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Polyvinyl alcohol (PVA) as an additive has been widely concerned in soil improvement. In the past, the consolidation effect of the PVA in various soils showed obvious differences. However, the reasons for the difference remain unclear. Clay mineral and soluble salt are important components of the soil. Therefore, this study mainly discussed the effects of clay mineral and chloride salt on the unconfined compressive strength (UCS) of PVA-treated soil. The results indicated that CaCl2 and MgCl2 significantly increased the UCS of the PVA-treated soil, whereas NaCl decreased the UCS. Illite and kaolinite had little effect on the UCS, while the UCS first decreased and then increased with the increase in the montmorillonite content. When the MgCl2 or CaCl2 content approached 3%, the soil samples cracked after curing at room temperature for 28 days due to the formation of crystalline water, which sometimes decreased the UCS of the samples. According to the results of multiple linear regression, for the effect of the UCS of the PVA-treated soil, MgCl2 > NaCl > CaCl2 > montmorillonite > kaolinite > illite. The effects of clay mineral and chloride salt on the UCS of the PVA-treated soil mainly depended on the changes in the soil structure, hydrogen bonding, and cross-linking reactions according to the results of the microscopic tests. The PVA as a consolidation material is not suitable for the seaside, and it should be applied to the soil with no more than 2% MgCl2 or CaCl2. [ABSTRACT FROM AUTHOR]

In large eddy simulations (LESs) and scalar filtered mass density functions, a gradient diffusion model is generally used for subgrid-scale (SGS) scalar flux modeling. However, this hypothesis is known to generate evident errors under certain conditions, particularly when the counter-gradient scalar transport effect dominates. Herein, a joint subgrid velocity-scalar filtered mass density function (VSGSSFMDF) method is developed to address this problem. The exact FMDF transport equation is derived in detail. Based on the order of the magnitude analysis and simply Langevin model, the FMDF transport equation is modeled, and a system of stochastic differential equations is, thus, proposed. Theoretical derivation and analysis suggest that both the first- and second-order moments are consistent. A compressible mixing layer and hydrogen/air-reactive mixing layer are simulated to verify the proposed method. Based on the diffusion model, a direct numerical simulation and an LES are performed for comparative verification. A generally reasonable SGS velocity distribution is obtained using the proposed VSGSSFMDF method. Consequently, the counter-gradient scalar transport effect is effectively simulated using this method. Overall, the VSGSSFMDF produces better results than the SFMDF and LES in both cases, particularly in the reactive case. [ABSTRACT FROM AUTHOR]

• The spatial features of rammed pits of the Ming Great Wall were explored. • The representative micro slopes with true rammed pit morphology were found by RF. • The shapes and distribution of rammed pits show more regularity than randomness. • The regularity of rammed pits is derived from the standardized ramming technique. • The rounded heads and rough surfaces of rammers are reflected by rammed pit shapes. In Northwestern China, the Ming Great Wall generally involves multiple layers of rammed earth, and rammed pits with regular spatial characteristics are always distributed on the horizontal interfaces between rammed layers. Obviously, the spatial regularity of rammed pits cannot only reflect the level of ramming technique in the Ming dynasty, but also control the geotechnical properties of rammed layer interfaces (RLIs). Hence, in the present study, one typical RLI with visible rammed pits was obtained from the Ming Great Wall in Yongchang County, Northwestern China, and the corresponding point cloud data were collected by 3D scanning technique. Then, this RLI was reconstructed using numerous micro slopes in ArcGIS, and the distribution maps of micro-slope heights, angles, plan curvatures and profile curvatures were produced as well. Based on these distribution maps and Random Forest (RF) algorithm, those micro slopes which can reflect the true rammed pit morphology (called the representative micro slopes) were identified, and ten zones where the representative micro slopes concentrate were selected as effective analysis domains. Furthermore, within effective analysis domains, the contour lines were generated to show the outline features of rammed pits, and the values of micro-slope heights, angles, plan curvatures and profile curvatures were statistically analyzed to reveal the surface features of rammed pits. Moreover, the distribution features of rammed pits were exhibited by their centroid positions, which can be calculated by the corresponding contour line shapes. Ultimately, this study indicates that rammed pits of the Ming Great Wall show more regularity than randomness in terms of geometric shapes and spatial distribution. Concretely, the outlines of most rammed pits approximate the circular or elliptical shapes. All the rammed pit surfaces are rough rather than smooth, and most of them can be mathematically expressed by quadratic polynomial equations. As for the distribution features, rammed pits are overall distributed in the triangular shapes, and distances between the equivalent centroids of adjacent rammed pits range from 8.95 cm to 17.86 cm. These findings prove that standardized ramming technique was applied in the Ming dynasty, resulting in high-quality construction of the Great Wall. Meanwhile, the rammers used to compact earthen materials possess rounded heads. However, the imperfect polishing of rammers and the inevitable operational errors could also lead to slight spatial randomness of rammed pits. [Display omitted] [ABSTRACT FROM AUTHOR]

Earthen sites with important historical, cultural, artistic, social, and scientific values have been seriously damaged. Basal erosion, which is caused by soluble salts, water runoff, and sand-driving wind, is an extremely threatening erosion pattern for earthen sites. A cushion layer which has a damp-proofing function and good physical and mechanical properties can effectively decrease basal erosion. The primary aim of this study is to investigate material selection for the hydrophobic cushion layer for earthen sites in northwest China. The results indicate that cooked tung oil and sticky rice liquid, traditionally used in China, cannot meet the fundamental requirements of sufficient hydrophobicity for the cushion layer. Although polyvinyl alcohol (PVA) solution and tung oil exhibit similar properties in terms of soil hydrophobicity, water vapour permeability, water resistance, surface hardness, and colour difference for samples with 0.0-1.0% content, the PVA solution is significantly better than tung oil in unconfined compressive strength, deformation modulus, wave velocity, and viscosity. Therefore, the PVA solution should be preferentially selected as a hydrophobic cushion layer material according to the results of this work. When the mixing method is adopted, 0.6-1.0% PVA content is the best choice. [ABSTRACT FROM AUTHOR]

Rammed earth ruins can be regarded as a special soil mass made by humans. Generally, the stability of rammed earth ruins is largely controlled by the morphological characteristics of rammed layer interfaces (RLIs), which have not been well studied yet. In this paper, the Yongchang Section of the Ming Great Wall, a representative of rammed earth ruins in northwestern China, was selected as the study area, and morphological data from three typical RLIs were collected uisng a handheld 3D scanner. For each typical RLI, within three concentric analysis domains with different sizes, the spatial characteristics of microslopes were explored by ArcGIS, and the 3D roughness values along eight analysis directions were calculated. Ultimately, this study indicates that the most notable characteristic of RLIs is the morphological regularity provided by the rammed pits. Thus, within the analysis domains employed here, the spatial characteristics of microslopes and 3D roughness values are size-independent overall. Moreover, the distributions of 3D roughness are basically more isotropic than anisotropic. Additionally, minor bumps on the RLIs were formed by construction, fracturing, and weathering, and they contribute to the limited heterogeneity of the RLI morphology. Thereinto, the weathering-induced can further be divided into minor bumps caused by wind erosion and rainfall erosion. On the whole, RLIs that have undergone wind erosion have significantly higher surface hardness values (60–90 HA) than rainfall-eroded RLIs (< 50 HA). [ABSTRACT FROM AUTHOR]

