3D Framework Research Articles

Exploring high-order correlation for hyperspectral image denoising with hypergraph convolutional network

High-order correlation is an important property of hyperspectral images (HSIs) and has been widely investigated in model-based HSI denoising. However, the existing deep learning-based HSI denoising approaches have not fully utilized the high-order correlation. Hypergraph convolutional networks have shown great potential in capturing the high-order correlation. Therefore, in this paper, we propose a novel HSI denoising method by employing hypergraph convolution to characterize the high-order correlation at the patch level. Specifically, our framework is a symmetrically skip-connected 3D encoder–decoder architecture, which enhances the extraction and utilization of local features. Furthermore, to integrate competently the hypergraph convolutional modules into the 3D framework, we devise a dimensional transformation module that facilitates the fusion of 3D convolution and hypergraph convolution. Notably, in the hypergraph convolution operation, we use a data-driven technique to acquire the incidence matrix of a hypergraph, efficiently constructing the HSI into a high-order structure. Our proposed method excels in HSI denoising performance compared to state-of-the-art approaches, evidenced by extensive experiments on synthetic and real-world noisy HSIs.

Dual Eu3+ and Er3+ doping in ZnO nanoporous 2D frameworks for tuning photocatalytic activity, linear and non-linear optical response

Recent days, the greater attention of research materials are focusing on the porous nano frame structure due to their distinctive properties and high photocatalytic activity. The porous defective materials revealed a significant role in numerous research fields like sensors, catalysts, energy production, magnetic memory storage, bio medical etc. In our work, pure ZnO and 4f shell shielded rare earth metals doped ZnO metal oxide nanomaterials attributed in the photocatalytic dye degradation, non-linear optical and magnetic properties. We were synthesized pure ZnO and ZnO0.1–2xEuxErxHMT0.1–2x (2x = 0.025,0.05,0.075, 0.010 wt%) nanoparticles using a straightforward hydrothermal route. The hexagonal wurtzite structure of ZnO and Eu:Er-doped ZnO (Eu:Er@ZnO) exhibited by PXRD, and the optical bandgap (Eg) range from 3.14 eV to 3.18 eV was determined by Tauc relation (αhγ)2 = 0. The porous nanoplate morphology of as-synthesized materials revealed by HR-SEM and HR-TEM techniques. All synthesized materials exposed weak ferromagnetic property nature by VSM studies. Among all the synthesized materials, the 0.0025 wt% Eu:Er@ZnO nanoparticles exhibited porous nanoplate structures capable of catalyzing the breakdown of reactive black 5 (RB5) dye, achieving a photocatalytic activity of 93.2 % after 65 min of UV light exposure. The dopant concentration significantly influenced this photocatalytic activity, with lower concentrations showing enhanced performance, particularly in acidic conditions. Moreover, all synthesized porous nano-plate materials followed pseudo-first-order kinetics. Additionally, the Z-scan technique was employed to assess the nonlinear optical properties of the synthesized materials using Q-switched nanosecond Nd laser pulses at 532 nm wavelength. The open-aperture Z-scan revealed reverse saturable absorption (RSA) in all samples. The Eu:Er@ZnO porous nano-plates exhibited promising nonlinear absorption characteristics, with a higher nonlinear absorption coefficient ranging from 5.21 to 7.84 × 10−11 m/W and a lower optical limiting threshold between 0.87 and 0.95 × 1012 W/m2.

Modeling and Optimization of Modified TiO2 with Aluminum and Magnesium as ETL in MAPbI3 Perovskite Solar Cells: SCAPS 1D Frameworks.

