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Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Foam concrete is characterized by lightweight, self-compacting and high flowability, thereby widely used as a subgrade bed filler. High-speed railway subgrades usually experience inhomogeneous deformation due to the occurrence of freezing-thawing cycles in seasonally frozen soil areas. It is essential to study the deformation behavior of foam concrete under the coupling effect of freezing-thawing cycles and dynamic loading. In this paper, dynamic triaxial tests were performed to study the accumulative deformation of the foam concrete under different numbers of freezing-thawing cycles, freezing temperatures, amplitudes and frequencies of dynamic loading. Based on the scanning electron microscopy (SEM) tests, the characteristics of the pore structure were analyzed quantitatively by introducing the directional distribution frequency and fractal dimension. The research results illustrate that the damage caused by freezing-thawing progress to the pore structure results in more significant deformation of the foam concrete subjected to dynamic loading. There exists an accumulative damage effect induced by the coupling action of long-term dynamic loading and freezing-thawing progress on the microstructure and mechanical properties of foam concrete. The development of the fractal dimension agrees with that of the accumulative strain, indicating a close connection between the microstructure and the dynamic behavior of foam concrete. The findings concluded in this study contribute to a sufficient understanding of the performance of foam concrete used as high-speed railway subgrade fillers subjected to seasonal freezing. [ABSTRACT FROM AUTHOR]

Angelica dahurica (A. dahurica) has a wide range of pharmacological effects, including analgesic, anti-inflammatory and hepatoprotective effects. In this study, we investigated the effect of A. dahurica extract (AD) and its effective component bergapten (BG) on hepatic fibrosis and potential mechanisms. Hepatic fibrosis was induced by intraperitoneal injection with carbon tetrachloride (CCl4) for 1 week, and mice were administrated with AD or BG by gavage for 1 week before CCl4 injection. Hepatic stellate cells (HSCs) were stimulated by transforming growth factor-β (TGF-β) and cultured with AD, BG, GW4064 (FXR agonist) or Guggulsterone (FXR inhibitor). In CCl4-induced mice, AD significantly decreased serum aminotransferase, reduced excess accumulation of extracellular matrix (ECM), inhibited caspase-1 and IL-1β, and increased FXR expressions. In activated HSCs, AD suppressed the expressions of α-SMA, collagen I, and TIMP-1/MMP-13 ratio and inflammatory factors, functioning as FXR agonist. In CCl4-induced mice, BG significantly improved serum transaminase and histopathological changes, reduced ECM excessive deposition, inflammatory response, and activated FXR expression. BG increased FXR expression and inhibited α-SMA and IL-1β expressions in activated HSCs, functioning as GW4064. FXR deficiency significantly attenuated the decreasing effect of BG on α-SMA and IL-1β expressions in LX-2 cells. In conclusion, AD could regulate hepatic fibrosis by regulating ECM excessive deposition and inflammation. Activating FXR signaling by BG might be the potential mechanism of AD against hepatic fibrosis. [ABSTRACT FROM AUTHOR]

In the context of long-distance cross-basin water transfer projects, the water conveyance tunnel serves as a pivotal component in mitigating regional disparities between economic development and water resources allocation. However, in high seismic-intensity areas of southwest China, geological complexities and densely distributed active faults present formidable challenges. Consequently, the construction of water conveyance tunnels necessitates traversing one or more active fault zones. This study examines the impact of an adaptive tunnel structure in the presence of fault dislocation, focusing on the Xianglushan Tunnel, a constituent of the Central Yunnan Water Diversion Project. Taking the Longpan-Qiaohou Fault F10-1 as a case study, we assess the influence of active faults on the anti-dislocation adaptive structure of the Xianglushan Tunnel, considering factors such as displacement, relative deformation, maximum principal stresses, and longitudinal equivalent internal force in critical tunnel sections. Numerical calculations validate the efficacy of this adaptive structure in reducing induced internal forces and deformations of the tunnel lining. The results show that, under the influence of strike-slip dominated fault movement, one side of the tunnel exhibits tensile stress, with a magnitude of approximately 5 MPa. The maximum normal and tangential deformation of the hinge joint is concentrated in the central section of the fault zone. The incorporation of an articulated adaptive design significantly enhances the stress state of lining under dislocation condition. These research results directly inform the engineering design and construction of water conveyance tunnels traversing active fault regions, providing valuable guidance for related tunnel construction endeavors. [ABSTRACT FROM AUTHOR]

Determining the shear strength of rock joint surfaces is a fundamental problem in the fields of rock mechanics and engineering geology. To obtain the cyclic shear strength of rock joint surfaces under cyclic shearing conditions, an improved formula is proposed. First, cubic splitting tests are used to fabricate joint surfaces and prepare experimental specimens with simulated materials. Second, a series of laboratory cyclic shear tests and data analysis are conducted to investigate the effects of the normal stress, the number of shearing cycles, the rock wall strength, and the surface roughness on the mechanical and morphological properties of the rock joints. The maximum shear strength of the joint surface increases with the normal stress, the rock wall strength, and the joint surface roughness. Considering morphological properties, the normalized values of the indices decrease with the normal stress, the number of shearing cycles, and the joint surface roughness increase, while they increase with increasing rock wall strength. Third, the accuracy of the Adhesive Friction Theory-Barton empirical formula is verified by fitting the experimental data to calculation results. Finally, based on the negative exponential degradation assumption, a new formula is proposed to calculate shear strength under cyclic shear conditions. The proposed calculation method can provide a theoretical reference for improved safety during engineering and design. [ABSTRACT FROM AUTHOR]

