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The multi-row stabilizing piles have been applied in the stabilization of large-scale reservoir landslides in recent years. However, the mechanical behavior and deformation characteristics of the multi-row stabilizing piles reinforced reservoir landslides have rarely been investigated. This study takes the Taping landslide, a large-scale reservoir landslide in China, as a prototype. Two centrifuge tests were conducted to study the deformation and failure characteristics of the multi-row stabilizing piles reinforced reservoir landslide with two different row spacings. The result shows that the reservoir water level (RWL) drawdown operation induced the soil movement and high downslope driving force, further causing a significant increase in bending moments at the lower section of the piles, with peaking near the sliding zone; eventually, bending deformation and failure occurred more easily near the sliding zone. The downslope part of the piles can change the mechanical transmission behavior of the multi-row stabilizing piles in reservoir landslides. Small row spacing can enhance the mechanical connection between the rows of piles and raise the overall reinforcement capacity of the piles. The large row spacing weakens the mechanical connection between the rows of piles, and the mechanical states of the pile in different rows are relatively independent. As a result, the piles are easily damaged one by one from the first row to the last row, and the overall reinforcement capacity of the multi-row stabilizing piles is poor.

1. A quantitative approach to species coexistence based on the invasibility criterion has led to an appreciation of coexistence mechanisms in terms of stabilizing and equalizing components, but major challenges are the need to consider general multispecies settings, interactions beyond competition, and multiple scales of space and time. Moreover, two essential concepts, species-level average fitness and scaling factors, have not had clear definitions. 2. A general approach to defining average fitnesses and scaling factors is given, along with the origin of stabilizing mechanisms as deviations from a reference model where no coexistence is possible. Illustrations are general Lotka-Volterra models, models accounting specifically for resource use and natural enemies, and models with temporal fluctuations. 3. Community averages of stabilizing mechanisms reveal overall opportunities for coexistence, and define mechanisms more precisely through their formulae. Average fitnesses adjusted for the presence of coexistence mechanisms provide a better definition of equalizing mechanisms. While these ideas apply to the components of invasion rates, permanence theory and stochastic persistence theory show how invasion rates can be used to demonstrate species coexistence in complex settings. 4. Although species coexistence has often focused on competition, detailed models of the roles of natural enemies provide a new perspective on the opportunities for coexistence in nature. The concept of apparent competition recognizes the essential symmetry between density-dependence from resource depletion and from supporting natural enemies. Natural enemy partitioning is the natural analogue of resource partitioning and has an equivalent role in promoting coexistence. Rather than reinforcing each other, however, the strength of coexistence is often intermediate between that implied by resource partitioning alone and that implied by natural enemy partitioning alone, as elucidated by recent LotkaVolterra theory. 5. Synthesis. Although there are alternative approaches for understanding coexistence in multispecies settings, ideas based on stabilizing and equalizing mechanisms continue to provide new insights. Multiple species and multiple trophic levels are naturally challenging, but the new theories of permanence and stochastic persistence support the critical role of invasion rates in species coexistence, and thus support the understanding to be derived by partitioning invasion rates into average fitness differences and stabilizing components.

The remediation of soil contaminated by heavy metals has long been a concern of academics. This is due to the fact that heavy metals discharged into the environment as a result of natural and anthropogenic activities may have detrimental consequences for human health, the ecological environment, the economy, and society. Metal stabilization has received considerable attention and has shown to be a promising soil remediation option among the several techniques for the remediation of heavy metal-contaminated soils. This review discusses various stabilizing materials, including inorganic materials like clay minerals, phosphorus-containing materials, calcium silicon materials, metals, and metal oxides, as well as organic materials like manure, municipal solid waste, and biochar, for the remediation of heavy metal-contaminated soils. Through diverse remediation processes such as adsorption, complexation, precipitation, and redox reactions, these additives efficiently limit the biological effectiveness of heavy metals in soils. It should also be emphasized that the effectiveness of metal stabilization is influenced by soil pH, organic matter content, amendment type and dosage, heavy metal species and contamination level, and plant variety. Furthermore, a comprehensive overview of the methods for evaluating the effectiveness of heavy metal stabilization based on soil physicochemical properties, heavy metal morphology, and bioactivity has also been provided. At the same time, it is critical to assess the stability and timeliness of the heavy metals' long-term remedial effect. Finally, the priority should be on developing novel, efficient, environmentally friendly, and economically feasible stabilizing agents, as well as establishing a systematic assessment method and criteria for analyzing their long-term effects.

