscription  
Cohesion and Structure     Full-text available via subscription   (Followers: 1)
Colloid Journal     Hybrid Journal   (Followers: 2)
Communications in Mathematical Physics     Hybrid Journal   (Followers: 2)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 3)
Communications in Theoretical Physics     Full-text available via subscription   (Followers: 1)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 26)
Composites Part B : Engineering     Hybrid Journal   (Followers: 24)
Computational Materials Science     Hybrid Journal   (Followers: 15)
Computational Mathematics and Mathematical Physics     Hybrid Journal   (Followers: 1)
Computational Particle Mechanics     Hybrid Journal  
Computational Science and Discovery     Full-text available via subscription  
Computer Physics Communications     Hybrid Journal  
Contemporary Concepts of Condensed Matter Science     Full-text available via subscription  
Contemporary Physics     Hybrid Journal   (Followers: 9)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 3)
Contributions to Plasma Physics     Hybrid Journal   (Followers: 2)
COSPAR Colloquia Series     Full-text available via subscription  
Cryogenics     Hybrid Journal   (Followers: 11)
Current Applied Physics     Full-text available via subscription   (Followers: 4)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Differential Equations and Nonlinear Mechanics     Open Access   (Followers: 4)
Doklady Physics     Hybrid Journal   (Followers: 1)
Dynamical Properties of Solids     Full-text available via subscription  

        1 2 3 4 5 6 | Last

Journal Cover Advances in Condensed Matter Physics
   [8 followers]  Follow    
  This is an Open Access Journal Open Access journal
     ISSN (Print) 1687-8108 - ISSN (Online) 1687-8124
     Published by Hindawi Publishing Corporation Homepage  [344 journals]   [SJR: 0.6]   [H-I: 7]
  • Effect of UV Laser Conditioning on the Structure of KDP Crystal

    • Abstract: Multiparametric raster scanning experiments for KDP crystals are carried out to study the laser conditioning efficiency as a function of laser fluence, fluence step, and pulse sequence by using ultraviolet (UV) laser irradiation with pulse duration of approximately 7 ns. It indicates that damage resistance of KDP can be enhanced after conditioning process. And laser conditioning efficiency depends on the maximal fluence which is below the damage threshold. Raman spectra and photothermal absorption have also been studied on KDP crystals before and after multiparametric laser conditioning. Photothermal absorption data reveal that absorbance of conditioned KDP crystal decreases with the increase of laser fluence and the damage threshold of low absorption area is higher. Raman analysis reveals that the effectiveness of laser conditioning relies mainly on the individual mode of PO4 molecule.
      PubDate: Wed, 18 Jun 2014 07:15:47 +000
       
  • Effect of Heating Method on Hydrogen Production by Biomass Gasification in
           Supercritical Water

    • Abstract: The glucose as a test sample of biomass is gasified in supercritical water with different heating methods driven by renewable solar energy. The performance comparisons of hydrogen production of glucose gasification are investigated. The relations between temperature raising speed of reactant fluid, variation of volume fraction, combustion enthalpy, and chemical exergy of H2 of the product gases with reactant solution concentration are presented, respectively. The results show that the energy quality of product gases with preheating process is higher than that with no preheating unit for hydrogen production. Hydrogen production quantity and gasification rate of glucose decrease obviously with the increase of concentration of material in no preheating system.
      PubDate: Tue, 17 Jun 2014 09:09:43 +000
       
  • A Model to Describe the Magnetomechanical Behavior of Martensite in
           Magnetic Shape Memory Alloy

    • Abstract: A model to describe the constitutive behavior of magnetic shape memory alloy composed with pure martensite is proposed based on the analysis of variants reorientation. A hyperbolic tangent expression is given to describe the variants transition during magnetic and mechanical loading process. The main features of magnetic shape memory alloy, such as pseudoelastic and partially pseudoelastic behavior as well as minor hysteretic loops, can be successfully replicated with the proposed model. A good agreement is achieved between calculated results and experimental data for NiMnGa single crystal.
      PubDate: Tue, 17 Jun 2014 06:21:56 +000
       
