Search

• A CALPHAD-aided strategy is implemented to design a high-performance Ni 45.9 Fe 23 Cr 23 V 4 Nb 3 Mo 1 B 0.1 (at.%) medium entropy alloy strengthened by D0 22 nanoparticles. • The newly designed alloy exhibits excellent mechanical properties at both room and intermediate temperatures, with ultimate tensile strength and fracture elongation of ∼845 MPa and 27.5 % at 700 °C, respectively, and ∼589 MPa and 24.3 % at 800 °C, respectively. • The superior combination of strength and ductility over a wide temperature range is primarily attributed to the high-density interactions of planar dislocation configurations (mainly stacking faults) and the shearable D0 22 nanoparticles. • Anomalous deformation twinning at 800 °C can be activated due to the localized stress concentration, the locally low stacking-fault energy, and especially the high diffusion rate at grain boundaries. Precipitation-strengthened medium/high-entropy alloys (MEAs/HEAs) have great potential for high-temperature applications. In this study, we designed a novel Ni 45.9 Fe 23 Cr 23 V 4 Nb 3 Mo 1 B 0.1 (at.%) MEA alloy, hardened by the D0 22 (Ni, Fe, Cr) 3 (Nb, V)-type nanoprecipitates, with an excellent strength-ductility combination from room to elevated temperatures. Specifically, the tensile strengths, at 700 and 800 °C, could be maintained as high as 845 and 589 MPa, respectively; meanwhile, elongations at all testing temperatures exceeded 25 % without any intermediate-temperature embrittlement. The temperature-dependent deformation mechanisms were unraveled using multi-scale characterizations, which involved profound slip planarities, such as stacking fault (SF) networks and deformation twins (DTs). Furthermore, the critical resolved shear stress (CRSS) to initiate SFs in both face-centered cubic (FCC) and D0 22 phases was evaluated, and the possible reasons for the origin of anomalous DTs at 800 °C were discussed in detail. The main findings demonstrate that the shearable D0 22 nanoparticles can provide the FCC matrix with considerable dislocation storage capacity, reinforcing strain hardening at ambient and intermediate temperatures. This work provides fundamental insights into the controllable design and deformation mechanisms of high-performance D0 22 -strengthened MEAs/HEAs. [Display omitted] [ABSTRACT FROM AUTHOR]

Acquiring descriptors to guide catalyst design is an ideal but challenging topic in the field of heterogeneous catalysis. Herein, the adsorption energy of H* (Ead(H)) has been established to describe the catalytic activity of dual-active sites of single-atom metals and frustrated Lewis pairs (FLPs) on the porous nanorod of CeO2surface (M1/PN-CeO2) for reverse water-gas shift (RWGS) reaction. H2and CO2molecules are adsorbed and activated on single-atom metals and FLP sites, respectively, facilitating the RWGS reaction through the H* spillover from single-atom metals to PN-CeO2supports. Mechanistic investigations illustrate that the generation of H* on the single-atom metals and subsequent migration towards FLP are critical steps, determining the performance of M1/PN–CeO2for RWGS reaction. A volcanic correlation is observed between Ead(H) and catalytic activity of M1/PN–CeO2for RWGS. The Pt1/PN–CeO2catalysts with a minimal deviation of −0.01 eV from the experimentally optimized Ead(H) of −1.88 eV, exhibited an exceptional turnover frequency of 33,605 h−1and surpassed a turnover number of 20,000,000 for each Pt active site during a period of 650 h at 600 °C. These findings could pave the way for the rational design of highly active and durable catalysts for RWGS reaction.

