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Ultra-high strength is obtained in the simple binary Mg-Gd alloy with only a small extrusion ratio, and its main strengthening contribution is different from that reported in previous works. The tensile yield strength (TYS) of Mg-13Gd alloy can reach 350 MPa by hot extrusion with an extrusion ratio of 4. The strong texture and internal dislocation pinning of the un-dynamically recrystallized (un-DRXed) region with large proportion contribute greatly to the strength of as-extruded alloy. It is found for the first time that aging precipitation only occurs within the large un-DRXed grains but not in the fine DRXed grains. The TYS of extruded + peak-aged alloy increases to 470 MPa. The ultra-high strength is mainly related to texture strengthening and precipitation strengthening, rather than fine grain strengthening and precipitation strengthening in the conventional Mg alloys with large plastic deformation.

The scattering of waves in the ion cyclotron range by plasma density perturbations in the edge has been previously studied by Zhang et al with the help of antenna code RAPLICASOL (2020, Nucl. Fusion, 60, 096001). The further interesting question is whether the density perturbations have an effect on ion cyclotron resonance heating (ICRH) in the core. In this paper, finite element method based 2D full wave code integrating the core with the edge is used to study this issue. The analytical density perturbations are applied to study the influence of density perturbations on field distribution, power deposition, wave coupling, power partition among different species in the core, and the fraction of energy dissipation in the scrape-off layer. The influence of density perturbations becomes global and significant when the poloidal size of the density blob is comparable to the perpendicular wavelength. In addition, the strength of wave scattering is directly proportional to the amplitude and the radial size of the density blob. Finally, a typical experiment on the EAST is chosen and the influence of realistic density perturbations on ICRH is evaluated.

The dentin collagen matrix that is not completely enveloped by resin adhesive is vulnerable to degradation by intrinsic collagenases during the etch-and-rinse process, which contributes to the deterioration of the bonding interface. Current commercial adhesives have no functional components that can form covalent bonds to the dentin collagen matrix. In this study, a photocurable aldehyde, 4-formylphenyl acrylate (FA), was synthesized and for the first time applied as a primer in adhesive dentistry to covalently bind to collagen. Experimental groups with different concentrations of FA (1%, 3%, 5%, 7%, 9%) were prepared as primers. The cytotoxicity was evaluated by live/dead-cell staining and thiazolyl blue tetrazolium bromide assay. The interaction of FA with collagen was examined by attenuated total reflection Fourier transform infrared spectroscopy, hydroxyproline release under the degradation of type I collagenase, and thermogravimetric analysis. An optimal group was selected based on the degree of conversion of 2 universal adhesives and further divided depending on the treatment time (20 s, 30 s, 1 min, 2 min). The bonding performances were evaluated by microtensile strength before and after aging. Finally, the bonding interface was observed under confocal laser scanning microscopy and scanning electron microscope. The results indicated that FA demonstrated good biocompatibility, dentin modification capability, and infiltration. It not only effectively cross-linked dentin collagen to improve its stability against enzymatic hydrolysis and modify the adhesive interface but also potentially acted as a diluting monomer to induce deep penetration of adhesive resin monomers into the dentin. The bonding strength after aging was improved without jeopardizing the degree of conversion of 2 commercial adhesives. Such prominent advantages of using FA to improve the bonding performance promotes its further application in adhesive dentistry.

Steinernema populi n. sp. was recovered by baiting from beneath poplar trees in China. Morphological and molecular features provided evidence for placing the new species into the Kushidai clade. The new species is characterized by the following morphological features: third-stage infective juveniles (IJ) with a body length of 1095 (973–1172) μm, a distance from the anterior end to excretory pore of 77 (70–86) μm and a tail length of 64 (55–72) μm. The Body length/Tail length (c) ratio and Anterior end to Excretory pore/ Tail length × 100 (E%) of S. populi n. sp. are substantially greater than those of all other ‘Feltiae–Kushidai–Monticolum’ group members. The first-generation males can be recognized by a spicule length of 66 (57–77) μm and a gubernaculum length of 46 (38–60) μm. The new species is further characterized by sequences of the internal transcribed spacer and partial 28S regions of the ribosomal DNA. Phylogenetic analyses show that Steinernema akhursti and Steinernema kushidai are the closest relatives to S. populi n. sp.

