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Single ionization of helium atoms by energetic fully stripped carbon ions

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Chinese physics B 2015年第10期24卷 154-159页

作者： Ebrahim Ghanbari-Adivi Sadjad Eskandari department of physics Faculty of SciencesUniversity of Isfahan

A four-body distorted wave approximation is presented for theoretical investigations of the single ionization of groundstate helium atoms by fully stripped carbon ions at impact energies of 2 MeV/amu and 100 MeV/amu. The nine-dimensional integrals for the partial quantum-mechanical transition amplitudes of the specified reaction are reduced to some analytical expressions or one-dimensional integrals over real variables. Fully differential cross sections（FDCSs） are calculated and compared with their experimental values as well as the results obtained from other theories. Despite the simplicity and quickness of the proposed quadrature, the comparison shows that the obtained results are in reasonable agreement with the experiment and are compatible with those of other complicated theories.

关键词： ion-impact ionization four-body distorted wave approximation transition amplitude fully differ- ential cross sections

New initial condition of the new agegraphic dark energy model

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Chinese physics B 2013年第3期22卷 561-566页

作者：李云鹤张敬飞张鑫 department of physics College of SciencesNortheastern University

The initial condition Ωde（zini）=n^2（1＋zini）^-2/4 at zini = 2000,widely used to solve the differential equation of the density of the new agegraphic dark energy（NADE） Ωde,makes the NADE model a single-parameter dark-energy cosmological ***,we find that this initial condition is only applicable in a flat universe with only dark energy and pressureless *** fact,in order to obtain more information from current observational data,such as the cosmic microwave background（CMB） and the baryon acoustic oscillations（BAO）,we need to consider the contribution of *** this situation,the initial condition mentioned above becomes *** overcome this shortcoming,we investigate the evolutions of dark energy in matter-dominated and radiation-dominated epochs,and obtain a new initial condition de（zini）=n2（1＋zini）-2（1＋F（zini））2/4 at z ini = 2000,where F（z）≡Ωr0（1＋z）/[Ωm0＋Ωr0（1＋z）] with Ωr0 and Ωm0 being the current density parameters of radiation and pressureless matter,*** revised initial condition is applicable for the differential equation of Ωde obtained in the standard Friedmann-Robertson-Walker（FRW） universe with dark energy,pressureless matter,radiation,and even spatial curvature,and can still keep the NADE model as a single-parameter *** the revised initial condition and the observational data of type Ia supernova（SNIa）,CMB,and BAO,we finally constrain the NADE *** results show that the single free parameter n of the NADE model can be constrained tightly.

关键词： new agegraphic dark energy model initial condition single-parameter model observational constraints

New agegraphic dark energy as a rolling tachyon

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Chinese physics B 2010年第1期19卷 600-605页

作者：崔晶磊张莉张敬飞张鑫 department of physics College of SciencesNortheastern University

Combining the general relativity and the uncertainty relation in quantum mechanics, the energy density of quantum fluctuations of space-time can be viewed as dark energy. The so-called agegraphic dark energy model is just based on this viewpoint, in which the age of the universe is introduced as the length measure. Recently, the new agegraphic dark energy model was proposed, where the dynamical dark energy is measured by the conformal age of the universe. On the other hand, scalar-field dark energy models like tachyons are often regarded as an effective description of some underlying theory of dark energy. In this paper, we show that the new agegraphic dark energy can be described completely by a tachyon scalar-field. We thus reconstruct the potential and the dynamics of the tachyon scalar-field, according to the evolution of the new agegraphic dark energy.

关键词： new agegraphic dark energy tachyon reconstruction

Using the Hg_xMg_(1-x)Te ternary compound as a room temperature photodetector: The electronic structure, charge transport, and response function of the energetic electromagnetic radiation

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Chinese physics B 2018年第5期27卷 143-149页

作者： Ghasemi Hasan Mokhtari Ali department of physics Faculty of SciencesShahrekord University

In the present work, firstly, a first-principles study of the structural, electronic, and electron transport properties of the HgxMg1-xTe（HMT） ternary compound is performed using the ABINIT package and the results are compared with Cd0.9Zn0.1 Te（CZT） as a current room-temperature photodetector. Next, the response functions of Hg0.6Mg0.4Te and Cd0.9Zn0.1Te under electromagnetic irradiation with 0.05 Me V, 0.2 MeV, 0.661 MeV and 1.33 MeV energies are simulated by using the MCNP code. According to these simulations, the Hg0.6Mg0.4Te ternary compound is suggested as a good semiconductor photodetector for use at room temperature.

