Showing papers by "Nanjing Tech University published in 1996"
TL;DR: In this article, a large-aperture high-accuracy phase-shifting digital flat interferometer that is a combination of optics, mechanics, electricity, and algorithm is described.
Abstract: A large-aperture high-accuracy phase-shifting digital flat interferometer that is a combination of optics, mechanics, electricity, and algorithm is described. The aperture size is 250 mm and a liquid surface is used as an absolute flat to eliminate system error. The accuracy is better than ?/50 (?50.6328 µm, peak-to-valley value). The tested aperture can be enlarged to 500 mm. This interferometer has been used as an optical flat standard instrument for China. The optical interferometer, phase shifter, and calibration of precision are described.
18 citations
02 Dec 1996-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this paper, low energy nitrogen (N) ions were irradiated during the epitaxial growth of GaAs using combined ion beam and molecular beam epitaxy (CIBMBE) method as a function of N + ion acceleration energy (E a ) and N+ ion beam current density ( I N ).
Abstract: Low energy nitrogen (N) ions were irradiated during the epitaxial growth of GaAs using combined ion beam and molecular beam epitaxy (CIBMBE) method as a function of N + ion acceleration energy ( E a ) and N + ion beam current density ( I N ). E a was varied from 70 to 170 eV I N from 900 pA/cm 2 to 75 nA/cm 2 . GaAs growth rate was fixed to 1 μm/h. In 2 K photoluminescence (PL) spectra of the samples with I N = 3 nA/cm 2 and E a = 70–100 eV, two sharp emissions at 1.508 eV ( X 1 ) and 1.495 eV ( X 2 ), which have been attributed to the emissions of excitons bound to isolated N atoms, and another one at 1.443 eV ( X 5 ) were observed. These results show that nitrogen (N) atom in GaAs becomes optically active as an isoelectronic impurity at least in as-grown condition. For N + ion-irradiated samples with rather high I N , e.g., with I N = 75 nA/cm 2 and E a = 100 eV, a broad emission together with multiple sharp ones were observed after furnace annealing at 750°C which were ascribed to emissions of excitons bound to nitrogen-nitrogen (NN) pairs.
6 citations
TL;DR: In this paper, a new method exactly to solve the bending of elastic thin plates with arbitrary shape was presented, where the analytic solution of the differential equation of the elastic thin plate is derived in polar coordinate, and the analytical solution is substituted into the boundary conditions of the plate with arbitrary shapes, which are then expanded along the boundary by the use of Fourier series.
Abstract: This paper presents a new method exactly to solve the bending of elastic thin plates with arbitrary shape. First the analytic solution of differential equation of elastic thin plate is derived in polar coordinate, then the analytic solution is substituted into the boundary conditions of elastic thin plate with arbitrary shape. The boundary equations are expanded along the boundary by the use of Fourier series, all unknown coefficients can be decided. The results are exact.
2 citations