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Nanoindentation has been widely utilized for measuring mechanical properties at small scales over the past three decades. Indentation size effect (ISE) is a crucial phenomenon in nanoindentation testing of crystalline materials, which is usually manifested as an increase of hardness with a decrease of indent size. Tremendous efforts have been made to understand ISE with the aim of eliminating its influence on determining the intrinsic mechanical properties. More importantly, ISE is a key phenomenon for exploring the unique deformation mechanisms of crystalline materials at the nanoscale. We critically review the experimental observations of ISE in crystalline materials, focusing on the influences of the indenter geometry and crystal structure. In addition, the mechanistic models proposed for ISE as well as recent findings by numerical simulations are also examined in detail to explore the origins of ISE and identify the unsolved challenges.

The Sigara lateralis (Leach, 1817) is a small aquatic insect belonging to the family Corixidae. The study aims to reveal the genomic data of the mitochondrial genome of S. lateralis. The length of its circular mitochondrial genome is 15,725 bp long with an A + T bias (75.96%). The mitogenome comprises 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNA genes, and two rRNA genes. The phylogenetic analyses showed that the S. lateralis is the closest to S. septemlineata. These findings will help the conservation of Corixidae from the perspective of genetic evolution.

Objective The millisecond-level precision of NTP (network time protocol) in train communication networks has increasingly failed to meet the requirements of high traffic and deterministic transmission. Meanwhile, existing research is limited to applying the PTP (precision time protocol) to train communication scenarios, lacking research on time synchronization in time-sensitive networks within train communication networks. Therefore, it is necessary to conduct relevant analysis. Method Firstly, based on the current research status of time synchronization in train communication networks, the deviation and delay in train communication networks are analyzed according to time-sensitive network synchronization protocols. Secondly, redundancy mechanis for clock service source failures and jumps are proposed. Finally, the effectiveness of the redundancy mechanism is verified through simulation of the time synchronization process. Result & Conclusion Time-sensitive networks are well suited for time synchronization of clock service sources in train communication networks, and their redundancy mechanisms effectively mitigate synchronization errors caused by clock service source failures and jumps.

Objective TCN (train communication networks) has complex topologies and requires high real-time transmission capabilities. Currently, train data transmission mainly relies on TRDP (train real-time data protocol) for carriage, while there are issues of network latency uncertainty. TSN is thus adopted to ensure bounded latency for data transmission, addressing the aforementioned issues faced by TCN. Method A method called TTAM (TRDP and TSN adaptive method) is proposed to achieve protocol conversion between TRDP and TSN, ensuring data transmission in the network. Result & Conclusion Through the establishment of a TSN testbed, the functionality and performance of TSN networks (IEEE 802.1 AS and IEEE 802.1 Qbv) are tested, validating the effectiveness of TTAM in TSN technology application.

This paper presents an innovative numerical modeling framework capable of generating highly realistic 3D mesoscale multi-phase concrete models with unprecedented efficiency and accuracy. Addressing a significant wide range in aggregate volume fraction (0 to 80%) and featuring rapid model generation capabilities, our framework marks a breakthrough in reducing computational time—achieving simulations of 1 million elements within mere 30 s on readily available hardware. By analyzing randomly generated concrete samples across varying compositions, our algorithm can provide deep mesoscopic insights into their compressive properties, validated against a wide array of experimental results. Additionally, our comprehensive analytical model sheds light on the intricate roles of aggregate volume fraction and porosity, enhancing understanding of the meso-scale compressive behavior. We also make the source code available on GitHub, offering a valuable tool for the engineering and research community to optimize concrete material design and performance.

Size effect of the nickel-based single crystal superalloy DD6 is investigated in this study by performing nanoindentation experiments and finite element (FE) simulations by emphasizing the strain rate effect. An analytical method is proposed to identify whether a material has the indentation size effect (ISE) based on incremental formulations of the indentation strain rate. By taking ISE as a critical factor, the contact area is further described by considering the curvature radius of non-ideal indenters due to wear issues in practice. In order to emphasize the strain rate effect during indentations, the material parameters dominating mechanical properties are adopted from the strain rate dependent Johnson–Cook model, particular for the nickel-based single crystal superalloy. Consequently, the dimensional ISE analysis is performed by proposing a theoretical framework to establish the relationship among the indentation strain rate, the indenter tip curvature radius and the applied load–penetration depth (P–h) curve for characterizing nanoindentation responses. By identifying the indenter curvature radii and loading time as the important external factors of hardness measurement, FE simulations are validated to achieve good agreement with experimental data. The validated FE predictions are reliably employed to calibrate the dimensionless model of hardness with different indenter curvature radii and loading rates. In the proposed form of the dimensional hardness model, it is found that the indenter curvature radius can be perfectly independent of the material constitutive properties and loading rates. It reveals the potential and advantageous determination of characteristic length of materials by using nanoindentation.

