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2.
We study the statistical properties of volatility of price fluctuation for the Hang-Seng index in the Hong Kong stock market, they are measured by locally averaging over a time window T, the absolute value of price change over a short time interval Δt. The data include minute-by-minute records of the Hang-Seng index from 3 January 1994 to 28 May 1997. We find that the cumulative distribution of the volatility is consistent with the asymptotic power-law behaviour, characterized by the power exponent μ= 2.12 ± 0.04, different from that found in the previous studies as μ≈3. The volatility distribution remains the same asymptotic power-law behaviour for the time scales from T = 10 rain to T - 80 rain. Furthermore, we investigate the volatility correlations by using the power spectrum analysis and detrended fluctuation analysis. Both the methods show a long-range power-law decay with the exponent α=0.636±0.002.  相似文献   

3.
《Physics letters. A》2014,378(30-31):2280-2284
The local magnetism induced by vacancies in the presence of the spin–orbit interaction is investigated based on the half-filled Kane–Mele–Hubbard model on the honeycomb lattice. Using a self-consistent mean-field theory, we find that the spin–orbit coupling will enhance the localization of the spin moments near a single vacancy. We further study the magnetic structures along the zigzag edges formed by a chain of vacancies. We find that the spin–orbit coupling tends to suppress the counter-polarized ferrimagnetic order on the upper and lower edges, because of the open of the spin–orbit gap. As a result, in the case of the balance number of sublattices, it will suppress completely this kind of ferrimagnetic order. But, for the imbalance case, a ferrimagnetic order along both edges exists because additional zero modes will not be affected by the spin–orbit coupling.  相似文献   

4.
G. G. Bunatian 《JETP Letters》1999,69(10):728-733
In experiments on the β decay of polarized neutrons where only the electron and proton momentum distributions are observed and the γ radiation is not registered, the asymmetry factor B of the antineutrino angular distribution cannot be obtained rigorously — the value of B is only estimated on the average by taking into consideration the expectation (mean) value 〈B〉 and the rms deviation ΔB. The resulting unavoidable ambiguities in the determination of B amount to several percent, which is significant for the present-day experimental attempts to obtain B to very high precision ∼(0.1–1)%. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 10, 681–685 (25 May 1999) Published in English in the original Russian journal. Edited by Steve Torstveit.  相似文献   

5.
One of the pillars of the finance theory is the efficient-market hypothesis, which is used to analyze the stock market. However, in recent years, this hypothesis has been questioned by a number of studies showing evidence of unusual behaviors in the returns of financial assets (“anomalies”) caused by behavioral aspects of the economic agents. Therefore, it is time to initiate a debate about the efficient-market hypothesis and the “behavioral finances.” We here introduce a cellular automaton model to study the stock market complexity, considering different behaviors of the economical agents. From the analysis of the stationary standard of investment observed in the simulations and the Hurst exponents obtained for the term series of stock index, we draw conclusions concerning the complexity of the model compared to real markets. We also investigate which conditions of the investors are able to influence the efficient market hypothesis statements.  相似文献   

6.
Inequalities on eigenvalues of the Schrödinger operator are re-examined in the case of spherically symmetric potentials. In particular, we obtain:
  1. A connection between the moments of order (n ? 1)/2 of the eigenvalues of a one-dimensional problem and the total number of bound statesN n, inn space dimensions;
  2. optimal bounds on the total number of bound states below a given energy in one dimension;
  3. alower bound onN 2;
  4. a self-contained proof of the inequality for α ≧ 0,n ≧ 3, leading to the optimalC 04,C 3;
  5. solutions of non-linear variation equations which lead, forn ≧ 7, to counter examples to the conjecture thatC 0n is given either by the one-bound state case or by the classic limit; at the same time a conjecture on the nodal structure of the wave functions is disproved.
  相似文献   

7.
Dehua Wang  Tianqi Liu 《哲学杂志》2013,93(33):4264-4275
Using the closed orbit theory, we studied the effects of dielectric discontinuity on the photodetachment of H? ions. The photodetachment cross-section of H? in a medium with dielectric discontinuity was derived and calculated. The results have shown that the relative dielectric constants of the medium have a significant influence on the photodetachment of H?. If H? is kept in a medium with a relative small dielectric constant, the photodetachment cross-section of H? becomes oscillating only in a small region above the ionization threshold. However, if H? is kept in a medium with a relative large dielectric constant, the oscillation in the photodetachment cross-section becomes much stronger. Besides, the distance between H? and the dielectric dividing interface also influences the photodetachment of H?. For a given dielectric medium, the oscillation in the cross-section decreased with increasing distance between H? and the dielectric dividing interface. Therefore, we can control the photodetachment of a negative ion by changing the dielectric constant and the ion–interface distance. This study provides a new understanding of the photodetachment process of negative ions in the presence of a dielectric medium.  相似文献   

