To investigate the changes in strength and deformation of blast load-damaged sandstone roof plate under cyclic loading unloading conditions at different confining pressures, a triaxial device was used to carry out graded tests on specimens with degrees damage, test results were summarized. The effects blast-load-induced pressure stage strength, cohesion, internal friction angle, residual strain volumetric analyzed. (1) Compared that undamaged specimen 0 MPa, peak stress reductions...

Carbon dots (CDs) are carbon-based zero-dimensional nanomaterials with characteristic sizes of less than 10 ​nm. Recently, bioactive CDs have made remarkable achievements in wound healing, bone and cartilage repair, neural regeneration, myocardium regeneration owing to their unique physicochemical properties excellent biocompatibility, which significantly promoted the advancement tissue engineering. Herein, we summarize applications First, briefly introduce characteristics synthesis methods...

Micro(nano)plastics (MNPs) are emerging pollutants that can adsorb in the environment and biological molecules ultimately affect human health. However, aspects of adsorption intracellular proteins onto MNPs its effects cells have not been investigated to date. The present study revealed 100 nm polystyrene nanoplastics (NPs) could be internalized by THP-1 specifically adsorbed proteins. In total, 773 NPs with high reliability were identified using proteomics approach analyzed via...

Abstract Plant secondary metabolites can protect organisms against oxidative stress caused by adverse environmental conditions. Cinnamomum camphora (L.) J. Presl contains plentiful terpenoids and is subdivided into 5 chemotypes. To develop natural antioxidants using the plant terpenoids, terpenoid composition antioxidant abilities of methanol, ethyl acetate, n-hexane petroleum ether extracts from linalool eucalyptol chemotypes were investigated, solvent effects on in vitro activity 8 main...

Abstract To increase the efficiency of deep-hole blasting driving in mine rock tunnels, an innovative pattern wedge cutting with hole-inner delay was proposed. First, mechanisms conventional and patterns were theoretically investigated. The results showed that resistance from large upper blocks clamping action surrounding major challenges methods. For pattern, under conversion spatial distribution release sequence energy, first charge can strengthen breaking mass create a new free surface,...

The structural stability of engineering rock mass under dynamic disturbance is directly associated with the fracture mechanics properties in practice. Fully understanding rock’s mechanical behavior and crack evolution caused by stress concentration at tip load can offer useful insight into mechanism. A test using split-Hopkinson pressure bar (SHPB) system was performed on a single prefabricated fissure sandstone centrally cracked Brazilian disk (CCBD) specimens. Based theory one-dimensional...

To study the particle size distribution and energy variation law of hard coal under a load, an impact compression test specimens different loading conditions was carried out using Φ50 mm diameter Separate Hopkinson Press Bar (SHPB) system. We implemented theory dynamic rock to establish calculation expression crushing dissipation, we established Weibull model body analyze velocity in relation consumption. The results demonstrate that due original states specimens, damage static action is...

Rocks in deep coal mines are usually varying degrees of damage state before they destabilized by impact loads such as rock bursts. For the problem mechanical properties and energy evolution damaged rocks under loads, authors use static with different cyclic load thresholds to act on sandstone specimens make them distinct damage. Then, mechanics system (MTS-816) Split Hopkinson pressure bar (SHPB) employed perform uniaxial compression dynamics tests sandstones The results show that, from...

In view of the devastating outcomes fires and explosions, it is imperative to research dynamic responses concrete structures at high temperatures. For this purpose, effects strain rate temperatures on tension behavior energy characteristics high-strength were investigated in paper. Dynamic tests conducted after exposure 200, 400, 600 °C by utilizing a 74 mm diameter split Hopkinson pressure bar (SHPB) apparatus. We found that quasi-static tensile strength gradually decreased damage degree...

The propagation law of blast stress waves in jointed rock masses is closely related to the characteristics joint filling medium. water content and thickness medium affect wave surface. Based on similarity theory, mortar-red clay-mortar composite specimens with different moisture contents (36%, 39%, 42%, 45%) thicknesses (3 mm, 6 9 mm) were prepared red clay as dynamic uniaxial compression test specimen under strain rates was carried out by using a variable cross-section split Hopkinson bar...

Abstract Summary: The phase‐morphology inversion in two blend systems of polystyrene/poly(methyl methacrylate) (PS/PMMA) and polystyrene/poly( ε ‐caprolactone) (PS/PCL) has been studied after their thin films were prepared on glass substrates by spin‐coating from a co‐solvent tetrahydrofuran (THF). Phase‐contrast microscopy (PCM), scanning‐electron (SEM) equipped with energy dispersive X‐ray spectroscopy (EDS), atomic force (AFM) used to obtain information the morphology during heat...

Deep-hole bench blasting is the primary method for aggregate extraction in mines. However, factors such as complex geological conditions and suboptimal parameters often result uneven rock fragmentation high fines content. This not only increases cost energy consumption of subsequent processing but also has adverse environmental implications. In this study, based on Changjiu Shenshan limestone mining project China, large-scale experiments were conducted to investigate influence properties...

To overcome the problems of poor cutting effects in hard rock roadways, a cut blasting technique with large diameter charges was developed; that is, holes employ 50 mm blast and 45 explosive sticks, while other adopt 42 35 sticks. First, effect charge on damage range cavity formation analyzed. Next, simulation wedge for different diameters conducted to reveal stress wave developments compare field intensities. Finally, tests were verify viability this technique. The results indicate can...

In order to study the impact of blasting vibration subway tunnels on adjacent buildings, taking tunnel mining method construction section between Zhifang Street Station and Metro Town Wuhan Line 27 as engineering background, scheme is optimized by reducing maximum single charge, multi-section densifying surrounding holes. The HHT wavelet analysis are used evaluate advantages disadvantages optimization from perspective energy. results show that peak velocity significantly reduced frequency...

Smooth surface blasting control technology is aimed at the rock body until it left with a smooth and to protect from damage; current air spaced axial uncoupled charge radial continuous are effective charging structures for blasting. Reserved spacing can effectively reduce blast wave peak pressure of explosive gas, improving quasi-static gas under action fracture seam quality. In order ensure effect blasting, small-diameter light holes more often used; development drilling machinery, use...