Filters
Results 1 - 10 of 1314
Results 1 - 10 of 1314.
Search took: 0.023 seconds
Sort by: date | relevance |
AbstractAbstract
[en] Absolute diffraction efficiencies of a transmission grating at a photon energy of 844 eV have been calibrated on synchrotron radiation source. With the aid of grating model, all structure parameters of the grating are obtained and absolute diffraction efficiencies for soft X-rays in the range of 100-2000 eV are calculated and discussed
Primary Subject
Record Type
Journal Article
Journal
Acta Physica Sinica; ISSN 1000-3290;
; v. 47(4); p. 613-618

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] The author report a method of carbon nanotube and nano-polyhedron growth in graphite surface by 60 keV Ar+ ion beam bombardment. High resolution transmission electron microscopy (HRTEM) reveals that the nanostructures range from ∼20 nm to ∼0.4 μm in size and the distance between carbon layers in multilayer walls is 0.34 nm. Based on HRTEM images, the authors propose a growth model of 'combined carbon polyhedron'
Record Type
Journal Article
Journal
Acta Physica Sinica; ISSN 1000-3290;
; v. 47(6); p. 960-964

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] Based on the investigation of molecular dynamics simulation, a deposition dynamics model of incident atom in vapor phase deposition was established. The atomistic processes of Au/Au (100) epitaxial growth in the early stage were simulated by using kinetic Monte Carlo method and ad-atomic diffusion model with local environment. The change of film growth mode with temperature was investigated. The authors revealed that the monomer diffusion plays a very important role in the film growth. At the temperature as low as that at which the monomer cannot diffuse in large scale, adatom nucleation and island formation depends on the increase of adatom density. With the increase of temperature, the film growth mode depends on the competition between in-plane diffusion and inter-layer diffusion of monomers
Record Type
Journal Article
Journal
Acta Physica Sinica; ISSN 1000-3290;
; v. 49(2); p. 297-305

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] Within the framework of isospin-dependent quantum molecular dynamics model, isotopic distributions in the reactions of 112Sn + 112Sn and 124Sn + 124Sn at 40 and 100 MeV/u are investigated. It is found that the isotopic distribution has a significant isospin effect at 40 MeV/u, but the isospin effect disappears at 100 MeV/u. By investigating mechanical and chemical instabilities at different energies, the authors find that the energy dependence of isospin effects on isotopic distributions results from the competition between mechanical instabilities and chemical instabilities at different energies
Primary Subject
Record Type
Journal Article
Journal
Acta Physica Sinica; ISSN 1000-3290;
; v. 50(6); p. 1040-1045

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] On the basis of the energy spectra, the angular and Z distributions of the fragments emitted at forward and intermediate angle region in 25 MeV/u 40Ar + 115In reaction, the evolution of emission mechanisms of fragments with the emission angles of the fragments in the laboratory system and the charge numbers of the fragments is discussed. The model of modified quantum molecular dynamics (MQMD) is employed to investigate the angular and Z distribution of the fragments. The theoretical calculations are in good agreement with the experimental data in general. But in the forward angles the yield of the fragments is underestimated by MQMD model while in the case of the intermediate angle region, the calculated result is higher than the experimental data for the fragments whose charge numbers are in the vicinity of the projectile. The angular and charge distributions of the fragments are also compared with the statistical model of GEMINI. It is found that a small proportion of the statistical evaporation component exists in the forward angle region while in the intermediate angle region, this statistical evaporation component shows a little increase. With the decrease of the fragment charge number, the non-equilibrium intermediate-velocity component goes up step by step and plays a leading role while the equilibrium evaporation one diminishes gradually
Primary Subject
Record Type
Journal Article
Literature Type
Numerical Data
Journal
Acta Physica Sinica; ISSN 1000-3290;
; v. 49(5); p. 868-874

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] By adopting the Bohm type thermal diffusivity coefficient which is applicable to JET, considering the effect of the α particle anomalous diffusion and the dynamic feedback heating, and using the energy transport equations of electron and ion, the plasma temperature profiles of deuterium-tritium (D-T) burning are studied under a given plasma density profile. Some results are obtained: the Bohm type thermal conductivity increases from the center of plasma to the boundary; in order to sustain D-T burning, the dynamic feedback heating power must be present, otherwise, the burning would be extinguished; the power coupling coefficient of α particle with the bulk plasma is less than one in the central part of the plasma, and much larger than one in the outer part; the stronger the α particle anomalous diffusion, the higher the central ion temperature. This is due to the smaller thermal diffusivity coefficient in the central part and the dynamic heating power to increase because of the lower central electron temperature; the energy amplifier factor Q under the Bohm type is smaller than under other types, therefore, the prospect of the Tokamak reactor operation model based on Bohm type is pessimistic
Primary Subject
Record Type
Journal Article
Journal
Acta Physica Sinica; ISSN 1000-3290;
; v. 48(12); p. 2266-2274

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] Au was deposited on PVF (Polyviny formal) film which was kept at 253 K to grow Au submonolayer film. It is found that there are special areas whose morphology differs from other's experiment in which metal was deposited on single crystal. In these areas especially big clusters were found and they were surrounded by empty bands. The deduction that is caused by variation of local coefficient is proved by a modified DDA (Deposition-Diffusion-Aggregation) model which includes edge diffusion. The authors also argue that the relationship between cluster diffusion coefficient DS, and particles numbers S which the cluster contains should be exponential for Au cluster on PVF film instead of power-dependent in original DDA model
Record Type
Journal Article
Journal
Acta Physica Sinica; ISSN 1000-3290;
; v. 48(6); p. 1126-1131

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] The charged particle system's energy level separation in the vertical direction of the magnetic field is considered, according to Boltzmann distribution. Several equations are obtained. The effects are obvious under the condition of low temperature and high intensity magnetic field. Several equations of plasma MHD are corrected
Primary Subject
Record Type
Journal Article
Journal
Acta Physica Sinica; ISSN 1000-3290;
; v. 47(12); p. 2005-2011

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] X-ray spectra, angular distributions of X-ray fluxes and evolutions of X-ray spectra from the front and the rear of gold foil target with different thickness have been measured on 'Xingguang' laser facility, in which the gold foil targets were irradiated by smoothing 1.053 μm laser beam. The processes of laser and radiation ablation to gold foil have been studied. Quantitative X-ray spectra from the front and the rear of gold foil under several conditions such as different foil thickness, different laser power densities and X-ray emission angles have been obtained. At the same time, radiative heat wave has also been observed from the evolutions of X-ray spectra emitted from the rear of gold foils of different thickness
Primary Subject
Record Type
Journal Article
Journal
Acta Physica Sinica; ISSN 1000-3290;
; v. 49(12); p. 2408-2413

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] In order to offset the collisional effects reduced by using finite-size particles, β particle clouds are used in particle simulation codes (β is the ratio of charge or mass of modeling particles to real ones). The method of impulse approximation (strait line orbit approximation) is used to analyze the scattering cross section of β particle clouds plasmas. The authors can obtain the relation of the value of a and β and scattering cross section (a is the radius of β particle cloud). By using this relation the authors can determine the value of a and β so that the collisional effects of the modeling system is correspondent with the real one. The authors can also adjust the values of a and β so that the authors can enhance or reduce the collisional effects fictitiously. The results of simulation are in good agreement with the theoretical ones
Primary Subject
Record Type
Journal Article
Journal
Acta Physica Sinica; ISSN 1000-3290;
; v. 49(8); p. 1513-1519

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