Jilin University

Bauxite plays a crucial role in metallic and non-metallic industry. The surface-exposed salento-type bauxite deposits have been largely exploited and developed. With the increasing demand of these resources, it is important but very challenging to explore the potential bauxite deposits in the deep earth. In this paper, based on new developments in transient electromagnetic (TEM) technologies, we conducted explorations of the sedimentary bauxite in Dengli-Tianyanggumei and Dajia mining areas in western Guangxi province. To achieve a fast and high-resolution inversion, we adopt an array-based observation strategy for large-scale 3-D TEM and collect EM data inside and outside the transmitting loop. Compared to traditional TEM surveys, the observation strategy can quickly acquire the data for large-scale surveys and improve the data acquisition efficiency by more than 25 times. We then use a 3-D inversion algorithm to estimate the underground conductivity structure and analyze the distribution of the sedimentary bauxite. To do that, we discretize the undulating surface and transmitter-receiver locations with unstructured grids and employ the finite-element and quasi-Newton methods to achieve high-resolution imaging of subsurface electrical structures. Since the observation strategy greatly reduces the number of transmitters, the efficiency of 3-D EM inversions can be significantly improved. Experiments over two mining areas show that our inversions can clearly recover the underground resistivities. The inferred burial depth and spatial distribution of the sedimentary bauxite are in agreement with the drilling data. By combining ERT results and geological data, we illustrate the impact of faults on the spatial distribution of potential sedimentary bauxite deposits.

Covalent organic frameworks (COFs) incorporating hydrogen bond donor (HBD) moieties show great promise for heterogeneous catalyst for CO2 cycloaddition. In this work, a catechol‐functionalized COF (BL‐TF‐COF) was constructed via Schiff‐base condensation under solvothermal conditions, which was characterized using powder X‐ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT‐IR), solid‐state ¹³C nuclear magnetic resonance (NMR), scanning electron microscope (SEM), high resolution transmission electron microscope (HR‐TEM), diffuse reflection spectroscopy (DRS) and cyclic voltammetry (CV). BL‐TF‐COF presents high crystallinity, large surface area (523 m² g⁻¹) and remarkable chemical stability, along with abundant hydroxyl functional groups distributed on the pore wall. This framework shows a CO2 adsorption capacity up to 88 mg g⁻¹ at 273 K and 1 bar. The binding locations of the adsorption of CO2 over BL‐TF‐COF was studied by grand canonical Monte Carlo (GCMC) simulations. BL‐TF‐COF displays remarkable catalytic performance for the cycloaddition of CO2 with epoxides under mild conditions. Under the condition of the epichlorohydrin/tetrabutylammonium bromide/BL‐TF‐COF molar ratio of 10210:630:4, the system achieved 62.5% substrate conversion at 25 °C under atmospheric CO2 pressure (1 bar) within 48 h. Mechanistic insights into epoxide adsorption and activation processes were investigated through density functional theory (DFT) calculations.

Autophagy is a recycling process by which eukaryotic cells degrade their own components, and the fruiting body (sexual structure) is a necessary structure for some plant pathogenic fungi to start the infection cycle. However, the transcriptional regulation of plant pathogenic fungal autophagy and autophagy regulating sexual reproduction remains elusive. Here, we provide the report linking autophagy transcription and fruiting body development in phytopathogenic fungi. The forkhead box transcription factor (FOX TF) SsFoxE2 in Sclerotinia sclerotiorum (Ss) binds to the promoters of ATG genes, thus promoting their transcription. SsFoxE2 is phosphorylated by AMP‐activated protein kinase (AMPK) SsSnf1, and the phosphorylated SsFoxE2 interacts with (translationally controlled tumor protein) SsTctp1, leading to enhanced stability and ATG transcription activity of SsFoxE2. Importantly, the regulation of autophagy by SsFoxE2 affects the balance of the ubiquitination system and the early development of the fruiting body, which directly determines the occurrence and prevalence of plant disease. Furthermore, transcriptional binding of FOX TF to ATG gene promoters is conserved in phytopathogenic fungi. Taken together, our results bring new insights into pathogen initiation in phytopathogenic fungi and connect it to other autophagy‐regulated processes in plant pathogens.

To mitigate the concentration polarization caused by non‐ohmic resistance, asymmetric ion exchange membranes (IEMs) with nanochannels of comparable Debye length are frequently employed in salinity gradient energy conversion. Conventional asymmetric IEMs always rely on exogenous interventions to tailor their asymmetries as employing polyelectrolytes or modifying substrate porous membranes. Herein, the endogenous asymmetry of the natural smectite family is leveraged to develop composite membranes comprising structurally asymmetric montmorillonite and saponite sheets (MMT‐SAP). The fabricated MMT‐SAP membrane demonstrates superior ion selectivity and outstanding stability, making it an exceptional salinity gradient energy generation device. Mounted on artificial seawater and river water at 50‐fold salinity gradient, the MMT‐SAP demonstrates a cation selectivity of 0.96 and a high‐power generation output 4.5 W m⁻². The maximum power output is found to reach 8.46 W m⁻² at the pH = 11.0. The theoretical study of MMT‐SAP reveals that a potential ion migration mechanism within layered mineral channels is determined by two crucial factors: channel size and the heterogeneous structure distribution in the smectite‐based membrane.

Scaling activities pose gigantic challenge for underwater equipments, making the development of surfaces with long‐term anti‐scaling functionality crucial. However, the reduction in anti‐scaling performance caused by the loss of air film limits the application of conventional bionic superhydrophobic surfaces underwater. Here, a novel solid slippery surface (SOSLS) is engineered through the strategic integration of carbon nanotubes (CNTs) as a structural reinforcement matrix and paraffin as a phase‐change filler within a polyurethane (PU) host. The SOSLS demonstrates exceptional anti‐scaling performance, as evidenced by performing 240‐day static and 30‐day dynamic scaling tests. Conversely, the superhydrophobic surface (SHS) develops scaling in the short term and shows obvious scaling at 120 days due to the loss of gas film. Additionally, the SOSLS displays self‐healing ability both in air and underwater at different temperature due to solid‐liquid transition of paraffin and reversible dynamic bonds of PU. Meanwhile, the hydrophobic groups of PU and paraffin act as barriers to separate water molecules from SOSLS. This self‐healing capability further improves long‐term anti‐scaling performance of SOSLS underwater, thereby effectively sustaining service life of SOSLS. Furthermore, the SOSLS exhibits remarkable stability, self‐cleaning and anti‐friction properties. Hence, this SOSLS holds promising prospect for relevant real‐world anti‐scaling applicability.

Fatigue failure of welded joints is a performance factor of structural parts under dynamic load, and the effective evaluation of its life is always the key to the service ability of structures. The fatigue failure process of welded joints is complicated because of the non-uniformity of microstructure and asymmetry of structure. This study utilized ultrasonic C-scan imaging for non-destructive testing of the internal connection states of resistance projection welding (RPW). The connection state of RPW before, during and after fatigue test and the characteristic change of ultrasonic detection image were compared. With the occurrence of fatigue failure behavior, the area representing the fusion connection region in the ultrasonic C-scan image changes. The area of the molten connection zone in the ultrasonic images can quantitatively evaluate the fatigue limit of stainless steel RPW joints, providing an effective method for assessing fatigue life in practical engineering applications.