Jian Peng

To alleviate the problems of casing collapse induced by the coupling effect of rock salt creep and casing wear, the effects of salt creep, attrition rate and casing abrasive position on the equivalent stress on casings in non-uniform in-situ stress field is analyzed by finite-difference model with worn casing, cement and salt formation. It indicates that, creep reduces the yield strength of worn casing to a certain extent; Equivalent stress on casings is bigger and more non-uniform when the abrasion is more serious; Wear position obviously changes the distribution of equivalent stress on casing, and when the wear located along the direction of the minimum in-situ stress, equivalent stress on casing could be the largest that leads to the casing being failed more easily. Equivalent stress on casings increases gradually with creep time increasing and will get to balance in one year or so; In addition, new conclusions are obtained which are different from before: the maximum equivalent stress on casings is in the direction of the minimum horizontal stress, only when the attrition rate of the casing is little; otherwise, it is not. This method could help to improve the wear prediction and design of casings.

This paper introduces a wideband resistive electromagnetic (EM) absorber surface that is based on a tightly coupled dipole structure with polarization insensitivity. By employing broadband tightly coupled dipoles as the fundamental units, the resulting array is capable of effectively absorbing spatial EM energy, while the incorporated resistors facilitate energy dissipation. To comprehensively understand the operational principles of the absorber surface, an equivalent circuit model is proposed in this study. To validate the absorber surface's absorption capabilities, a 290 mm × 290 mm EM absorber surface was manufactured and subjected to rigorous testing. The test results unequivocally demonstrated that the absorber surface achieved an absorption efficiency surpassing 90% within the frequency range of 3.38 to 10.3 GHz. Furthermore, the proposed absorber surface showcased remarkable insensitivity to changes in the incident wave's polarization angle. As the incident angle varied from 0° to 45°, the absorption efficiency remained consistently stable within the designated operating frequency band.

Along with the arrival of the digital economy, the country’s financial industry ushered in the development of the “golden period,” under this background financial services, technology and others continue to optimize and perfect. To meet the needs of social development, the relevant positions need a large number of high-quality, skilled financial professionals, but the current personnel training model has been unable to achieve the established goals. Therefore, in the context of the new era, vocational colleges need to deeply analyze the new requirements of the digital economy on the ability of professional talents, then discuss the restrictive factors existing in the current training of professional talents, and put forward effective reform measures to improve the quality of talent training and effectively deepen the reform of professional teaching.