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The Ti-4Al-0.005B alloy were rolled at 940 °C or 990 °C followed by annealing at 650 °C. In order to control the final microstructure, rolling at medium temperature of 550 °C was processed in two other plates after rolling at 940 °C or 990 °C. The rolling and tensile behaviors of Ti-4Al-0.005B alloy with equiaxed and lamellar microstructure are comparatively studied using electron backscatter diffraction (EBSD) technique. It is found that the grain refinement mechanism of 940 °C and 940 + 550 °C rolled samples is continuous dynamic recrystallization (CDRX), while the 990 + 550 °C samples combine CDRX and twinning. The strong basal/near basal textures (B/N textures) in 940 °C and 940 + 550 °C rolled samples was mainly related to basal slip and pyramidal slip. Strong transverse textures (T-type texture) formed in 990 °C rolled sample due to variant selection during the β→α phase transformation and 990 + 550 °C rolled sample exhibits a mixed of T-type texture and B/N texture. The 990 + 550 °C rolled sample exhibited a best mechanical properties combined of strength and ductility due to its mixed texture and refined α grains.

This study experimentally investigated the electrochemical corrosion and pitting corrosion of Ti–6Al–4 V alloy samples with different roughness in 12 wt.% HCl solution at 35 °C. The corrosion behavior of these alloy samples was studied by potentiostatic and potentiodynamic polarization. Both the corrosion rate and pitting sensitivity of the sample increased with increasing surface roughness. Moreover, the effect of surface roughness on the corrosion of Ti–6Al–4 V alloy could be characterized by the aspect ratio (w/d) of the peak–valley morphology on the surface, where w and d are the width of the valley and relative depth of the peak. The w/d and true surface areas influenced the pitting corrosion of the alloy. Polishing the surface of the Ti–6Al–4 V alloy can enhance the corrosion resistance of the working surface, rendering the material suitable for use in the oil and gas industries. Keywords: Ti–6Al–4V alloy, Surface roughness, Polarization, Electrochemical impedance spectroscopy, Pitting corrosion

Copper nanoparticle (Cu NP) is a promising replacement for noble metal nanoparticles due to its high electrical conductivity and low cost. However, Cu NPs are relatively active compared to noble metals, and current ways of protecting Cu NPs from oxidation by encapsulation have severe drawbacks, such as a long reaction time and complicated processes. Here, a facial and effective method to prepare the mesosphere of carbon-shelled copper nanoparticles (Cu@MC) was demonstrated, and the resulting Cu@MC was both highly electrically conductive and thermally stable. Cu@organic (100 nm) was first synthesized by the reduction of Cu ions with poly (vinyl pyrrolidone) (PVP) and sodium poly ((naphthalene-formaldehyde) sulfonate) (Na-PNFS) as soft templates. Then, the carbon shells were obtained by in situ carbonization of the polymer soft templates. The Cu@organic and Cu@MC showed an anti-oxidation ability up to 175 and 250 °C in the air atmosphere, respectively. Furthermore, the Cu@MC exhibited excellent volume resistivity of 7.2 × 10−3 Ω·cm under 20 MPa, and showed promising application potential in electric sensors and devices.

High-temperature compression deformation of a Zr-4 metal matrix with dispersed coated surrogate nuclear fuel particles was investigated at 750 °C–950 °C with a strain rate of 0.01–1.0 s−1 and height reduction of 20%. Scanning electron microscopy was utilized to investigate the influence of the deformation conditions on the microstructure of the composite and damage to the coated surrogate fuel particles. The results indicated that the flow stress of the composite increased with increasing strain rate and decreasing temperature. The true stress–strain curves showed obvious serrated oscillation characteristics. There were stable deformation ranges at the initial deformation stage with low true strain at strain rate 0.01 s−1 for all measured temperatures. Additionally, the coating on the surface of the surrogate nuclear fuel particles was damaged when the Zr-4 matrix was deformed at conditions of high strain rate and low temperature. The deformation stability was obtained from the processing maps and microstructural characterization. The high-temperature deformation activation energy was 354.22, 407.68, and 433.81 kJ/mol at true strains of 0.02, 0.08, and 0.15, respectively. The optimum deformation parameters for the composite were 900–950 °C and 0.01 s−1. These results are expected to provide guidance for subsequent determination of possible hot working processes for this composite. Keywords: Zr-4 metal matrix, Coated surrogate nuclear fuel particles, High-temperature deformation, Processing map, Microstructure

