Homogeneous Structure Research Articles

Soybean protein isolate/dialdehyde sodium alginate hydrogels based on dynamic imine bond cross-linking: Synthesis and properties.

A soybean protein isolate (SPI)-based hydrogel with controllable properties was prepared under mild conditions using a simple mixing method with dialdehyde sodium alginate (DSA) as an eco-friendly macromolecular crosslinker. DSA was successfully synthesized via periodate oxidation. Analysis of the structure of the SPI/DSA hydrogel indicated that a 3D network was formed between SPI and DSA through dynamic imine and hydrogen bonds. The analysis of the physicochemical properties of the hydrogels showed that the micropore size, mechanical properties, and the swelling and release behavior of the hydrogels could be effectively regulated by changing the DSA content. When 3.0wt% DSA was added, the hydrogel exhibited a dense and homogeneous network structure with optimal gel properties, which enabled the controlled release of curcumin. This effective structure is mainly attributed to the synergistic effect of short- and long-range chemical and physical crosslinking. Overall, the SPI/DSA hydrogels are effective carriers for the controlled release of bioactive compounds.

Noncollinear phase of the antiferromagnetic sawtooth chain

The antiferromagnetic sawtooth chain is a prototypical example of a frustrated spin system with vertex-sharing triangles, giving rise to complex quantum states. Depending on the interaction parameters, this system has three phases, of which the gapless noncollinear phase (for strongly coupled basal spins and loosely attached apical spins) has received little theoretical attention so far. In this work, we comprehensively investigate the properties of the noncollinear phase using large-scale tensor network computations which exploit the full SU(2) symmetry of the underlying Heisenberg model. We study the ground state both for finite systems using the density-matrix renormalization group (DMRG) as well as for infinite chains via the variational uniform matrix-product state (VUMPS) formalism. Finite temperatures and correlation functions are tackled via imaginary or real time evolutions, which we implement using the time-dependent variational principle (TDVP). We find that the noncollinear phase is characterized by a low-momentum peak and a diffuse tail for the apex-apex correlations. Deep into the phase, the pattern sharpens into a peak indicating a 90∘ spiral. The apical spins are soft and highly susceptible to external perturbations; they give rise to a large number of gapless magnetic states that are polarized by weak fields and cause a long low-temperature tail in the specific heat. The dynamic spin-structure factor exhibits additive contributions from a two-spinon continuum (excitations of the basal chain) and a gapless peak at k=π/2 (excitations of the apical spins). Small temperatures excite the gapless states and smear the spectral weight of the k=π/2 peak out into a homogeneous flat-band structure. Our results are relevant, e.g., for the material atacamite Cu2Cl(OH)3 in high magnetic fields. Published by the American Physical Society 2025

Polyhydroxybutyrate as a Novel Biopolymer for Dental Restorative Materials: Biological and Morphological Analysis

Polyhydroxybutyrate (PHB) is a biopolymer produced by bacteria. This study aimed to implement the production process of experimental medical-grade PHB and to evaluate its morphology and biocompatibility compared to conventional resin-based composites (RBCs). PHB raw material was produced via biological process and then the membrane was generated via electrospinning specifically for this study and imaged with Micro-Computed Tomography (Micro-CT) and scanning electron microscopy (SEM). MTS assay was used to assess the cytotoxicity of PHB compared to other materials. Test groups included two packable resin composites (Point 4-Kerr, G-aenial anterior-GC), two flowable resin composites (Filtek Ultimate Flowable-3M ESPE, Nova Compo HF-Imicryl), a compomer (Nova Compomer-Imicryl), a fissure-sealant (Fissured Nova Plus-Imicryl), and the PHB membrane (Innovaplast Biotechnology Inc., Eskisehir, Turkey). A control group consisting of cells without any test material was also produced. To perform the MTS assay, disc-shaped specimens of the aforementioned materials were prepared and then incubated with mouse fibroblast cells (L929) for 24 and 48 h. Micro-CT and SEM images revealed a homogeneous and fibrillary structure of the PHB. MTS assay revealed the highest cell viability in the PHB, Nova Compomer, and Fissured Nova Plus groups after 24 h. PHB and Nova Compomer showed the highest viability rates at 48 h while other RBCs had rates below 25% (p < 0.05). Considering the cell viability data and its fibrillary structure, from a biological point of view, PHB seems a promising biopolymer that might have applications in the field of dental restorative materials.

