•Bernstain-Bézier functions are used to develop a material model for UHSS cooled from fire.•The model considers the effect of fire temperature and sustained axial load ratio.•The model is calibrated ...and validated against experimental tests results.•The model is capable of extrapolating the results out of the range of tests data.•The creep strain of UHSS under a transient fire and a constant stress is derived.
Ultra-high strength steels (UHSS) have significant potential applications in the engineering fields due to their unique specifications. In recent years, it has been experimentally shown that the post-fire stress-strain response of this material is highly dependent on the maximum steel temperature and the sustained load applied to it during fire. This paper employs the Bernstain-Bézier functions to present the relationship between the stress, strain, the maximum fire temperature and the sustained axial load ratio (β) for Grade 1200 UHSS cooled for fire temperatures to room temperature. The experimental results are used to verify and validate the proposed model throughout the paper. The model showed to be capable of not only interpolating the stress-strain curves, but also extrapolating them out of the range of the available experimental tests data. Also, taking advantage of the stress-strain-temperature response of the UHSS tested at elevated temperatures, the instantaneous stress-induced strain and consequently the creep strain of UHSS subjected to different constant sustained load values during transient fire are obtained.
Electrocatalytic water splitting for hydrogen evolution is significantly impeded by the kinetically sluggish oxygen evolution reaction (OER). Thus, the development of highly efficient and durably ...stable non-noble-metal OER electrocatalyst is necessary and challenging for the large-scale electrocatalytic water splitting. Herein, a series of iron-substituted cobalt-nickel phosphides grown on Ni foam (FeCoNi-P/NFs) were easily prepared though successive hydrothermal and phosphorization treatments. The chemical compositions, crystalline and electronic structures as well as surface morphologies of these resulting electrocatalysts are strongly related with the iron substitution ratio. More interestingly, the FeCoNi-P/NF-2 nanosheet arrays prepared from equivalent molar ratio of iron and cobalt precursors exhibit the best OER performance with a low overpotential of 266 mV to produce a current density of 50 mA cm−2 and a low Tafel slope of 61.2 mV dec−1 in 1.0 M KOH condition, which is comparable to the reported state-of-the-art OER electrocatalysts. Additionally, the FeCoNi-P/NF-2 nanosheet arrays also show satisfactory long-term durability over 60 h. The superior OER activity of the electrocatalyst is essentially attributed to the heteroatomic substitution and the unique three-dimensional hierarchical morphology, which greatly increase the electrical conductivity, afford more active sites and facilitate the efficient charge transfer ability.
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•Fe-Co-Ni phosphide nanorods, nanowires, nanosheets and nanoflowers were synthesized.•The trimetallic phophides exhibited efficient oxygen evolution reaction activity.•The superior activity was attributed to the heteroatom and unique morphology.
Coking from pyrolytic volatiles on MFI framework is related to the deactivating carbonaceous species.
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•Improved service lifespan of zeolite related to hierarchical pores and metallic ...sites.•Aliphatics and oxygen species as coke precursors mainly deposited on external surface.•Coke-I species trend to graphitization-like with high polycondensation.•Coke deposits or the removal of coke species destroyed physical properties of zeolites.•Coke species are correlated with pyrolysis volatiles and product distribution.
HZSM-5, Co-incorporated HZSM-5 (3Co/Z5) and Co-incorporated hierarchical HZSM-5 (3Co/DZ5) were employed in catalytic reforming of volatiles from lignite pyrolysis in a drop bed reactor aiming at high yields of light aromatics. The co-effect of hierarchical pores and metallic sites on 3Co/DZ5 promoted the formation of benzene, toluene, xylene and naphthalene, and improved the service lifespan by decreasing coke formation. The influence of hierarchical pores and metallic sites on the deposition and nature of coke and on its location in the channels or/and the outer surface of zeolites was investigated. For 3Co/DZ5, the hierarchical pores retarded its deactivation by preventing internal coke formation while facilitating the external coke formation, owing to the reduced diffusion resistance of coke precursors (aromatic species) out of channels. The introduction of metallic sites brought the suppression of O-containing species depositing on zeolite. After continuous operation, the skeleton structures of both spent and regenerated catalysts were seriously damaged by coke deposition and sintering. The main causes of catalyst deactivation were assigned to two deactivating carbonaceous species with aromaticity and aliphaticity located on the inner pores and outer surface. The soluble long-chain aliphatics from coke extracts located on the outer surface were attributed to the decomposition of inherent aliphatic chain structure in lignite. The residual coke trended to graphite-like structure. The coking behavior was revealed by means of some technologies that the internal coke mainly had impact on the catalyst performance, especially for the insoluble aromatics with high polycondensation, whereas the external coke consumes the surface active sites, resulting in uninterrupted accumulation of coke precursors, eventually blocking the accessibility to channels.
