Progress in the blend stacked structure of organic solar cells
Organic solar cells have received extensive attention due to their light weight, low cost, flexible. Because a single organic material absorbs only part of the sun light, laminated structure of solar cell, consisting of different absorption band gaps of organic material through the middle connecting layer, can both cover a larger part of the solar flux, and improve the circuit voltage or short circuit current of the solar cells. In this paper, the recent progress of the blend laminated structure polymer solar cells is summarized. Structures, principles and performances of a variety of laminated organic solar cells are introduced. The present status of research and existing problems of the blend laminated structure polymer solar cells are described, which provides valuable referesce for the study of high-performance organic solar cells.
Process in preparation of metal-catalyzed graphene
Graphene, which is regarded as a new carbon material, has attracted much attention of scientists. Graphene holds the promise for applications in optoelectronics and microelectronics, owing to many unique physical and chemical properties. The large-scale applications are restricted by controllable synthesis of large-size graphene. In this paper we present the advantages and disadvantages of preparation processes of graphene. The recent advances in the process of metal-catalyzed graphene in terms of lay number control and large area synthesis are discussed. The graphene prepared by metal-catalyzed solid carbon source has large area and high quality and is thin and homogeneous. We review the latest progress in graphene transformation mechanism, point out the limitations of current study and prospect the future development in the graphene transformation mechanism.
Design and study of the two-dimensional ellptical scattering-shifting cloak
Influence of the washer-rod structure on high frequency characteristics of wide-gap klystron cavity
Study of extended interaction oscillator with folded waveguide in sub-terahertz band
In this paper, a folded waveguide is adopted as a slow wave structure (SWS) of the extended interaction oscillator (EIO). An EIO with frequency 105 GHz in sub-Terahertz band is studied in detail, including the dispersion relation and the impedance of the SWS, and the variation of starting current with the period number, which provides an effective way to reduce starting current. On this basis, from the PIC simulation studies are discussed the EIO beam-wave interaction and output characteristics under the operation modes of low current continuous wave and strong current pulse. Further, the tuning characteristic of the EIO is analyzed, showing that output power reaches 26-50 W and the corresponding frequency range is 105.26-105.31 GHz. By EDM technology two fabrication methods of the SWS are investigated and the transmission properties of the SWS and the window are tested indicating that they are in good agreement with the simulation results.
All-optical diode in mid-infrared waveband based on self-phase modulation effect in silicon ring resonator
The characteristics of elliptical optical soliton in anisotropic medium
Experimental studies of slow wave based on the surface waves in a two-dimensional metamaterials waveguide
Decoherence effect of target roughness in synthetic aperture ladar
Spectral zooming birefringent imaging spectrometer
Experimental research of tip/tilt control of a multi-channel fiber-laser array
High-quality digital image-plane micro-holographic system with the same wavefront curvature of reference and object wave
The digital image-plane holographic microscopy which has the same curvature radius in the object light path and the reference light path is studied for the first time to our knowledge. The configuration of this setup is analyzed and built. The point spread function of this system is derived. The factors corresponding to the imaging resolution and the imaging characteristics of this system are analyzed. The method to correct the linear phase distortion in the reconstructed optical field is discussed. The results show that this system has the largest information content, and the imaging resolution of the system is dependent on the numerical aperture of the microscope objective (MO) and on the CCD pixel size, but independent of the photosensitive surface size of the CCD. All frequency components of each point in the object wave which has passed through the MO can completely be recorded and reconstructed. And the size of illuminated region of object has no influence on the recording condition and the quality of the reconstructed image. The digital image-plane holographic microscopy with the same curvature radius in the object light path and the reference light path is an optimized holographic recording system, which can achieve high-quality imaging. The experimental results demonstrate the correctness of the theoretical analysis.
