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AbstractData heterogeneity is a challenging issue for modern statistical data analysis. There are different types of data heterogeneity in practice. In this article, we consider potential structural changes and complicated tail distributions. There are various existing methods proposed to handle either structural changes or heteroscedasticity. However, it is difficult to handle them simultaneously. To overcome this limitation, we consider statistically and computationally efficient change point detection and localization in high-dimensional quantile regression models. Our proposed framework is general and flexible since the change points and the underlying regression coefficients are allowed to vary across different quantile levels. The model parameters, including the data dimension, the number of change points, and the signal jump size, can be scaled with the sample size. Under this framework, we construct a novel two-step estimation of the number and locations of the change points as well as the underlying regression coefficients. Without any moment constraints on the error term, we present theoretical results, including consistency of the change point number, oracle estimation of change point locations, and estimation for the underlying regression coefficients with the optimal convergence rate. Finally, we present simulation results and an application to the S&P 100 dataset to demonstrate the advantage of the proposed method. Supplementary materials for this article are available online, including a standardized description of the materials available for reproducing the work. [ABSTRACT FROM AUTHOR]

A vast amount of waste disposable face masks (FM) has threatened the ecosystem since COVID-19 became a pandemic. Given the urgency of the situation, this study innovatively assessed the potential utilization of the waste FM fibers to reinforce the subgrade in the permafrost regions. The effect of FM contents (0.5%, 1%, and 1.5%) and length–width (LW) ratios (1, 2, and 3) of the frozen silty clay specimens (−10°C) with different initial moisture contents (w = 15%, 20%, and 25%) on the mechanical behavior, including the peak deviatoric stress (q), the increment of peak deviatoric stress (λ), and the initial elastic modulus (E0), was analyzed. The pore structure change mechanism under the influence of FM and w was further revealed via nuclear magnetic resonance (NMR). The results indicated that the incorporation of FM improved the soil strength at a certain w, while the FM content and LW ratio were found to have different effects on the q values. The most effective reinforcement can be identified at w = 20%, according to the relatively large λ values (29.2%–79.1%). Moreover, the E0 values of specimens with higher initial moisture content and FM content were smaller, which can be explained by the cracks generated due to the water-ice phase change and uneven distribution of FM. NMR results revealed that the FM had less effect on the pore-water relaxation characteristics, and the change in soil structure was more remarkable in the frozen specimens with higher w. This study pointed out that the tension of FM and its bonding soil particles played the leading role in soil stress–strain behavior. Practical Applications: The results of this study recommend that waste face masks (FM) be added to the soil in the subgrade to improve its strength in permafrost regions. The mechanical properties (including the peak deviatoric stress and initial elastic modulus) of soils reinforced by various FM contents and different FM sizes were determined via experiments. The reinforcing mechanism is discussed by observing the surface of frozen soils and detecting the change in pore structure before and after freeze–thaw to explain the complex mechanical behavior of reinforced soils. The moisture content of soils is a significant factor influencing the reinforcement effect. According to the test results, different reinforcement parameters, for example, the content of additive FM and the FM size, should be selected in the specimens with different moisture contents for the best reinforcement effect. This paper provides novel and valuable guidance for waste FM utilization and subgrade strengthening in permafrost areas. [ABSTRACT FROM AUTHOR]

Pure WS2 film prepared by the radio frequency sputtering system exhibits a porous dendrite-like structure. The evolution in microstructure and tribological property of WS2 film were mainly investigated under different neutral gas irradiations using our self-made ground simulation device. After atomic nitrogen and atomic oxygen irradiation, the crystal structure and hardness of WS2 film were improved and wear life of film significantly prolong about 33% and 2 times, respectively. However, atomic hydrogen leads to a negative effect. The different results are found to be closely related to component change induced by irradiation on sliding contact area, further affecting formation of transfer film. Finally, lubricating mechanisms of WS2 film were revealed under different neutral gas irradiations in space environment. [ABSTRACT FROM AUTHOR]

Understanding the ecosystem history of reservoirs threatened by water-quality degradation is of utmost relevance for public health and ecosystem services. In this study, we examined the responses of diatom composition and diversity (richness and evenness) to long-term climate change and anthropogenic activities since 1960 CE in a deep subtropical reservoir (Qiandao Lake) in southeastern China. Besides, we detected structure changes in diatom community with F statistic test, and disclosed early warning signals of critical transition with a composite index comprising three resilience metrics, variance, skewness, and lag-1 autocorrelation (AR1). Our results showed that annual mean water level (MWL), annual mean temperature (Tann), ratio of total nitrogen to total phosphorus (N:P), and fish catch (FC) significantly affected diatom compositional change. Diatom richness was regulated primarily by MWL and Tann, whereas evenness was affected by MWL and FC. In general, human activities (most notably, water-level regulation) exerted the greatest influence on diatom composition and diversity changes since the impoundment. In maintaining the service function of Qiandao Lake, assessing the ecological effects of water-level regulation is important. F statistic test indicated striking structure changes of diatom assemblage in 1980 and 2002 CE. According to the composite resilience index, the early warning signals appeared a decade before the regime shift in 2002 CE. This study demonstrated that resource competition was probably the critical mechanism triggering regime shifts in the diatom community during the past 60 years. For management practice, our work suggested the necessity of monitoring water temperature and nutrient stoichiometry regularly, and implementing more stringent measures for constraining nutrient loads are necessary in preventing catastrophic shifts in Qiandao Lake ecosystem. [ABSTRACT FROM AUTHOR]

Leaf Trait Networks (LTNs) visually display the intricate trait connections in offering insights into how plants adapt to diverse environments. The pervasive environmental heterogeneity can influence plant diversity and functional traits. Various habitats sustain distinct species diversity and leaf trait differentiation, precisely as the degraded karst-heterogenous ecosystem caused by inhomogeneous microhabitats. However, how the LTNs respond to understory habitat heterogeneity and species diversity in degraded karst forests remains unclear. This study selected fifty-three forest plots for plant community survey and habitat investigation in a typical karst topography to visualize LTNs using twenty-one woody leaf traits. LTN architecture variations were analyzed in relation to habitat heterogeneity and species diversity through network-architectural parameters, including edge density, diameter, average path length, and average clustering coefficient, utilizing regression, principal component analysis, and structural equation model. The results showed a 35% variation in modularity across all plots, indicating distinct network architectural modularization differentiation. Network diameter and average path length displayed significant initial decreases followed by increases with ascending PC1 heterogeneity scores, indicating moderate heterogeneity sustained greater network connectivity. In addition, the network diameter, average path length, and average clustering coefficient significantly decreased with increasing species diversity, indicating that high species diversity enables greater connectivity and complexity. Moreover, the habitat heterogeneity significantly affected species diversity directly and affected the average clustering coefficient, diameter, average path length, and edge density indirectly through species diversity effects via SEM pathway analysis. Overall, habitat heterogeneity and woody plant diversity of karst forests significantly influence LTN architectures in degraded karst forests. In conclusion, moderate heterogeneity sustains greater network connectivity while species diversity jointly enhances connectivity and complexity by combining modular regulation of plant functional traits.

Physical and/or chemical changes such as refinement, component dissolution, exchange/adsorption, structural evolution and recombination of phyllosilicate minerals occur continuously in a naturally weakly acidic water environment. To compare the differential dissolution of cations that occupy various sites in vermiculite, trioctahedral vermiculite was dissolved in various concentrations of oxalate for 24 h and in 0.2 M oxalate for various durations. The concentration of ions in the leaching solution and the phase, structure and morphology of the original samples and acid-leached samples were analysed. Structural analysis showed that the 001 reflections of vermiculite gradually shifted to a higher angle and eventually disappeared after the dissolution of interlayer cations caused by acid leaching. The amount and rate of dissolution of each cation in the vermiculite showed that the octahedral cation Mg2+ is more soluble than Fe2+ and Fe3+. The dissolution rates of Al3+, Mg2+ and Ca2+ were greatest in the first 4 h and then decreased gradually. Amorphous silicon dioxide and calcium oxalate were formed during acid leaching, and calcium oxalate was formed in the first 4 h. After leaching with oxalate for various periods, the cation-exchange capacity (CEC) of the samples first increased and then decreased. Micromorphology analysis showed that the acid erosion process started from the edges. The results of this work contribute to our understanding of many natural geochemical processes, and they will be useful for several applications such as soil improvement, ecological restoration and environmental protection. [ABSTRACT FROM AUTHOR]

Hibiscus sabdariffa is a tropical plant with red calyxes whose anthocyanins, phenols, and antioxidant activity make it attractive to consumers both from a nutritional and medicinal standpoint. Its seasonality, perishability, and anthocyanin instability, led to the setup of stabilization methods comprising drying and powdering. However, its properties can often be altered during these stabilization processes. Treatments such as dehumidified-air-drying, infrared drying, and oven-drying, and their combination showed better quality preservation. Moreover, powder production enables superior biomolecule extractability which can be linked to a higher bioaccessibility. However, the required temperatures for powder production increase the bioactive molecules degradation leading to their antioxidant activity loss. To overcome this issue, ambient or cryogenic grinding could be an excellent method to improve the biomolecule bioavailability and accessibility if the processing steps are well mastered. To be sure to benefit from the final nutritional quality of the powder, such as the antioxidant activity of biomolecules, powders have to offer excellent reconstitutability which is linked to powder physicochemical properties and the reconstitution media. Typically, the finest powder granulometry and using an agitated low-temperature reconstitution media allow for improving anthocyanin extractability and stability. In this review, the relevant physicochemical and processing parameters influencing plant powder features from processing transformation to reconstitution will be presented with a focus on bioactive molecules and antioxidant activity preservation. [ABSTRACT FROM AUTHOR]

Many unit operations in the food industry are diffusional driven. These processes are usually very slow and difficult to handle for specific groups of raw materials. Vacuum impregnation (VI) is one example. Impregnating low-porous or densely-structured materials is problematic and often requires low pressure, which can negatively affect product quality and be expensive in energy consumption. This research aimed to evaluate ultrasound (US) as a factor in intensifying mass transfer and enhancing its effectiveness in the VI process. Experiments on impregnation enhanced with ultrasound applied at different stages of the process were carried out. Carrot, a difficult-to-process raw material, was impregnated with ascorbic acid as a mass transfer marker. The process’s effectiveness and selected quality parameters were then analyzed. Ultrasound was found to have a positive influence on mass transfer during VI. The effects of ultrasound enhancement were different for particular processes, and depended on the stage of the application and duration of US exposure. The greatest increase in the tissue’s ascorbic acid content (60% compared to the non-ultrasound-assisted process) was observed when ultrasound was applied continuously throughout the process. Applying ultrasound only during the relaxation (at atmospheric pressure) or aeration periods resulted in a similar effect – c.a. 20% increase in the marker’s content. The smallest increase (10%) was observed when ultrasound was applied only during the vacuum period. Applying US did not result in any unfavorable color change. In most cases, pH decreased, which is favorable for the semi-product’s stability. The carotenoid and phenolic compounds’ content did not decrease. The results unequivocally indicate that ultrasound has great potential for use as a mass transfer accelerator in the VI process for low porosity materials. The effectiveness of the US is influenced not only by pressure but also by exposure duration. The synergistic effect observed using ultrasound-enhanced impregnation throughout the process confirmed this hypothesis.

Metallic alloys are, by essence, ductile and stiff and can support loads without sudden rupture. This ductility becomes a disadvantage when applications require wear resistance. In this case, the hardening of the surface is required while retaining a core performance. Here, nitriding at low temperatures has proven to be beneficial and has potential. In fact, any phase transitions or unwanted compound precipitations that occur at higher temperatures have to be avoided as they would have a deleterious effect on the chemical homogeneity and mechanical properties. The present contribution summarizes the achievements made with such treatments on metallic alloys. We considered the most popular treatments, namely plasma, implantation, and gas nitridings. [ABSTRACT FROM AUTHOR]

Microwave (MW) drying method was adopted to enhance the liquid permeability of Scots pine lumber. Structure changes were characterized by stereoscope microscope, scanned electron microscope (SEM) and transmission electron microscope (TEM) examination. Pore parameters before and after MWtreatment were detected by mercury intrusion porosimetry (MIP) method, and the effect of structure changes on liquid permeability were analyzed. As stereoscope microscope, SEM and TEM examination results shown, macro and micro checks mainly developed at intercellcular of tracheids, intercellular of ray parenchyma and tracheid, while these checks extend main along the radial-longitudinal plane. Pit border destruction, aspirated pits' orus translocation and microchecks in tracheid cell wall were also observed. MIP test shown that pore volume and pore area increased as macro and micro checks generated to form new cavities. Microstructure changes would increase the quantity of pores or enlarge the pore diameter. Liquid flow pathways increased as macro and micro checks generated, aspirated pits reopened to form new pathways; liquid flow efficiency improved as porosity, pore volume and pore diameter increase which facilitate the liquid flow. [ABSTRACT FROM AUTHOR]

Surface treatments of Ti-6Al-4V alloys are of utmost importance for biomedical applications since they allow for tribological gain. Here, Ti-6Al-4V disks have been PBII nitrided at either 500, 600, 700 and 800 °C. A set of techniques (XRD, SEM-EDS, EBSD and GDOES) was used to characterize the surface microstructural and chemical changes. Nanoindentation was used to assess the induced changes in terms of mechanical properties. Two types of nitrided domains are revealed. Starting from the surface, a nitride bilayer composed of δ-TiN/ϵ-Ti2N with enhanced surface resistance is supported by an α-Ti(N) solid solution formed at depth. Hardness values peak at 12–14 GPa at the surface, which is almost twice as large as the bulk value (about 7 GPa). For the moderate temperatures used here, a deep (10–15 µm) and strong hardness (14 GPa) enhancement together with a smooth gradient can be achieved. [ABSTRACT FROM AUTHOR]

This study investigated the physicochemical structural changes in different types of rice (japonica rice [JR], indica rice [IR], and waxy rice [WR]) during oral digestion and explored the reasons for differences in oral digestion between the three different types. The results showed that, compared with JR (42.41 ± 3.06 mg/g) and WR (26.82 ± 0.67 mg/g), IR had the highest amylose content (49.95 ± 3.33 mg/g) and, related to this, hydrolysis rate. A correlation analysis showed that, the higher the amylose content, the harder the texture of rice, leading to longer chewing times and, as a result, a greater degree of hydrolysis. In addition, the higher the amylose content, the lower the exudate content and viscosity of rice, which affects chewing time and frequency, thereby affecting the degree of hydrolysis. Both X-ray computed tomography and scanning electron microscopy indicated that cooked IR had the loosest structure and the most pores, that were conducive to chewing and crushing and therefore contributed to the high hydrolysis rate. Analysis of the exudate structure showed that the amount of exudate affected rice pores. More exudates lead to pore coverage and a tight structure. [ABSTRACT FROM AUTHOR]

Polygonatum cyrtonema Hua (PC) with different processing degrees during the nine-steam-nine-bask processing was selected as the research object to investigate the changes of polysaccharide structure and their protective effect on cisplatin-induced acute kidney injury (AKI) in mice. The polysaccharides (PCP0, PCP4 and PCP9) were extracted, whose polysaccharide contents were 62.45 %, 60.34 % and 58.23 %, respectively. After processing, the apparent structure of PCPs became looser, and the apparent viscosity and the particle size were decreased. The PCPs were acidic polysaccharides containing pyran rings, and furan rings were present in PCP4 and PCP9. Besides, processing destroyed the original β-glucoside bond in PCP0. PCPs were all composed of Rha, Man, Glu, Gal, Xyl and Ara with different ratio. In addition, AKI mice model was successfully constructed by single intraperitoneal injection of 15 mg/kg cisplatin. PC extracts (3.0750 g/kg) and PCP (0.1599 g/kg) significantly decreased the kidney function, liver function, and percentage of renal cell apoptosis, and improved the kidney structure of AKI mice (p < 0.05). PC and PCP have protective effect on cisplatin-induced AKI mice, and the protective effect was improved with the increase of processing degree. Under the same processing degree, the protective effect of PC mixed extract was better than that of PCP. [ABSTRACT FROM AUTHOR]

The reduced graphene oxide paper (rGOP) has been irradiated with different energy and dose, namely 200 keV and 1000 keV electron with dose ranging from 2 × 1014 e/cm−2 × 1016 e/cm−2, using a ground-based irradiation simulator. The electrical properties, surface morphology, structural defects, interlayer spacing, thermal stability of rGOP before and after irradiation were systematically investigated. Results indicate that the electrical resistance and the I D /I G ratio increases pose irradiation, indicative of defect presence. The ratio of total carbon to total oxygen atoms (C/O) is 4.7 in pristine materials, with no obvious alteration in materials irradiated with 200 keV electron, while increased to 6.8 subjected to 1000 keV electrons. The 1000 keV electron irradiated material exhibits improved morphology from the SEM image. The above results were further verified by the change in the spacing of graphene layers in the material. FLUKA simulation results demonstrated that the 1000 keV electron can pass through penetrate the rGOP, while the 200 keV electron is in the near surface for irradiated materials. Changes in resistance of rGOP are attributed to defects, structural disorder, oxygen-containing functional groups, and variations in the total C/O atom ratio. The results show that the structure and properties of rGOP can be influenced by irradiation energy and dose of electron. • The different energy and dose electron irradiation effect on reduced graphene oxide paper was studied. • The defects, disorder structure and total C/O ratio of materials were changed. • The surface electrical property, surface morphology and thermal stability and of materials was influenced. [ABSTRACT FROM AUTHOR]

