Abstract-Quantitative Identification of the Annealing Degree of Apatite Fission Tracks Using Terahertz Time Domain Spectroscopy (THz-TDS)

Hang Wu, Shixiang Wu, Nansheng Qiu, Jian Chang, Rima Bao, Xin Zhang, Nian Liu, Shuai Liu

http://journals.sagepub.com/doi/10.1177/0003702818761668

Apatite fission-track (AFT) analysis, a widely used low-temperature thermochronology method, can provide details of the hydrocarbon generation history of source rocks for use in hydrocarbon exploration. The AFT method is based on the annealing behavior of fission tracks generated by ²³⁸U fission in apatite particles during geological history. Due to the cumbersome experimental steps and high expense, it is imperative to find an efficient and inexpensive technique to determinate the annealing degree of AFT. In this study, on the basis of the ellipsoid configuration of tracks, the track volume fraction model (TVFM) is established and the fission-track volume index is proposed. Furthermore, terahertz time domain spectroscopy (THz-TDS) is used for the first time to identify the variation of the AFT annealing degree of Durango apatite particles heated at 20, 275, 300, 325, 450, and 500 ℃ for 10 h. The THz absorbance of the sample increases with the degree of annealing. In addition, the THz absorption index is exponentially related to annealing temperature and can be used to characterize the fission-track volume index. Terahertz time domain spectroscopy can be an ancillary technique for AFT thermochronological research. More work is urgently needed to extrapolate experimental data to geological conditions.

Abstract-Water adsorption dynamics into active carbon probed by terahertz spectroscopy

Honglei Zhan,   Shixiang Wu,   Rima Bao,   Kun Zhao,   Lizhi Xiao,  Lina Ge and   Hongjie Shi  

RSC Adv., 2015, Accepted Manuscript

DOI: 10.1039/C4RA14730H
Received 17 Nov 2014, Accepted 12 Jan 2015
First published online 12 Jan 2015
http://pubs.rsc.org/en/content/articlelanding/2015/ra/c4ra14730h#!divAbstract


It is vital to characterize the adsorption dynamics in oil-gas reservoirs and pollution control industry. Terahertz (THz) spectroscopy was used to study the adsorption of the water molecules into active carbons. The absorbance at selected frequencies and the first principal component scores over the whole THz range were related to the corresponding time lengths. The collective tendency expressly tracked the dynamics of water adsorbed into active carbon pores. Therefore, THz technique can be used as a promising tool to monitor the adsorption issue in petroleum and environment fields.