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Ferromanganese nodules are important marine storehouses for critical metals and windows for changing oceans. Although advanced in situ analytical techniques have been applied to visualize the elemental distribution in the nodule cross‐sections, their spatial distribution remains largely uncertain. This study addresses this gap by employing micro X‐ray fluorescence mapping of parallel nodule cross‐sections to delineate the spatial distributions of critical metals (Mn, Fe, Co, Ti, Ni, and Cu) in three Co‐rich ferromanganese nodules from the northwestern Pacific Ocean. The 10‐layer Os isotopic compositions of one nodule closely align with the well‐documented marine Os isotope evolution of seawater, providing a chronological framework and a maximum age of ∼36 Ma for these nodules. Three concentric chemostratigraphic layers, labeled L1, L2, and L3, were identified from the inside out, based on microscopic structures and the distributions of critical metals. The early growth stage was marked by Mn‐rich, Si‐rich, and high Mn/Fe ratios, suggesting a diagenetic‐driven process attributed to high paleoproductivity conditions because of the low latitude of the study area at that time. The subsequent growth stages are all hydrogenetic in origin to be rich in Fe, Co, and Ti with low Mn/Fe ratios. The apparent detritus present during the second growth stage of the nodules may correspond to the stronger bottom currents in the early Miocene. The final mineralization stage indicates a more stable environment with diminished bottom current activity, leading to the formation of a dense, laminar hydrogenetic layer. Plain Language Summary: The present study bridges the knowledge gap on the spatial distribution of critical metals through the innovative use of micro X‐ray fluorescence mapping on parallel sections of three nodules in the northwestern Pacific Ocean. Os isotope stratigraphy establishes a chronological framework and a maximum age of ∼36 Ma for these nodules. Distinct concentric chemostratigraphic layers, labeled L1, L2, and L3, have been identified in these nodules. The early growth stage of the nodules is characterized by Mn‐rich, Si‐rich and high Mn/Fe ratios, indicative of a diagenetic‐driven process under high paleoproductivity conditions due to the low historical latitude. The subsequent stages are all hydrogenetic in origin to be rich in Fe, Co, and Ti with low Mn/Fe ratios. The apparent detritus present during the second growth stage of the nodules may correspond to the stronger bottom currents in the early Miocene. The final mineralization stage suggested a period of environmental stability with reduced current activity, forming of a hydrogenetic layer enriched in Fe, Co, and Ti. This study not only enhances our understanding of the complex processes that govern the formation and evolution of ferromanganese nodules but also provides deeper insight into the historical shifts within our oceans. Key Points: Ferromanganese nodule was dated via Os isotope stratigraphy and has a maximum age of ∼36 MaMulti‐element integrated maps were produced to assist in obtaining clearer chemostratigraphy images of ferromanganese nodulesSpatial distribution of critical metals and chemostratigraphy in ferromanganese nodules were visualized via multiple parallel cross‐sections [ABSTRACT FROM AUTHOR]

BackgroundBased on the 100 MeV proton cyclotron in the China Institute of Atomic Energy (CIAE), the middle-energy proton irradiation test facility was established and several proton single event effect (SEE) experimental study of micro-and nano-electronic devices were carried out. The proton beam striking the device under test (DUT) is contaminated with neutrons generated as a result of protons interacting with the devices between the accelerator and the DUT. The quality of the proton beam directly affects the effectiveness and accuracy of the experimental cross section of proton SEE.PurposeThis study aims to simulate the proton beam distribution and secondary neutron for intermediate energy proton SEE test.MethodsFirst of all, the geometric model of the proton beam transmission line was established. Then, the Monte Carlo N Particle Transport Code (MCNP) was employed to simulate the proton beam of 100 MeV incidence energy. Results were reduced to the case of single proton incidence, the energy and fluence distribution of proton beams on the sample irradiation plane were obtained, as well as the energy and fluence distribution of the secondary neutrons. Finally, influence of secondary neutrons on the experimental cross section of proton single event effect was analyzed according to the ratio of neutron fluence to proton fluence.Results & ConclusionsSimulation results show the effect of secondary neutrons on the cross section of proton single event effect is insignificant, and the medium energy proton irradiation test facility in CIAE is very suitable for the experimental study of proton single event effects.

