Growth Mechanism Research Articles

Energetic and structural stability of vacancy clusters in Al under external stress conditions

In this study, we investigated the structural stability and energetic behavior of void-type, plate-like, and stacking fault tetrahedra (SFT) vacancy clusters in Al under varying tensile and compressive stress conditions. Our results demonstrate that void-type and plate-like clusters maintain their structures under tensile stress, which energetically favors the aggregation and growth of isolated vacancies. However, compressive stress induces structural transitions in these clusters, reducing their stability. In contrast, SFT clusters retain their characteristic configuration under both tensile and compressive stress. While compressive stress promotes SFT formation and growth, tensile stress hinders vacancy aggregation, making SFTs less stable under tension. Comparatively, SFT clusters are the most stable under compressive stress, while void-type clusters become the most stable under high tensile stress. These findings provide critical insights into the stress-dependent behavior of vacancy clusters, with implications for defect engineering in materials subjected to external stress, offering a deeper understanding of vacancy cluster stability and growth mechanisms across different stress regimes.

High efficiency microwave absorption properties of α−SiCp/α−SiCnw/SiO2/C composites with multi−interface hybrid SiC nanowires prepared by heterogeneous nucleation−growth mechanism

High efficiency microwave absorption properties of α−SiCp/α−SiCnw/SiO2/C composites with multi−interface hybrid SiC nanowires prepared by heterogeneous nucleation−growth mechanism

Non-intrusive experiments on coupled bubble dynamics and heat transfer during nucleate boiling under varying pressure conditions

The experimental investigation is concerned with the dynamics of single vapor bubble and heat transfer during nucleate boiling under varying pressure conditions, encompassing both atmospheric and sub-atmospheric levels. Utilizing high-speed rainbow schlieren deflectometry, a non-intrusive imaging technique for visualizing and quantifying the flow field variables in the fluid medium, this research examines the influence of operating pressure on some of the important parameters pertaining to boiling phenomenon such as bubble size, shape, and detachment mechanisms. The observations show that a decrease in pressure leads to the formation of larger bubbles, which, in turn, alters their growth mechanism. These changes in bubble behavior have a significant influence on the various forces acting on the growing bubble as well as on the associated heat transfer rates. The analysis provides insights into the complex interplay between buoyancy, surface tension, growth and contact pressure forces. Change in pressure significantly impacts these forces, influencing bubble dynamics. Moreover, the study presents a quantitative analysis of the whole field temperature distribution and heat transfer rates throughout the boiling process. Results reveal a strong dependence of thermal field on the working pressure, with higher pressures leading to more uniform temperature distributions. Evaporative component of heat transfer from the bubble base and convective heat transfer from the superheated layer are identified as the dominant mechanisms. Natural convection initially dominates, decreases post-nucleation, and increases upon bubble departure due to the fluid quenching effects.

Mechanics of finite nonlinear viscoelastic growth for soft biological tissues

Mechanics of finite nonlinear viscoelastic growth for soft biological tissues

Biosynthesis and Application of Biological Thin Films for Heavy Metal Ion Biosorption from Aqueous Solution

This study investigates the biosynthesis and application of Mycelium Bio-Films (MBFs) derived from pure Common oyster mushroom (COM) for heavy metal ion biosorption from aqueous solutions. The research focuses on the growth mechanism of MBFs and their potential for Cu (II) ions removal. MBFs were synthesized through a hyphae cultivation process and characterized using Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), and Energy-Dispersive X-ray Spectroscopy (EDS) mapping. Batch biosorption experiments were conducted to determine optimal operational parameters and adsorption mechanisms. Key findings reveal optimal biosorption conditions at pH 5, with a 40-minute contact time, and 100mg/L initial Cu (II) concentration using 0.2g of biosorbent in 10mL aqueous solution at room temperature with 150rpm agitation. Under these conditions, a maximum adsorption efficiency of 82.8% was achieved. The adsorption process best fits Pseudo-second-order kinetics and Langmuir isotherm, indicating chemisorption, complexation, and ion exchange as primary mechanisms. Functional groups involved in biosorption include carboxyl, hydroxyl, and amide groups. Importantly, MBFs demonstrate high reusability potential through diluted acid elution. This research contributes to environmental remediation by presenting a novel, sustainable biosorbent for heavy metal removal. The MBFs show promise for industrial wastewater treatment applications, offering an eco-friendly alternative to conventional adsorbents and contributing to filling the lack of biobank collections. Future studies could explore the efficacy of MBFs with other heavy metals and investigate potential scale-up for large-scale implementation.

