Fragmentation Mechanisms Research Articles

Digital green value co-creation behavior, digital green network embedding and digital green innovation performance: moderating effects of digital green network fragmentation

In the era of digital economy, digital green value co-creation behavior (DGVCB) has replaced the previous value creation. DGVCB has become a tool for business ecosystems to gain sustainable ecological advantages in today’s increasingly complex market. At present, there are few researches on the influence of DGVCB and digital green network embedding(DGNE) on digital green innovation performance(DGIP). This paper faces the institutional logic of DGVCB, analyzes the mechanism of DGNE and digital green network fragmentation (DGNF) in the context of business ecosystem competition, and then constructs the causal relationship between DGVCB and DGIP. Based on 326 valid questionnaires and sample data, this paper empirically studies the effects of digital green value co-creation and DGNE on DGIP by using regression analysis method, and verifies and discusses the proposed theoretical hypotheses. The results show that DGVCB and DGNE have significant positive effects on the improvement of DGIP. DGNE plays an intermediary role between DGVCB and DGIP. DGNF plays a positive moderating role between DGVCB and DGIP. This study provides theoretical guidance for the governance of business ecosystem and the formulation of cooperation strategies for enterprises.

Molecular mechanisms underlying TNFα-induced mitochondrial fragmentation in human airway smooth muscle cells.

Tumor necrosis factor α (TNFα), a proinflammatory cytokine, plays a significant role in mediating the effects of acute inflammation in response to allergens, pollutants, and respiratory infections. Previously, we showed that acute exposure to TNFα induces mitochondrial fragmentation in human airway smooth muscle (hASM) cells, which is associated with increased expression of dynamin-related protein 1 (DRP1). Phosphorylation of DRP1 at serine 616 (pDRP1S616) promotes its translocation and binding to the outer mitochondrial membrane (OMM) and mediates mitochondrial fragmentation. Previously, we reported that TNFα exposure triggers protein unfolding and triggers an endoplasmic reticulum (ER) stress response involving phosphorylation of inositol-requiring enzyme 1α (pIRE1α) at serine 724 (pIRE1αS724) and subsequent splicing of X-box binding protein 1 (XBP1s) in hASM cells. We hypothesize that TNFα-mediated activation of the pIRE1αS724/XBP1s ER stress pathway in hASM cells transcriptionally activates genes that encode kinases responsible for pDRP1S616 phosphorylation. Using 3-D confocal imaging of MitoTracker green-labeled mitochondria, we found that TNFα treatment for 6 h induces mitochondrial fragmentation in hASM cells. We also confirmed that 6 h TNFα treatment activates the pIRE1α/XBP1s ER stress pathway. Using in silico analysis and ChIP assay, we showed that CDK1 and CDK5, kinases involved in the phosphorylation of pDRP1S616, are transcriptionally targeted by XBP1s. TNFα treatment increased the binding affinity of XBP1s on the promoter regions of CDK1 and CDK5, and this was associated with an increase in pDRP1S616 and mitochondria fragmentation. This study reveals a new underlying molecular mechanism for TNFα-induced mitochondrial fragmentation in hASM cells.NEW & NOTEWORTHY Airway inflammation is increasing worldwide. Proinflammatory cytokines mediate an adaptive mechanism to overcome inflammation-induced cellular stress. Previously, we reported that TNFα mediates hASM cellular responses, leading to increased force and ATP consumption associated with increased O2 consumption, and oxidative stress. This study indicates that TNFα induces ER stress, which induces mitochondrial fragmentation via pIRE1αS724/XBP1s mediated CDK1/5 upregulation and pDRP1S616 phosphorylation. Mitochondrial fragmentation may promote hASM mitochondrial biogenesis to maintain healthy mitochondrial pool.