Developing Orthogonal Fluorescent RNAs for Photoactive Dual‐Color Imaging of RNAs in Live Cells

AbstractFluorogenic RNA aptamers have revolutionized the visualization of RNAs within complex cellular processes. A representative category of them employs the derivatives of green fluorescent protein chromophore, 4‐hydroxybenzlidene imidazolinone (HBI), as chromophores. However, the structural homogeneity of their chromophoric backbones causes severe cross‐reactivity with other homologous chromophores. This limitation impairs their multiplexing capabilities, which are essential for the simultaneous visualization of multiple RNA species in live cells. Herein, we rationally designed a series of red‐shifted chromophores and employed SELEX‐independent engineering to develop a novel fluorogenic RNA aptamer, mSquash. mSquash displays specific and intense fluorescence upon binding with our red‐shifted chromophore DFHBFPD (Ex/Em=501/624 nm). The mSquash/DFHBFPD allows orthogonal imaging of selected RNA targets alongside the established Broccoli/DFHBI‐1T (Ex/Em=472/501 nm), facilitating multiplexed live cell imaging of various targets. Moreover, we expanded the application of fluorescent RNA to photoactive imaging by constructing two genetically encoded photoactivatable fluorescent RNAs for the first time. This innovative approach allows photoactivatable control of fluorescent RNAs via specific light wavelengths (365 nm and 450 nm), enabling spatiotemporal dual‐color imaging of RNAs in live cells. Our findings represent a significant advancement in fluorescent RNA‐based orthogonal imaging and spatiotemporal analysis of RNAs.

Improving the N-glycosylation occupancy of plant-produced IgG1 by engineering the amino acid environment at Asn297

Monoclonal antibodies are crucial recombinant biopharmaceuticals, with N-glycosylation at Asn297 essential for their functionality. Plants are increasingly used for antibody production, achieving high expression levels and enabling glycoengineering to produce homogenous human-like N-glycan structures. However, plant-produced human IgG1 often shows significant underglycosylation with potential adverse effects for immune functions and stability. This study addressed this limitation of the widely used plant-based expression platform Nicotiana benthamiana by employing protein engineering to enhance N-glycosylation occupancy in plant-produced IgG1. This was achieved through an amino acid mutation near the conserved glycosylation site in the CH2 domain of the heavy chain. The transient expression of trastuzumab and SARS-CoV-2 neutralizing IgG1 antibody COVA2-15 in N. benthamiana, with mutations such as Y300L, resulted in a notable improvement in glycosylation occupancy. While the structural integrity and monodispersity of the IgG1 variant remained unaltered, an improvement in thermal stability was observed. Furthermore, functional assays showed that antigen binding and human hFcRn interaction were unaffected, while FcγRIIIa binding affinity increased. These findings demonstrate the potential of protein-engineering to enhance the quality and functionality of plant-produced IgG1 antibodies, making them comparable to mammalian-produced counterparts.

