Filters
Results 1 - 10 of 12499
Results 1 - 10 of 12499.
Search took: 0.028 seconds
Sort by: date | relevance |
Wang Tao; Gao Zi-You; Zhao Xiao-Mei, E-mail: zygao@bjtu.edu.cn, E-mail: xmzhao@bjtu.edu.cn2012
AbstractAbstract
[en] Considering the effect of multiple flux difference, an extended lattice model is proposed to improve the stability of traffic flow. The stability condition of the new model is obtained by using linear stability theory. The theoretical analysis result shows that considering the flux difference effect ahead can stabilize traffic flow. The nonlinear analysis is also conducted by using a reductive perturbation method. The modified KdV (mKdV) equation near the critical point is derived and the kink—antikink solution is obtained from the mKdV equation. Numerical simulation results show that the multiple flux difference effect can suppress the traffic jam considerably, which is in line with the analytical result. (general)
Primary Subject
Source
Available from http://dx.doi.org/10.1088/1674-1056/21/2/020512; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Chinese Physics. B; ISSN 1674-1056;
; v. 21(2); [8 p.]

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Tu Zhan-Chun, E-mail: tuzc@bnu.edu.cn2012
AbstractAbstract
[en] This review reports several key advances on the theoretical investigations of efficiency at maximum power of heat engines in the past five years. The analytical results of efficiency at maximum power for the Curzon—Ahlborn heat engine, the stochastic heat engine constructed from a Brownian particle, and Feynman's ratchet as a heat engine are presented. It is found that: the efficiency at maximum power exhibits universal behavior at small relative temperature differences; the lower and the upper bounds might exist under quite general conditions; and the problem of efficiency at maximum power comes down to seeking for the minimum irreversible entropy production in each finite-time isothermal process for a given time. (review)
Primary Subject
Source
Available from http://dx.doi.org/10.1088/1674-1056/21/2/020513; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Chinese Physics. B; ISSN 1674-1056;
; v. 21(2); [10 p.]

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Yan Ren-Peng; Yu Xin; Chen De-Ying; Chen Fei; Li Xu-Dong; Ma Yu-Fei; Yu Jun-Hua, E-mail: yanrenpeng@yahoo.cn2012
AbstractAbstract
[en] The thermal effect and the heat generation in diode-end-pumped continuous-wave 914-nm Nd:YVO4 lasers are investigated in detail. A theoretical model of a diode end-pumped solid-state laser is constructed to analyse the influence of fractional thermal loading on the thermal effect in the Nd:YVO4 laser based on finite element analysis. The thermal focal lengths and the end-surface deformations of laser rods in Nd:YVO4 quasi-three-level and four-level lasers are measured and compared with the results obtained by ordinary interferometry for the demonstration of higher thermal loading in 914-nm laser. Finally the fractional thermal loading in the Nd:YVO4 quasi-three-level laser is calculated by matching the experimental and the simulated end deformations. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Source
Available from http://dx.doi.org/10.1088/1674-1056/21/2/024208; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Chinese Physics. B; ISSN 1674-1056;
; v. 21(2); [7 p.]

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Wu Yan; Ye Hui-Liang; Zhang Jing-Tao; Shao Chu-Yin, E-mail: jtzhang@siom.ac.cn2012
AbstractAbstract
[en] Using a nonperturbative quantum electrodynamics theory of high-order harmonic generation (HHG), a scaling law of HHG is established. The scaling law states that when the atomic binding energy Eb, the wavelength λ and the intensity I of the laser field change simultaneously to kEb, λ/k, and k3I, respectively. The characteristics of the HHG spectrum remain unchanged, while the harmonic yield is enhanced k3 times. That HHG obeys the same scaling law with above-threshold ionization is a solid proof of the fact that the two physical processes have similar physical mechanisms. The variation of integrated harmonic yields is also discussed. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Primary Subject
Source
Available from http://dx.doi.org/10.1088/1674-1056/21/2/024210; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Chinese Physics. B; ISSN 1674-1056;
; v. 21(2); [6 p.]

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Wang Qing-Guo; Su Liang-Bi; Li Hong-Jun; Zheng Li-He; Xu Xiao-Dong; Tang Hui-Li; Jiang Da-Peng; Wu Feng; Xu Jun, E-mail: xujun@mail.shcnc.ac.cn2012
AbstractAbstract
[en] The Er-single-doped and Er/Ce-codoped La3Ga5SiO14 polycrystalline powders are synthesized by the solid-phase synthesis method. The room-temperature luminescence spectra of the samples are investigated. The Near-infrared-region spectroscopic properties of Er3+ ions in the La3Ga5SiO14 systems are analysed with Judd-Ofelt theory and rate equations. The effective deactivating effect of Ce3+ ions on Er3+ ions is confirmed. (condensed matter: structural, mechanical, and thermal properties)
Source
Available from http://dx.doi.org/10.1088/1674-1056/21/2/026101; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Chinese Physics. B; ISSN 1674-1056;
; v. 21(2); [7 p.]

