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• A new rigid-flexible composite recyclable supporting structure is proposed. • Numerical calculation and full-scale test are developed for the new supporting system. • Mutual validation of full-scale test and finite element result is carried out. • The full-scale test shows that the new supporting system is stable. The underground ecological granary has the advantages of low temperature, heat insulation, safety, and mechanization operation of moving grain in and out of the granary. It is the most suitable environmentally friendly warehouse for long-term grain storage at present. Traditional underground granary supporting structures mostly use cement materials and present disadvantages including long periods of construction, difficulties in repairing cracks and leakages, and difficulties in demolition. Based on a steel skeleton supporting structure and flexible waterproof polymers, this paper proposed a new rigid-flexible composite recyclable supporting structure for underground storage granaries. Through the use of ABAQUS software, this paper established a three-dimensional finite element numerical model for excavation of the new supporting structure; analyzed stresses and deformations of the steel pile, middle beam, and steel plate and ground settlement at different excavation steps; and checked the stability of the new supporting structure. Additionally, considering a certain ecological storage granary in Zhongmou County of Henan Province, this paper developed a full-scale test for the new supporting structure. By monitoring the stresses of the supporting structure and ground settlement during excavation, it was concluded that the field monitoring results basically matched the results from numerical simulation. The new supporting structure has the advantages of good stability, quick construction, recyclable usage, low cost, and broad application prospects. [ABSTRACT FROM AUTHOR]

Abstract Recent evidence revealed that circular RNAs (circRNAs) are key regulators for tumorigenesis. However, their roles in papillary thyroid cancer (PTC) is not fully understood. In the current work, the differentially expressed circRNAs between PTC tissues and adjacent noncancerous tissue samples were screened by circRNA microarray. We further selected the highest expressed circRNA (circ_0025033) in tumorous tissues for the study. qRT-PCR was used to measure the level of circ_0025033 in PTC tissue samples and cell lines. Gain/loss of function assays were carried out to determine the effect of circ_0025033 on cell viability, clone-forming, apoptosis, migration and invasion. Dual-luciferase reporter assays were conducted to investigate the mechanisms of circ_0025033 in PTC. The data showed that circ_0025033 aggravated cell proliferation, migration and invasion and inhibited cell apoptosis. Additionally, circ_0025033 could directly sponge miR-1231 and miR-1304 in PTC cells. Furthermore, the oncogenic role of circ_0025033 is dependent on its suppression of miR-1231 and miR-1304. Collectively, this work uncovers a novel signal of circ_0025033/miR-1231/miR-1304 involved in PTC initiation and progression. Highlights • The expression of circ_0025033 is elevated in PTC tissues and cell lines. • Circ_0025033 promotes PTC cells development and progression. • Circ_0025033 sponges miR-1231 and miR-1304. • The oncogenic role of circ_0025033 is partly attributed to its suppression of miR-1231 and miR-1304. [ABSTRACT FROM AUTHOR]

The stable hydrogen and oxygen isotope technique is typically used to explore plant water uptake; however, the accuracy of the technique has been challenged by hydrogen isotope offsets between plant xylem water and its potential source water. In this study, the soil hydrogen and oxygen isotope waterline was used to correct the hydrogen isotope offsets for Salix psammophila and Caragana korshinskii , two typical shrub species on the Chinese Loess Plateau. Five different types of isotopic data [(i) δ18O, (ii) δ2H, (iii) combination δ18O with δ2H, (iv) corrected δ2H and (v) combination δ18O with corrected δ2H] were separately used to determine the water-use patterns of the two shrubs. The δ2H offset values of S. psammophila and C. korshinskii did not show significant temporal variation among the sampling months (May, July and September) but showed notable differences between the two shrubs (−0.4 ± 0.5‰ in S. psammophila vs −4.3 ± 0.9‰ in C. korshinskii). The obtained water absorption proportion (WAP) of S. psammophila in the different soil layers (0–20, 20–60 and 60–200 cm) did not differ significantly among the five different input data types. However, compared with the input data types (iii) and (v), the data types (i), (ii) and (iv) overestimated the WAP of C. korshinskii in the 0–20 cm soil layer and underestimated that in the 60–200 cm layer. The data type (iii) overestimated the WAP of C. korshinskii in 0–20 cm soil layer (25.9 ± 0.8%) in July in comparison with the WAP calculated based on data type (v) (19.1 ± 1.1%). The combination of δ18O and corrected δ2H, i.e. data type (v), was identified as the best data type to determine the water use patterns of C. korshinskii due to the strong correlation between the calculated WAP and soil water content and soil sand content. In general, S. psammophila mainly used (57.9–62.1%) shallow soil water (0–60 cm), whereas C. korshinskii mainly absorbed (52.7–63.5%) deep soil water (60–200 cm). We confirm that the hydrogen isotope offsets can cause significant errors in determining plant water uptake of C. korshinskii , and provide valuable insights for accurately quantifying plant water uptake in the presence of hydrogen isotope offsets between xylem and source water. This study is significant for facilitating the application of the stable hydrogen and oxygen isotope technique worldwide, and for revealing the response mechanism of shrub key ecohydrological and physiological processes to the drought environment in similar climate regions. [ABSTRACT FROM AUTHOR]