Erosion diseases often appear on the upper part of the Great Wall of China. Low precipitation, intense solar radiation, and severe soil salinization occur in northwest China, and the migration of salt and damage can be described with respect to the rainfall-radiation cycle. Rainfall and radiation conditions were simulated in the laboratory, and reproduced samples were subjected to cyclic experiments to determine salt migration and the damage progress. Surface hardness and ultrasonic velocity were used to measure the surface damage, and the microstructure damage was determined by computed tomography and scanning electronic microscopy. The results show that under the rainfall-radiation cycle, most of the salt in the upper part, including sulfate, migrates to an area 2–3 cm from, while a small part of the salt, including chloride, moves down into the lower half of the sample. In areas where salt is concentrated, the soil density decreases, cracks develop, and a vulnerable zone appears, reducing the surface hardness and ultrasonic velocity. The concentration of salt causing destruction of the soil structure is the main factor leading to erosion of the upper walls of earthen sites. Infiltration of rainwater is required for the migration of soluble sulfate and the damage to soil on the upper wall. Increasing radiation intensity would greatly accelerate the migration of soluble sulfate and damage to the soil structure. [ABSTRACT FROM AUTHOR]

Background: There have been many studies on the relationship between circRNAs and fat deposition. Although the liver is a central organ for fat metabolism, there are few reports on the relationship between circRNAs in the liver and fat deposition. Methods: In this study, we systematically analyzed circular RNAs in the liver of Ningxiang pigs, at four time points after birth (30 days, 90 days, 150 days and 210 days). Results: A total of 3705 circRNAs were coexpressed in four time periods were found, and KEGG analysis showed that the significantly upregulated pathways were mainly enriched in lipid metabolism and amino acid metabolism, while significantly downregulated pathways were mainly related to signal transduction, such as ECM–receptor interaction, MAPK signaling pathway, etc. Short time-series expression miner (STEM) analysis showed multiple model spectra that were significantly enriched over time in the liver. By constructing a competing endogenous RNA (ceRNA) regulatory network, 9187 pairs of networks related to the change in development time were screened. Conclusions: The expression profiles of circRNAs in Ningxiang pig liver were revealed at different development periods, and it was determined that there is differential coexpression. Through enrichment analysis of these circRNAs, it was revealed that host genes were involved in metabolism-related signaling pathways and fatty acid anabolism. Through STEM analysis, many circRNAs involved in fat metabolism, transport, and deposition pathways were screened, and the first circRNA–miRNA–mRNA regulation network map in Ningxiang pig liver was constructed. The highly expressed circRNAs related to fat deposition were verified and were consistent with RNA-Seq results. [ABSTRACT FROM AUTHOR]

• Dissolution of calcite, plagioclase and K-feldspar caused major elemental loss (to solutions) of Na, K and Ca in the BTG. • Weathering patterns were linked to seasonal hydrological changes affected by both reservoir filling and groundwater system. • More evidence for surface illitization of smectite in natural alkaline environments was provided. Alkaline environments are common in arid and semi-arid regions in northwestern China and have preserved quantities of rock heritages along the Silk Road. In contrast to the frequently reported weathering mechanism of stone heritages in acidic conditions, mineral weathering mechanism (especially the transformation mechanism of smectite) in natural alkaline environments still remains to be evaluated. To deepen the understanding of weathering in such an environment, research idea from critical zone science was applied to investigate the element transport and mineral transformation from protolith (interbedded sandstone and conglomerate) to regolith in a world cultural heritage, Bingling Temple Grottoes (BTG), in northwestern China. From geochemical and mineralogical characterizations on boreholes, excavated profiles, fractures and cliff surface, we found that dissolution of calcite, plagioclase (anorthite, albite) and K-feldspar (orthoclase) caused major elemental loss of Na, K and Ca (to aqueous solution) in the BTG, and elements of Mg and Fe mostly retained in solid materials. Characterizations on the cliff surface demonstrated higher extents of element depletion and mineral weathering and lower ultrasonic P -wave velocities in sandstone than in conglomerate, and in the bottom sandstone layers (located in the capillary zone and exposure to rain scouring) than in upper sandstone layers (located in the cave and free of precipitation). The transformation of smectite from protolith to regolith follows the sequential reactions: dehydrated smectie → bihydrated smectite → randomly interstratified illite/smectite → illite. Such transformation pathway is favored by alkaline pH and wetting–drying cycles frequently occurred at the BTG. Typical weathering patterns such as clay swelling damage, efflorescence, salt precipitation, etc., are highly-linked to seasonal changes in the hydrological process influenced by both reservoir construction and groundwater system. Our study provides more evidence for the illitization of smectite in natural alkaline environments and highlights the hydrological impacts on weathering patterns of rock grottoes. [ABSTRACT FROM AUTHOR]

Earthen plasters have been widely used in historical buildings such as grottoes, which have high historical, artistic, scientific, social, and cultural values. In order to study the influence of the material composition of plasters on its physical performance, a total of seven different types of earthen plaster specimens were made using Dengban clay and six admixtures (quartz sand, two types of vegetal fibers, and three types of hydraulic limes), and the surface water absorption properties, hygrothermal properties, surface strength (surface hardness, surface cohesion, and surface impact resistance), color difference, and radial shrinkage of all plasters were systematically investigated and compared. The results show that the addition of sand, vegetal fibers, and hydraulic limes all changed the surface water absorption, thermal conductivity, and water vapor permeability of plaster, and inhibit the radial shrinkage during the curing process. Compared to the other admixtures, sand had the least effect on the overall performance of plasters. Both types of vegetal fibers can greatly improve the impact resistance of plaster surface, but due to the formation of microcracks on the surface of the plaster with wheat straw fibers, its water absorption is much higher than that of the plaster with hemp fibers. The addition of three types of hydraulic limes changed the surface color of the plaster to some extent, and the water repellency of the plaster surface will be enhanced due to the carbonation of hydraulic lime. • The physical performance of seven types of earthen plasters was investigated. • The carbonation process enhances the water repellency of the plasters with hydraulic lime added. • The addition of vegetal fibers has greatly improved the impact resistance of the plaster surface. • The addition of hydraulic lime has an effect on the surface color (ΔE > 3). [ABSTRACT FROM AUTHOR]

Having extremely high artistic, scientific and social values, earthen sites are widely distributed in China and are important human cultural relic resources. Due to accumulated natural erosions (from rain and wind) and human activities (destructive activities of human beings in history and modern times), however, earthen sites have been greatly damaged, and many sections have even been absent, so that they are seriously threatened by extinction. Under these circumstances, acquiring the conservation status of earthen sites is a vital prerequisite for the subsequent targeted protection. In this paper, as a world-renowned heritage site, the castles of the Ming Great Wall located in Qinghai Province were selected as the research object. A novel indicator, namely the linear absent section ratio (L-ASR), was proposed, and its value was classified into five levels to quantitatively characterize the specific conservation status of such sites, including excellent (E) (0–10%), good (G) (10–25%), fair (F) (25–50%), poor (P) (50–75%), and very poor (VP) (75–100%). Based on the assessment results, the castles with excellent status constituted the minimum proportion, while the castles with very poor status represented the largest percentage, reflecting the grave situation of earthen sites. Furthermore, by applying population distribution models to the linear fitting combined with the population density (PD), a positive correlation between PD and L-ASR was obtained to reveal the anthropogenic influence on the destruction of earthen sites. Principal component analysis (PCA) was utilized to provide a far richer understanding of which factors correlate most strongly with deterioration. This study provides a new thought to quantitatively characterize the preservation conditions of earthen sites and also indicates the effect of human activities on the damage of earthen sites from a population density perspective, which is potentially used for the analysis of more various types of architecture with different construction techniques. Hence, this approach is beneficial to the overall damage assessment of earthen sites, and also meaningful to their further preservation and protective planning. [ABSTRACT FROM AUTHOR]