The perovskite device, incorporating a modified nanostructure of TiO2 as the electron transport layer, has been investigated to enhance its performance compared to the pure TiO2 device. Various materials undergo electrochemical doping or treatment on TiO2 to improve their photocatalytic application, thereby enhancing the current density, minimizing recombination, and improving device stability. In this study, a numerical SCAPS simulation was employed to validate experimental findings from the literature. According to the literature, this marks the first instance of doping Al3+ and Mg2+ on TiO2 due to their ionic radius comparable to that of Ti4+, at different doping concentrations. The device was modeled and simulated with the experimental parameters of bandgap, series, and shunt resistances for pure TiO2, aluminum-doped TiO2 (Al-TiO2), and magnesium-doped TiO2 (Mg-TiO2). From the validated results, the Al-TiO2 and Mg-TiO2-based devices' configurations with minimum percentage errors of 0.427 and 2.771%, respectively, were selected and simulated across nearly 90 (90) configurations to determine the optimum device model. Optimizing absorber thickness, bandgap, doping concentration, metal electrode, as well as series and shunt resistance resulted in enhanced device performance. According to the proposed model, Al-TiO2 and Mg-TiO2 configurations achieved higher power conversion efficiency values of 19.260 and 19.860%, respectively. This improvement is attributed to the reduction in recombination rates through the injection of a higher photocurrent density.

Reaction Time Induced a Two-Step Dissolution and Recrystallization Structural Transformation with Three Eu Metal-Organic Frameworks: Crystal Structures and Multiresponsive Fluorescence Detection.

Under solvothermal conditions, three 3D lanthanide metal-organic frameworks (Ln-MOFs): [Eu(H2DHTA)1.5(DMF)2]·DMF (1), [Eu(H2DHTA)0.5(DHTA)0.5(DMF)(H2O)]·2H2O (2), and Eu(HCOO)3 (3) (H4DHTA = 2,5-dihydroxyterephthalic acid) have been synthesized by different reaction times. Interestingly, induced by reaction time, compounds 1-3 underwent a two-step dissolution and recrystallization structural transformation (DRST) reaction. Investigations on the DRST processes were carried out, and the transformation pathway was deduced, which was verified by XRD analyses. Notably, compound 2 demonstrates pronounced luminescence as well as high stability in water and other organic solvents. The fluorescent detection of furan antibiotics can serve as turn-off effects, and glutamic acid (Glu), aspartic acid (Asp), and riboflavin (VB2) can serve as the turn-on effect. To explain the enhancing and quenching mechanisms, XRD, UV-visible absorption spectroscopy, electrochemistry, IR spectra, theoretical calculation, fluorescence lifetimes, and XPS were discussed. Additionally, MOF-coated test strips were utilized to detect these analytes, exhibiting excellent agreement with fluorescence spectroscopy. This work provides an example for more effective designs to employ Ln-MOFs as multiresponsive fluorescent sensors for detection of environmental pollutants in aqueous solution.

Silver-quercetin-loaded honeycomb-like Ti-based interface combats infection-triggered excessive inflammation via specific bactericidal and macrophage reprogramming

Excessive inflammation caused by bacterial infection is the primary cause of implant failure. Antibiotic treatment often fails to prevent peri-implant infection and may induce unexpected drug resistance. Herein, a non-antibiotic strategy based on the synergy of silver ion release and macrophage reprogramming is proposed for preventing infection and bacteria-induced inflammation suppression by the organic-inorganic hybridization of silver nanoparticle (AgNP) and quercetin (Que) into a polydopamine (PDA)-based coating on the 3D framework of porous titanium (SQPdFT). Once the planktonic bacteria (e.g., Escherichia coli, Staphylococcus aureus) reach the surface of SQPdFT, released Que disrupts the bacterial membrane. Then, AgNP can penetrate the invading bacterium and kill them, which further inhibits the biofilm formation. Simultaneously, released Que can regulate macrophage polarization homeostasis via the peroxisome proliferators-activated receptors gamma (PPARγ)-mediated nuclear factor kappa-B (NF-κB) pathway, thereby terminating excessive inflammatory responses. These advantages facilitate the adhesion and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs), concomitantly suppressing osteoclast maturation, and eventually conferring superior mechanical stability to SQPdFT within the medullary cavity. In summary, owing to its excellent antibacterial effect, immune remodeling function, and pro-osteointegration ability, SQPdFT is a promising protective coating for titanium-based implants used in orthopedic replacement surgery.

