[en] The main purpose of this work is to study an inverse source and inverse coefficient problem for a piezoelectric equation in one dimension which is of great interest in nanomaterials. Based on Carleman estimates, local Hölder stability estimates for the inverse source and coefficient problem are obtained respectively provided that additional measurement data are given on an interior sub-domain with non-vanishing measure. Furthermore, two numerical algorithms based upon conjugate-gradient method are proposed for the corresponding inverse source and coefficient problems. Numerical examples are presented to demonstrate the effectiveness of the proposed algorithms. (paper)

[en] To reveal the mechanisms of flame propagation through the hardly volatile metal dust clouds clearly, the flame propagating through zirconium particle clouds has been examined experimentally. A high-speed video camera was used to record the propagation process of the flame. Combustion zone temperature was detected by a fine thermocouple. Based on the experimental results, structure of flame and combustion courses of zirconium particles were analyzed, the combustion propagation in zirconium dust was investigated, and the velocity and temperature characteristics of the combustion zone were also elucidated. The combustion zone propagating through zirconium particle clouds consists of luminous particles. Particle concentration plays an important role in the combustion zone propagation process. With the increase of zirconium particle concentration, the maximum temperature of the combustion zone increases at the lower concentration, takes a maximum value, and then decreases at the higher concentration. It is also found that the propagation velocity of the combustion zone has a linear relationship with its maximum temperature.