A novel electrochemical sensor was presented for the determination of 4-nonyl-phenol (NP), which was constructed by molecularly imprinted polymer (MIP), nitrogen-doped graphene nanoribbons (NGNRs) and ionic liquid (IL). The NGNRs were prepared by unzipping multiwalled carbon nanotubes, followed by hydrothermal treatment with ammonium–NaOH solution. The MIP was prepared by electropolymerization at the NGNRs-IL composite film modified electrode, using NP as template, o-phenylenediamine and o-toluidine as copolymerization monomers. The resulting sensor MIP/NGNRs-IL/GCE showed good performance. Under the optimized conditions, the peak current was linear to NP concentration in the range from 0.04 to 6 μM. The sensitivity and detection limit were 3.4 μA/μM and 8 nM (S/N = 3), respectively. The electrochemical sensor was applied to the determination of NP in real samples and satisfactory results were obtained. [ABSTRACT FROM AUTHOR]

Abstract: MTH1745, from thermophilic archaea Methanothermobacter thermoautotrophicum, is a protein disulfide isomerase-like protein (PDIL) with a chaperone function and disulfide isomerase activity. Mercuric cations have a high affinity for sulfhydryl groups and consequently inhibit plant growth. Disulfide compounds (e.g., copper–zinc superoxide dismutase, Cu/Zn SOD) and sulfhydryl compounds (e.g., glutathione, phytochelatins, and metallothioneins) play important roles in mercury (Hg) response. To study the relationship between Hg detoxification and PDILs, we overexpressed MTH1745 in Oryza sativa L. cv. Nipponbare by Agrobacterium-mediated transformation. The transgenic rice seedlings displayed Hg tolerance with obvious phenotypes and more effective photosynthesis compared to wild-type plants. Furthermore, lower levels of superoxide anion radicals, hydrogen peroxide, and malondialdehyde were observed in leaves or roots of transgenic plants. Antioxidant enzyme activities of superoxide dismutase and peroxidase were notably higher in transgenic seedlings under different concentrations of mercuric chloride. Moreover, increased content of non-protein thiols, reduced glutathione (GSH), and GSH/GSSG (GSSG, oxidized glutathione) ratio were also observed in the detoxification of Hg. These results indicated that heterologous expression of a PDIL from extremophiles in rice could protect the synthesis, increase stability of proteins, and enhance Hg tolerance in rice. [Copyright &y& Elsevier]

orption ability for heavy metals varies among plant species. This study is to evaluate the absorption characteristics of different plant species and planting patterns for heavy metals. Five plant species (tomato, maize, greengrocery, cabbage, and Japan clover herb) were cultivated in monoculture and in intercropping in soil contaminated with heavy metals (Cd, Pb, Cr, Cu, and Fe), to determine the absorption status. Tomato absorbs greater amounts of heavy metals (especially Cd). Furthermore, accumulation of heavy metals increased when tomato was intercropped with other plant species. Maize accumulates greater amounts of Cr, Cu, and Fe. The heavy metal concentrations were reduced when maize was intercropped. Cd and Pb accumulated more in roots of Japan Clover Herb, and the levels of all five heavy metals decreased when intercropped. Tomato intercropping is a feasible method for phytoremediation of heavy metal-contaminated soil, and maize intercropping is feasible for obtaining safe harvest which can be eaten securely. [ABSTRACT FROM AUTHOR]