An upgrade to the magnet power digital feedback system (DFS) for the real time control of the PF coil power supplies is currently being developed and commissioned in HL-2A. The system aims to perform higher control resolution, more stable control cycle, real time monitoring and protection. The DFS has been shown to have better performance than the existing system in the control of the PF coil power supplies. It can control effectively all the PF coil power supplies, including the ohmic heating power supply (OHPS), vertical field power supply (VFPS), radial field power supply (RFPS) and the divertor coil power supply (DCPS). Meanwhile, the high-speed data transmission with reflective memory is used to transfer the control parameters of the PF coil power supplies. Moreover, the DFS also provides the real time monitor and protection based on the experimental physics and industrial control system (EPICS).

Figuring out the influencing factors is important to explore the potential of age hardening response for Mg alloys. Here the effect of different microstructure on age hardening response in extruded Mg-14Gd-2Ag-0.5Zr alloy is investigated. The age hardening response is weakened by cold-rolling for the extruded sample with large grain size due to the solute atom segregation to form bulk particles in twin boundaries during aging. Conversely, the age hardening response is enhanced by cold-rolling for the extruded sample with fine grain size and dynamical precipitates along grain boundaries, which is attributed to the segregation of solute atoms into the nano subgrain boundaries within grains during aging.

A newly-developed in situ neutron diffraction method has been employed to search elastic tension induced lattice distortions in DD10 single crystal nickel-based superalloy under tensile condition of 500 °C/760 MPa. Multiple lattice reflections, viz., {002}, {003}, {220}, {311} were in situ measured. Two samples which were stretched along [001] direction and 18° deviation of [001] direction, respectively, were measured for comparison. As samples were heated to 500 °C, the lattice stress of both samples gradually relaxes. With 760 MPa tension applied, the response of reflections of γ and γ’ phases were anisotropic. Compared with 0° sample, 18° sample resulted in distinguishable results. Due to the large extra stress, the mismatch along [001] direction is much negative, whereas that perpendicular to [001] get slightly positive. Owing to the different stress states, γ phase is divided into two conditions. The tetragonal distortion with c/a of γ⊥ channel is largest, while that of γ’ phase is small. The distortions at γ/γ’ phase boundary result in broadening the boundary of γ’ phase. In this work, a new elastic-induced lattice distortion model that enhances apprehensions to the constraint effect between γ and γ’ phases is built, which might provide the directly experimental evidence to the origin of rafting.

Ion cyclotron range of frequency (ICRF) wave heating simulation is often carried out in the core plasma region. However, the inclusion of scrape-off layer (SOL) plasma in the simulation model may lead to a new physical phenomenon and needs to be studied. In this paper, we apply a finite elements method based on the approach of Vallejos et al (2019 Nucl. Fusion 59 076022), to simulate ICRF wave heating to account realistically for SOL plasma of the EAST. In the presence of the density pedestal near the last closed flux surface, a kind of cavity mode is observed for the case of low parallel wave number. Near the ion–ion hybrid resonance (IIR) layer in the SOL region, mode conversion from fast waves to slow waves takes place. ICRF wave coupling characteristics are roughly consistent with the prediction of the dispersion relation except for some small deviations, which may be caused by fast wave reflection in the high-field side. Approximately on-axis heating of H ion is observed and the power deposition zone broadens with parallel wave number increasing. Wave energy dissipation in SOL plasma is less than 7% and localized near the IIR region. Furthermore, the comparison between D(H) and D(He-3) minority heating scenarios is also carried out. The results and conclusions in this paper can provide a theoretical reference for ICRF heating experiments and may supply a new insight into the form of ICRF waves in the plasma edge.