Soil wettability is an important property that affects the behaviour of fine-grained soils. Previous studies have shown that hydrophobicity induced by organic or silane additives may affect the soil-water retention curve (SWRC). However, current findings regarding the effect of hydrophobicity on the SWRC are controversial. Previously, organic or silane additives were assumed to change only the soil wettability. Nevertheless, this study shows that polyvinyl alcohol (PVA) can change the hydrophobicity, pore size distribution (PSD), and specific surface area (SSA) of soil, thus affecting the SWRC. PVA-treated soil is hydrophobic when cured at 20 ℃, but hydrophilic when cured at 100 ℃. No thermal degradation is indicated in the PVA at 100 ℃ based on thermogravimetric analysis and a comparison of mass loss, and the sole difference between the PVA-treated soils cured at 20 and 100 ℃ is their wettability. This study managed to make the hydrophobicity caused by PVA to become an independent variable separated from the PSD and SSA by controlling the ambient temperature. The wetting and drying curves are measured under isopiestic humidity control in the high-suction domain (2.7–298.7 MPa), whereas pressure plates are used for the drying curves in the low-suction domain (0–800 kPa). The results obtained indicate that soil hydrophobicity significantly accelerates drainage when the matric suction is between 100 and 400 kPa, and an increase in PVA content increases the water retention capacity of soil. When the matric suction exceeds 2.7 MPa, the effect of soil hydrophobicity on the SWRC of the soil weakens. At this time, the SWRC is dominated by the van der Waals force, and the SSA contributes significantly to the process. Additionally, this study enables some controversial findings from previous studies to be explained, which is of great significance in soil and agriculture sciences. • A new method to isolate effect of hydrophobicity from other factors is proposed. • Soil hydrophobicity enhances water drainage in the low-suction domain. • Soil hydrophobicity has a weak effect in the high-suction domain. • The reason for the controversial conclusions in past studies is discussed. [ABSTRACT FROM AUTHOR]

Water-salt migration is an important reason for the development of basal erosion which seriously threatens the conservation of earthen sites. Studies in cutting-off or redirection of the water-salt migration path become vital. Polyvinyl alcohol (PVA) composite soil with extreme hydrophobicity shows the potential as the cushion layer with the damp-proof function, but the feasibility of preventing basal erosion based on the PVA cushion layer still lacks verification. In this study, for the embedded and non-embedded PVA cushion layers, water-salt distribution and morphology of earthen wall after repeated injection of salt solution were compared. The results showed that PVA cushion layer changed the water-salt migration path and promoted the accumulation of soluble salt on the ground outside the wall rather than the bottom of cushion layer, which effectively prevented basal erosion. A numerical model based on HYDRUS-2D confirmed that a partial laying of hydrophobic cushion layer under the wall cannot effectively prevent the water-salt migration, and a full laying of cushion layer should be adopted to prevent basal erosion. The cushion layer was recommended to extend towards the direction of the earthen wall instead of towards the sides, which also resisted the destructive effects of sand-driving wind and runoff erosion. • Basal erosion caused by water-salt migration is directly confirmed. • Water-salt distribution for models with/without PVA cushion layer is explored. • PVA cushion layer can inhibit basal erosion. • Reasonable laying modes of the hydrophobic cushion layer is presented. [ABSTRACT FROM AUTHOR]

Grottoes are widely distributed along the ancient Silk Road in Northwest China, and wall paintings are among the most precious cultural relics in these grottoes. On-site investigation of some grottoes has revealed that these wall paintings are painted on earthen plaster and that most of them have a double-layer structure of plaster, i.e., a base coarse plaster layer (with wheat straw added) and a surface fine plaster layer (with hemp fibers added). Meanwhile, studies regarding the improvement in shrinkage and cracking behaviors via ancient plaster craftsmanship have been scarce. To investigate the specific effects of different material compositions on the shrinkage and cracking properties of plaster during desiccation, a series of laboratory shrinkage and cracking tests is conducted on plaster specimens composed of Dengban clay and quartz sand, vegetal fibers, and a potential restoration material (i.e., calcined ginger nut), respectively. The results show that adding sand and vegetal fibers can significantly increase the shrinkage limit of Dengban clay and inhibit its volume shrinkage and that vegetal fibers play an important role in the inhibition of surface cracking on plaster. Sand inhibits shrinkage by forming a skeleton in soil and reducing the formation of primary cracks. Fibers inhibit soil shrinkage by overcoming the suction between soil particles and preventing the formation of primary cracks. However, wheat straw cannot deform with the shrinkage of soil (e.g., hemp fibers); consequently, many subcracks appear around the wheat straw on the surface of coarse plaster. As a typical lime-based restoration material, calcined ginger nut paste presents slight shrinkage and a low surface crack ratio during desiccation, which demonstrates its good application prospect in plaster restoration. • Different types of plaster specimens are prepared based on the original composition. • Sand and vegetal fibers can significantly increase the shrinkage limit of Dengban clay. • Vegetal fibers are more effective in inhibiting surface cracking. • Calcined ginger nut paste shows slight shrinkage and a low surface crack ratio during drying. [ABSTRACT FROM AUTHOR]

• Sticky rice can inhibit the carbonation reaction of lime-treated soil. • The outer part of the sample had a higher carbonation than the inner part. • Binding and inhibition effects of sticky rice adjusted strength of lime-treated soil. Earthen sites with important historical, artistic, social, cultural, and scientific values have suffered serious damage due to long-term influences from various natural factors. The sticky rice and lime composite shows the potential to be applied to the protection of earthen sites. The carbonation of lime has a significant impact on the engineering properties of earthen sites. The main purpose of this study is to investigate the effect of sticky rice on the carbonation reaction of lime-treated soil in earthen sites. The results indicated that sticky rice can inhibit the carbonation reaction of lime, resulting in a reduced calcium carbonate content. The inhibition effect of sticky rice on carbonation reaction of lime could be attributed to the limitation of gaseous water and CO 2 gas diffusion. Sticky rice had both binding effect and inhibition effect on lime-treated soil, and its mechanical properties depended on the dominant effect after these effects cancelled each other. When the lime content was ≤6%, the addition of sticky rice can increase the strength of soil. When the lime content was >6%, however, the addition of sticky rice resulted in a decrease in strength. In addition, the carbonation of the outside of the cylindrical sample was higher than that of the inside. These findings can increase the understanding of protecting earthen sites with sticky rice and lime composite, and optimize the application of sticky rice and lime composite. [ABSTRACT FROM AUTHOR]