For the remaining useful life (RUL) prediction of complex systems, some data in a large amount of multisensor monitoring data do not effectively characterize the degradation of complex systems, while there is redundancy between sensor data, which leads to low accuracy of prediction results. Therefore, a high-dimensional kernel density estimation (KDE) RUL prediction method was proposed with an adaptive relative density window width based on multisource information fusion, which contains a multiindicator sensor evaluation algorithm based on the entropy weight method and the maximum relevance–minimum redundancy (mRMR) sensor selection algorithm. First, the trendability, monotonicity, predictability, and robustness are proposed to evaluate the sensor data based on the mapping relationship between the sensor data and random degradation characteristics of the system. Moreover, a comprehensive evaluation indicator is constructed using the entropy weighting method to select sensors with higher comprehensive scores, which can better characterize the system degradation. Furthermore, an mRMR based on mutual information (MI) is proposed to select the sensor group that has the maximum relevance to the runtime and minimum redundancy of information between multisensor data. Moreover, a high-dimensional KDE RUL prediction model with adaptive relative density window width is established based on feature-level information fusion. Finally, the accuracy and effectiveness of the proposed method are verified by C-MAPSS data and N-MAPSS.

The Nod‐like receptor (NLR) family CARD domain containing 5 (NLRC5) has been reported as an activator of human leukocyte antigen (HLA) class I that is responsible for immune activity in cancer treatment. This work focuses on the role of BMI1 proto‐oncogene (BMI1) in the NLRC5‐HLA class I axis and in immune escape in non‐small cell lung cancer (NSCLC). First, immunoblot analysis and/or reverse transcription‐quantitative polymerase chain reaction were performed, which identified decreased NLRC5 and HLA class I levels in NSCLC tissues and cell lines. NSCLCs were co‐cultured with activated CD8+T cells. Overexpression of NLRC5 in NSCLC cells elevated the expression of HLA class I and increased the activity of T cells and IL‐2 production, and it reduced the PD‐1/PD‐L1 levels. The ubiquitination and immunoprecipitation assays confirmed that BMI1 bound to NLRC5 to induce is ubiquitination and protein degradation. Downregulation of BMI1 in NSCLC cells elevated NLRC5 and HLA class I levels, and consequently promoted T cell activation and decreased PD‐1/PD‐L1 levels in the co‐culture system. However, overexpression of BMI1 in cells led to inverse trends. In summary, this study demonstrates that BMI1 induces ubiquitination and protein degradation of NLRC5 and suppresses HLA class I expression, which potentially helps immune escape in NSCLC.

A helium ion beam (HIB) is ideal for milling monolayer graphene in nanopore applications, but the optimizing irradiation parameter requires a comprehensive microscopic understanding of the interaction between helium ions and the suspended graphene. In this work, we investigate the influence of the substrate hole shape on the interaction between helium ions and suspended monolayer graphene on a substrate with periodic structures of different shapes. Raman spectroscopy is used to correlate the dose of HIB irradiation with engineered defects on freestanding monolayer graphene. Raman characteristics of the suspended monolayer graphene are related to the pore size and shape of the supporting substrate upon helium ion irradiation. These provide insights into the influence of the substrate hole shape on the interaction between helium ions and a freestanding graphene membrane. Our results can be used to analyze ion–membrane interactions in the other suspended monolayer two-dimensional materials for sub-nanometer precision nanopore fabrication.

Exploration of cost-effective Pt/C catalysts has been a significant issue for electrochemical hydrogen evolution reaction (HER) toward sustainable energy conversion and storage. Herein, we report a fabrication strategy by employing platelet carbon nanofibers (p-CNF) as the support to immobilize Pt-CoO HER electrocatalyst using atomic layer deposition method. The edge-rich p-CNF support is found to act as the anchoring sites of Pt nanoparticles and favorably capture electrons from Pt to yield electron-deficient Pt surfaces for the boosted HER. Additionally, the sequential growth of CoO onto the Pt/p-CNF catalyst elaborately constructs the Pt-CoO interface and facilitates the electron transfer from Pt to CoO, which further enhances the HER activity. These advantages endow the fabricated Pt-CoO/p-CNF catalyst with the superior HER activity, e.g., a very low overpotential of 26 mV at the current density of 10 mA·cm−2and a mass activity of 4.42 A·mgPt−1at the overpotential of 30 mV, 18.8 times higher than that of the commercial 20 wt% Pt/C catalyst. The insights reported here could shed light on for the fabrication of cost-effective Pt-based composite HER catalysts.

