Design of metamaterial absorber and its applications for waveguide slot antenna
Spatial dispersion of pulse shaping system with high resolution based on the frequency comb
Sensitivity of Delta-P1 approximation model to second-order parameter
The sensitivity of the second-order parameter γ of the Henyey-Greenstein phase function based on the spatially-resolved diffuse reflectance within the two-point-source approximation to the Delta-P1 approximation model is studied, and the analytical expression of the sensitivity is derived. The results show that the analytic solution of the Delta-P1 approximation model for reflectance contains the second-order parameter γ of the scattering phase function compared with the diffusion approximation model, and the second-order parameter γ has significant influence (the extreme value greater than 30%) on the analytic solution for spatially-resolved diffuse reflectance with small source-detector separations (ρ< 1.5 mm) no matter whether the absorption is weak or strong. The research has theoretical significance for obtaining the optical information abour tissue with the second-order parameter γ.
Investigation on the characteristics of electromagnetic scattering from large-scale rough surface of layered medium
Research and discussion on the lock-in threshold variation of ring laser gyro
Theoretical studies on nonvolatile holographic recording for LiNbO3:Cu:Ce crystals
Dissipative dynamics of few-photon superposition states in optical microcavity
Effects of modulation of atomic injection and exit rate on spatial evolution of phase-dependent lasing without inversion gain and intensity in an open V-type system
Polarization stable vertical-cavity surface-emitting laser with surface sub-wavelength gratings
Supercontinuum enhancement and transfer induced by a plasma grating in air
Nonlinear phase noise analysis of long-haul interferometric fiber sensing system
Multiple-type solutions for multipole interface solitons in thermal nonlinear medium
A new approach to dealing with bidirectional reflectance of non-homogeneous atmosphere
Nonlinear absorption properties of Cu(II)meso-tetra(4-sulfonatopheny1) porphine in TiO2/SiO2 organic-inorganic gel using Z-scan technique
Sensitivity of spatially-resolved diffuse reflectance to optical parameters in the hybrid diffusion approximation
A new multi-wavelength two-way quantum key distribution system with a single optical source
Design and analysis of two-stage transmitted-reflected concentration PV/thermal system with spectral beam splitter
Study of collimator array based on single collimating lens
The generation and transmission research of the fan-shaped multi-beam intense relativistic electron beams
Layered elliptical-cylindrical acoustic cloaking design based on isotropic materials
Generation of negative pressure of underwater intensive acoustic pulse and cavitation bubble dynamics
Study of coupled fluid and solid for a hypersonic lending edge
Microscopic simulation on shock-induced micro-jet ejection from metal Al surface
Experimental study of spread characteristics of droplet impacting solid surface
Experiments on shock-absorbing capacity of granular matter under impact load
Electron-beam induced abnormal expansion in a silica-shelled gallium microball-nanotube structure (Retracted Article)
Under electron-beam irradiation of heteroshape-heteroscale structure of silica-shelled Ga microball-nanotube, an abnormally large and fast volume expansion of liquid Ga is observed. First, we analyze the processes and phenomena about experiment, and the abnormal expansion process can be regarded as a quasi-static process. Then in the framework of quasi-static thermodynamics, according to the Fourier heat conduction law the relative volume variation with temperature is further quantitatively discussed, and the relative expansion rate and expansion coefficient in system are obtained. At the same time it is found that abnormal expansion coefficient of system under electron-beam irradiation is 5-9 times the general thermal expansion coefficient. Finally, it is pointed out that the abnormal expansion is due to the gallium atom ionization effect and the retention effect resulting from a few electrons retaining in the liquid gallium system under electron-beam irradiation. In essence, both ionization effect and the retention effect make the particle densities of liquid systems increased dramatically, resulting in volume expansion abnormally large and fast of liquid Ga.
TEM study of GaN films on vicinal sapphire (0001) substrates by MOCVD
Quality properties and internal defects of unintentionally doped GaN films grown on 0.3° vicinal sapphire (0001) substrates by MOCVD are investigated by TEM. The results show that plenty of dislocations in the GaN films prepared on vicinal sapphire substrates are annihilated in the areas with a distance of 0.8 μm away from substrates, and that dislocations gather in the GaN films. Based on these phenomena, a mechanism for dislocation annihilation in the GaN film prepared on vicinal substrate is proposed, which is capable of explaining the fact that vicinal substrates are able to improve the qualities of GaN films.