The plastic deformation processes and fracture behavior of a Ti–5Al–5Mo–5V–1Cr–1Fe alloy with bimodal and lamellar microstructures were studied by room-temperature tensile tests with in situ scanning electron microscopy (SEM) observations. The results indicate that a bimodal microstructure has a lower strength but higher ductility than a lamellar microstructure. For the bimodal microstructure, parallel, deep slip bands (SBs) are first noticed in the primary α (αp) phase lying at an angle of about 45° to the direction of the applied tension, while they are first observed in the coarse lath α (αL) phase or its interface at grain boundaries (GBs) for the lamellar microstructure. The β matrix undergoes larger plastic deformation than the αL phase in the bimodal microstructure before fracture. Microcracks are prone to nucleate at the αp/β interface and interconnect, finally causing the fracture of the bimodal microstructure. The plastic deformation is mainly restricted to within the coarse αL phase at GBs, which promotes the formation of microcracks and the intergranular fracture of the lamellar microstructure.

Texture evolution of as-annealed hot rolled Al-Cu-Mg sheets with initial R-Cube {001}〈110〉, R-Cu {112} 〈110〉, and m-Brass {211}〈0,−1,1〉 texture has been studied by X-ray diffraction. Continuous overall texture intensity weakening effect and micro-mechanism, during the isochronal annealing at 280–480 °C for 2 h, was investigated using electron backscatter diffraction and scanning electron micrograph. A new texture fibre {φ1 = 0° − 90°, φ = 65°, φ2 = 63°} has been found. The results show that obvious overall texture intensity weakening started at 400 °C. The texture intensity ratio can be used to depict such weakening trend. Moreover, the overall texture intensity was determined by the reduction of R-Cube at 400–420 °C, but related to the decomposition of Brass at 420–480 °C. Such decomposition of Brass and induced rebound of orientations on the m-fibre, as well as R-Cu texture, due to the near 30°〈111〉 relationship, led to the further overall texture weakening and severe randomization. Keywords: Aluminium alloy, R-Cube, M-fibre, Texture intensity ratio

Theprecipitate behavior, mechanical properties and corrosion behavior of an Al-Zn-Mg-Cu alloy during non-isothermal creep aging were investigated. The results show that diffraction patterns of GPI zones gradually disappear and those of η′ phases are strengthened during the heating stage. More importantly, the size and volume fraction of precipitates increase with aging temperature increasing, which greatly enhances the mechanical properties of the alloy. The hardness and tensile strength of the alloy with H210 aging condition are 165 HV and 564 MPa, respectively. During the cooling stage, in addition to the diffraction pattern of η′ phase, that of GPI zones can be observed again. Furthermore, the size of the precipitates decreases, and the volume fraction reaches a maximum. The hardness and tensile strength of the alloy with C120 aging condition reach 185 HV and 580 MPa, respectively. Furthermore, the characteristics of the grain boundary reveal that the width of precipitation free zones (PFZ) first increases during the heating stage and then decreases during the cooling stage. In the C120 condition, the newly generated secondary precipitates and the coarsening of undissolved precipitates around the grain boundary lead to the further narrowing of PFZ, but the coarse grain boundary precipitates (GBPs) are still not continuously distributed in the grain boundary. Hence, the alloy with C120 condition exhibits the most excellent corrosion resistance.