BackgroundThe space environment contains numerous high-energy particles, and a single high-energy particle passing through a spacecraft shell bombards the electronic devices within, triggering single-particle effects such as device logic state upset and function failures, which, in turn, affect spacecraft operation reliability and mission accomplishment.PurposeNotably, ground accelerator irradiation tests provide an important and effective means for simulating space single event effects and for predicting the risks of single event effect rates for electronic devices in space applications. Generally, electronic devices can be used in spacecraft only if their resistance radiation indicators meet astronautical application requirements.MethodsSpacecraft are typically exposed to space radiation particles, primarily heavy ions and protons; therefore, single event effect simulation testing for electronic devices relies predominantly on heavy ion and proton accelerators. To address the requirements of single event effect testing, technologies such as large-area beam expansion and homogenization, high-precision beam current diagnosis, and efficient test terminals have been developed to fulfill the requirements of various test tasks.ResultsParticular focus is placed on the CIAE's (China Institute of Atomic Energy) heavy ion single event and proton single event effect simulation test techniques and the heavy ion microbeam technique for radiation sensitive area identification for electronic devices. Subsequently, the aforementioned techniques are applied to a single event effect risk evaluation for astronautical electronic devices.ConclusionsIn the future, the demand for radiation-resistant devices is expected to continue to increase in the aerospace, nuclear industry, and other radiation application fields. It is, therefore, necessary to further exploit the irradiation potential of existing domestic single event effect simulation equipment and establish new accelerator platforms with improved capacity for single event effect simulation testing.

The exposure of spaceborne devices to high-energy charged particles in space results in the occurrence of both a total ionizing dose (TID) and the single-event effect (SEE). These phenomena present significant challenges for the reliable operation of spacecraft and satellites. The rapid advancement of semiconductor fabrication processes and the continuous reduction in device feature size have led to an increase in the significance of the synergistic effects of TID and SEE in static random access memory (SRAM). In order to elucidate the involved physical mechanisms, the synergistic effects of TID and single-event upset (SEU) in a new kind of 130 nm 7T silicon-on-insulator (SOI) SRAM were investigated by means of cobalt-60 gamma-ray and heavy ion irradiation experiments. The findings demonstrate that 7T SOI SRAM is capable of maintaining normal reading and writing functionality when subjected to TID irradiation at a total dose of up to 750 krad(Si). In general, the TID was observed to reduce the SEU cross-section of the 7T SOI SRAM. However, the extent of this reduction was influenced by the heavy ion LET value and the specific writing data pattern employed. Based on the available evidence, it can be proposed that TID preirradiation represents a promising avenue for enhancing the resilience of 7T SOI SRAMs to SEU. [ABSTRACT FROM AUTHOR]

Due to the increasing speed of high-speed trains, the grounding system faces new challenges. When the relative motion between the train and the track occurs, the phenomenon of ground backflow will be intensified, resulting in the rise of train body potential, the abnormity or even damage of bearing and ground carbon brush, insulation joint, on-board sensors and other problems. In view of the existing problems of grounding reflux and train body potential of high-speed trains and the failure of twodimensional model of high-speed train grounding system to simulate and analyze the potential of the left and right sides of the same axle based on radial parameters, it is necessary to conduct a more perfect three-dimensional modeling of the integrated grounding system of high-speed trains. In order to suppress the grounding current and reduce the potential of the vehicle body, optimized analysis of the grounding mode and grounding parameters of the grounding system is conducted. In this paper, based on the measured data and theoretical analysis of the impedance and inductance parameters of the train body as well as the actual size parameters of the train body by the RCL tester, the three-dimensional circuit model of the integrated grounding system of the high-speed train is completed respectively from the aspects of traction transformer, overhead contact line, on-board transformer of high-speed train, high-voltage cable and train body under the premise of fully considering all the influencing factors. At the same time, combined with the dynamic grounding reflux test of the train passing under the on-line condition and the static overvoltage test of the high-speed train raising the pantograph and closing the VCB, the simulation results are compared with the measured results to verify the reliability of the three-dimensional model. Finally, based on the threedimensional simulation model, the radial parameters of the docking system and the three-dimensional distribution of the protection grounding and working grounding are optimized. After optimization, the ground current flowing through the protection grounding of the train is reduced to different degrees, and the distribution becomes more uniform. Meanwhile, the potential of the train body is maintained within the safety limit. [ABSTRACT FROM AUTHOR]