Uncovering the impact of sea mud-containing diet on fecal fragmentation and its potential environmental risks in recirculating aquaculture system of Apostichopus japonicus

A deep understanding of fecal characteristics and fragmentation mechanism is crucial for effectively removing the solid particles in recirculating aquaculture system (RAS) of Apostichopus japonicus, however, the underlying mechanism was still unclear. This study investigated the effects of diet with different sea mud addition on the fecal characteristics and microbiota. The experimental diet were the mixture of commercial feed and sea mud at the ratio of 1:1, 1:2, 1:3, 1:4 and 1:5, in which the added amount of sea mud was 50 %, 66.67 %, 75 %, 80 % and 83.33 %, respectively. The results showed that, at the end of aquaculture, Dx(50) in group 1:3 was the highest, while group 1:5 was the lowest. The fecal particle size distribution (PSD) appeared multi peak with the increase of sea mud addition. At the end of aquaculture, group 1:3 possessed the highest microbial diversity. BugBase phenotype prediction found that the microbial phenotypes in group 1:4 were mainly involved in functional expression, such as stress tolerance and potential pathogenicity. Significant correlation between environmental factors and fecal microbiota were found. Correlation analysis between fecal particle size and fecal microbiota showed that the abundance of pathogenic bacteria such as Vibrio, was higher on fecal particles with dispersed PSD. And NH4+-N removal rate decreased when Dx(10) decreased and Dx(90) increased. Thus, it was recommended that sea mud addition in diet should be <75 % in A. japonicus RAS.

Unravelling the origin of reaction-driven aggregation and fragmentation of atomically dispersed Pt catalyst on ceria support.

Metal-support interaction plays a crucial role in governing the stability and activity of atomically dispersed platinum catalysts on ceria support. The migration and aggregation of platinum atoms during the catalytic reaction leads to the redistribution of active sites. In this study, by utilizing a multimodal characterization scheme, we observed the aggregation of platinum atoms at high temperatures under reverse water gas shift reaction conditions and the subsequent fragmentation of platinum clusters, forming "single atoms" upon cooling. Theoretical simulations of both effects uncovered the roles of carbon monoxide binding on perimeter Pt sites in the clusters and hydrogen coverage in the aggregation and fragmentation mechanisms. This study highlights the complex effects of adsorbate and supports interactions with metal sites in Pt/ceria catalysts that govern their structural transformations under in situ conditions.

Understanding mono- and bi-metallic Au and Ni nanoparticle responses to fast heating.

Nanoparticle assembly, alloying and fragmentation are fundamental processes with significant implications in various fields such as catalysis, materials science, and nanotechnology. Understanding these processes under fast heating conditions is crucial for tailoring nanoparticle properties and optimizing their applications. For this, we employ molecular dynamics simulations to obtain atomic-level insights into nanoparticle behavior. The performed simulations reveal intricate details of sintering, alloying and fragmentation mechanisms shedding light on the underlying physical phenomena governing these processes. The calculation results help to visualize nanoparticle evolution upon undercritical and supercritical heating elucidating not only the role of temperature, but also of nanoparticle sizes and composition. In particular, it is shown that surface tension and surface energy play important roles not only in nanoparticle melting but also in its fragmentation. When the added energy exceeds a critical threshold, the nanoparticle begins to experience alternating compression and expansion. If the tensile stress surpasses the material's strength limit, fragmentation becomes prominent. For very small particles (with radius smaller than ∼10 nm), this occurs more rapidly, whereas sub-nano-cavitation precedes the final fragmentation in larger particles, which behave more like droplets. Interestingly, this effect depends on composition in the case of AuNi alloy nanoparticles, as expected from the phase diagrams and excess energy. The heating level required to overcome the mixing barrier is also determined and is shown to play an important role in the evolution of AuNi nanoparticles, in addition to their size. Furthermore, our findings provide insights into controlling nanoparticle synthesis for various applications in numerous nanotechnological domains, such as catalysis, sensors, material analysis, as well as deseas diagnostics and treatment. This study bridges the gap between experimental observations and theoretical predictions paving the way for designing advanced nanomaterials with enhanced functionalities.

Photodissociation of leucine-enkephalin protonated peptide: an experimental and theoretical perspective.

