•Laser 3D printing technology is employed to fabricate CoCrFeMnNi HEA.•Fine BCC phase is found to distribute at the grain boundaries of the FCC matrix.•Printed HEA exhibits an outstanding combination ...of high strength and ductility.
Due to their superior properties, high-entropy alloys (HEAs) are considered as novel structural materials that can substitute conventional alloys. From the viewpoint of future applications, it is important to explore methods for producing complex shaped and homogeneous HEAs. In this study, laser 3D printing technology is employed to fabricate CoCrFeMnNi HEA. The microstructure and mechanical properties of laser 3D printed HEA are also evaluated. An equiaxed-to-columnar transition structure can be observed in the melt pool of the printed sample. The fine BCC phase is found to distribute at the grain boundaries of the FCC matrix, which is the major phase of the printed sample. The printed HEA exhibits an outstanding combination of high strength and excellent ductility.
Transition metals and their oxide materials have been widely employed to fabricate superhydrophobic surfaces, not only because of their surface topography with controllable microstructures leading to ...water-repellence, diverse adhesion even tun- able wettability, but also due to a variety of special properties like optical performance, magnetism, anti-bacterial, transparency and so on. At the meantime, biomimetic superhydrophobic surfaces have attracted great interest from fabricating hierarchical micro-/nano-structures inspired by nature to imitate creature＇s properties and many potential applications, including self-cleaning, antifogging, antireflection, low drag and great stability and durability. In this review, natural surfaces and biomimetic materials with special wettability are introduced by classification according to the similar microstructure of mor- phology, like array structure, sheet overlapped structure, high density hairs and seta shaped structure. Not only do we exhibit their special performances, but also try to find out the true reasons behind the phenomenon. Then, the recent progress of a series of superhydrophobic transition mental and their oxide materials, including TiO2, ZnO, Fe304, CuO, Ag, Au and so on, is pre- sented with a focus on fabricating methods, microstructures, wettability, and other properties. As followed, these superhydro- phobic surfaces can be applied in many fields, such as oil/water separation, self-cleaning, photo-controlled reversible wet- tability, surface-enhanced Raman scattering, antibacterial, anticorrosion, and synthesis of various applications. However, few of them have been applied in practical life. Hence, we discuss the remaining challenges at present and the development tendency in future at the end of this article. This review aims to present recent development of transition metals and their oxides applied in biomimetic superhydrophobic surfaces about fabrication, microstructure, water repellence, various properties, and potential applications.
The globally recognized need to advance more sustainable agriculture and food systems has motivated the emergence of transdisciplinary solutions, which include methodologies that utilize the ...properties of materials at the nanoscale to address extensive and inefficient resource use. Despite the promising prospects of these nanoscale materials, the potential for large-scale applications directly to the environment and to crops necessitates precautionary measures to avoid unintended consequences. Further, the effects of using engineered nanomaterials (ENMs) in agricultural practices cascade throughout their life cycle and include effects from upstream-embodied resources and emissions from ENM production as well as their potential downstream environmental implications. Building on decades-long research in ENM synthesis, biological and environmental interactions, fate, transport and transformation, there is the opportunity to inform the sustainable design of nano-enabled agrochemicals. Here we perform a screening-level analysis that considers the system-wide benefits and costs for opportunities in which ENMs can advance the sustainability of crop-based agriculture. These include their on-farm use as (1) soil amendments to offset nitrogen fertilizer inputs, (2) seed coatings to increase germination rates and (3) foliar sprays to enhance yields. In each analysis, the nano-enabled alternatives are compared against the current practice on the basis of performance and embodied energy. In addition to identifying the ENM compositions and application approaches with the greatest potential to sustainably advance crop production, we present a holistic, prospective, systems-based approach that promotes emerging alternatives that have net performance and environmental benefits.
