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1.
We consider the earthquake model on a random graph. A detailed analysis of the probability distribution of the size of the avalanches will be given. The model with different inhomogeneities is studied in order to compare the critical behavior of different systems. The results indicate that with the increase of the inhomogeneities, the avalanche exponents reduce, i.e., the different numbers of defects cause different critical behaviors of the system. This is virtually ascribed to the dynamical perturbation.  相似文献   

2.
Based on the analysis for the main elements of the total modulation transfer function (MTF) of imager on geostationary platform, the precise evaluation for its low spatial frequency spectrum has been achieved. Meanwhile, it is pointed out that the main cause of imagery spatial resolution lower than the designed value is the "slight defocus" of imager focal plane array (FPA). The validation method for visible imagery spatial resolution is proposed based on the analysis of defocused optical system model and edge-spread-function (ESF), the relative error is less than 7% after alleviating stray light effects. This method has been applied in the in-orbit ground testing of FY-2C geostationary meteorological satellite successfully.  相似文献   

3.
A computer simulation was performed to explore the features and effects of sedimentation on rapid coagulation.To estimate the accumulated influence of gravity on coagulation for dispersions, a sedimentation influence ratio is defined. Some factors possibly related to the influence of sedimentation were considered in the simulation and analysed by comparing the size distribution of aggregates, the change in collision number, and coagulation rates at different gravity levels (0g, 1g and more with g being the gravitational constant).  相似文献   

4.
The effects of ultrasound on the hatching of the goldfish(Carassiusauratus auratus)and loach(Paramisgurnus dabryanus(sauvage))cytulas werestudied.The ultrasound with certain frequencies can accelerate the developmentof cytulas,induce the embryos to break membrane earlier,increase the survivalrate of larvas,and increase 50% hatching rate of loach cytulas at lower temper-ature.  相似文献   

5.
The impurities in two kinds of HfO_2 materials and in their corresponding single layer thin films were determined through glow discharge mass spectrum technology and secondary ion mass spectrometry(SIMS) equipment respectively.It was found that ZrO_2 was the main impurity in the two kinds of HfO_2 either in the original HfO_2 materials or in the electron beam deposited films.In addition,the difference of Zr content in the two kinds of HfO_2 single layer films was much larger than that of the other impurities such as Ti and Fe,which showed that it was just ZrO_2 that made the difference between the optical performance of the film products including the two kinds of HfO_2.With these two kinds of HfO_2 and the same kind of SiO_2,we deposited HfO_2/SiO_2 multilayer reflective coatings at the wavelength of 266 nm.Experimental results showed that the reflectances of these two mirrors were about 99.85% and 99.15% respectively, which agreed well with the designed results what were based on the optical constants obtained from the corresponding single layer thin films.  相似文献   

6.
Y. Song  J.H. Dai  R. Yang 《Surface science》2012,606(9-10):852-857
We studied the adsorption behavior of oxygen on low index surfaces of γ-TiAl via first principles to investigate the mechanism that drives the adsorption behavior. The (100) surface is the most stable surface energetically followed by the (111), (110) and (001) surfaces. A study of the adsorption of a single oxygen atom on surfaces of TiAl showed that the O atom prefers the Ti-rich environment that has a high potential of generating TiO2. Competition between O-Al bonding and O-Ti bonding was observed in the O adsorbed surface regions. However, the O-Ti interaction dominates the adsorption behavior in all considered systems except when O is adsorbed on an Al-terminated (001) surface as the O–Al bond is stronger than O–Ti bond. A linear relationship between adsorption energy and integration of orbital overlaps between the O atom and the metals is obtained, which indicates that the electronic structure controls the adsorption behavior of an O atom on a γ-TiAl surface — an opportunity to improve the oxidation resistance of γ-TiAl based alloys.  相似文献   

7.
孙成一  章德海 《中国物理快报》2006,23(12):3388-3390
By conjecturing the physics at the Planck scale, we modify the definition of the Hawking temperature and modify the Friedmann equation. It is found that we can avoid the singularity of the big crunch and obtain a bouncing cosmological model.  相似文献   

8.
We study the influence of viscosity on DNA dynamics. By employing the nonlinear Peyrard-Bishop-Dauxois (PBD) model, it is shown that the DNA dynamics can be explained by a solution of a complex nonlinear Schrǒdinger equation (CNLSE). This is the nonlinear Schrǒdinger equation (NLSE) with a nonlinear parameter being a complex number. We compare real and imaginary parts of this nonlinear parameter and show that the latter one should not be negligible, which means that the CNLSE should be solved numerically,  相似文献   

9.
We discuss the effect of nonlinearity on the scattering dynamics of solitary waves. The pure nth power model with the interaction potential V (Х) = Х^n/n is present, which is a paradigm model in the study of solitary waves. The dependence of the scattering property on nonlinearity is closely related to the topological structures of the solitary waves. Moreover, for one of the four collision types, the rates of energy loss increase with the strength of nonlinearity and would reach 1 at n ≥ 10, which means that the two solitary waves would become of fragments completely after the collision.  相似文献   

10.
Recent astronomical observations manifest that about two-thirds of the whole energy in the Universe is contributed by a small positive cosmological constant A (> 0). Then, an asymptotically de Sitter spacetime is premised naturally. However, physics in the de Sitter spacetime is very different from that in the Minkowski spacetime. As the first step, a covariant formalism of the kinematics in the de Sitter spacetime is presented here. By solving exactly the equations of motion for a field, we obtain the dispersion relation of a free particle. It is noticed that the dispersion relation is dependent on the degree of freedom of angular momentum of the particle. We show the threshold anomaly of the ultra high energy cosmic ray disappears naturally in the framework of the de Sitter kinematics.  相似文献   