Objectives: We applied a fully automated pixel-wise post-processing framework to evaluate fully quantitative cardiovascular magnetic resonance myocardial perfusion imaging (CMR-MPI). In addition, we aimed to evaluate the additive value of coronary magnetic resonance angiography (CMRA) to the diagnostic performance of fully automated pixel-wise quantitative CMR-MPI for detecting hemodynamically significant coronary artery disease (CAD). Methods: A total of 109 patients with suspected CAD were prospectively enrolled and underwent stress and rest CMR-MPI, CMRA, invasive coronary angiography (ICA), and fractional flow reserve (FFR). CMRA was acquired between stress and rest CMR-MPI acquisition, without any additional contrast agent. Finally, CMR-MPI quantification was analyzed by a fully automated pixel-wise post-processing framework. Results: Of the 109 patients, 42 patients had hemodynamically significant CAD (FFR ≤ 0.80 or luminal stenosis ≥ 90% on ICA) and 67 patients had hemodynamically non-significant CAD (FFR ˃ 0.80 or luminal stenosis < 30% on ICA) were enrolled. On the per-territory analysis, patients with hemodynamically significant CAD had higher myocardial blood flow (MBF) at rest, lower MBF under stress, and lower myocardial perfusion reserve (MPR) than patients with hemodynamically non-significant CAD (p < 0.001). The area under the receiver operating characteristic curve of MPR (0.93) was significantly larger than those of stress and rest MBF, visual assessment of CMR-MPI, and CMRA (p < 0.05), but similar to that of the integration of CMR-MPI with CMRA (0.90). Conclusions: Fully automated pixel-wise quantitative CMR-MPI can accurately detect hemodynamically significant CAD, but the integration of CMRA obtained between stress and rest CMR-MPI acquisition did not provide significantly additive value. Key Points: • Full quantification of stress and rest cardiovascular magnetic resonance myocardial perfusion imaging can be postprocessed fully automatically, generating pixel-wise myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) maps. • Fully quantitative MPR provided higher diagnostic performance for detecting hemodynamically significant coronary artery disease, compared with stress and rest MBF, qualitative assessment, and coronary magnetic resonance angiography (CMRA). • The integration of CMRA and MPR did not significantly improve the diagnostic performance of MPR alone. [ABSTRACT FROM AUTHOR]

Objective: To identify specific Chinese medicines (CMs) that may benefit patients with gastroesophageal reflux disease (GERD), and explore the action mechanism. Methods: Domestic and foreign literature on the treatment of GERD with CMs was searched and selected from China National Knowledge Infrastructure, China Science and Technology Journal Database, Wanfang Database, and PubMed from October 1, 2011 to October 1, 2021. Data from all eligible articles were extracted to establish the database of CMs for GERD. Apriori algorithm of data mining techniques was used to analyze the rules of herbs selection and core Chinese medicine formulas were identified. A system pharmacology approach was used to explore the action mechanism of these medicines. Results: A total of 278 prescriptions for GERD were analyzed, including 192 CMs. Results of Apriori algorithm indicated that Evodiae Fructus and Coptidis Rhizoma were the highest confidence combination. A total of 32 active ingredients and 66 targets were screened for the treatment of GERD. Enrichment analysis showed that the mechanisms of action mainly involved pathways in cancer, fluid shear stress and atherosclerosis, advanced glycation end product (AGE), the receptor for AGE signaling pathway in diabetic complications, bladder cancer, and rheumatoid arthritis. Conclusion: Evodiae Fructus and Coptidis Rhizoma are the core drugs in the treatment of GERD and the potential mechanism of action of these medicines includes potential target and pathways. [ABSTRACT FROM AUTHOR]

Naturally occurring radium (223Ra, 224Ra, 226Ra, and 228Ra) isotopes have been widely applied as geochemical tracers in marine environments, especially when estimating the submarine groundwater discharge (SGD). In this sense, the influencing factors and transport mechanism of radium isotope activity in aquifers can be key information for SGD estimation. This work evaluates the adsorption/desorption behavior of 224Ra and 226Ra in the solid-liquid phase through a leaching experiment and analysis of field data. The results suggested that radium isotope activity was positively correlated with salinity and grain size, in the case of abundant sediments. Through ion analysis, we found that the ions (Na+, Ca2+, Mg2+, and Ba2+) exchanged with radium isotopes in the process of transport. A 1-D reactive transport model was established to simulate the transport process of radium isotope in aquifers. The model successfully simulated the variation of radium isotope desorption activity with salinity and was subsequently verified in the field. This study contributes to the understanding of the geochemical behavior of radium isotopes in aquifers and provides guidance for selecting a suitable groundwater endmember in SGD estimation. [ABSTRACT FROM AUTHOR]

The solution using built-in beam element method to increase the calculation efficiency of aqueduct pile foundations is studied in this work. The formulations of built-in beam element method based on the normal generalized displacement method of beam element are introduced in this work. Then, the validity of the built-in beam element method is checked by a static problem of a simplified aqueduct model. Furthermore, the solution to increase calculation efficiency by built-in beam element method for aqueduct pile foundations is introduced by studying the features of built-in beam element method and normal generalized displacement method of beam element in models with different grid density and foundation stiffness. Finally, a static problem of an arch aqueduct is solved using the summed solution. The results show that it is feasible to improve efficiency with sufficient accuracy by reasonably selecting the built-in beam element method and normal generalized displacement method in the analysis of aqueduct pile foundation. [ABSTRACT FROM AUTHOR]

Toppling is a typical failure mode of a rock slope. The deformation mechanism and sliding mode of a toppled slope are considerably different from those of conventional slopes. The analysis methods and reinforcement strategies for conventional slopes have some limitations in toppled slopes, especially flexural toppled slopes. In this paper, the right bank slope of the Miaowei hydropower plant was taken as a case study. Based on the qualitative understanding, the method of discrete element analysis is used to “reproduce” the deformation and failure of the slope and analyze the mechanism of deformation and failure. Based on the knowledge gained from the discrete element analysis, closed-loop feedback analysis was carried out to design the reinforcement measures. The analysis confirmed that the excavation in the lower part of the slope and heavy rainfall dominate the formation of sliding failure along the toppling-induced fracture zone. With this understanding, strong anchorage on the middle and lower parts of the slope was planned. Meanwhile, more drainage measures were also designed. The slope was relatively stable during excavation, and the effectiveness of the analysis method and design measures was confirmed. The research results can be used to guide the treatment of flexural toppled slopes. [ABSTRACT FROM AUTHOR]

