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Silicon–based materials are among the highly promising anode candidates for Li–ion batteries owing to their excellent theoretical energy density. However, the huge volume variation makes the application of silicon anode in lithium–ion batteries be full of challenge. Herein, high–performance Si@C@rGO composites anode for lithium–ion batteries are successfully prepared by graphene oxide (GO) uniformly encapsulating resorcinol–formaldehyde resin (RF) coated silicon nanoparticles. The RF‐derived carbon layer can prevent the silicon from direct contact with the electrolyte. Furthermore, the continuous conductive graphene network not only improves the overall electrical conductivity of the composite material, but also can be reversibly deformed with the volume change of silicon during the charging and discharging process, thus greatly improving the structural stability of the anode. The optimal Si@C@rGO‐2 composite provides a high specific capacity of 743.9 mAh g−−1 after 300 cycles at a current density of 1 A g−1. Meanwhile, the material also exhibits good rate performance, showing a good reversible capacity of 719.5 mAh g−1 even at a high current density of 2 A g−1. In addition, this simple and low‐cost strategy of Si@C@rGO anode can provide a design reference for the further development of anode materials in lithium–ion batteries. [ABSTRACT FROM AUTHOR]

Microstructure, texture evolution and strain hardening behaviour of the Mg-1Y and Mg-1Zn (wt%) alloys were investigated under room temperature compression. Microstructural characterization was performed by optical microscopy, scanning electron microscopy, electron back scattered diffraction and transmission electron microscopy. The experimental results show that Mg-1Zn alloy exhibits conventional three-stage strain hardening curves, while Mg-1Y alloy exhibits novel six-stage strain hardening curves. For Mg-1Y alloy, rare earth texture leads to weak tensile twinning activity in compression and consequently results in a moderate evolution to <0001> texture. Moreover, inefficient tensile twinning activity and weak slip-twinning interaction give rise to excellent ductility and high hardening capacity but low strain hardening rate. For Mg-1Zn alloy, basal texture leads to pronounced tensile twinning activity in compression and consequently results in rapid evolution to <0001> texture. The intense tensile twinning activity and strong slip-twinning interaction lead to high strain hardening rate but poor ductility and low hardening capacity. [ABSTRACT FROM AUTHOR]

In common with other important coal bases in northwestern China, the hydrology and ecology and environment of Ordos, northern Shaanxi (Shanbei), and Shanxi Provinces have much. Terrestrial water storage anomaly (TWSA), soil moisture anomaly (SMA), and groundwater storage anomaly (GWSA), are important water storage qualities that play a critical role in the distribution and growth of vegetation. In this paper, multi‐source remote sensing data were used to analyze the spatial–temporal changes and relationships of water storage, ecology and environment from 2002 to 2020. The numerical results showed the TWSA and GWSA in the study area had a declining trend and the rates were −7.512 mm yr‐1 and −8.268 mm yr‐1, respectively. On the contrary, the SMS showed an increasing trend, and the rate was 0.840 mm yr‐1. By trend variation and correlation analysis, we found GWSA is the main part in the variation of TWSA. By further analysis, it was found that the climate factors are not the major factors causing the variation of GWSA, but coal mining and artificial irrigation activities, which are especially clear in the Taihang Mountains in eastern Shanxi Province. The ecology and environment have been improving, and water storage and climate factors have played a different role in different regions. The warm climate conditions and the increased 0–40 cm of soil water have promoted the growth of vegetation and the improvement of the ecology and environment. The research results are helpful to understand the impacts of water storage on the ecology and environment in high‐intensity coal mining areas. [ABSTRACT FROM AUTHOR]

Semiactive laser (SAL) guidance is a point-source detection technology without target feature extraction ability. In this article, the quadrant detector (QD)-based seeker and a spatially modulated designator are used in cooperation to achieve image-free target classification via a hybrid convolutional neural network (CNN) architecture. The convolutional layer is implemented optically by illuminating the target with training-obtained modulated patterns, and the detected intensity signals are regarded as compressed target features. The convolutional layers and classification net are trained together on an electronic platform. Layer normalization (LN) is adopted to improve network generalization ability and accelerate the training process. Network hyperparameters such as the channel numbers and kernel sizes of convolutional layers are analyzed and selected. The feasibility and robustness of the network are verified by both numerical simulation and experiments, whose classification accuracies are 88% and 66%, respectively. The proposed SAL detection and classification system is calculation-efficient and convenient to be adopted in existing guidance platforms or other real-time applications with limited computing resources. [ABSTRACT FROM AUTHOR]

