The simulated and measured electric field distributions along the separated function radio frequency quadrupoles(SFRFQ) are presented in this paper. Based on the simulations, the parameters of flake-electrode and the effective gap voltage gain have been optimized. As a design example, one set of SFRFQ electrode with 5 periods and inter-electrode voltage 70 kV is designed to accelerate O+ from 1MeV...
By using the function and equation transformations,a coupled linear second-order differential equations are reduced to a nonlinear first-order Elliptic equation. And the analytical solutions to coupled transformations that include first-order and second-order transformations are given.The special approximate solution to a superconductivity question derived from a reference is reformed by using the...
A general approach to the construction of conservation laws for nonholonomic nonconservative dynamical systems in the event space was presented. Firstly, the differential equations of notion of systems are written, and the definition of integrating factors is given. Next, the necessary conditions for the existence of the conserved quantities are studied in detail. Finally, the existence theorem an...
The purpose of this paper is to study local energy integral for the Birkhoffian systems. The condition under which there exists the integral in the Birkhoffian systems is obtained. Two examples are given to illustrate the application of the result.
The Mei symmetry, i.e. the form invariance, of an Emden system is studied. The definition and determining equation of Mei symmetry in the Emden system are given. The relations between the Mei symmetry,the Lie symmetry and the Noether symmetry are studied, and the conserved quantities of the Emden system are obtained. An example is given to illustrate the application of the results.
Symmetry theory of the generalized Hamilton-Tabarrok-Leech’s canonical equations is presented. The differential equations of motion of systems are written. The Noether symmetry, the form invariance and the Lie symmetry of systems are studied, and the corresponding conserved quantities are found. Finally, an example is given to illustrate the application of the results.
Seeking for higher-dimensional integrable models is important in nonlinear science. By using the infinite dimensions Virasoro symmetry subalgebra[σ(f1),σ(f2)]=σ(f′1f2-f′2f1) and prolongation theory, many higher-dimensional models can be derived. By means of a concrete realization, some higher-dimensional differential integrable models with infinite dimensions Virasoro symmetry subalgebra can be ob...
Using an entended Riccati mapping approach, we discuss the related Schr?dinger system and obtain the new exact solutions. Based on the derived solutions, the soliton-impulse and temporal-soliton and the interaction between solitons were constructed in this paper.
By constructing two new Riccati equations and using the generalized Riccati method, we simplified the form and enriched the general results.Using Mathematica software, exact solutions of the variable coefficient combined KdV equation with forced term are obtained, including many kinds of solitary-wave-like solutions,guasi-periodical solutions and solitary wave solutions with variable speed.
In this paper, we exploit two-mode model to investigate the influence of quantum fluctuation on the self-trapping of the Bose-Einstein Condensate(BEC). We found that, even for the finite number of particles, the transition to self-trapping is still observed.In particular, because of the quantum fluctuation due to the finite number of particles, the critical phenomenon becomes fuzzily: the smaller ...
Antisymmetrizing the actions of hand triple contained in volume operator and grasping on the segments rooting through any-valent vortex of spin netwok, and using the binor identity, a proof is given that all these actions are eigenactions with eigenvalue -2. A systematic algebraic method to calculate the eigenvalues of volume operator for any-valent vortices is given, and the general and algebraic...
The thermodynamic quantities of massless scalar, neutrino, electromagnetic, massless Rarita-Schwinger and gravitational fields near the general spherically symmetric static black holes are investigated by using the modified equation of state density due to the generalized uncertainty relation. It is shown that the thermodynamic quantities depend not only on the characteristic of the black hole but...
By evaporative cooling in QUIC trap, Bose-Einstein condensate (BEC) was achieved with 2×105 87Rb atoms in |F=2, mF=2〉 state. We have demonstrated the criterion of BEC transition by the variation of the axial size of the atoms in tight confinement, and observed phase transition from thermal atomic gases to Bose-Einstein condensate, and measured the shift of aspect ratio of BEC during free expansion...
In this paper, a simple infinite dimensional system (time-delayed van der Pol’s electromagnetic system) with rigorous solution is developed. Based on Poincaré mapping of the right-traveling voltage wave at the left end of the transmission line (x=0), the phenomena of bifurcations and chaos are investigated with the variation of system parameters E and λ. Numerical results show that there are very ...