Plant-inspired decentralized controller for robust orientation control of soft robotic manipulators.

Due to the complexity of deformations in soft manipulators, achieving precise control of their orientation is particularly challenging, especially in the presence of external disturbances and human interactions. Inspired by the decentralized growth mechanism of plant gravitropism, which enables plants' roots and stems to grow in the direction of gravity despite complex environmental interactions, this study proposes a decentralized control strategy for robust orientation control of multi-segment soft manipulators. This gravitropism-inspired decentralized controller was validated through simulations for convergence and robustness, and benchmarked against the traditional inverse Jacobian-based controller on a large-scale multi-segment soft manipulator. Experimental results demonstrate that the decentralized controller achieves comparable convergence and better control precision to the inverse Jacobian-based controller, while significantly outperforming it in disturbance rejection. Even in the presence of partial damage and human interaction, the decentralized controller provides robust control. This study provides a robust new approach for managing disturbances in complex environments, laying the foundation for further exploration of decentralized control strategies in soft robotics.

Effects of titanium oxide nanoparticles on growth, biochemical composition, and photosystem mechanism of marine microalgae Isochrysis galbana COR-A3

The widespread utilization of titanium oxide nanoparticles (TiONPs) in various industrial applications has raised concerns about their potential ecological risks in marine environment. Assessing the toxicity of TiONPs on primary producers is essential to understand their impact on marine ecosystem. This study investigates the acute toxicity effect of TiONPs on Isochrysis galbana COR-A3 cells, focusing on structural and physiological changes that can compromise algal viability and ecological function. Cells were exposed to TiONPs concentration of 10–50 mg/L and assessments were conducted over 96 h to evaluate cell viability, biochemical composition, photo-physiology, oxidative stress and morphological deformations. At 50 mg/L concentration, cell viability was significantly reduced by 73.42 ± 3.46% and subsequent decrease of 42.8%, 29.2%, 44.2% in carbohydrate, protein and lipid content were observed. TiONPs exposure elevates the reactive oxygen species production and thereby impairing the photosystem II efficiency and disrupting the cellular metabolism. Morphological analysis revealed significant cell membrane disruption and plasmolysis. These cascading effects reveal TiONPs ability to interfere with algal physiological process, potentially affecting the primary productivity in marine ecosystem. Our findings highlight the ecological risk associated with the TiONPs, emphasizing the need for regulatory measures to mitigate the nanoparticle pollution in aquatic environment. This study provides more insights on the TiONPs induced toxicity in marine microalgae by altering the photosynthetic performance and biochemical integrity.

Deciphering Mg-Surface Interactions with Unsaturated Hydrocarbons: An Integrated Experimental-Theoretical Study.

Here, we used a combination of laser-induced experiments and density functional theory (DFT) calculations to study the mechanism of growth of carbonaceous species on the Mg surface. Experimental observations revealed that the carbon deposit forms upon laser illumination on the Mg surface, with the deposit being clearer and better structured in the presence of 1,3-butadiene (C4H6) compared to ethylene (C2H4) gas. DFT thermodynamic and kinetic calculations of C2-C4 hydrocarbons interaction on low-index Mg(0001) were used to explain this experimental observation. Our results on Mg(0001) showed that the cis isomer of C4H6 binds more strongly than its trans isomer via a [4+2] cycloaddition mechanism. We also investigated the adsorption of two units of C2H4 and C4H6 molecules, as well as the subsequent dehydrogenation stages that produce radical species responsible for chain growth mechanisms. The results showed that free energy of dehydrogenation of two units of cis-C4H6 [i. e. cis-C8H12] is lower than the dehydrogenation of trans conformer of C4H6 and C2H4 molecule, indicating that the dehydrogenation of two units of cis-C4H6 facilitates the initiation of growth of carbonaceous species on Mg surfaces. Therefore, the DFT calculations pinpoint the origin of the experimental observation of clearer carbon deposits on the Mg surface.