• The capillary barrier effect was applied to mitigate the secondary salt deterioration in the restored earthen sites. • Arya-Paris model and Fredlund-Xing's model were combined to predict the capillary barrier effect at the interface between earthen site soil and repair soil. • The prediction results were verified by water-salt migration test and mercury intrusion porosimetry. • Increasing the content of coarse particles in repair soil can effectively reduce the risk of secondary salt deterioration in the restored earthen site. Basal erosion is one of the most typical salt deteriorations of earthen sites in arid and semi-arid areas. Its formation is mainly related to the water and salt migration and enrichment at the bottom of earthen sites walls, and can cause collapse of site walls. Rammed roof-propping reinforcement is the main repair technology for the basal erosion of the earthen sites, but there is a risk of secondary salt deterioration in the repaired area due to the subsequent water and salt migration. Based on the capillary barrier theory, this study regulates the particle size composition of repair soil to explore repair materials that can effectively mitigate the secondary salt deterioration. Firstly, Arya-Paris model and Fredlund-Xing's model were used to convert the particle size distribution curves (PSDC) of soil with different particle composition into soil–water characteristic curves (SWCC), to preliminarily judge the capillary barrier potential of different soil structures. Then carry out water-salt migration test and mercury intrusion porosimetry test to verify the predictions. The research shows that when repair soil is coarser than earthen site soil, it can form an effective capillary barrier to block the capillary rise of water and salt, thus reducing the secondary salt deterioration in the repaired area. When repair soil is finer than earthen site soil, it will promote the capillary rise of water and salt, thus aggravating the salt deterioration in the repaired area. It is proposed to use the repair material of adding 20% sand on the basis of the original earthen site soil particle composition for the rammed roof-propping reinforcement of the earthen sites. [ABSTRACT FROM AUTHOR]

Earthen sites (i.e., ancient earthen buildings) with important historical, cultural, artistic, social, and scientific value have been seriously damaged. Soil treatment with chemical additives can decrease the degradation rate of earthen sites. In the past, polyvinyl alcohol (PVA) and quicklime as chemical additives were studied separately for the protection of earthen sites. In arid and semi-arid northwest China, the early strength of the lime-treated soil may be insufficient due to an inappropriate reaction environment, and the PVA as the additive can quickly increase the soil strength. However, calcium carbonate has been proven to not be decomposed for hundreds of years, while there is still a lack of experimental evidence to show that the PVA cannot be decomposed in decades. The PVA and lime as the additives show the potential to make up for the defects each other. Therefore, the physical and mechanical properties of the PVA and lime composite soil are analysed, and the microscopic properties of the composite soil are discussed in this study. The results show that the addition of the PVA decreases water vapour permeability and pore size, which causes a delay in the carbonization reaction of lime, but it acts as a cementing agent to improve soil strength before the lime appropriately reacts. The addition of quicklime can decrease the hydrophobicity of the PVA-treated soil. The mixing of these two materials is conducive to the colour control of the sample. For the composite soil applied to earthen sites in northwest China, the optimal ratio is 10% lime and 1.0% PVA. [ABSTRACT FROM AUTHOR]

• The protective effects of sticky rice and lime composite are evaluated. • The relationship between macroscopic properties and microstructure is established. • The feasibility of protecting earthen sites with sticky rice and lime is discussed. Earthen sites have important historical, artistic, social, cultural, and scientific values. However, due to the extreme natural environment, they have suffered serious damage. The sticky rice and lime composite is one of the most important technological inventions in Chinese architectural history, which is an alternative material for the protection of earthen sites. In the past, the mechanical and microscopic properties of sticky rice and lime composite as binding material have been discussed. However, these properties are not sufficient to evaluate the feasibility of protecting earthen sites with sticky rice and lime composite. In this study, 25 groups of soil samples were prepared at five different lime contents (i.e. 0%, 3%, 6%, 9% and 12% by dry weight of sample) and five different sticky rice contents (i.e. 0.0%, 0.5%, 1.0%, 1.5% and 2.0% by dry weight of sample), and several important characteristics of the samples such as drying shrinkage, colour difference, surface hardness, unconfined compressive strength (UCS), and water vapour permeability are investigated comprehensively. Scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) were used to study the microstructure of samples. Then, the feasibility of protecting earthen sites with sticky rice and lime composite was systematically evaluated. The results indicate that the effectiveness of sticky rice and lime composite is better than that of their individual application. The optimal formula is 6% lime and 0.5% sticky rice for the protection of earthen sites when above indicators are compared. The surface fractal dimension builds bridges between microstructure and macroscopic properties of the soil with sticky rice and lime. Surface hardness and UCS are positively related to the surface fractal dimension, while water vapour permeability is negative related to the surface fractal dimension. This research further provides insights into the potential application of traditional Chinese inorganic–organic composite for protecting earthen sites in arid and semi-arid regions of northwest China. [ABSTRACT FROM AUTHOR]

• PVA-treated soil is confirmed to prevent water-salt capillary rise. • Effectiveness of 1.0% PVA-treated soil is best. • Interface effects are proposed to explain experimental phenomena. • Capillary rise of layered soil is described by modified Green-Ampt model. In the loess region of northwest China, the accumulation of soluble salt in the soil due to the capillary rise of water often damages earthen buildings. Thus, studies on the cutting off of the capillary-rise path are vital. As a hydrophobicity inducer, polyvinyl alcohol (PVA) solution with water as the solvent has the potential to function as a barrier. This study mainly aims to evaluate the feasibility of using PVA-treated soil as a waterproof layer to prevent water-salt capillary rise through soil column experiments, and the effects of the waterproof layer thickness, waterproof layer position, PVA content, ambient temperature, and type of salt solution on the capillary action. The results indicate that a 1.0% PVA-treated soil with extreme water repellency (i.e. dried at 20 °C) can perfectly prevent the water-salt from migrating to the top of the sample, regardless of the waterproof layer position, waterproof layer thickness, and type of soluble salt. For a 0.5% PVA-treated soil dried at 20 °C, the lower waterproof layer prevents the water-salt capillary rise, while the middle and upper layers exhibit less effectiveness. However, the PVA-treated soil that loses its hydrophobicity after a treatment at 100 °C cannot prevent the water-salt capillary rise, confirming that the prevention of capillary rise is due to the soil hydrophobicity. The waterproof layer thickness and type of soluble salt are less significant than the waterproof layer position, PVA content, and ambient temperature. This study proposes a modified Green-Ampt model to describe the capillary rise, and the hydraulic conductivity and pore size are obtained using the modified model. These parameters and the interface effect are used to explain the experimental results. Finally, the application of PVA-treated soil as a waterproof layer to inhibit water-salt capillary rise is illustrated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Properties of CGN- and NHL-based pastes were investigated and compared. • The UCS of the CGN-based specimens improved significantly after aging for 90 days. • CGN-based pastes exhibited similar pore size distribution to the original plaster. • The strength mainly depended on the morphology of the hydrate and carbonate. In order to study the consolidation mechanism of traditional lime-based binders in the restoration of earthen plaster, the mechanical strength, hydration kinetics, and microstructure properties of calcined ginger nut (CGN)- and natural hydraulic lime (NHL)-based pastes were systematically investigated and compared. The results showed that CGN had good compatibility with clayish earth. Compared with the NHL-based pastes, the CGN-based pastes exhibited a higher late-stage compressive strength, lower heat release, denser microstructure and similar pore size distribution compared to the original plaster. [ABSTRACT FROM AUTHOR]