The Fractional calculus theory is introduced into the Merchant model to study the mechanical characteristics of saturated soils. Laplace transform is applied to the 1D consolidation and the fractional derivative Merchant model constitutive equations of saturated soils. In the transform domain, the analytical solutions of effective stress and settlement are obtained by solving the simultaneous equation. The Crump's method is used to the numerical inversion of Laplace transform, and the semi-analytical solution of the one-dimensional consolidation is obtained. A series of parameters, such as the fractional order, compression modulus, coefficient of viscosity, permeability coefficient and the variation models of groundwater level, are studied. Considering the continuity conditions, the 1D consolidation equation of single-layer saturated soil is generalized to multi-layer soils, and then the influence of different boundaries on several kinds of consolidation behavior was analyzed. [ABSTRACT FROM AUTHOR]

Background: Although fluoroless transseptal puncture (TSP) guided by intracardiac echocardiography (ICE) has been used for many years, there are no reports of an accurate site-specific method for TSP in detail, especially about the safety and efficiency of the method. This study aimed to compare the efficacy and safety of TSP guided by three-dimensional ICE using a fluoroless site-specific method with that of the conventional fluoroless method in patients with atrial fibrillation (AF). Methods: This prospective study included 60 patients with AF scheduled for radiofrequency ablation who were assigned to undergo modified fluoroless site-specific TSP (SS-ICE group, n = 30) or conventional fluoroless TSP (C-ICE group, n = 30). TSP was guided by three-dimensional ICE in both study groups. Results: All fluoroless TSP were performed successfully in both groups. There were no significant differences in patient characteristics, Pre-TSP time (11.3 ± 1.7 min vs. 11.1 ± 1.6 min, P = 0.822) and TSP time (3.4 ± 0.9 min vs. 3.5 ± 1.1 min, P = 0.772) between the SS-ICE group and the C-ICE group. The distance between the actual traversing point and the presetting point in the fossa ovalis was less than 5 mm in 87% of patients (26/30, 3.1 ± 1.2 mm) in the SS-ICE group. There were no TSP-related complications in either group. Conclusion: SS-ICE method is a simple, safe, and effective approach for fluoroless site-specific TSP. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: Immune checkpoint inhibitor (ICI)-associated myocarditis is a potentially fatal complication. Sparse published researches evaluated the prognostic value of cardiovascular magnetic resonance feature tracking (CMR-FT) for ICI-associated myocarditis.Methods: In the single-center retrospective study, 52 patients with ICI-associated myocarditis and CMR were included from August 2018 to July 2021. The ICI-associated myocarditis was diagnosed by using the clinical criteria of the European Society of Cardiology guidelines. Major adverse cardiovascular events (MACE) were comprised of cardiovascular death, cardiogenic shock, cardiac arrest, and complete heart block.Results: During a median follow-up of 171 days, 14 (27%) patients developed MACE. For patients with MACE, the global circumferential strain (GCS), global radial strain (GRS), global longitudinal strain (GLS), and left ventricular ejection fraction (LVEF) were significantly worse and native T1 values and late gadolinium enhancement (LGE) extent were significantly increased, compared with patients without MACE (p < 0.05). The GLS remained the independent factor associated with a higher risk of MACE (hazard ratio (HR): 2.115; 95% confidence interval (CI): 1.379-3.246; p = 0.001) when adjusting for LVEF, LGE extent, age, sex, body mass index, steroid treatment, and prior cardiotoxic chemotherapy or radiation. After adjustment for LVEF, the GLS remained the independent risk factor associated with a higher rate of MACE among patients with a preserved LVEF (HR: 1.358; 95% CI: 1.007-1.830; p = 0.045).Conclusions: GLS could provide independent prognostic value over GCS, GRS, traditional CMR features, and clinical features in patients with ICI-associated myocarditis.Key Points: • The global circumferential strain (GCS), global radial strain (GRS), and global longitudinal strain (GLS) by cardiovascular magnetic resonance feature tracking were significantly impaired in patients with an immune checkpoint inhibitor (ICI)-associated myocarditis. • GLS was still significantly impaired in patients with preserved left ventricular ejection fraction. • The worse GLS was an independent risk factor over GCS, GRS, traditional CMR features, and clinical features for predicting major adverse cardiovascular events in patients with ICI-associated myocarditis. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Building connections between different data sets is a fundamental task in machine learning and related application community. With proper manifold alignment, the correspondences between data sets will assist us with comprehensive study of data processes and analyses. Despite the several progresses in semi-supervised and unsupervised scenarios, potent manifold alignment methods in generalized and realistic circumstances remain in absence. Besides, theretofore unsupervised algorithms seldom prove themselves mathematically. In this paper, we devise an efficient method to properly solve the unsupervised manifold alignment problem and denominate it as extending generalized unsupervised manifold alignment (EGUMA) method. More specifically, an explicit relaxed integer programming method is adopted to solve the unsupervised manifold alignment problem, which reconciles three factors covering the updated local structure matching, the the feature comparability and geometric preservation. An additional effort is retained on extending the Frank Wolfe algorithm to tacking our optimization problem. Besides our previous endeavors we adopt a new strategy for neighborhood discovery in the manifolds. The main advantages over previous methods accommodate (1) simultaneous alignment and discovery of manifolds; (2) complete unsupervised learning structure without any prerequisite correspondence; (3) more concise local geometry for the embedding space; (4) efficient alternative optimization; (5) strict mathematical analysis on the convergence and efficiency issues. Experiments on real-world applications verify the high accuracy and efficiency of our proposed method. [ABSTRACT FROM AUTHOR]

