نتایج جستجو برای: neutron density
تعداد نتایج: 452104 فیلتر نتایج به سال:
The neutron-to-proton density ratio at the nuclear periphery was determined for six targets from the yield of nuclei with mass (At21) generated by antiproton annihilation on targets with mass number At . A new setup allowed us to measure this yield for nuclei with half-lives down to 6 s. The experiment confirmed the negative correlation between the peripheral neutron-to-proton density ratio and...
Hydrodynamical simulations of neutron star cores, based on a two fluid description in terms of a neutron-proton superfluid mixture, require the knowledge of the Andreev-Bashkin entrainment matrix which relates the momentum of one constituent to the currents of both constituents. This matrix is derived for arbitrary nuclear asymmetry at zero temperature and in the limits of small relative curren...
The work of J. A. Wheeler in the mid 1960’s showed that for smooth equations of state no stable stellar configurations with central densities above that corresponding to the limiting mass of ‘neutron stars’ (in the generic sense including hybrids) were stable. Accordingly, there has been no reason to expect that a stable degenerate family of stars with higher density than the known white dwarfs...
A polarised-neutron diffraction experiment on [Co(NH3)5(H20)][Cr(CN)6] shows the unexpected features of spin populat ions on the cobalt ((0.5(2) e) and the "ammine" hydrogen (0.8(1) e in total) atoms. A local density approximation DV-Xa calculation on a unit that models the molecular geometry in the crystal returns features that are broadly in agreement with the experiment. The calculation also...
Low-temperature single-crystal neutron and X-ray diffraction data were collected for bullvalene (Figure 1). X —N Fourier and multipole static deformation electron density maps were calculated and compared. Atomic mean-square-displacement parameters were analysed in the framework of the rigid-body motion model and the residual amplitudes (UOBS — t/TLS) were graphically interpreted. The prelimina...
Background: To evaluate the effects of hyperthermia (HT) on the frequency of chromosomal aberrations induced by a low dose of neutron or γ-rays in human peripheral blood lymphocytes. Materials and Methods: Blood samples were exposed to HT (41.5°C for 30 and 60min, 43°C for 15 and 30min), 10 cGy neutron or γ-rays, HT + neutron/γ, and neutron/γ + HT. After standard cell culture, harvestin...
Background: Neutron contamination is produced in electron beams of linac when tooth or dental materials are located in the path of beam. Objective: This study aims to determine the neutron dose contamination from different dental restoration materials in electron mode of a linac. Material and Methods: In this experimental study, the neutron dose contamination was calculated in the p...
The neutron star crust, the 1 kilometer region on the surface composed of nuclei and superfluid neutrons, is the physical location of the majority of the phenomena observed in neutron stars. The composition of the crust is a fundamental input for the evolution of isolated and accreting neutron stars, and is important for the description of rp-process nucleosynthesis, gravitational waves generat...
In order to achieve a thermal neutron beam for neutron radiography applications, a new neutron collimator has been designed, installed and characterized at Tehran Research Reactor (TRR). TRR is a 5 MW, open pool and light water coolant reactor with seven beam tubes. Neutron collimator that is an important part of neutron radiography system was installed in the six inch E beam tube. Collimator d...
The radiation pressure of a radio pulsar does not necessarily disrupt a surrounding disk. The position of the inner radius of a thin disk around a neutron star, determined by the balance of stresses, can be estimated by comparing the electromagnetic energy density generated by the neutron star as a rotating magnetic dipole in vacuum with the kinetic energy density of the disk. Inside the light ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید