Deformation failure law and control countermeasures of deep buried weakly cemented soft rock roadway

In order to study the deformation-failure law of deep buried weakly cemented soft rock roadway and determine reasonable control countermeasures, taking the south main return laneway of Yuwu Coal Mine as an example, the strain softening model parameters were adjusted to reflect the argillization and volume expansion characteristics of weakly cemented soft rock. The stress, deformation and failure evolution of surrounding rock during roadway excavation were numerically analyzed. On this basis, the combined support control countermeasure of “bolt-shotcrete + grouting + inverted arch” was obtained. The results show that the radial displacement of roof, floor and two sides of surrounding rock in deep buried weakly cemented soft rock roadway will reach 734.2 mm, 490.3 mm and 549.6 mm after tunneling 24 m forward. At the same time, the depth of loose zone will increase to 5.6 m, 2.8 m and 3.0 m respectively, while the depth of plastic zone will expand to 9.5 m, 8.8 m and 13.7 m respectively. After adopting the combined support of “bolt-shotcrete + grouting + inverted arch”, the radial displacement and plastic zone depth of roadway will be reduced by 91%-94% and 71%-74%, respectively, and the time to reach stability is greatly shortened

Azimuthally polarized, passively Q-switched Yb-doped fiber laser

An azimuthally polarized and passively Q-switched ytterbium-doped fiber laser was demonstrated. With the involvement of a single lens inside the laser resonator, a birefringent crystal was used as the polarization discriminator, and a Cr4+ :YAG crystal acted as the saturable absorber and also the output coupler. For the simplicity and low optical loss of the resonator cavity, this fiber laser emitted azimuthally polarized pulse with a high slope efficiency of 72.6% and high average power of 4.11 W. The laser pulse had 132-ns duration and 112-kHz repetition rate at the absorbed pump power of 6.40W. (C) 2015 Elsevier B.V. All rights reserved

Engineering Amorphous CoNiRuOx Nanoparticles Grown on Nickel Foam for Boosted Electrocatalytic Hydrogen Evolution

Designing efficient and cost-effective electrocatalysts is crucial for the large-scale development of sustainable hydrogen energy. Amorphous catalysts hold great promise for application due to their structural flexibility and high exposure of active sites. We report a novel method for the in situ growth of amorphous CoNiRuOx nanoparticle structures (CoNiRuOx/NF) on a nickel foam substrate. In 1 m KOH, CoNiRuOx/NF achieves a current density of 10 mA/cm2 with a hydrogen evolution reaction (HER) overpotential of only 43 mV and remains stable for over 100 h at a current density of 100 mA/cm2. An alkaline electrolyzer assembled with CoNiRuOx/NF as the cathode delivers a current density 2.97 times higher than that of an IrO2||Pt/C electrode pair at the potential of 2 V and exhibits excellent long-term durability exceeding 100 h. Experimental results reveal that the combined replacement and corrosion reactions facilitate the formation of the amorphous CoNiRuOx structure. This work provides valuable insights for developing efficient and scalable amorphous catalysts

High Glucose Suppresses Osteogenic Differentiation and Induces Mitochondrial Dysfunction in Osteoblasts via SIRT1/RECQL4 Axis; A Laboratory Study Using Mouse Cells

Background: Diabetes mellitus has an adverse effect on human bones, which is a risk factor for osteoporosis. The aim of this study was to explore the mechanism of the effects of high glucose (HG) on the osteogenic differentiation of osteoblasts. Methods: In this study, mouse MC3T3-E1 cells were cultured in high glucose level at 30 mM with 24.5 mM mannitol and 5.5 mM glucose as control. Plasmid circular deoxyribonucleic acids (pcDNAs) and small interference ribonucleic acids (RNAs) were transfected for functional analysis of RecQ helicase-like 4 (RECQL4) and sirtuin 1 (SIRT1). The viability, alkaline phosphatase (ALP) activity, and OCN (provide in full) concentration was measured via methyl thiazolyl tetrazolium (MTT), colorimetric, enzyme-linked immunosorbent assay (ELISA) assays. Mitochondrial functions were assessed by mitochondrial membrane potential (MMP) and the levels of adenosine triphosphate (ATP), glutathione (GSH), and malondialdehyde (MDA). Quantitative reverse-transcription polymerase chain reaction or western blot were conducted to detect the gene or protein expression. RECQL4 acetylation assay was performed and the interaction between RECQL4 and SIRT1 was detected via co-immunoprecipitation assay. Results: The effects of HG on downregulating cell viability, the levels of osteogenic differentiation-related markers (ALP and OCN), p53 phosphorylation, ATP and GSH as well as RECQL4 and apoptosis-related factors (Cytochrome C and Cleaved caspase-3) upregulating MMP loss and MDA content were reversed following RECQL4 over expression (p < 0.01). Sirtuin 1 (SIRT1) over expression promoted the viability and the levels of ALP and OCN, while silencing RECQL4 did the opposite (p < 0.05) and caused a reversion in HG-treated osteoblasts (p < 0.01). Additionally, silencing SIRT1 inhibited the acetylation of RECQL4 (p < 0.01) and the interaction between SIRT1 and RECQL4. Conclusions: HG repressed the osteogenic differentiation and downregulated MMP via SIRT1/RECQL4 axis in osteoblasts