Point cloud analysis becomes a fundamental but challenging problem in the field of 3D scene understanding. To deal with unstructured and unordered point clouds in the embedded 3D space, we propose a novel direction-induced convolution (DIConv) to obtain the hierarchical representations of point clouds and then boost the performance of point cloud analysis. Specifically, we first construct a direction set as the basis of spatial direction information, where its entries can denote these latent direction components of 3D points. For each neighbor point, we can project its direction information into the constructed direction set for achieving an array of direction-dependent weights, then transform its features into the canonical ordered direction set space. After that, the standard image-like convolution can be leveraged to encode the unordered neighborhood regions of point cloud data. We further develop a residual DIConv (Res_DIConv) module and a farthest point sampling residual DIConv (FPS_Res_DIConv) module for jointly capturing the hierarchical features of input point clouds. By alternately stacking Res_DIConv modules and FPS_Res_DIConv modules, a direction-induced convolution network (DICNet) can be built to perform point cloud analysis in an end-to-end fashion. Comprehensive experiments on three benchmark datasets (including ModelNet40, ShapeNet Part, and S3DIS) demonstrate that the proposed DIConv method achieves encouraging performance on both point cloud classification and semantic segmentation tasks. [ABSTRACT FROM AUTHOR]

This study presents a numerical investigation of the shear strength and deformation behaviors of sand-clay interfaces through the distinct element method (DEM). Numerical direct shearing modeling was carried out in PFC2D (particle flow code), considering the effects of the interface geometry, stiffness ratio, friction coefficient, and soil properties. Results indicate that the interface shear strength is greatly mannered by the sample strength and loading conditions. Shear stress curves of samples with smooth interfaces, general stiffness ratio and friction coefficient feature softening behavior that experience peak strengths. The deformation is intensely localized in a narrow shear zone which is below the mid-height of samples. The sample with a sawtooth interface has lower shear strength but more coordination number. With the increase of stiffness ratio, the internal friction angle becomes smaller, and the force chain distribution becomes more uniform. Furthermore, there is an infinitesimally impact from the friction coefficient on the interface shear strength. However, the mesoscopic sliding fraction is greatly affected by the particle friction coefficient. When the bond strength is extremely large, the force chain exhibits uniform dense distribution with central symmetry along the diagonal, corresponding to more coordination number. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The tradeoff between the strength and the fracture elongation in the high-strength Cu–Ni–Si alloy became a hot research topic recently. Cu–Ni–Si–(Ti) alloys were fabricated in a vacuum induction melting furnace to study the effects of titanium on the microstructure and mechanical properties of Cu–Ni–Si alloys with different thermo-mechanical treatments. After homogenization at 900 °C for 4 h, hot-rolled by 80%, solution treatment at 970 °C for 2 h, cold-rolled by 50%, and finally aged at 450 °C for 180 min, the studied Cu–10Ni–Si–2Ti alloy achieved the hardness of HV 252.4, electrical conductivity of 23.6% IACS, tensile strength of 764.4 MPa, yield strength of 622.26 MPa, fracture elongation of 10.4%, and strength-elongation product of 7.95 GPa%, which are less than those of the studied Cu–10Ni–2Si alloy. The addition of Ti contributed to refining the microstructure, suppressing the decreasing trend in mechanical properties after peak hardening, and arousing a primary substructure strengthening mechanism rather than the precipitation strengthening in Cu–Ni–Si alloys. These findings provide essential understandings of the effects of the Ti on Cu–Ni–Si system alloys, and the designed Cu–Ni–Si alloys with high-strength and fracture elongation could fulfill some requirements of the electronic and electrical industry. [ABSTRACT FROM AUTHOR]

Controlling the corrosion rate is critical for practical applications of Mg-based alloys. In this work, we constructed a protective coating of hybrid polycaprolactone (H-PCL)/indocyanine green (ICG) on AZ31 Mg alloy, whose degradation rate was controlled by 808-nm near-infrared (NIR) light irradiation. The corrosion behaviors of H-PCL/ICG coated Mg alloys were systematically investigated by potentiodynamic polarization tests, electrochemical impedance spectroscopy (EIS) and hydrogen evolution experiments. The results disclosed that the H-PCL/ICG composite coating could effectively protect Mg alloy from corroding without NIR light irradiation. In contrast, under 808-nm NIR light irradiation, the corrosion resistance of this composite coating was decreased significantly, i.e., the corrosion current density (icorr) increased from (8.81 ± 1.068) × 10−8 to (1.22 ± 0.545) × 10−6 A·cm−2. This is because the component of ICG in the coating was excited to produce heat locally, which triggered the glass transition temperature (Tg) of H-PCL in the coating, resulting in the motion of the molecular chain segment. Consequently, the electrolytes penetrated the coating and corroded the Mg substrate. In vitro biological experiment indicated that the synthesized coating exhibited good cytocompatibility. Hence, these findings will provide a new strategy for designing novel photoresponsive coatings to remotely adjust the degradation rate of biodegradable metals for biomedical applications. [ABSTRACT FROM AUTHOR]

2 The schematic and simplified flowchart of the cyclic shear loading test device Note, to improve the accuracy for cyclic shearing, there are two separate shear servo valves, one for each shear jack. 1) specialized in cyclic shear loading for rock joints was developed, and tested on artificial joint models under conventional monotonic shear test, and cyclic shear tests with simple and complex stress path. 4a were obtained by setting the stop target as: 2 mm of shear displacement under 0.5 MPa of normal stress, then - 3 mm of shear displacement under 1 MPa of normal stress, followed by 4 mm under 1.5 MPa, ..., until 8 mm of shear displacement at 4 MPa of normal stress was reached. Keywords: Rock joint; Direct shear; Cyclic shear; Shear apparatus EN Rock joint Direct shear Cyclic shear Shear apparatus 4321 4327 7 08/06/21 20210801 NES 210801 Introduction The mechanical behavior of rock joint has always been an important issue in the field of geotechnical practice. [Extracted from the article]