Research on the growth mechanism of core innovation network of artificial intelligence industry based on valued ERGMs

ABSTRACT The analysis of the growth mechanisms within the core innovation network of the AI industry can reveal the current situation of collaboration relationship and clarify the law of technological evolution in China's AI field. Based on the invention patents of China's AI industry from 2014 to 2022, we constructed a multi-layer network including AI collaboration network and knowledge network. Then, we divided the AI industry into an initial exploration period, an accelerated advancement period and a mature development period according to the development stages. On this basis, we employed valued ERGMs to explore the weight of the relationship between the core collaboration network and the core knowledge network in different stages. The results show that organisational centrality and social proximity promote the growth of the AI industry collaboration network, while organisational knowledge diversity inhibits the growth of the AI industry collaboration network. Knowledge network centrality promotes the growth of the AI industry knowledge network, while knowledge uniqueness and knowledge maturity homogeneity inhibit the growth of the AI industry knowledge network. These findings enhance the study of multi-layer network evolution and valued ERGMs, while also offering valuable insights for the development of organisations within the AI industry.

Scalable Integration of High Sensitivity Strain Sensors Based on Silicon Nanowire Spring Array Directly Grown on Flexible Polyimide Films.

The growth and integration of position-controlled, morphology-programmable silicon nanowires (SiNWs), directly upon low-cost polymer substrates instead of postgrowth transferring, is attractive for developing advanced flexible sensors and logics. In this work, a low temperature growth of SiNWs at only 200 °C has been demonstrated, for the first time, upon flexible polyimide (PI) films, via a planar solid-liquid-solid (IPSLS) growth mechanism. The SiNWs with diameter of ∼146 nm can be grown into precise locations on PI as orderly array and with preferred elastic geometry. Strain sensor array, built upon these spring-shape SiNWs integrated on PI, achieves a gauge factor (GF) of ∼90, sustains large stretching strains up to 3.3% (with 1.5 mm radius) and endures over 30,000 cycles. Strain sensors attached to the finger to monitor movements are also successfully demonstrated, showing high sensitivity and superior mechanical reliability, particularly suited for wearable health applications.

Morphogenesis of Aragonite Biomineral Structures by the Nonclassical Colloidal Crystal Growth Mechanism Revisited on the Nanoscale: The Noah's Ark Shell (Arca noae, L.) Case Study.

Characterization and formation of the biomineral aragonite structures of the Noah's Ark shell (Arca noae L.,1758) were studied from structural, morphogenetic, and biochemical points of view. Structural and morphological features were examined using X-ray diffraction, field-emission scanning electron microscopy, and atomic force microscopy, while thermal properties were determined by thermogravimetric and differential thermal analyses. Proteins from the soluble organic matrix (SOM) were analyzed by Edman degradation. The results showed that the Noah's Ark shell exhibits several distinct biomineral structures characterized by complex morphologies and different forms of aragonite. The inner shell of the Ark is characterized by a combination of nanogranular surfaces and micron-sized, idiomorphically developed aragonite crystals indicative of orthorhombic symmetry. The formation of these structures is discussed in terms of the nonclassical crystal growth route considering the colloidally mediated mechanism based on the initial particle-particle interaction of the nanosized and metastable precursor aragonite phase and their dissolution and recrystallization processes. These structures contained a small amount of connecting organic material, SOM, assessed at 1.5% of the total mass. Edman degradation revealed the partial amino acid sequence that is present also in the tetratricopeptide repeat (TPR) protein 8 from diverse mussels. Bacterial TPR-containing protein was found to be involved in the biomineralization process, so we propose such a function for these proteins also in mussels.

Mechanistic Insights into the Formation of Dumbbell-Shaped Carbonate Minerals: A microscale study

Dumbbell-shaped carbonate minerals are widely recognized as a distinctive morphology induced by microorganisms. Understanding their morphological evolution and growth mechanisms is essential for elucidating bacterial-mediated carbonate mineralization processes. In this study, we used the mineralizing bacterium Curvibacter sp. strain HJ-1 to induce the formation of dumbbell-shaped carbonate minerals within a rapid crystallization system with a Mg/Ca ratio = 5. A range of microscale analytical techniques, including scanning electron microscopy, focused ion beam, and transmission electron microscopy, were employed to systematically investigate the morphological changes and crystallographic orientation of these minerals. The results reveal that the formation process involves the aggregation of Ca-Mg nanoparticles at both ends of the structure, with bacterial cells acting as a template. These findings offer preliminary insights into the formation mechanisms of dumbbell-shaped minerals and provide a scientific basis for biogenic analysis of field samples.