Natural gas hydrates are abundant in marine sediments and have great potential for resource development. However, there is still a lack of clarity regarding the impact of hydrate phase transition on the structure change of marine sediments. Hence, we conducted in-situ microscale experiments of hydrate phase transition in clayey sediments obtained from the active Haima cold seep area in South China Sea. By utilizing advanced X-ray Computed Tomography technology and a controlled method of hydrate phase transition, we successfully observed the dynamic behaviors of hydrate formation and decomposition, and revealed their effects on sediment structure and solid migration. Our findings suggested that methane hydrates initially occupy primary pores while generating new pores and fractures in clayey sediments. These processes lead to changes in pore morphology and anisotropy, characterized by a decrease in the degree of anisotropy and an increase in fractural and shape factor of pores. During hydrate decomposition, methane hydrates tend to be reformed in clayey sediments before initiating the decomposition process. More significantly, the combining effects of hydrates reformation and decomposition lead to occurrence of enlarged pores in sediments, resulting in unpredictable structural failure of the sediment. Furthermore, the simulation results of solid migration in sediments revealed that the solid particles migrate towards the bottom of the sediments during hydrate formation, leading to the compaction of sediment structure. Conversely, during hydrate decomposition, the solid particles move significantly towards the upper region of the sediment due to fluid seepage through newly generated and enlarged pores. The structure change and solid migration mechanisms revealed in this study highlight the potential risks during hydrate phase transition such as sediment instability and sand production, offering valuable insights into efficient and secure hydrate exploitation. [Display omitted] • Methane hydrates are in-situ formed and decomposed in marine clayey sediments; • Hydrate formation induces the new generation of pores and fractures; • Hydrate decomposition induces enlarged pores and irreversible effects on mechanics; • Different pathways with directions of the solid migration are represented; • Structure change may lead to sediment instability and environmental issues in cold seeps. [ABSTRACT FROM AUTHOR]

Hibiscus sabdariffa is a tropical plant with red calyxes whose anthocyanins, phenols, and antioxidant activity make it attractive to consumers both from a nutritional and medicinal standpoint. Its seasonality, perishability, and anthocyanin instability, led to the setup of stabilization methods comprising drying and powdering. However, its properties can often be altered during these stabilization processes. Treatments such as dehumidified-air-drying, infrared drying, and oven-drying, and their combination showed better quality preservation. Moreover, powder production enables superior biomolecule extractability which can be linked to a higher bioaccessibility. However, the required temperatures for powder production increase the bioactive molecules degradation leading to their antioxidant activity loss. To overcome this issue, ambient or cryogenic grinding could be an excellent method to improve the biomolecule bioavailability and accessibility if the processing steps are well mastered. To be sure to benefit from the final nutritional quality of the powder, such as the antioxidant activity of biomolecules, powders have to offer excellent reconstitutability which is linked to powder physicochemical properties and the reconstitution media. Typically, the finest powder granulometry and using an agitated low-temperature reconstitution media allow for improving anthocyanin extractability and stability. In this review, the relevant physicochemical and processing parameters influencing plant powder features from processing transformation to reconstitution will be presented with a focus on bioactive molecules and antioxidant activity preservation.

Metallic alloys are, by essence, ductile and stiff and can support loads without sudden rupture. This ductility becomes a disadvantage when applications require wear resistance. In this case, the hardening of the surface is required while retaining a core performance. Here, nitriding at low temperatures has proven to be beneficial and has potential. In fact, any phase transitions or unwanted compound precipitations that occur at higher temperatures have to be avoided as they would have a deleterious effect on the chemical homogeneity and mechanical properties. The present contribution summarizes the achievements made with such treatments on metallic alloys. We considered the most popular treatments, namely plasma, implantation, and gas nitridings.

Polysaccharides are the important bioactive macromolecules in Agrocybe cylindracea , but their changes are as yet elusive during developmental process. This study investigated the dynamic changes of polysaccharides from A. cylindracea fruiting body water extract at four developmental stages and its structure characteristics. Results revealed that the polysaccharides from A. cylindracea water extract significantly increased at the pileus expansion stage and the increased fraction could be α-glucan. The further purification and identification indicated that this α-glucan was a glycogen. It had typical morphology of β particles with a molecular weight of 1375 kDa. Its backbone comprised α-D-(1 → 4)-Glc p and α-D-(1 → 4,6)-Glc p residues at a ratio of 5:1, terminated by α-D-Glc p residue. Rheological behavior suggested that it was a Newtonian fluid at the concentration of 1 %. In addition, despite both the glycogen and natural starch were composed of D-glucose, they exhibited the entirely distinct Maltese cross characteristic and unique crystalline structure. This study is the first to demonstrate the presence of abundant glycogen in the pileus expansion stage of A. cylindracea , which provides new insights on the change patterns of fungal polysaccharides. [Display omitted] • Agrocybe cylindracea polysaccharides (SACP) at different stages were investigated. • The α-glucan of SACP significantly increased at the pileus expansion stage. • This α-glucan was identified as a glycogen with typical morphology of β particles. • The backbone of glycogen comprised α-(1 → 4)-Glc p and α-(1 → 4,6)-Glc p residues at 5:1. • Glycogen and starch had the distinct characteristic and crystalline structure. [ABSTRACT FROM AUTHOR]

The problem of control of a multidimensional object with one control action and with a channel selector is considered. It is shown that an effective means of constructing such logical-dynamic systems is the use of adaptation algorithms. The methods of coordination and adaptation of channels for controlling the fuel consumption of gas turbine engines are analyzed. The simulation results are presented. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coaly graphite is an important natural graphite resource that derived from coal under a natural process that associated with igneous intrusion. Flake graphite is usually used for the chemical synthesis of graphene oxide (GO), the main precursor for preparation of graphene, but few papers pay attention to preparing GO using coaly graphite. In this paper, four kinds of natural coaly graphite with different graphitization degrees were exposed to a modified Hummer’s oxidation method to prepare GO. The flake graphite sample was also used for comparison. The results showed that the structural change process from graphite to GO were significantly affected by the graphitization degree of the original coaly graphite. The relationship between yields of GO and graphitization degrees of the coaly graphite was explored. The mechanism of why the graphite with low graphitization degrees cannot be totally oxidized was proposed. Coaly graphite with a graphitization degree of higher than 80% was easier to be oxidized and yielded the same amount of GO as the flake graphite did, suggesting it is the potential substitute for the flake graphite to produce GO in bulk quantities.

