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Deep-sea mining operations demand continuous, drift-free positioning over multi-day missions—a requirement that traditional acoustic dead-reckoning systems struggle to meet due to cumulative error accumulation and frequent DVL bottom-lock loss in sediment plume environments. Inspired by Google Cartographer’s 2D grid mapping paradigm, we present a prior map-based visual localization framework that decouples offline mapping from real-time localization, fundamentally eliminating drift through absolute image registration against pre-built seabed mosaics. By integrating adaptive keyframe selection, Multi-Scale Retinex (MSR) enhancement, and the AD-LG deep feature matching architecture, our system constructs globally consistent seabed maps for absolute positioning. The framework leverages deformable convolutions and LightGlue to effectively mitigate challenges such as low texture and non-rigid distortion. Quantitative validation on tank simulation datasets demonstrates significant superiority over IMU-only and standard fusion schemes; qualitative deployment on real Pacific CCZ imagery confirms near-real-time operational feasibility on an embedded Jetson Orin NX platform. This system establishes visual navigation as a viable backup to acoustic systems, addressing a critical gap in deep-sea mining vehicle autonomy.

Understanding the interaction between submerged water jets and cohesive deep-sea sediment is critical for optimizing deep-sea polymetallic nodule hydraulic mining techniques. This research investigated the distinct erosion behavior of cohesive sediments through laboratory experiments and numerical simulations. Cohesive deep-sea sediments were simulated using bentonite–kaolinite mixtures. A series of laboratory experiments, including vane shear tests and viscosity tests under varying moisture content, were conducted to assess the sediments’ mechanical properties. Experimental submerged water jet erosion tests provided basic data for validating the numerical simulations. A Eulerian multi-fluid (EMF) model was implemented to capture sediment–water jet interactions under varying operational parameters, including jet velocities and nozzle heights. The erosion process was found to comprise three distinct stages, including rapid erosion, steady erosion, and stabilization. Two distinct erosion mechanisms were identified, depending on the jet intensity, which affected the depth and shape of the erosion pits. Quantitative analysis revealed that erosion depth exhibits an approximately linear relationship with jet velocity and nozzle height, whereas the erosion diameter shows nonlinear characteristics. These findings enhance the fundamental understanding of cohesive sediment responses under hydraulic disturbances, providing crucial insights for the design and optimization of efficient deep-sea mining systems.

The conveying hose is an important piece of equipment in the field of Marine engineering. Its spatial configuration and force conditions affect the normal operation of the Marine engineering system. This paper proposes a flexible, fully hose-based conveyance method for the field of deep-sea mining and mainly uses Orcaflex software to simulate and analyze the characteristics of the conveying hose in this system. This paper studies the influences of the top spacing, incoming flow direction, and placement and recovery processes on the configuration characteristics and force conditions of the hose. The conclusion drawn is that the conveying hose studied in this paper can maintain a good spatial configuration underwater and has a stable force condition. When the top spacing is 20 m, the transition of the curved section at the bottom of the hose is relatively smooth. The top tension of the hose has a good adaptability to the top spacing and the direction of the incoming flow. The conveying hose can stably complete the deployment and recovery operations.

The vast seabed holds tremendous resource potential that can provide necessary materials for future human societal development. This study focuses on the mineralogy of seafloor manganese nodules off the coast of China in the Western Pacific and the primary techniques for extracting valuable metal elements from manganese nodules. The research indicates that the main valuable metal elements in the manganese nodules from this region include Cu, Co, Ni, Mn, Fe, etc. The key to extracting these valuable metals lies in reducing Mn(IV) to Mn(II) to disrupt the structure of the nodules, thereby releasing the valuable elements. The extraction processes for the main valuable metal elements of manganese nodules are mainly divided into two categories: pyrometallurgical–hydrometallurgical and solely hydrometallurgical. In order to cope with the challenges of environmental change and improve utilization efficiency, bioleaching, hydrogen metallurgy, and co-extraction are gaining increasing attention. For promoting commercialization, the future development of manganese nodule resources can refer to the technical route of efficient short-process extraction technology, the comprehensive recovery of associated resources, and tail-free utilization.