Understanding the competing processes that govern far ultraviolet photodissociation (FUV-PD) of biopolymers such as proteins is a challenge. Here, we report a combined experimental and theoretical investigation of FUV-PD of protonated leucine-enkephalin pentapeptide ([YGGFL + H]+) in the gas-phase. Time-dependent density functional theory (TD-DFT) calculations in combination with experiments and previous results for amino acids and shorter peptides help in rationalizing the evolution of the excited states. The results confirm that fragmentation of [YGGFL + H]+ results mainly from vibrationally excited species in the ground electronic state, populated after internal conversion. We also propose fragmentation mechanisms for specific photo-fragments such as tyrosine side chain loss (with an extra hydrogen) or hydrogen loss. In general, we observe the same mechanisms as for smaller peptides or protonated Tyr and Phe, that are not quenched by the presence of other amino acids. Nevertheless, we also found some differences, as for H loss, in part due to the fact that the charge is solvated by the peptide chain and not only by the COOH terminal group.

Measurement of charged and full jet production and nuclear modification factor in pp and p–Pb collisions with ALICE

The study of jet production in small collision systems is essential for testing our understanding of perturbative and non perturbative QCD and cold nuclear matter (CNM) effects. In addition, studies at high multiplicity in small collision systems exhibit signatures of collectivity, which is still not fully understood within a unified picture across system size. Jet quenching in small systems is not observed within current measurement precision, calling for more precise jet measurements. Results of charged particle and fully reconstructed jet production in pp and p-Pb collisions are presented at √SNN = 5.02 and 8 TeV, along with the corresponding nuclear modification factor RpPb at √SNN = 5.02 TeV. These results are the most precise measurements of the RpPb by ALICE to date. To investigate whether jet energy is redistributed in CNM, the crosssection ratios for different jet resolution parameters (R) are compared between pp and p–Pb collisions, as well as within each collision system. Finally, comparisons between data and model predictions are discussed. This result extends previous LHC measurements to lower jet transverse momentum, constraining hard parton production and fragmentation mechanisms applied in model calculations, and the impact of the nuclear-modified parton distribution function on jet production. This measurement also provides new constraints on jet quenching in small collision systems.

Numerical simulation of single bubble motion fragmentation mechanism in Venturi-type bubble generator

Numerical simulation of single bubble motion fragmentation mechanism in Venturi-type bubble generator

Experimental and Theoretical Investigations of the Fragmentation of Ethylenediamine Induced by Low-Energy (

Ethylenediamine is industrially used as an intermediate for the fabrication of many products. The development of new methodologies for synthesis compatible with the environment and sustainability, such as cold plasma processes, implicates reactions induced by nonthermal electrons. In this contribution, we study the interaction of low-energy (<10 eV) electrons with ethylenediamine. We show that electrons induce the fragmentation of the molecule into various anion fragments and associated neutral counterparts via dissociative electron attachment. The fragmentation mechanisms and energetics are discussed in the frame of DFT calculations. The fragmentation processes are quantified by the estimation of the cross sections and the branching ratios for competitive accessible dissociation routes.

A SiC membrane resistance recovery methodology based on dynamically dust cake layer analysis

Filter cake-induced resistance is a significant contributor to energy consumption in dust filtration processes. This can be optimized by adjusting inlet gas composition, membrane characteristics, and back-flushing parameters. In this study, calcium carbonate (CaCO3) dust with varying hygroscopicity was utilized to investigate the evolution mechanism of the filter cake on SiC membranes under different humidity conditions. The interacting force between particles and between the cake and membrane were analyzed to elucidate the fragmentation mechanism of the cake. It was observed that particles at higher relative humidity (increased RH from 40 % to 85 %) tend to form a more loosely packed cake (hydrophilic filter cake porosity and hydrophobic filter cake porosity increased from 70.8 % to 80.5 % and from 61.4 % to 69 %, respectively) with greater fragility (reduced cohesive force). This characteristic is advantageous for efficient backflushing operations. The strong adhesion between the filter cake and membrane hindered the recovery of the initial filtration resistance. For SiC membrane, the optimized back-flushing parameter is reservoir pressures of 0.2 and 0.15 MPa and pluse-jet intervals of 40 min to hydrophilic and hydrophobic dusts, respectively.