The present study employs the k-epsilon turbulence model to investigate the influence of stable stratification with different Richardson numbers (Rib) on flow patterns and pollutant dispersion near tall buildings. The results show that thermal stratification significantly affects the flow pattern around buildings. As Rib increases, the leeward stagnation point gradually shifts upward toward the top of the building, while the recirculation region on the top of the building moves downward, and the length of the recirculation region on the windward side initially increases and then decreases. The vortex position gradually moves above the building. The region with high TKE/uH2 is primarily concentrated on the top of the building and within the downwind recirculation area. As Rib increases, the TKE/uH2 decreases in the top and wake regions of the building. With increasing Rib, the ground-level pollutant concentration first increases and then decreases, the height of the downwind plume gradually reduces, while the maximum concentration in the plume rises. [ABSTRACT FROM AUTHOR]

The diffusion of chemical grouts in porous media is important for soil reinforcement and stabilization. Slurry diffusion radius and pressure change are important parameters to measure the grouting effect. Using flower tube grouting to make Newtonian fluid slurries diffuse in a column–hemispherical shape is common in engineering, but its diffusion law is still unclear. In terms of the diffusion process, the grout adjacent to the grouting hole first spherically diffuses; with the continuous grouting, it will gradually intersect and overlap and then enter the second diffusion stage, at which the grout will continue to diffuse in a spheroidicity and the slurry in the middle does not spread out vertically anymore. If the stages during grouting are not considered, there will be some errors between the slurry diffusion and the actual situation. Meanwhile, in the traditional study of slurry diffusion law, the tortuous effect of the pore channels and viscosity time denaturation of grout is not considered, resulting in an obvious deviation between the calculated grouting diffusion diameter and the actual value. Therefore, based on the fractal theory, a two-stage column–hemispherical diffusion model of Newtonian fluid was derived considering the tortuosity of porous media and the time-dependent viscosity behavior of slurry. The influences of grouting flow rate, slurry viscosity and pore tortuosity on grouting pressure and diffusion radius under constant flow grouting mode were analyzed. The results show that the grouting flow rate had a positive effect on both of the diffusion radius and the grouting pressure, while the slurry viscosity and porosity tortuosity had a positive effect on the grouting pressure but a negative effect on the diffusion radius. Under the same condition, compared with the traditional column–hemispherical grouting diffusion model, the column–hemispherical grouting diffusion model with two-stage diffusion considering porosity zigzag had a larger diffusion radius and required a lower grouting pressure. The numerical simulation and model test also proved that the calculated diffusion radius and injection pressure from the theoretical model developed in this study were closer to the measured results, with an error of less than 10% in the diffusion radius and less than 20% in the grouting pressure. Therefore, the model may provide a certain reference for grouting design, construction and theoretical research. [ABSTRACT FROM AUTHOR]

Pipe jacking shaft is an important part of pipe jacking construction, its support structure can support the soil around the pipe jacking shaft to prevent soil destabilization and collapse and ensure construction safety. Most of the existing support structures of pipe jacking shafts are made of cement materials, which have the advantages of high bearing capacity, good integrity and easy access to materials, but also have inherent disadvantages such as high construction cost, long construction period, difficulty in dismantling, and inability to reuse demolition waste, which are not conducive to the sustainable construction. Based on the concept of sustainable construction, this paper proposes a reusable support structure for pipe jacking shafts, which is made of H-shape steel, steel plate and water stop by welding or bolting assembly, easy to install and disassemble, and can be recycled and reused. In order to verify the bearing performance of the new support structure and evaluate the risk of destabilization during excavation, finite element numerical simulation and full-scale test were carried out, and gives the safety design parameters of new supporting structures by using orthogonal tests. The results show that the finite element numerical simulation results are basically consistent with the full-scale test results, further proving that the numerical simulation results can be used to guide the design and construction feasibility of the support structure during the excavation of the pipe jacking shaft. The construction machinery has a great effect on the safety and stability of the support structure during excavation, and the distance between the construction machinery and the pipe jacking shaft should be reasonably controlled to avoid the risk of structural instability. The results of the sensitivity analysis show that the steel type of the support structure and the spacing of the piles are the two most important factors, which play a key role in the safety and stability of the support structure and should be highly noted in the design and calculation process. [ABSTRACT FROM AUTHOR]