The leakage of underground natural gas has a negative impact on the environment and safety. Trace amounts of gas leak concentration cannot reach the threshold for direct detection. The low concentration of natural gas can cause changes in surface vegetation, so remote sensing can be used to detect micro-leakage indirectly. This study used infrared thermal imaging combined with deep learning methods to detect natural gas micro-leakage areas and revealed the different canopy temperature characteristics of four vegetation varieties (grass, soybean, corn and wheat) under natural gas stress from 2017 to 2019. The correlation analysis between natural gas concentration and canopy temperature showed that the canopy temperature of vegetation increased under gas stress. A GoogLeNet model with Bilinear pooling (GLNB) was proposed for the classification of different vegetation varieties under natural gas micro-leakage stress. Further, transfer learning is used to improve the model training process and classification efficiency. The proposed methods achieved 95.33% average accuracy, 95.02% average recall and 95.52% average specificity of stress classification for four vegetation varieties. Finally, based on Grad-Cam and the quasi-circular spatial distribution rules of gas stressed areas, the range of natural gas micro-leakage stress areas under different vegetation and stress durations was detected. Taken together, this study demonstrated the potential of using thermal infrared imaging and deep learning in identifying gas-stressed vegetation, which was of great value for detecting the location of natural gas micro-leakage. [ABSTRACT FROM AUTHOR]

The influence of primary and secondary extrusion on the microstructure and mechanical properties of the Mg-12Gd-2Er-0.4Zr alloy was investigated. After the primary extrusion, incomplete dynamic recrystallization (DRX) had led to the formation of non-homogenous grain structure with fine equiaxed grain and coarse grains, while the secondary extrusion refined the microstructure remarkably and further improved the mechanical properties. Moreover, the secondary phases were broken into small particles and distributed along the extrusion direction (ED). The secondary extruded (EX2) alloy had the smallest grain size ~3.0 µm and exhibited the best balance of strength and elongation (ultimate tensile strength (UTS) of 305 ± 5.7 MPa, tensile yield strength (TYS) of 258 ± 10 MPa, and elongation (EL) of 31 ± 2.4%). The excellent EL was mainly ascribed to the fully refined dynamic recrystallized (DRXed) grains after the secondary extrusion. Furthermore, the aged EX2 alloy (AEX2) exhibited an excellent balance of strength and elongation (TYS of 382 ± 11 MPa, UTS of 423 ± 6.2 MPa, and EL of 7.6 ± 0.9%). The alloy strengthening was mainly attributed to the refined grains and strong precipitation strengthening. [ABSTRACT FROM AUTHOR]

Background: Persistent infection with hepatitis B virus (HBV) accounts for the majority of hepatocellular carcinoma (HCC), but the molecular mechanisms underlying liver carcinogenesis are still not completely understood. Increasing evidence demonstrates that microRNAs (miRNAs) play significant functional roles in virus–host interactions. The aim of this study was to explore differentially expressed miRNA profiles and investigate the molecular mechanism of miR-0308-3p in HBV-positive HCC carcinogenesis. Methods: High-throughput sequencing was used to detect novel miRNAs in three samples of HBV-positive HCC tissue compared to matched HBV-negative HCC tissue. The Cancer Genome Atlas (TCGA) database was used to mine miRNAs related to HBV-positive HCC. Bioinformatics analyses were conducted to predict the miRNAs' possible biological and pathway regulatory functions. Quantitative polymerase chain reaction (qPCR) was then applied to evaluate the expression levels of randomly selected miRNAs. CCK-8 was used to measure cell proliferation and cell cycles were analyzed using flow cytometry. A dual luciferase reporter gene assay was used to confirm the downstream targets of miR-0308-3p. Results: In total, there were 34 overlapping miRNAs in both our miRNA-seq data and the TCGA database. We found two overlapping miRNAs in both the HBV-positive HCC samples and the TCGA database, and 205 novel pre-miRNA sequences were predicted. miR-522 and miR-523 were markedly overexpressed in HBV-positive HCC and were associated with a significantly poorer long-term prognosis (miR-522, HR 2.19, 95% CI 1.33–3.6, p = 0.0015; miR-523HR 1.5, 95% CI 1–2.44, p = 0.0047). Of note, we found that the novel miR-0308-3p was markedly downregulated in HBV-positive HCC samples and HCC cancer cell lines compared with HBV-negative HCC samples and adjacent normal hepatic tissue. Moreover, elevated expression of miR-0308-3p was found to inhibit proliferation of cancer cells by promoting G1/S cell cycle arrest but did not influence the apoptosis of cancer cells. A dual luciferase reporter activity assay identified that miR-0308-3p acted directly on the target sequence of the CDK6 and Cyclin D1 mRNA 3ʹUTR to suppress CDK6 and Cyclin D1 expression. Conclusions: MiR-0308-3p upregulation dramatically suppressed HCC cell proliferation and induced G1/S cell cycle arrest by directly targeting CDK6/Cyclin D1. These findings reveal a novel molecular mechanism for activation of G1/S arrest in HCC and may prove clinically useful for developing new therapeutic targets. [ABSTRACT FROM AUTHOR]