Preparation of halloysite nanotube-based monolithic column for small molecules and protein analysis.

s: This study aimed to prepare a new separation medium, silane coupling agent KH570- modified halloysite nanotube (MPS-HNT) monolithic column, with excellent separation performance for small molecular compounds and macromolecular proteins. This was prepared using the principle of redox polymerization with modified HNTs as monomers. The optimal monomer proportion was obtained by optimizing the ratio of monomer, cross-linker, and pore-forming agent, which was evaluated using scanning electron microscopy, nitrogen adsorption, and mercury intrusion. The monolithic column exhibited a relatively homogeneous pore structure and good separation performance and permeability. As a high-performance liquid chromatography stationary phase, six small aromatic molecules were successfully separated in 6min with a theoretical plate count of 35, 640 plates m-1 for benzene. Twenty-one peaks were separated from the fermentation mattress extract containing lipopeptide antibiotics on the MPS-HNT column. The separated chromatographic peaks further identified three lipopeptide antibiotics using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis. Twelve chromatographic peaks were isolated from chicken egg whites, and the eighth peak was identified as the lysozyme. The methodological validation of the lysozyme in chicken egg white showed that the linear correlation coefficient was 0.9996. The intraday and inter-day relative standard deviations were 3.1-4.0% and 1.9-3.4%, respectively. The spike recovery rate of lysozyme was 94.20-103.31%. The overall column displayed good stability: the relative standard deviations of the peak area of six aromatic compounds and retention time were<3.28%.

Homogeneous Structures and Homogeneous Geodesics of the Hyperbolic Oscillator Group

In this paper, we study some homogeneity properties of a semi-direct extension of the Heisenberg group, known in literature as the hyperbolic oscillator (or Boidol) group, equipped with the left-invariant metrics corresponding to the ones of the oscillator group. We identify the naturally reductive case by the existence of the corresponding special homogeneous structures. For the cases where these special homogeneous structures do not exist, we exhibit a complete description of the homogeneous geodesics.

Femtosecond-Laser-Ablated Porous Silver Nanowire Heater with Ultralow Driven-Voltage and Ultrafast Sensitivity for Highly Efficient Crude Oil Remedy.

The development of viscous-crude oil and water separation technology is important for overcoming pollution caused by oil spills. Although some separators responding to light, electric, and temperature have been proposed, their poor structural homogeneity and inferior controllability, together with weak capillary forces, hinder the rapid salvage of viscous crude oil. Herein, a Joule-heated hydrophobic porous oil/water separator is reported, which has advantages of low energy consumption (169.7 °C·cm2·W-1), short thermal-response time (5 s) and rapid heating rate (13 °C/s). Under an ultralow voltage of 4.5 V, crude oil could infiltrate through the separator within 5 s. COMSOL simulation reveals the thermodynamics of crude oil's unidirectional collection. Significantly, the gradient wettability originating from the asymmetrical temperature on the dual face is the dominant driving force for efficient oil/water separation. Finally, a homemade device is successfully deployed for continuous viscous oil/water separation. This work provides a new avenue for viscous oil remedy.

Removal of malachite green dye by adsorption onto chitosan‐montmorillonite nanocomposite: Kinetic, thermodynamic and equilibrium studies

AbstractIn this study, the efficiencies of chitosan, montmorillonite, and chitosan/montmorillonite composites in various ratios for the removal of malachite green dye from aqueous solutions were investigated, and their maximum adsorption capacities were compared, and the effects of factors such as composite concentration, pH, contact time, dye concentration, and temperature were examined. Recovery attempts using different chemicals were also performed. Adsorption was analyzed using Langmuir and Freundlich isotherm models, and thermodynamic analyses were conducted. Fourier‐transform infrared (FTIR) and scanning electron microscopy (SEM) analyses were used to investigate surface changes. The highest adsorption capacity was found for the 20% chitosan/montmorillonite composite (400 mg g−1). Temperature studies indicated a decrease in adsorption capacity with increasing temperature. Kinetic studies observed that the data fit the pseudo‐second‐order kinetic model better. In recovery attempts, more than 95% recovery was achieved with HNO3 and HCl. FTIR results showed that chitosan–montmorillonite interactions involved ‐NH, ‐OH, C=O, and C‐O bonds, while dye binding was mainly through OH bonds. SEM analysis revealed that montmorillonite reduced surface cracks and roughness, creating a more homogeneous structure, and more rough areas appeared after dye binding. As a result, the chitosan/montmorillonite composite significantly enhanced dye adsorption capacity.