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Li Li; Liang Jiu-Qing; Shao Jian-Li; Duan Su-Qing; Li Yan-Fang, E-mail: duan_suqing@iapcm.ac.cn2012
AbstractAbstract
[en] By molecular dynamics simulations employing an embedded atom model potential, we investigate the fcc-to-bcc phase transition in single crystal Al, caused by uniform compression. Results show that the fcc structure is unstable when the pressure is over 250 GPa, in reasonable agreement with the calculated value through the density functional theory. The morphology evolution of the structural transition and the corresponding transition mechanism are analysed in detail. The bcc (011) planes are transited from the fcc (111-bar) plane and the (11-bar1) plane. We suggest that the transition mechanism consists mainly of compression, shear, slid and rotation of the lattice. In addition, our radial distribution function analysis explicitly indicates the phase transition of Al from fcc phase to bcc structure. (condensed matter: structural, mechanical, and thermal properties)
Source
Available from http://dx.doi.org/10.1088/1674-1056/21/2/026402; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Chinese Physics. B; ISSN 1674-1056;
; v. 21(2); [6 p.]

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] The damping and frequency-shift in Landau mechanism of a quadrupole mode in a disc-shaped rubidium Bose—Einstein condensate are investigated by using the Hartree—Fock—Bogoliubov approximation. The practical relaxations of the elementary excitations and the orthometric relation among them are taken into account to obtain advisable calculation formula for damping as well as frequency-shift. The first approximation of Gaussian distribution function is employed for the ground-state wavefunction to suitably eliminate the divergence of the analytic three-mode coupling matrix elements. According to these methods, both Landau damping rate and frequency-shift of the quadrupole mode are analytically calculated. In addition, all the theoretical results agree with the experimental ones. (general)
Primary Subject
Source
Available from http://dx.doi.org/10.1088/1674-1056/23/9/090311; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Chinese Physics. B; ISSN 1674-1056;
; v. 23(9); [7 p.]

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Lu Hai-Chang; Zhai Yue-Yang; Pan Rui-Zhi; Yang Shi-Feng, E-mail: yangshifeng111@126.com2014
AbstractAbstract
[en] Based on the experimental device which is a non-uniform magnetic field to trap an atom, we show how to obtain a certain velocity of a Bose gas by controlling the magnetic coils. By comparing the relationship of the different current supply and delay time versus the ultimate velocity of the atom, we theoretically predict the method of accelerating the gases to an expected velocity. This method is of great convenience and significance for the applications in cold atom physics and precision measurements. (atomic and molecular physics)
Primary Subject
Source
Available from http://dx.doi.org/10.1088/1674-1056/23/9/093701; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Chinese Physics. B; ISSN 1674-1056;
; v. 23(9); [4 p.]

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Lin Hai; Xu Di; Yang He-Lin; Pantoja, M. F.; Garcia, S. G., E-mail: linhai.ccnu@gmail.com2014
AbstractAbstract
[en] Graphene has been considered as a promising material which may find applications in the THz science. In this work, we numerically investigate tunable photonic crystals in the THz range based on stacked graphene/dielelctric layers, a complex pole—residue pair model is used to find the effective permittivity of graphene, which could be easily incorporated into the finite-difference time domain (FDTD) algorithm. Two different schemes of photonic crystal used for extending the bandgap have been simulated through this FDTD technique. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Primary Subject
Source
Available from http://dx.doi.org/10.1088/1674-1056/23/9/094203; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Chinese Physics. B; ISSN 1674-1056;
; v. 23(9); [4 p.]

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Gao Xu-Peng; Jiang Ye-Hua; Liu Yang-Zhen; Zhou Rong; Feng Jing, E-mail: jiangyehua@kmust.edu.cn2014
AbstractAbstract
[en] Density functional theory (DFT) is applied to investigate the stability and mechanical properties of NbxCy compounds. The structures of NbxCy compounds are optimized, and the results are in good agreement with previous work. The calculated results of the cohesive energy and the formation enthalpy of NbxCy show that they are thermodynamically stable structures, except for Pmc21-Nb2C. The mechanical properties such as the bulk modulus, Young's modulus, the shear modulus, and Poisson's ratio are obtained by Voigt—Reuss—Hill approximation. The results show that the Young's modulus and shear modulus of NbC are larger than other NbxCy compounds. The mechanical anisotropy is characterized by calculating several different anisotropic indexes and factors, such as universal anisotropic index (AU), shear anisotropic factors (A1, A2, A3), and percent anisotropy (AB and AG). The surface constructions of bulk and Young's moduli are illustrated to indicate the mechanical anisotropy. The hardness of NbxCy compounds is also discussed in this paper. The estimated hardness for all NbxCy compounds is less than 20 GPa. (condensed matter: electronic structure, electrical, magnetic, and optical properties)
Primary Subject
Source
Available from http://dx.doi.org/10.1088/1674-1056/23/9/097704; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Chinese Physics. B; ISSN 1674-1056;
; v. 23(9); [8 p.]

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
1 | 2 | 3 | Next |