The amino dicarbonylation of aryl halides affording α-ketoamides with Pd catalysts is highly dependent on the stereoelectronic properties of the involved ligands. Ionic diphosphine ligand L4 can ...serve as precursor of a hemilabile P,C (phosphine, carbene)-hybrid ligand to form a stable Pd(II)-complex, Pd-L4. In contrast, analogues L1–L3 with a similar 1-(thiophen-3-yl)-benzimidazolyl skeleton behave as typical (mono/di)phosphines. The catalytic system resulting from the complexation of PdCl2(MeCN)2 and L4 exhibits good catalytic performance in terms of aryl iodides conversion (81–95%) and α-ketoamide selectivity (80–91%), as well as the available recyclability in the RTIL of BpyBF4. The in situ FT-IR analysis reveals that the PdCl2(MeCN)2–L4 catalytic system favors the amino dicarbonylation toward α-ketoamides according to the proposed mechanism of cycle I, which involves two independent CO-insertion steps.
•Mechanical properties of various GFRP pultruded profiles under SWSSC is investigated.•Effect of initial exposure to UV radiation and moisture before subjecting to SWSSC is studied.•Samples initially ...exposed to UV and moisture show higher reductions after exposure to SWSSC.•Profiles with interlaminar shear failure are more vulnerable than profiles with bending failure.
In this research, the mechanical properties of various glass fibre reinforced polymer (GFRP) pultruded profiles exposed to seawater sea sand concrete (SWSSC) and its combination with UV radiation and water vapour condensation were studied. The effect of different conditions, duration of conditioning, and the profile cross-section configuration on the mechanical properties were investigated. Three-point bending, tension, and compression tests were carried out to obtain the mechanical properties, including flexural, tensile and compressive strengths and tensile elastic modulus. Furthermore, in order to scrutiny the mechanisms and extent of damage, scanning electron microscopy (SEM) was carried out on the test samples before and after the exposures. Finally, regression models were derived according to the experimental data to describe the mechanical properties of profiles after exposure to the aggressive environments used in this study. The maximum reductions of about 30%, 33% and 46% were observed in three-point bending, tensile and compressive tests, respectively amongst all samples when exposed for 90 days to simulated SWSSC. These reductions increased for the same sections to 52%, 47%, and 50% when the GFRP profiles were pre-exposed for 3000 h to UV radiation and moisture before exposing for 90 days to simulated SWSSC.
The design of electrode materials with specific structures is considered a promising approach for improving the performance of lithium-ion batteries (LIBs). In this paper, FeO/CoO hollow nanocages ...coated with a N-doped carbon layer (FCO@NC) was prepared using Fe-Co-based Prussian blue analogs (PBA) as a precursor. During the synthesis, dopamine was the carbon and nitrogen source. The reducing atmosphere was assured via NH
3
/Ar, which regulated the vacancies in the structure of FCO@NC as well as increased its conductivity. When used as anode materials for LIBs, the FCO@NC nanocages deliver a high reversible capacity of 774.89 mAh·g
−1
at 0.3 A·g
−1
after 200 cycles with a capacity retention rate of 80.4% and 426.76 mAh·g
−1
after 500 cycles at a high current density of 1 A·g
−1
. It is demonstrated that the hollow nanocage structure can effectively enhance the cycle stability, and the heat treatment in NH
3
/Ar atmosphere contributes to the oxygen vacancy content of the electrode materials, further facilitating its conductivity and electrochemical performance.