  • Defects-Induced Hot Spots in TATB

    • Abstract: We investigate the interaction between the laser and energetic materials with different defects. The three-dimensional models of triaminotrinitrobenzene (TATB) explosives containing spherical pores, craters, and cracks are established, respectively. The laser ignition process of TATB is simulated with three-dimensional finite difference time domain (3D-FDTD) method to study the electromagnetic field distribution surrounding these defects with 355 nm laser incidence. It indicates that the larger defects in the TATB energetic materials have the stronger electric field modulations to initial incident laser for all the three defects, which is easier to lead to the generation of hot spots. Furthermore, TATB materials with spherical pore defects and crater defects are easier to form hot spots than those with narrow crack defects.
      PubDate: Tue, 17 Jun 2014 05:50:00 +000
       
  • Dielectric Studies on Fe3O4 Nanodoped --Alkyloxybenzoic Acids

    • Abstract: The stability of phase transition temperatures and textural changes for thermotropic pure and nanodoped --alkyloxybenzoic acid mesogens were aimed to study at considerable time periods. Frequency and temperature dependent dielectric constant and dielectric loss for the pure and nanodoped liquid crystals were carried out. Significant anomalies in dielectric studies were observed near phase transitions when dielectric constant and dielectric loss had been measured as a function of temperature and frequency. Changes in dielectric constant and loss were observed and there were no apparent changes at high frequencies instead maintaining constant values. The variations in conductivity, activation energy, and relaxation times had also been studied in the nematic and smectic phases. The temperature dependent dielectric constant stability (temperature coefficient of dielectric constant ) had shown shift in the observed frequency range of thermotropic liquid crystals corresponding to the change in the dielectric constant values.
      PubDate: Mon, 16 Jun 2014 12:03:08 +000
       
  • Hydrogen Production by Supercritical Water Gasification of Biomass with
           Homogeneous and Heterogeneous Catalyst

    • Abstract: Biomass gasification in supercritical water is a clean and efficient way to convert biomass to hydrogen-rich gaseous products. Appropriate catalyst can lower the reaction temperature to guarantee the technological and economic feasibility. This paper selects Ca(OH)2, Na2CO3, K2CO3, NaOH, KOH, LiOH, and ZnCl2 as typical homogeneous catalysts and three kinds of Raney-Ni, dolomite, and olivine as typical heterogeneous catalysts. The catalyst effects are investigated in the process of biomass gasification in supercritical water with the temperature of 400°C, pressure of  MPa, and residence time of 20 min. The experimental results show that Raney-Ni has the best hydrogen selectivity and hydrogen yield. The mixture of NaOH with Raney-Ni was investigated in order to research the synergistic effect of different catalysts. The experimental results show that Raney-Ni and NaOH have a synergistic effect in the biomass gasification in supercritical water.
      PubDate: Mon, 16 Jun 2014 06:15:08 +000
       
  • The Electric Field Modulation by Hemisphere Damage Sites in Fused Silica
           Subsurface

    • Abstract: The effect of defect density on the electric field modulation to incident laser is investigated in this work. Based on the actual defect distribution in fused silica subsurface, the three-dimension grid model of defect sites is constructed firstly. Then, the three-dimension finite-difference time-domain method is developed to solve the Maxwell equations. The electric field intensity in the vicinity of the defect sites located in front subsurface of fused silica is numerically calculated. The relationships between the maximal electric field intensity in fused silica and the geometry of the defect sites are given. The simulated results reveal that the modulation becomes more remarkable with the increase of defects density firstly and then decrease. Besides, the effect of the distribution mode of defects on modulation is discussed. Meanwhile, the possible physical mechanism is analyzed in detail.
      PubDate: Wed, 11 Jun 2014 09:33:49 +000
       
