Surface skyrmions and dual topological Hall effect in antiferromagnetic topological insulator EuCd2_2As2_2

In this work, we synthesized single crystal of EuCd$_2$As$_2$, which exhibits A-type antiferromagnetic (AFM) order with in-plane spin orientation below $T_N$ = 9.5~K.Optical spectroscopy and transport measurements suggest its topological insulator (TI) nature with an insulating gap around 0.1eV. Remarkably, a dual topological Hall resistivity that exhibits same magnitude but opposite signs in the positive to negative and negative to positive magnetic field hysteresis branches emerges below 20~K. With magnetic force microscopy (MFM) images and numerical simulations, we attribute the dual topological Hall effect to the N\'{e}el-type skyrmions stabilized by the interactions between topological surface states and magnetism, and the sign reversal in different hysteresis branches indicates potential coexistence of skyrmions and antiskyrmions. Our work uncovers a unique two-dimensional (2D) magnetism on the surface of intrinsic AFM TI, providing a promising platform for novel topological quantum states and AFM spintronic applications.Comment: 7 pages, 3 figure

SHN: rock image classification and feature visualization using multiple granularity spatial disorder hierarchical residual network

The automated classification of rock images is of paramount importance in geological analysis, as it serves as the foundational criterion for the categorization of rock lithology. Despite recent advancements in leveraging deep learning technologies to enhance the efficiency and precision of image classification, a crucial aspect has been overlooked: these methods face a performance bottleneck when attempting to apply it directly to rock classification methods. To address this limitation, we propose a multiple granularity Spatial disorder Hierarchical residual Network (SHN). This approach involves learning from objects annotated at different levels, thereby facilitating the transfer of hierarchical knowledge across levels. By enabling lower-level classes to inherit pertinent attributes from higher-level superclasses, our method aims to capture the intricate hierarchical relationships among different rock types. Especially, we introduce a multi-granularity spatial disorder module to aid neural networks in discerning discriminative details across various scales. This module enables processed images to exhibit region independence, compelling the network to adeptly identify discriminative local regions at diverse granularity levels and extract pertinent features. Furthermore, in light of the absence of a comprehensive rock dataset, this study amassed 4,227 rock images of diverse compositions from various places, culminating in the creation of a robust rock dataset for classification. Rigorous experimentation on this dataset yielded highly promising results, demonstrating the effectiveness of our proposed method in addressing the challenges of rock image classification

In situ formed Mg(BH4)2 for improving hydrolysis properties of MgH2

The hydrolysis of MgH2 delivers high hydrogen capacity (15.2 wt%), which is very attractive for real-time hydrogen supply. However, the formation of a surface passivation Mg(OH)2 layer and the large excess of H2O required to ensure complete hydrolysis are two key challenges for the MgH2 hydrolysis systems. Now, a low-cost method is reported to synthesize MgH2@Mg(BH4)2 composite via ball-milling MgH2 with cheap and widely available B2O3 (or B(OH)3). By adding small amounts of B2O3, the in-situ formed Mg(BH4)2 could significantly promote the hydrolysis of MgH2. In particular, the MgH2–10 wt% B2O3 composite releases 1330.7 mL·g−1 H2 (close to 80% theoretical hydrogen generation H2) in H2O and 1520.4 mL·g−1 H2 (about 95%) in 0.5 M MgCl2 in 60 min at 26 °C with hydrolysis rate of 736.9 mL·g−1·min−1 and 960.9 mL·g−1·min−1 H2 during the first minute of the hydrolysis, respectively. In addition, the MgCl2 solution allows repeated use by filtering and exhibits high cycle stability (20 cycles), therefore leading to much reduced capacity loss caused by the excess H2O. We show that by introducing B2O3 and recycling the 0.5 M MgCl2 solution, the system hydrogen capacity can approach 5.9 wt%, providing a promising hydrogen generation scheme to supply hydrogen to the fuel cells

Concrete Elastic Modulus Experimental Research Based on Theory of Capillary Tension