Surface treatments of Ti-6Al-4V alloys are of utmost importance for biomedical applications since they allow for tribological gain. Here, Ti-6Al-4V disks have been PBII nitrided at either 500, 600, 700 and 800 °C. A set of techniques (XRD, SEM-EDS, EBSD and GDOES) was used to characterize the surface microstructural and chemical changes. Nanoindentation was used to assess the induced changes in terms of mechanical properties. Two types of nitrided domains are revealed. Starting from the surface, a nitride bilayer composed of δ-TiN/ϵ-Ti2N with enhanced surface resistance is supported by an α-Ti(N) solid solution formed at depth. Hardness values peak at 12–14 GPa at the surface, which is almost twice as large as the bulk value (about 7 GPa). For the moderate temperatures used here, a deep (10–15 µm) and strong hardness (14 GPa) enhancement together with a smooth gradient can be achieved.

This article identifies parallels between Leslie Marmon Silko's Storyteller and Almanac of the Dead, focusing on the recurrence of Yellow Woman, a figure of Keresan orature. Yellow Woman embodies female sensuality and its potential to incite social or structural change within communities, and I argue that in Almanac, Silko employs textual reinterpretations of Yellow Woman to demonstrate the importance of cross-cultural, indigenous-led movements toward decolonization. Finally, I compare Almanac to the current Idle No More movement, noting their similarities as vast transnational, transindigenous, and even transracial campaigns that model beneficial Native and non-Native ally relationships within the struggle against colonial oppression.

[Display omitted] • Leaf trait networks visualize multidimensional trait interconnections. • Habitat heterogeneity and plant diversity jointly influence trait networks. • Moderate habitat heterogeneity sustains greater trait network connectivity. • High plant diversity increased network connectivity and complexity. Leaf Trait Networks (LTNs) visually display the intricate trait connections in offering insights into how plants adapt to diverse environments. The pervasive environmental heterogeneity can influence plant diversity and functional traits. Various habitats sustain distinct species diversity and leaf trait differentiation, precisely as the degraded karst-heterogenous ecosystem caused by inhomogeneous microhabitats. However, how the LTNs respond to understory habitat heterogeneity and species diversity in degraded karst forests remains unclear. This study selected fifty-three forest plots for plant community survey and habitat investigation in a typical karst topography to visualize LTNs using twenty-one woody leaf traits. LTN architecture variations were analyzed in relation to habitat heterogeneity and species diversity through network-architectural parameters, including edge density, diameter, average path length, and average clustering coefficient, utilizing regression, principal component analysis, and structural equation model. The results showed a 35% variation in modularity across all plots, indicating distinct network architectural modularization differentiation. Network diameter and average path length displayed significant initial decreases followed by increases with ascending PC1 heterogeneity scores, indicating moderate heterogeneity sustained greater network connectivity. In addition, the network diameter, average path length, and average clustering coefficient significantly decreased with increasing species diversity, indicating that high species diversity enables greater connectivity and complexity. Moreover, the habitat heterogeneity significantly affected species diversity directly and affected the average clustering coefficient, diameter, average path length, and edge density indirectly through species diversity effects via SEM pathway analysis. Overall, habitat heterogeneity and woody plant diversity of karst forests significantly influence LTN architectures in degraded karst forests. In conclusion, moderate heterogeneity sustains greater network connectivity while species diversity jointly enhances connectivity and complexity by combining modular regulation of plant functional traits. [ABSTRACT FROM AUTHOR]

The color stability of anthocyanins (ACN) has been shown to be improved by interaction with whey proteins (WP). In this study, we explore the ACN–WP interaction using Fourier transform infrared spectroscopy (IR). ACN from purple corn, grape, and black carrot (50 μM) were evaluated. IR spectra (4000–700 cm−1) were collected for native and preheated (40–80 °C) WP (5 mg/mL) and ACN–WP mixtures at pH 7.4. Soft independent modeling of class analogy was used to analyze the IR data. The WP secondary structure changed after heat treatments and after interaction with ACN. As expected, the WP α-helices decreased, and β-sheet increased after heat treatment. The intensities of the WP amide I and II bands decreased after ACN addition, revealing a decrease in the WP α-helix content. Higher preheating temperatures (70–80 °C) resulted in a more disordered WP structure that favored stronger WP–ACN interactions related to amide III changes. Addition of ACN stabilized WP structure due to heat denaturation, but different ACN structures had different binding affinities with WP. WP structure had less change after interaction with ACN with simpler structures. These results increase our understanding of ACN–WP interactions, providing a potential strategy to extend anthocyanin color stability by WP addition.

• Organic molecules interact with the copper(II) centre and cause structural transformations of Cu-MOF. • Solvents with suitable dipole moments (1.7–3.9) can promote structural changes and avoid the damage of the structure. • Solvent with the high dipole moments such as DMSO can break Cu-N and Cu-O bonds of MOF. • The structural change can release active sites of Cu-MOF catalysts in the reaction and promote the activity. Metal-organic frameworks (MOFs) are an emerging class of catalysts that posess large surface area due to intrinsic porosity, and high metal loading. However, they often lack catalytic properties due to the saturated coordination sphere of metal centres. Some MOFs have been found to exhibit good to excellent catalytic activity in a limited number of reactions, resulting from solvent induced changes of the coordination sphere. In this work the coordination sphere changes of Cu(bpy)(H 2 O) 2 (BF 4) 2 (bpy) (bpy = 4,4-bipyridine) affected by common solvents with different dipole moments were studied by means of solution-state 1H and 19F NMR. It was found that organic molecules interact with the copper(II) centre and cause structural transformations of Cu-MOF in proportion to both the dipole moment and concentration of solvent. The sensitive NMR resonances reveal an exchange of the BF 4 ¯ anions to DMSO (dimethylsulfoxide) molecules at axial positions of Cu(II) and even breakage of Cu-N and Cu-O bonds in equatorial positions with increasing DMSO concentration. Therefore, solvents with suitable dipole moments (1.7–3.9) can promote structural changes and, thus release highly active sites in the reaction, which can efficiently enhance the activity of Cu-MOF catalysts. [ABSTRACT FROM AUTHOR]

