The stacking fault energy (SFE) values of several typical face-centered-cubic (fcc) high-entropy alloys (HEAs) were experimentally measured by weak-beam dark-field transmission electron microscopy. ...It was found that the SFE of the Fe-Co-Ni-Cr-Mn HEA system strongly depends on the SFE of the individual constituents. Specifically, the SFE of this HEA system is closely associated with the Ni concentration in the alloys. Additionally, the lower SFE tends to promote formation of more deformation twins with a smaller thickness under loading, leading to better mechanical properties, especially at low temperatures.
•SFE of six Fe-Co-Ni-Cr-Mn HEAs was measured experimentally.•Constituents play an important role in the SFE, particularly the Ni content.•Lower SFE promotes formation of thinner twins during loading and better properties.
Preoperative evaluation of the number of lymph node metastasis (LNM) is the basis of individual treatment of locally advanced gastric cancer (LAGC). However, the routinely used preoperative ...determination method is not accurate enough.
We enrolled 730 LAGC patients from five centers in China and one center in Italy, and divided them into one primary cohort, three external validation cohorts, and one international validation cohort. A deep learning radiomic nomogram (DLRN) was built based on the images from multiphase computed tomography (CT) for preoperatively determining the number of LNM in LAGC. We comprehensively tested the DLRN and compared it with three state-of-the-art methods. Moreover, we investigated the value of the DLRN in survival analysis.
The DLRN showed good discrimination of the number of LNM on all cohorts overall C-indexes (95% confidence interval): 0.821 (0.785–0.858) in the primary cohort, 0.797 (0.771–0.823) in the external validation cohorts, and 0.822 (0.756–0.887) in the international validation cohort. The nomogram performed significantly better than the routinely used clinical N stages, tumor size, and clinical model (P < 0.05). Besides, DLRN was significantly associated with the overall survival of LAGC patients (n = 271).
A deep learning-based radiomic nomogram had good predictive value for LNM in LAGC. In staging-oriented treatment of gastric cancer, this preoperative nomogram could provide baseline information for individual treatment of LAGC.
•Evaluation of the lymph node metastasis (LNM) is the basis of individual treatment of locally advanced gastric cancer (LAGC).•Deep leaning radiomic nomogram (DLRN) based on CT images can preoperatively determine the number of LNM in LAGC.•DLRN is significantly superior to the routinely used clinical N stages, tumor size, and clinical model.•DLRN is significantly associated with the overall survival of LAGC.
Two-dimensional (2D) materials have been studied extensively as monolayers, vertical or lateral heterostructures. To achieve functionalization, monolayers are often patterned using soft lithography ...and selectively decorated with molecules. Here we demonstrate the growth of a family of 2D materials that are intrinsically patterned. We demonstrate that a monolayer of PtSe
can be grown on a Pt substrate in the form of a triangular pattern of alternating 1T and 1H phases. Moreover, we show that, in a monolayer of CuSe grown on a Cu substrate, strain relaxation leads to periodic patterns of triangular nanopores with uniform size. Adsorption of different species at preferred pattern sites is also achieved, demonstrating that these materials can serve as templates for selective self-assembly of molecules or nanoclusters, as well as for the functionalization of the same substrate with two different species.
The transport of spin information has been studied in various materials, such as metals, semiconductors and graphene. In these materials, spin is transported by the diffusion of conduction electrons. ...Here we study the diffusion and relaxation of spin in a magnetic insulator, where the large bandgap prohibits the motion of electrons. Spin can still be transported, however, through the diffusion of non-equilibrium magnons, the quanta of spin-wave excitations in magnetically ordered materials. Here we show experimentally that these magnons can be excited and detected fully electrically in a linear response, and can transport spin angular momentum through the magnetic insulator yttrium iron garnet (YIG) over distances as large as 40 μm. We identify two transport regimes: the diffusion-limited regime for distances shorter than the magnon spin diffusion length, and the relaxation-limited regime for larger distances. With a model similar to the diffusion-relaxation model for electron spin transport in (semi)conducting materials, we extract the magnon spin diffusion length λ = 9.4 ± 0.6 μm in a thin 200 nm YIG film at room temperature.
Face-centered cubic (fcc) HEAs, particularly the typical FeCoNiCrMn HEA, are promising for cryogenic applications but generally exhibit relatively low strength at ambient temperature, which limits ...their widespread uses. In this work, we present a systematic study of enhancing simultaneously the strength and ductility of FeCoNiCrMn HEAs via tailoring the phase stability and stacking fault energy (SFE). It was found that in Fe20CoxNi40-xCr20Mn20 (x = 20–30 at.%) HEAs, with the increase of Co, the SFE was gradually decreased and another hcp (hexagonal close-packed) phase was eventually formed in the alloy containing 28 at.% Co. As a result, the deformation mode changes from dislocation glide to mechanical twinning, then to γfcc → εhcp martensitic transformation. Our analysis indicates that the small critical shear stress for twinning resulted from the reduced SFE provides a steady strain hardening rate in a wide strain regime and postpones the plastic instability, eventually leading to the concurrent enhancement in the tensile strength and ductility. Our results not only shed lights on understanding of the effects of SFE on the mechanical properties, but also have important implications on the development of HEAs with a unique combination of high strength and large ductility.
•Increase of the Co content decreases the SFE and phase stability of FeCoNiCrMn alloy.•TRIP effects were achieved with the increase of Co content.•Increase of Co enhances the strength and ductility simultaneously.•Effects of the SFE on deformation mechanism were explored.