The deep-sea is rich in mineral resources, and deep-sea polymetallic nodules are considered to be the most likely resource for commercial exploitation. Since the discovery of polymetallic nodules by mankind, researchers around the world have made long and arduous explorations in the exploitation of deep-sea polymetallic nodules and have proposed various mining methods, such as the dragging bucket type, the continuous bucket rope type, the automatic shuttle boat type, and the pipeline -lifting type, and have carried out technical verification accordingly. In the collection of seabed polymetallic nodules, the development and testing of towed type, spiral-driven type, crawler self-propelled type, and suspended type technologies have been carried out, basically realizing the mining technology verification of seabed polymetallic nodules and providing technical support for commercial development. However, according to the demand for commercial development, there are still many technical difficulties in polymetallic nodule-collecting technology, and more focus needs to be placed on the efficiency, environmental protection, intelligence, safety, and reliability of the collecting system in the future. This paper compares the existing progress in collection technology and equipment, and provides ideas and references for the research and development of deep-sea polymetallic nodule-mining technology and equipment.

Background Dry Eye Disease (DED) is a prevalent multifactorial ocular disease characterized by a vicious cycle of inflammation, oxidative stress, and mitochondrial dysfunction on the ocular surface, all of which lead to DED deterioration and impair the patients’ quality of life and social functioning. Currently, anti-inflammatory drugs have shown promising efficacy in treating DED; however, such drugs are associated with side effects. The bioavailability of ocular drugs is less than 5% owing to factors such as rapid tear turnover and the presence of the corneal barrier. This calls for investigations to overcome these challenges associated with ocular drug administration. Results A novel hierarchical action liposome nanosystem (PHP-DPS@INS) was developed in this study. In terms of delivery, PHP-DPS@INS nanoparticles (NPs) overcame the ocular surface transport barrier by adopting the strategy of “ocular surface electrostatic adhesion-lysosomal site-directed escape”. In terms of therapy, PHP-DPS@INS achieved mitochondrial targeting and antioxidant effects through SS-31 peptide, and exerted an anti-inflammatory effect by loading insulin to reduce mitochondrial inflammatory metabolites. Ultimately, the synergistic action of “anti-inflammation-antioxidation-mitochondrial function restoration” breaks the vicious cycle associated with DED. The PHP-DPS@INS demonstrated remarkable cellular uptake, lysosomal escape, and mitochondrial targeting in vitro. Targeted metabolomics analysis revealed that PHP-DPS@INS effectively normalized the elevated level of mitochondrial proinflammatory metabolite fumarate in an in vitro hypertonic model of DED, thereby reducing the levels of key inflammatory factors (IL-1β, IL-6, and TNF-α). Additionally, PHP-DPS@INS strongly inhibited reactive oxygen species (ROS) production and facilitated mitochondrial structural repair. In vivo, the PHP-DPS@INS treatment significantly enhanced the adhesion duration and corneal permeability of the ocular surface in DED mice, thereby improving insulin bioavailability. It also restored tear secretion, suppressed ocular surface damage, and reduced inflammation in DED mice. Moreover, it demonstrated favorable safety profiles both in vitro and in vivo. Conclusion In summary, this study successfully developed a comprehensive DED management nanosystem that overcame the ocular surface transmission barrier and disrupted the vicious cycle that lead to dry eye pathogenesis. Additionally, it pioneered the regulation of mitochondrial metabolites as an anti-inflammatory treatment for ocular conditions, presenting a safe, efficient, and innovative therapeutic strategy for DED and other inflammatory diseases.