This study investigates the effects of the extrusion ratio and annealing treatment on the microstructure, texture and mechanical properties of an as-extruded Mg -11Gd -4.5Y -1Nd -1.5Zn -0.5Zr (wt%) alloy. A high extrusion ratio (30:1) results in a homogeneous microstructure with fine dynamic recrystallized (DRXed) grains, while a low extrusion ratio (6:1) leads to a bimodal microstructure with un-DRXed regions and DRXed grains. The bimodal microstructure can be removed by subsequent annealing. This alloy contains several long-period stacking ordered (LPSO) and MgRE phases (RE: rare earth). The extrusion ratio and annealing process have negligible effects on the volume fraction of the LPSO phase but have significant effects on the MgRE phase. The volume fraction of the MgRE phase decreases as the extrusion ratio and annealing time increase. Cuboid precipitates form in the alloy extruded at low extrusion ratios after annealing. The alloy exhibits a bimodal texture with <0001> and < $$ 10\overline{1} 0 $$ > components. The presence of the <0001> component is determined by a critical grain size. The texture evolution (such as the degree of grain growth) is not influenced by the extrusion ratio, but it is affected by the annealing time, which is related to the MgRE phase rather than the LPSO phase. The grain refinement, the MgRE and LPSO phases, and the texture contribute to the alloy strengthening. Finally, a high-strength extruded Mg bar with a diameter of 32 mm (an extrusion ratio of 6:1) was successfully produced. [ABSTRACT FROM AUTHOR]

When laser interferometry is applied to measure the form deviation of a helical tooth flank, dense interference fringes are almost inevitable because of the distorted shape of the helical tooth flank. The high-density fringe leads to poor processing accuracy of interferograms and is an important indicator of the interferogram quality. An optical path optimization method based on position errors analysis is proposed to modulate the fringe density. First, some factors that may affect fringe density in the optical system are modeled. Consequently, the incident angle of the measured light is proved to be the main factor affecting the fringe density and is the primary parameter that modulates the interference fringe density. Subsequently, an analytical model is established, and a fringe density modulation method based on the optimized incident angle is proposed for designing the optical path. Finally, simulated and actual experimental results are provided to verify the correctness of the analysis of the main factor affecting the fringe density and feasibility of the modulation method. [ABSTRACT FROM AUTHOR]

Research of interactions between in-channel vegetation and flow structure is important for the restoration of aquatic ecosystems. This study aims to investigate the impact of the vegetation patch density on the wake structure. We used uniform fiberglass circular cylinders to simulate the non-submerged rigid plant community. In addition, a wide range of vegetation patch densities was considered and a 3D acoustic Doppler velocimeter (ADV) was used to measure local flow velocities. High-density vegetation patches correlated with a high maximum turbulent kinetic energy and a double-peak phenomenon for the lateral distribution. In conclusion, differences between Reynolds shear stresses near the bed surface upstream and downstream of vegetation patches correlate with the vegetation density. [ABSTRACT FROM AUTHOR]

Flood discharge and sediment transport are closely linked to channel resistance in steep mountain streams. Previous research has mainly focused on the resistance of fixed-bed channels with steep gradients and mobile-bed channels in alluvial rivers. The present study performs an experiment and establishes a calculation method for the fixed-bed resistance of mountain channels. The basic expression of the mobile-bed resistance of steep mountain channels is derived by determining the controlling factors of the bed load movement on the riverbed resistance. The proposed formula can accurately predict the variation of the bed load resistance. The results of the present research improve the understanding of fluid dynamics and sediment transport in steep mountain channels. [ABSTRACT FROM AUTHOR]