In order to enhance the sensing performance of isopropanol (IPA) vapor at room temperature (RT), a conducting polymer of polypyrrole (PPy) was employed to modify the ordered silicon nanowires (SiNWs). The loose structure of SiNWs which has the advantage of forming the structure of SiNWs uniformly coated by PPy was obtained via a dual-metal-assisted chemical etching (MACE) process. Vapor chemical polymerization of the pyrrole monomer (Py) was employed to prepare ultrathin PPy film uniformly functionalized SiNWs array, i.e., PPy@SiNWs. The results exhibit that an ultrathin PPy shell with thickness of 10 nm is wrapped on the surface of a loose SiNWs array forming perfect core-shell structure. Comparative investigations on the IPA-sensing properties of the PPy@SiNWs, SiNWs and PPy were carried out at RT. It shows that the as-formed PPy@SiNW sensor exhibits about a sevenfold response enhancement to 100 ppm IPA gas compared to the bare SiNWs. Moreover, the PPy@SiNW shows an acceptable stability, with a response attenuation of 8.9% observed within 33 days. The gas sensing results confirm that the PPy decoration can improve the sensing response and stability of the SiNW-based sensor. [ABSTRACT FROM AUTHOR]

An aerobic, Gram-stain-negative, straight or curved rods and dimorphic prosthecate bacterium designated as strain LZ-16-1T was isolated from phycosphere microbiota of routinely laboratory-cultured and highly-toxic marine dinoflagellate Alexandrium catenella LZT09. Strain LZ-16-1T produces active bioflocculanting exopolysaccharides (EPS). Cells were dimorphic with non-motile prostheca, or non-stalked and motile by a single polar flagellum. Growth occurred at 10–40 °C, pH 5–9 and 1–8% (w/v) NaCl, with optimum growth at 25 °C, pH 7–8 in the presence of 2–4% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain LZ-16-1T was affiliated to the genus Maricaulis, and closely related to M. parjimensis MCS 25T (99.5%) and M. virginensis VC-5T (99.0%). However, based on genome sequencing and phylogenomic calculations, the average nucleotide identity (ANI) and digtal DNA-DNA genome hybridization (dDDH) values between strains LZ-16-1T and its closest relative, M. parjimensis MCS 25T were only 85.0 and 20.9%, respectively. The dominant fatty acids of strain LZ-16-1T were summed feature 8, C16:0, C17:0, C18:0, C18:1ω9c and summed feature 9. Major polar lipids were sulfoquinovosyl diacylglycerol, six glycolipids, one unidentified phospholipid and one unidentified polar lipid. The predominant isoprenoid quinone was Q-10. The DNA G + C content calculated from the genome was 63.6 mol%. Physiological and chemotaxonomic characterizations further confirmed the distinctiveness of strain LZ-16-1T from other Maricaulis members. Thus, strain LZ-16-1T represents a novel species of the genus Maricaulis, for which the name Maricaulis alexandrii sp. nov. (type strain LZ-16-1T = KCTC 72194T = CCTCC AB 2019006T) is proposed. [ABSTRACT FROM AUTHOR]

In this work, amorphous Zr55Al10Ni5Cu30 alloy thin film was prepared on D36 steel substrate by magnetron sputtering method. The film was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), hardness tester and nano indentation. Corrosion behavior of the film was investigated in 3.5% NaCl aqueous solutions by an electrochemical method. At room temperature, the amorphous alloy film was formed completely after sputtering for 5 h. The surface morphology of the amorphous alloy film was uniform and smooth. Formation of the amorphous alloy film improved the microhardness and corrosion resistance of the D36 substrate. The amorphous alloy film (prepared at room temperature for 5 h) exhibited good adhesion strength with the substrate. The as-sputtered sample exhibited a crevice corrosion trend when the sputtering time was too short (1 h) or too long (10 h). [ABSTRACT FROM AUTHOR]

Recently, the two-dimensional heterostructure is a research hot spot of semiconductor materials, and it has wide application prospects in electronic devices and photocatalysis. In this work, we constructed novel graphene-GaN-graphene (G-GaN-G) sandwich heterostructure, and the electronic and optical properties have been theoretically investigated based on the first principles calculations. The computation results indicate that the heterostructure is most stable when interlayer distance d0 is 3.189 Å, and electronic and optical properties of intrinsic GaN and graphene are well preserved. In addition, the effect of vertical and biaxial strain on the G-GaN-G heterostructure is also investigated, we find that strain can effectively regulate the electronic and optical properties. Therefore, the electronic and optical properties of G-GaN-G can be tuned by applying different levels of strain to meet the needs of devices. This study results reveal that the G-GaN-G sandwich heterostructure can be hopefully applied to ultraviolet photodetectors and optoelectronic devices. [ABSTRACT FROM AUTHOR]

The Ti51.44Zr16.26Cu30Sn2.3 (at%) amorphous filler alloy in a ribbon form was prepared by melt spinning. The Ti–6Al–4V alloy was brazed in vacuum furnace by using the Ti51.44Zr16.26Cu30Sn2.3 amorphous filler alloy. The effects of brazing temperature and holding time on the interfacial microstructure and mechanical properties of the Ti–6Al–4V brazed joints were investigated. The brazed joints are composed of α-Ti, β-Ti, and (Ti, Zr)2Cu phases. The shear strength of the joints increases with brazing temperature increasing from 1153 to 1193 K and holding time from 10 to 15 min, while decreases with brazing temperature and time further increasing. Low temperature brazing results in the formation of microcracks and voids in the seams, which are harmful for the shear strength of the joints. In the joint brazed at 1193 K for 15 min, a fine α + β Widmanstätten structure beneficial to the mechanical property is formed, and the joint exhibits relatively high joint strength of 180 MPa. [ABSTRACT FROM AUTHOR]