Isochronal chaos synchronization of a chain mutually coupled semiconductor lasers
Mode-locked double-clad fiber laser with a carbon nanotubes saturable absorber
Three-dimensional thermal effects of the diode-pumped Nd:YVO4 slab
Method of designing astigmatic compensation cavity for mode-locked laser based on propagation circle
Investigation of tunable coherent XUV light source by high harmonics generation using intense femtosecond laser pulses in Ne
Research on magnetic control mechanism of four-wave mixing in highly nonlinear fiber
Characteristics of laser transmission in different types of aerosols
Design and analysis of guided-mode resonance filter containing an absentee layer with an antireflective surface
Transmission control of nonautonomous optical rogue waves in nonlinear optical media
Field-tracing based numerical simulation technique for the investigation of ultra-small self-focusing optical fiber probe
Design of tunable optical power splitter based on thermal expansion effect
Acoustic scattering from a finite quasi-periodic bulkhead cylindrical shell
The response property of one kind of factional-order linear system excited by different periodical signals
Energy dissipation of a granular system under vertical vibration
Analytical approximations for capillary flow in interior corners of infinite long cylinder under microgravity
Probability density function of temperature in a circular-cylinder turbulent wake
In this article, we report on an experimental research on the probability density function (PDF) of temperature measured in the wake of a circular cylinder slightly heated and its relationships with the turbulent mixedness under different Reynolds numbers (1200-8600). The temperature is measured by a probe of cold-wire with 0.63-μm in diameter. Results show that the temperature PDF varies significantly with location in the wake. An increase in Reynolds number speeds up this variation, particularly accelerates the evolution from totally non-Gaussianity to near-Gaussianity along the wake centreline.
Lattice Boltzmann modeling of particle inertial migration in a curved channel
A three-dimensional coupled model for particle inertial migration in the presence of micro flows is proposed and implemented. In the present model, the kinetic theory based lattice Boltzmann method is used to describe the fluid flows, and the Newton dynamics equation based model is used to describe the translation and rotation of the particle. The fluid and particle model are coupled by the LBM bounceback scheme based moving boundary method. The processes of particle settlement under gravity and particle rotation in the condition of Couette flow take place. The reliability of the present model and algorithm is validated through comparisons between the present simulation and the benchmark tests in the literature. The simulations of particle migration with various radii in an annular curved channel are performed, and the classic velocity distribution of the secondary flow in the channel cross-section is reproduced successfully. The mechanism of the particle radius influencing the particle equilibrium position in the curved channel is discussed. The results show that the particle equilibrium position in the curved channel will approach to the channel inner wall with the increase of radius. The present model is of important value for detailed study of the particle dynamics in micro flows as well as for the design and development of new micro fluidic particle selective chips and devices.
Reynolds number effect on passive-scalar characteristics of a circular cylinder wake
Analysis of liquid sheet and jet flow mechanism after droplet impinging onto liquid film
Study on the energy dissipation of macroscopic traffic models
Thermal rectification and phonon scattering in silicon nanofilm with triangle hole
AC properties of Pr0.7Ca0.3MnO3 ceramics
Ceramic Pr1-xCaxMnO3(x=0.3) samples are prepared by solid-state reaction and measured using direct current (DC) and alternating current (AC) methods in different magnetic and electrical fields. A Curie temperature of 150 K is determined by I-V measurements in field for Pr0.7Ca0.3MnO3, which is consistent with that from vibrating sample magnetometer (VSM). The AC measurement shows that the grain boundary resistance reduces with magnetic field increasing, while the grain almost keeps unchanged, and it indicates that the colossal magnetoresistance (CMR) effect in low field mainly comes from the grain boundary for the Pr0.7Ca0.3MnO3 ceramic. The barrier height of grain boundary is 117 meV for the Pr0.7Ca0.3MnO3 ceramic, obtained by fitting the temperature spectrum of impedance, and it is well coincident with that from fitting the R-T data. A "trap state" model is proposed to explain all the measured data.