Al–Cu, being a high-strength aluminium alloy, is used to prepared castings which are widely used in the automotive and aerospace industries as lightweight parts. However, corrosion is an issue. The Al–Cu alloys show improved properties when other elements are added to them. One such alloy is Al–4.5Cu–3.5Zn–0.5Mg. In order to improve the corrosion resistance and strength of this Al–4.5Cu–3.5Zn–0.5Mg cast alloy, a novel non-isothermal ageing (NIA) treatment was developed that comprised a heating stage up to 250 °C, followed by a cooling stage down to room temperature at the rate of 60 °C·h ^−1 . Specimens were removed throughout the process and immediately quenched for morphological, mechanical, and electrochemical testing. The hardness continuously increased up to 124 HV with ageing time. The alloy exhibited optimal properties after ageing for ~340 min (with the aging temperature reaching 130 °C during the cooling stage of the NIA treatment), with a tensile strength and maximum corrosion depth of 395 MPa and 165 μ m, respectively. Fine precipitates discontinuously appeared at the grain boundaries during the cooling stage. Some new fine Ω phases were precipitated in the grains, thereby narrowing the precipitation-free zone. Thus, high strength and good corrosion resistance of the alloy can be obtained via the NIA treatment. Notably, NIA treatments are less time-consuming than isothermal ageing treatments, thereby expanding the applications of high-strength cast aluminium alloys in the manufacturing industry.

Thermophotovoltaic (TPV) systems can convert radiant energy into electrical power. Here we explore the design of the TPV system cavity, which houses the emitter and the photovoltaic (PV) cells. Mirrors are utilized in the cavity to modify the spatial and spectral distribution within. After discussing the basic concentric tubular design, two novel cavity configurations are put forward and parametrically studied. The investigated variables include the shape, number, and placement of the mirrors. The optimization objectives are the optimized efficiency and the extended range of application of the TPV system. Through numerical simulations, the relationship between the design parameters and the objectives are revealed. The results show that careful design of the cavity configuration can markedly enhance the performance of the TPV system.

The restoration of large support rollers poses an industrial challenge due to the high energy consumption of traditional repair methods. Consequently, a novel approach for repairing support rollers has been introduced and tested on thick-walled components. Finite element simulations aided the study of welding repairs for large thick-walled components, examining element distribution, microstructure, mechanical properties, and residual stress distribution across various processes. The results indicate that employing ABAQUS2023 finite element software to analyze stress variations under different working conditions, the Dynamically Controlled Low-Stress No-Distortion method effectively mitigates residual stresses both during and post welding, reducing average transverse residual stresses by 14.5% and average longitudinal residual stresses in the weld zone by 29.1%. The Dynamically Controlled Low-Stress No-Distortion method narrows the high-temperature range of the heat source, consequently decreasing the size of the heat-affected zone by 33.3% compared to conventional welding. The microstructure featured dendrites and equiaxed columnar crystals, with the Dynamically Controlled Low-Stress No-Distortion method capable of grain refinement, transforming some equiaxed columnar crystals into cellular structures. As grains were refined, microhardness improved, with the covering layer’s microhardness rising by 14.68%. A comparison between simulated and measured values of lateral and longitudinal residual stresses at corresponding points revealed discrepancies of 14.6% and 20.5% in accuracy, respectively.

Summary: Understanding the emergence of human notochordal cells (NC) is essential for the development of regenerative approaches. We present a comprehensive investigation into the specification and generation of bona fide NC using a straightforward pluripotent stem cell (PSC)-based system benchmarked with human fetal notochord. By integrating in vitro and in vivo transcriptomic data at single-cell resolution, we establish an extended molecular signature and overcome the limitations associated with studying human notochordal lineage at early developmental stages. We show that TGF-β inhibition enhances the yield and homogeneity of notochordal lineage commitment in vitro. Furthermore, this study characterizes regulators of cell-fate decision and matrisome enriched in the notochordal niche. Importantly, we identify specific cell-surface markers opening avenues for differentiation refinement, NC purification, and functional studies. Altogether, this study provides a human notochord transcriptomic reference that will serve as a resource for notochord identification in human systems, diseased-tissues modeling, and facilitating future biomedical research.