8.
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   

9.
10.
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   

11.
Based on the passive spectroscopy,the D_α atomic emission spectra in the boundary region of the plasma have been measured by a high resolution optical spectroscopic multichannel analysis(OSMA) system in EAST tokamak.The Zeeman splitting of the D_α spectral lines has been observed.A fitting procedure by using a nonlinear least squares method was applied to fit and analyze all polarization π and ±σ components of the D_α atomic spectra to acquire the information of the local plasma.The spectral line shape was investigated according to emission spectra from different regions(e.g.,low-field side and high-field side) along the viewing chords.Each polarization component was fitted and classified into three energy categories(the cold,warm,and hot components) based on different atomic production processes,in consistent with the transition energy distribution by calculating the gradient of the D_α spectral profile.The emission position,magnetic field intensity,and flow velocity of a deuterium atom were also discussed in the context.  相似文献   

12.
The study progress of NNSF in 2006 has been presented in this paper. The aim and plan of this item have been described briefly. Three test mirror exposure experiments have been done in this year. The main components of the deposited materials on the first mirror are carbon and iron analyzed by AES. The first mirror is polluted easier during glow discharge and wall processing than omhic discharge.  相似文献   

13.
The diverse words of all kinds of language are added into the World-Wide Web in an extremely complex and arbitrary manner. Behind the apparent arbitrariness topology, as we show here, there is an order hidden in the word network. By making use of Google search engine, we find that the distributions of the basic English words and Chinese characters on the web follow a universal power law. The power law exponent of rank-ordered frequency distribution is a - 0.99 for basic English words and a - 0.98 for Chinese characters. The Zipf law and page size distribution on the Web are used to explain the phenomena.  相似文献   

14.
The absorption spectra of -irradiated solutions of some acid dyes in various solvents are investigated. The characteristic times of radiation-induced destruction of dyes in the solutions are determined. It is shown that irreversible radiative discoloration of solutions occurs as a result of the interaction of the dye molecules with the oxygen-containing radicals formed in radiolysis of solvents. Practical recommendations for increasing the radiation stability of the solutions of acid dyes and for using them as detectors of a dose of hard radiation are given.  相似文献   

15.
Based on investigations of thermally stimulated conduction (TSC) in Sn2P2S6 single crystals and the effect of the surrounding gas on the character of the thermally stimulated current, it is concluded that the degree of unipolarity of ferroelectrics-semiconductors and the screening conditions play a significant and sometimes determining role in the filling of local levels, manifested in the TSC curves. By combining the standard method of TSC with the method of TSC in the photoelectret regime based on the intrinsic effect of the field, it is possible to distinguish the surface and volume attachment levels. The greatest filling of surface levels at the ends of domains is obtained from TSC curves measured in a vacuum on single-domain samples with the pulling field oriented in the same direction as the internal field and the greatest filling of volume levels is obtained with minimum unipolarity of the crystal and the creation of depleted layers on its free surface by adsorption.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 86–90, March, 1990.  相似文献   

16.
The relation between quantities that characterize the pion–nucleon and nucleon–nucleon interactions is studied with allowance for the fact that, at low energies, nuclear forces in nucleon–nucleon systems are mediated predominantly by one-pion exchange. On the basis of the values currently recommended for the low-energy parameters of the proton–proton interaction, the charged pion–nucleon coupling constant is evaluated at gπ2±/4π = 14.55(13). This value is in perfect agreement with the experimental value of gπ2±/4π = 14.52(26) found by the Uppsala Neutron Research Group. At the same time, the value obtained for the charged pion–nucleon coupling constant differs sizably from the value of the pion–nucleon coupling constant for neutral pions, which is gπ2 0/4π = 13.55(13). This is indicative of a substantial charge dependence of the coupling constant.  相似文献   

17.
A number of 1,3-diphenyl-2-thiohydantoin azo dyes were purely prepared and characterized by spectroscopic analyses. Then the azo dyes were subjected to γ-radiation doses of up to 109 rd. Results obtained indicated that the spectral bands of the investigated azo dyes suffer shifts, changes in intensity, broadening, creation of new bands and/or completely disappearance of others as a result of radiation damage. Furthermore a sequence for the relative stability of the different dyes towards gamma radiation damage was put forward.  相似文献   

18.
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   

19.
延皓  王凤聚  李长春  黄静 《中国物理 B》2017,26(4):44701-044701
In view of the complicated structure of the deflector-jet mechanism,a mathematical model based on the turbulent jet flow theory in the deflector-jet amplifier is proposed.Considering the energy transformation and momentum variation,an equation of the flow velocity distribution at the key fluid region is established to describe the morphological changes of the fluid when it passes through the deflector and jets into the receiver.Moreover,the process is segmented into four stages.According to the research results,the oil enters the deflector and impinges with the side wall.Then one part of the oil's flow velocity decreases and a high pressure zone is formed by the oil accumulation,the other part of the oil reverses out of the deflector along the side wall.Prior to entering the receiver,the flow is a kind of plane impinging jet.Virtually,the working pressure of the receiver is generated by the impact force,while the high speed fluid flows out of the receiver and forms a violent vortex,which generates negative pressure and causes the oil to be gasified.Compared with the numerical simulation results,the turbulent jet model that can effectively describe the characteristics of the deflector-jet mechanism is accurate.In addition,the calculation results of the prestage pressure characteristic have been verified by experiments.  相似文献   

20.
StudyontheAmplitude┐squaredSqueezingCharacteristicoftheBinomial┐likeStateXIUXiaofengJIANGZuohong(HeilongjiangUniveristy,Harbi...  相似文献   

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