Based on a simple infinite dimensional electromagnetic system consisting of a linear lossless transmission line in combination with a nonlinear boundary condition, the local map of backward voltage wave is established by using the traveling wave theory. The numerical simulation results show rich spatiotemporal nonlinear phenomena in the voltage wave on the lossless transmission line. The pattern d...
EMI of the switching-converter is decided by the spectrum of the PWM waveform. There is great theoretical and practical meaning to quantify and analysis them. This paper takes the PWM drive waveform as a time series of processes or events. Based on the analysis of the periodic frequency- spreading, statistical theory is applied to analyze the probability density function, characteristic function, ...
The role of inhibitory self-connection in a second order recurrent neural network with delays has been investigated. A sufficient condition is proposed to guarantee the global asymptotical stability of the equilibrium point for the delayed neural network. The results indicate that an unstable neural network without inhibitory interconnections can be asymptotically stabilized to a unique equilibriu...
Based on Lyapunov stability theory, a new method combining feedback control and adaptive control is proposed for the synchronization between two different chaotic systems. This method can be applied to solve synchronization problems of several classes of chaotic systems, e.g., Lorenz system, Chen system, Lü system, Liu system, and R?ssler system. It offers a general way of choice for the controlle...
In this paper, a new one-way Hash function is proposed based on chaotic neural network. With the neural network with piecewise linear chaotic map as the output function, the key generation function based on spatiotemporal chaotic system are used to realized the data confusion and diffusion. By the cipher block chaining mode, the proposed method can produce 128-bit Hash value for plaintext with arb...
In this paper, the problem of finite-time synchronization is proposed. Terminal slide mode control is combined with chaos synchronization. Chaos synchronization is regarded as tracking problem in control system. Sufficient condition for constructing Terminal slide mode by introducing nonlinear function into linear slide mode function is given. Corresponding the Terminal slide mode controller is gi...
An algorithm for one-way Hash function construction based on tangent-delay ellipse reflecting cavity-map system (TD-ERCS) is proposed in this paper. In the algorithm, the plaintext dealt with is first transformed into a systemic parameter sequence linearly, and then TD-ERCS is iterated in order of the parameter sequence directly, the final Hash value of 160 bits is obtained by means of the nonline...
This paper proposes a novel circuit design and implementation approach of generating multi-scroll chaotic attractors from high-order Jerk systems. According to high-order Jerk equations, multi-scroll high-order general Jerk circuits are designed by constructing a sequence of step functions with parameter control. The prominent feature for this kind of circuit design method is self-unified and in a...
Facing to the ferroresonance over voltage of neutral grounded power system, an improved learning algorithm based on RBF neural networks is used to control the chaos system. The algorithm optimizes the object function to derive learning rule of central vectors, and uses the clustering function of network hidden layers.It improves the regression and learning ability of neural networks. The academic ...
We investigate the exact quantum motions of two ions in a two-dimensional Paul trap. When the Coulomb-correlation of the system is considered, we obtain a set of exact solutions of the system and the corresponding perturbed solutions, containing the exact discrete eigenstates and eigenenergies, and the approximate piecewise continuous spectra and the band structure. Taking several quantum states w...
Fundamental principles of high-frequency chaos generation and synchronization in Er-doped fiber ring lasers are analyzed. The experimental configuration for generating wavelength-tunable chaos is proposed, and high-frequency chaotic lasers at different wavelengths are generated. Synchronization between the chaos generated in the receiver laser and the chaos transmitted over 1 km that is generated ...
The conditions of constraint are treated by means of the mean constraint plane and the mean jump equation, in which the method of the Chebyshev polynomial approximation, previously used to explore period-doubling bifurcation of stochastic smooth systems, is applied to stochastic non-smooth systems. Numerical simulations show that period-doubling bifurcation exists in stochastic Duffing one-sided ...
Amorphous BCN was prepared by ball milling the mixture of graphite and hexagonal BN for 120h, and then annealed for 45 min. at 1600K under 4.5GPa. The XRD,TEM and Raman scattering measurement indicated that the as-prepared sample consists of hexagonal phase Ⅰ with lattice constants a1=0.2551nm and c1=0.6716nm and hexagonal phase Ⅱ with lattice constants a2=1.2360nm and c2=0.8570nm, of which the he...