Copyright of Al Zakra / Dakira is the property of University of Kasdi Merbah Ouargla and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Acid-base stress enhanced exopolysaccharides yield produced by Lysinibacillus sphaericus Ya6. • Alkaline stress reduced the average molecular weight of exopolysaccharides and improved Superoxide anion radical scavenging capacity. • Acid stress increased mannose content in exopolysaccharides. • DPPH radical scavenging capacity improved significantly under alkaline stress. In this study, the structure and antioxidant activity of exopolysaccharides (EPS) produced by Lysinibacillus sphaericus Ya6 under different acid-base stresses were investigated. The structure of EPS was analyzed by UV-visible and mid-IR, and the monosaccharide composition and the molecular weight were determined by High-performance liquid chromatography (HPLC) and high-performance gel permeation chromatography respectively. The findings indicated that EPS produced by Lysinibacillus sphaericus Ya6 was a homogenous polysaccharide with a molecular weight of 79.25 kDa that was composed of mannose and glucose. The molecular weight and monosaccharide composition of polysaccharides changed under acid-base stress conditions. With the addition of the acid-base stress level, the logarithmic growth period of Lysinibacillus sphaericus Ya6 was prolonged for a short while, but later growth rates and EPS production under stress conditions were all higher than under the control. In vitro determinations found that acid-base stress boosted the antioxidant activity of EPS. Particularly under conditions of alkaline stress, DPPH radical scavenging capacity and superoxide anion scavenging of EPS were higher than those of the control, and their capacities to scavenge DPPH was increased from 39.30% (the control) to 95.65% at pH 10.0, which was close to ascorbic acid's (95.77%) as a positive control. [Display omitted] [ABSTRACT FROM AUTHOR]

Understanding of the defect evolution mechanism under irradiation is very important for the research of pressure vessel steel embrittlement. In this paper, the embedded atom method (EAM) based canonical ensemble molecular dynamics (MD) method was used to study the evolution of the stacking structure of different nano-sized Cun (n = 13, 43 and 87) clusters in an Febulk embedded with BCC lattice structure during continuous heating. The mean square displacement, pair distribution functions and atomic structures of Cu atom clusters at the nanometer scale were calculated at different temperatures. The structural changes present apparent differences, for the Febulks contain nano-sized Cu clusters with different atom numbers during heating. For the Febulk–Cu13 system, since the ability to accommodate the atomic Cu in the Fe substrate is lesser, a small number of Cu atoms in BCC lattice positions cannot influence the whole structure of the Fe-Cu system. For the Febulk–Cu43 system, with an increase in temperature, a Cu atomic pile structural change happened, and the strain areas decreased significantly in the Febulk, but a single strain area grew large. For the Febulk–Cu87 system, when the Cu atoms are constrained by the Fe atoms in bulk, only a few of the Cu atoms adjust their positions. With the increase in temperature, strain in the Fe eased.

In this paper, a method for detecting synergistic effects of the interaction of elements in multi-element stochastic systems of separate redundancy, multi-server queuing, and statistical estimates of nonlinear recurrent relations parameters has been developed. The detected effects are quite strong and manifest themselves even with rough estimates. This allows studying them with mathematical methods of relatively low complexity and thereby expand the set of possible applications. These methods are based on special techniques of the structural analysis of multi-element stochastic models in combination with majorant asymptotic estimates of their performance indicators. They allow moving to more accurate and rather economical numerical calculations, as they indicate in which direction it is most convenient to perform these calculations.

The voltage fade of Li-rich layered oxide cathode material Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 (LNCM) heavily hinders its application in Li-ion batteries. Herein, we revisit the origin of the voltage fade of LNCM and propose a solution to suppress this effect. It is demonstrated that the voltage fade of the LNCM cathode comes from the structural change of the crystal from layer structure to spinel structure, involving all the cations rearrangement. Such rearrangement of all the cations in LNCM is due to the high degree of delithiation and oxygen release at high cutoff voltage of 4.8 V. It is also evidenced that nickel and cobalt change from low valence to high valence at the discharged state, which not only inhibits the transport of lithium ions, but also leads to the loss of high voltage platforms. In particular, the cation rearrangement of Li/Mn causes valence change from Mn4+ to Mn3+, resulting in the decrease of discharge voltage platform at the cutoff voltage of 4.8 V much higher than at 4.6 V. The lower charge cutoff voltage can be a solution to suppress the voltage fade of LNCM cathode materials and have a good stability of LNCM cathode materials without compromising the battery performance. Image 1 • The voltage fade of Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 comes from the layer to spinel structure. • All the cations rearrangement involves in the structure change. • Nickel and cobalt change from low valence to high valence at the discharged state. • The Mn4+ to Mn3+ in Mn rearrangement decreases the discharge voltage platform. • The lower charge cutoff voltage is a solution to suppress the voltage fade of Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 without compromising the battery performance. [ABSTRACT FROM AUTHOR]

Zirconolite based glass-ceramic has been deemed as a promising waste form for high-level waste (HLW). In this study, the zirconolite (nominally CaZrTi 2 O 7) glass-ceramic based on a SiO 2 -B 2 O 3 -Na 2 O-CaO-ZrO 2 -TiO 2 -Al 2 O 3 system was sought to be synthesized by two-step thermal treatment. The temperature effects such as nucleation temperature and cooling rate were studied. The influence of the Ce-dopant concentration on crystallization behavior was also investigated. For characterization, powder X-ray diffraction (XRD), thermogravimetry-differential scanning calorimeter (TG-DSC) and scanning electron microscopy (SEM) were applied. Our results illustrate that homogeneous zirconolite with the particle size of 1.8 μm can be the target phase when the glass matrix underwent a rapid cooling process and the nucleation temperature was controlled at around 860 °C. Besides, the results also indicate that the distribution of the zirconolite along with its lattice parameters change regularly as the increase of CeO 2 concentration. A larger crystal size of zirconolite phase and some trace amounts of precipitated phases are observed when the CeO 2 concentration exceed 3 wt%. This work emphasizes the synthesis of zirconolite glass-ceramic in a SiO 2 -B 2 O 3 -Na 2 O-CaO-ZrO 2 -TiO 2 -Al 2 O 3 system, which is expected to provide basic technical data for underground disposal of HLW. [ABSTRACT FROM AUTHOR]