Fly ash-cement compositions modified by complex sulfate- carbonate admixture and fine grained concretes on their basis

Abstract. The article is devoted to the study of dispersed reinforced fine-grained concrete, based on modified fly ash-cement binders, containing at least 55% by weight of fly ash. The use of the developed binder will allow the utilization of waste from the fuel and energy industry in the composition of fine-grained concrete, on the one hand, and on the other hand, it will reduce emissions of carbon dioxide into the atmosphere by reducing the consumption of OPC clinker in the composition of binders. In the course of the research, the positive effect of the complex modification of the fly ash-cement composition with sulfate and carbonate additives was proven, and the phase composition of new formations of artificial stone was studied. It was found that during the simultaneous modification of the fly ash-cement composition, the synthesis of strength is ensured due to the formation of hydration products in the early stages of hardening of ettringite and its analogues with a carbonate and iron component. The operational and technological properties of the developed binders and concrete based on them were studied. In the process of studying the atmospheric resistance of the developed compositions based on modified binders, a stable increase in strength by 13...15% was established after 350 cycles of alternating wetting and drying of fine-grained concrete samples, which indicates the continuation of the processes of structure formation in artificial stone and allows predicting high operational properties of developed materials. It was found that the developed fine-grained concretes based on modified ash-containing binders are distinguished by a denser and more homogeneous structure of artificial stone, as evidenced by a decrease in the abrasion indicators of concretes based on modified systems by 50% and by 54.8% for dispersion-reinforced concrete compared to additive-free compositions, respectively. The durability of the developed concrete compositions was studied by studying their kinetics of strength gain, wear, frost, atmospheric and corrosion resistance. It was established that the introduction of a sulfate-carbonate additive to the composition of fly ash-cement systems contributes to a more uniform set of strength of concrete at all stages of hardening. The increase in strength of modified concrete samples is: at the age of 7 days – 105.88%, at the age of 28 days – 141.17% and at the age of 90 days – 117.53%, the value of compressive strength is 8.05, respectively MPa, 24.6 MPa and 33.5 MPa

Developing Orthogonal Fluorescent RNAs for Photoactive Dual-Color Imaging of RNAs in Live Cells.

Fluorogenic RNA aptamers have revolutionized the visualization of RNAs within complex cellular processes. A representative category of them employs the derivatives of green fluorescent protein chromophore, 4-hydroxybenzlidene imidazolinone (HBI), as chromophores. However, the structural homogeneity of their chromophoric backbones causes severe cross-reactivity with other homologous chromophores. This limitation impairs their multiplexing capabilities, which are essential for the simultaneous visualization of multiple RNA species in live cells. Herein, we rationally designed a series of red-shifted chromophores and employed SELEX-independent engineering to develop a novel fluorogenic RNA aptamer, mSquash. mSquash displays specific and intense fluorescence upon binding with our red-shifted chromophore DFHBFPD (Ex/Em=501/624 nm). The mSquash/DFHBFPD allows orthogonal imaging of selected RNA targets alongside the established Broccoli/DFHBI-1T (Ex/Em=472/501 nm), facilitating multiplexed live cell imaging of various targets. Moreover, we expanded the application of fluorescent RNA to photoactive imaging by constructing two genetically encoded photoactivatable fluorescent RNAs for the first time. This innovative approach allows photoactivatable control of fluorescent RNAs via specific light wavelengths (365 nm and 450 nm), enabling spatiotemporal dual-color imaging of RNAs in live cells. Our findings represent a significant advancement in fluorescent RNA-based orthogonal imaging and spatiotemporal analysis of RNAs.

