The occurrence of coal-bearing strata in a variety of coal-bearing basins of China is characterized by late tectonic deformation and remarkable spatial and geochronologic differences. The main controlling factors, which determine the tectonic framework of coalfields, include the geodynamic environment, tectonic evolution, deep structures, tectonic stress, and lithologic combination of the coal measures. The Chinese continent has experienced multi-stage tectonic movements since the Late Paleozoic. The spatial and temporal heterogeneity of its continental tectonic evolution, the complexity of its basement properties, and its stratigraphic configurations control the tectonic framework of its coalfields’ present complex and orderly patterns. The concept of coal occurrence structural units is proposed in this paper and is defined as the structural zoning of coal occurrence. China’s coalfields are divided into five coal occurrence structural areas, and the structural characteristics of the coalfields in five main coal occurrence areas throughout the country are summarized. Based on the analysis of the relationship between the structure characteristics and occurrence of coal in these coalfields, the coal-controlling structures are divided into six groups: extensional structural styles, compressional structural styles, shearing and rotational structural styles, inverted structural styles, sliding structural styles, and syn-depositional structural styles. In addition, the distribution of coal-controlling structural styles is briefly summarized in this paper.
AbstractThe behavior of cement-based materials is manipulated by chemical and physical
processes at the nanolevel. Therefore, the application of nanomaterials in civil
engineering to develop nano-modified cement-based materials is a promising research.
In recent decades, a large number of researchers have tried to improve the properties
of cement-based materials by employing various nanomaterials and to characterize the
mechanism of nano-strengthening. In this study, the state of the art progress of
nano-modified cement-based materials is systematically reviewed and summarized.
First, this study reviews the basic properties and dispersion methods of
nanomaterials commonly used in cement-based materials, including carbon nanotubes,
carbon nanofibers, graphene, graphene oxide, nano-silica, nano-calcium carbonate,
nano-calcium silicate hydrate, etc. Then the research progress on nano-engineered
cementitious composites is reviewed from the view of accelerating cement hydration,
reinforcing mechanical properties, and improving durability. In addition, the market
and applications of nanomaterials for cement-based materials are briefly discussed,
and the cost is creatively summarized through market survey. Finally, this study also
summarizes the existing problems in current research and provides future perspectives
accordingly.
In this study, Moringa oleifera seed protein-montmorillonite (MOSP-MMT) composite was synthetized using the impregnation method. The MOSP-MMT adsorbent was characterized using scanning electron microscope, X-ray diffraction, infrared spectroscopy, surface area analysis, and thermogravimetric analysis. The removal of water-soluble reactive red 2 (RR-2) from artificial wastewater by the MOSP-MMT composite was carried out in a batch system. The results indicated that RR-2 adsorption increased with contact time, and the pseudo-second-order equation was best to describe the adoption process among the three models. The RR-2 adsorption decreased from 7.60 to 5.92 mg/g as pH increased from 3.2 to 9.1 and increased from 15.2 to 17.1 mg/g as NaCl concentration increased from 0 to 30 g/L. The Freundlich isotherm model provided the better fit of the experimental data than the Langmuir model. The result showed that the MOSP-MMT composite could be a potential adsorbent for the treatment of wastewater containing RR-2.
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