Influence of Metal Ions on the Structural Complexity of Mixed-Ligand Divalent Coordination Polymers

The reactions of the angular ligand 4,4′-oxybis(N-(pyridin-3-yl)benzamide) (L1) and 1,4-naphthalenedicarboxylic acid (1,4-H2NDC) with divalent metal salts yielded three distinct coordination polymers (CPs): {[Zn2(L1)(1,4-NDC)2]·MeOH}n, 1, {[Cu(L1)(1,4-NDC)(H2O)]·3H2O}n, 2, and {[Cd(L1)(1,4-NDC)]·2H2O}n, 3. Complex 1 features a 2-fold interpenetrated 3D framework with the (412·63)-pcu topology, while complex 2 reveals a 1D triple-strained helical chain and complex 3 displays a 3-fold interpenetrated 3D framework with (66)-dia topology. Additionally, the reactions of the flexible ligand N,N′-bis(3-methylpyridyl) adipoamide (L2) afforded {[Co4(L2)0.5(1,4-NDC)3(H2O)3(µ3-OH)2]·EtOH·2H2O}n, 4, {[Zn2(L2)(1,4-NDC)2]·2CH3OH}n, 5, and [Cd(L2)(adipic)(H2O)]n (H2adipic = adipic acid), 6, exhibiting a self-catenated 3D framework with the (420·68)-8T32 topology, a 2D layer with the (413·62) − (4,4)IIb topology, and a 2D layer with the (44·62)-sql topology, respectively. The structural diversity observed in complexes 1–6 highlights the pivotal influence of the metal center on the degree of entanglement in CPs within mixed-ligand systems. The thermal stability and luminescent properties of complexes 1–3, 4, and 6 are also discussed.

Thermally Conductive Polydimethylsiloxane-Based Composite with a Three-Dimensional Vertically Aligned Thermal Network Incorporating Hexagonal Boron Nitride Nanosheets and Nanodiamonds.

Thermal interface materials play a pivotal role in efficiently transferring heat from heating devices to thermal management components, thereby reducing the risk of component degradation due to overheating. In this study, we propose a strategy for enhancing the out-of-plane thermal conductivity (TC) of composite materials by fabricating a three-dimensional (3D) thermal network within a polydimethylsiloxane (PDMS) matrix. Specifically, the composite material was designed to incorporate a dense thermal network comprising hexagonal boron nitride nanosheets (BNNSs) and nanodiamonds (NDs). The fabrication process commenced with the preparation of BNNSs through liquid-phase exfoliation, followed by the creation of a 3D BNNSs-NDs/polyimide aerogel thermal framework using a unidirectional solidification ice templating method and subsequent heat treatment. Vacuum impregnation and curing were then employed to finalize the production of the 3D BNNSs-NDs/PDMS composite material. Characterization analyses indicated that the addition of NDs filled the voids between BNNSs, leading to the densification of the thermal framework pore walls and the establishment of additional thermal pathways. Impressively, with concentrations of BNNSs and NDs of 17.99 and 7.71 wt %, respectively, the out-of-plane TC of the 3D BNNSs-NDs/PDMS composite material reached 1.623 W m-1 K-1, marking notable enhancements of 754.21% and 256.70% compared to those of pure PDMS and composites prepared via direct blending with randomly distributed BNNSs and NDs, respectively. Furthermore, the 3D BNNSs-NDs thermal framework improved the compressive strength and the dimensional stability of the composite material. Finite element simulations additionally confirmed the synergistic improvement of the TC achieved through the combination of BNNSs and NDs, demonstrating that the 3D BNNSs-NDs/PDMS composite material displayed superior heat conduction and a greater density of thermal pathways compared to those of its counterparts, including 3D BNNSs/PDMS and 3D NDs/PDMS composite materials. In summary, this work presents a strategy for enhancing the out-of-plane TC of polymer-based composite materials by incorporating vertically aligned thermal networks.

A 3D open-framework amino acid templated cerium phosphite-oxalate showing proton conductive property

Using L-histidine as template, a three-dimensional (3D) open-framework cerium phosphite-oxalate, Ce2(H2O)2(H2PO3)2(C2O4)3·C6H11N3O2·H2O (1), has been synthesized under hydrothermal condition. Interestingly, it is the first example of lanthanide phosphite-oxalate with amino acid as the template. Compound 1 shows 3D framework with 8-, 12- and 20-ring channels and has a mog Moganite topology. A large amount of free water molecules and histidine cations are located in the channels of 1, which are favorable to the efficient proton transfer. Correspondingly, compound 1 displays temperature and humidity dependent proton conductivity with the highest value of 3.67 × 10−4 S cm−1 at 75 °C and 98 % RH.