The controllable synthesis of stable single-metal site catalysts with an expected coordination environment for high catalytic activity and selectivity is still challenging. Here, we propose a cation-exchange strategy for precise production of an edge-rich sulfur (S) and nitrogen (N) dual-decorated single-metal (M) site catalysts (M = Cu, Pt, Pd, etc.) library. Our strategy relies on the anionic frameworks of sulfides and N-rich polymer shell to generate abundant S and N defects during high-temperature annealing, further facilitating the stabilization of exchanged metal species with atomic dispersion and excellent accessibility. This process was traced by in situ transmission electron microscopy, during which no metal aggregates were observed. Both experiments and theoretical results reveal the precisely obtained S, N dual-decorated Cu sites exhibit a high activity and low reaction energy barrier in catalytic hydroxylation of benzene at room temperature. These findings provide a route to controllably produce stable single-metal site catalysts and an engineering approach for regulating the central metal to improve catalytic performance.

Understanding carbon-supported Pt-catalyzed oxygen reduction reaction (ORR) from the perspective of the active sites is of fundamental and practical importance. In this study, three differently sized carbon nanotube-supported Pt nanoparticles (Pt/CNT) are prepared by both atomic layer deposition (ALD) and impregnation methods. The performances of the catalysts toward the ORR in acidic media are comparatively studied to probe the effects of the sizes of the Pt nanoparticles together with their distributions, electronic properties, and local environments. The ALD-Pt/CNT catalysts show much higher ORR activity and selectivity than the impregnation-Pt/CNT catalysts. This outstanding ORR performance is ascribed to the well-controlled Pt particle sizes and distributions, desirable Pt04fbinding energy, and the Cl-free Pt surfaces based on the electrocatalytic measurements, catalyst characterizations, and model calculations. The insights reported here could guide the rational design and fine-tuning of carbon-supported Pt catalysts for the ORR.

ZnO has attracted considerable attention as an ultraviolet (UV) light emitting material. Many efforts have been made to promote efficiency for UV emission. We report large enhancement in UV emission from ZnO nanorod (NR) arrays by covering with Ti coatings. Together with morphology and structure characterization, the capability of UV emission from the Ti-coating-covered ZnO (Ti/ZnO) NR arrays was evaluated by systematically examining the photoluminescence at room and low temperatures. At room temperature, the bare ZnO NR arrays are capable of emitting a photoluminescence composed of a strong UV near-band-edge (NBE) emission of ZnO and a weak visible emission associated with deep-level defects in ZnO. The UV NBE emission is enhanced by about 24 times after covering the ZnO NR arrays with Ti coatings. The UV NBE emission increases drastically as the temperature drops, with the increase of the UV NBE emission of the Ti-covered ZnO NR arrays being much faster than that of the bare ZnO NR arrays. The UV NBE emission of the Ti/ZnO NR array is increased by about 175 times when the temperature drops from room temperature to 10 K. Compared to the UV NBE emission of the bare ZnO NR arrays, a 70-fold enhancement in the UV NBE emission of the Ti-covered ZnO NR arrays is obtained at 10 K.

The long-lasting wounding of lung tissue that results in pulmonary fibrosis is a long-term, gradual lung condition that eventually impairs breathing and causes respiratory failure. For decades, people from a variety of cultures have used phytoceuticals for their therapeutic benefits, providing a holistic and natural approach to treatment. Phytoceuticals are well-known compound that consists of active ingredients that are extracted from plants and produces therapeutic effects in treating pulmonary fibrosis. In this review, the plants that were discussed to manage pulmonary fibrosis include Quercetum, chamomile, thyme, parsley, garlic, guava, broccoli, Curcuma longa, Scutellariae radix, Erigeron breviscapus, Moraceae, Ruta graveolens. Other than that, the mechanism of action of the type of pulmonary fibrosis and drug delivery through inhalation also discussed. The nanoparticles that can be used in drug delivery include liposomes, poly(lactic-co-glycolic acid), dextran, acetalated dextran, polymeric micelle, lyotropic liquid crystalline and polyethylene glycol (PEG).