Owing to the advantages of cost-effectiveness, compactness, and the avoidance of complicated camera synchronization, single-camera three-dimensional (3D) digital image correlation (DIC) techniques have gained increasing attention for deformation measurement of materials and structures. In the traditional single-camera 3D-DIC system, the left and right view images can be recorded by a single camera using diffraction grating, a bi-prism, or a set of planar mirrors. To further improve the measurement accuracy of single-camera 3D-DIC, this paper introduces a single-camera four-view imaging technique by installing a pyramidal prism in front of the camera. The 3D reconstruction of the measured points before and after deformation is realized with eight governing equations induced by four views, and the strong geometric constraints of four views can help to improve the measurement accuracy. A static experiment, a rigid body translation experiment, and a four-point bending experiment show that the proposed single-camera 3D-DIC method can achieve higher measurement accuracy than the dual-view single-camera 3D-DIC techniques and that the single-camera 3D-DIC method has advantages in reducing both random error and systematic error. [ABSTRACT FROM AUTHOR]

On the premise of following the concept of culture heritage conservation, the technique of wooden bolt anchorage plays an important role in the conservation of rammed earthen sites. The existing researches on single anchoring cannot reflect the mechanical behaviors of an anchor group. To solve this problem, this study proposes a load-transfer method achieved by a universal joint combined with a load-bearing platform. Three rammed earth models were tested by continuous loading, with embedded length, bolt interval, and margin as variables. The failure mode, ultimate pulling resistance, load–displacement relationship, and interfacial strain distribution of the anchorage system were analyzed. Results show that the two bolts present sequential failure. Meanwhile, the failure of wooden bolts is not in a single mode; instead both interfacial debonding and soil-bearing capacity loss were observed in soil at the same time. The bolts are mostly in plastic-slipping state under working conditions. The strain is unevenly distributed at the bolt—grout interface and highest near the loading side. Spacing effect and marginal effect are important factors affecting the pulling resistance of two bolts, and their importance is higher than the quality of a single bolt. In addition, numerical simulations on behaviors of two wooden bolts, considering the interval distance, margin distance, embedment length, and layered property of rammed earth, were established by "interface" element, which supplemented and expanded the model test results. Results of this paper could provide deeper understanding of the macroscopic performance and internal mechanism of a two-bolts group. [ABSTRACT FROM AUTHOR]

The filtered mass density function (FMDF) model has been employed for large-eddy simulations (LES) of compressible high-speed turbulent mixing and reacting flows. However, the mixing model remains a pressing challenge for FMDF methods, especially for compressible reactive flows. In this work, a temporal development mixing layer with two different convective Mach numbers, M c = 0.4 and M c = 0.8 , is used to investigate the mixing models. A simplified one-step reaction and a real hydrogen/air reaction are employed to study the mixing and turbulence-chemistry interaction. Two widely used mixing models, interaction by exchange with the mean (IEM) and Euclidean minimum spanning tree (EMST), are studied. Numerical results indicate that no difference is observed between the IEM and EMST models in simple reaction flows. However, for hydrogen/air reactions, the EMST model can predict the reaction more accurately in high-speed flow. For mixing models in compressible reactive flows, the requirement of localness preservation tends to be more essential as the convective Mach number increases. With the increase of compressibility, the sensitivity of the mixing model coefficient is reduced significantly. Therefore, the appropriate mixing model coefficient has a wider range. Results also indicate that a large error may result when using a fixed mixing model coefficient in compressible flows. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hoeffding Tree is a promising landslide susceptibility model based on ROC and AUC. • Bayes Network and Logistic Model Tree were applied for comparison. • Correlation analysis of conditioning factors was completed by Frequency Ratio. • Landslide susceptibility maps of Muchuan County and the county town were produced. Landslides, one of the most common hazards around the world, have brought about severe damage to life and property of human. To prevent and mitigate landslides, various models have been introduced to assess landslide susceptibility. In this paper, Hoeffding Tree (HT), a prevailing data stream mining algorithm, was employed to predict landslide susceptibility in Muchuan County, China for the first time. Meanwhile, Logistic Model Tree (LMT) and Bayes Network (BN) were applied to produce landslide susceptibility maps for comparison. The model performances were evaluated by Receiver Operating Characteristic (ROC) curves and areas under the curves (AUC). To obtain landslide inventory map, 279 landslides data was collected, and training and validation datasets were randomly divided with a proportion of 70% to 30%. Furthermore, twelve conditioning factors (altitude, slope angle, profile curvature, plan curvature, slope aspect, distance to roads, distance to rivers, TWI, NDVI, soil, land use and lithology) were selected to construct landslide susceptibility models. Moreover, correlations between conditioning factors and landslides were analyzed using Frequency Ratio (FR). The results showed landslides are prone to occur in areas where human activities concentrate, and all three models exhibited satisfying performances. Concretely, for training dataset, LMT model showed the highest AUC (0.854), followed by HT (0.726) and BN (0.709). However, for validation dataset, LMT and BN models generated similar AUC values (0.761 and 0.764 respectively), and the highest AUC value belonged to HT (0.802). The distributions of landslide susceptibility zones revealed that the interior of county town is mainly seated in low and very low susceptibility zones, whereas regions close to the border suffer high and very high landslide risk. The results acquired in this paper are significant to landslide prevention and urban planning in Muchuan, China. Additionally, this study proved that HT model is a promising classifier for landslide susceptibility modeling. [ABSTRACT FROM AUTHOR]

While the macroscopic mechanical properties of earthen-site soils have undergone extensive experimental and modeling studies, few research efforts focus on the relationship between the overall mechanical behavior and micro-pore structure. We developed a microstructure-based finite element model to investigate the influence of micro-pore structure on the macroscopic mechanical behavior of earthen-site soils. Scanning electron microscopy images of the untreated and consolidated soils were processed to compare the changes in equivalent diameter, sphericity, and porosity of the soils after consolidation. According to the pore parameter range of the untreated and consolidated soils, the effects of micro-pores on the soil behavior are specifically conducted under both static and dynamic loads. The relationships between pore characteristics and stiffness, strength, and ultrasonic wave velocity are established. [ABSTRACT FROM AUTHOR]

• A SMOTE approach was proposed to handle imbalanced data of hazards levels. • SMOTE was integrated with Gaussian process for the prediction of hazards levels. • A real-world example is used to illustrate and validate the proposed approach. • Results from different data generation approaches are compared with that of SMOTE. • Results from different machine learning methods are compared with that of GP. Cultural soil heritages (CSHs) are artifacts with historical, artistic, and scientific significance; however, they are vulnerable to various hazards, such as weathering, fractures, hollowing, collapses, and gullies. This is especially true for those CSHs exposed to the outdoors. Due to the large number of CSHs sites within China, managing and protecting these heritages with the aid of detailed on-site investigations is time-consuming and expensive. Consequently, evaluating the spatial distribution and degree of hazards developed in all these heritages becomes impractical. To address this issue, this paper developed a Gaussian process classification (GPC) method to predict the spatial distribution of typical hazards (i.e., weathering, fractures, hollowing, collapses, and gullies) and the development level of each hazard from eight environmental factors (e.g., annual relative humidity and annual sunshine time) and a limited number of investigation data. As the number of investigation data for different levels of each hazard is usually imbalanced and sparse, this study proposed a synthetic minority oversampling technique (SMOTE) with GPC to form the SMOTE-GPC method. A real-world example is used to illustrate this approach. Results from real-world data demonstrated that the proposed method achieved an F 1 score, precision, recall, and Cohen's kappa with values greater than 0.93 in both the training and testing datasets, indicating its good performance. [ABSTRACT FROM AUTHOR]

