Properties and Structure of a Plasma Non-Neutral Shock

The shock is described by the Navier-Stokes equations of the electron and ion fluids, and coupled with Poisson‘s equation for the self-induced electric field. Profiles of the flow and electric variables in the weak or moderate shock front with or without current for different Debye lengths are presented. Comparison of profiles of flow and electric variables in the front for different heat flow modes is given.     

Effect of the Sintering Temperature on the Formation of Ferroelectric Properties of a Lead Zirconate–Titanate Ceramic

Effect of the sintering temperature on the formation of the microstructure, the domain structure, and the ferroelectric properties of a lead zirconate–titanate Pb(Ti _x Zr_{1 – x})O₃ piezoelectric ceramics has been studied. It is shown that the ferroelectric phase forms at a sintering temperature of 860°C. At higher sintering temperatures, the main effect on the properties is due to a unit cell deformation and free charge carriers.     

Optical Limiting and ExcitedState Nonlinear Optical Properties in Lead Phthalocyanine

1.IntroductionLeadphthalocyaninehasreceivedconsiderableattentionasitexhibitsstrongreversesaturableabsorption(RSA)behaviorLI].Thiskindoforganometalliccompoundcanbeusedasopticallimitingdevicetoprotecteyesandsensorsfromlaserhazard.Thenanosecondopticallimitingpropertyofleadphthalocyaninehasbeeninvestigatedyet[2].Inthispaper,thepicosecondopticallimitingbehaviorofleadphthalocyanine(Pbpc(CP)4)ispresentedandtheresultiscomparedwithC6o,areversesaturableabsorptionmaterialwhichhasbeenwidelystudied.The…     

Behaviuour of Polariton in a Simple Model

Behaviour of a simple model polariton system is restudied.The distribution of phonons in polartion never is sub-Poisson given by computation of the thermal counterpart of the Q parameter and the matrix m^(3).The polariton complex as a whole shows non-classical behaviour below a threshold temperature,which depends on the photon-phonon coupling strength,when the distribution of phonons is always classical at any temperature.     

Absorption and Emission Properties of a New Two-photon Absorption Dye

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Properties of Structure and Dynamics of a Two-Dimensional Dissipative Yukawa Dusty Plasma

In this paper, the structural and single-particle motive properties of a two-dimensional dusty plasmas are investigated numerically by molecular dynamics simulation within the framework of a dissipative Yukawa model. The pair correlation function, the mean square displacement, the static structure factor, and the bond angle correlation function characterizing the structural properties, and the velocity autocorrelation function with Fourier spectrum function characterizing the single-particle motion have been calculated for different values of coupling constant r and viscous damping constant vf. The results show that the system will coagulate quickly with increasing viscous damping constant and coupling constant, and the critical value of friction parameter decreases with increasing the coupling constant in the system.     

Temperature Properties of Dielectric Permittivity and Optical Properties of a Multilayer Structure of Variozone Barium–Strontium Titanate

Physics of the Solid State - Optical properties and the temperature dependence of the permittivity of a multilayer structure of a variozone ferroelectric barium-strontium titanate deposited on a...     

Size Dependences of the Magnetic Properties of Superconducting Lead–Porous Glass Nanostructures

Superconducting structures Pb–PG formed by filling a porous glass matrix with the lead from melt under pressure have been investigated. Samples with characteristic pore structure diameters of d ≈ 7, 3, and 2 nm have been studied. It has been found that the critical temperature of the superconducting transition in the samples under study is similar to the corresponding value T_c ≈ 7.2 K for bulk lead. At the same time, it has been observed that the critical magnetic field of the nanocomposites, which attains H_c(T = 0 K) ≈ 165 kOe for Pb–PG (3 nm), exceeds several times the value H_c(0) = 803 Oe for bulk lead. The low-temperature magnetic- field dependences of magnetic moment M(H) contain quasi-periodic flux jumps, which vanish with a decrease in the lead nanostructure diameter. A qualitative model of the observed effects is considered.     

Comparison of Properties of Pt/PZT/Pt and Ru/PZT/Pt Ferroelectric Capacitors

Pb（Zr0.4Ti0.6）O3 film prepared by sol-gel spin coating on a Pt/Ti/SiO2/Si substrate is applied to ferroelectric capacitors with Pt or Ru as the top electrode. For the Pt/PZT/Pt and Ru/PZT/Pt ferroelectric capacitors, although with the same ferroelectric film, different top electrode materials incur different properties of PZT capacitors, such as fatigue, leakage, remanent and saturated polarization, except the similar crystal orientations of the PZT film. After 10^10 switch cycles, the remanent polarizations of the Ru/PZT/Pt and Pt/PZT/Pt capacitors decrease to 70% and 84%, respectively. The leakage current density of the latter increases obviously at positive bias after 108 switch cycles, compared with the former. Different materials for the top electrode bring different conditions at the PZT/top electrode interface. The influence of oxygen-vacancy concentration at the PZT/electrode interface and the influence of oxides of the electrode material at the PZT/electrode interface to charge injection can explain the difference of properties of the PZT capacitors with Pt or Ru as the top electrodes.     

Squeezing and Higher-order Squeezing Properties of Eigenstates of the Operator akqs

The squeezing and higher-order squeezing properties of k orthonormalized eigenstates of the higher powers akqs(k≥3) of the annihilation operator of two-parameter deformed harmonic oscillator are investigated. It is found that the Nth-power squeezing [N=(m+1/2)k, m=0,1,2,…] can exist in the all of them when k is even.     

