An experiment has been conducted on CT-6B tokamak in order to study the effect of discharge conditions, such as filling gas pressure, toroidal field, stray magnetic fields and loop vvoltage, on the breakdown. It is found that the dependence of breakdown voltage on the vertical stray field is obviously different from that on the horizontal stray field. The main experimental results are discrepant f...
We have carried cut experiments on laser-driven shock wave propagation in a transparent target using high-speed shadowgraphy. The results of the following studies are obtained: 1) A comparision of shock wave pressures at the two wavelengths (λ =1.3μm and λ = 0.44 μm). 2) Scaling of shock wave pressures in dependence on the absorbed laser intensities of the targets.
One of the problems in surface physics which has not been solved for a long time is the atomic structure of reconstructed Si(lll)2×l surface. Basing upon the calculations on dynamics of low energy electron diffraction (LEED), we analysed the intensity-voltage curve in detail to test a lot of proposed models. The buckling π-chain model has been confirmed by our results. The atomic coordinates down ...
Systematic studies on the structure of defects in InP caused by electron irradiation are conducted basing on the experimental measurements and theoratical calculations. The introducing rates and annealing out temperatures of In and P vacancies are estimated using proper theoratical models. These calculations reveal that after room temperature irradiation only complexes may exist. It is also suppor...
Optical third harmonic radiation has been measured in reflection from Surfaces of Single crystal and ion implanted silicon samples. As was proved in our theoretical Calculation, the linearly polarized third harmonic intensity exhibits the rotational symmetry of the crystal as the crystal rotates about its surface normal. There is a critical implant etose in lightly implanted samples. The rotationa...
FTIR was employed to study doped silicon passivated by atomic hydrogen, deuterium and implanted by proton. The localized vibrational modes of [BD] pairs, 1.560 cm-1 and 1263 cm-1, were excited with different passivation conditions of atomic deuterium. This shows that there are at least two possible positions for deuterium atoms around acceptor B. IR absorption spectra of doped silicon implanted by...
Using the Green function technique, the H-F ground state energy of the symmetric Anderson lattice is caolulated. Then the correlation energy, ground state energy, local moments, charge-and Spin-fluctuations of the correlation ground State are caclulated with the local approximation. Corresponding analytical formulas are obtained for a rectangular density of state. The result indicates that local m...
The nonlinear behavior of ultrasonic absorption in glasses below 2 K is analysed by combining the two-level systems model and the infrared divergence theory. A modification of the existing tunneling two-level model of Jackie et al. is given. The Bloch equations are used as the macroscopic equations of the "magnetization" and all quantities in the equations as en-sebmble averages rather than a stat...
With the analysis of eigenvalues, it is found that a Hopf bifurcation would occur from the steady state of a dissipative three-wave interaction, so long as the contraction rate of its volume in phase space is low enough. The critical value of the contraction rate and the frequencies of the oscillation obtained from the eigenvalues are in good agreement with the results of solving the dynamk equati...
From the basic principles of statistical physics, we have obtained the more general conditions that the convolution law of the density of states of the system and its subsystems or that of the high-dimensional system and low-dimensional system is satisfiled. We also analysed the transition of densities of states from the l-dimension to the 3-dimension in the free electron and tigkt-binding periodi...
XPS was used to study the electronic structure of the amorphous rare earth alloy TbxCo1-x. We found that there is no significant difference in the band structure of the alloy and the core level spectra of Co and Tb between the amorphous and crystalline states. This implies that the charge transfer between Tb and Co is the same in the two states. The difference in magnetic properties for these stat...
The structure of lithium borovanadate (Li2O-B2O3-V2O5) glasses was studied by 11B CW-NMR technique. The fractions of BO4 and BO3 units were measured and analyzed. Basing on a FDB model, the structural model of lithium borovanadate glasses was proposed.We showed that V2O5 shared Li2O with B2O3, and combined with B2O3 in the form BVO4.5. The (N4)max are approximately constant with different K. Accor...
By calculating the vibrational entropy change during hole transition for Fe-center, it is shown that the acceptor state of Fe-center is antibonding; The enthalpy and Gibbs free energy change and their temperature dependence caused by hole transition are calculated and compared with experimental data. From the results, it is reasonably well understood that activation energy obtained by thermal emis...
The sulphur and oxygen segregation on V(100) surface is investigated in detail by AES and LEED. The relation between S and O segregation is clearly demonstrated and two new surface reconstructions, (8×1)-O and (4×l)-O,on V(100) surface are disclosed. Various superstructures on this surface under different conditions of S & O segregation are studied systematically and the relationship among these s...
The refractive indices of unpolarized KIO3 crystal in three different directions have been measured in the range of visible wavelength. The existence of type I phase matching surface in KIO3 crystal has been verified by experimental method. The optimum phase matching direc-tion in unpolarized KIO3 crystal has been found.
The finite energy resolution of EXAFS spectrometer is an important effect on EXAFS measurement. It lowers the EXAFS amplitude and the decrement in smaller k is greater than that in larger k. That causes smaller coordination number and the relative mean square displacement obtained from EXAFS data. This paper proposes a method to calculate the effect of the resolution on the structural parameters e...
Dielectric properties of one-dimensoional polymer PTS single crystal have been measured along the chain direction in the temperature rang 77-273 K. A second-order phase transition from a high temperature nonpolar state to a low temperature polar state accompanied by an anomaly in the dielectric constant is observed at 195 K. Two peaks in the dielectric loss are found at 150 K and 100 K. The result...
Applying Landau's Fermi liquid theory, we explain the superconductive critical temperature change with pressure in UBe13. The conclusion is that UBe13 is a possible P-wave superconductor. Furthermore, we find the effect of f energy levels displacement relative to Fermi energy level and s-f hybridization increase due to applying pressure are of benefit to S-wave superconductors, but not of benefit ...
We have studied (l+l)-dimensional gauge theory with the chiral fermions using the path-integral approach. Performing a non-abelian chiral change of variables and choosing a more general regularization operator, we get the exact solution of the fermion determinant. We also show that there can exist a mass generation in the theory for the vector bosons. Apart from a mass term, the solution contains ...
The formula of the elastic scattering amplitude in the Glauber theory are re-derived. If we take rectanguler optic potential as zero order approximation and Woods-Saxon optical potential as exact potential, we find that the partial integral can be performed further in the original scattering amplitude formulas. Finally, We obtain the revised scattering amplitude without angle constraint.
In this paper, a new type of quantum mechanical amplifier using transition beat is described. At room temperature, as the bandwidth of receiver is 2 KHz, the sensitivity is 5×10-15 W.