Efficient manipulation of magnon spin transport is crucial for developing magnon-based spintronic devices. In this Letter, we provide proof of principle of a method for modulating the diffusive ...transport of thermal magnons in an yttrium iron garnet channel between injector and detector contacts. The magnon spin conductance of the channel is altered by increasing or decreasing the magnon chemical potential via spin Hall injection of magnons by a third modulator electrode. We obtain a modulation efficiency of 1.6%/mA at T=250 K. Finite element modeling shows that this could be increased to well above 10%/mA by reducing the thickness of the channel, providing interesting prospects for the development of thermal-magnon-based logic circuits.
Close white dwarf binaries consisting of a white dwarf and an A-, F-, G-, or K-type main-sequence star, henceforth close WD+AFGK binaries, are ideal systems to understand the nature of type Ia ...supernovae progenitors and to test binary evolution models. In this work we identify 775 WD+AFGK candidates from TGAS (The Tycho-Gaia Astrometric Solution) and Gaia Data Release 2 (DR2), a well-defined sample of stars with available parallaxes, and we measure radial velocities (RVs) for 275 of them with the aim of identifying close binaries. The RVs have been measured from high-resolution spectra obtained at the Xinglong 2.16 m Telescope and the San Pedro Mártir 2.12 m Telescope and/or from available LAMOST DR6 (low-resolution) and RAVE DR5 (medium-resolution) spectra. We identify 23 WD+AFGK systems displaying more than 3 RV variation among 151 systems for which the measured values are obtained from different nights. Our WD+AFGK binary sample contains both AFGK dwarfs and giants, with a giant fraction ∼43%. The close binary fractions we determine for the WD+AFGK dwarf and giant samples are 24% and 15%, respectively. We also determine the stellar parameters (i.e., effective temperature, surface gravity, metallicity, mass, and radius) of the AFGK companions with available high-resolution spectra. The stellar parameter distributions of the AFGK companions that are members of close and wide binary candidates do not show statistically significant differences.
•A principle of convective heat transfer enhancement was proposed based on exergy destruction minimization.•An optimal field of longitudinal whirling flow with vortexes was obtained by convective ...heat transfer minimization.•An insert of center-connected awl-shaped slices was studied by numerical simulation and a PIV experiment.
Enhancing convective heat transfer, by strengthening fluid disturbance, is an effective way of raising the utilization efficiency of an energy system. In this study, in order to introduce a principle for convective heat transfer enhancement, a physical quantity called available potential was defined, and an equation of available potential was derived to obtain an expression of local exergy destruction caused by heat transfer and fluid flow. Then, a mathematical model of convective heat transfer optimization was established by adopting adequate objective function and constraint condition based on exergy destruction minimization, and an optimal flow field of longitudinal whirling flow with multi-vortexes was obtained by solving the optimization controlling equations. Finally, through numerical simulation and a PIV experiment, a heat transfer unit consisting of center-connected awl-shaped slices was studied to realize longitudinal whirling flow with multi-vortexes in a tube, which indicated an excellent effect of heat transfer enhancement.
Tea is the world's most popular non-alcoholic beverage. China and India are known to be the largest tea producing countries and recognized as the centers for the domestication of the tea plant ...(Camellia sinensis (L.) O. Kuntze). However, molecular studies on the origin, domestication and relationships of the main teas, China type, Assam type and Cambod type are lacking.
Twenty-three nuclear microsatellite markers were used to investigate the genetic diversity, relatedness, and domestication history of cultivated tea in both China and India. Based on a total of 392 samples, high levels of genetic diversity were observed for all tea types in both countries. The cultivars clustered into three distinct genetic groups (i.e. China tea, Chinese Assam tea and Indian Assam tea) based on STRUCTURE, PCoA and UPGMA analyses with significant pairwise genetic differentiation, corresponding well with their geographical distribution. A high proportion (30%) of the studied tea samples were shown to possess genetic admixtures of different tea types suggesting a hybrid origin for these samples, including the Cambod type.
We demonstrate that Chinese Assam tea is a distinct genetic lineage from Indian Assam tea, and that China tea sampled from India was likely introduced from China directly. Our results further indicate that China type tea, Chinese Assam type tea and Indian Assam type tea are likely the result of three independent domestication events from three separate regions across China and India. Our findings have important implications for the conservation of genetic stocks, as well as future breeding programs.
SFTS virus (SFTSV) is a novel bunyavirus that causes severe fever with thrombocytopenia syndrome (SFTS), an emerging infectious disease that occurred in China in recent years, with an average case ...fatality rate of 10–12%. Intervention in the early clinical stage is the most effective measure to reduce the mortality rate of disease. To elucidate the natural course of and immune mechanisms associated with the pathogenesis of SFTSV, 59 laboratory-confirmed SFTS patients in the acute phase, who were hospitalized between October 2010 and September 2011, were enrolled in this study, and the patients sera were dynamically collected and tested for SFTSV viral RNA load, 34 cytokines or chemokines and other related laboratory parameters. All clinical diagnostic factors in the acute phase of SFTS were evaluated and assessed. The study showed that the severity of the disease in 11 (18.6%) patients was associated with abdominal pain (p 0.007; OR = 21.95; 95% CI, 2.32–208.11) and gingival bleeding (p 0.001; OR = 122.11; 95% CI, 6.41–2328). The IP-10, TNF-α, IL-6, IL-10, granzyme B and HSP70 levels were higher over the 7–8 days in severe cases, accompanied by altered AST, CK and LDH levels. HSP70 (p 0.012; OR = 8.29; 95% CI, 1.58–43.40) was independently correlated with the severity of the early acute phase of SFTSV infection. The severity of SFTS can be predicted based on the presence of symptoms such as abdominal pain and gingival bleeding and on the level of HSP70 in the acute phase of the disease.
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