  • Revisiting the Zinc-Blende/Wurtzite Heterocrystalline Structure in CdS

    • Abstract: The band offset at CdS zinc-blende (ZB)/wurtzite (WZ) heterocrystalline interface was revisited using the first principles calculations with the local density approximation (LDA), generalized gradient approximation (GGA), and Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional. It was revealed that, unlike most IV, III-V, and II-VI semiconductors, the band alignment at CdS ZB/WZ heterocrystalline interface was of type-I with straddling lineup of band edges, which was irrespective of the exchange-correlation energy functional, the thickness of ZB and WZ segments, and the ZB/WZ interface location. The partial charge densities of VBM and CBM states were separated around two adjacent interfaces in one unit cell of heterocrystalline superlattice. This type of carrier localization was mainly attributed to the spontaneous polarization occurring in the WZ segment rather than the band offset at the interface.
      PubDate: Tue, 10 Jun 2014 00:00:00 +000
       
  • Preparation and Characterization of Novel Fe2O3-Flaky Coated Carbon Fiber
           by Electrospinning and Hydrothermal Methods

    • Abstract: A novel hierarchical nanostructure of -flaky coated carbon fibers was produced by the electrospinning process followed by a hydrothermal technique. First, electrospinning of a colloidal solution that consisted of ferric nitrate and polyacrylonitrile (PAN) was performed to produce PAN nanofibers. Then electrospun nanofiber was stabilized and calcinated in nitrogen at 800°C for 2 h to produce carbon nanofibers (CNFs) which were exploited to produce -flaky structure using hydrothermal technique. The as-obtained products were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results revealed that flakes were successfully grown on the CNFs substrates, and the coverage of flakes could be controlled by simply adjusting the hydrothermal pH value and time. -flaky coated carbon fibers displayed high photocatalytic activity toward degradation of methyl orange (MO) under visible light irradiation.
      PubDate: Wed, 04 Jun 2014 07:25:43 +000
       
  • Investigation of Control of Residual Stress Induced by CO2 Laser-Based
           Damage Mitigation of Fused Silica Optics

    • Abstract: A CO2 laser-based annealing technique for the mitigation of damaged sites of fused silica is studied to suppress the residual stress left on the surface. The laser annealing by a linear decrease of the CO2 laser power effectively reduces the residual stress. The residual stress of mitigated sites is characterized by polarimetry, the reduction of the maximum retardance around the mitigated sites with the exposure time of laser annealing fits a stretched exponential equation, and the maximum retardance with optimal laser annealing is reduced (36 ± 3)% compared to that without laser annealing. The residual stress regions are destructively characterized by introducing damage. The critical size of damage leading to fracture propagation for the mitigated sites without laser annealing is in the range of 120~230 μm, and the corresponding critical size of damage for the mitigated sites with laser annealing is larger than 600 μm. According to the relationship between maximum damage size and critical stress, the residual stress without laser annealing is in the range of 28–39 MPa and the residual stress with laser annealing is less than 17 MPa. These results indicate that the CO2 laser-based annealing technique has a positive effect on the control of residual stress induced by CO2 laser-based damage mitigation.
      PubDate: Tue, 03 Jun 2014 07:05:45 +000
       
  • Evolution of Oxygen Deficiency Center on Fused Silica Surface Irradiated
           by Ultraviolet Laser and Posttreatment

    • Abstract: Evolution of oxygen deficiency centers (ODCs) on a fused silica surface irradiated using a 355 nm ultraviolet (UV) laser beam in both vacuum and atmospheric conditions was quantitatively studied using photoluminescence and X-ray photoelectron spectroscopy. When the fusedsilica surface was exposed to the UV laser in vacuum, the laser damage threshold was decreased whereas the concentration of the ODCs was increased. For the fuse silica operated under the high power lasers, creation of ODCs on their surface resulted from the UV laser irradiation, and this is more severe in a high vacuum. The laser fluence and/or laser intensity have significant effects on the increase of the ODCs concentration. The ODCs can be effectively repaired using postoxygen plasma treatment and UV laser irradiation in an excessive oxygen environment. Results also demonstrated that the “gain” and “loss” of oxygen at the silica surface is a reversible and dynamic process.
      PubDate: Thu, 29 May 2014 13:34:32 +000
       