The calculation of Dirac operator determinant in non-Abelian gauge theory is generalized from only containing hard fermion mass to that containing momentum dependent fermion self energy, and the calculation of determiant and fermion condensate is generalized to the case with arbitrary external gauge fields.
Complex astigmatic elliptical beams possess very high orbital angular momentum. This kind of beams has important applications in many fields, such as atomic physics and biology. An experimental method of optical torsion balance to measure the orbital angular momentum of the beams is presented in this paper. In our experiment, the absorption slice rotates under the irradiation of the beam. The angu...
In this paper we present an improved nuclear density model. We have found the nuclear effect parameters’ formula RAV(x,Q2) and RAS(x,Q2) for the valence quark distribution and sea quark distribution in the nucleus, in which we have used the relation between the nuclear density and the mean binding energy in nucleus. By using the model, we can well explain the experimental data of the of Drell-Yan ...
Using the carbon coated expanded polystyrene (EPS) beads as filling admixture, the electromagnetic (EM) wave absorber more moistureproof and environment adaptive than the conventional absorber used in anechoic chamber was fabricated. The effective permittivity of the mixture with carbon volume content 1% was calculated by the strong fluctuation theory combining with Maxwell-Wagner theory; and the ...
Based on the isospin- and momentum-dependent transport model IBUU04, we investigated the neutron-proton differential flow in the 132Sn+124Sn mid-central collisions at beam energies of 400MeV/A, 600MeV/A and 800MeV/A by adopting two different symmetry energies. It was found that the neutron-proton differential flow as a function of rapidity is very sensitive to the density dependence of symmetry en...
Some experiments at Institute of Applied Electronics of CAEP showed that the interaction between the virtual cathode oscillator and the cavity is a key factor in determining the output microwave power and propagating modes. Particularly, we observed that the E-beam plays an important role in the cavity formation. The experiments have been carried out with 350 kV diode voltage and 23 kA diode curre...
Photon statistical properties of coherent field and thermal field are experimentally studied by means of direct photon counting using only one single-photon-counting module (SPCM) operating in Geiger mode. The second-order degree of coherence as affected by photon counting rate and selected resolution time is investigated systematically. By taking into account all the experimental factors which c...
In this paper, We first fitted the numerical results of the ionization potential calculated by Thomas-Fermi statistical model and gained the analytical function of the potential versus the degree of ionization, then calculated the ionization potential and the average degree of ionization for argon versus temperature and density in local thermal equilibrium (LTE) case. The curve of pressure versus ...
A double band left-handed (LH) microstrip is designed based on defected ground structure (DGS) and Split Ring Resonators (SRRs) with broad bandwidth and low loss while the size of the unit cell is small and the synthesis is simple. Its effective permittivity and permeability are both extracted from the transmission and reflection data of the left-Handed microstrip, then the wave number k is calcul...
In this paper, we propose a novel scheme to produce a longitudinal controllable double-well optical dipole trap for cold atoms (or cold molecules), which is composed of a binary π-phase plate and a lens. The π-phase plate consists of two homocentric rings with equal area and opposite phase (0 and π), and its central region is opaque. When a plane light wave passes through the above optical syst...
We have calculated electron energy loss spectrum for electrons transmitted through a mask in projection electron lithography by Monte Carlo simulation based on the dielectric function model and Mott elastic scattering cross section. A good agreement between simulation and experiment is obtained. The calculation results of the transmission and contrast for the masks in scattering angular limitation...
The products of fast ions H+, H+2 and H+3 with the energy of 0.6 to 1.8MeV passing through carbon films were measured. The yields of neutral atom H and negative ion H- for H+ at energies of 0.6,0.9,1.2,1.6 and 1.8MeV were obtained, respectively. The fitted yield curves as function of velocity of projectile agreed with experimental results very well. The transmission of H+2, H+3 at energies 1.2MeV ...
Based on the equivalence principle and the reciprocity theorem, the problem of electromagnetic scattering from two adjacent objects is considered and a solution that accounts for multiple scattering up to second-order is evaluated. In general, the first-order solution can easily be obtained by calculating the scatted field from isolated targets when illuminated by a plane-wave. However, due to the...