The collective Unmanned Weapon System-of-Systems (UWSOS) network represents a fundamental element in modern warfare, characterized by a diverse array of unmanned combat platforms interconnected through heterogeneous network architectures. Despite its strategic importance, the UWSOS network is highly susceptible to hostile infiltrations, which significantly impede its battlefield recovery capabilities. Existing methods to enhance network resilience predominantly focus on basic graph relationships, neglecting the crucial higher-order dependencies among nodes necessary for capturing multi-hop meta-paths within the UWSOS. To address these limitations, we propose the Enhanced-Resilience Multi-Layer Attention Graph Convolutional Network (E-MAGCN), designed to augment the adaptability of UWSOS. Our approach employs BERT for extracting semantic insights from nodes and edges, thereby refining feature representations by leveraging various node and edge categories. Additionally, E-MAGCN integrates a regularization-based multi-layer attention mechanism and a semantic node fusion algorithm within the Graph Convolutional Network (GCN) framework. Through extensive simulation experiments, our model demonstrates an enhancement in resilience performance ranging from 1.2% to 7% over existing algorithms. [ABSTRACT FROM AUTHOR]

In our research, we utilized six small-fruited pepper germplasms as materials, selected cotyledons with the petiole and hypocotyls as explants, and conducted in vitro regeneration studies. Our outcomes specify that the most suitable explant is cotyledon with the petiole, and the suitable genotype is HNUCA341. The optimal medium for inducing and elongating adventitious buds for this genotype is Murashige and Skoog medium (MS) + 9.12 μM Zeatin (ZT) + 0.57 μM 3-Indoleacetic acid (IAA), with a bud induction rate of 44.4%. The best rooting induction medium is MS + 1.14 μM IAA, with a rooting rate of 86.7%. Research on the addition of exogenous hormones has revealed that the induction speed of buds in small-fruited pepper (HNUCA341) in the combination of ZT and IAA hormones (abbreviated as ZI) is quicker, and the induction effect is better. The histological observations indicate that ZI treatment accelerates the initiation of explant division and differentiation, causing a shorter duration of vascular-bundle tissue production. The plant hormone signaling pathway was significantly enriched by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, including ARR9 (LOC107843874, LOC107843885), ARR4 (LOC107848380, LOC107862455), AHK4 (LOC107870540), AHP1 (LOC107839518), LAX2 (LOC107846008), SAUR36 (LOC107852624), IAA8 (LOC107841020), IAA16 (LOC107839415), PYL4 (LOC107843441), and PYL6 (LOC107871127); these significantly enriched genes may be associated with in vitro regeneration. In addition, the carbon metabolism pathway and plant mitogen-activated protein kinase (MAPK) signaling pathway are also significantly enriched in KEGG. The results of the Gene Ontology (GO) analysis revealed that differentially expressed genes related to carbon metabolism and fixation, photosynthesis and MAPK signaling pathways were upregulated under ZI treatment. It was found that they might be associated with enhanced regeneration in vitro. Furthermore, we also screened out differentially expressed transcription factors, primarily from the MYB, bHLH, AP2/ERF, and NAC families. Overall, our work accumulated important data for the in-depth analysis of the molecular mechanism of in vitro regeneration of pepper, and provides valuable germplasm for establishing an efficient stable pepper genetic-transformation system based on tissue culture. [ABSTRACT FROM AUTHOR]