  • Electronic Structure and Optical Properties of Alloy

    • Abstract: A first-principles study has been performed to investigate the structural and electronic properties of the system. The simulations are based upon the generalized gradient approximation (GGA) within the framework of density functional theory (DFT). Calculations are performed to different Bi concentrations. The lattice constant of increases with Bi concentration while the alloy remains in the zinc-blende structure. The band gap of clearly shrinks with the Bi concentration. The optical transition of Bi dopant in GaAs exhibits a red shift. Besides, other important optical constants, such as the dielectric function, reflectivity, refractive index, and loss function also change significantly.
      PubDate: Wed, 28 May 2014 07:10:46 +000
       
  • Experimental Study of Laser Cladding Methods on Water Erosion Resistance
           to Low Pressure Blades Materials of Steam Turbine

    • Abstract: An experimental apparatus was built to study the effects of liquid-solid impact on laser cladding processing specimens of 17-4PH stainless steel material in the present investigation. Then the result of specimens without laser surface process was compared. The impact effect on the specimens was observed using the three-dimensional digital microscope. The depth of laser cladding and substrate material caused by liquid droplet impact was studied in detail and measured. The accuracy and reliability of the experimental system and computing methods were also verified. The depth of the impact area of laser cladding specimens was distributed in the range of 0.5–1.5 μm while the 17-4PH group was distributed in the range of 2.5–3.5 μm. In contrast with specimens without laser surface processing, the material processed by laser cladding has significantly higher resistance to water erosion.
      PubDate: Sun, 25 May 2014 11:03:55 +000
       
  • Diffusion-Controlled Growth of Oxygen Bubble Evolved from Nanorod-Array
           TiO2 Photoelectrode

    • Abstract: Nanorod-array structure gains its popularity in photoelectrode design for water splitting. However, the structure’s effects on solid-liquid interface interaction and reaction product transportation still remain unsolved. Gas bubble generally evolved from photoelectrodes, which provides a starting point for the problem-solving. Based on this, investigations on the gas-evolving photoelectrode are carried out in this paper. By experimental studies of wettability on the photoelectrode nanorod-array surface and oxygen bubble growth from anode, we analyzed the interaction affecting the gas-solid-liquid contact behaviors and product transportation mechanism, which is controlled by diffusion due to the concentration gradient of dissolved gases in the aqueous electrolyte and the microconvection caused by the bubble interface movement. In the end, based on the bubble growth characteristics of in the experiment, a model describing the product transport mechanism was presented.
      PubDate: Sun, 25 May 2014 08:08:31 +000
       
  • Derivation of Line Shape Function in the Optical Conductivity by a New
           Diagram Method

    • Abstract: A new diagram method for the line shape function in the optical conductivity formula is introduced and the result obtained applying the method to an electron-phonon system is compared with that derived using the projection-reduction method. The result satisfies the population criterion, which states that the distribution functions for electrons and phonons should be combined in multiplicative forms and gives physical intuition to quantum dynamics of electrons in a solid. This method can be called the “KC diagram” method because it originates from the proper application of the Kang-Choi reduction identity and a state-dependent projection operator.
      PubDate: Sun, 25 May 2014 05:31:28 +000
       
  • Progress in ZnO Acceptor Doping: What Is the Best Strategy'

    • Abstract: This paper reviews the recent progress in acceptor doping of ZnO that has been achieved with a focus toward the optimum strategy. There are three main approaches for generating p-type ZnO: substitutional group IA elements on a zinc site, codoping of donors and acceptors, and substitution of group VA elements on an oxygen site. The relevant issues are whether there is sufficient incorporation of the appropriate dopant impurity species, does it reside on the appropriate lattice site, and lastly whether the acceptor ionization energy is sufficiently small to enable significant p-type conduction at room temperature. The potential of nitrogen doping and formation of the appropriate acceptor complexes is highlighted although theoretical calculations predict that nitrogen on an oxygen site is a deep acceptor. We show that an understanding of the growth and annealing steps to achieve the relevant acceptor defect complexes is crucial to meet requirements.
      PubDate: Thu, 22 May 2014 11:47:15 +000
       