• Proposed a novel assembly pipe jacking shaft support structure. • Performed pipe jacking practical engineering field test. • Established finite element model for pipe jacking construction. • Mechanical response of the support structure was analyzed. • Sensitivity analysis was performed on the design parameters of the support structure. Pipe jacking construction is a commonly employed trenchless technique for laying underground pipes in urban areas. However, the conventional support structure for pipe jacking shafts poses challenges, including difficulty in reserving pipe jacking holes, susceptibility to tilting, low bearing capacity, and the potential for failure during construction. Taking the 5# pipe jacking shaft of the pipe jacking construction for diverting the Yellow River through the river at Niukouyu in Zhengzhou City as the research background, investigates the soil settle deformation around the working shaft and the mechanical response law of the supporting structure during the short-distance, long-distance and second long-distance pipe jacking construction by combining the practical engineering field test and finite element numerical simulation, and carries out a sensitivity analysis on the main design parameters affecting the stability of the supporting structure through orthogonal test. The findings reveal that during the second pipe jacking construction, stress and deformation of the supporting structure are higher than those observed in the first pipe jacking. Notably, support piles and waist beams at the entrance of the pipe jacking experience greater force, and the back and side walls undergo increased force and deformation in the later stages of pipe jacking, and support pile spacing is the main control factor affecting the mechanical performance of the novel support structure. The study concludes that monitoring and protection measures should be reinforced, particularly in areas prone to failure and damage during construction. The insights gained from this research can serve as a reference for designing, optimizing, and safely monitoring novel assembled pipe jacking shaft support structures. [ABSTRACT FROM AUTHOR]

Check dam lands (DLs) and hillslope lands (SLs) are two typical landscape units in the semi-arid Loess Plateau of China (CLP). Knowledge of the water resource distribution and water use characteristics of plant species used for revegetation in SL and DL has profound implications for understanding plant–water relations and guiding revegetation strategies in water-limited ecosystems. To assess the spatiotemporal characteristics of water resource and investigate water use strategies of two widely used species for revegetation (i.e., Medicago sativa and Caragana korshinskii) in the SL and DL, numerous types of water samples (including rain-, soil-, plant-, and groundwater) were collected from a watershed in the semi-arid CLP for analysis. The oxygen and hydrogen stable isotopic ratios (δ18O and δD) of the water samples were estimated for three consecutive hydrological years (2018−2020). The soil water storage in the unsaturated zone of 0–600 cm in the DL (mean 1008 mm) was estimated to be 64% higher than that in the SL (mean 613 mm). Below 600 cm, soil was saturated with water (i.e. groundwater) in the DL and remained unsaturated in the SL. The Bayesian mixing model was applied to the stable isotopic ratios of H and O, which revealed significant differences (p < 0.05) in the proportional contributions of water resources between the two revegetated species. Although M. sativa (mean 76% for SL and 61% for DL) and C. korshinskii (mean 72% for SL and 47% for DL) relied on water from the upper 100-cm soil layer during the observation period, C. korshinskii generally utilised more water from the deep soil layer (>100 cm) than M. sativa. Furthermore, the mean water uptake fractions of C. korshinskii in both the SL and DL for the deep soil layers and groundwater significantly increased with decreasing annual rainfall, whereas this was not observed for M. sativa , suggesting that the environmental adaptability of C. korshinskii may be more ecologically plastic than that of M. sativa. Additionally, the contribution of groundwater (>600 cm) to root water uptake in M. sativa (mean, 21%) and C. korshinskii (mean, 28%) was comparable in the DL, indicating the importance of groundwater in combating possible water stress for revegetated plants. These results indicate that natural and engineering measure-induced water resource distributions result in different plant water-use characteristics and responses to variations in precipitation. Therefore, engineering measures and species are essential factors in ecological restoration management for enhancing the effectiveness of vegetation restoration strategies. ● Check dam land (DL) has more water storage than hillslope land (SL). ● Caragana korshinskii can use more water from deep soil (>100 cm) than Medicago sativa. ● Shallow groundwater plays a critical role for plant water uptake in DL. ● C. korshinskii may be more ecologically plastic than M. sativa. [ABSTRACT FROM AUTHOR]