While experimental explorations to consolidate earthen-site soils using composite materials have obtained desirable reinforcing effect, few modeling efforts were conducted to reveal how microstructures of consolidated soils affect their effective stiffness and strength. The current study develops a multiscale modeling technique to quantify the stiffening and strengthening effects of consolidants to earthen-site soils. Specifically, a micromechanics-based finite element method is applied to simulate the homogenized constitutive relations of the untreated and consolidated soils, based on the microstructures from scanning electron microscopy images and image-processing procedures. Multiscale models are used to examine the influence of input properties of consolidants on the sensitivity of mechanical properties of the earthen-site samples. Comparison between modeling and experimental results shows a satisfactory agreement. The macroscopic mechanical properties of soils are remarkably affected by their microstructures. This study demonstrates the feasibility of integrating scanning electron microscopy and image processing technology into the finite-element modeling for stiffening and strengthening analysis of consolidated earthen-site soils. [ABSTRACT FROM AUTHOR]

Hydrogen attack is the major failure cause of hydrogen equipment breakdown maintenance. Especially, common problems like cracks frequently occur but are challenging to find while operating, presenting an issue for safety and production. In the process of hydrogen damage evolution, a method for defect state recognition is proposed in this paper. Acoustic emission (AE) technology is used for inspecting the entire hydrogen charging process. The characteristic parameters including the counts and duration of the AE signals are first preprocessed, and the current damage states such as the dislocation propagation, and the occurrence of cracks are identified. Then, a deep learning convolutional neural network is used to create a hydrogen defect recognition (HDR) model with the input of a short-time Fourier transform for the feature vector extraction of various damage status AE signals. Finally, the hydrogen defect recognition experiment revealed that HDR is better in classification accuracy at 98.37% due to dislocation propagation and cracks identification. The study can provide an online damage recognition approach for damage state early warning and evaluation to guarantee hydrogen equipment safety operation. • Monitor the hydrogen damage process using acoustic emission detection technology. • Characteristics of the acoustic sources in hydrogen damage process are studied. • Neural network is used for hydrogen damage signal recognition and diagnosis. • STFT transform image is used as the neural network model input. [ABSTRACT FROM AUTHOR]

Although nondestructive ultrasonic technologies have been applied in laboratory and field tests in the field of heritage conservation, few studies have quantified the relationship among the real microstructures, micromechanical properties, and macroscopic acoustic responses of earthen-site soils. This paper develops a micromechanics-based multiscale model for quantitatively exploring the ultrasonic propagation characteristics of elastic waves in untreated and consolidated earthen-site soils. Scanning electron microscope images and image processing technology are integrated into the finite-element simulation. The effects of microstructure and wave features on the acoustic characteristics of soils are quantitatively investigated under pulsive loading. The simulation results of untreated and consolidated soils are efficiently compared to ultrasonic test data. It is demonstrated that the integration of microstructure image processing and multiscale modeling can predict the ultrasonic pulse velocity well, which improves the accuracy of laboratory testing and field monitoring and better serves the evaluation and implementation of engineering practice in the field of heritage conservation. [ABSTRACT FROM AUTHOR]

• The morphology of differential weathering is digitized by 3D laser scanning. • The differential weathering features are characterized by the roughness indexes. • How spatial features of walls affect the differential weathering is discussed. • The classification of differential weathering degree is explored preliminarily. Earthen heritage sites have been undergoing lengthy surface weathering since they were built, which can pose a severe threat to the protection and utilization of these cultural treasures. Especially for differential weathering, one of the most common surface weathering patterns of earthen heritage sites in northwestern China, has not been well studied yet. Hence, in this paper, Suoyang Ancient City was selected as the study area, and six analysis domains (S1 to S6) exhibiting various differential weathering degrees were determined on wall faces and their morphological data were collected by a 3D laser scanner. Based on the point cloud data, the morphology of each domain was digitalized and reconstructed, and ten typical profiles were selected for roughness analysis. Concretely, for these profiles, six roughness parameters, including average asperity inclination (A i), mean curvature (R′da), textural slope parameter (Z 2), roughness coefficient (R p), self-affine fractal dimensions (A and D) and directional roughness metric (G (i)) were calculated to characterize their differential weathering features. The results show that the wall with a higher differential weathering degree has greater values of R p , G (i), A and D. It can also be found that different roughness indicators can reflect different wall surface morphological characteristics. In addition, the main driver of differential weathering developing is the prevailing sediment-laden wind, and the degree of differential weathering is also affected by the building techniques, wall endowment environment, wall orientation and morphology. Finally, according to the roughness values and wall surface morphology, the differential weathering degrees were classified into five grades (from level I to level V). In this case, the differential weathering degrees of S2 (level IV) and S5 (level IV) are the highest, followed by S3 (level III), S6 (level III), S1 (level II) and S4 (level II) respectively. Overall, the proposed approach based on 3D scanning and surface roughness is feasible to characterize the differential weathering degree, contributing to better prevention and mitigation of damage on earthen heritage sites. [ABSTRACT FROM AUTHOR]

A remarkable risk in the field of rock engineering is the natural exposure of low-grade metamorphic rock to the freeze-thaw process. Examples of such materials are slate and phyllite, which are employed approximately mountainous permafrost zones. In order to study the weathering processes and mechanisms in low-grade metamorphic rock following freeze-thaw weathering processes, the freeze-thaw cycles were applied. Accordingly to this process, low-grade metamorphic rock partially or completely deteriorates, and mechanical properties, microstructure, and mineral content changes are commonly associated with freeze-thaw processes. This study shows that, following numerous freeze-thaw cycles processes, the quality, wave velocity, and compressive strength of rock reduce; calcite, mica, feldspar, and pyrite contents decrease; and clay minerals and gypsum content increase. Furthermore, the study also demonstrated that the changes in quality, wave velocity, and compressive strength caused by weathering of the rock followed the sequence slate > phyllite. However, the mineral contents of slate and phyllite alter in the same way. Because of this increase in volume and subsequent F-T cycles, new cracks form on the surfaces of pores due to outward pressure, and a lot of water is absorbed by clay minerals. The amount of water increases once again due to freezing as the temperature falls below zero degrees Celsius. This course duplicates with cyclic temperature changes and causes deterioration of low-grade metamorphic rock materials. By analysis of an examination of the damage variables based on wave velocity, it is possible to conclude that mineral changes during the freeze-thaw effect may make for the formation of voids and the deterioration of metamorphic rock. This research contributes to a better understanding of weathering processes and mechanisms of low-grade metamorphic rock following freeze-thaw weathering processes. [ABSTRACT FROM AUTHOR]

Subarachnoid hemorrhage (SAH) is one of the common clinical neurological emergencies. Its incidence accounts for about 5–9% of cerebral stroke patients. Even surviving patients often suffer from severe adverse prognoses such as hemiplegia, aphasia, cognitive dysfunction and even death. Inflammatory response plays an important role during early nerve injury in SAH. Toll-like receptors (TLRs), pattern recognition receptors, are important components of the body's innate immune system, and they are usually activated by damage-associated molecular pattern molecules. Studies have shown that with TLR 4 as an essential member of the TLRs family, the inflammatory transduction pathway mediated by it plays a vital role in brain injury after SAH. After SAH occurrence, large amounts of blood enter the subarachnoid space. This can produce massive damage-associated molecular pattern molecules that bind to TLR4, which activates inflammatory response and causes early brain injury, thus resulting in serious adverse prognoses. In this paper, the process in research on TLR4-mediated inflammatory response mechanism in brain injury after SAH was reviewed to provide a new thought for clinical treatment. [ABSTRACT FROM AUTHOR]