Characterization of TiB2 synthesized at high pressure and high temperature
Thermal conductivity of metallic nanoparticle
Modulational instabilities of two-component Bose-Einstein condensates in the optical lattices
Temperature window of the (Al0.1Ga0.9)0.5In0.5P growth by MOCVD
Mn-doping effects on structural, optical and magnetic properties of BaSn1-xMnxO3
Polycrystalline bulk samples of BaSn1-xMnxO3 with x=0, 0.05, 0.10 and 0.13 are prepared by the conventional solid state reaction method. The effects of Mn concentration on crystal structural, optical and magnetic properties of BaSn1-xMnxO3 are investigated systematically. Powder X-ray diffraction (XRD) shows that each of these compounds presens a perovskite structure (with the space group Pm3m) without the secondary crystalline phase. The Mn ions take the Sn sites which is revealed by the XRD, diffusion reflectance spectrum (DRS) and Raman scattering. With the increase of doping level x, the optical absorption edge shifts towards higher wavelength and is smoothened gradually, meanwhile the Raman spectrum shows that Raman mode is also changed. The photoluminescence spectrum under magnetic field shows that near-infrared luminescence is probably related to Sn ions. The magnetization measurement demonstrates that Mn-doped BaSnO3 system exhibits ferromagnetism at low temperature, which can be explained by the F-center exchange (FCE) mechanism.
Crystal structures and optical properties of(Fe, Co)-codoped ZnO thin films
The Fe, Co-codoped Zn0.9FexCo0.1-xO (x=0, 0.03, 0.05, 0.07) thin films are fabricated on the glass substrates by sol-gel method. The surface morphologies, crystal structures, elements and optical properties of the films are investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), X ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectrum. The XRD results reveal that all the ZnO films are of wurtzite structure. The diffraction peaks of the clusters, oxide or other impurity phase related to Fe and Co are not observed in the samples. This indicates that codoped is beneficial to the improvement on the dispersion of Fe or Co in ZnO. XPS results reveal that Co elements exist as Co2+, Fe elements exist as Fe2+ and Fe3+, but the increase of relative concentration of Fe leads to the increase of Fe3+ content. The ultraviolet emission peak and blue double emission are observed in the PL spectra of all the samples. Compared with the undoped ZnO film, the Co-codoped ZnO film has a blue shift of ultraviolet emission peak of Fe, the unchanged position of the blue double emission peak, and the weakened luminous intensity. Moreover, the green luminescence peak of the doped ZnO film almost disappears. Finally, the luminescence mechanisms of Fe, Co-codoped ZnO films are discussed by combining the microstructures and compositions of the samples.
Determination of photoelectric current by voltage between anode and cathode, intensity and frequency of light
Modulation of nonlinear coupling on the synchronization induced by linear coupling
Terahertz dual air core fiber directional coupler
Empirical study on scaling of human behaviors in e-commerce
Approximate symmetry reduction for initial-value problem of perturbed diffusion equations
In this paper, the approximate symmetry reduction for the initial-value problem of perturbed diffusion equations with source term is studied by the approximate generalized conditional symmetry. The classification of governing equations is given, and the Cauchy problem of partial differential equations is reduced to initial-value problem of ordinary differential equations. Finally, the approximate solution is obtained by solving the reduced system of equations.
Performance of closed-loop control of epileptiform spikes in neural mass models
Neural mass models can produce electroencephalography (EEG) like signals corresponding to interical, pre-ictal and ictal activities. In this paper, a novel closed-loop feedback control strategy based on algebraic estimation is proposed to eliminate epileptiform spikes in neural mass models. Algebraic estimation plays a role in observing the states of the model in order to construct the controller. For a network of coupled neural populations, the characteristics regarding the closed-loop feedback control strategy, including the relationship between the type of controlled populations and the ability of eliminating epileptiform spikes, the relationship between the number of controlled populations and control energy, the relationship between the model parameters and control energy, are determined by numerical simulations. The purpose is to establish the rules for the proper control of eliminating epileptiform spikes with as less control energy as possible. Moreover, the proposed control-loop control strategy is compared with a direct proportional feedback control strategy by numerical simulations. It is shown that the use of algebraic estimation makes a reduction of control energy.