A scheme employing a lens array and the technique of smoothing by spectral dispersion is presented for uniform irradiation on targets in inertial confinement fusion. Quasi-near field spots with a profile of sharp edge and flat top can be obtained with a diffraction-weakened lens array, while the speckles imposed on the spot by beamlets interference can be smoothed by spectral dispersion. Simulatio...
A method to determine the growth polarity of GaN/AlGaN multi-quantum wells (MQWs) has been proposed. Electron holography (EH) study of the potential profiles of the multi-quantum well structure has been used here to determine the direction of build-in electric field that is strictly related to the growth polarity.
The interactions between a two-level atom and a coherent field with a time-varying frequency without rotating-wave approximation have been investigated. The typical cases of the frequency of the field varying with time in the sine and rectangle forms have been considered. It is found that the collapse-revival phenomena and quick oscillations due to virtual photon processes of the atomic populatio...
The light power-current (L-I) characteristics of vertical cavity surface emitting lasers (VCSEL),which have the same fabrication process and structure, but different detunings of Fabry-Perot (FP) resonance from the gain peaks at room temperature, were measured in the temperature range from 261K to 369K. The relationships between the output light power, threshold current, slope efficiency and lasi...
An optimized comprehensively analytical thermal model was developed in accordance with interior heating characteristics of a gain-guided, top-emitting vertical-cavity surface-emitting laser with c.w. operation under room temperatures. Lateral thermal effects in AlInGaAs/AlGaAs vertical-cavity surface-emitting lasers were calculated analytically in detail. The comprehensively analytical solutions e...
We have investigated the periodic poling characteristics of MgO: LiNbO3 and properties of the domain wall velocity. Based on back-switching reaction, domain-inverted velocity can be accurately controled by multi-impulse electric field, which can be used to fabricate MgO: LiNbO3 with submicron uniform periodical structure. At the same time, we studied the cause of formation and the mechanism of sub...
The generation of group delay ripple and reflection sideband is explained by the oscillazation theory. And the effect of non-constant change of averaged index modulation induced by the one-side exposure apodization on the characteristics of chirped gratings is analyzed for the first time. The mechanism of apodization to enhance the performance of chirped fiber Bragg gratings is studied also. Based...
The multi-scattering theory (MST) method is applied to study the band structure of the two-dimensional phononic band-gap material. A comprehensive study is performed for the coupling between various order components of the cylindrical scattered wave. It has been found that there are decoupling effects at the edge of the band gap. Therefore, a self-contained self-consistent multiple scattering mode...
PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES
The configuration and mechanism of a microhollow cathode discharge (MHCD) is introduced in this paper. The focus is a new type of cold atmospheric large-area plasma source, the fused hollow cathode (FHC) plasma source based on radio frequency hollow cathodes. Through its applications and related research, we present the characteristics of the hollow cathode discharge and the factors on which its c...
Non-local transport characteristics of the deep sub-micrometer NMOS device are studied under electro-static discharge (ESD) stress. The result obtained shows that velocity overshoot may increase the drain current and has a great impact on the device characteristics, and that the energy relaxation time is correlated closely with the electric field of some point in the device as well as the velocity...
The interaction between laser and material can induce strong shock wave, so a new subject of science and manufacture technology—photomechanics is being founded on the basis of the mechanical effect of laser induced shock wave which is applied in areas such as laser shock shaping and laser spallation measurement. One of the key problems is to enhance the pressure peak value of shock wave effectivel...
By using a two laser beam method, the spectra of laser-induced air plasmas (LIAP) were studied experimentally. Two laser beams of a laser were used in the experiment. One of the beams was used to create the plasmas, which is called the ionizing-laser-beam (ILB), and the other beam was used to give influence to the plasmas, called action-laser-beam (ALB). This paper reports the experimental results...
The effect of laser incidence angle on the angular distribution of hot electrons generated in the interaction of an ultrashort intense laser pulse with the foil target are investigated. A new emission peaked in the target surface direction is observed for the first time. With the increase of the incidence angle, the ratio of the number of surface electrons to the total electron number increases, w...