• The development difference of scaling off on the sunward side and nightside of earthen sites was revealed. • The new indicators of salt migration gradient (SMG) and normalized shrinkage rate (NSR) were proposed. • The mechanism of salt difference and heterogeneous shrinkage on different building orientations were indicated. • Environmental monitoring was comprehensively analysed to explain the development difference of scaling off on different building orientations. Scaling off is one of the most representative deterioration types of earthen sites, severely causing their damage with a characteristic binary structure consisting of the crusted and loose layers. Exploring the development cause of scaling off is the key premise for targeted protection of earthen sites. Thus far, numerous researchers focused on environmental and rammed earth factors; however, the development difference of scaling off on different building orientations has not been studied. Therefore, this study aims to reveal the development difference of scaling off on the sunward side and nightside of earthen sites. In this study, 15 earthen sites situated in NW, China, are chosen and the scaling off is investigated in the field to collect characteristic values of the binary structure of scaling off on two sides of the wall. Subsequently, the previous built-up evaluation system is applied to calculate the development degree of scaling off to show its discrepancy rate (DR) on distinct building orientations. Additionally, the samples of rammed earth in different layers are collected and indoor geotechnical tests are performed to obtain the evaluation indicators. Combined with the binary structure and rammed earth properties, the salt differentiation and heterogeneous shrinkage of soils in different layers are quantificationally reflected. Finally, the temperature and humidity of three representative earthen sites are monitored for 24 h after rainfall. By analysing the environmental change, the greater amplitude of environmental change for the sunward side is found; this is an important driving force for salt migration, which leads to the difference in binary structures. This study reveals the development difference of scaling off on the sunward side and nightside from the quantitative perspective, which supplements current research contents on characteristics and mechanism of earthen sites deteriorations, beneficial to their further protection work. [Display omitted] [ABSTRACT FROM AUTHOR]

As a renewable energy source, biomass has the potential to replace non-renewable, fossil fuels. However, the disposal of the waste biomass ash (generated during energy generation) needs to be studied. While prior studies attempted to utilise composite additives containing biomass ash for soil, the introduction of other additives, such as cement, was an environmental burden. By employing biomass ash composition as the sole additive for strengthening purple soil under various curing conditions using high-temperature treatment, this study maximised its utilisation. The results showed that the unconfined compressive strength (UCS) varied across different curing conditions as the biomass ash content increased. After high temperature treatment at 800 ℃, the biomass ash consistently reinforced purple soil under all the curing conditions. However, the biomass ash stabilisation mechanism differed between dry and humid curing conditions. Under dry curing conditions, the UCS increase depended on the cementing effect of soluble salt and/or insoluble calcite; under humid curing conditions, the UCS change was attributed to the damage to clay minerals, contact mode, and cementing effects of multiple components. Therefore, the 800 ℃ temperature-treated biomass ash can be used alone to reinforce purple soil, inhibiting the soil-water loss. This study presents a novel avenue for utilising waste, biomass ash, with considerable implications for environmental protection and soil stabilisation. • Purple soil can be reinforced by biomass ash treated at 800 ℃. • Curing condition has a significant impact on stabilising effect. • Stabilisation mechanisms differ between dry and humid curing conditions. • A novel avenue to utilize waste biomass ash is provided. [ABSTRACT FROM AUTHOR]

Bubble rupture is one of the main acoustic emission (AE) sources for corrosion detection and the study of its acoustic characteristics is of great significance for corrosion identification. However, the stress state affects the form of bubble rupture, causing different acoustic characteristics. In this paper, the acoustic signal characteristics of two forms of bubble rupture and drag phenomena are investigated and the process of bubble rupture both near to and away from the metal surface is studied, mainly through theoretical calculation, numerical simulation and experimentation. A theoretical model of bubble rupture is established according to the volume of fluid (VOF) method. The finite element method is used to solve the plate displacement at the interface. Stress pulse theory is applied to calculate the AE signal amplitude of the bubble rupture. AE source characteristic parameters of the bubble rupture are then proposed. The experimental results demonstrate that the two forms of characteristics of the AE signals from corrosion bubble rupture are consistent with theoretical calculation and simulation results. [ABSTRACT FROM AUTHOR]

The fatigue behavior of the 800H weld joint at the temperature of 800 °C was investigated, taking into account the effects of residual stress and microstructure. To model the residual stress in the welded joint, a finite element method was employed and its accuracy was verified using a hole drilling method, which was also used to study the evolution of residual stress during cutting and heating processes. Additionally, the weld region was characterized by measuring the distributions of elements and micro-hardness via energy dispersive X-ray spectroscopy and Vickers hardness tester. Fatigue lives, curves of displacement versus the number of cycles were obtained, and the fracture morphology was analyzed. The results reveal that the calculated residual stress in the weld region agrees well with the experimental results, and the transverse residual stress reduces in magnitude due to cutting and heating. Element distribution and micro-hardness exhibit obvious variations from the base metal to the weld metal. The micro-hardness has a minor effect on residual stress but a significant impact on local stress amplitudes at the weld toe. Furthermore, fatigue fractures primarily occur at the weld toe when the maximum cyclic stress exceeds 200 MPa, while the fracture location varies within the middle weld metal under smaller loads. • The low cycle fatigue behavior of 800H weld joint at high temperature of 800 °C is investigated. • The fatigue life of the weld joint is significantly inferior to that of the base metal. • Variations in properties at the weld joint prominently influence the failure location and fatigue life at the weld toe. • The distinction between the low and high fatigue regimes depends on the failure mechanism rather than the number of cycles. [ABSTRACT FROM AUTHOR]

COF LZU-1 has the characteristics of a porous structure, a large specific surface area, and good chemical stability. In recent decades, extensive research has been conducted on its use as a nanomaterial for drug loading and separation. Here, we report a new corrosion inhibitor encapsulated nanostructure (LZU-1 @BTA). We synthesized LZU-1 via a hydrothermal method and loaded benzotriazole (BTA) corrosion inhibitor into LZU-1. The results show that loaded BTA can achieve effective pH-responsive release under acidic and alkaline conditions. The amino group present in the LZU-1 molecule can cross-link with epoxy resin, and its compatibility allows for good dispersion in epoxy resin without any further modification. The LZU-1 @BTA modified epoxy coating has shown remarkable anti-corrosion properties and excellent self-healing capabilities, which have been evaluated through various techniques such as potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), local electrochemical impedance spectroscopy (LEIS), scanning Kelvin probe (SKP) and salt spray testing. The high-quality dispersion of LZU-1 @BTA in the resin, the high cross-linking density, and the pH-responsive release of BTA in the epoxy resin are some of the key factors that contribute to the excellent anti-corrosion performance of the epoxy resin composite coating. This research has opened up new possibilities for designing anti-corrosion coatings with significantly better corrosion resistance. [Display omitted] • COF LZU-1 was used as a multifunctional gatekeeper for benzotriazole. • LZU-1 @BTA was well-dispersed in epoxy resin without any extra chemical modifications. • LZU-1 @BTA notably improved anticorrosion performance for epoxy coating. • LZU-1 @BTA epoxy-coatings exhibited excellent self-healing performance. [ABSTRACT FROM AUTHOR]