Study of directed networks-based Email virus propagation model and its concussion attractor
According to directed Email networks and the spread characteristics of Email virus, we study the behavior of the virus shock propagation in Email networks by using the mean field method to build delay differential equation model of viral spread. Then, the sufficient condition about the existence of shock solution's global attractor is given in theory. The existence and control of attractor are proved by numerical experiments. Our research indicates that spread probability between subgraphs determines the existence of attractor, and effective rate of spread determines the amplitude of attractor. Therefore these two parameters are significant in prediction of the scale of viral spread in networks.
Key nodes in complex networks identified by multi-attribute decision-making method
An ameliorative algorithm of two-dimensional Poisson equation based on genetic parallel successive over-relaxation method
Dynamic scaling behavior of the space-fractional stochastic growth equation with correlated noise
Problem and analysis of stability decidable theory for a class of fractional order nonlinear system
Chaos analysis of the conic in planar unit area
The oscillation and bifurcation of a switching system composed of jump circuits
Parameter-adjusted stochastic resonance of first-order linear system
Cascade chaos and its dynamic characteristics
Design and implementation of an arbitrary poincare plane section circuit in three-dimensional space
Oscillations and non-smooth bifurcation analysis of Chen system with periodic switches
Synchronization of "Hopf/homoclinic" bursting with "SubHopf/homoclinic" bursting
Algorithm for finding horseshoes in three-dimensional hyperchaotic maps and its application
Dynamics analysis and synchronization of T chaotic system with its circuit simulation
A family of four-dimensional multi-wing chaotic system and its circuit implementation
Spatiotemporal chaos synchronization of complex networks by Backstepping design
Spatiotemporal chaos synchronization of complex networks by Backstepping design is investigated. Backstepping design is extended from synchronization between two chaotic systems to the synchronization of complex network constituted spatiotemporal chaotic systems. The relation between the configuration coefficient and the control gain is identified according to the stability theory. When the control input is added to any node of the network, the network synchronization is realized. Furthermore, simulation is made to verify the effectiveness of the synchronization mechanism.
Synchronization with different structures of uncertain chaotic system
A hybrid optimization approach to design of compact self-shielded super conducting magnetic resonance imaging magnet system
Measurements and analyses of uranium reaction rates on a depleted uranium shell with D-T neutrons
Effect of rotational excitation of NO on the stereodynamics for the reaction N(4S)+NO(X2Π)→N2(X3Σg-)+O(3P)
Theoretical study on polarities and spectrum properties of WnNim (n+m=8) clusters
Particle-in-cell simulation of corona discharge in low pressure in stepped impedance transformer
Research on coupling characteristics of low hybrid wave in the presence of electron cyclotron wave in Tokamak
The mechanism of effect of lens-to-sample distance on laser-induced plasma
Influence of gas flow on the size and crystal of silicon nanoparticle produced by laser deposition in low pressure
Numerical study of double tearing mode instability in viscous plasma
The MCC numerical algorithm of the extraction of the surface-produced negative hydrogen ions
Structural and optical characterization of film deposited by pulsed plasma thruster plume
Quasi-geostrophic theory and its application based on baroclinic two-layer model
The quasi-geostrophic theory is the theoretical basis of the short-term weather forecast. Quasi-geostrophic motion equations of mid-latitude synoptic -scale movement are the core of quasi-geostrophic theory. Based on baroclinic two-layer model, quasi-geostrophic potential tendency equation and vertical motion equation can more clearly explain the movement and development of upper and surface weather systems. The movement of 500 hPa upper trough depends on the vorticity advection of 500 hPa, its development is determined by 500 hPa vorticity advection and differential vorticity advection between 250 and 750 hPa . The movement and development of cyclone depend on the positive temperature advection at 500 hPa and differential vorticity advection between 250 and 750 hPa. A case of snoptic system evolution demonstrates that quasi-geostrophic theory based on baroclinic two-layer model is conducive to the quick recognition of the characteristics of mid-latitude synoptic scale baroclinic development system, the understanding of the objective law of the development of the weather systems and the physical basis of numerical products.
Distribution characteristics of lightning electromagnetic pulsed fields under the ground
A study of seasonal fctors impact on climate networks
Smith fuzzy control of teleoperation rendezvous with variable time delay