Organic Molecules Induce the Formation of Hopper-Like NaCl Crystals under Rapid Evaporation As Microcatalytic Reactors To Facilitate Micro/Nanoplastic Degradation.

As representative examples of inorganic ionic crystals, NaCl and KCl usually form cubes during the natural evaporation process. Herein, we report the hopper-like NaCl and KCl crystals formed on the iron surface under rapid vacuum evaporation aided by organic molecules. Theoretical and experimental results indicate that it is attributed to the organic molecules alternating adsorption between {100} and {110} surfaces instead of adsorbing a single surface, as well as the fast crystal growth rate. Following this law, we found hopper-like crystals formed under natural evaporation conditions in salt lake crystals as well as synthesized kilogram-class hopper-like crystals. Interestingly, the hopper-like crystals can act as microcatalytic reactors to efficiently facilitate micro/nanoplastic degradation with ∼91.72% styrene yield, highly decreasing the degradation temperature from ∼400 to ∼275 °C. These findings provide an understanding of the growth mechanism of various crystals and a friendly environmental, low-carbon, and economical microcatalytic reactor for efficient micro/nanoplastic degradation.

Effect of Hydration States on the Anti-Icing/Frosting Performance of Zwitterionic Hydrogel-Coated Surfaces.

Zwitterionic polymers have gained considerable research attention because of their unique properties and have been widely used in many biomedical and electrochemical applications. Recently, zwitterionic polymers have been investigated for use as anti-icing/frosting surfaces; however, key factors influencing their anti-icing/frosting performance and effectiveness under real operational conditions remain underexplored. Therefore, in this study, we quantitatively analyze the hydration states of zwitterionic hydrogels synthesized from polymerizable zwitterions, such as carboxybetaine methacrylate (CBMA), 2-methacryloyloxyethyl phosphorylcholine (MPC), and sulfobetaine methacrylate (SBMA). We focused on the effect of these hydration states on anti-icing/frosting performance in practical environments through a thermodynamic approach. The fractions of freezable water were 14% in pCBMA, 16% in pMPC, and 34% in pSBMA. The activation energy for ice formation within the hydrogel was observed as pCBMA (101.71 kJ mol-1) > pMPC (74.32 kJ mol-1) > pSBMA (59.82 kJ mol-1), suggesting that the zwitterionic hydrogel-coated surface makes ice formation more challenging compared to the uncoated bare substrate (45.79 kJ mol-1). We confirm that a reduction in the freezable water fraction within the hydration state can enhance the anti-icing/frosting performance. Our results demonstrate that zwitterionic hydrogels with strong interaction energies offer significant potential as anti-icing/frosting coatings. This work also reveals the in-depth mechanism of ice propagation and frost growth on hydrogel coatings and proposes insights that can be used to efficiently design future anti-icing/frosting coatings.

Soil Microbial Mechanisms to Improve Pear Seedling Growth by Applying Bacillus and Trichoderma-Amended Biofertilizers.

Bacillus velezensis SQR9 or Trichoderma harzianum NJAU4742-amended bioorganic fertilizers might significantly improve the soil microbial community and crop yields. However, the mechanisms these microorganisms act are far away from distinctness. We combined amplicon sequencing with culturable approaches to investigate the effects of these microorganisms on pear tree growth, rhizosphere nutrients and microbial mechanisms. The SQR9 and T4742 treatments increased the total biomass of pear trees by 68% and 84%, respectively, compared to the conventional organic fertilizer treatment (CK). SQR9 tends to increase soil organic matter and available phosphorus, while T4742 more effectively enhances nitrogen, potassium, iron and zinc levels. These effects were primarily linked to changes in the microbial community. T4742 treatment enriched twice as many differential microbes as SQR9. SQR9 significantly enriched Urebacillus, Streptomyces and Mycobacterium, while T4742 increased the abundance of Pseudomonas, Aspergillus and Penicillium. In vitro experiments revealed that secondary metabolites secreted by B. velezensis SQR9 and T. harzianum NJAU4742 stimulate the growth of key probiotics associated with their respective treatments, enhancing soil fertility and plant biomass. The study revealed the specific roles of these bioorganic fertilizers in agricultural applications, providing new insights for developing effective and targeted bioorganic fertilizer products and promoting sustainable agriculture.