Molecular Ionization Dissociation Induced by Interatomic Coulombic Decay in an ArCH_{4}-Electron Collision System.

Interatomic Coulombic decay (ICD) is a significant fragmentation mechanism observed in weakly bound systems. It has been widely accepted that ICD-induced molecular fragmentation occurs through a two-step process, involving ICD as the first step and dissociative-electron attachment (DEA) as the second step. In this study, we conducted a fragmentation experiment of ArCH_{4} by electron impact, utilizing the coincident detection of one electron and two ions. In addition to the well-known decay pathway that induces pure ionization of CH_{4}, we observed a new channel where ICD triggers the ionization dissociation of CH_{4}, resulting in the cleavage of the C-H bond and the formation of the CH_{3}^{+} and H ion pair. The high efficiency of this channel, as indicated by the relative yield of the Ar^{+}/CH_{3}^{+} ion pair, agrees with the theoretical prediction [L. S. Cederbaum, J. Phys. Chem. Lett. 11, 8964 (2020).JPCLCD1948-718510.1021/acs.jpclett.0c02259; Y. C. Chiang et al., Phys. Rev. A 100, 052701 (2019).PLRAAN2469-992610.1103/PhysRevA.100.052701]. These results suggest that ICD can directly break covalent bonds with high efficiency, bypassing the need for DEA. This finding introduces a novel approach to enhance the fragmentation efficiency of molecules containing covalent bonds, such as DNA backbone.

A high-energy QCD portal to exotic matter: Heavy-light tetraquarks at the HL-LHC

By taking advantage of the natural stability of the high-energy resummation, recently discovered in the context of heavy-flavor studies, we investigate the inclusive hadroproduction of a neutral heavy-light, hidden-flavored tetraquark (Xcuc¯u¯ or Xbsb¯s¯ state), in association with a heavy (single c- or b-flavored) hadron or a light jet at the (HL-)LHC. We make use of the JETHAD multi-modular working package to provide predictions for rapidity, azimuthal-angle and transverse-momentum distributions calculated via the hybrid high-energy and collinear factorization, where the Balitsky–Fadin–Kuraev–Lipatov resummation of energy logarithms is supplemented by collinear parton densities and fragmentation functions. We rely upon the single-parton fragmentation mechanism, valid in the large transverse-momentum regime, to describe the tetraquark production. Our study represents a first attempt at bridging the gap between all-order calculations of high-energy QCD and the exotics.

Water release from dacitic melts near the glass transition and implications for volcanic eruptions

To get insights in the mechanisms of magma degassing and fragmentation, we performed dehydration experiments at ambient pressure with dacitic glasses containing between 1.42 and 5.28 wt% H2O. The focus was on the degassing behavior in the range of glass transition, i.e., from temperatures 50 K below to 50 K above the glass transition temperature Tg. At each T the duration of the experiments was varied between 5 and 125 h. Water contents and initial water speciation was determined by FTIR spectroscopy. Diffusion depth profiles were measured by Raman spectroscopy. We developed an equation to calculate the total water content along the depth profiles from the ratio of the fundamental OH stretching vibration band at 3550 cm−1 and the T-O-T bending band near 500 cm−1. Glasses with high water content (4.66–5.28 wt%) showed huge alterations, i.e., crack formation below Tg and crystallization at and above Tg, but glasses with water contents up to 2.5 wt% were visually unchanged and suitable for water diffusion analysis.The measured profiles of total water content vs. distance can be fitted well by an error function, assuming that the water content in the glass does not decrease to zero at the surface. However, the apparent water concentration at the surface and the total water diffusivity derived from the error function fitting decrease with increasing duration of the experiment. This clearly shows that degassing of dacitic melts is not a simple out-diffusion mechanism. The model of Coumans et al. (2020) that explicitly considers the kinetics of the interconversion of water species can reproduce the temporal evolution of the total water concentration profiles very well. Our results show the importance of considering explicitly the interconversion kinetics of water species when modelling water diffusion in melts at high viscosities. Due to the slow interconversion of OH groups to much more mobile water molecules, dehydration is much slower in the range of glass transition than predicted by diffusion models based on experiments performed on stable melts at magmatic temperatures.