• Water use pattern was investigated for Caragana korshinskii on sunny and shady slopes. • Caragana korshinskii seasonally switched its water sources from different soil layers. • Caragana korshinskii on sunny slope used shallower soil water than that on shady slope. • Root distribution and soil moisture affect water use pattern of Caragana korshinskii. Flexible water use patterns are of great importance for the survival of vegetation in dryland regions. Our study aimed to investigate the influences of season and slope aspect on the water use patterns of Caragana korshinskii on typical shady and sunny slopes on the Loess Plateau in China. We collected xylem water, soil water from the 0–200 cm soil layers, and precipitation in May, July, September and November 2018 and measured their hydrogen (δD) and oxygen (δ18O) isotope compositions. The root distribution of C. korshinskii in the 0–200 cm soil layer on both slopes was also investigated. The 0–20, 20–80, and 80–200 cm soil layers were identified as three potential water sources for C. korshinskii , and their proportional contributions to the plant water supply were calculated using a linear mixed model. The results showed that C. korshinskii on the sunny slope absorbed 89.3% of their water from the 0–20 cm soil layer in May but mainly utilized water from the 0–20 and 20–80 cm soil layers in both July and September, and the total contribution percentages of these layers were 84.5% and 89.2%, respectively. However, C. korshinskii on the shady slope extracted water evenly from all three soil layers in May. Thereafter, the plants absorbed water from the 20–80 and 80–200 cm soil layers in both July and September, and the total contribution percentages of these layers were 96.0% and 91.8%, respectively. In November, C. korshinskii absorbed 84.8% and 78.0% of their water from the 80–200 cm soil layer on the shady and sunny slopes, respectively. The generally shallower soil water use of C. korshinskii on the sunny slope than on the shady slope may be due to the larger fine-root (d < 2 mm) length density in the 0–80 cm soil layer on the sunny slope (1.12 ± 0.28 mm/cm3) than on the shady slope (0.57 ± 0.16 mm/mm3) (P < 0.05). This study indicates that C. korshinskii on both shady and sunny slopes seasonally switched their water sources from different soil water layers during the growing season. However, due to their reliance on soil water at the 0–20 cm depth, which is supplied by unstable rainfall, C. korshinskii on sunny slopes may be more vulnerable to future climatic warming and drying on the Loess Plateau. Our findings provide valuable information related to optimal water management in the afforested shrublands in this region. [ABSTRACT FROM AUTHOR]