Learning 3D human–object interaction graphs from transferable context knowledge for construction monitoring

We propose a novel framework for detecting 3D human–object interactions (HOI) in construction sites and a toolkit for generating construction-related human–object interaction graphs. Computer vision methods have been adopted for construction site safety surveillance in recent years. The current computer vision methods rely on videos and images, with which safety verification is performed on common-sense knowledge, without considering 3D spatial relationships among the detected instances. We propose a new method to incorporate spatial understanding by directly inferring the interactions from 3D point cloud data. The proposed model is trained on a 3D construction site dataset generated from our crafted simulation toolkit. The model achieves 54.11% mean interaction over union (mIOU) and 72.98% average mean precision(mAP) for the worker–object interaction relationship recognition. The model is also validated on PiGraphs, a benchmarking dataset with 3D human–object interaction types, and compared against other existing 3D interaction detection frameworks. It was observed that it achieves superior performance from the state-of-the-art model, increasing the interaction detection mAP by 17.01%. Besides the 3D interaction model, we also simulate interactions from industrial surveillance footage using MoCap and physical constraints, which will be released to foster future studies in the domain.

Identification of S-phenylmercapturic acid using heterometallic Zn–Eu MOF as a fluorescence sensor

S-phenylmercapturic acid (S-PMA) can be served as an important biomarker for detecting benzene metabolites in clinical diagnosis. In this work, a 3D luminescent heterometal-organic framework (HMOF) with two kinds of pores was designed and synthesized by choosing d/f heterometals salts and two ligands with abundant coordination sites, {[EuZn2(imdc)2(bpe)(H2O)3(OH)]·bpe}n (H3imdc = 1H-imidazole-4,5-dicarboxylic acid; bpe = 1,2-bis (4-pyridyl)-ethylene), namely, MOF 1, which could be utilized to selectively recognize S-PMA by the fluorescence quench. It demonstrated that an efficient recoverable luminescent probe MOF 1 had determined S-PMA with excellent sensitivity (the limit of detection = 3.0 × 10–8 M), rapid response time (less than 20 s), and a wide linear concentration range (3.70 ∼ 180 µM). More interestingly, this is the first instance of utilizing a luminescent MOF for the detection of S-PMA. A low-cost portable composite film for the convenient detection of S-PMA had been designed to recognize S-PMA by visual changes in luminescent color. In addition, the fluorescence sensing mechanism of S-PMA by MOF 1 was elaborated.

Lithiation Induced Hetero-Superlattice Zn/ZnLi as Stable Anode for Aqueous Zinc-Ion Batteries.

Three dimensional (3D) framework structure is one of the most effective ways to achieve uniform zinc deposition and thus inhibit the Zn dendrites growth in working Zn metallic anode. A major challenge facing for the most commonly used 3D zincophilic hosts is that the zincophilic layer tends to peel off during repeatedly cycling, making it less stable. Herein, for the first time, a hetero-superlattice Zn/ZnLi (HS-Zn/ZnLi) anode containing periodic arrangements of metallic Zn phase and zincophilic ZnLi phase at the nanoscale, is well designed and fabricated via electrochemical lithiation method. Based on binding energy and stripping energy calculation, and the operando optical observation of plating/stripping behaviors, the zincophilic ZnLi sites with a strong Zn adsorption ability in the interior of the 3D ZnLi framework structure can effectively guide uniform Zn nucleation and dendrite-free zinc deposition, which significantly improves the cycling stability of the HS-Zn/ZnLi alloy (over 2800 h without a short-circuit at 2 mA cm-2). More importantly, this strategy can be extended to HS-Zn/ZnNa and HS-Zn/ZnK anodes that are similar to the HS-Zn/ZnLi microstructure, also displaying significantly enhanced cycling performances in AZIBs. This study can provide a novel strategy to develop the dendrite-free metal anodes with stable cycling performance.