  • Laser Cleaning Using Q-Switched Nd:YAG Laser of Low Carbon Steel Alloys

    • Abstract: This paper represents the efforts to achieve the laser cleaning process of low carbon steel alloys AISI1005 and AISI1012 with 0.65 mm and 1 mm thickness, respectively. The cleaning experiments were performed with a Q-switched Nd:YAG nanosecond laser at wavelengths of 1064 nm and 532 nm. The parameters that have been selected for the present work are peak power which varies as 5, 15, 30, 40, and 50 MW and pulse repetition rate which varies from 1 to 6 Hz by 1 Hz increment. Effects of these parameters on the microstructure and the mechanical properties of the two alloys have been realized. Also predicted results of analytical model regarding the depth were compared with the experimental results which show a good agreement between both.
      PubDate: Tue, 20 May 2014 00:00:00 +000
       
  • Effects of Absorber Emissivity on Thermal Performance of a Solar Cavity
           Receiver

    • Abstract: Solar cavity receiver is a key component to realize the light-heat conversion in tower-type solar power system. It usually has an aperture for concentrated sunlight coming in, and the heat loss is unavoidable because of this aperture. Generally, in order to improve the thermal efficiency, a layer of coating having high absorptivity for sunlight would be covered on the surface of the absorber tubes inside the cavity receiver. As a result, it is necessary to investigate the effects of the emissivity of absorber tubes on the thermal performance of the receiver. In the present work, the thermal performances of the receiver with different absorber emissivity were numerically simulated. The results showed that the thermal efficiency increases and the total heat loss decreases with increasing emissivity of absorber tubes. However, the thermal efficiency increases by only 1.6% when the emissivity of tubes varies from 0.2 to 0.8. Therefore, the change of absorber emissivity has slight effect on the thermal performance of the receiver. The reason for variation tendency of performance curves was also carefully analyzed. It was found that the temperature reduction of the cavity walls causes the decrease of the radiative heat loss and the convective heat loss.
      PubDate: Thu, 08 May 2014 11:31:50 +000
       
  • Micromagnetic Simulation of Domain Walls in Exchange Spring Trilayers

    • Abstract: Chiral domain wall structures in ferromagnetic exchange spring soft/hard/soft and hard/soft/hard trilayers were investigated with micromagnetic simulation, which enables us to fully characterize the nucleation and growth of buried domain walls in layered ferromagnetic thin films. Simulated results show that the trilayers are both exchange coupled and presenting chiral spin structures. Detailed features of field-dependent domain walls evolution in the spring magnets are also revealed. In process of remagnetization, the spin structure of soft/hard/soft is energetically more stable than that of hard/soft/hard.
      PubDate: Thu, 08 May 2014 00:00:00 +000
       
  • Fabrication of TiO2 Nanofilm Photoelectrodes on Ti Foil by Ti Ion
           Implantation and Subsequent Annealing

    • Abstract: The TiO2 photoelectrodes fabricated on the substrate of Ti foils by Ti ions implantation and subsequent annealing at different temperatures were applied for water splitting. The size of TiO2 nanoparticles increased with annealing temperatures, and the GIXRD patterns and Raman spectra demonstrate that the phase of TiO2 turns to rutile at high temperature. The photoelectrochemical (PEC) and X-ray photoelectron spectroscopy (XPS) spectra of the valence band demonstrate that the samples annealed at 400 and 500°C show the n-type property. The sample annealed at 600°C shows the weak p-type TiO2 property. For the sample annealed at 700°C, the negative photocurrent is main, which mainly performs the p-type property of TiO2. The IPCE values indicate that the absorption edges are red shifted with the increase of annealing temperatures.
      PubDate: Thu, 08 May 2014 00:00:00 +000
       