• Strength degradation mechanism of concrete in dry-wet environments was investigated. • Strength of concrete in dry-wet cyclic environments was evaluated using NDT methods. • The effect of dry-wet cycle time on the rebound value of concrete was studied. • The effect of dry-wet cycle time on the acoustic velocity of concrete was studied. • The porosity of concrete in a dry-wet cycle environment was tested with CT. To develop an effective non-destructive testing (NDT) method to assess the strength of concrete in dry and wet cyclic environments, concrete compressive strengths were evaluated of six different mix ratios in this study using ultrasonic method, rebound method and quasi-static compression tests indoors. Firstly, the results of concrete indoor quasi-static compressive strength tests were compared with the NDT results and the optimum NDT methods applicable to different concrete strength classes were determined. Subsequently, an in-situ NDT evaluation of concrete gates exposed to dry and wet environments for a long-term period was carried out based on the results of the laboratory indoor tests, and the degradation mechanism of concrete strength under dry and wet cyclic conditions was revealed by rebound method testing, borehole coring, and industrial computerized tomography (CT) scanning. The results show that the concrete strength obtained by the ultrasonic rebound method is closer to the actual value when the initial strength of concrete is less than 30 MPa; When the initial strength of concrete is between 30 and 40 MPa, the concrete strength obtained by the rebound method is closer to the actual value; When the initial strength of concrete is greater than 40 MPa, the concrete strength obtained by the rebound and ultrasonic rebound methods differ greatly from the quasi-static compressive strength. In addition, the compressive strength of concrete increases and then decreases with the number of dry and wet cycles increases. In the early stage of the dry and wet cycle, the main reason for the increase of the concrete strength is that the filling of the pores by the hydration products reduces the porosity of the concrete; As the number of dry and wet cycles increases, the hydration products absorb water to expand and lose water to shrinkage, which leads to microcracks, and this is the main reason for the decrease of the concrete strength in the late stage of the dry and wet cycle. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Continuous record of paleoclimate and paleoenvironment from Qionghai Lake has been presented. • Multiple proxies have been applied for paleoclimate interpretation. • Paleoclimate shifts generally follow the changes of North Hemisphere Solar Insolation. • Variations of Mo content probably can be used as a potential proxy to reveal paleoclimate changes. Abstract Multi-proxy records of paleoclimate changes spanning the past 30 cal ka BP were obtained from Qionghai Lake sediment core, Sichuan Province, southwest China, where southwest summer monsoon prevails. The core was studied for molecular compositions of n -alkanes, stable carbon isotope ratios (δ13C) of organic matter (OM), total organic carbon (TOC), total nitrogen (TN) and trace elements. Evidence from n -alkanes, cross chart of C/N-δ13C values and trace elements indicated the organic matter derived from a mixed source composed of autochthonous aquatic organisms and allochthonous terrestrial plants, and the sediments mainly deposited in reducing conditions, which is in favor of preservation and accumulation of OM. Variations of n -alkanes biomarker proxies, δ13C of organic matter and Mo concentrations reflected three stages of paleoclimate evolution during the past 30 cal ka BP: a relatively warm and humid climate between 29.1 and 22.9 cal ka BP, corresponding to a strong southwest summer monsoon; climate shifted towards cold and dry condition during the period of 22.9–15.7 cal ka BP, in response to the reduced insolation and weakened southwest summer monsoon; temperature and humidity gradually increased in the Holocene with fluctuations, broadly track the strengthening trend of southwest summer monsoon. Our findings further confirm that variations in solar activity may primarily affect the strength of southwest summer monsoon, resulting in the shifts of paleoclimate conditions. Further studies are needed to better constrain the detailed forcing drivers which may amplify the intensity of southwest summer monsoon particularly in the Holocene period. [ABSTRACT FROM AUTHOR]

Flexible water use patterns are of great importance for planted trees if they are to acclimate to more uncertain future conditions in water-limited regions. This study aims to understand seasonal water use patterns of rainfed jujube trees in stands of various ages. A two-year experiment was conducted at four plantations of different ages (4-, 8-, 15-, and 22-years-old), in which the stable isotope technique was combined with three analytical methods. Soil moisture in the shallow (0–20 cm), middle (20–60 cm), and deep (60–200 cm) layers served as potential water sources for the jujube trees. The results showed that the 4-year-old trees mainly used soil moisture from shallow and middle layers. The 8-year-old trees shifted flexibly their water source between the three layers. However, the 15- and 22-year-old trees often ignored moisture in shallow layers and primarily used water from subsurface layers, obtaining more soil moisture from the middle layer in periods with more rainfall while more soil moisture from the deep layer when the precipitation was low. Compared with the 4- and 8-year-old trees, the two low precipitation periods during the study period clearly resulted in more water use from deep layers for the 15- and 22-year-old trees. Overall, older jujube trees were more dependent on soil water from deeper layers compared to younger trees, resulting in extensive use of soil water from deeper layers which was difficult to be replenished by precipitation. This indicates that older trees are more vulnerable to future prolonged and extremely low precipitation, and measures are needed to improve water status, especially for deeper layers under older trees. [ABSTRACT FROM AUTHOR]