Since the last IAEA Fusion Energy Conference in 2018, significant progress of the experimental program of HL-2A has been achieved on developing advanced plasma physics, edge localized mode (ELM) control physics and technology. Optimization of plasma confinement has been performed. In particular, high-β N H-mode plasmas exhibiting an internal transport barrier have been obtained (normalized plasma pressure β N reached up to 3). Injection of impurity improved the plasma confinement. ELM control using resonance magnetic perturbation or impurity injection has been achieved in a wide parameter regime, including types I and III. In addition, impurity seeding with supersonic molecular beam injection or laser blow-off techniques has been successfully applied to actively control the plasma confinement and instabilities, as well as plasma disruption with the aid of disruption prediction. Disruption prediction algorithms based on deep learning are developed. A prediction accuracy of 96.8% can be reached by assembling a convolutional neural network. Furthermore, transport resulting from a wide variety of phenomena such as energetic particles and magnetic islands has been investigated. In parallel with the HL-2A experiments, the HL-2M mega-ampere class tokamak was commissioned in 2020 with its first plasma. Key features and capabilities of HL-2M are briefly presented.

This study investigated the effects of dietary Arginine (Arg) on performance, intestinal antioxidative capacity, immunity, and gut microbiota in Chinese yellow-feathered chickens. One thousand two hundred 1-day-old female Qingyuan partridge chickens were randomly assigned to 5 groups with 6 replicates of 40 birds each. Chickens were fed diets with 5 levels of total Arg (8.5, 9.7, 10.9, 12.1, and 13.3 g/kg) without antibiotics for 30 d. The ADFI, ADG, and feed conversion ratio were improved with dietary Arg levels (P < 0.05). The proportions of CD3+ and CD4+/CD8+ lymphocytes responded in a linear (P < 0.05) manner and those of CD4+ in a linear or quadratic (P < 0.05) manner as dietary Arg levels increased. Dietary Arg level had a linear (P < 0.05) or quadratic (P < 0.05) effect on the gene expression of glutathione peroxidase 1, heme oxygenase 1, nuclear factor erythroid 2-related factor 2, and the activities of glutathione peroxidase and total antioxidative capacity in the jejunum and ileum. The relative expression of IL-1β, myeloid differentiation primary response 88, and Toll-like receptor 4 decreased linearly (P < 0.05) in the ileum with increasing dietary Arg levels; secretory IgA contents were increased. In addition, sequencing data of 16S rRNA indicated that dietary Arg increased the relative abundance of Firmicutes phylum, Romboutsia and Candidatus Arthromitus genera, while decreased that of Clostridium sensu stricto 1. A diet containing 12.1 g Arg/kg promoted growth performance, intestinal antioxidation, and innate immunity and modulated gut microbiota in yellow-feathered chickens.

This study reports the formation mechanism of inhomogeneous microstructure in AZ31 Mg alloy extruded by porthole die. Two streamlines corresponding to welding and matrix zones of the extruded profile were focused, and the evolution of microstructure and texture was investigated. The results show that (i) Welding zone streamline: The complete dynamic recrystallization (DRX) occurred after splitting stage, and the microstructure consists of equiaxed grains with several microns. Strong shearing texture is formed during splitting stage, and the c-axis has a deviation with normal direction. Then, the basal plane rotates to be perpendicular with normal direction during the welding stage. The main textures are identified as //ND and {0001} textures, while the fraction of these two components varies significantly during extrusion process. (ii) Matrix zone streamline: The coarse elongated grains were reserved along the whole streamline, which indicates the occurrence of partial DRX. Moreover, the {10–12} extension twins appear inside the coarse unDRXed grains. The basal plane of unDRXed grains tends to be perpendicular to ED direction with a deviation angle, and the {11–20} texture can also be observed. However, the orientation concentration with certain pattern was not formed for DRXed grains.

Considering the side effects of etomidate, it requires additional anesthetics to reduce the side effects and improve efficacy. Ketamine is often used as an adjunct anesthetic. We hypothesized that etomidate combined with fentanyl was more effective than etomidate combined with ketamine in the anesthesia of pediatric strabotomy. To prove our hypothesis, a prospective randomized controlled clinical study was performed, in which 35 children with strabotomy received etomidate plus ketamine (group A) for anesthesia induction and maintenance and 35 children with strabotomy received etomidate combined with fentanyl (group B). Mean arterial pressure (MAP), heart rate (HR), bispectral index (BIS), anesthesia effect, and emergence agitation and pain were observed before anesthesia induction (T1), after anesthesia induction (T2), at the beginning of the operation (T3), after 10-min operation (T4), and at the end of the operation (T5). Children in group B had significantly lower MAP and HR from T3 to T5, decreased BIS from T2 to T4, better anesthesia effect, and smaller emergence agitation and pain scores at 10 min after entering into postanesthesia care unit (PACU) compared with group A (p 0.05). The mean emergence agitation score in group B was significantly lower than that in group A when the maximum emergence in group B was at 20 min after entering into PACU (p 0.05). In conclusion, etomidate combined with fentanyl plays a good efficacy in anesthesia of pediatric strabotomy compared with etomidate plus ketamine.

