Study on Characteristics of Failure and Energy Evolution of Different Moisture-Containing Soft Rocks under Cyclic Disturbance Loading.

During the coal mining process in soft rock mines with abundant water, the rock mass undergoes cyclic loading and unloading at low frequencies due to factors such as excavation. To investigate the mechanical characteristics and energy evolution laws of different water-containing rock masses under cyclic disturbance loading, a creep dynamic disturbance impact loading system was employed to conduct cyclic disturbance experiments on various water-containing soft rocks (0.00%, 1.74%, 3.48%, 5.21%, 6.95%, and 8.69%). A comparative analysis was conducted on the patterns of input energy density, elastic energy density, dissipated energy density, and damage variables of different water-containing soft rocks during the disturbance process. The results indicate that under the influence of disturbance loading, the peak strength of specimens, except for fully saturated samples, is generally increased to varying degrees. Weakness effects on the elastic modulus were observed in samples with 6.95% water content and saturated samples, while strengthening effects were observed in others. The input energy density of samples is mostly stored in the form of elastic strain energy within the samples, and different water-containing samples adapt to external loads within the first 100 cycles, with almost identical trends in energy indicators. Damage variables during the disturbance process were calculated using the maximum strain method, revealing the evolution of damage in the samples. From an energy evolution perspective, these experimental results elucidate the fatigue damage characteristics of water-containing rock masses under the influence of disturbance loading.

A Robust Biomimetic Superhydrophobic Coating with Superior Mechanical Durability and Chemical Stability for Inner Pipeline Protection.

Durable superhydrophobic anti-erosion/anticorrosion coatings are highly demanded across various applications. However, achieving coatings with exceptional superhydrophobicity, mechanical strength, and corrosion resistance remains a grand challenge. Herein, a robust microstructure coating, inspired by the cylindrical structures situated on the surface of conch shell, for mitigating erosion and corrosion damages in gas transportation pipelines is reported. Specifically, citric acid monohydrate as a pore-forming agent is leveraged to create a porous structure between layers, effectively buffering the impact on the surface. As a result, the coating demonstrates remarkable wear resistance and water repellency. Importantly, even after abrasion by sandpaper and an erosion loop test, the resulting superhydrophobic surfaces retain the water repellency. The design strategy offers a promising route to manufacturing multifunctional materials with desired features and structural complexities, thereby enabling effective self-cleaning and antifouling abilities in harsh operating environments for an array of applications, including self-cleaning windows, antifouling coatings for medical devices, and anti-erosion/anticorrosion protection, among other areas.

Occurrence of microplastics pollution in the Yangtze River: Distinct characteristics of spatial distribution and basin-wide ecological risk assessment.

The widespread presence of microplastics (MPs) in the Yangtze River, the third longest river in the world, has drawn increasing attention. Although numerous studies have been conducted recently to investigate and analyze the MPs exposure to the surface water of the river, most merely focus on a certain part of the Yangtze River, and knowledge of MPs based on the basin-wide is still scattered. This article reveals the spatial distribution characteristics of MPs in the Yangtze River from the whole watershed scale. Among the five areas in the basin, the upstream and the midstream were demonstrated to contain more MPs (3598.6 particles/m3 and 3226.8 particles/m3). The obtained results suggested the MP presented in the entire watersheds was uneven and the 'hotspots' occurred, where the MPs concentrations were relatively higher than the surrounding. The discharging of the wastewater treatment plants along the river, the locations of dams, and the stability and fragment of MPs, were demonstrated to be the important driving factors in the spatial distribution of MPs and leading to the appearance of the MP 'hotspots' in the Yangtze River, but were previously overlooked. It is the first study to evaluate the ecological risk of MPs exposure to the surface water of the Yangtze River with multiple assessment methods, taking not only abundance but also morphological characteristics, polymer composition and toxic effect into account. More importantly, based on the multiple individual MPs risk assessment methods, we developed the BetaMP method which achieves a comprehensive assessment of MP risk in basin-wide by taking multiple MP characteristics into account for the first time. This is conducive to better understanding the environmental impacts of MPs pollution in the different regions of the river.

Numerical analysis of dispersion characteristics of underwater gas-oil two-phase leakage process.

Fatigue failure, third-party destruction and internal corrosion may easily trigger gas and oil leakage during the operation of submarine multiphase pipelines. In order to analyze the underwater gas-oil plume development and migration law, a 3D model based on coupled Eulerian-Lagrangian numerical approach is proposed. The model is validated by laboratory experiment and the dynamic dispersion process of gas-oil plume in a large scale shallow sea environmental is further explored. Influencing factors such as leak location, leak size and water depth, flow pattern are investigated. The simulated results show that leak location affects the gas-oil plume migration behaviors by influencing the leakage amount. Water depth significantly affects gas-oil migration and the separation of gas plume and oil plume is gradually apparent as water depth increases. This study fills in the gap of ignoring the influence of flow pattern previously and is expected to help build more accurate emergency response guidelines.