• Proposed a polyurethane anchor bolts. • Considering the influence of polyurethane density, anchorage length and borehole diameter, in-situ pull-out test was carried out. • The expression describing the pull-out load–displacement relationship of polyurethane bolts in silt layer was established. • The analytical model of axial force and bonding stress of polyurethane bolts in silt layer are derived. The bonding performance between the anchor anchorage body and soil is an important index to evaluate the anchoring performance of anchor bolts. In this work, the vertical polyurethane grouting anchor bolt is taken as the research object, and the bonding performance between polyurethane anchorage body and silty soil was studied by 13 sets of field pull-out tests, and the distribution law of the axial force and the bonding stress of the polyurethane anchor bolts along the anchoring depth, as well as the influence of the diameter (D = 60 mm, 75 mm, 90 mm, 100 mm, 120 mm), density (ρ = 0.2 g/cm3, 0.3 g/cm3, 0.4 g/cm3, 0.5 g/cm3, 0.6 g/cm3) and length (L = 2.0 m, 2.5 m, 3.0 m, 4.0 m, 5.0 m) of the polyurethane anchorage body on the bonding strength between the polyurethane anchorage body and silty soil were analyzed in detail, and finally the load transfer equation of polyurethane anchorage body under vertical pull-out load was obtained by theoretical derivation. The results show that the error between the calculated results of the load transfer equation and the experimental results is less than 12%, which further indicates that the load transfer equation derived in this paper can reasonably describe the distribution of axial force and bonding stress along the anchorage depth of the polyurethane anchor bolts. The axial force of polyurethane anchor bolt is the largest at the top of the bolt body, and decreases along the anchoring depth, and the axial force at the bottom is far less than that at the top. Polyurethane anchor bolt has significant bonding stress concentration phenomenon, with the increase of load the peak bonding stress and bonding stress distribution area increases, and shifts to the bottom of the anchorage body. The borehole diameter, anchorage body density, and anchorage body length all have important effects on the bonding strength: the bonding strength increases with the increase of anchorage body density, and the increase is more obvious in the case of small density, and the increase of bonding strength becomes smaller after the density exceeds 0.4 g/cm3, the bonding strength decreases with the increase of anchorage body length and borehole diameter. [ABSTRACT FROM AUTHOR]

[Display omitted] • Seasonal water use patterns differed among different aged S. psammophila. • 6-yr S. psammophila mainly absorbed 0–120 cm soil water across seasons. • 12- and 18-yr S. psammophila shifted water sources between dry and rainy seasons. • Severe soil desiccation and root die-back occurred in 18-yr S. psammophila stand. • Changes in root distribution and SWC affected age-related water use patterns. Understanding the water use pattern of artificially restored vegetation is important to provide reasonable water management strategies. However, the characteristics, controls and differences of water sources of planted Salix psammophila at different developmental stages remain poorly understood. In this study, the hydrogen and oxygen isotope compositions of xylem water, soil water, and rainwater were measured and coupled with the MixSIAR model to investigate the variations and controls of water use patterns of different aged S. psammophila in a semi-arid region in northeastern Mu Us Sandy Land. Results showed that >60% of water used by 6-yr S. psammophila derived from 0 to 120 cm soil layer throughout the growing season due to the relatively shallow roots (0–100 cm). In contrast, water sources used by 12- and 18-yr S. psammophila differed markedly between the dry and rainy seasons, which were attributed to the developed dimorphic root systems and seasonal changes in soil water profile. In the dry season, 12- and 18-yr S. psammophila extracted 71.93% and 68.91% of water from 120 to 300 cm and 40–200 cm soil layer, respectively; in the rainy season, however, they both shifted main water sources to 0–120 cm soil layer (65.09% and 56.14%). The severe soil desiccation and dead roots observed in the 18-yr stand decreased the ability of old S. psammophila to extract water from the deep soil layer (200–300 cm) in the dry season. Thus, changes in the vertical distribution of roots and soil water contents controlled the seasonal water use pattern of different aged S. psammophila. Our study demonstrates that the age-dependent water use pattern of S. psammophila should be considered to implement the corresponding management measures in future afforestation plans to avoid overuse of water and maintain sustainable vegetation restoration in the water-limited desert regions. [ABSTRACT FROM AUTHOR]