Introduction: Human topoisomerase 1 (TOP1) is an important target of various anticancer compounds. The design and discovery of inhibitors targeting TOP1 are of great significance for the development of anticancer drugs. Evodiamine and thieno [2,3-d] pyridine hybrids show potential antitumor activity. Herein, the anti-gastric cancer activities of these hybrids were investigated.Methods: The inhibitory effects of different concentrations of ten evodiamine derivatives on the gastric cancer cell line SGC-7901 were assessed using a methyl thiazolyl tetrazolium assay. Compounds EVO-1 and EVO-6 strongly inhibited gastric cancer cell proliferation, with inhibition rates of 81.17% ± 5.08% and 80.92% ± 2.75%, respectively. To discover the relationship between the structure and activity of these two derivatives, density functional theory was used to investigate their optimized geometries, natural population charges, frontier molecular orbitals, and molecular electrostatic potentials. To clarify their anti-gastric cancer mechanisms, molecular docking, molecular dynamics simulations, and binding free energy calculations were performed against TOP1.Results: The results demonstrated that these compounds could intercalate into the cleaved DNA-binding site to form a TOP1–DNA–ligand ternary complex, and the ligand remained secure at the cleaved DNA-binding site to form a stable ternary complex. As the binding free energy of compound EVO-1 with TOP1 (−38.33 kcal·mol−1) was lower than that of compound EVO-6 (−33.25 kcal·mol−1), compound EVO-1 could be a more potent anti-gastric cancer agent than compound EVO-6.Discussion: Thus, compound EVO-1 could be a promising anti-gastric cancer drug candidate. This study may facilitate the design and development of novel TOP1 inhibitors.

Preventing corrosion in the steel reinforcement of concrete structures is crucial for maintaining structural integrity and load-bearing capacity as it directly impacts the safety and lifespan of concrete structures. By preventing rebar corrosion, the durability and seismic performance of the structures can be significantly enhanced. This study investigates the hysteresis behavior of both corroded and non-corroded engineered cementitious composite (ECC)-glass-fiber-reinforced polymer (GFRP) spiral-confined reinforced-concrete (RC) columns. Employing experimental methods and finite element analysis, this research explores key seismic parameters such as crack patterns, failure modes, hysteretic responses, load-bearing capacities, ductility, stiffness degradation, and energy dissipation. The results demonstrate that ECC-GFRP spiral-confined RC columns, compared to traditional RC columns, show reduced corrosion rates, smaller crack widths, and fewer corrosion products, indicating superior crack control and corrosion resistance. Hysteresis tests revealed that ECC-GFRP columns, at a 20% target corrosion rate, exhibit an enhanced load-bearing capacity, ductility, and energy dissipation, suggesting improved durability and seismic resilience. Parametric and sensitivity analyses confirm the finite element model’s accuracy and highlight the significant influence of concrete compressive strength on load-bearing capacity. The findings suggest that ECC-GFRP spiral-confined RC columns offer promising applications in coastal and seismic-prone regions, enhancing corrosion resistance and mechanical properties, thus potentially reducing formwork costs and improving construction quality and efficiency.

Knowledge of academic words, academic formulas and general formulas is essential for second language learners, but resources for incidental learning of these lexical items are very limited, especially in English as a Foreign Language contexts. This study employed a corpus-driven approach to examine the potential of online news for incidental learning of core academic words, academic formulas, and general formulas. Twenty-six corpora were created from voice of America (VOA) news to represent the amounts of reading that learners with the reading speed of 200 words per minute (wpm) and those with the reading speed of 150 wpm could complete within certain periods of time if they read VOA news regularly for 40 minutes per day and 5 days per week. Then, occurrences of core academic words, academic formulas, and general formulas represented by well-known lists in each corpus were counted with corpus-based tools. Analysis showed that the number of core academic words, academic formulas, and general formulas increased steadily as more input was added. Depending on the kind of target vocabulary and the reading speed, reading VOA news regularly for 3 months to 3.5 years would likely offer learners opportunities to encounter nearly all target words/formulas and encounter at least 80% of them 12 or more times in their reading. This finding suggests that online news is a useful resource for incidental vocabulary learning. It also indicates the minimal amounts of reading needed for incidental learning of core academic words, academic formulas, and general formulas.

Agricultural waste fiber has huge utilization potential due to its abundant sources, renewability, and low recycling costs. In this process, up to 30 wt% tobacco stalk fiber (TSF) was compounded with high-density polyethylene (HDPE) and interfacial modifiers using a grinder, melting-blending mixer, and injection molding machine to prepare environmentally friendly TSF/HDPE composites, which have excellent mechanical properties and good water resistance. On this basis, the interfacial compatibility between TSF and HDPE was enhanced by adding a silane coupling agent KH550, titanate coupling agent 201, and maleic anhydride grafted polyethylene (MA-g-PE), which led to the improvement of mechanical properties of composites. The mechanical properties of the composites with 2% MA-g-PE were the best, while the tensile strength and flexural strength increased by 72% and 38%, respectively, compared with the unmodified composites. Fourier transform infrared (FTIR) spectroscopy showed that TSF was modified by different coupling agents and new chemical bonds were formed. The scanning electron microscopy images showed that the interfacial compatibility between TSF and HDPE was improved by the interface modifiers. This work confirms that it is possible to use TSF to prepare composites and provides a new way for resource utilization of tobacco stalk fiber. Highlights * TSF was incorporated into composites, boosting material sustainability. * The interface compatibility between TSF and HDPE was greatly improved. * Thermal and water absorption analysis can be used for composites design. * Composites modified by 2wt% MA-g-PE had optimal comprehensive properties. KEYWORDS Interface modification, mechanical properties, resin matrix composites, tobacco stalk fiber, 1 | INTRODUCTION Natural fibers make a difference in composites by optimizing resource usage due to their abundant sources, renewability, and biodegradability. (1,2) Plant fibers have been closely integrated with [...]