[Display omitted] • The application of ultrasound positively influenced the mass transfer. • The negative impact of ultrasound on quality parameters was not indicated. • Ultrasonic assisted vacuum impregnation is pressure dependent. Many unit operations in the food industry are diffusional driven. These processes are usually very slow and difficult to handle for specific groups of raw materials. Vacuum impregnation (VI) is one example. Impregnating low-porous or densely-structured materials is problematic and often requires low pressure, which can negatively affect product quality and be expensive in energy consumption. This research aimed to evaluate ultrasound (US) as a factor in intensifying mass transfer and enhancing its effectiveness in the VI process. Experiments on impregnation enhanced with ultrasound applied at different stages of the process were carried out. Carrot, a difficult-to-process raw material, was impregnated with ascorbic acid as a mass transfer marker. The process's effectiveness and selected quality parameters were then analyzed. Ultrasound was found to have a positive influence on mass transfer during VI. The effects of ultrasound enhancement were different for particular processes, and depended on the stage of the application and duration of US exposure. The greatest increase in the tissue's ascorbic acid content (60% compared to the non-ultrasound-assisted process) was observed when ultrasound was applied continuously throughout the process. Applying ultrasound only during the relaxation (at atmospheric pressure) or aeration periods resulted in a similar effect – c.a. 20% increase in the marker's content. The smallest increase (10%) was observed when ultrasound was applied only during the vacuum period. Applying US did not result in any unfavorable color change. In most cases, pH decreased, which is favorable for the semi-product's stability. The carotenoid and phenolic compounds' content did not decrease. The results unequivocally indicate that ultrasound has great potential for use as a mass transfer accelerator in the VI process for low porosity materials. The effectiveness of the US is influenced not only by pressure but also by exposure duration. The synergistic effect observed using ultrasound-enhanced impregnation throughout the process confirmed this hypothesis. [ABSTRACT FROM AUTHOR]

In order to obtain and study time-frequency characteristics of fabric tensile failure modes, four kinds of fabrics is woven with changing different fabric organizational structures and weft densities, dynamic audio signals for different fabrics in tensile failure process is collected with the aid of self-built acoustic emission detection system on the conventional fabric tensile tester, and the collected signal is analyzed and processed by using Matlab software to run a program compiled based on Hilbert Huang transform. The results show that AE signal curve is completely corresponding to tensile load-displacement curve in fabric tensile process, and characterizations of three failure modes about structure change, yarn deformation, and yarn fracture can be clearly distinguished. The characteristic frequency of four kinds of fabrics in structure change stage is the same as 100 Hz, which can be derived from the same source (orthogonal friction of yarns), and has nothing to do with the fabric organizational structure or density. The structure change stage has something to do with yarn strength utilization in such aspects as the AE signals characteristics of duration, amplitude, energy, and so on.

Aspen wood was subjected to autohydrolysis as a pre-treatment to characterize the structural changes occurring in lignin fractions during the pre-treatment process. Milled wood lignin (MWL) was isolated from both the native aspen wood and hydrolyzed wood chips, and its structural features were characterized by Fourier transform infrared (FT-IR), quantitative 13C, two-dimensional heteronuclear single quantum coherence (2D HSQC), and 31P nuclear magnetic resonance (NMR) spectroscopies, gel permeation chromatography/multi-angle laser light scattering (GPC-MALLS), and thermal analysis. The lignin remaining in the hydrolyzed wood chips revealed more phenolic OH groups, fewer aliphatic OH groups, higher syringyl/guaiacyl ratios (S/G), higher molecular weights, and narrower polydispersities than the native lignin of aspen wood. The inter-unit linkages of β-O-4 were noticeable cleaved, but the condensed structures in the lignin formed when undergoing autohydrolysis of high severity, resulting in elevated amounts of C-C linkages. Moreover, it was found that autohydrolysis promoted the removal of -OCH3 groups and increased the thermal stability of lignin fractions.

In the present study, the toxic influence of two metallic ions on serum albumin was studied by using fluorescence, UV/vis, circular dichroism spectroscopy, and molecular docking, with the aim of delineating the effects of Pt(II) and Au(III) ions on the secondary and tertiary structure, the transportation function, the thermal stability, and the esterase-like activity of bovine serum albumin (BSA). The conformational change occurring in protein structure was monitored by CD and fluorescence spectroscopy. Pt(II) and Au(III) could react with some functional groups of BSA, making the secondary structure change and increasing the microenvironment around Tyr residues of BSA. The content of α-helix decreased remarkably and the contents of β-sheet, and random coil increased with increasing concentration of Pt(II) or Au(III) ion. Compared with Pt(II) ion, Au(III) ion is more likely to damage the tertiary structure of BSA and a higher number of Tyr residues are affected in Au(III)-BSA system. The fluorescence and UV/vis spectral results indicated the formation of Pt(II)-BSA and Au(III)-BSA complexes. In addition, metal ion binding decreased the ANS binding ability, the reversibility of the thermal unfolding process and the esterase-like activity of BSA. Therefore, this paper is expected to improve the toxicity evaluation mechanism of platinum and gold ions. [ABSTRACT FROM AUTHOR]

Mudstone chemical compaction plays a very important role in the pore evolution, microstructure and formation of abnormal pressure, but there has been weak research on it so far. Recent research progresses about mudstone chemical compaction were systematically summarized, including action mechanism, mudstone texture changes, well logging interpretation and identification; finally, the key issues in mudstone chemical compaction were discussed. The results show that the chemical compaction mainly refers to smectite-illite transition, which is controlled by chemical kinetics and affected by temperature, time and mineral composition; it may be not obvious that the bulk volume expansion is caused by the conversion of interlayer water into intergranular water in clay mineral, and the chemical compaction may cause skeletal weakening and the effective stress transfer; the siliceous cementation and aligned clay mineral fabric significantly reduce the permeability of mudstone, and may obviously alter the mudstone compaction coefficient during clay diagenesis process; the smectite-illite transition causes the change of the relationship between effective stress and porosity of mudstone, and the logging response shows decreasing acoustic value and increasing density value; in addition, the mudstone chemical compaction shows higher speed ratio of longitudinal and transverse waves(Vp/Vs), and lower wave impedance and shear modulus. Some key problems in mudstone chemical compaction still need to be further studied, including the chemical compaction and the structure of clay mineral, the effect of organic matter on mudstone chemical compaction, the chemical compaction and characteristics of mudstone rheology, the difference between chemical undercompaction and compaction disequilibrium, and the prediction method of mudstone overpressure in the process of chemical diagenesis. [ABSTRACT FROM AUTHOR]