  • Magnetic and Transport Properties Based on Transition-Metal Compounds

    • PubDate: Wed, 07 May 2014 12:13:42 +000
       
  • Equivalent Circuit Analysis of Photovoltaic-Thermoelectric Hybrid Device
           with Different TE Module Structure

    • Abstract: Combining two different types of solar cells with different absorption bands into a hybrid cell is a very useful method to improve the utilization efficiency of solar energy. The experimental data of dye-sensitized solar cells (DSSCs) and thermoelectric generators (TEG) was simulated by equivalent circuit method, and some parameters of DSSCs were obtained. Then, the equivalent circuit model with the obtained parameters was used to optimize the structure design of photovoltaic- (PV-) thermoelectric (TE) hybrid devices. The output power first increases to a maximum and then decreases by increasing the TE prism size, and a smaller spacing between p-type prism and n-type prism of a TE p-n junction causes a higher output power of TEG and hybrid device. When the spacing between TE prisms is 15 μm and the optimal base side length of TE prism is 40 μm, the maximum theoretical efficiency reaches 24.6% according to the equivalent circuit analysis. This work would give some enlightenment for the development of high-performance PV-TE hybrid devices.
      PubDate: Wed, 07 May 2014 11:19:32 +000
       
  • First-Principles Study of the Structural Stability and Electronic and
           Elastic Properties of Helium in α-Zirconium

    • Abstract: First-principles calculations within density functional theory have been performed to investigate the behaviors of helium in α-zirconium. The most favorable interstitial site for He in -Zr is not an ordinary tetrahedral or octahedral site, but a basal octahedral site with a formation energy as low as 2.40 eV. The formation energy reduces to 1.25 eV in the presence of preexisting vacancies. The analysis on the density of states and the charge density has been carried out. In addition, the influences of He and small He-V complexes on the elastic properties have been studied. The He-V complexes have been found to greatly affect the elastic properties compared with He alone.
      PubDate: Mon, 05 May 2014 16:57:08 +000
       
  • Magnetic Properties of Well-Aligned ZnO Nanorod Arrays Grown by a Simple
           Hydrothermal Reaction

    • Abstract: Well-aligned ZnO nanorod arrays with room temperature ferromagnetism were prepared on glass substrate through hydrothermal method. The as-prepared nanorod arrays were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), photoluminescence (PL) spectrum, and magnetization measurements. The XRD and SEM results indicated that the ZnO nanorods are with the wurtzite structure and exhibit preferential (002) orientation with -axis perpendicular to the substrate surface. The PL results suggested that the possible defect in the as-prepared ZnO nanorod arrays might be , , or . The first-principles calculations reveal that the room temperature ferromagnetism may result from the defects present in the ZnO nanorod and the hybridization of the Zn 3d states with O 2p states is responsible for the half-metallic ferromagnetism in ZnO nanorod.
      PubDate: Tue, 29 Apr 2014 08:50:01 +000
       
  • Suppression of Brazier Effect in Multilayered Cylinders

    • Abstract: When a straight hollow tube having circular cross-section is bent uniformly into an arc, the cross-section tends to ovalize or flatten due to the in-plane stresses induced by bending; this ovalization phenomenon is called the Brazier effect. The present paper is aimed at theoretical formulation of the Brazier effect observed in multilayered cylinders, in which a set of thin hollow cylinders are stacked concentrically about the common axis. The results indicate that mechanical couplings between stacked cylinders are found to yield pronounced suppression of the cross-sectional ovalization. Numerical computations have been performed to measure the degree of suppression in a quantitative manner and to explore how it is affected by the variations in the bending curvature, the number of stacked cylinders, and the interlayer coupling strength.
      PubDate: Mon, 28 Apr 2014 09:15:55 +000
       
  • Nanoparticle Imaging with Polarization Interferometric Nonlinear Confocal
           Microscope