Experimental study on particle movement and erosion behavior of the elbow in liquid-solid flow.

Recent investigations into the erosion of elbow junctions predominantly focus on identifying and predicting peak erosion points. Notably, these studies rely heavily on computational fluid dynamics methods, a valid approach but limited by its lack of empirical physical data. Additionally, the majority of these studies concentrate on the extrados, or outer curve of the elbow, neglecting the intrados or the inner curve. To provide a more comprehensive understanding of particle movements and the micro-mechanics of erosion on the elbow intrados, this study utilizes advanced observational technologies. High-speed camera technology, coupled with scanning electron microscopy, is employed to capture and record particle motion and micro-erosion patterns. The erosion rate is then estimated via the weight-loss method. The findings suggest that in low-speed liquid-solid flows (2.5 m/s), particles released from the intrados side of the elbow inlet exhibit a significant trajectory deviation from the centreline at an elbow angle of 60° from the inlet. Particles released from the extrados deviate towards the intrados side at an elbow angle of 30°. Secondary flow contributes to particle acceleration, unexpected trajectory deviation within the elbow, and an upward inclination in erosion on the intrados. The presence of partially overlapping scratches and cracks suggests that continuous ploughing and material fracturing are significant contributors to the micro-mechanics of erosion. When comparing the intrados and extrados, the extrados exhibits longer and shallower scratches, indicating a smaller impact angle. This research provides a more comprehensive understanding of particle trajectories and erosion patterns within elbow junctions during liquid-solid flows, offering new insights into the mechanisms underpinning these processes.

Effect of double carbon chains on enhanced removal of phenol from wastewater by amphoteric-gemini complex-modified bentonite.

A novle amphoteric-gemini complex-modified bentonite was prepared with a gemini surfactant ethylene bis (tetradecyl dimethyl ammonium chloride) (EB) on the basis of the bentonite modified by amphoteric modifier dodecyldimethyl betaine (BS). The surface and structural characteristics of modified bentonite were characterized by X-ray diffraction (XRD), specific surface area (SBET), scanning electron microscopy (SEM), Fourier infrared spectroscopy (FTIR), total carbon (TC) and total nitrogen (TN). In addition to studying the enhanced effect of gemini surfactants on phenol adsorption by kinetics and equilibrium adsorption, the influences of modification ratio, pH, temperature and ionic strength were investigated. Results showed that BS + EB complex modification increased the interlayer spacing (IS), TC and TN of bentonite (BT), and SBET decreased with the increase in its total modification ratio. The adsorption of phenol on modified bentonite reached equilibrium in 20 min, and the adsorption capacities were in the order of BS+50 EB (BS+50% CEC EB)>BS+100 EB > BS+150 EB > BS+25 EB > BS > BT. The adsorption capacities of phenol on BS + EB complex modified bentonite (CMB) increased by 9.98-15.96 and 1.19-3.35 times compared with those on BT and BS single modified bentonite (SMB), respectively. The phenol adsorption capacities decreased with the increases in temperature and pH, while it increased with the augment in ionic strength. This study revealed that double carbon chains increased the organic carbon content more effectively than single carbon chains at low complex modification ratios, thus promoting the adsorption of phenol by hydrophobic partitioning on the bentonite surface.

Key Technologies of Pure Hydrogen and Hydrogen-Mixed Natural Gas Pipeline Transportation.

Thanks to the advantages of cleanliness, high efficiency, extensive sources, and renewable energy, hydrogen energy has gradually become the focus of energy development in the world's major economies. At present, the natural gas transportation pipeline network is relatively complete, while hydrogen transportation technology faces many challenges, such as the lack of technical specifications, high safety risks, and high investment costs, which are the key factors that hinder the development of hydrogen pipeline transportation. This paper provides a comprehensive overview and summary of the current status and development prospects of pure hydrogen and hydrogen-mixed natural gas pipeline transportation. Analysts believe that basic studies and case studies for hydrogen infrastructure transformation and system optimization have received extensive attention, and related technical studies are mainly focused on pipeline transportation processes, pipe evaluation, and safe operation guarantees. There are still technical challenges in hydrogen-mixed natural gas pipelines in terms of the doping ratio and hydrogen separation and purification. To promote the industrial application of hydrogen energy, it is necessary to develop more efficient, low-cost, and low-energy-consumption hydrogen storage materials.