The Johnson–Cook model is widely used because of its ability to meet the simulation material requirements in various situations. However, under different working conditions, the accuracy of the model may have errors. In this work, based on Abaqus (Abaqus R2022 Education Edition, Dassault Systèmes, Paris, France) simulation software, Johnson–Cook (JC) constitutive model parameters and compression parameters were selected to simulate the improvement of surface roughness during the ball milling of a 7075-T651 aluminum alloy. In the numerical simulation of ball polishing, the changes in the residual stress field when the Johnson–Cook parameters change are analyzed. By comparing the numerically simulated residual stress fields under the JC parameters calculated at different strain rates, a set of parameters that agrees with the experimental values is selected. The results show that the residual stresses are in line with the experimental values when the strain rate is 10−4s −1. The changes in roughness corresponding to the selected parameters are analyzed. The results indicate that the simulated trend of roughness variation is consistent with the experimental values, and the optimal surface roughness value under a static pressure of 300 N is obtained.

Pelteobagrus vachelli is a freshwater fish with high economic value, but the lack of genome resources has severely restricted its industrial development and population conservation. Here, we constructed the first chromosome-level genome assembly of P. vachelli with a total length of approximately 662.13 Mb and a contig N50 was 14.02 Mb, and scaffolds covering 99.79% of the assembly were anchored to 26 chromosomes. Combining the comparative genome results and transcriptome data under environmental stress (high temperature, hypoxia and Edwardsiella. ictaluri infection), the MAPK signaling pathway, PI3K-Akt signaling pathway and apelin signaling pathway play an important role in environmental adaptation of P. vachelli, and these pathways were interconnected by the ErbB family and involved in cell proliferation, differentiation and apoptosis. Population evolution analysis showed that artificial interventions have affected wild populations of P. vachelli. This study provides a useful genomic information for the genetic breeding of P. vachelli, as well as references for further studies on fish biology and evolution.

This study focuses on the synthesis of TiC-TiB2/Fe coatings with varying amounts of aluminum (Al) using tungsten inert gas (TIG) cladding and investigates the impact of Al addition on microstructure refinement and performance enhancement of the coatings. The coatings were prepared on a mild steel substrate using TIG cladding. X-ray diffraction (XRD) analysis revealed the presence of TiC, TiB2, AlxTi, and AlxFe phases in the coatings. Scanning electron microscopy (SEM) images showed that the addition of Al improved the microstructure, reducing defects and enhancing the distribution of reinforcing phases within the coatings. The particle size of the reinforcing phases was significantly refined by the addition of Al. The micro-hardness of the coatings was significantly higher than that of the substrate, with the maximum micro-hardness of the coating reaching 955.5 ± 50.7 HV0.1, approximately six times that of the substrates. However, excessive Al addition led to a reduction in hardness due to a decrease in the quantity of hard phases. The wear tests showed that all the coatings had lower wear loss compared to the substrate material, with the wear loss initially decreasing and then increasing with the increasing Al content. Samples with a 28.57 wt.% Al addition exhibited the best wear resistance, with approximately 16.8% of the wear volume loss compared to mild steel under the same testing conditions, attributed to the optimal combination of reinforcement phase quantity and matrix properties.