To achieve sustainable production and consumption patterns in the modern world, emerging countries are concentrating more on how economic variables may employ carbon neutrality targets appropriately. Using renewable energy, structural changes initiative, and imposing environmental taxes are all part of the plan to achieve the carbon neutrality goal in terms of reduced carbon emissions (CO 2), haze pollutants, and greenhouse gases (GHG). Environmental taxation, renewable energy, structural changes, trade openness, and foreign direct investment (FDI) are aspects taken into account in this study, along with the long-term viability of the natural ecology in the E7 (China, Turkey, India, Russia, Brazil, Indonesia, and Mexico) economies. The Driscoll Kraay fixed effect OLS technique and the Method-of-Moment quantile (MMQ) regression technique were adopted for the baseline analysis for the data span of 2000 to 2020. From the empirical analysis, it was discovered that environmental Tax, structure change, and renewable energy have a negative connection with carbon emissions for the understudy countries. Moreover, the pollutant haven hypothesis (PHH) was confirmed since the findings discovered a positively significant relation involving FDI and carbon emission. Similarly, trade openness was seen to have a positive connection with carbon emissions. Thus, it is concluded that effective environmental taxation, renewable energy enhancement, and structure changes mitigate pollution while trade openness and FDI inflow enhance carbon emission for the E7 economies. According to the results, rigorous environmental tax rules will enable enterprises to transition manufacturing to green and sustainable alternatives. Finally, the report recommends that transferring tax money to research and development of sustainable technology programmes will enable governments to meet the SDG-7 and SDG-13 objectives of the United Nations. • Examine the effect of environmental Tax, renewable energy, and structural change on CO 2 emission for E7 economies. • Driscoll-Kraay and moment-of-moment quantile techniques are used in this study. • Environmental tax, renewable energy and structure change improve the E7 economies' environment. • The PHH as well as the trade-openness-CO 2 nexus, are confirmed by the findings. • Clean energy infrastructure and effective environmental Tax, as well as structural changes implementation, are essential for carbon neutralization for the E7 economies. [ABSTRACT FROM AUTHOR]

Fourier Transform Infrared Spectroscopy (FTIR) is adopted to study the aging characteristics of poly(acrylonitrile–butadiene–styrene)/polycarbonate (ABS/PC) blend under UV-irradiation in air by analyzing the variation of the three main absorbance at about 967 cm − 1 , 1720 cm − 1 and 3420 cm − 1 associated with carbon-hydrogen bonds belonging to 1,4 butadiene, carbonyl and hydroxyl groups, respectively. Results indicate that, under UV-irradiation in air, the photo-oxidation of the blend is not a simple combination of the photo-oxidation of corresponding ABS and PC themselves and takes place predominantly at the ABS component. Due to the interaction between the two components and the Fries rearrangement taken place in the PC component during the UV-irradiation in air, the ABS/PC blends behave higher photo-stability than ABS has. [ABSTRACT FROM AUTHOR]

Forecasting the rapid intensification of tropical cyclones over offshore areas remains difficult. In this article, the Weather Research and Forecast (WRF) model was used to study the rapid intensification of Typhoon Haikui (1211) off the shore of China. After successful simulation of the intensity change and track of the typhoon, the model output was further analyzed to determine the mechanism of the rapid change in intensity. The results indicated that a remarkable increase in low-level moisture transportation toward the inner core, favorable large-scale background field with low-level convergence, and high-level divergence played key roles in the rapid intensification of Typhoon Haikui in which high-level divergence could be used as an indicator for the rapid intensity change of Typhoon Haikui approximately 6 h in advance. An analysis of the typhoon structure revealed that Typhoon Haikui was structurally symmetric during the rapid intensification and the range of the eyewall was small in the low level but extended outward in the high level. In addition, the vertically ascending motion, the radial and tangential along wind speeds increased with increasing typhoon intensity, especially during the process of rapid intensification. Furthermore, the intensity of the warm core of the typhoon increased during the intensification process with the warm core extending outward and toward the lower layer. All of the above structural changes contributed to the maintenance and development of typhoon intensity. [ABSTRACT FROM AUTHOR]

Pure strontium titanate exhibits a cubic perovskite-type structure at room temperature, but many approaches to break this high degree of symmetry are accessible. The present review summarizes some possible methods by discussing the effects of stoichiometry variation, ion implantation, temperature treatment and external electric fields. Since oxygen vacancies are the most prominent and most mobile defect species in strontium titanate, they play a crucial role also for structural changes due to external influences. Possible functionalities range from tuning of permittivity, band gap and conductivity to field-induced structure changes, which lead to applications as solid-state battery or switchable pyroelectric. [ABSTRACT FROM AUTHOR]

Oxygen delignification can be considered to be the most important part of TCF and ECF bleaching sequences because it allows for cleaner production of pulp. During the process, oxygen gets one electron from lignin in the alkaline condition to form some active oxygen species (AOS), including a superoxide anion radical (O2-•), which is crucial for lignin degradation without damage of carbohydrates. The reaction of O2-• on cellulolytic enzymatic lignin (CEL) from Masson pine was studied. The change in active hydroxyl content after reaction with O2-• was investigated using 31P-NMR. After reaction, the aliphatic hydroxyl and uncondensed type phenol hydroxyl contents decreased, but the content of carboxylic group increased in Masson pine lignin. Through the analysis with HSQC-2D13C-H technology, β-O-4 linkages could be cleaved by O2-•, but β-β and β-5 linkages were observed to be more stable; benzaldehyde and cinnamic aldehyde structures could be oxidized to carboxylic acids by O2-•. Guaiacyl units in lignin were more easily degraded than p-hydroxybenzene units.