介电测井中电参数的识别方法

本文针对水平三层介质模型的相位介电测井中的参数识别问题，给出了直接求解电参量的优化反演方法．通过数值实验，表明该方法具有稳定性好，计算精度高的优点。     

Effective antibacterial and phase change PEG/Cu2O@A-HNTs composites for melt-spun difunctional PA6 fiber

Serving as the only defensive line between pathogens and human body, personal protective equipment (PPE) is increasingly attractive among researchers because of their strong antibacterial and temperature control abilities. However, efficient antibacterial properties and regenerative thermal control simultaneously remain unexplored in PPE. Here, one-dimensional halloysite nanotubes (HNTs) modified by acid etch method, are used to synthesis a multifunctional material of PEG/Cu₂O@A-HNTs via in-situ reduction and physical adsorption which serves the above two purposes. PEG/Cu₂O@A-HNTs showed rapid bacterial inactivation and achieved 96.3% bacteriostatic rate against E. coli in only 20 ?min. Meanwhile a broad and complete inactivation spectrum included both E. coli and S. aureus following a series of antibacterial mechanisms. Moreover, adsorption of 70 ?wt% PEG by acid etch HNTs is attributed to the nearly 3 times increased specific surface area compared with native HNTs. This enabled PEG/Cu₂O@A-HNTs to attain a phase change enthalpy of 108.4 ?J/g. In addition, using PEG/Cu₂O@A-HNTs as additives, antibacterial and phase change fiber (APCF) were melt-spun. Their efficiency factor against E. coli and S. aureus was above 99.99%, and retained a temperature control ability for 180s and 272s compared with PA6 fiber in hot and frigid environments respectively.