Electric and Magnetic Properties of a New Ferrite—Ceramic Composite Material

We have investigated a new ferrite-ceramic composite material with inductive and capacitive properties fabricated by a solid-state reaction method.We analyse the effects of the composite mechanism and microstructure on the magnetic and electric properties.The results show that the new materials can be used not only as inductor materials,but also as capacitor materials in the wide frequency range of 1kHz-1.8GHz.The real part of permeability of the composite material is between 10 and 5.6,the imaginary part of permeability is between 1.2 and 0.5,and the dielectric constant is about ten times larger than that of ordinary ferrite materials.It is suggested that the new composite materials will be widely used in anti-electromagnetic interference fields and radio frequency communication fields.     

Preparation and Properties of Polyamide 66/Organo‐Vermiculite Nanocomposites

Polyamide 66/organo‐vermiculite (OVMT) nanocomposites with different clay loadings were prepared via melt mixing using a twin‐screw extruder. The vermiculite was premodified with hexadecyl trimethylammonium bromide by ball milling. The resultant polyamide 66/OVMT nanocomposites possessed an exfoliated structure as confirmed by both wide angle X‐ray diffraction (WAXD) and transmission electron microscopy (TEM). Mechanical property tests showed that the tensile strength, flexural modulus, and flexural strength of these nanocomposites increased dramatically with the OVMT loading, and the Charpy impact strength and fracture toughness decreased. In addition, the heat distortion temperature of the nanocomposites showed an obvious increase compared with pure polyamide 66. Finally, differential scanning calorimetry (DSC) results showed that the crystal structure and crystallization behaviors of the nanocomposites are different from those of polyamide 66.     

AssociateJ/ψ+γ production: a clean probe of gluon densities

Production of strange and charm particles by hadron-proton collisions is analyzed in terms of a fire-ball (FB) model assuming the multiplicity of secondaries of a given massm, to be proportional to the FB mass: n(m)M ^*, the FB kinematics being determined by the Feynman-Yang scaling, as in the case of production. It is found that (m)1/m ² and that, using this property together with the scaling, no-free-parameter fits to currently available data of strange and charm particles frompp and p collisions are satisfactory, as well as for the photoproduction of charm mesonD and charm hyperon _c .     

Utilization of Electromagnetic Detector for Selection and Detection of High-Frequency Relic Gravitational Waves

It is shown that the coupling system between fractal membranes and a Gaussian beam passing through a static magnetic field has strong selection capability for the stochastic relic gravitational wave （GW） background. The relic GW components propagating along the positive direction of the symmetrical axis of the Gaussian beam might generate an optimal electromagnetic perturbation, while the perturbation produced by the relic GW components propagating along the negative and perpendicular directions to the symmetrical axis will be much less than the former, and the influence of the random fluctuation of the relic GWs to such effect can be neglected. The high-frequency relic GWs satisfying the parameters requirement （h - 10^-31 or larger）, frequency resonance and “direction coupling”, in principle, would be selectable and measurable in seconds.     

The Photophysics of β-Tyrosine and Its Simple Derivatives

Synthesis and photophysical studies of (O-methyl)--tyrosine (-tyrosine; an analogue of tyrosine, in which the amino group is moved from the - to the -carbon, closer to the phenol ring) and its derivatives with a blocked amino and/or carboxyl group were performed to explain the nature of the fluorescence of tyrosine derived analogues. All -tyrosine derivatives, except Ac-Tyr(Me), displayed the monoexponential fluorescence decay. The biexponential fluorescence decay observed for Ac-Tyr(Me) is assumed to be the result of the presence of two low-energy conformations (extended and with an intramolecular hydrogen bond). Higher quenching of the fluorescence of -tyrosine derivatives by the N-acetyl group than by the N-methylamide group moved farther was found, contrary to the data found for the respective derivatives of natural tyrosine. The obtained photophysical data are discussed with theoretical calculations (AMBER, AM1) on the basis of the rotamer model.     

Synthesis and Optical Properties of ZnO Nanostructures

ZnO nanostructures with different morphologies were fabricated by changing the partial oxygen pressure. The structures, morphologies and optical properties of ZnO nanostructures were investigated by x-ray diffraction, field emission scanning electron microscopy and photoluminescence (PL) spectra at room temperature. All the samples show preferred orientation along the c-axis. The oxygen partial pressure and the annealing atmosphere have important effect on the PL property of ZnO nanostructures. The high oxygen partial pressure during growth of samples and high-temperature annealing of the ZnO samples in oxygen can increase oxygen vacancies and can especially increase antisite oxygen (OZn) defects, which degraded the near band-edge emission. However, the annealing in 1-12 can significantly modify the NBE emission.     

Fabrication and Photoluminescence Properties of ZnO Nanorods

ZnO nanorods are successfully synthesized by annealing the precursors in argon with the chemical precipitation method. The structural and optical properties of ZnO nanorods are investigated. As annealing temperature increases, the intensity of the green emission increases while the intensity of the yellow emission decreases. The result suggests that the green emission depends strongly on the annealing temperature.     

Preparation and Luminescent Properties of ZnO Microrods and Microtubes

Hexagonal ZnO microrods and sub-microrods have been prepared through thermal decomposition of an equimolar (0.1 M) aqueous solution of Zn(NO3)2.4H20 and (CH2)6N4 a~t 90~C for different times (10-46h). The microrods were transformed into hollow hexagonal ZnO microtubes when the growth time reached 46 h. The Raman spectra and the photoluminescent (PL) spectra were measured. The PL spectra of microrods consist of two strong narrow near-UV bands at 380 nm and 400 nm assigned to free exciton emission and exciton-exciton collision, respectively.The PL spectrum of ZnO microtubes show only one peak in the near-UV region with peak located at 380nm with FWHM of about 20nm assigned to free exciton emission. When the growth time increased, the peak intensity of near-UV band decreased.