CoCrxFeMnNi (x represents the atomic percentage of Cr element, x = 20, 25, 30, and 35, denoted as Cr20, Cr25, Cr30, and Cr35 alloys) high-entropy alloy (HEA) coatings were cladded by plasma arc on the surface of 0Cr13Ni5Mo steel. The effects of Cr elements on the cavitation erosion mechanisms were studied by comparing the differences of microstructure, microhardness, cavitation erosion volume loss (CVL), cavitation erosion volume loss rate (CER), and eroded surface morphologies between the coatings. As the Cr content increased, the microhardness of the coatings increased continuously, and the microstructure transformed into fine dendrites. The microhardnesses of Cr20, Cr25, Cr30, and Cr35 were 223.9 HV, 250.5 HV, 265.2 HV, and 333.7 HV, respectively. With structural change, the slip pattern shifted from uniform distribution to distribution along the grain boundary, increasing slip resistance. Additionally, strain hardening capacity increased with reduced stacking fault energy (SFE). The resistance to cavitation erosion (CR) of the HEA increased with the increase in Cr content. The CVL of 20 h cavitation erosion of Cr35 coating was only 26.84% of that of 0Cr13Ni5Mo steel, and the peak CER was only 28.75% of that of 0Cr13Ni5Mo steel. The fracture damage mechanisms of the four HEA coatings were an obvious lamellar structure and fibrous fracture.

In the process of Cr8 roller production, the phenomenon of coarse grain size and uneven grain size often appears, which makes the mechanical properties of the material decrease sharply. Accurate dynamic recrystallization model is the basis for predicting the change of grain size during thermal processing, and is an important basis for refining grain and improving material properties. In this study, the isothermal compression experiment was carried out on Cr8 alloy steel at 900–1200 °C and 0.005–0.1 s−1 by Gleeble –1500D thermal simulation compressor, and the stress dates of Cr8 alloy steel were obtained. According to experimental data, the Kopp dynamic recrystallization model of Cr8 alloy steel was established. The dynamic recrystallization volume fraction obtained by Kopp model was compared with that obtained by experiment at the same temperature and strain rate. The correlation value was 0.988, and the root mean square error (RMSE) was 0.053, which proved that the DRX model established was reliable. Through the secondary development of the program, the DRX model of Cr8 alloy steel was written into the software Forge® to verify the microstructure evolution model. The compression process of a cylindrical specimen of Cr8 alloy steel at 0.1 s−1 and 1050 °C was simulated, and the DRX microstructure evolution of the alloy was calculated. The comparison between the final grain size calculation results and the test metallographic photos of samples in different deformation zones shows the relative error of the grain size was less than 10.6%, indicating that the DRX model of Cr8 alloy steel can better predict the dynamic recrystallization of Cr8 alloy steel.

Purpose: This article intended to introduce the recent Chinese compulsory education quality assessment. Design/Approach/Methods: The article summarized education policy documents relevant to the recent Chinese compulsory education quality assessment, especially from the three reports: The Chinese Compulsory Education Quality Monitoring Report , The Chinese Compulsory Education Quality Monitoring Report on Mathematical Learning , and The Chinese Compulsory Education Quality Monitoring Report on Physical Education and Health. Findings: The article examined the development of Chinese education quality assessment in the context of the nation’s pursuit of holistic education. It first reviewed a brief history of the education quality monitoring work in China that bore the fruits of a few recent reports. Second, findings and the framework of the assessment are demonstrated. Finally, I discuss the significance, limitations, and special issues of the assessment. Originality/Value: The article is among the earliest to present findings of the recent quality assessment in Chinese compulsory education in English critically.

Reduced representation bisulfite sequencing (RRBS) provides an efficient method for measuring DNA methylation at single base resolution in regions of high CpG density. This technique has been extensively tested on the HiSeq2500, which uses a 4-colour detection method, however it is unclear if the method will also work on the NextSeq500 platform, which employs a 2-colour detection system. We created an RRBS library and sequenced it on both the HiSeq2500 and NextSeq500, and found no significant difference in the base composition of reads derived from either machine. Moreover, the methylation calls made from the data of each instrument were highly concordant, with methylation patterns across the genome appearing as expected. Therefore, RRBS can be sequenced on the Nextseq500 with comparable quality to that of the HiSeq2500. All sequencing data are deposited in the GEO database under accession number GSE87097.