Property of rectangular structure surface wave plasma was reported. Large-area uniform and high density plasma was produced by the optimization of slot antenna and the shape of dielectric plates. Plasma density and electron temperature for different operation conditions were measured by a Langmuir probe. Profile of plasma density along the vertical direction was modeled by a diffusive model, and t...
Energy spectrum and angular distribution of fast electrons are measured in the interaction of linearly (P and S) and circularly polarized femtosecond laser pulses with an aluminum target. It is interesting to note that the angular distribution of backward going electrons is unique for S and circular polarization. For S polarization, the angular distribution of fast electrons can be explained by ta...
Experimental study on plasma radiation characteristics of W wire array Z pinch with different initial parameters performed on Qiangguang-Ⅰ pulsed power generator of 1.4—2.1MA current with 80—100ns rise time is reported. The generator configuration and the diagnostic system for the experiments are briefly described. The total X-ray energy and peak power have been measured, and the maximum of X-ray ...
On the basis of one-dimensional fluid model, the characteristics of a homogeneous discharge at atmospheric pressure in nitrogen are numerically investigated. The primary processes of excitation and ionization in N2 are considered. The species included in the model are the electron e,N2 in the ground state,two ions N+2,N+4 and two metastable states N2(a1∑-u),N2(A3∑+u). The simulation results show t...
We present a theoretical and computational model to study the ionization of the electron cyclotron resonance (ECR) microwave discharge using a quasi-three-dimensional electromagnetic particle-in-cell plus Monte Carlo collision method. The interaction between the charged particles and microwave fields are described by particle-in-cell method. The collision processes are treated with Monte Carlo met...
We present a theoretical and computational model to study the ionization of the electron cyclotron resonance (ECR) microwave discharge using a quasi-three-dimensional electromagnetic particle-in-cell plus Monte Carlo collision method. The simulation code is original. The detailed information about the distribution of charged particles and electromagnetic fields are obtained. We can conclude that ...
Framing shadowgraphy of UV laser probing with the 4th harmonic Nd-YAG Laser was developed for the diagnosis of Z-pinch plasmas. This system can effectively shield visible light and has advantages of high temporal resolution, large optical angular aperture and wide measuring range. The designed parameters and experimental results in implosions of tungsten wire array are presented in this paper.
Pinhole imaging of the neutron production in laser-driven inertial confinement fusion experiments can provide important information about performances of various capsules designs. In order to get good results in experiments, it is needed to judge the performance of various pinhole designs qualitatively or quantitatively before experiment. Calculation of imaging can be simply separated into pinhole...
The problem that Cherenkov radiation may exist in the ion-channel when a relativistic electron beam (REB) is injected into plasma has been demonstrated and studied. The effect of the beam-wave interaction in ion background is analyzed by use of the linear perturbation theory. The dispersion equation and the simultaneous radiation condition of the system are derived. It is clearly shown that the el...
Low-temperature polycrystalline Si films were fabricated by radio frequency plasma-enhanced chemical vapor deposition using SiH4, Ar and H2 as source gas. It was found that the content of H2 in the mixture plays an important role for crystallization of Si films. High-quality low-temperature polycrystalline Si films were obtained under the optimal amount of H2 in the source gas.
The runaway breakdown model induced by fast electrons is promising in explaining the nanosecond-pulse breakdown. In this paper, runaway process and collision ionization of fast electrons are discussed. Based on the relations between the electron energy and effective retarding force, the evolution of injected electron energy as a function of distance away from the avalanche head was simulated. The ...
The process of coplanar dielectric barrier discharge (DBD) has been investigated experimentally and theoretically by using a segmented-electrode system. The local discharge current, light emission intensity and the developing velocity of plasma on the cathode were obtained. The results of the experiment and the two-dimension fluid modeling are compared. It was shown that there exists a non-uniform...
CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES
Measurements were carried out under hydrostatic pressure up to 0.5GPa at room temperature, by using an ultrasonic pulse-echo method to measure the transit time of longitudinal and transverse elastic waves (10MHz) in a Nd60Al10Fe20Co10 bulk metallic glass. Based on the experimental data, the sound velocity, density, elastic moduli and Debye temperature were derived as functions of pressure, and the...