Co-adsorption capabilities and mechanisms of bentonite enhanced sludge biochar for de-risking norfloxacin and Cu2+ contaminated water.

Various bentonite-sludge biochar composites were fabricated by a sequence of loading and pyrolysis for the simultaneous removal of norfloxacin (NOR) and copper (Cu2+) from an aqueous solution. The morphology and characteristics of obtained composites were reflected through cation exchange capacity (CEC), BET specific surface area (SBET), SEM, XRD, FTIR and XPS. The isothermal adsorption results showed that Sips adsorption model fitted better for the adsorption of NOR and Cu2+ during co-adsorption. The theoretical maximum adsorption capacity of BT:2 SB (the mass ratio of bentonite to sludge is 1:2) for NOR and Cu2+ was 89.36 mg g-1 and 104.10 mg g-1 at 25 °C in the co-adsorption system. The thermodynamic results showed the capture of NOR and Cu2+ was spontaneous, accompanied by an endothermic reaction with different randomness. In the co-adsorption system, the two were antagonistic to each other due to competition for the adsorption sites of hydroxyl, carboxylic acid and negatively charged provided by bentonite-sludge biochar. This study suggests that using natural mineral as a pyrolysis improver for sludge biochar can product the value-enhanced biochar for simultaneous removal of antibiotic and metal contaminants.

The complete mitochondrial genome of Phlaeoba tenebrosa (Orthoptera: Acridoidea: Acrididae).

The complete mitochondrial genome of Phlaeoba tenebrosa was sequenced. Its 15,648 bp nucleotides encode 37 typical mitochondrial genes and contain 73.8% AT. All 13 mitochondrial protein coding genes (PCGs) share the start codon ATN, except for cox1 (CCG start codon). The usual termination codons (TAA or TAG) and incomplete stop codons (T or TA) are found from 13 protein-coding genes. The most frequent amino acids in the PCGs are Leucine (14.02%), Serine (9.64%), Phenylalanine (9.13%), Isoleucine (10.44%), and the total content of these amino acids was 43.23%. All tRNA genes could be folded into the typical cloverleaf secondary structure, except trnS(AGN) lacking of the dihydrouridine arm. The sizes of the large and small rRNA genes are 1319 bp and 841 bp, respectively. The AT content of the A + T-rich region is 82.6%.

[Expression and clinical significance of vascular endothelial growth factor in human non-small cell lung cancer].

BACKGROUND: To investigate the expression of vascular endothelial growth factor (VEGF) and its relation to clinical characteristics and prognosis of non-small cell lung cancer (NSCLC), and to study the possible mechanism of VEGF. METHODS: The expression of VEGF and intratumoral microvascular density (MVD) were determined in 96 NSCLC tissues by SP immunohistochemical method. RESULTS: VEGF was mainly stained in the cytoplasm of tumor cells. The positive rate of VEGF expression was 64.6% in 96 patients. The positive rate of VEGF expression was related to stages (P=0.041), but not to other clinical characteristics of NSCLC (P > 0.05). The expression of VEGF in high MVD group (80.4%) was significantly higher than that in low MVD group (46.7%) (P=0.001). The patients with positive VEGF expression had a significantly shorter survival duration than those with negative VEGF expression (P < 0.01). By Cox proportional hazard model analysis, the expression of VEGF and clinical stage were considered the independent predictors for the prognosis of NSCLC. CONCLUSIONS: The results suggest that VEGF plays an important role in the angiogenesis of NSCLC, and that detection of VEGF expression may be helpful to predict prognosis of NSCLC.

[Construction of bioprosthetic heart valve with viable cells].

The ideal valve substitute should have cellular viability. Cryopreserved allograft has cellular viability in some degree, but the quantity, viability and function of the cells are affected by some preexistent factors such as chemical injury, hypoxia during valve processing and injury at the time of implantation. Early cellular autolysis and apoptosis take place not long after implantation, the implanted valve thus loses significant capacity to grow, remodel, or exhibit active metabolic functions. The viable donor cells are antigenic and capable of eliciting immune response, including antigenic and antigen-specific T cells. Calcification appears to originate in residual nonviable cells and their fragments. Proteinases released from endothelial and fibroblast cells of allograft heart valve will lead to the destruction of the valve matrix. One of the focuses of creating an ideal heart valve is the progressive recellularization of the valve matrix by the autologous cells. The acellular valve matrix, after being recellularized, has two characters: cellular viability and normal cellular function, which are the bases of creating ideal bioprosthetic valve with the potentiality of growing, repairing and remodeling.