Underwater sound absorption characteristics of the acoustic metamaterials with multiple coupling substructure

The lateral plates are usually used in the field of structural design of acoustic metamaterials (AMs), which can realize the control of AMs on sound waves. Presently, researches on the application of AMs with lateral plates mainly focus on the regulation of sound waves in air media, and rarely involve the research on their underwater acoustic properties. Therefore, a composite acoustic structure is designed by inserting regularly distributed lateral plates into the viscoelastic rubber, and then, the AMs with multiple coupling substructure (AMs-MCS) can be obtained through combining the local resonance structure and functional gradient structure. Based on underwater acoustic calculation model for the functional gradient acoustic structure established by grade finite element method (G-FEM), the underwater sound absorption characteristics of the AMs-MCS are studied, and the influence of each substructure on the acoustic performance of the AMs-MCS is explored. Numerical results indicate inserting gradient-distributed multiple lateral plates inside the homogeneous acoustic structure can improve the sound absorption performance of the acoustic structure in the mid-and high-frequency ranges and the sound absorption frequency band of the acoustic structure can be effectively broadened. Moreover, the sound absorption coefficient of the AMs-MCS is greater than 0.8 at 500Hz-10 kHz, and the average sound absorption coefficient reaches 0.893, thus achieving low-frequency and broadband sound absorption performance.

Effect of curing heating rate on tensile/flexural properties of carbon fiber reinforced plastic filament wound structure

The curing heating rate is a crucial component influencing the characteristics and curing effect of carbon fiber composites during the molding of carbon fiber reinforced plastic filament wound (CFRP FW). To investigate the relationship between the curing heating rate and CFRP FW’s mechanical and microstructure characteristics, in this study, carbon fiber composites the Navy Ordnance Laboratory (NOL) composite rings and unidirectional plates were prepared with five curing heating rates using wet filament winding, and the specimens were tested in tensile, flexural, and shear. Energy dispersive spectroscopy (EDS) was utilized to analyze the microstructural phases elementally, while scanning electron microscopy (SEM) was employed to characterize the shear section and fracture morphology of the unidirectional plate shear specimens. The findings demonstrated that at a curing heating rate of 2°C/min, the peak tensile strength of 2.26 GPa for NOL rings, 2.28 GPa for unidirectional plates, 38.91 MPa for shear strength, and 32.54 MPa for flexural strength were attained. The microfracture of the shear specimen has a uniform morphology, homogeneous structure, and the highest content of carbon elements. This work provides a way to control the pace of curing heating in order to improve the physical characteristics of fiber-woven parts.

Oyster Shell Powder/PCL Composite Scaffolds Loaded with Psoralen Nanospheres Promote Large Bone Defect Repair.

Research on bone substitutes for repairing bone defects has drawn increasing attention, and the efficacy of three-dimensional (3D) printed bioactive porous scaffolds for bone defect repair has been well documented. Our previous studies have shown that psoralen can promote osteogenesis by activating the Wnt/β-catenin and BMP/Smad signaling pathways and their crosstalk effects, and psoralen nanospheres have a good osteogenesis-promoting effect in vitro with low cytotoxicity. The Chinese medicine oyster shell powder, characterized by its porous structure, strong adsorption, and unique bioactivity, has potential in fracture-promoting repair materials. However, the effect of loading psoralen nanospheres onto oyster shell powder/polycaprolactone (OSP/PCL) scaffolds to repair bone defects is unclear. In this study, composite scaffolds consisting of OSP PCL were prepared by 3D printing, and psoralen nanospheres were adhered to the scaffolds. The characterization features of the composite scaffold system were investigated in vitro concerning the biocompatibility of bone mesenchymal stem cells (BMSCs). The efficacy of the composite scaffolds for repairing bone defects was explored in vivo through a rat cranial bone defect model. The results showed that the composite scaffolds were homogeneous porous structures with high mechanical strength and could be adhered well by the psoralen-loaded nanospheres. In vitro studies showed that the scaffolds had good biocompatibility with BMSCs and positively affected the expression of osteogenic differentiation-related proteins. In vivo studies showed that the composite scaffolds could more effectively promote the formation of new bone in the defect area (Φ5 mm) compared to the pure PCL scaffolds. At the same time, the composite scaffolds containing psoralen had a more significant stimulating effect on the healing of the cranial defects compared with the OSP/PCL scaffolds without psoralen.