Mesoporous Silica with Dual Stimuli-Microenvironment Responsiveness via the Pectin-Gated Strategy for Controlled Release of Rosmarinic Acid.

Traditional drug-delivery methods are limited by low bioavailability and nonspecific drug distribution, resulting in poor therapeutic efficacy and potential risks of toxicity. Mesoporous silica nanoparticles (MSNs) have attracted wide attention as drug-delivery carriers due to their large specific surface area, adjustable pore size, good mechanical strength, good biocompatibility, and rich hydroxyl groups on their surface. In this paper, MSNs were synthesized by a template method, and the morphology and pore structure were regulated. The obtained particles possessed a narrow particle size distribution and good sphericity with a diameter of 878 nm, and their growth process was consistent with the La-Mer growth mechanism. Furthermore, MSNs were modified with amino acids and loaded with rosmarinic acid (RosA), accompanied by the "outer packaging" of pectin to obtain RosA@MSNs-Pec. RosA was added at 200, 150, and 100 mg within 72 h, with a drug loading of 193, 175.5, and 156 mg/g and an encapsulation rate of 19.3, 17.6, and 15.6, respectively. Interestingly, RosA@MSNs-Pec demonstrated the dual pH and pectinase response property, and its release curve conformed to the Higuchi model, indicating that its drug-controlled release was based on Fick's law.

Catalytic Cu2O/Cu Site Trades off the Coupling and Etching Reactions of Carbon Intermediates for CO2-Assisted Graphene Synthesis.

In the chemical vapor deposition (CVD) synthesis of graphene, the surficial chemical state of the metal substrate has exerted key roles in all elemental reaction steps determining the growth mechanism of graphene. Herein, a CO2-participated annealing procedure is designed to construct catalytic Cu2O/Cu sites on Cu foil for the graphene CVD synthesis with CO2/CH4 as carbon sources. These Cu2O/Cu species can catalyze the CH4 decomposition and subsequent C─C coupling to form C2 intermediates for fast growth of monolayer hexagonal graphene domains with a diameter of ≈30µm within 0.5min. The graphene growth kinetics can be bidirectionally regulated merely with the variation of CO2 flow rate during annealing and growth stages, in association with the Cu+/Cu0 ratio, enabling simultaneous control over the size and shape of graphene domains. Density functional theory (DFT) calculations indicate that the catalytic Cu2O/Cu sites reduce the activation energy by ≈0.13eV for the first dehydrogenation of CH4, allowing the growing rate of graphene driven by coupling of C2 intermediates faster than their etching rate by O-containing *O and *OH species. The work provides novel insights into heterostructured nano-catalyst consisting of zero valent metal and variably valent metal oxide that facilitate the controllable synthesis of graphene materials.

Genome-Wide Identification and Expression Analysis of TCP Transcription Factors Responding to Multiple Stresses in Arachis Hypogaea L.

The TEOSINTE-BRANCHED1/CYCLOIDEA/PROLIFERATING-CELL-FACTOR (TCP) gene family, a plant-specific transcription factor family, plays pivotal roles in various processes such as plant growth and development regulation, hormone crosstalk, and stress responses. However, a comprehensive genome-wide identification and characterization of the TCP gene family in peanut has yet to be fully elucidated. In this study, we conducted a genome-wide search and identified 51 TCP genes (designated as AhTCPs) in peanut, unevenly distributed across 17 chromosomes. These AhTCPs were phylogenetically classified into three subclasses: PCF, CIN, and CYC/TB1. Gene structure analysis of the AhTCPs revealed that most AhTCPs within the same subclade exhibited conserved motifs and domains, as well as similar gene structures. Cis-acting element analysis demonstrated that the AhTCP genes harbored numerous cis-acting elements associated with stress response, plant growth and development, plant hormone response, and light response. Intraspecific collinearity analysis unveiled significant collinear relationships among 32 pairs of these genes. Further collinear evolutionary analysis found that peanuts share 30 pairs, 24 pairs, 33 pairs, and 100 pairs of homologous genes with A. duranensis, A. ipaensis, Arabidopsis thaliana, and Glycine max, respectively. Moreover, we conducted a thorough analysis of the transcriptome expression profiles in peanuts across various tissues, under different hormone treatment conditions, in response to low- and high-calcium treatments, and under low-temperature and drought stress scenarios. The qRT-PCR results were in accordance with the transcriptome expression data. Collectively, these studies have established a solid theoretical foundation for further exploring the biological functions of the TCP gene family in peanuts, providing valuable insights into the regulatory mechanisms of plant growth, development, and stress responses.