The evolution of microstructure and mechanical properties of Ti/Al composite synthesized by accumulative roll-bonding
Improvement on performance of Si-based Ge PIN photodetector with Al/TaN electrode for n-type Ge contact
Relationship between liquid structure and property III——residual bond theoretical model
Based on the concept of residual bond, a physical model quantitatively describing the relationship between the melt structure and viscosity of metal is established by mathematical deduction, and the microscopic nature of viscosity is considered to be the evolution of the size d of the residual-bond structure of melt. Using this model, the kinematic viscosityies of the magnesium and aluminum melt in a certain region above the melting point are calculated, and the functional relations vMg=3.17×10-7+3.04×10-7·d and vAl=1.65×10-7+1.05×10-7·d are obtained, which accord with the experimental data measured by the method of crucible rotating oscillation damping. This model reveals the microscopic naturs of the micro-inhomogeneity and viscosity of the melt structure from the view of chemical bond, which provides a new way to calculate the viscosity of melt and is of significance for understanding the relationship between microstructure and macroscopic properties of liquid metal.
Problem and modification to the equation of state for liquid and solid-liquid mixed phase in Grover model
Effect of thermal-pressure treatment on magnetoelectric transport in Nd0.7Sr0.3MnO3 ceramics
The Nd0.7Sr0.3MnO3 compounds are treated at a thermal pressure (HTP) of temperature 1273 K and pressure 9 GPa. The results show that the crystal structure and space group of samples keep unchanged while the lattice and structural parameters, especially the microscopic structure change remarkably, which produces significant influence on magnetoelectric transport of the Nd0.7Sr0.3MnO3 ceramic. For electrical transport of the HTP sample, no electroresistance (ER) effect occurs when loaded current is less than 1.5 mA, however, an ER effect around 200% takes place when the loaded current goes up to more than 1.5 mA. Interestingly, the peak at ρ-T curve disappears by replacing a platform, which can return to a peak if a magnetic field is applied again. The formation of intergranular phase and insulating behaviour of sample under thermal pressure condition are suggested to be responsible for the unique transport properties.
The phonon effect of polaron and qubit in spherical shell quantum dot
The simulation of precipitate splitting in alloy (Ⅰ): segmentation mechanism
First-principle calculations of elastic, electronic and thermodynamic properties of TiC under high pressure
The interfacial electronic structures at FePc/TiO2(110) and FePc/C60 interface
Research of dimer diffusion and dissociation on Cu surfaces
Influence of B doping on structure and properties of Ti Thin Film
Confinement effect and interface effects on the thermoelectric properties of nano-ceramics: theoretical study
Numerical investigation of the metal-insulator-metal waveguide filter based on the arc-shaped resonator
Dielectric spectra of ZnO varistor ceramics
The passivation of Al2O3 and its applications in the crystalline silicon solar cell
Investigation of the photovoltaic performance of n-ZnO:Al/i-ZnO/n-CdS/p-Cu2ZnSnS4 solar cell
Light-induced magnetoconductance effect in organic light-emitting diodes
Organic light-emitting diode with a structure of ITO/CuPc/NPB/Alq3/LiF/Al is fabricated. The excitons of the device are produced by laser irradiation using two kinds of laser beams which are at 442 nm and 325 nm, and the evolutions of the excitons are controlled by a small bias (which is either positive or negative, and ensures that the device does not turn on). The photo-induced magneto-conductance (PIMC), which is the dark current of the device showing no magnetic response at a small bias, is also measured at the same time. It is found that unlike the magneto-conductance in the electrical injection case, the PIMC presents significantly different results at the positive and negative small bias. The PIMC of the device increases rapidly in a range of 0-40 mT at a small forward bias, then increases slowly with the further increase of magnetic field, and finally becomes saturated gradually. But in the case of small reverse bias, although the PIMC of the device also first increases rapidly with the increase of magnetic field (0-40 mT), but it decreases after its maximum value has been reached. By using a composite model of electron-hole pairs and the theory of hyperfine interaction, the PIMC effect at the forward bias can be explained by analyzing the effects of the applied magnetic field on the micro-processes of the light-generated carrier of the device. When the device is in the case of reverse bias, due to the fact that the relationship of the energy-band of each organic layer provides the necessary conditions for the interactions between exciton and charge, the decrease of PIMC in high magnetic-fields can be attributed to the mechanism of reaction between triplet exciton and charge.