Ultrahigh Energy Storage Performance in BiFeO3-Based Lead-Free Ceramics via Tuning Structural Homogeneity and Domain Engineering Strategies.

Lead-free ceramic-based dielectric capacitors are critical in electronics and environmental safety. Nevertheless, developing ideal lead-free ceramics with excellent energy storage properties remains a challenging task for practical applications. Herein, the enhanced relaxation behavior and increased breakdown electric field are utilized to realize the high energy storage behavior of (0.7-x)BiFeO3-0.3BaTiO3-x(Na0.7Sm0.1)NbO3(BF-BT-xNSN) ceramics. The introduction of complex perovskite compound NSN facilitates the transition of domains to nanodomains and improves the homogeneity of the microstructure, which results in the enhancement of the relaxation properties and breakdown electric field. Hence, the BF-BT-0.2NSN ceramic can achieve an ultrahigh energy storage density of 13.1 J/cm3 under an electric field of 650 kV/cm. Moreover, the designed BF-BT-0.2NSN ceramic achieves remarkable thermal stability (20-100 °C), frequency stability (1-100 Hz), and excellent charge/discharge performance. This study develops an idea of dielectric capacitor design and reveals the remarkable potential of BiFeO3-based dielectric ceramics within the realm of energy storage applications.

On 3-nondegenerate CR manifolds in dimension 7 (I): The transitive case

Abstract We investigate 3-nondegenerate CR structures in the lowest possible dimension 7, and one of our goals is to prove Beloshapka’s conjecture on the symmetry dimension bound for hypersurfaces in C 4 \mathbb{C}^{4} . We claim that 8 is the maximal symmetry dimension of 3-nondegenerate CR structures in dimension 7, which is achieved on the homogeneous model. This part (I) is devoted to the homogeneous case: we prove that the model is locally the only homogeneous 3-nondegenerate CR structure in dimension 7.

Physical simulation of separating two immiscible liquids in the “Pobeda” smelting unit with localized melt sparging by means of side and basal tuyeres

The paper aims to find physicochemical patterns in the separation of liquid smelting products with the melt blasted by side and basal tuyeres installed in the area of a “Pobeda” smelting unit intended for charging and melting copper-containing charge. The study adopted the physical simulation method with the use of transparent media (vegetable oil and colored water) and a glass cuvette. The dynamic similarity between the sample and model was ensured by the constancy of the Archimedes number Ar. The initial ratio between the levels of less and more dense fluids was chosen according to the Weber number We. The Archimedes numbers per one side and one basal tuyere amounted to 5;3 and 12;6 (Variants 1 and 2, respectively). The completeness of phase separation was determined visually through filming the liquid-liquid interface emergence and the settlement front advance, as well as quantitatively via the sampling method with subsequent separation of water and oil through centrifugation. According to the condition Ar = idem, the blasting parameters were determined for the cold model with the installation of six basal and three side tuyeres, which were assumed to be located in the sparging zone of the melt. The phase separation patterns are shown to depend on the duration and intensity of the blast. Under Variant 1, blasting is characterized by the formation of a constant phase immiscibility profile at the end of the experiment, which occurs in a limited area of the settlement zone that is far from the sparging zone. At higher Archimedes numbers (Variant 2), the melt pool acquires a homogeneous structure in a shorter time, and no immiscibility boundaries are observed along the entire length of the melt. Thus, a cold modeling technique was developed to study the patterns of phase separation in the presence of a separate sparging zone in the melt pool. This provides a means to obtain objective parameters for the location of tuyeres and blasting conditions, thus ensuring a reduction in the mechanical losses of copper with slag at a given smelting capacity in the “Pobeda” unit.