Lithiation Induced Hetero‐Superlattice Zn/ZnLi as Stable Anode for Aqueous Zinc‐Ion Batteries

AbstractThree dimensional (3D) framework structure is one of the most effective ways to achieve uniform zinc deposition and thus inhibit the Zn dendrites growth in working Zn metallic anode. A major challenge facing for the most commonly used 3D zincophilic hosts is that the zincophilic layer tends to peel off during repeatedly cycling, making it less stable. Herein, for the first time, a hetero‐superlattice Zn/ZnLi (HS−Zn/ZnLi) anode containing periodic arrangements of metallic Zn phase and zincophilic ZnLi phase at the nanoscale, is well designed and fabricated via electrochemical lithiation method. Based on binding energy and stripping energy calculation, and the operando optical observation of plating/stripping behaviors, the zincophilic ZnLi sites with a strong Zn adsorption ability in the interior of the 3D ZnLi framework structure can effectively guide uniform Zn nucleation and dendrite‐free zinc deposition, which significantly improves the cycling stability of the HS−Zn/ZnLi alloy (over 2800 h without a short‐circuit at 2 mA cm−2). More importantly, this strategy can be extended to HS−Zn/ZnNa and HS−Zn/ZnK anodes that are similar to the HS−Zn/ZnLi microstructure, also displaying significantly enhanced cycling performances in AZIBs. This study can provide a novel strategy to develop the dendrite‐free metal anodes with stable cycling performance.

Sulfurized Two-Dimensional Conductive Metal-Organic Framework as a High-Performance Cathode Material for Rechargeable Mg Batteries.

Rechargeable Mg batteries are a promising energy storage technology to overcome the limitations inherent to Li ion batteries. A critical challenge in advancing Mg batteries is the lack of suitable cathode materials. In this work, we report a cathode design that incorporates S functionality into two-dimensional metal-organic-frameworks (2D-MOFs). This new cathode material enables good Mg2+ storage capacity and outstanding cyclability. It was found that upon the initial Mg2+ insertion and disinsertion, there is an apparent structural transformation that crumbles the layered 2D framework, leading to amorphization. The resulting material serves as the active material to host Mg2+ through reduction and/or oxidation of S and, to a limited extent, O. The reversible nature of S and O redox chemistry was confirmed by spectroscopic characterizations and validated by density functional calculations. Importantly, during the Mg2+ insertion and disinsertion process, the 2D nature of the framework was maintained, which plays a key role in enabling the high reversibility of the MOF cathode.

A new three-dimensional barium(II) coordination polymer constructed from N,N'-bis(glycinyl)pyromellitic diimide: microwave-assisted synthesis, structure, Hirshfeld surface analysis and properties.

A new three-dimensional (3D) coordination polymer, namely, poly[diaqua[μ5-2,2'-(1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole-2,6-diyl)diacetato]barium(II)], [Ba(C14H6N2O8)(H2O)2]n, (I), has been synthesized by the microwave-irradiated reaction of Ba(NO3)2 with N,N'-bis(glycinyl)pyromellitic diimide {BGPD, namely, 2,2'-(1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole-2,6-diyl)diacetatic acid, H2L}. The title compound was structurally characterized by single-crystal X-ray diffraction analysis and powder X-ray diffraction analysis, as well as IR spectroscopy. In the crystal structure of (I), the BaII ion is nine-coordinated by six carboxylate O atoms from five symmetry-related L2- dianions and one imide O atom, as well as two water O atoms. The coordination geometry of the central BaII ion can be described as a spherical capped square antiprism. One carboxylate group of the ligand serves as a μ3-bridge linking the BaII cations into a one-dimensional polynuclear secondary building unit (SBU). Another carboxylate group of the ligand acts as a μ2-bridge connecting the 1D SBUs, thereby forming a two-dimensional (2D) SBU. The resulting 2D SBUs are extended into a 3D framework via the pyromellitic diimide moiety of the ligand as a spacer. The 3D Ba framework can be simplified as a 5-connected hexagonal boron nitride net (bnn) topology. The intermolecular interactions in the 3D framework were further investigated by Hirshfeld surface analysis and the results show that the prominent interactions are H...O (45.1%), Ba...O (11.1%) and C...H (11.1%), as well as H...H (11.1%) contacts. The thermal stability, photoluminescence properties and UV-Vis absorption spectra of (I) were also investigated. The coordination polymer exhibits a fluorescence emission with a quantum yield of 0.071 and high thermal stability.