This study investigates the influences of urban land cover on the extreme rainfall event over the Zhengzhou city in central China on 20 July 2021 using the Weather Research and Forecasting model at a ...convection-permitting scale 1-km resolution in the innermost domain (d3). Two ensembles of simulation (CTRL, NURB), each consisting of 11 members with a multi-layer urban canopy model and various combinations of physics schemes, were conducted using different land cover scenarios: (i) the real urban land cover, (ii) all cities in d3 being replaced with natural land cover. The results suggest that CTRL reasonably reproduces the spatiotemporal evolution of rainstorms and the 24-h rainfall accumulation over the key region, although the maximum hourly rainfall is underestimated and displaced to the west or southwest by most members. The ensemble mean 24-h rainfall accumulation over the key region of heavy rainfall is reduced by 13%, and the maximum hourly rainfall simulated by each member is reduced by 15–70 mm in CTRL relative to NURB. The reduction in the simulated rainfall by urbanization is closely associated with numerous cities/towns to the south, southeast, and east of Zhengzhou. Their heating effects jointly lead to formation of anomalous upward motions in and above the planetary boundary layer (PBL), which exaggerates the PBL drying effect due to reduced evapotranspiration and also enhances the wind stilling effect due to increased surface friction in urban areas. As a result, the lateral inflows of moisture and high-
θ
e
(equivalent potential temperature) air from south and east to Zhengzhou are reduced.
With the ulcerative colitis (UC) incidence increasing worldwide, it is of great importance to prevent and treat UC. However, efficient treatment options for UC are relatively limited. Due to the ...potentially serious adverse effects of existing drugs, there is an increasing demand for alternative candidate resources derived from natural and functional foods. Astragalin (AG) is a type of anti-inflammatory flavonoid, with
and
being its main sources. In this study, we investigated the therapeutic effects of AG on mice with dextran sulfate sodium (DSS)-induced colitis. Our results suggested that AG treatment reduced weight loss and the disease activity index (DAI), prevented colon shortening and alleviated colonic tissue damage. AG treatment reduced the expression of pro-inflammatory cytokines and related mRNAs (such as
α
, and
β), inhibited colonic infiltration by macrophages and neutrophils, ameliorated metabolic endotoxemia, and improved intestinal mucosal barrier function (increased expression levels of mRNAs such as
, and
). Western blot analysis revealed that AG downregulated the NF-κB signaling pathway. Moreover, AG treatment partially reversed the alterations in the gut microbiota in colitis mice, mainly by increasing the abundance of potentially beneficial bacteria (such as Ruminococcaceae) and decreasing the abundance of potentially harmful bacteria (such as
). Ruminococcaceae and Enterobacteriaceae (
) were thought to be the key groups affected by AG to improve UC. Therefore, AG might exert a good anti-UC effect through microbiota/LPS/TLR4/NF-kB-related pathways in mice. The results of this study reveal the anti-inflammatory effect and mechanism of AG and provide an important reference for studying the mechanisms of natural flavonoids involved in preventing inflammation-driven diseases.
Here, a single-track CoCrFeMnNi high entropy alloy（HEA） was prepared by laser melting deposition. The microstructural evolution of columnar to equiaxed transition was experimentally observed across ...the molten pool. The temperature gradient and solidification rate were theoretically calculated by a finite element model via numerical simulation. Combining experimental observations and numerical simulations, a solidification map was established to quantitatively reveal the underlying correlation between solidification parameters and microstructural morphology. A decrease in the ratio of gradient temperature to solidification rate corresponding to an increasing constitutional undercooling induced columnar to equation transition during the laser melting deposition process. It was expected that the fundamental understanding of microstructural prediction of single-track as-deposited HEA parts via the solidification map would have implications on the production of bulk components with the desired microstructure and high performance.
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•Single-track CoCrFeMnNi high entropy alloy was fabricated by laser melting deposition.•Columnar to equiaxed transition (CET) was systematically investigated combining experimental observations and numerical simulations.•A solidification map was established to quantitatively reveal the underlying correlation between temperature gradient (G) and solidification rate (R) and microstructural morphology.
For conventional active-matrix organic light-emitting diode (AMOLED) flat panel displays, low temperature poly-silicon thin-film transistor (LTPS TFT) on rigid glass substrate process has already ...been well established. However, this technology cannot be applied directly on polyimide (PI) substrate for flexible display. This is because PI has the different coefficient of thermal expansion (CTE) from the glass, which will result in PI film peeling-off and/or warpage issues under conventional LTPS-TFT process technology. In this paper, a process flow of LTPS TFT on PI substrate for flexible display application was discussed. A flexible display demo system was successfully made by optimizing the LTPS TFT process.
Purpose
The bifid mandibular canal is an anatomical variation, which causes anesthetic failure and surgical accidents occasionally. The purpose of this study is to observe the prevalence and ...anatomical location of bifid mandibular canals, providing clinical value in reducing the occurrence of surgical accidents and postoperative complications.