11.
InfluenceofBuffer-LayerThicknessonPerformanceofWaveguideModulators¥XAINGYunnan;WANGKuiru;YUGuoxian;XUDaxiong(BeijingUnversity...  相似文献   

12.
A coarse-grained molecular dynamics simulation model was developed in this study to investigate the friction process occurring between Fe and polytetrafluoroethylene(PTFE).We investigated the effect of an external load on the friction coefficient of Fe–PTFE using the molecular dynamics simulations and experimental methods.The simulation results show that the friction coefficient decreases with the external load increasing,which is in a good agreement with the experimental results.The high external load could result in a larger contact area between the Fe and PTFE layers,severer springback as a consequence of the deformed PTFE molecules,and faster motion of the PTFE molecules,thereby affecting the friction force and normal force during friction and consequently varying the friction coefficient.  相似文献   

13.
1 INTRODUCTIONItwasoftenencounteredthationizationofambient gasshouldoccurredwhena plasmawasproducedwithlaserablatingatarget .Manya  相似文献   

14.
In a recent note Ellis criticizes varying speed of light theories on the grounds of a number of foundational issues. His reflections provide us with an opportunity to clarify some fundamental matters pertaining to these theories.  相似文献   

15.
Oxide films obtained during anodization of Ti?40% Al sintered powder samples in fluorine-containing electrolytes are investigated. With scanning electron microscopy and X-ray phase analysis, it is demonstrated that an X-ray amorphous nanoporous anodic oxide film is formed on the surface of the powder microparticles under optimal anodization conditions. After annealing at T = 1093 K in air and vacuum (10?2 Pa), the oxide films are revealed to crystallize with its regular porous structure retained. The composition of the polycrystalline anodic-oxide films annealed in air is a mixture involving TiO2 (anatase and rutile) and α- and γ-Al2O3 phases and Ti2O3 and Al2TiO5 traces. The vacuum annealing process makes it possible to identify TiO2, in which anatase is the main phase, α- and γ-Al2O3, and Ti2O3 and TiO traces. However, rutile is not revealed. The presented results indicate that the application of the anodic nanostructuring of Ti?40% Al powders is promising for the obtainment of new photocatalytic active nanomaterials.  相似文献   

16.
opening Address(20‘)Hesheng Chen(IHEp) Session 1 hadron sPeetroseoPy and new resonanees eh缸red by Pasha Pakhlov Reeent results on light hadron speetroseo可from BESll(20‘)xia叮an Shen(IHEp) Study of eharmonium(一llke)states via ISR at Belle(20‘)ehangzh  相似文献   

17.
The formulas of the quantum electrodynamics have been applied to calculate the spontaneous emission rate of excited atom in dielectric microcavity.The results exhibit damping oscillating patterns which depend sensitively on the scaling parameter and geometrical structure.Compared with the case that the emitting atom is immersed in dielectric,the spontaneous emission rate is depressed obviously and the center or the mean value of the oscillations is intimately related to the real refractive index of the local position where the atom is.In order to explain this phenomenon,we utilize the closed-orbit theory to deal with the classical trajectories of the emitted photon,and extract the corresponding frequencies of the oscillations by Fourier transform.It is found that the oscillations can be represented in terms of the closed-orbits of the photon motion constrained in dielectric microcavity,thus providing another perspective on the spontaneous emission of atom sandwiched by dielectric slabs.  相似文献   

18.
姜泽军  张力 《中国物理快报》2005,22(5):1289-1292
We study the effect of γ-ray beaming on γ-ray emission of the pulsars in a self-sustained outer gap model. In this model, averaged γ-rav flux is a function of period, magnetic field, magnetic inclination angle and solid angle of γ-ray beaming for a γ-ray pulsar. We generate a sample of γ-ray pulsars with their ages less than 10^6 ears by using the Monte Carlo method, and then study the γ-ray beaming effect. The comparison of distributions of periods, magnetic fields, distances, γ-ray energy fluxes and period derivatives of the simulated γ-ray pulsars with those of observed γ-ray pulsars by the detector EGRET shows that γ-ray beaming has an important role on the detection of γ-ray pulsars. Furthermore, possible γ-ray pulsars observed by the detector GLAST are predicted.  相似文献   

19.
盛新志  娄淑琴 《中国物理快报》2005,22(10):2588-2591
Deformation of some air holes often occurs during the fabrication process of photonic crystal fibres (PCFs). Effects of the location and size of deformation holes on the properties of actual triangular lattice PCFs are investigated in detail. Numerical results demonstrate that the properties of PCFs, especially birefringence, are sensitive to the location and size of deformation holes. These would be very helpful to improve the fabrication technique of the PCF and also offers an efficient way to design high birefringence PCF.  相似文献   

20.
The discharge current and the inception voltage in a surface discharge device have been measured to investigate the influence of wall charges on the discharge characteristics in argon. The results show that the inception voltage decreases as the amplitude of the applied voltage Up increases. However, the sum of the inception voltage and the applied voltage almost keeps constant when Up is changed, due to the fact that the wall charges are generated in the discharge process. This phenomenon suggests that net electric field between the electrodes almost keeps constant when the amplitude of the applied voltage is changed. The electron temperature calculated by the intensity ratio of emitted spectral lines has been estimated to be less than 0.3eV and almost keeps constant under different amplitudes of the applied voltage. The result is consistent with nearly constant net field. The duty ratio of the discharge current increases as the amplitude of the applied voltage increases.  相似文献   

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