Abstract Deep mining stress increase and thick hard rock layer endowment drive body fissure expansion, leading to sudden fracture of the roof plate accidents. The slab 11,129 working face in Zhangji Mine is a 16 m sandstone composite slab, whose compressive strength reaches 89.8 MPa. hardness high, its bearing capacity it difficult collapse. fall. If does not fall time, will lead energy accumulation itself, make two roadways show drastic mine pressure, which risk coal wall appearing slice...

A comprehensive understanding of the failure behavior and mechanism coal is a prerequisite for dealing with dynamic problems in mining space. In this study, under uniaxial compressive loads were experimentally numerically investigated. The experiments conducted using split Hopkinson pressure bar (SHPB) system. results indicated that typical lateral axial at lower loading rates totally smashed higher rates. further fractography analysis fracture fragments load caused by tensile brittle...

The computer-generated hologram (CGH) is a method for calculating arbitrary optical field interference patterns. Iterative algorithms CGHs require built-in trade-off between computation speed and accuracy of the hologram, which restricts performance applications. Although non-iterative algorithm quicker, does not meet expectations. We propose phase dual-resolution network (PDRNet) based on deep learning generating phase-only holograms with fixed computational complexity. There are no...

The abuse and irrational use of tetracyclines (TCs) in human medicine animal husbandry has become a serious concern, affecting the ecological environment health. aim this study was to develop sensitive selective method using fully automatic solid-phase extraction coupled with ultra-performance liquid chromatography–tandem mass spectrometry for determination twelve TCs water. Four isotope-labeled internal standards were used correct matrix effects. Several parameters efficiency systematically...

Multiseam longwall mining‐induced strata deformation and fracture propagation patterns are different from those of single‐seam mining. This difference is due to interaction the caved zones as a result mining activity at coal seams, which severely impacts formation subsidence permeability after multiseam Understanding this phenomenon great importance in order predict reliably, evaluate risk water inrush take suitable preventive measures, determine locations for placing gas drainage boreholes....

To obtain the autoclave-level mechanical properties using in situ consolidation of thermoplastic composites by automated fiber placement (AFP) with high efficiency is focus recent research. Different heat resources were utilized to pursue improved and deposition rates but yet not very satisfactory. In this article, E-glass fiber/polypropylene laminates, manufactured ultrasonic vibration–assisted AFP (UAFP) autoclave, compared means crystallization. The interfacial bonding mechanism was...

In order to study the influence of interconnected defects on rock breaking effect under blast load, relevant explosion experiment was carried out by prefabricating cracks plexiglass plates (PMMA), and propagation mechanism load studied from length level. The dynamic caustic line system finite element analysis software were combined analyze stress intensity factor, velocity crack tip, full-field specimen; results show that with radial wave direction as axis symmetry, two symmetrical angles...

The problem of strong ground pressure caused by thick and hard roofs in coal mine stopes has become more prominent. Blasting roof cutting relief are effective technical ways to solve this engineering problem. key achieving is the evolution penetration cracks between blasting holes a mining stress environment. To problem, research on environment being conducted. Along with specific examples, mechanical effect dynamic load surrounding rock medium analyzed using methods field investigation,...

The creep characteristics of the key unit rock in a slope potential slip surface play an important role evolution slip. In this research, systematic restrictive shear experimental study was conducted to investigate surface. A new plastic nonlinear model (PFY model) developed characterize progressive-failure reflected process rock. variable-parameter established reflect and describe whole two failure mechanisms rock, which can provide reference base for prediction time constitutive equations...

Due to rapid urbanization and climate change, cities face hidden drought risks. A single index may inadequately reflect urban meteorological drought. The indicator weight combination method does not fully consider correlation weight. This study constructed an evaluation system developed the Composite Fuzzy Matter Element Meteorological Comprehensive Index (CFEMCI) by combining moment estimation weighting model. Analyzing Zhengzhou City from 2000 2019, CFEMCI effectively captured events, with...

Z-pin technology, as a promising through-thickness reinforcement, offers an efficient solution for the weak composite parts joints, especially large integrated structures. This paper presents two-dimensional finite element model to analyze enhancing efficiency of Z-pins T-joints. The modeling used new parameter definition method delamination growth simulation in Z-pinned joining interface via regional cohesive zone model. was validated by experiments unpinned and T-joints under web pullout...

This study combined theoretical analysis, physical simulation, and numerical simulation to discuss the influences of structural evolution motion characteristics a hard roof during thickening coal seam mining on working face pressure. Results showed that with roof, settlement curve low-level strata was stepwise wave slope, high-level shifted from “V-shaped” distribution pattern parabola under full seam. When thickness relatively small, space expanded increase in due “masonry beam” structure...

Aiming at the mining disaster of a thick hard roof, based on analysis instability influence this study constructs bearing mechanical model roof by using theory and obtains distribution equation energy accumulation, release equation, dynamic load response hydraulic support in working face, as well characteristics putting forward technical countermeasures for strong pressure control face. This research shows that 1) larger overburden suspension span more serious state accumulation evolution;...