[Analyzing moiré pattern spectra based on the mutual transform between signals' waveform in time domain and their spectra in frequency space].

The mutual evolving processes of signals' waveforms and their spectra were numerically analyzed in time and frequency domains. The purpose was to research the essential relation between the signals' waveforms and their spectra. Then, the mutual transform principle was applied to analyze moiré pattern spectra, acquiring phase distribution information of the pattern.

[Numerical simulation of a new nonlinear iteration tomography based on deflection spectra].

A new deflection tomography was suggested and verified with a simulated flow field. The deflection programs for projection and inverse-projection were produced based on optical principle of refraction and mathematical, physical significance of tomography. With the authors' home-made simple self-correlative algebraic reconstruction technique (SSART), the program system for the new deflection tomography was worked out and named Nonlinear Iteration Tomography Based on Deflection Spectra.

[Extracting projections from laser moire interference spectra].

Laser Moire Interference spectra of rocket exhausted plumes were analyzed. Projections for reconstruction were figured out, and air density distribution was reconstructed. Moire deflectograms of the plumes were produced and captured with a home-made, wide-range, high-sensitivity Moire deflectometer.

[Algebraic reconstruction techniques and improvement studied with spectroscopy].

The present article focuses on improving algebraic reconstruction technique (ART) for optical computerized tomography (OCT). With spectroscopy, a series of traditional ARTs were analyzed in detail, then a new improved ART was developed. The new ART was named simple self-correlative algebraic reconstruction technique (SSART).

[Tracking the process reconstructing original signal with sampled data by spectroscopy].

With spectroscopy, the principle and process of sampling and reconstructing a continuous-time signal are discussed. A symmetrical frequency-finite spectrum function F (omega) is constructed with three modified rise-cosine pulses. Its corresponding time-domain signal f(t) is worked out theoretically.

[Simple self-correlative algebraic reconstruction technique].

A new improvement was brought forward in algebraic reconstruction technique (ART), named simple self-correlative algebraic reconstruction technique (SSCART), and its reconstructive result was discussed in detail. With numerical simulation technique, both ART and SSCART were numerically simulated with computer, and discussed in terms of simulated result and reconstructive accuracy with error indexes such as mean-square error (MSE), absolute value error (AVE) and peak error (PE). As a result, the accuracy of SSCART was markedly improved.

[Analyzing the effect of field frequencies on reconstructive accuracy of rebuilt field with spectroscopy].

The field to be reconstructed was simulated with numerical simulation technique. The effect of a three-dimensional field's characteristics, especially, its frequency components, on the reconstructive accuracy was discussed with spectroscopy. A double-peaked field model was built with Gaussian function, and its frequency components were analyzed by Fourier transform.

[Analyzing the methods to smooth field reconstructed by algebraic reconstruction technique with spectroscopy].

The effects of filters and filtering methods on the field reconstructed by algebraic reconstruction technique (ART) is discussed with spectroscopy. The field to be constructed was simulated with numerical simulation technique. The effects of many kinds of filters and filtering methods on the field reconstructed by ART were analyzed with spectroscopy.

[Doppler effect on width of characteristic line in plasma induced by pulsed laser ablating Al].

Aluminum (Al) plasma was induced with a pulsed Nd: YAG laser beam ablating Al target in Ar. Time-resolved information of the plasma radiation was taken with time-resolved technique, and the spectra of the radiation were recorded with an optical multi-path analyzer (OMA III ), whereupon, time-resolved spectra of the plasma radiation induced by pulsed laser were acquired. Based on the experiment data, Al resonant double lines, Al I 396.

[Study on time-resolved spectra shape of aluminum plasma's characteristic radiation].

Aluminum plasma was obtained with a Nd:YAG pulsed laser beam ablating target aluminum. The radiation information of the plasma was recorded on a time and space resolution basis. So the time-resolved spectra of Al plasma were obtained with a time delay of 10 to 10,000 ns.

[Spatial profile of radiation from the plasma induced by laser-ablated aluminum].

The plasma was acquired with a pulsed Nd:YAG laser beam ablating aluminum. The pulse energy was set up to 145 mJ per pulse. Ar was used as surrounding gas with the pressure of 100 kPa.

[Investigation on the transition probability of the aluminum resonant double lines].

In order to obtain the aluminum resonant double lines, Al I 396.15 nm and Al I 394.40 nm, we have recorded the time-resolved spectra of the plasma induced by Nd:YAG laser ablating metal aluminum in Ar, under the Ar ambient pressure 10 kPa, at 0.