    • Abstract: Polarization interferometric nonlinear confocal microscope has been developed for single nanoparticle analysis of drug delivery system (DDS). The microscope is a system based on a low cost and low power continuous wave (CW) laser light source. Also, the microscope observed shape anisotropy of the 200 nm diameter nanoparticle. According to nanoparticle imaging and CTF (contrast transfer function) curve observation of the microscope, three-dimensional resolution of the microscope measured up to 10 nm.
      PubDate: Sun, 27 Apr 2014 00:00:00 +000
       
  • Improved Composite Gel Electrolyte by Layered Vermiculite for
           Quasi-Solid-State Dye-Sensitized Solar Cells

    • Abstract: A composite quasisolid electrolyte is prepared by adding a layered vermiculite (VMT) into the iodide/triiodide electrolyte including 4-tert-butylpyridine, which obviously improves the photovoltaic properties of quasisolid dye-sensitized solar cells (DSSCs). When adding 6 wt% VMT, the maximum photovoltaic conversion efficiency of 3.89% is obtained, which reaches more than two times greater than that without VMT. This enhancement effect is primarily explained by studying the Nyquist spectra, dark currents, and photovoltaic conversion efficiency.
      PubDate: Tue, 22 Apr 2014 13:07:32 +000
       
  • E-k Relation of Valence Band in Arbitrary Orientation/Typical Plane
           Uniaxially Strained

    • Abstract: Uniaxial strain technology is an effective way to improve the performance of the small size CMOS devices, by which carrier mobility can be enhanced. The E-k relation of the valence band in uniaxially strained Si is the theoretical basis for understanding and enhancing hole mobility. The solving procedure of the relation and its analytic expression were still lacking, and the compressive results of the valence band parameters in uniaxially strained Si were not found in the references. So, the E-k relation has been derived by taking strained Hamiltonian perturbation into account. And then the valence band parameters were obtained, including the energy levels at Γ point, the splitting energy, and hole effective masses. Our analytic models and quantized results will provide significant theoretical references for the understanding of the strained materials physics and its design.
      PubDate: Wed, 16 Apr 2014 08:33:20 +000
       
  • Synthetic Strategies and Applications of GaN Nanowires

    • Abstract: GaN is an important III-V semiconductor material with a direct band gap of 3.4 eV at 300 K. The wide direct band gap makes GaN an attractive material for various applications. GaN nanowires have demonstrated significant potential as fundamental building blocks for nanoelectronic and nanophotonic devices and also offer substantial promise for integrated nanosystems. In this paper, we provide a comprehensive review on the general synthetic strategies, characterizations, and applications of GaN nanowires. We first summarize several growth techniques of GaN nanowires. Subsequently, we discuss mechanisms involved to generate GaN nanowires from different synthetic schemes and conditions. Then we review some characterization methods of GaN nanowires. Finally, several kinds of main applications of GaN nanowires are discussed.
      PubDate: Tue, 15 Apr 2014 16:27:03 +000
       
  • Photocatalytic Reduction of CO2 to Methane on Pt/TiO2 Nanosheet Porous
           Film

    • Abstract: Anatase TiO2 nanosheet porous films were prepared by calcination of the orthorhombic titanic acid films at 400°C. They showed an excellent photocatalytic activity for CO2 photoreduction to methane, which should be related to their special porous structure and large Brunauer-Emmett-Teller (BET) surface area. In order to further improve the photocatalytic activity, Pt nanoparticles were loaded uniformly with the average size of 3-4 nm on TiO2 porous films by the photoreduction method. It was found that the loading of Pt expanded the light absorption ability of the porous film and improved the transformation efficiency of CO2 to methane. The conversion yield of CO2 to methane on Pt/TiO2 film reached 20.51 ppm/h·cm2. The Pt/TiO2 nanosheet porous film was characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), and ultraviolet-visible light diffuse reflectance spectra (UV-vis DRS). Moreover, the transient photocurrent-time curves showed that the Pt/TiO2 nanosheet porous film exhibited higher photocurrent, indicating that the higher separation efficiency of the photogenerated charge carriers was achieved.
      PubDate: Sun, 13 Apr 2014 16:32:53 +000
       
 
 
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