We report that the mammalian 5-methylcytosine (5mC) oxidase Tet3 exists as three major isoforms and characterized the full-length isoform containing an N-terminal CXXC domain (Tet3FL). This CXXC domain binds to unmethylated CpGs, but, unexpectedly, its highest affinity is toward 5-carboxylcytosine (5caC). We determined the crystal structure of the CXXC domain-5caC-DNA complex, revealing the structural basis of the binding specificity of this domain as a reader of CcaCG sequences. Mapping of Tet3FL in neuronal cells shows that Tet3FL is localized precisely at the transcription start sites (TSSs) of genes involved in lysosome function, mRNA processing, and key genes of the base excision repair pathway. Therefore, Tet3FL may function as a regulator of 5caC removal by base excision repair. Active removal of accumulating 5mC from the TSSs of genes coding for lysosomal proteins by Tet3FL in postmitotic neurons of the brain may be important for preventing neurodegenerative diseases.

BackgroundSilicon carbide junction barrier Schottky (SiC JBS) diode is a kind of power device based on wide bandgap semiconductor. SiC JBS diode is expected to become an important part of electric propulsion systems in the radiation application field in the future space exploration due to its excellent high-voltage, high-frequency and high-power characteristics. However, there are a large number of protons in the typical orbit of spacecraft, which always threaten the stable operation of spacecraft, including its key components.PurposeThis study aims to explore the resist ability of SiC JBSs to the degradation of medium energy proton irradiation, and clarify the mechanism of radiation effect of SiC JBSs from medium energy proton.MethodsBased the proton equivalent displacement damage dose in low Earth orbit for ten years, the SiC JBSs were firstly irradiated using 10 MeV protons at fluences ranging from 3×109 cm-2 to 3×1010 cm-2 at room temperature and without bias voltage. And the macro electrical characteristics of the SiC JBSs both before and after irradiation, including the forward current-voltage (I-V), reverse I-V and capacitance-voltage (C-V) characteristics, were tested. Then the irradiation-induced defects characteristics were tested by deep level transient spectrum (DLTS). Further, the related degradation mechanism that was associated with this phenomenon was also investigated using based on the test data and mathematical calculation. Finally, irradiation experiments of accelerator protons were carried out for commercial SiC JBSs.ResultsThe results show that the forward electrical characteristic of the SiC JBSs is stable, and the leakage current decreases at low reverse safety voltage. But the rated breakdown voltage is seriously degraded with the increase of irradiation fluence. The main contribution to the change of SiC JBSs characteristics originates from the increase of interface charge, deep level defects and Schottky barrier height, and the decrease of carrier density and carrier diffusion length in the drift region.ConclusionsAnalysis of the radiation damage process and mechanism of SiC JBSs in this study provides a research basis for its evaluation and verification before applied to medium energy proton environment.

The assessment of forest site quality at early stages of stand development is very essential for scientific afforestation and forest management. In order to enhance the accuracy of the existing models, a new site quality assessment model based on Genetic Algorithm-Radial Basis Function (GA-RBF) was proposed to predict site index (stand dominant height). Data used in this study came from 980 permanent sample plots for Chinese fir (Cunninghamia lanceolata) plantations in Fujian Province, China, which were randomly divided into the training dataset (786 plots) and the testing dataset (194 plots) with a ratio of 8:2. In this paper, the GA-RBF was compared with the radial basis function (RBF) and the traditional Quantitative Theory I (QT-I) method. The results indicated that the predicted accuracy was significantly increased by using the GA-RBF model. Furthermore, we used the existing site-specific site index table of Chinese fir to test the results of the GA-RBF and the agreement was 73.2%. Therefore, we recommend the GA-RBF for assessing site quality of afforestation land.