A self-developed triaxial test method was adopted to characterize mechanical behavior of the asphalt mixture under three-dimensional stress states in this study. The conventional uniaxial tests and triaxial tests were conducted in the laboratory to verify the triaxial test results obtained using the technique developed. It is shown that the three dimensional stress states affect significantly the ultimate failure strength of AC-13 asphalt mixture and the failure modes are mainly represented both for the tensile failure and shear failure. The nonlinear strength criterions, as well as a linear engineering model of asphalt mixture under three-dimensional stress states in σ oct - τ oct space, were established based on the triaxial compressive/tensile tests, the plane tensile and compressive/axial tensile tests. In addition, a new method to carry out the strength design of asphalt pavement under the three-dimensional stress state was given to consider the failure effect of each stress component to the asphalt pavements.

Porthole die extrusion of Mg-Al-Zn alloy was conducted using the as-cast, as-homogenized and as-extruded billets. The effects of initial microstructure on grain size, secondary particle, texture and mechanical properties of the extruded profiles were investigated. The results showed that complete dynamic recrystallization (DRX) occurred in welding zone of all profiles, and the profile extruded from as-cast billet had the smallest DRXed grains. Large un-DRXed grains with {10−12} extension twins were found in the matrix zone of the profiles extruded from as-cast and as-homogenized billets. In welding zone, all profiles have a strong basal plane texture with directions parallel to transverse direction, while the texture intensity and distribution significantly varied with initial billets. The profile obtained from as-extruded billet exhibited inferior tensile properties due to its low solid bonding degree. The hardness distribution in matrix zone of the profiles was not uniform due to the inhomogeneous microstructure.

Nanocrystalline metals, e.g., Mg, are often strong but with a low thermal stability. In this study, six solute elements, Ti, Zr, Ta, Co, Cr, La, which are immiscible in Mg under equilibrium conditions, are mechanically alloyed with Mg to study the extension of solid solubility, the thermal stability and the mechanical properties of nanocrystalline Mg. Extended solid solubility of Ti and Zr solutes in Mg matrix is achieved after mechanical alloying. The nanocrystalline Mg is largely stabilized by Ti, moderately stabilized by Zr, and not stabilized by Ta, Co, Cr and La. The onset temperature for a rapid grain growth increases from 100 °C (0.4 Tm) for nanocrystalline Mg to ~ 350 °C (0.68 Tm) for nanocrystalline Mg0.95Ti0.05 (defined as Mg-5Ti). A relatively small grain size of ~ 145 nm is achieved in Mg-5Ti at 350 °C. The enhanced thermal stability of nanocrystalline Mg-Ti alloy can be attributed to the segregation of Ti atoms at grain boundaries. In addition, an abnormal grain growth is also observed because of the inhomogeneous distribution of solute/impurity atoms. The high thermal stability of nanocrystalline Mg-5Ti alloy enables us to degass the mechanically alloyed powders at a high temperature of 300 °C and achieve a porosity-free nanocrystalline bulk with a compressive yield strength of 183 MPa and a fracture strain of above 0.6.

A TiCnp /Mg–2Zn-0.8Sr-0.2Ca magnesium matrix composite was processed by the combination of multidirectional forging (MDF) with extrusion (EX). The composite exhibited ultrahigh mechanical properties (yield strength of ~500 MPa and ultimate tensile strength of ~544 MPa) after 6 passes of MDF at 300 °C, followed by EX at 0.1 mm/s and 200 °C. The grain boundary strengthening effect caused by grain refinement and high recrystallization rate, dislocation strengthening effect originated from the severe plastic deformation , as well as the Orowan strengthening effect inspired by the dynamically precipitated MgZn 2 phases and the added TiCnp were considered as the main contributors to the substantial increase in strength.