High efficiency separation of fine coke powders by the novel jet-swirl scrubber: Characteristics and mechanisms

The deep removal of fine coke powders is an urgent need and remains a great challenge for the stable operation of the delayed coke system. Herein, a novel jet-swirl scrubber was developed. A combined approach utilizing CFD and DPM was employed to investigate the mechanism of droplet fragmentation. The results indicated that droplets underwent two stages of fragmentation in the convergent and throat sections under the influence of turbulent vortex structures. This leaded to a rapid reduction in droplet size and an effective dispersion. Thorough mixing with the gas phase occurred in the divergent section, facilitating enhanced capture of coke powders. Cold model experiments were conducted to examine the relationship between droplet size, coke powders capture efficiency, and gas-liquid separation efficiency. Under the condition of optimized critical droplet size 0.106 mm by adjusting the flow rate, the removal efficient of coke powders was up to 99.57 %. This work provides valuable technical support for further development and process optimization of the decoking powder unit in delayed coking system.

A coarse-to-fine pattern parser for mitigating the issue of drastic imbalance in pixel distribution

The significance of minute semantic components such as eyes and eyebrows tends to be overshadowed by larger components like skin and background, leading to inadequate graph attention from the model. Recent cropping-and-segmenting strategies comprise distinct stages and do not involve extensive interactions, thereby preventing joint optimization for collaborative perception. To mitigate this flaw, a coarse-to-fine pattern parsing network (CtFPPN) is proposed based on the capsule network (CapsNet). The CtFPPN incorporates a coarse-grained parser module, which generates binary coarse-scaled masks for larger components, and a fine-grained parser module, which performs fine-scaled parsing for smaller components using the coarse contexts as references. To establish a connection between two parsers, the discretization attention fragmentation mechanism (DAFM) is customized. The fine-grained parser has the option to aggregate projections from non-spatially-fixed collections of the coarse-grained parser, thereby embodying the principle of "coarse-to-fine" of CtFPPN. Under the premise of the existence of imbalanced pixel distribution, quantitative and ablation experiments of face and human parsing demonstrate the superiority of CtFPPN over the state-of-the-arts. Notably, CtFPPN excels in mitigating the pixel imbalance issues and accurately defining fine-scaled semantic boundaries of minuscule components.

Bubble fragmentation characteristics during the injection of subcooled water jet into hot liquid pool

Bubble fragmentation and size distribution in hot and cold fluid jet interaction are fundamental for industries such as energy and metallurgy, especially for safety analysis after steam generator tube rupture (SGTR) accidents in lead-cooled fast reactors. The opaqueness to light of the molten lead pool makes it difficult to capture the gas-liquid interface behavior and thus lacks relevant data. In this paper, silicone oil was used instead of lead to simulate the injection process of the SGTR accident. Then the jet visualization experiments were carried out to investigate the bubble fragmentation characteristics. The visualization results show that the jet between the hot and cold fluids process is accompanied by strong thermal interactions, eventually leading to many bubbles dispersed in the high-temperature liquid pool. Secondly, four mechanisms of action affecting bubble size were elaborated in this paper, among which local vapor explosion is the primary mechanism of bubble fragmentation. Finally, the data revealed that bubble size presented a lognormal distribution, and the fragmented bubble size distribution was modeled. This study is promising to provide guidance for the bubble behavior characteristics after SGTR accidents in lead-cooled fast reactors.

Microplastic fragmentation by rotifers in aquatic ecosystems contributes to global nanoplastic pollution.