A Chemically Robust 2D Ni-MOF as an Efficient Heterogeneous Catalyst for One-Pot Synthesis of Therapeutic and Bioactive 2-Amino-3-Cyano-4H-Pyran Derivatives.

Despite possessing numerous catalytic advantages of MOFs, developing 2D frameworks having excellent chemical stability along with new catalytic properties, remains a grand challenge. Herein, by employing a mixed ligand synthetic approach, we have constructed a 2D Ni-MOF, IITKGP-52, which exhibits excellent framework robustness in open air, water, as well as over a wide range of pH solutions (2-12). Benefitting from its robustness and abundant Lewis acidic open metal sites, IITKGP-52 is explored in catalyzing the heterogeneous three-component condensation reaction for the tandem synthesis of bioactive 2-amino-3-cyano-4H-pyran derivatives with low catalytic loading, greater compatibility for a wide range of substrates, excellent recyclability and superior catalytic efficiency than the previously employed homo and heterogeneous systems. IITKGP-52inaugurates the employment of MOF-based catalysts for one-pot synthesis of therapeutic and bioactive 2-amino-3-cyano-4H-pyran derivatives.

One-step self-assembled biomass carbon aerogel/carbon nanotube/cellulose nanofiber composite for supercapacitor flexible electrode

Flexible and exceptionally lightweight energy storage devices are crucial for wearable electronic gadgets. Biomass materials are emerging as ideal flexible electrode components due to their biocompatibility and non-toxic nature. In this study, pineapple leaf fibers were utilized to create activated biomass carbon aerogel (Bio-CAA). Then, carbon nanotubes (CNTs) were integrated as conductive additives, combined with sturdy pineapple leaf cellulose nanofibers (CNFs) to establish a robust 3D framework. Utilizing a one-step self-assembly method, carbon aerogel/carbon nanotube/carbon nanofiber (Bio-CAA/CNT/CNF) flexible composite electrode materials were successfully synthesized. The porous structure of Bio-CAA effectively minimized the aggregation of CNTs, thereby significantly enhancing the electrochemical performance of the electrode material. The characterization indicated that the carbon aerogel composite exhibited a high specific surface area (684.275 m2 g−1) after tablet compression. The material was light yet robust, capable of being bent arbitrarily and recovering its original shape and withstanding 400 Kpa of pressure at an 88 % strain rate, demonstrating excellent mechanical properties. In a three-electrode system, the Bio-CAA/CNT/CNF = 19:1:1 based electrode exhibited a capacitance of 481 F g−1 at a current density of 1 A g−1. The CAA/CNT/CNF = 19:1:1 based solid symmetric supercapacitor (SSC) displayed excellent cycling stability, preserving 91.7 % capacitance after 10,000 cycles at a current density of 5 A g−1. It achieved an energy density of 39.63 Wh kg−1 at a power density of 500 W kg−1. This biomass-derived carbon aerogel-based composite material demonstrates exceptional energy storage capabilities, and its lightweight attributes make it highly suitable for use in flexible displays, wearable devices, and related fields.

Liquid-Phase Exfoliation of 3D Metal-Organic Frameworks into Nanosheets.

Traditionally, the acquisition of 2D materials involved the exfoliation of layered crystals. However, the anisotropic bonding arrangements within 3D crystals indicate they are mechanically reminiscent of 2D counterparts and could also be exfoliated into nanosheets. This report delineates the preparation of 2D nanosheets from six representative 3D metal-organic frameworks (MOFs) through liquid-phase exfoliation. Notably, the cleavage planes of exfoliated nanosheets align perpendicular to the direction of the minimum elastic modulus (Emin) within the pristine 3D frameworks. The findings suggest that the in-plane and out-of-plane bonding forces of the exfoliated nanosheets can be correlated with the maximum elastic modulus (Emax) and Emin of the 3D frameworks, respectively. Emax influences the ease of cleaving adjacent layers, while Emin governs the ability to resist cracking of layers. Hence, a combination of large Emax and small Emin indicates an efficient exfoliation process, and vice versa. The ratio of Emax/Emin, denoted as Amax/min, is adopted as a universal index to quantify the ease of mechanical exfoliation for 3D MOFs. This ratio, readily accessible through mechanical experiments and computation, serves as a valuable metric for selecting appropriate exfoliation methods to produce surfactant-free 2D nanosheets from various 3D materials.