Memory Effect of Double Oxides Compared to Simple Ion Exchange for Controlled Fluoride Ion Capture and Release

A layered double hydroxide (LDH) containing Mg and Al was synthesized from a nitrate solution using a coprecipitation method. The resulting material exhibited a homogeneous structure, which, upon calcination at 450 °C, was converted into a layered double oxide (LDO). When rehydrated in a fluoride-containing aqueous solution, the original hydroxide structure was successfully regenerated, demonstrating the LDH’s memory effect. During this transformation, fluoride anions from the solution were incorporated into the interlayer galleries to maintain electroneutrality, as confirmed by energy-dispersive X-ray spectroscopy (EDS) analysis. Separately, the process was tested in the presence of ethanol, which significantly enhanced the incorporation of fluoride ions into the interlayer spaces. The material’s potential for controlled fluoride release was evaluated by monitoring its release into demineralized water. For comparison, a simple ion-exchange process was carried out using the as-synthesized MgAl LDH. The memory effect mechanism displayed a notably higher fluoride incorporation capacity compared to the ion-exchange process. Among all the specimens, the sample reconstructed in the presence of ethanol exhibited the highest fluoride ion content. Fluoride release studies revealed a two-phase pattern: an initial rapid release within the first three hours, followed by a substantially slower release over time.

Mechanisms of interlayer friction in low-dimensional homogeneous thin-wall shell structures and its strain effect.

Due to the multi-factor coupling effect, the rule of interlayer friction in low-dimensional homogeneous thin-wall shell structures is still unclear. Double walled carbon nanotubes (DWCNTs) having a typical low-dimensional homogeneous thin-wall shell structure are selected for this study. The interlayer friction of numerous chiral DWCNTs is investigated using molecular dynamics simulations to systematically analyze and understand the coupling mechanisms of various factors in interlayer friction. To eliminate the influence of the edge effect, a high-speed pure rotation model is used. The results demonstrate that DWCNTs with varying mismatch angle, interlayer distance, and interfacial radius exhibit distinct interlayer frictions and strain effects, due to the differences in interlayer interaction, atomic vibrational amplitudes, and lattice periods. Theoretical analysis is conducted on the interlayer friction and its strain effect based on the theoretical model. Based on phonon spectrum analysis, the vibrational modes and energy dissipation of DWCNTs with different chiral combinations under various strains are demonstrated. Based on the analysis, physical insight into the variation in friction forces is provided. The findings of this work deepen the understanding of the interlayer friction and strain mechanism and provide a theoretical basis for further exploitation of the strain effect to realize the regulation of nanoelectromechanical devices.

Superior mechanical properties of an additively manufactured gradient lattice structure through FEM simulation and in-situ compression tests

Currently, the increasing incidence of bone defects and damage due to diseases and trauma, the treatment of bone defects usually uses autologous bone graft or allogeneic bone graft, however, the amount of autologous bone is limited, and there is also the risk of infection at the site of bone extraction, and allogeneic bone graft also faces problems such as disease transmission and immune rejection. In summary, artificial bone provides a new option for patients. This study investigates the mechanical properties of homogeneous and gradient Gyroid and Diamond porous structures, designed with average porosities of 50%, 60%, and 70%, using triply-periodic minimal surface models for artificial joints. Finite Element Method simulations and compression tests were employed to characterize the mechanical properties of Ti6Al4V porous scaffolds fabricated using the selective laser melting technique. The measured elastic modulus of the scaffolds ranged from 6.24 to 10.5GPa, meeting the requirements for orthopedic implants. Gyroid structures were shown to exhibit superior nominal stiffness compared to Diamond structures at equivalent porosity levels. Furthermore, the linear gradient porous structures demonstrated significantly higher elastic modulus, yield strength, and compressive strength compared to homogeneous porous structures, with increases of 66.9%, 20.3%, and 16.5%, respectively. The energy absorption capacity of the linear gradient porous structure was also found to be 3.3-fold greater than that of the homogeneous structure.The lightweight design of this linear gradient porous structure provides the basis for bone implants for biomedical applications.