Competing pathways of intracranial aneurysm growth: linking regional growth distribution and hemodynamics.

The complex mix of factors, including hemodynamic forces and wall remodeling mechanisms, that drive intracranial aneurysm growth is unclear. This study focuses on the specific regions within aneurysm walls where growth occurs and their relationship to the prevalent hemodynamic conditions to reveal critical mechanisms leading to enlargement. The authors examined hemodynamic models of 67 longitudinally followed aneurysms, identifying 88 growth regions. These regions (of enlargement) were pinpointed through alignment and distance mapping between baseline and follow-up models. Aneurysm wall subdivisions were created based on saccular anatomy and flow-related characteristics, which were used to assess local hemodynamics. The distribution of growing regions across these subdivisions was then studied and stratified by aneurysm location and morphology to reveal distinct growth patterns. Statistical significance was evaluated using the Kruskal-Wallis and Mann-Whitney tests. Growth predominantly occurred in the body (p < 0.0001) of aneurysms, with anterior communicating artery (ACom) (p < 0.0001) and lateral (p = 0.002) aneurysms showing a significantly greater tendency for growth in this region. In comparison, middle cerebral artery (MCA) (p < 0.0001) and bifurcation (p = 0.0001) aneurysms demonstrated growth in both the dome and the body. Notable differences in growth distribution across saccular regions included ACom versus MCA (neck, p = 0.038), bifurcation versus lateral (neck, p = 0.008), and so forth. The central flow region saw the most growth (p < 0.0001); although not significant, ACom (p = 0.196) and lateral (p = 0.218) aneurysms showed a tendency for growth in inflow and central zones, while MCA (p = 0.001) and bifurcation (p < 0.0001) aneurysms were more likely to grow in the central flow region. Two primary mechanisms seem to influence aneurysm growth: high-flow impingement jets in the neck, body, and inflow zones leading to wall degeneration/thinning, mainly in ACom aneurysms; and slow, oscillatory flow conditions in the dome and central flow zones promoting wall remodeling/thickening, mainly in MCA aneurysms. This latter mechanism is also observed as secondary flows in ACom aneurysms. These findings emphasize the need to understand the distinct and sometimes concurrent mechanisms of aneurysm growth, advocating for targeted monitoring and interventions that mitigate rupture risks by considering the unique hemodynamic environments within different aneurysm regions and locations.

Interfacial Atomic Mechanisms of Single-Crystalline MoS2 Epitaxy on Sapphire.

The epitaxial growth of molybdenum disulfide (MoS₂)on sapphiresubstrates enables the formation of single-crystalline monolayer MoS₂ with exceptional material properties on a wafer scale. Despite this achievement, the underlying growth mechanisms remain a subject of debate. The epitaxial interface is critical for understanding these mechanisms, yet its exact atomic configuration has previously been unclear. In this study, a monolayer single-crystalline MoS₂ grown on a sapphire substrate is analyzed, decisively visualizing the atomic structure of the epitaxial interface and elucidating its role in epitaxial growth from an atomic perspective. The findings reveal that the interface consists of a periodic molecular MoO3 interlayer, van der Waals epitaxially grown on a single Al-terminated sapphire surface. Additionally, it is discovered that MoO3 coverage enhances surface interactions and introduces a unique atomic arrangement with 1-fold symmetry at the sapphire surface, thereby facilitating the unidirectional alignment of MoS₂. This discovery provides valuable insights into the growth mechanisms leading to single-crystalline MoS₂ formation, and suggests pathways for quantitatively monitoring and controlling growth dynamics, for the improvement of material quality and process repeatability, applicable for single-crystalline MoS₂ or potentially other transition metal dichalcogenides epitaxially grown on sapphire.