The bottom of the ocean is rich in mineral resources, and deep-sea mining has been a research hotspot in recent years. As a key part of deep-sea mining operation, polymetallic nodule collection technology has been researched in many countries around the world. The distribution of deep-sea polymetallic nodule mining areas and the characteristics of nodules are summarized, which provides a reference for the study of collection technology and the optimization of pick-up device structure. In order to further establish a deep-sea mining collection technology system, the current development status of polymetallic nodule mechanical, mechanical–hydraulic composite and hydraulic collection technologies are summarized, and the analysis shows that hydraulic collection technology has a more promising commercialization prospect. For the hydraulic collection technology, the research progress of suck-up-based collection technology, Coandă-effect-based collection technology, double-row hydraulic collection sluicing technology and other collection technologies are summarized from three aspects: collecting principle, device structure parameter optimization, and sea trial situation, and the key technical problems of hydraulic ore collection are put forward. Through the comparative analysis of the pick-up efficiency, energy consumption, environmental disturbance and other performances of different devices, it is found that the Coandă-effect-based hydraulic collection technology has better comprehensive performance. A structural design evaluation indicator for the collection head of hydraulic collection technology is proposed, and the prospect of further research on hydraulic collection technology is put forward. [ABSTRACT FROM AUTHOR]

OTOF mutations are the principal causes of auditory neuropathy. There are reports on Otof‐related gene therapy in mice, but there is no preclinical research on the drug evaluations. Here, Anc80L65 and the mouse hair cell‐specific Myo15 promoter (mMyo15) are used to selectively and effectively deliver human OTOF to hair cells in mice and nonhuman primates to evaluate the efficacy and safety of OTOF gene therapy drugs. A new dual‐AAV‐OTOF‐hybrid strategy to transfer full‐length OTOF is generated, which can stably restore hearing in adult OTOFp.Q939*/Q939* mice with profound deafness, with the longest duration being at least 150 days, and the best therapeutic effect without difference in hearing from wild‐type mice. An AAV microinjection method into the cochlea of cynomolgus monkeys without hearing impairment is further established and found the OTOF can be safely and effectively driven by the mMyo15 promoter in hair cells. In addition, the therapeutic dose of AAV drugs has no impact on normal hearing and does not cause significant systemic toxicity both in mouse and nonhuman primates. In summary, this study develops a potential gene therapy strategy for DFNB9 patients in the clinic and provides complete, standardized, and systematic research data for clinical research and application. [ABSTRACT FROM AUTHOR]

BACKGROUND: In recent years, lower limb walking exoskeletons have been widely used in the study of spinal cord injury (SCI). OBJECTIVE: To explore the effect of a lower limb walking exoskeleton on quality of life and functional independence in patients with motor complete SCI. METHODS: This was a multi-center, single blind, randomized controlled trial. A total of 16 SCI patients were randomly assigned to either the exoskeleton-assisted walking (EAW) group (n = 8) or the conventional group (n = 8). Both groups received conventional rehabilitation training, including aerobic exercise and strength training. The EAW group additionally conducted the exoskeleton-assisted walking training using an AIDER powered robotic exoskeleton for 40–50 minutes, 5 times/week for 8 weeks. World Health Organization quality of life-BREF (WHOQOL-BREF) and the Spinal Cord Independence Measure III (SCIM-III) were used for assessment before and after training. RESULTS: There was an increasing tendency of scores in the psychological health, physical health, and social relationships domain of WHOQOL-BREF in the EAW group after the intervention compared with the pre-intervention period, but there was no significant difference (P > 0.05). SCIM-III scores increased in both groups compared to pre-training, with only the conventional group showing a significant difference after 8 weeks of training (P < 0.05). CONCLUSION: A lower limb walking exoskeleton may have potential benefits for quality of life and activities of daily living in patients with motor complete SCI. [ABSTRACT FROM AUTHOR]