Abstract: The present disclosure relates to a leather coating composition comprising or consisting of a hydrosilylation curable silicone elastomer composition designed to be used as a topcoat for a synthetic leather material, particularly a silicone-based synthetic leather composite material. A silicone coating as a topcoat for a synthetic leather material which is the cured product of the composition, methods of making the topcoat, synthetic leather material utilizing same and uses of the synthetic leather material products are also disclosed. The topcoat is designed to provide a highly crosslinked silicone matrix containing silicon-free organic micro-particles to minimize or at least decrease change in gloss after abrasion.

Abstract: A reasonable millisecond time control method for excavation blasting of a tunnel is provided, and includes: acquiring physical mechanical parameters to establish a millisecond blasting model, and designing four dimensions blasting parameters of explosive quantity, hole number, inter-hole millisecond and inter-row millisecond; simulating, based on the millisecond blasting model, a blasting process of an explosive package using blasting parameters to obtain a blasting vibration curve; obtaining single-hole blasting vibration waveforms, solving a vibration synthesis curve through a vibration synthesis theory; comparing the vibration synthesis curve with the blasting vibration curve to obtain a coupling relationship of blasting parameters; determining a target group of explosive quantity and hole numbers, determining a target millisecond through the coupling relationship of blasting parameters, and relating a millisecond blasting control strategy to control, and it is used for tunneling project to reduce cut blas