Structural and electronic properties of Al-doped spinel LiMn2O4
The structural and electronic properties of spinel LiMn2O4 and its Al doping system LiAl0.125Mn1.875O4 are investigated within the density functional theory in both the generalized gradient approximation (GGA) and the GGA with Hubbard U correction (GGA+U). The results from the GGA method suggest that LiMn2O4 has a cubic structure and the valences of Mn ions are all +3.5, which is unable to explain the Jahn-Teller distortions in the material. The band structure of LiMn2O4 predicted by the GGA method is also inconsistent with experimental result. With the GGA+U method, the low temperature structures of LiMn2O4 and its Al doping system LiAl0.125 Mn1.875O4 are shown to be orthogonal, the two different valence states of Mn, i.e., Mn3+/Mn4+ ions, are then determined, which is then able to explain the Jahn-Teller distortion in octahedron Mn3+O6 and the non-existence of distortion in octahedron Mn4+O6. These results are in good accordance with experimental data. Their band structures by GGA+U calculations are also consistent with experimental results. The GGA+U calculations on the LiAl0.125Mn1.875O4 indicate that with the replacement of an Mn by Al, the crystal structure and electronic properties are not significantly changed, but the Jahn-Teller distortion in octahedron Al3+O6 can be effectively eliminated, which could improve the performance of the anode materials based on LiMn2O4. The phenomenon is in consistent with the electrochemical experiments.
The nonreciprocal of second harmonic generation with dielectric/antiferromagnetic/dielectric structure in Voigt geometry
Properties and order-disorder competition of spin-1/2 XY model in the ferrimagnetic diamond chain
The coercivity of the high temperature magnets Sm(CobalFe0.1Cu0.1Zr0.033)6.9 alloys
Dynamic behaviors of domain wall in FM/AFM bilayers
Study on the variation of static dielectric constant with temperature and the corresponding orientational correlation in polar liquids by using Weiss's molecular field theory
Theoretical analysis of response characteristics for the large exponential-doping transmission-mode GaAs photocathodes
A new-type GaAs photocathode with ultrafast time response, that is, the large exponential-doping transmission-mode GaAs photocathode, is discussed in detail. The response characteristics, including quantum yield, time and spatial resolution, are numerically simulated. The analysis results show that the transit response time of the photo-excited electrons for the GaAs photocathode is extremely shortened, because the built-in electric field in GaAs layer formed by the large exponential-doping mode is benefitcial to the photoelectron transport process of GaAs photocathodes. The response time can reach about 10 ps when the thickness of GaAs dgorption layer is around, which shows that the novel NEA cathode has a better feature of temporal response than that of traditional GaAs photocathode. In addition, the quantum yield will reach ～10%-20% in the whole special response range, and the spatial resolution is improved obviously. The analysis results indicate that with high quantum efficiency guaranteed, the large exponential-doping NEA cathode overcomes the limitation of time response of traditional GaAs NEA cathode and improves the spatial resolution, which indicates that the new NEA cathode is expected to meet the demands of high-speed device and photoelectron device, and promote the further development and applications of NEA cathodes.
Preparation and characteristic of phase transition vanadium oxide thin films by rapid thermal process
Metal-insulator phase transition VOX thin film is fabricated on a Si <100> substrate after the metal V thin film, prepared by direct current facing targets magnetron sputtering has been rapidly thermally treated first in pure oxygen environment and then in pure nitrogen environment. The thermal treatment conditions are 430℃/40 s, 450℃/40 s, 470℃/40 s, 450℃/30 s, 450℃/50 s in pure oxygen environment and 500℃/15 s in pure nitrogen environment. XRD, XPS, AFM and SEM are imployed to analyze the crystalline structure, valentstate and the components, morphology of the thin film. The electrical and optical characteristic of the thin film are analyzed by the Four-point probe method and THz time domain spectrum technology. Results reveal that after 450℃/40 s rapid thermal treatment in pure oxygen environment the metal V thin film turns into VOX thin film which has low properties of phase transition. Before and after heating, the change of resistivity reaches 2 orders of magnitude and the range of the THz transmission intensity shows smooth change. In order to improve the properties of phase transition, the VOX thin film is treated by 500℃/15 s rapid thermal process in pure nitrogen environment. After that, we find that the thin film shows a good phase transition performance, accompanied by a sheet square resistance drop of above 3 orders of magnitude and a 56.33% reduction in THz transmission intensity.