Methods
A total of 321 outpatients were selected in this study. Their CBCT images were observed, and the prevalence of bifid mandibular canals as well as the composition ratios of each branch type was evaluated according to the classification of Naitoh. The bifid mandibular canals and their branches’ diameter, length, horizontal distance to the buccal/lingual wall of the mandible, and vertical distance to the mandibular alveolar ridge were measured. Furthermore, 194 dry adult mandibles from the Department of Oral Anatomy and Physiology of Tianjin Medical University were observed to evaluate the prevalence and the average diameter of retromolar foramina.
Results
Of all the 321 patients, 84 (26.17%) cases of bifid mandibular canals and 105 (16.36%) sides of unilateral bifurcation were observed. Based on Naitoh’s classification, the retromolar canals were the most common types (46.67%), followed by the forward canals (40.00%), the dental canals (10.48%) and the buccolingual canals (2.86%). In 194 dry adult mandibles, 23 cases (11.86%) and 29 sides (7.47%) of retromolar foramina were found and the average diameter of retromolar foramina was 0.94 ± 0.30 mm.
Conclusion
More than a quarter of the population has the bifid mandibular canal, which is a potential factor of the onset of surgery accidents. CBCT is an effective method to identify the branches of mandibular canals. Preoperative CBCT examination can help reduce various postoperative complications.
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•A novel and simple approach is presented to uniformly distribute S-nZVI on biochar.•Phosphorus etching of biochar complexes Fe2+ before its reduction and sulfidation.•Greater ...reactive surface area of supported S-nZVI increases reactivity with FF.•Sulfur release from the particles was limited during the reaction.
Aggregation of nZVI and sulfur-modified nZVI (S-nZVI) can lower its reactivity with contaminants in water. To overcome this limitation, we synthesized biochar-supported nZVI and S-nZVI using a phosphate pretreatment of the biochar (pBC) to uniformly distribute the nZVI and S-nZVI onto the biochar support. The participation of phosphorus groups in the synthesis, and the good distribution of S-nZVI on the pBC were confirmed by FTIR, SEM, XRD, and XPS. Pretreatment of the biochar led to smaller well-dispersed S-nZVI compared to S-nZVI supported on untreated biochar. This increased the surface area of the S-nZVI and the reaction rate with the antibiotic florfenicol (FF). The removal rate of FF by pBC-S-nZVI was 4.3 times higher than that by unsupported S-nZVI. Even though FF strongly adsorbed to the pBC support, FF was fully degraded based on the mass balance results. Surface area normalized reaction rate constants (kSA) for FF removal by S-nZVI, BC-S-nZVI, and pBC-S-nZVI were similar, suggesting that the enhanced reactivity is due to the greater dispersion of S-nZVI on the treated biochar. These results provide a simple pretreatment method for dispersing nZVI or S-nZVI onto biochar supports.
During fire evacuations, crawling is recommended to prevent harm from toxic smoke and to access more breathable air. Few studies have evaluated the physiological burden of crawling, especially for ...children. The method of using wearable sensors to collect data (e.g., electrodermal activity, EDA; skin temperature, SKT) was used to evaluate the effects of different locomotive postures on children’s velocity and physiological demands. Twenty-eight (28) children (13 boys and 15 girls), aged 4 to 6 years old, traveled up to 22.0 m in different postures: Upright walking (UW), stoop walking (SW), knee and hand crawling (KHC). The results showed that: (1) Gender and age had significant impacts on children’s velocity (p < 0.05): Boys were always faster than girls in any of the three postures and the older the child, the faster the velocity for KHC. (2) Physiological results demonstrated that KHC was more physically demanding than bipedal walking, represented by higher scores of the EDA and SKT indicators, similar to the findings of adults. (3) Gender and age had significant impacts on children’s physiological demands (p < 0.05). The physiological demands were greater for boys than girls. In addition, the higher the age, the less physiological demands he/she needs. Overall, the findings suggest that children are unnecessarily required to choose crawling precisely as adults as the best posture to respond to emergency scenarios. In a severe fire, stoop walking is suggested, as there is more respired air and children could move quickly and avoid overworking physiological burdens. The results of this study are expected to be considered in the evaluation of current evacuation recommendations and for the safety guide of preparedness to improve the effectiveness of risk reduction for children.
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