Classification and Controlling Factors of Different Types of Pore Throat in Tight Sandstone Reservoirs Based on Fractal Features—A Case Study of Xujiahe Formation in Western Sichuan Depression,Pore Structure and Fractal Characteristics of Inter-Layer Sandstone in Marine–Continental Transitional Shale: A Case Study of the Upper Permian Longtan Formation in Southern Sichuan Basin, South China,Computational analysis of a class of singular nonlinear fractional multi-order heat conduction model of the human head | Scientific Reports,Genesis and microscopic characteristics of tight reservoirs in the Fengcheng Formation, at the southern margin of the Mahu Sag - ScienceDirect,Computational analysis of a class of singular nonlinear fractional multi-order heat conduction model of the human head | Scientific Reports