Ideal structural materials should have both high strength and good ductility. Aging treatment is an effective way to increase the strength of Mg alloys, but usually sacrifices their ductility. Here we have successfully achieved the synergetic enhancement of strength and ductility of the extruded Mg-13Gd alloy via aging treatment, and obtained a Mg alloy with a tensile yield strength of 400 MPa and an elongation of 15%. The synergetic improvement of strength and ductility is mainly attributed to the formation of high-density nanoscale β′ precipitates and a certain proportion of precipitation free zone in the microstructure dominated by dynamically recrystallized fine grains. The yield drop phenomenon in the tensile curves is sensitive to the existence of movable pinned-dislocations within grains. It is expected that the discussion in this study will be helpful to developing Mg alloys with high strength and ductility via aging treatment.

This study investigated the effects of aging and thermomechanical treatments on the microstructure evolution and mechanical properties of a nanoprecipitates strengthened ferritic steel. The toughness of steel at various temperatures was measured carefully and correlated with microstructural features. Tensile tests show that aging can improve the mechanical strength without scarifying the ductility. With high yield strength of ~1000 MPa, excellent low temperature Charpy impact energy more than 300 J at −80 °C can be obtained. The ductile brittle transition temperature (DBTT) is lower than −80 °C. The high strength can be contributed by the nanocluster precipitation as determined by small angle neutron scattering and transmission electron microscopy. The excellent low temperature toughness is attributed to the delamination structure of the steel, which blunts the cracks and restrains the crack propagation.

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical science. © The Author(s) 2019. Published by Oxford University Press.

Screen covering is a widely used soil conservation practice to control water erosion in coarse-textured soil areas. A better understanding of the effects of screen covers at reducing rainfall kinetic energy (KE) on the erosion behavior will improve erosion prediction and control measures development. The objective of this study was to investigate and quantify the effects of rainfall KE on the soil loss and sediment sorting for developing a prediction model in a coarse-textured soil. A series of rainfall simulation experiments were conducted in three horizons of a coarse-textured soil under five rainfall KEs (628, 443, 324, 231, and 110 J m−2 h-1) which were obtained by covering the soil surface with wire screens of different apertures at a coincident intensity of 90 mm h-1. The results showed that the increase in rainfall KE increased runoff rate and soil erosion rate. The soil erosion rate also increased with depth of the soil layer exposed to the soil surface. Based on the soil clay content, a power relationship could describe the relationships between soil erosion rate and geometric mean diameter of sediment and stream power. With increasing rainfall KE and runoff duration, although the percentage of clay- and silt-sized particles in the sediment decreased, both were still higher than the content in the original soil. The enrichment of fine particles in runoff produced a coarsening layer on the slope surface, which might restrain the subsequent erosion in situ. The observed large preferential loss of clay- and silt-sized particles by erosion emphasizes the importance of sediment sorting for subsequent erosion in these coarse-textured soils. These results suggest that the relationship of rainfall KE to erosion should be considered for practical and effective estimation and prediction of the potential erosiveness of rainstorms.

Temperature-dependence surface relief during cubic↔tetragonal martensitic transformation (MT) in Mn69.4Fe26.0Cu4.6 antiferromegnetic shape memory alloy was studied by means of in-situ atomic force microscopy. The surface morphology memory effect was found and the crystallography reversibility of the transformation and its shearing characters were directly verified. Twin shearing is suggested as the main mechanism of formation of tent-type surface relief. The surface relief angle (θα|θβ)

A new phenomenon of tensile yielding plateau in the fine-grained age-type Mg-14Gd-2Ag-0.5Zr alloy is reported, which is closely related to the activation of mobile pinned-dislocations. The yielding plateau contributes ~6% strain in the peak-aged sample, while it contributes only ~2% strain in the extruded sample.

The as-extruded AZ91D magnesium alloy processed by conventional extrusion exhibits a yield strength of 320 MPa, an ultimate tensile strength of 382 MPa and a fracture elongation of 13.8%, superior than most AZ91D alloys reported so far, which is mainly attributed to ultra-fine grains, sub-micron precipitates, and strong texture.