Based on the theory of dislocations, we have constructed the four models of the 〈100〉{010}, 〈100〉{011}, 1/2〈111〉{011} and 1/2〈111〉{112} edge dislocations in bcc Fe using the molecular dynamics method, and the formation energy, core energy and core radius of the dislocations have been calculated respectively. The calculated results indicated that the formation energies of 〈100〉{010} and 〈100〉{011} ...
A V∶YAG single crystal was grown by the temperature gradient technique (TGT) with graphite heating elements, which exhibited two kinds of colorations of light-green and yellow-brown in different parts. Differences in absorption spectra of three samples with different colors suggest that the reduction effect of carbon diffused from the heating element should enhance the concentration of tetrahedral...
The water saturated Arabidopsis seeds were irradiated with protons in air. The ion energy is from 1.1MeV to 6.5MeV. According to TRIM simulation, the damaged region of the seed induced by the incident ions is near the surface region of the embryo, half of the embryo and the whole embryo, respectively. The protons with high energy can damage the shoot apical meristem(SAM) in the embryo while the p...
The investigation of GdBaCo2O5+δ system using low frequency internal friction method indicates that there exists a relaxation internal friction peak originated from the jump of excess oxygen atoms. The excess oxygen content δ affects greatly the height, shape and position of the peaks, which reflects the state of the excess oxygen varying with the value of δ. When the excess oxygen content is very...
We have performed total energy calculations on the structural and adsorption properties of Cu(100) c(2×2)-N surface by using DFT PAW method. It is concluded that nitrogen adsorbed on a four-fold coordinated site with a perpendicular distance of 0.2? from the surface Cu layer. The shortest Cu-N bond length is calculated to be 1.83?. Geometry optimization calculation excludes the possibilities of ad...
Stresses and its variation of coating and matrix are measured by XRD (X-ray diffraction). A test system that measures coating stress on the bonding interface is established, and the measurement of interface bonding status is researched. By using interfacial stress variation before and after coating debonding from matrix, combined with the physical parameters of coating material and temperatures fi...
Two series of ZrN/AlON nanomultilayers were synthesized by reactively sputtering zirconium and aluminum oxide targets in the gaseous mixture of argon and nitrogen. The thickness of ZrN layers was fixed in one of the series and the thickness of AlON layers in the other. The composition, microstructure and mechanical properties of films were characterized by X-ray energy dispersive spectroscopy, X-r...
CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
Intensity parametrization of the electric dipole transitions within 4f2 configuration of Pr3+ in SrAl12O19 are reported, in which the mixing of the 4f2 transitional states with the explicit 4f5d states is taken into account. A new set of phenomenological intensity parameters, Tkq, are put forward, which are obtained from a best fit of the calculated and measured relative intensities of transitions...
We present a first-principles study of the atomic hydrogen adsorption onto the Be(1010) thin film.There are two types of Be(1010)surfaces according to the interlayer spacing between the surface and its nearest-neighbor layer. We show that the H adsorption features on these two kinds of surfaces are remarkably different. The work function, averaged electrostatic potential, and the local charge dens...
The potential energy curves of B2 and B19′ phase for NiTi alloys were investigated with the norm-conserving and plane-wave ultrasoft pseudopotential in the local density approximation. Our results reveals that the B19′ phase is more stable than the B2 phase at absolute zero temperature due to lower potential energy of the former. In the B2 phase, the alloying atoms Au and Fe (at Ni site) occupy th...
Based on the density functional theory (DFT), using full-potential linearized augmented plane wave and improved local orbital (APW+lo) method, the structure and magnetism of the rare-earth permanent magnetic materials YFe11Ti are analyzed and calculated. The formation energy of YFe12,Y2Fe17 and YFe11Ti are calculated, The stabilization effect and the possible positions of the substituted atom Ti a...
The adsorption properties of metal atoms on the hydroxyl SiO2 surface have been studied by using first-principles calculation. It is found that In and Ga atoms are weekly bound to the surface, while Fe, Co and Ni atoms are bound to both Si and O atoms with strong chemical bonds. Potential energy surface and diffusion barrier calculations show that In (Ga) can easily diffuse on the surface because ...
The complete diagonalized Hamiitonian matrixes of 3d2/3d8 ion configuration with trigonal symmetry have been established by irreducible representation method. The spectral hyper-fine structure and the constants of crystal structure and zero-field splitting parameters of CsNiCl3 crystal, as well as the Jahn-Teller effect and the influence of the spin singlet on the ground levels of Ni2+ ion have be...