关键词： band gap charge-carrier transport photodetector density functional theory

Two Special Solutions of the Non-ideal Magnetohydrodynamics

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Chinese physics Letters 2000年第5期17卷 382-384页

作者： FENG Xue-Shang LIU Yong WEI Feng-Si YE Zhan-Yin Laboratory of Numerical Study for Heliospheric physics Center for Space Sciences and Applied ResearchChinese Academy of SciencesBeijing 100080

A special transformation is found to solve the Magnetohydrodynamic equations,by which two classes of exactanalytic time-dependent solutions of magnetic annihilation for incompressible magnetic fluid have been *** solutions derived here possesses scaling property with time t as the scale *** find that the currentcan perform the soliton-like behaviour in the case of asymmetric *** relevant evolution characteristics inthe process of magnetic annihilation are also revealed.

关键词： annihilation soliton behaviour

Candidate chiral nuclei in bromine isotopes based on triaxial relativistic mean field theory

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Science China(physics,Mechanics & Astronomy) 2019年第1期62卷 56-62页

作者： Bin Qi Hui Jia Chen Liu ShouYu Wang Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and Physics Institute of Space Sciences Shandong University

Following the observation of candidate chiral doublet bands in ^(78,80)Br, triaxial deformations with corresponding configurations in odd-odd bromine isotopes have been investigated using adiabatic and configuration-fixed constrained triaxial relativistic-meanfield calculations with an aim of finding the boundary of chirality in the chain of Br isotopes. Several minima with triaxial deformation and the proper particle-hole configuration were obtained in ^(74,76,78,80,82)Br, where the chiral doublet bands have the possibility of occurrence. Furthermore, the possible existence of multiple chiral doublet(MχD) bands is demonstrated in ^(74,76,78,80,82)*** to explore the chirality and MχD properties of Br isotopes are conducted to verify the predictions.

关键词： chiral doublet bands relativistic mean field bromine isotopes

Investigation of electrons inside the satellite by the Geant4 simulation

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Science China(Technological sciences) 2011年第9期54卷 2271-2275页

作者： LI XiaoCan CHEN HongFei HAO YongQiang ZOU Hong SHI WeiHong Institute of space physics and Applied Technology School of Earth and Space Sciences Peking University Beijing 100871 China

The measurement of the electron radiation inside the satellite is important for engineering and space environment *** particle radiation detectors (PRD) on board CBERS-1 and CBERS-2 made great contribution to understanding of the space ***,what is the radiation relationship between inside and outside the satellite? The Monte Carlo simula-tion with Geant4 was implemented to study the *** boundaries of the energy bins of 0.5 and 2 MeV were precisely corresponding to outside energies of 0.99 and 2.52 MeV,*** the changes of the energy bins,the fluxes inside were smaller than those of the corresponding bins *** spectrum inside the satellite was harder than that *** indicator was that the flux ratio of the high energy bin to the low energy bin increased more than 20% from outside to *** geometric factor (GF) relates to the incident energy of *** using the AE-8 model to derive the incident spec-trum,the GFs of the low and high energy bins were 1.15 and 0.70 cm2 sr,*** of the low energy bin was larger than that of the high energy *** they were both smaller than the previous *** was due to the scattering,straggle and shielding effects.

关键词： electron radiation in satellite electron detector Monte Carlo simulation Geant4

Two-Point Resistance on the Centered-Triangular Lattice

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Chinese physics Letters 2018年第2期35卷 6-10页

作者： M.Q.Owaidat A.A.Al-Badawi J.H.Asad Mohammed Al-Twiessi department of physics Al-Hussein Bin Talal University department of physics Faculty of SciencesTaibah University department of physics Faculty of Arts and SciencesPalestine Technical University

The resistance between any two lattice points in an infinite, centered-triangular lattice of equal resistors is determined using the lattice Green function method. It is shown that the two-point resistance on the centered-triangular lattice is expressed in terms of the resistance of a triangular lattice. Some exact values for the resistance near the origin of the lattice are presented. For large separation between lattice points the asymptotic forms of the resistance are calculated.

关键词： Two-Point Resistance on the Centered-Triangular Lattice

Effect on Landau damping rates for a non-Maxwellian distribution function consisting of two electron populations

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Chinese physics B 2013年第3期22卷 358-365页

作者： M.N.S.Qureshi S.Sehar H.A.Shah J.B.Cao space Science Institute Beihang University department of physics Government College University

In many physical situations where a laser or electron beam passes through a dense plasma,hot low-density electron populations can be generated,resulting in a particle distribution function consisting of a dense cold population and a small hot *** of such low-density electron distributions can alter the wave damping rate.A kinetic model is employed to study the Landau damping of Langmuir waves when a small hot electron population is present in the dense cold electron population with non-Maxwellian distribution *** of plasma from Maxwellian distributions significantly alters the damping rates as compared to the Maxwellian *** damping is found for highly nonMaxwellian distributions as well as plasmas with a higher density and hot electron *** of weak damping is also established when the distribution contains broadened flat tops at the low energies or tends to be *** results may be applied in both experimental and space physics regimes.

关键词： Landau damping Langmuir waves two electron populations non-Maxwellian distribution function