During the study into the microbial biodiversity and bioactivity of the Microcystis phycosphere, a new yellow-pigmented, non-motile, rod-shaped bacterium containing polyhydroxybutyrate granules designated as strain Z10-6T was isolated from highly-toxic Microcystis aeruginosa Kützing M.TN-2. The new isolate produces active bioflocculating exopolysaccharides. Phylogenetic analysis based on 16S rRNA gene sequences indicated strain Z10-6T belongs to the genus Sphingopyxis with highest similarity to Sphingopyxis solisilvae R366T (98.86%), and the similarity to other Sphingopyxis members was less than 98.65%. However, both low values obtained by phylogenomic calculation of average nucleotide identity (ANI, 85.5%) and digital DNA-DNA hybridization (dDDH, 29.8%) separated the new species from its closest relative. The main polar lipids were sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified glycolipid and one unidentified aminophospholipid. The predominant fatty acids were summed feature 8, C17:1ω6c, summed feature 3, C16:0, C18:1ω7c 11-methyl and C14:0 2-OH. The respiratory quinone was ubiqunone-10, with spermidine as the major polyamine. The genomic DNA G + C content was 64.8 mol%. Several biosynthesis pathways encoding for potential new bacterial bioactive metabolites were found in the genome of strain Z10-6T. The polyphasic analyses clearly distinguished strain Z10-6T from its closest phylogenetic neighbors. Thus, it represents a novel species of the genus Sphingopyxis, for which the name Sphingopyxis microcysteis sp. nov. is proposed. The type strain is Z10-6T (= CCTCC AB2017276T = KCTC 62492T). [ABSTRACT FROM AUTHOR]

Water splitting is an environment friendly and efficient way to produce hydrogen. Highly efficient and low-cost non-noble metal catalysts play an important role in hydrogen evolution reaction (HER). Dealloying is a simple method to prepare three-dimensional self-supporting nanoporous materials without conductive supports and binders. In this work, we prepared self-supporting nanoporous CoBP electrocatalyst by dealloying method. The influence of the synergistic effect of nonmetallic elements on catalytic activity was investigated. The synergistic electronic effect of Co, B and P atoms on the surface optimizes the H atoms desorption and results in superior HER activity. The bi-continuous structure of nanoporous CoBP provides more active area and favors of electron and electrolyte transfer. The nanoporous CoBP with the B/P atomic ratio of 1/3 exhibits low overpotential of 42 mV at 10 mA·cm−2, small Tafel slope of 39.8 mV·dec−1 and good long-term stability with no performance decrease for 20 h in alkaline solution. [ABSTRACT FROM AUTHOR]

To investigate the effect of the loading rate on the tensile strength of rock material and the morphology of the resulting split fracture surfaces, three types of rock specimens, namely, granite, basalt and limestone, were collected and tested with Brazilian testing under different loading rates. The tensile strength was measured, and the effect of the loading rate on the tensile strength of the rock material was studied. Digital terrain map models of the split fracture surface were obtained with an optical 3D scanning technique, and the effects of the loading rate on the geometry and morphology of the fracture surface were studied. The influence of the loading rate and tensile strength on the roughness was studied quantitatively by calculating the roughness indices of a fracture surface for all three kinds of rock. The research results show that the rock tensile strength increases with the loading rate. A linear relationship was established in double-logarithmic coordinates to describe the relationship between the tensile strength and the loading rate. Four different roughness indices were used to describe the morphology of the split fracture surface. The analysis results show that the magnitudes of all the roughness indices increase with the loading rate. Additionally, the roughness indices for all three types of rock linearly increase with the tensile strength. This linear trend indicates that it is possible to utilize fracture surface roughness indices to estimate rock tensile strength. The current study may motivate further research on the relationship between the morphology indices of rock fractures and mechanical parameters of the rock. [ABSTRACT FROM AUTHOR]

A precise and noninvasive method for the size and shape measurement of gold nanorods (GNRs) has been proposed based on depolarized dynamic light scattering (DDLS). A home-made DDLS apparatus has been established. By applying depolarized optical path with precise alignment method, the signal-to-noise ratio (SNR) of this apparatus is highly improved. GNRs with three different diameter and length has been precisely measured by using DDLS method as well as scanning electron microscopy (SEM). The thickness of adsorption layer of cetyltrimethylammonium bromide (CTAB) in solution has been taken into consideration. Results show that size measurement of GNRs by using DDLS method agrees very well with that by using SEM. In addition, it is shown that the extinction spectroscopy strongly limited the application of DDLS method by affecting the effective scattering light intensity. Proper laser wavelength should be chosen before the application of this method. [ABSTRACT FROM AUTHOR]

Safe construction and operation of tunnels in high seismic risk regions require special aseismic design. A possible solution to this issue is to consider the earthquake damage that a tunnel may suffer beforehand in the process of engineering rock mass classification during the geotechnical investigation phase. Then, the tunnel support system is designed with this modified classification result. To verify this hypothesis, this work investigates the Chinese engineering rock mass classification system, the basic quality (BQ) rating system, considering seismic effects. The main contribution of the current work is to quantitatively modify the rock mass intactness index Kv in the BQ system considering the potential earthquake damage under various levels of design peak ground acceleration. The procedure to obtain the rock mass basic quality index considering the design peak ground acceleration is proposed and verified with real field data from the 2008 Wenchuan earthquake. This approach is a promising enhancement of the empirical methods for considering the seismic effects for tunnels that require special design against possible earthquake impacts. [ABSTRACT FROM AUTHOR]