The completely diagonalized Hamiltonian matrixes of order 120 of 3d3/3d7 ions configuration in the trigonal symmetry have been established by irreducible representation method and group theory, taking into account spin-orbit interaction and spin-spin interaction. The ground-state energy levels, the zero-splitting parameter and Jahn-Teller effect of ruby crystal were calculated with the matrixes. T...
In order to further study the influence of the arrangement and matrix number of the conductive nanowires array on the field emission from the array, the more practical conductive hexagonal and square nanowire arrays were simulated with the mirror image floating sphere model in this paper. From the calculation results, the field enhancement factor of conductive nanowire array was expressed as the ...
Electric pulse of photoconductive switches is determined by transmission character of photo-generated carriers. In the course of transmission, inductive current on the electrodes is formed by photo-generated carriers with high drift speed. Conductive current is formed only after the carriers are absorbed by electrodes. Inductive current and conductive current are calculated by numerical method in ...
First-principle calculations in the frame of density-functional theory (DFT) in the general gradient approximation (GGA) are performed by using the augmented plane wave plus local orbital (APW+lo) method for pure GaAs(110) surface and the adsorptions of Xe atoms on it. A supercell consisting of five atomic layers is constructed to simulate the geometical configuration of clean GaAs(110) surface an...
Doubly stacked layers of amorphous silicon (a-Si) between amorphous silicon nitride (a-SiNx) layers have been fabricated by plasma enhanced chemical vapor deposition (PECVD)technique. Si nanocrystal (nc-Si) layers were formed by thermal crystallization of a-Si layers after a furnace annealing at 1100℃ for 30 min in N2 ambient. The phenomena of charge trapping and storage in nc-Si layers were obser...
After pre-metallization processing of AlGaN/GaN heterostructure with O2 plasma and HF solution, the Ni/Au Schottky contact characteristics were improved obviously and reverse leakage current reduced by three orders. In addition, annealing experiments were carried out at 200—600℃ for 5min in N2 atmosphere on many batches of Schottky diodes, the reverse leakage current decreased further with anneali...
In this work, a method for calculating mobility of nano-scaled MOSFETs from the Boltzmann transport equation(BTE) is presented. Some approximations are assumed for the BTE in nano-scaled MOSFETs, and an improved distribution function of the carriers is obtained which is used to model the mobility of carriers. An analytical expression of carrier mobility is deduced considering the statistical distr...
Nonv-electrical plating was employed to form nickel inducing source on the surface of α-Si thin film deposited by VHF-PECVD. It was observed that the nickel inducing source formed by this method appeared as “dots” uniformly distributed on the surface of a-Si thin film after annealed for several hours at 550℃. The quantity of “dot” on the a-Si was determined by Ni concentration in the solution, the...
Porous silicon (PS) with different porosity was obtained by anode electrochemical etching of boron-doped Si (100); the as-etched samples were then covered with Fe films by magnetron sputter technique. Analysis of surface profile and structural investigation were done by scanning tunneling microscopy and X-ray diffraction. Magneto-optical Kerr effect was employed to measure the hysteresis loops of...
Magnetic properties and giant magneto-impedance (GMI) effects of FeCuCrVSiB single layered and multilayered films with Ag as the central layer and SiO2 as the isolating layers, which were prepared by radio frequency sputtering without field and with a magnetic field about 72kA/m along the films length, are investigated. The hysteresis loops of single layered films show that the samples deposited w...
The investigations on the structure, magnetic and transport properties were carried out for the double perovskite Sr2Fe1-xCoxMoO6 samples prepared by the solid state reaction method. It is found that the relationship between resistivity and temperature changes from a typical half-metal behavior to a semiconductor behavior, with the increasing substitution concentration x value of Co for Fe. The re...
The characteristics of the TDDB (Time-dependent dielectric breakdown) under the CVS (constant voltage stress) and the gate current model of devices under V-ramp stress were studied in the 1.4nm-thick n-MOSFET. The degradation and failure mechanisms were analyzed. The gate current is produced by the tunneling, the electron surmounting and percolation. During the stress process, the created traps in...