Fundamental understanding of the structure sensitivity of Au-catalyzed H2O2formation from H2with O2is of prime scientific and industrial significance. Herein, DFT calculations are employed to reveal the underling nature of the site-dependent H2O2formation activity and selectivity over three typical Au(111), Au(100), and Au(211) sites. The hydrogen dissociation is suggested as the rate-determining step. The structural and charge analysis and the energy barrier decomposition indicate one lower-coordinated edge atom on the Au(211) as the active site for hydrogen dissociation. Furthermore, competition reactions between hydrogenation/desorption of the species involving the O–O bonds and their cleavage are comparatively studied. Au(111) is found to exhibit the highest selectivity to H2O2. Finally, a combination of the low-coordinated Au atom with Au(111) is proposed as the catalytically active center of H2O2formation. The results demonstrated here could be valuable for fabricating highly active and selective catalysts for H2O2formation.

Three-dimensional (3D) co-seismic surface deformations are of great importance to interpret the characteristics of coseismic deformations and to understand the geometries and dynamics of seismogenic faults. In this paper, we propose a method for mapping 3D co-seismic deformations based on InSAR observations and crustal strain characteristics. In addition, the search strategy of correlation points is optimized by adaptive correlation distance, which greatly improves the applicability of the proposed method in restoring deformations in decorrelation areas. Results of the simulation experiment reveal that the proposed method is superior to conventional methods in both the accuracy and completeness. The proposed method is then applied to map the 3D co-seismic surface deformations associated with the 2015 MW7.2 Murghab earthquake using ascending and descending ALOS-2 PALSAR-2 images. The results show that the seismogenic fault is the Sarez-Karakul fault (SKF), which is dominated by NE-SW strike slips with an almost vertical dip angle. The north section and the south segment near the epicentre have obvious subsidence along with a southwestward motion in the northwest wall, and the southeast wall has northeast movement and surface uplift trend along the fault zone. The strain field of the earthquake is also obtained by the proposed method. It is found that the crustal block of the seismic area is obviously affected by dilatation and shear forces, which is in good agreement with the movement character of the sinistral slip.

BackgroundExtensive cardiac echography examination (ECEE) can identify cardiac heart defects (CHDs) in utero. However, there is not yet a clear appraisal of ECEE’s performance in detecting foetal CHDs as a function of gestational time. In this study, we assessed the diagnostic efficacy of ECEE in detecting CHDs during early gestation (< 18 weeks) and late gestation (≥ 18 weeks).MethodsMEDLINE, EMBASE, and Cochrane CENTRAL databases were searched for ECEE studies that had a prenatal diagnosis later validated by echocardiography, catheterization, surgery, or autopsy and allowed construction of 2 × 2 tables. Pooled sensitivity, specificity, and diagnostic odds ratio of ECEE during early and late gestation were calculated. Summary receiver operating characteristic curves were plotted to obtain area under the curve (AUC) values.ResultsECEE in late gestation had a slightly superior sensitivity relative to that in early gestation (0.90 vs 0.86, respectively), while ECEE during both early and late gestation displayed near-perfect specificity (1.00 vs 1.00, respectively). ECEE in late gestation displayed a superior diagnostic odds ratio relative to that in late gestation (3,502.81 vs 1,076.79, respectively). ECEE during both early and late gestation displayed similar overall diagnostic accuracy in terms of AUC (0.9861 vs 0.9783, respectively).ConclusionsECEE performed before the 18-week gestational time point provides nearly equivalent diagnostic accuracy to ECEE performed on or after the 18-week gestational time point. However, ECEE conducted prior to week 11 may not be advisable due to the immature development of foetal heart structures.

In this study, system maintenance and production scheduling are jointly decided to solve the problems of resource idleness and time cost increase due to system maintenance in the processing of production scheduling. Based on the previous research on the integration of scheduling and maintenance of single machine and multi machine, considering the deterioration and economic dependence of each component in the system, a joint strategy of multi component condition-based maintenance combined with production scheduling is formulated. All the maintenance combinations and probability calculation formulas in the production scheduling process are developed using the deterioration state space partition method, and the probability density function and its numerical solution method are derived. A joint decision model is established to minimize the total weighted expected completion time. Finally, taking the KS5 adjustable multi axis tapping machine as an example, numerical experiments were conducted to verify the correctness of the proposed strategy and the established model.