Photocatalysts are usually in powder form, which makes it difficult to expand the scale of photocatalysis. Here, we report a Newtonian fluid photocatalyst, which consists of an internal nano-hollow imidazole framework and an external light-excitable liquid chain striking a pose on the stage. Due to the intermolecular interaction at the solid-liquid interface and significant steric hindrance effect, the Newtonian fluid catalyst with higher surface tension can firmly adhere to different kinds of scaffolds via simple printing, such as curved surfaces, inclined walls, and grids. In addition to the easier scale-up, the pore structure of frameworks favors faster CO 2 mass transfer, and the liquid chain with a co-catalytic effect serves as the electron donor for efficient CO 2 photoreduction. In this work, the Newtonian fluid photocatalyst achieves a 57.8-fold increase in CO overflow efficiency (100% selectivity), and this universal synthesis method can convert common organic/inorganic photocatalysts into similar Newtonian fluid photocatalysts. The Newtonian fluid photocatalyst composed of imidazole framework and light-excitable liquid chain can be firmly attached to different types of carriers through printing for easier photocatalytic scaling up and more stable CO 2 photoreduction.

Photoelectrically coupling water splitting at high current density is a promising approach for the acquisition of green hydrogen energy. However, it places significant demands on the photo/electrocatalysts. Herein, rare earth elements doping NiMoO 4 ‐based phosphorus/sulfide heterostructure nanorod arrays (RE‐NiMo‐PS@NF [RE = Y, Er, La, and Sc]) are obtained for solar‐enhanced electrocatalytic water splitting at high current densities. The results of the experiment and density‐functional theory studies illustrate that the Y element as a dopant not only makes the NiMoP 2 /NiMo 3 S 4 /NiMoO 4 heterostructure exhibit excellent solar‐enhanced electrocatalytic activity (hydrogen evolution reaction [HER]: η 1000  = 211 mV, oxygen evolution reaction [OER]: η 1000  = 367 mV) but also optimizes the heterostructure interfacial electron density distributions and HER free energy. In addition, Y‐NiMo‐PS@NF achieves 18.64% solar‐to‐hydrogen efficiency. This study not only provides a new way to synthesize heterostructure electrocatalysts but also inspires the application of solar enhancement strategies for high current density water splitting.

Improvement of selectivity and activity of imprinted photocatalysis is a major challenge for antibiotic photodegradation due to the functional monomers of imprinting hindering the photogenerated carrier migration. Here, an organic imprinted Ag-polyaniline/CoFe2O4/Carbon photocatalyst (IM-Ag-PANI/CoFe2O4/C) was successfully prepared by photo-initiated polymerization which achieved selective photodegradation of tetracycline (TC). The heterojunction formed by the functional monomer Ag@PANI and CoFe2O4/C not only facilitates the separation of photo-excited carriers and the exposure of active sites but also contributes to the selective adsorption capability by imprinted cavity on Ag@PANI, thereby improving the photocatalytic activity and selectivity simultaneously. In addition, the Corncob conversion carbon matrix method and iron-based magnetic character enable a more environmentally friendly and recyclable capability of IM-Ag-PANI/CoFe2O4/C. After using machine learning models to train and predict experimental parameters by changing experimental parameters, the IM-Ag-PANI/CoFe2O4/C can photodegrade 82.23% of TC within 2 h, and it has a selective degradation ability compared to enrofloxacin hydrochloride (EH). This research provides a new idea for the construction of imprinted photocatalytic materials that can improve photocatalytic activity.

Selective photodecomposition of highly toxic pollutants is a significant challenge because the free radicals produced by photocatalyst show an indistinguishable attack on all contaminants in wastewater. To realize selective photodegradation, an organic imprinted Ag-PANI/CdS/Fe3O4/Biochar photocatalyst (IM-Ag-PANI/CdS/Fe3O4/BC) was successfully prepared by photoinitiated polymerization method. The formation of heterojunction facilitates the separation of photoexcited carriers and effectively inhibits the photocorrosion of CdS, thereby improving the photocatalytic activity and stability of photocatalysts. Moreover, the imprinted cavities in Ag-PANI layer help to selectively adsorb and degrade 2-mercapto-1-methylimidazole (MMIZ), resulting in a high selectivity coefficient of 2.40 relative to 5-Mercapto-1-methyltetrazole, and the photodegradation efficiency of MMIZ is boosted up to 76% within 1 h. This work provides a new idea to construct stable photocatalysts with high selectivity for the decontamination of target pollutants.