The Super-Micropores in Macromolecular Structure of Tectonically Deformed Coal Using High-Resolution Transmission Electron Microscopy

2017 ◽  
Vol 17 (9) ◽  
pp. 6982-6990
Author(s):  
Sen Wang ◽  
Jienan Pan ◽  
Yiwen Ju ◽  
Kai Wang ◽  
Qinghe Niu ◽  
...  
2021 ◽  
Vol 21 (1) ◽  
pp. 772-780
Author(s):  
Liang Guo ◽  
Zhenghui Qu ◽  
Zhiwen Xue ◽  
Hao Li ◽  
Bicheng Zhang ◽  
...  

In China, most coal seams have experienced multiple phases of tectonics, which increase the complexity of the coal porosity. The responses of macromolecular structures to stress–strain environments are the key to understanding the complexity of coal porosity caused by tectonism. This study investigated the macromolecular structural response of coking coal to different stress–strain environments. The calculation and analysis of high-resolution transmission electron microscopy (HRTEM) test results for six coking coals with different deformation types and degrees were performed. The results showed that the macromolecular structure of coking coal has different responses to stress– strain environments. The lattice fringe length, curvature, and d002 parameters are not prominently governed by certain principles increasing shear and toughness. Furthermore, the lattice fringe tends to be consistent with the deformation. However, the lattice fringe during ductile deformation in the main direction is arranged nearly parallel on the plane. In shear deformation, the lattice fringes are arranged parallel in the principal direction. This phenomenon is caused by the directional screening of the macromolecular structure of coking coal by stress. Under the action of tectonic stress, the structure hindering tectonic stress is destroyed, and the structure grows in other directions gradually under the promotion of tectonic stress. As a result, the direction of the whole lattice fringe gradually converges under stress screening after tectonic stress is applied. Therefore, the direction tends to be consistent with the strengthening of the deformation. The response of the other parameters is slow, showing the coexistence of the old and new orders of direction. The directivity of the macromolecular structure of coal is an important index for reflecting the types and degrees of tectonic deformation.


Author(s):  
R. Gronsky

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.


Carbon ◽  
2017 ◽  
Vol 117 ◽  
pp. 174-181 ◽  
Author(s):  
Chang’an Wang ◽  
Thomas Huddle ◽  
Chung-Hsuan Huang ◽  
Wenbo Zhu ◽  
Randy L. Vander Wal ◽  
...  

2016 ◽  
Vol 30 (20) ◽  
pp. 1650269 ◽  
Author(s):  
Thi Giang Le ◽  
Minh Tuan Dau

High-resolution transmission electron microscopy (HR-TEM) has been used to investigate the structural properties of GeMn/Ge nanocolumns multilayer samples grown on Ge(001) substrates by means of molecular beam epitaxy (MBE) system. Four bilayers with the spacer thickness in the range between 6 nm and 15 nm and 10 periods of bilayers of Ge[Formula: see text]Mn[Formula: see text]/Ge nanocolumn are presented. A simplified 2D model based on the theory of elastic constant interactions has been used to provide reasonable explanations to the vertical self-organization of GeMn nanocolumns in multilayers.


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