Aberrations in holographic array optical tweezers corrected with Zernike polynomials
A new method of obtaining perturbation vertical profiles in estimating the atmosphere gravity wave parameters
The critical warning research of the mean time series mutations based on Logistic model
A modified method to configure the parameters of the bilateral filtering for synthetic aperture radar image speckle reduction
Statistical modeling arbitrary diversitiy multi-input multi-output systems
Study on derivation and optimization algorithm about thin plate bending large deformation higher-order nonlinear partial differential equations
Study on gradually-varying cavity for a gyrotron
The evolution of three-body entanglement in the system of atoms interacting with coupled cavities
On the schemes of cavity photon elimination in circuit-quantum electrodynamics systems
The tunneling phenomena of the Fermi superfluid gases in unitarity by manipulating the Fermi-Fermi scattering length
Weak signal detection based on chaos and stochastic resonance
Application of Chen's system to detecting weak harmonic signals
Modified function projective lag synchronization for multi-scroll chaotic system with unknown disturbances
Field programmable gate array-based chaotic encryption system design and hardware realization of cell phone short message
Peaked soliton solutions and interaction between solitons for the extended (2+1)-dimensional shallow water wave equation
Fractal eroded safe basins in a forced Holmes-Duffing system and its control by delayed velocity feedback
Frequency measurement of dual frequency He-Ne laser based on a femtosecond optical frequency comb
Method on double-pass acousto-optic frequency shifter in absolute distance measurement using Fabry-Pérot interferometry
The influence of ionization efficiency on the multiply charged ions produced by laser-clusters interaction
Strain effect on the intercalation potential of the layered Mn-contained lithium ion batteries cathode materials: a first principles method
The strain effects on the intercalation potentials of LiMnO2 and Li2MnO3 are investigated by the first principles method, and the relationship between the intercalation potential and the strain is given in the form of elastic response. All the modes of strain reduce the intercalation potential and the effect is anisotropic. Most of the single modes reduce the potential by less than 0.1 V when the strains are 5%. The bonding between the host layers is rather sensitive to the strain perpendicular to the host layer when the lithium vacancy left by lithium extraction is in the lithium layer, thus that strain brings more reduction to the intercalation potential; whereas for the Li2MnO3 system when lithium is extracted form the transition metal layer, the strain along the host layer brings more reduction to the potential. For the Li2MnO3-stabilized LiMO2 (M=Mn, Ni, Co) solid solution system, the strain can keep the voltage of the high potential charging stage lower than the cut-off voltage, and open up the migrating pathway of lithium in the transition metal layer, therefore the charging can last a long time and larger charging capacity is achieved.
Simulation of optical potential of Gaussian laser standing wave by diffraction of straight edge
Experimental investigation on ionized ultracold molecules formed in a magneto-optical trap by time-of-flight mass spectroscopy
We use time-of-flight mass spectroscopy to detect the ultracold ground state Cs2 molecules formed directly by a photoassociation due to the trapping laser beams and repumping laser beam in a magneto-optical trap. We investigate the dependences of the Cs2+ intensity on operating voltage of micro-channel-plate, accelerating field intensity and duration time of the accelerating field. The experimental results are consistent with theoretical fitting. We obtain the best optimal parameters suited to our experimental condition, which is important for the future experiment on ultracold molecule photoassociation and photoionization spectroscopy.
The study of particle direct loss in tokamak
Research of coherence between driven-laser beams and its influence on backscatter
Previous studies have shown that the technology of beam smoothing may effectively control parameter instabilities within the laser-plasma interaction, and greatly reduce stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS). However, the recent experimental results on NIF revealed a much higher SBS and SRS than expected, one possible reason is due to the coherence between incident laser beams. In our research, two laser beams from "Shenguang II" facility are employed to irradiate an Au plate target, the energy and spectra of the backscattered light are measured in different coherent conditions. The results show that the driven-laser beams strongly interfere with each other, and usually the backscatter becomes strong gradually with the increase of coherent degree between the incident beams.
Inactivation of A549 cancer cells by a helium-oxygen plasma needle
An inactivation mechanism of A549 cancer cells is studied by using a dielectric barrier discharge (DBD) plasma needle. The influence of oxygen concentration, which is injected into helium plasma afterglow region through a stainless steel tube, is investigated. The neutral red uptake assay provides a qualitative observation of morphological differences between the dead cells and the viable cells after plasma treatment and a quantitative estimation of cell viability under different conditions. In the treatment process at a fixed power of 24 W, the inactivation efficiency of helium-oxygen plasma depends mainly on the exposure time and percentage of added oxygen in helium plasma. Experimental results show that the best parameters of the process are 150 s treatment time, 800 mL/min He with 3% O2 addition and separation of needle-to-sample 3 mm. According to the helium-oxygen emission spectra of the plasma jet, it is concluded that the reactive species (for example, OH and O) in the helium-oxygen plasma play a major role in the cell deactivation.
3D numerical study on volume production efficiency of J-PARC multicusp ion source
Numerical optimization of volume production efficiency of the JAERI 10 A ion source