A 3D SPH framework for simulating landslide dam breaches by coupling erosion and side slope failure

Depicting the co-occurrence of erosion and side slope failure during landslide dam breaches using numerical models remains a challenge. In this study, a 3D Smoothed Particle Hydrodynamics (SPH) framework is proposed by coupling the erosion and side slope failure processes. Erosion downcutting is depicted by calculating the washed-away materials due to shear forces exerted by overtopping flow, while side slope failure is simulated using the Drucker-Prager model. In the computation domain, the destabilized slope soil particles are identified, then set to deform like fluid, and subsequently mixed with the flow. The proposed model achieves a refined 3D simulation of breach channel morphology evolution. According to the driving factors, the breaching process can be divided into two stages: the erosion-dominated breach deepening stage, and the simultaneous deepening and widening stage driven by both erosion and side slope failure. Dam erodibility affects the rate of breaching, while soil cohesion influences the breach channel evolution. As soil erosion rate increases, peak discharge increases following a power function, while peak timing decreases according to a power function. As soil cohesion increases, side slope failure slows, resulting in steeper slopes and more pronounced “headcut” erosion, which shifts the slope failure mode from sliding to collapsing.

Exploring optimal Li composite electrode anodes for lithium metal batteries through in situ X-ray computed tomography

The uncontrolled Li dissolution/deposition dynamics and rapid Li pulverizations hinder the widespread deployment of Li metal batteries (LMB). Designing a Li composite electrode possessing a mechanically robust and lithiophilic three-dimensional (3D) framework represents a promising strategy to address these challenges. This study involves the preparation of three uniquely tailored Li-B-Mg composites using a combined metallurgical process of melting, casting, and rolling, along with the synergistic application of in situ X-ray computed tomography (CT) and post-mortem failure analysis to explore the most promising composite electrode candidate for LMBs. During the in-depth investigation, the optimal 70Li-B-Mg composite electrode stands out due to its robust skeleton fiber structure, uniform Li dissolution/deposition characteristics and high capacity of free-Li. Its promising prospects for enabling high-performance LMBs are showcased by the superior performance of the built Li||O2, Li||LiFePO4, Li||NCM622 and Li||NCM811 battery systems. This work offers a novel approach for exploring universally applicable and robust Li composite electrodes to realize high-performance LMBs using in situ CT analysis.

Rational design of continuous and short-range lithium ion pathways based on polydopamine-anchored metal-organic frameworks for all-solid-state electrolytes

The immerging three dimensional (3D) metal-organic framework (MOF)-reinforced composite solid-state electrolytes have attracted great interest because of the enhanced ionic conductivity and mechanical properties. However, the defective spatial arrangement of MOFs restricted by fabrication methodology leads to insufficient lithium ion transport in electrolytes. Herein, a 3D interconnected MOF framework tailored for all-solid-state electrolytes is rationally designed by a universal polydopamine (PDA)-engineered “double-sided tape” strategy. The PDA serves as a double-sided tape, firmly adhering on the special single-layer Nylon grid as well as offering uniform nucleation sites to anchor the metal nodes to ensure continuous growth of well-ordered MOFs. Benefiting from the Lewis acid feature of MOFs and its cage effect toward TFSI−, a fast and homogeneous lithium ion transport can be achieved through the internal channels within neighboring MOFs and the continuous MOFs/polymer interfaces both along the short-range circumferential boundary of Nylon fiber. The resultant composite electrolytes exhibit high lithium ion conductivity and prominent mechanical properties, rendering excellent cyclic stability whether used in coin or pouch cells. This work demonstrates a widely applicable “double-sided tape” strategy for controllable spatial arrangement of MOF nanoparticles on optional substrates, which provides a scalable approach to rationally construct desired lithium ion pathways within composite electrolytes.