Graphical abstract
Helicase POLQ‐like (HELQ) is a DNA helicase essential for the maintenance of genome stability. A recent study identified two HELQ missense mutations in some cases of infertile men. However, the ...functions of HELQ in the process of germline specification are not well known and whether its function is conserved between mouse and human remains unclear. Here, we revealed that Helq knockout (Helq−/−) could significantly reduce the efficiency of mouse primordial germ cell‐like cell (PGCLC) induction. In addition, Helq−/− embryonic bodies exhibited a severe apoptotic phenotype on day 6 of mouse PGCLC induction. p53 inhibitor treatment could partially rescue the generation of mouse PGCLCs from Helq mutant mouse embryonic stem cells. Finally, the genetic ablation of HELQ could also significantly impede the induction of human PGCLCs. Collectively, our study sheds light on the involvement of HELQ in the induction of both mouse and human PGCLCs, providing new insights into the mechanisms underlying germline differentiation and the genetic studies of human fertility.
Helicase POLQ‐like (HELQ) is an essential DNA helicase for maintaining genomic stability, and its mutations have been associated with male infertility. We found that absence of HELQ markedly reduces the induction efficiency of mouse primordial germ cell‐like cells in vitro. This reduction can be partially reversed by treatment with a p53 inhibitor. Furthermore, HELQ is also implicated in the induction of human primordial germ cell‐like cells.
Long noncoding RNA KCNQ1 opposite strand/antisense transcript 1 (lncRNA KCNQ1OT1) is abnormally expressed in various solid tumors. The purpose of this study was to explore the prognostic value and ...potential functional role of lncRNA KCNQ1OT1 across cancers.
We performed a meta-analysis of published literature to evaluate the prognostic value of lncRNA KCNQ1OT1 across cancers. Verification, functional analysis, and genomic variation analysis were performed using the GEPIA, TIMER, and LnCeVar databases. According to the immune cell infiltration level, we established a prognostic model of lncRNA KCNQ1OT1 expression using public datasets of TIMER. We used quantitative real-time polymerase chain reaction (RT-qPCR) and western blot to detect the expression levels of lncRNA KCNQ1OT1 and the CD155 protein in colorectal cancer (CRC) tissues and cell lines. Then, a lncRNA KCNQ1OT1-knockdown cell line was cocultured to explore the role of lncRNA KCNQ1OT1 and CD155 in the T cell response by flow cytometric analysis.
Our results showed that the high expression of lncRNA KCNQ1OT1 was significantly related to poor overall survival across cancers, especially CRC. Interestingly, we found that COAD patients with high lncRNA KCNQ1OT1 expression and high CD8
T cell infiltration levels had a worse prognosis than those with low lncRNA KCNQ1OT1 expression and high CD8
T cell infiltration levels. Moreover, lncRNA KCNQ1OT1 and CD155 showed significantly higher expression in CRC tissue than in normal tissue, and lncRNA KCNQ1OT1 expression was positively correlated with CD155 expression in CRC. Finally, knockdown of lncRNA KCNQ1OT1 reduced CD155 expression in HCT116 and SW620 cells and enhanced the immune response in coculture with CD8
T cells.
High lncRNA KCNQ1OT1 expression is significantly correlated with poor prognosis of CRC patients and mediates the CD8
T cell response in CRC. These findings indicate that lncRNA KCNQ1OT1 is a prognostic biomarker and potential immune therapeutic target for enhancing the CD8
T cell response in CRC.
•Stability performance of innovative corrugated columns is investigated.•The corrugated columns show remarkable load-carrying capacity and ductility.•The column behaviour depends significantly on ...corrugation height and angle.•Proposed columns are cost-competitive compared to available sections in the market.
This paper focuses on the development of much-needed numerical and experimental models for understanding the mechanical behaviour, section capacity and energy absorption of the innovative fabricated columns consisting of corrugated mild-steel plates. The corrugated square columns proposed in this paper are fabricated by welding four corrugated plates which are originally produced from 3mm thick flat mild steel plates. The experiments consist of applying a compressive axial force to the columns to determine load–displacement curves of the fabricated sections. The effects of geometric parameters such as inclination angle and corrugation height are also investigated experimentally by considering three different types of corrugated columns. Moreover, a finite element model in which the effects of material and geometric nonlinearities as well as residual stresses are taken into account is developed using ABAQUS. The experimental results are also compared with those given by the finite element (FE) model whilst a good agreement is achieved. A cost analysis is also conducted in which the cost of the innovative columns proposed in this research is compared to those of conventional welded columns currently available in the civil engineering market.
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