• Transpiration of P. sylvestris increased with increasing tree age. • Seasonal water use pattern differed markedly among different aged P. sylvestris. • Older P. sylvestris increased absorption of deep soil water and groundwater. • Aggravated soil drying and faster groundwater decline occurred in the oldest stand. Understanding the water use pattern and transpiration rate of revegetation species is crucial for efficient water management and sustainable vegetation restoration. Mongolian pine (P. sylvestris) plantation has been implemented for decades in desert regions of northwest China, achieving significant improvements in combating soil erosion and desertification. However, the characteristics of water use pattern and transpiration of P. sylvestris at different ages remain poorly understood. We investigated seasonal variations in water uptake pattern and transpiration of different-aged P. sylvestris (4-, 10-, and 18-yr) based on stable isotope and sap flow measurements over two growing seasons. The canopy transpiration of P. sylvestris and its discrepancy between the dry and rainy season increased with increasing stand age. The 4-yr P. sylvestris extracted water mainly from shallow soil layer (0–120 cm) across the growing season (63.21–69.40%). In contrast, the older P. sylvestris (10- and 18-yr) displayed a greater degree of ecological plasticity as they shifted water uptake to deeper soils and groundwater in times of drought. In the rainy season, 10-, and 18-yr P. sylvestris extracted water predominantly from shallow soil layer (68.62%) and shallow plus middle soil layers (0–200 cm) (66.04%), respectively; in the dry season, however, they both shifted main water sources to the middle plus deep soil layers (120–300 cm) (61.29% and 63.45%). The older P. sylvestris also increased absorption of groundwater in the dry season, leading to more severe soil desiccation and faster groundwater decline. The changes in water use patterns of P. sylvestris were related to differences in root distribution and biomass, seasonal variations of plant transpiration, and changes in soil water condition. As a consequence, the variations and controls of age-dependent plant water uptake and transpiration should be considered to implement the corresponding management measures in future reforestation activities to achieve sustainable development goals. [Display omitted] [ABSTRACT FROM AUTHOR]

• The HS sequence recovered 165 erosion and hydrological events over CE 1811–1996. • The total tendency of erosion extent in the HS region was decreased since the 1810s. • The threshold value of hydrological events at this area was greater than 40 mm. • Interannual monsoon storm by ENSO was the primary factor in soil erosion on the CLP. • Human activities (wars, policies) also impact on soil erosion fluxes on the CLP. Evaluating the effects of soil and water conservation on the Chinese Loess Plateau (CLP) during the past 60 years depends mainly on understanding the historical processes of soil erosion fluxes and their mechanism. However, little was known about the historical variation in soil erosion and its driving factors due to the lack of few ideal geological carriers on the CLP. A representative Heshui (HS) landslide-dammed reservoir that formed 200 years ago was drilled with a 31.39 m length sediment sequence. The HS sequence was composed of 165 deposition couplets with 56 annual freeze–thaw layers based on the elemental distributions by X-ray fluorescence core scanners. Mean couplet and annual specific sediment yields (CSSY and ASSY) were 1.44 × 104 t/km2 and 1.28 × 104 t/km2/yr, respectively. The HS sequence was deposited over CE 1811–1996, which was dated by multi-methods crossing among 137Cs activities, annual freeze–thaw layers, CSSY, recent rainfall records, and historical flood index grades. Besides, the threshold value of hydrological events that generated sediments in the HS reservoir was greater than 40 mm. As a result, there were eight periods of high ASSY between CE 1811 and 1996, although the total tendency of the ASSY was decreased, especially under the management of soil and water since the 1960s on the CLP. Interannual change of monsoon storms under El Niño-Southern Oscillation events was the primary factor affecting the variations in ASSY and storms in the HS region. Besides, human activities, such as policies and wars, also had significant influences on the historical soil erosion processes in this region. These results not only shed light on the historical changes in soil erosion fluxes and corresponding hydrological events during the past 200 years in the plateau-gully area of the CLP, but the active mechanisms under the different driving factors were also better understood. [ABSTRACT FROM AUTHOR]