Lanthanum doped lead titanate (PLT) ferroelectric thin films were grown on Pt/Ti/SiO2/Si(100) substrates using RF magnetron sputtering. X-ray Diffraction (XRD) was applied to study crystalline properties of PLT films, and XRD patterns of PLT thin films show that there appeared (111) preferred-oriented tetragonal perovskite phase. The ferroelectric domain patterns and the corresponding topography o...
Hot band of a continuous cast AA 2037 Al alloy was annealed at different temperatures ranging from room temperature to 500℃ for 3h. Vacancy-solute interaction and precipitates in the hot band samples during annealing were investigated by positron annihilation techniques, coincidence Doppler broadening (CDB) of positron annihilation radiation and positron lifetime spectroscopy, and other methods. T...
Aligned and unaligned In2O3 nanowires were prepared based on our homemade equipment and the field-emission properties of In2O3 nanowires(NWs) were investigated.It was found that aligned In2O3 NWs have better performance than unaligned ones. The aligned NWs have lower turn-on and threshold electric fields. This might be attributed to the weaker field-screening effect between the neighboring aligned...
The surface-conduction electron-emitter display(SED) based on tunneling effect is a newly developed flat panel display. It has obvious technical advantages and excellent characteristics and is praised as one of the most advanced displays. Based on the theory of electromagnetism, an equivalent physical model of a single pixel of SED is established. In particular, it shows the exterior charge densit...
INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY
Hydrogenated microcrystalline silicon (μc-Si∶H) films with high crystalline volume fraction were deposited using a novel hot wire assisted microwave electron cyclotron resonance-chemical vapor deposition (HW-MWECR-CVD) system. The Raman scattering spectrum and X-ray diffraction measurements were carried out to characterize the microstructure of the films. It was shown that, in a wide range of sila...
In oxyfluoride glass-ceramics, the fluoride nanocrystals doped with rare earth ions were dispersed in an oxide network. The emission of Eu3+ has high sensitivity to different crystal field and is suitable for microstructure research in neoceramic glass. Different oxyfluoride glass ceramics doped with Eu3+ were prepared. The variation of the emission spectra of Eu3+ in different glass ceramics conf...
Isothermal oxidation behaviors of pure and yttrium-implanted nickel were studied at 900℃ in air. SEM and TEM were used to examine the oxide scales formed on nickel substrate. Acoustic emission (AE) technique was used to monitor the cracking and spalling of oxide film in isothermal oxidizing stage and subsequent air-cooling stage. AE signals were analyzed in time and number domain according to the ...
The synchrotron radiation (SR) stimulated etching of SiO2 thin film surface was investigated with a contact cobalt mask, and the etched pattern of SiO2 thin films on silicon was made. The SiO2 thin film was grown on silicon surface by thermal oxidation. The contact cobalt mask was fabricated on SiO2 thin film by combining the techniques of photolithography and RF-magnetron sputtering. In the exper...
Colloidal crystals are fabricated through a self-assembly process of monodispersed polystyrene particles. Evolution of colloidal crystal structures is analyzed by Kossel diffraction technique and UV-Vis spectrophotometer. According to the changes in the Kossel patterns we find the crystal structures change with passage of time and experience successively the following stages: liquid state-random l...
A series of ZrO2 and polyvinylpyrrolidone (PVP) doped-ZrO2 sols have been synthesized by the controlled hydrolysis and condensation of zirconium n-propoxide, with diethanolamine (DEA) as the chelating agent. PVP-ZrO2 hybrid monolayers and highly reflective (HR) multilayer coatings were then prepared by spin-coating the stable sols on K9 glass substrates. The fabrication of the HR coatings involves...
The daily precipitation observational data of 740 stations from 1960a to 2000a Which provided by National Climate Center of Chinese Meteorologial Administration, are divided in sections and statistically analyzed. A common feature is revealed——the power-law distribution, and different precipitation corresponds to different power-law exponent; this to a certain extent reflects that different precip...
Considering a non-feedback mechanism of action,the present paper shows that the steady forcing induces amplitude death in chaotic system by investigating the bifurcation figures and the spectrum of Lyapunov exponents of the R?ssler oscillator. The manner, which is very similar to that in coupled limit cycles or coupled R?ssler system, is from periodic to an equilibrium point of the forced system. ...