Maize is one of the most vital staple crops worldwide. G proteins modulate plentiful signaling pathways, and G protein-coupled receptor-type G proteins (GPCRs) are highly conserved membrane proteins in plants. However, researches on maize G proteins and GPCRs are scarce. In this study, we identified three novel GPCR-Type G Protein (GTG) genes from chromosome 10 (Chr 10) in maize, designated as ZmCOLD1-10A, ZmCOLD1-10B and ZmCOLD1-10C. Their amino acid sequences had high similarity to TaCOLD1 from wheat and OsCOLD1 from rice. They contained the basic characteristics of GTG/COLD1 proteins, including GPCR-like topology, the conserved hydrophilic loop (HL) domain, DUF3735 (domain of unknown function 3735) domain, GTPase-activating domain, and ATP/GTP-binding domain. Subcellular localization analyses of ZmCOLD1 proteins suggested that ZmCOLD1 proteins localized on plasma membrane (PM) and endoplasmic reticulum (ER). Furthermore, amino acid sequence alignment verified the conservation of the key 187th amino acid T in maize and other wild maize-relative species. Evolutionary relationship among plants GTG/COLD1 proteins family displayed strong group-specificity. Expression analysis indicated that ZmCOLD1-10A was cold-induced and inhibited by light. Together, these results suggested that ZmCOLD1 genes had potential value to improve cold tolerance and to contribute crops growth and molecular breeding. [ABSTRACT FROM AUTHOR]

A large number of salt caverns by solution mining are abandoned widely. After reasonable reformation, some of these caverns are expected to store energies, such as petroleum, natural gas, and compressed air energy. Different from other countries, salt formations of China are mainly bedded with lower thickness. In order to improve the mining efficiency of bedded salt formations, solution mining with double-well convection is widely adopted, which brings more horizontal caverns with larger dimensions and also larger roofs. When these horizontal caverns are transformed into underground energy storage, the layered roofs are easily suffered from unbalanced deformation and failure, and then become the channels of oil or gas leakage. Therefore, a series of theoretical analysis and numerical simulation were carried out to reveal the failure mechanism and stability of the bedded roof, and then some meaningful conclusions are acquired. Firstly, in the overlying strata, the argillaceous anhydrite layer is the key roof in the selection of the abandoned horizontal cavern for energy storage. Secondly, according to plate theory, the invalid of the bedded key roof needs to be treated into failure and instability respectively. Thirdly, the analysis on the vertical and horizontal stress in the key roof shows that it does experience a second type of instability. Finally, in order to maintain the stability of bedded key roof, the main influence factors require careful and comprehensive consideration, including the length of the long side, the thickness of the protective salt layer, and the internal pressure. [ABSTRACT FROM AUTHOR]

Based on the calculation using first-principles, we discussed adjustment for electronic properties of the GaN/graphene/WS2 trilayer vdW heterostructure by doping and biaxial strain. Mg or Se doping can regulate the band gap of the GaN/graphene/WS2 trilayer vdW heterostructure and achieve p-type or n-type dopant in graphene and the trilayer heterostructure system. Band gap decreases with the increase in positive strain, and a p-type Schottky barrier is always maintained. As the negative strain increases, the band gap reaches its maximum at ε = − 3% and then gradually decreases. And after |ε| ≥ | − 5|%, it changes to an indirect band gap. When |ε| ≥ | − 7|%, the Schottky contact type changes from p-type to n-type. Electrons are transferred from GaN layer to graphene and WS2 layer, and transfer increases with the increase in strain from negative to positive. More electrons are transferred to WS2 with positive strain, and more electrons are transferred to graphene with negative strain. The results will provide valuable information for the design of trilayer Schottky devices. [ABSTRACT FROM AUTHOR]

The problem of the settlement and deformation of soft clay is becoming more and more prominent under the subway vibration loading. Due to the complexity of the construction environment in the soft soil areas, the artificial freezing method is often used to reinforce the soil, and sometimes it is also subjected to twice freezing. The Shanghai subway line crosses vertically and horizontally. The deepest excavation depth reaches 33.1 m, so the construction of the subway tunnel will develop to a deeper stratum. In this paper, the GDS dynamic triaxial tests were conducted to study the accumulated deformation of the gray silty clay of layer no.8 in Shanghai, 60 m in depth. Considering the influence of vibration time, frequencies, freezing temperatures, and freezing-thawing cycles, the axial strain of the deep silty clay before and after freezing-thawing was analyzed. The results show that the strain of the soil subjected to one freezing-thawing cycle and two freezing-thawing cycles increases by 39.6% and 72.8% comparing with the unfrozen soil, respectively. With the increase of vibration time, the rates of increasing of the axial strain gradually decrease. The higher the frequency and the lower the freezing temperature, the more deformation produces to the soil. The microstructures of the soil before and after freezing-thawing were obtained by mercury intrusion porosimetry (MIP) tests. There is a bottleneck with the pressure about 100 psi in the mercury intrusion process. Under the same cyclic loading, the lower the freezing temperatures and the more the freezing-thawing cycles, the more the mercury intrusion volume and the cumulative pore area. The most probable pore diameter of the unfrozen soil is about 524 nm smaller than that of the thawing soil, which is about 1050 nm. The pores 10–100 nm in diameter account for a large part. This research is of great guiding significance for the construction of deep subway tunnels. [ABSTRACT FROM AUTHOR]

Shear failures of sand–clay interfaces are frequently encountered in engineering practice. It is of great concern to investigate the shear strength of the sand–clay interfaces. In this work, a series of large-scale direct shear tests have been conducted on the sand–clay interfaces. Considering the influences of the interface roughness, the preloading and the stiffness ratio, the interface shear stresses and the vertical displacements are evaluated and compared under different normal stresses. Results indicate that the interface shear stresses and the vertical displacement of the sand–clay samples are quasi-dependent of normal stresses. The shear stress curves feature hardening characteristics with no peak values followed by softening. Light dilation at the shear beginning followed by continuous contraction show in the vertical displacement curves. The interface shear strength is reduced, and the ultimate vertical displacement increases when the preloading is applied before shearing. Larger stiffness ratio leads to smaller ultimate shear stresses and larger ultimate vertical displacements. The values of the ultimate interface shear stresses and vertical displacements of sand–clay samples are between those of the sand–sand and clay–clay samples. Additionally, the movement pattern of the upper sand particles is observed by particle image velocimetry analysis. [ABSTRACT FROM AUTHOR]