Purpose: In line with a recent call for side effects research in education, this article aims to synthesize the major concerns that have been raised in the literature concerning large-scale assessments (LSAs) in education. Design/Approach/Methods: The researchers endeavored to complete a deep review of the literature on LSAs to synthesize the reported side effects. The review was synthesized thematically to understand and report the consequences of the ongoing push for the use of LSA in education. Findings: Thematic analysis indicated overarching side effects of LSA in education. We discuss why negative side effects exist and present evidence of the most commonly observed side effects of LSA in education, including distorting education, exacerbating inequity and injustice, demoralization of professionals, ethical corruption, and stifling of innovation in education. Originality/Value: While concerns about the use and misuse of LSA in education are not new and have been discussed widely in the literature, rarely have they been discussed as inherent qualities and consequences of LSAs that can do harm to education.

Cavitation corrosion resistant coatings are an excellent solution to the cavitation corrosion problem. High entropy alloys provide a new possibility for cavitation resistant coatings due to their excellent comprehensive performance. Laser cladding was employed to synthesize AlCoCrxCuFe (x represents the Cr concentration, x = 0.5, 1.0, 1.5, 2.0) high entropy alloy coatings (HECs) on AISI 304 steel. The phase transformation, microstructure, micro-mechanical properties, and cavitation erosion performance of HECs were studied. Results showed that AlCoCrxCuFe HECs were composed of BCC and FCC duplex phase. The microstructure of HECs showed a typical dendritic structure. The composition segregation of interdendrite structures was observed. Cavitation erosion resistance represented by 20 h volume loss was decreased with the increase in Cr content. AlCoCrxCuFe HECs with the lowest chromium content (AlCoCr0.5CuFe) showed the best cavitation erosion resistance among all samples. The cavitation resistance of AlCoCrxCuFe HECs has good correlation with the mechanical parameter Hn3/Er2 (Hn is nanohardness, Er is elastic modulus) and phase formation parameter δ (δ is atomic radius difference). The surface after 20 h of cavitation erosion testing exposed the dendritic structure of BCC phase, which was caused by the destruction of the interdendrite structure by cavitation impact.

MicroRNAs (miRNAs) are a class of endogenous small non-coding RNAs that regulate gene expression by post-transcriptional repression of mRNAs. Recently, several miRNAs have been confirmed to execute directly or indirectly osmoregulatory functions in fish via translational control. In order to clarify whether miRNAs play relevant roles in the osmoregulation of Anguilla marmorata, three sRNA libraries of A. marmorata during adjusting to three various salinities were sequenced by Illumina sRNA deep sequencing methods. Totally 11,339,168, 11,958,406 and 12,568,964 clear reads were obtained from 3 different libraries, respectively. Meanwhile, 34 conserved miRNAs and 613 novel miRNAs were identified using the sequence data. MiR-10b-5p, miR-181a, miR-26a-5p, miR-30d and miR-99a-5p were dominantly expressed in eels at three salinities. Totally 29 mature miRNAs were significantly up-regulated, while 72 mature miRNAs were significantly down-regulated in brackish water (10‰ salinity) compared with fresh water (0‰ salinity); 24 mature miRNAs were significantly up-regulated, while 54 mature miRNAs were significantly down-regulated in sea water (25‰ salinity) compared with fresh water. Similarly, 24 mature miRNAs were significantly up-regulated, while 45 mature miRNAs were significantly down-regulated in sea water compared with brackish water. The expression patterns of 12 dominantly expressed miRNAs were analyzed at different time points when the eels transferred from fresh water to brackish water or to sea water. These miRNAs showed differential expression patterns in eels at distinct salinities. Interestingly, miR-122, miR-140-3p and miR-10b-5p demonstrated osmoregulatory effects in certain salinities. In addition, the identification and characterization of differentially expressed miRNAs at different salinities can clarify the osmoregulatory roles of miRNAs, which will shed lights for future studies on osmoregulation in fish.