• The morphological characteristics of BSCs on the earthen sites were analyzed. • We obtained the mechanical properties of BSCs on the earthen sites. • The research strategy to determine the effect of plant development in the surface layers of the earthen sites was proposed. Earthen sites are cultural and have rich historical significance. However, most earthen sites have been damaged or even destroyed during historic preservation. To reduce the damage caused by rain, snow erosion, freezing and thawing, these sites should be protected using vascular plant capping technology, which has great research value and application prospects. However, the effect of biological soil crusts (BSCs) on the shallow surfaces of these sites is scarcely understood. Therefore, this study aimed to explore the soil consolidation characteristics of BSCs on the shallow surfaces of earthen sites through laboratory experiments. First, the species, morphology and geometric characteristics of BSCs were studied using observation with a high–resolution digital microscope and analyses of the fractal and topological dimensions of rhizoids. The results showed that the dominant population of BSCs was composed of Didymodon vinealis , and the rhizoid type exhibited herringbone architecture. In addition, the effect of rhizoid anchoring was greater than that of rhizoid wedging. Second, the mechanical properties of the soil consolidation of the rhizoid–soil composite were investigated using tensile strength tests of single rhizoids and shear strength tests of rhizoid–soil composites. It was concluded that moss rhizoids could improve the shear strength of the surface soil. Additionally, the surface roughness of the rhizoids affected their anchorage characteristics. Finally, we discussed the disadvantages of generally classifying plants as "potentially harmful", and emphasized the necessity of constructing a heterogeneous research model highlighting specific environmental factors, plants, and earthen sites. [ABSTRACT FROM AUTHOR]

Loess is a kind of world-recognized problematic soil and, as a consequence, it is a major hazard in geotechnical engineering. This study examines the small to medium strain dynamic properties of Lanzhou intact and recompacted loess through a set of resonant column (RC) tests. The influence of soil structure on the small-strain shear modulus G 0 , the variations of G / G 0, and damping ratio DT(%) with shear strain γ were analyzed and discussed. The test results show that the structure has an important influence on the dynamic properties of dry loess at small and medium strain, whereas, with the increase of moisture, its effect weakens. It is proved that a normalized correlation between G / G 0 and γ/γ 0.7 is practically identical for undisturbed and recompacted loess in Lanzhou, irrespective of soil structure, which may be useful in practical applications. • The small to medium strain dynamic properties of Lanzhou loess with metastable structure were examined. • Structure effect reduces the ductility in dynamic response for Lanzhou loess. • The correlations between G / G 0 and γ/γ 0.70 could be normalized well for Lanzhou loess, irrespective of structure effect. [ABSTRACT FROM AUTHOR]

The mechanism of dissolving acoustic source of Q235B corrosion anode metal is the basis of acoustic emission (AE) source identification and corrosion site evaluation and analysis. In this paper, the local mechanical energy release and the characteristics of radiated elastic wave pulse in the process of metal dissolution are analyzed by using the principles of corrosion dynamics, damage thermodynamic energy conversion, local mechanical energy release and radiation elastic wave pulse characteristics of metal dissolving process, and the theoretical analysis is verified by atomic first numerical method. Combined with AE and electrochemical testing technology, the mechanism of Q235B steel corrosion acoustic source is studied experimentally. The characteristics of the metal dissolved acoustic source are obtained, and the energy conversion value of anode metal in the process of dissolution is extracted. The quantitative characterization formula of the corrosion behavior of the AE is established, which provides a basis for the assessment of the severity of the corrosion state of Q235B steel. • Under the action of electrochemical driving force, the breakage of crystal bonds triggered by the metal atoms leaving the lattice and the jumping mechanical motion of metal atoms in the phase boundary region are accompanied by the radiation of elastic wave pulses, forming the AE source. • The numerical results of the energy released by atoms during corrosion are obtained using atomic first nature numerical calculations. Dissolution of anode metal can be used as the basis for AE detection of Q235B steel corrosion. • A quantitative characterization formula of the corrosion behavior of the AE is established, which provides a basis for the assessment of the severity of the corrosion state of Q235B steel. [ABSTRACT FROM AUTHOR]

Adipose tissue not only affects meat quality and animal productivity, but also participates in inflammation and immunity. Ningxiang pig is famous for their excellent meat quality, disease resistance and tolerance of roughage. It is not yet well known how proteins in adipose tissue is dynamically regulated during the growth of Ningxiang pig. This report studies the proteomic changes in subcutaneous adipose tissue in Ningxiang pigs to gain a better understanding of the molecular mechanism of fat development during the growth period. By TMT-labeled quantitative proteomic analysis of subcutaneous adipose tissue of 9 purebred Ningxiang pigs of different ages, we identified 2533 unique proteins and 716 differentially abundant proteins (DAPs), of which more than half of the DAPs were concentrated in the 90d-210d period. Retrograde endocannabinoid signaling was only significantly enriched in DAPs of N90d vs N30d, Alcoholism and Graft-versus-host disease were only significantly enriched in DAPs of N210d vs N90d. Proteins related to dilated cardiomyopathy was found to be an important pathway in fat development and lipid metabolism. A variety of novel DAPs involved in maintaining mitochondrial function and cell viability, such as NDUFS6, SDHB, COX5A, ATP5D and TNNT1, which play a role in controlling the prediction networks, may indirectly regulate the development and functional maintenance of adipocytes. These age-dependent DAPs discovered in this study may help expand the understanding of the molecular mechanisms of the development, function maintenance and transformation of adipose tissue in Ningxiang pig for developing new strategies for improving meat quality and pig breeding in the future. [Display omitted] • By proteomic analysis of adipose tissue, this study identified 2533 unique proteins and 716 DAPs in the growth period of Ningxing pigs; • DAPs related to dilated cardiomyopathy is distinguished as an important enrichment pathway in pig adipose tissue; • A variety of novel DAPs for maintaining mitochondrial function and cell viability such as NDUFS6, SDHB, COX5A, ATP5D and TNNT1 plays a key role in pig adipose tissue development and energy balance. [ABSTRACT FROM AUTHOR]

To verify the applicability and superiority of the compressible filtered mass density function method in real supersonic mixing flows, a classical experimental subsonic-supersonic spatial mixing layer is numerically investigated. In the present method, a transport equation for the scalar filtered mass density function is solved using the Lagrangian particle solver, while the filtered mass, momentum, and energy equations are fully coupled and solved by the large eddy simulation finite difference solver. First, a parametric study of the mixing model constant controlling the scalar mixing rate is conducted in the two-dimensional case. It is found that the mixing model constant has a significant effect on the root mean square profile of the mixture fraction. The appropriate mixing model constant for this supersonic mixing layer is given by comparing the root mean square results under three different mixing model constants. These results also show that the suitable mixing model constant used in compressible flows is much larger than that used in incompressible flows. Second, three-dimensional simulations are performed to verify the current method. For comparison, a traditional large eddy simulation with the gradient diffusion model is also conducted. The results show that the scalar mixing is better predicted by the filtered mass density function method than the gradient diffusion model. In particular, the mean and root mean square mixture fraction computed by the present method are in excellent agreement with the experimental data whereas the gradient diffusion model overestimates the peak root mean square mixture fraction by about 45%. [ABSTRACT FROM AUTHOR]