Magnetic minerals in marine sediments are often masked by the primary natural remanent magnetization and material source signals. In order to understand sedimentary environment and sources of sediments in the abyss, we studied 126 samples of five bottom surface cores collected by the Jiaolong Submersible at 4000–7000 m in depth during the third stage of the China's 38th Ocean Voyage. The magnetic properties of the sediments were analyzed using Thermosusceptibility (k-T) curves and Day plot. The results show that the magnetic minerals in the sediments of the Yap Trench are mainly maghemite, and the overall magnetic and soft magnetic properties were strong. The magnetic particles of sediments are dominated by pseudo single domains (PSD) grains. The main source of sediment is locally-derived basalt debris and volcanic debris, and the process of sedimentation is gravity-like flow deposition. [ABSTRACT FROM AUTHOR]

Artificial ground freezing (AGF) technology characterized by good waterproof performance, wide adaptability, minimal pollution, and other advantages has been widely used in the construction of tunnel cross passages buried in the soft soil layers. Based on the in situ monitoring, the temperature field of the freezing wall and the deformation field around a cross passage are studied in this paper. The results show that the descent speed of the soil temperature is large at the beginning and becomes small gradually, and finally tends to be stable. The frozen cylinders are enclosing in the phase transformation stage of water. The closer to the freezing pipes the soil is, the faster the soil temperature drops. The temperature of the soil inside the freezing wall is lower than that of the soil outside the freezing wall. The frost heave capacity at the center of the cross passage is the largest, so is the growth rate of the frost heave. The results can offer a reference to the design and construction of the cross passages buried in the soft soil areas. [ABSTRACT FROM AUTHOR]

Urban land subsidence is influenced by many factors, including building loads, underground water and engineering environment, etc. In this paper, the engineering-environmental effect on the land subsidence was studied through the in-site monitoring and numerical simulation. The remarkable subsidence superimposition effect exists among the high-rise buildings. The land subsidence decreases dramatically with the increasing distance away from buildings. The land subsidence range caused by high-rise building loads is probably 300 m. The surrounding area of the high-rise buildings experience larger land subsidence than the estimated value for the superimposed additional stress. Different levels of groundwater exploitation related to the vertical influence range lead to different land subsidence. The exploitation of the second aquifer is mainly supplied by the surrounding fixed head conditions. Although there is a certain amount of overflow supply, the soil saturation will not change greatly. [ABSTRACT FROM AUTHOR]

It is not widely accepted that the dynamic strain rate experienced by a rock mass during an earthquake is lower than that during a high strain rate scenario such as an explosion or a rock burst. The present study investigated the problem of determining the mechanical properties of rock considering earthquake effects using experimental tests and empirical formulas. First, to obtain the most concentrated frequency band of earthquake energy, a statistical analysis was conducted to obtain the response spectra of ground motion records near the example projects. The mean response spectrum was then fitted with a design response spectrum formula. The most concentrated frequency band of earthquake energy was then determined with the flat segment of the design response spectrum. Based on this frequency range, cyclic loading–unloading testing that simulated the earthquake effect was conducted on rock samples. The strain rate range experienced by rocks during an earthquake was then obtained. This strain rate range is between the quasi-static and intermediate strain rate ranges and is significantly lower than the high strain rate range. Based on this strain rate range, dynamic triaxial compression tests were conducted on igneous rock specimens from the case study areas. It is confirmed that the fit of the dynamic compression test results with the Hoek–Brown (HB) criterion is more accurate than that with the Mohr–Coulomb criterion. The HB strength envelope under static conditions can be used to predict the seismic strength behaviors, requiring an update of only the intercept of the envelope. Thus, the HB strength criterion considering the seismic effect was obtained. Moreover, the seismic modulus of the intact rock can be estimated with the values of the uniaxial compressive strength (UCS) under different strain rates and the modulus ratio, which was found to be independent of the strain rate. Hence, it is practical to estimate the mechanical properties of rock masses in consideration of seismic effects with the seismic HB strength criterion and the Hoek and Diederichs equation based on the UCSs under various strain rates. Ultimately, the rock mechanical properties in consideration of seismic effects were estimated via the proposed approach for the Baihetan hydropower plant project as an example. [ABSTRACT FROM AUTHOR]

We have evaluated the antiproliferative activity of (E)-3-(3,5-difluorophenyl)-1-(2,4,6-trimethoxyphenyl)- prop-2-en-1-one (chalcone 5) against MGC-803 cells. This chalcone analog displayed a potent antiproliferative activity with an IC50 value of 0.23 μM against MGC-803 cells. It could induce apoptosis and regulate the apoptosis-related markers (Bax, Bcl-2, Bcl-xl, and Bid) in a concentration dependent manner. Treatment with NAC almost completely attenuated chalcone-induced cell inhibition and cell apoptosis in MGC-803 cells, indicating that the apoptotic mechanisms were related to ROS generation. Therefore, this chalcone derivative is a new apoptosis inducer for prevention and treatment of gastric cancer. [ABSTRACT FROM AUTHOR]

In this paper, a novel regression model, called graph regularized sparse linear regression (GRSLR), is proposed to deal with EEG emotion recognition problem. GRSLR extends the conventional linear regression method by imposing a graph regularization and a sparse regularization on the transform matrix of linear regression, such that it is able to simultaneously cope with sparse transform matrix learning while preserve the intrinsic manifold of the data samples. To detailed discuss the EEG emotion recognition, we collect a set of 14 subjects EEG emotion data and provide the experiment results on different features. To evaluate the proposed GRSLR model, we conduct experiments on the SEED database and RCLS database. The experimental results show that the proposed algorithm GRSLR is superior to the classic baselines. The RCLS database is made publicly available and other researchers could use it to test their own emotion recognition method. [ABSTRACT FROM AUTHOR]