The risk of cracking in the early stage is a critical indicator of the performance of concrete structures. Concrete cracked when the tensile stresses caused by deformation under restraint conditions exceeded its tensile strength. This research aims at an accurate prediction of shrinkage cracking of concrete under constraints. Based on the theory of capillary tension under the concrete shrinkage mechanism, the method to test and compute the elastic modulus of a micro-matrix around the capillary, Et, was derived. Shrinkage and porosity determination tests were conducted to obtain the shrinkage values and confining stresses of concrete at different strength grades, different ages and under different restraint conditions, accordingly. Meanwhile, the proposed method of this research was used to obtain Et. The restraint stress given by Et was compared with the experimental result under the corresponding time. The results suggested a positive correlation between the elastic modulus of a micro-matrix around the capillary, Et, precomputed by the theory, and the static elastic modulus, Ec, and that the ratio between the two gradually decreased with the passage of time, which ranged from 2.8 to 3.1

Transcriptome-wide transmission disequilibrium analysis identifies novel risk genes for autism spectrum disorder.

Recent advances in consortium-scale genome-wide association studies (GWAS) have highlighted the involvement of common genetic variants in autism spectrum disorder (ASD), but our understanding of their etiologic roles, especially the interplay with rare variants, is incomplete. In this work, we introduce an analytical framework to quantify the transmission disequilibrium of genetically regulated gene expression from parents to offspring. We applied this framework to conduct a transcriptome-wide association study (TWAS) on 7,805 ASD proband-parent trios, and replicated our findings using 35,740 independent samples. We identified 31 associations at the transcriptome-wide significance level. In particular, we identified POU3F2 (p = 2.1E-7), a transcription factor mainly expressed in developmental brain. Gene targets regulated by POU3F2 showed a 2.7-fold enrichment for known ASD genes (p = 2.0E-5) and a 2.7-fold enrichment for loss-of-function de novo mutations in ASD probands (p = 7.1E-5). These results provide a novel connection between rare and common variants, whereby ASD genes affected by very rare mutations are regulated by an unlinked transcription factor affected by common genetic variations

Semantic web portal: a platform for better browsing and visualizing semantic data

Abstract. One of the main shortcomings of Semantic Web technologies is that there are few user-friendly ways for displaying, browsing and querying semantic data. In fact, the lack of effective interfaces for end users significantly hinders further adoption of the Semantic Web. In this paper, we propose the Semantic Web Portal (SWP) as a light-weight platform that unifies off-the-shelf Semantic Web tools helping domain users organize, browse and visualize relevant semantic data in a meaningful manner. The proposed SWP has been demonstrated, tested and evaluated in several different use cases, such as a middle-sized research group portal, a government dataset catalog portal, a patient health center portal and a Linked Open Data portal for bio-chemical data. SWP can be easily deployed into any middle-sized domain and is also useful to display and visualize Linked Open Data bubbles

MgH₂@Mg(BH₄)₂ Core–Shell-like Nanostructures: Synthesis, Hydrolysis Performance, and Promotion Mechanism

The hydrolysis of hydrides, represented by MgH2, delivers substantial capacity and presents an appealing prospect for an on-site hydrogen supply. However, the sluggish hydrolysis kinetics and low hydrogen yield of MgH2 caused by the formation of a passivation Mg(OH)2 layer hinder its practical application. Herein, we present a dual strategy encompassing microstructural design and compounding, leading to the successful synthesis of a core–shell-like nanostructured MgH2@Mg(BH4)2 composite, which demonstrates excellent hydrolysis performance. Specifically, the optimal composite with a low Ea of 9.05 kJ mol–1 releases 2027.7 mL g–1 H2 in 60 min, and its hydrolysis rate escalates to 1356.7 mL g–1 min–1 H2 during the first minute at room temperature. The nanocoating Mg(BH4)2 plays a key role in enhancing the hydrolysis kinetics through the release of heat and the formation of local concentration of Mg2+ field after its hydrolysis. This work offers an innovative concept for the design of hydrolysis materials