The role of aquatic organisms in the biological fragmentation of microplastics and their contribution to global nanoplastic pollution are poorly understood. Here we present a biological fragmentation pathway that generates nanoplastics during the ingestion of microplastics by rotifers, a commonly found and globally distributed surface water zooplankton relevant for nutrient recycling. Both marine and freshwater rotifers could rapidly grind polystyrene, polyethylene and photo-aged microplastics, thus releasing smaller particulates during ingestion. Nanoindentation studies of the trophi of the rotifer chitinous mastax revealed a Young's modulus of 1.46 GPa, which was higher than the 0.79 GPa for polystyrene microparticles, suggesting a fragmentation mechanism through grinding the edges of microplastics. Marine and freshwater rotifers generated over 3.48 × 105 and 3.66 × 105 submicrometre particles per rotifer in a day, respectively, from photo-aged microplastics. Our data suggest the ubiquitous occurrence of microplastic fragmentation by different rotifer species in natural aquatic environments of both primary and secondary microplastics of various polymer compositions and provide previously unidentified insights into the fate of microplastics and the source of nanoplastics in global surface waters.

DFMCloudsim: an extension of cloudsim for modeling and simulation of data fragments migration over distributed data centers

Due to the increasing volume of data for applications running on geographically distributed Cloud systems, the need for efficient data management has emerged as a crucial performance factor. Alongside basic task scheduling, the management of input data on distributed Cloud systems has become a genuine challenge, particularly with data-intensive applications. Ideally, each dataset should be stored in the same data center as its consumer tasks so as to lead to local data accesses only. However, when a given task does not need all items within one of its input datasets, sending that dataset entirely might lead to a severe time overhead. To address this concern, a data fragmentation strategy can be considered in order to partition the datasets and process them in that form. Such a strategy should be flexible enough to support any user-defined partitioning, and suitable enough to minimize the overhead of transferring the data in their fragmented form. To simulate and estimate the basic statistics of both fragmentation and migration mechanisms prior to an implementation in a real Cloud, we chose Cloudsim, with the goal of enhancing it with the corresponding extensions. Cloudsim is a popular simulator for Cloud Computing investigations. Our proposed extension is named DFMCloudsim, its goal is to provide an efficient module for implementing fragmentation and data migration strategies. We validate our extension using various simulated scenarios. The results indicate that our extension effectively achieves its main objectives and can reduce data transfer overhead by 74.75% compared to our previous work.

High-throughput multitarget quantitative assay to profile the whole grain-specific phytochemicals alkylresorcinols, benzoxazinoids and avenanthramides in whole grain and grain-based foods.

Currently, there is a growing interest in using whole grain (WG)-specific phytochemicals to perform WG research, including research on dietary assessment, health mechanisms, and quality control. However, the current approaches used for WG-specific phytochemical analysis cannot simultaneously achieve coverage, specificity, and sensitivity. In the present study, a series of WG-specific phytochemicals (alkylresorcinols (ARs), benzoxazinoids (BXs) and avenanthramides (AVAs)) were identified, and their mass spectrometry (MS) fragmentation mechanism was studied by TOF MS. Based on diagnostic fragmentation ions and retention time prediction models, a LC-MS/MS method was developed. Through this method, 56 ARs, 13 BXs, and 19 AVAs in WGs and grain-based foods were quantified for the first time. This method was validated and yielded excellent specificity, high sensitivity and negligible matrix effects. Finally, we established WG-specific phytochemical fingerprints in a variety of WG and grain-based foods. This method can be used for WG quality control and WG precision nutrition research.

Influence of Si on the Structure and Martensitic Transformation in Deformed Ni–Mn–Ga Alloys

Abstract—The studying the effect of multiaxial isothermal forging on the microstructure and martensitic transformation in the Ni58Mn18Ga24 alloy is presented. Forging was carried out in two stages: stage 1 − forging at 700°C (4 passes, true degree of deformation e ≈ 1.64), stage 2 − forging at 500°C (1 pass, e ≈ 0.24). Forging led to the transformation of the original equiaxed grain structure. As a result of the 1st stage of processing, no new grains are formed. The new recrystallized grains are observed only after the 2nd stage of deformation, the proportion of which is very small. Apparently, the mechanism of fragmentation of the grain structure at the first stage is not triggered due to insufficient defect density at a deformation of 700°C. The characteristic temperatures of martensitic transformation are shifted to the low temperature region. The anharmonic change in the sample length is observed in the region of martensitic transformation for the both treated states. In general, this indicates a low level of defect density and internal stresses in the sample.