Landslides often occur within the reservoir area behind dams. In China, a common strategy for stabilizing these landslides is to install large piles through the landslide and into the stable ground below. The piles interact with the landslide and constitute a landslide-stabilizing pile system. The deformation of this system under the reservoir operation is more complicated than the deformation of the landslide itself. Understanding the behaviour of this system is very important to the long-term safety of landslides stabilized with piles in reservoirs. The Majiagou landslide, which was selected as a case study, was triggered by the first impoundment of the reservoir behind the Three Gorges dam. A row of anti-slide piles was installed in the landslide in 2007, but monitoring results found these were ineffective at stabilizing the landslide. Subsequently, in 2011, two longer test piles and an integrated monitoring system were installed in the landslide to better understand the failure mode of the landslide and to measure the deformation characteristics of the landslide-stabilizing pile system. Monitoring results show that the Majiagou landslide is a translational landslide with three slip surfaces. The test piles provided local resistance and partially slowed down the sliding mass behind the piles, and the landslide deformation response to external factors decreased for a time. However, after 2 years, the deformation of the landslide-stabilizing pile system reverted to seasonal stepwise cumulative displacements influenced by cycles of reservoir drawdown and rainfall. The monitoring results provide fundamental data for evaluating the long-term performance of anti-slide piles and for assessing long-term stability of the stabilized landslide under the reservoir operation.

The Antarctic ice sheet has been losing mass over past decades through the accelerated flow of its glaciers, conditioned by ocean temperature and bed topography. Glaciers retreating along retrograde slopes (that is, the bed elevation drops in the inland direction) are potentially unstable, while subglacial ridges slow down the glacial retreat. Despite major advances in the mapping of subglacial bed topography, significant sectors of Antarctica remain poorly resolved and critical spatial details are missing. Here we present a novel, high-resolution and physically based description of Antarctic bed topography using mass conservation. Our results reveal previously unknown basal features with major implications for glacier response to climate change. For example, glaciers flowing across the Transantarctic Mountains are protected by broad, stabilizing ridges. Conversely, in the marine basin of Wilkes Land, East Antarctica, we find retrograde slopes along Ninnis and Denman glaciers, with stabilizing slopes beneath Moscow University, Totten and Lambert glacier system, despite corrections in bed elevation of up to 1 km for the latter. This transformative description of bed topography redefines the high- and lower-risk sectors for rapid sea level rise from Antarctica; it will also significantly impact model projections of sea level rise from Antarctica in the coming centuries.A high-resolution update of Antarctic bed topography using mass conservation reveals broad stabilizing ridges for glaciers flowing across the Transantarctic Mountains, and stabilizing slopes beneath Moscow University, Totten and Lambert glacier system.

A healthy soil plant continuum is critical for maintaining agroecosystem functions and ensuring food security, which is the basis of sustainable agricultural development. Diverse soil microorganisms form a complex assembly and play an important role in agroecosystems by regulating nutrient cycling, promoting plant growth, and alleviating biotic and abiotic stresses. Improving microbial coexistence may be an effective and practical solution for the promotion of soil–plant ecosystem health in the face of the impacts of anthropogenic activities and global climate change. Modern coexistence theory is a useful theoretical framework for studying the coexistence of species that are competing for resources. Here, we briefly introduce the basic framework of modern coexistence theory, including the theoretical definitions and mathematical calculations for niche difference and fitness difference, as well as ways to test for these differences empirically. The possible effects of several major biotic and abiotic factors, such as biological interactions, climate change, environmental stress, and fertilization, on microbial niche and fitness differences are discussed. From the perspective of stabilizing and equalizing mechanisms, the potential roles of microbe–microbe interactions and plant–microbe interactions in promoting healthy soil–microbe–plant continuum are presented. We suggest that the use of the coexistence theory framework for the design and construction of microbial communities in agricultural production can provide a solid basis for the biological improvement of agroecosystems.

The green synthesis of nanoparticles (NPs) using living cells is a promising and novelty tool in bionanotechnology. Chemical and physical methods are used to synthesize NPs; however, biological methods are preferred due to its eco-friendly, clean, safe, cost-effective, easy, and effective sources for high productivity and purity. High pressure or temperature is not required for the green synthesis of NPs, and the use of toxic and hazardous substances and the addition of external reducing, stabilizing, or capping agents are avoided. Intra- or extracellular biosynthesis of NPs can be achieved by numerous biological entities including bacteria, fungi, yeast, algae, actinomycetes, and plant extracts. Recently, numerous methods are used to increase the productivity of nanoparticles with variable size, shape, and stability. The different mechanical, optical, magnetic, and chemical properties of NPs have been related to their shape, size, surface charge, and surface area. Detection and characterization of biosynthesized NPs are conducted using different techniques such as UV–vis spectroscopy, FT-IR, TEM, SEM, AFM, DLS, XRD, zeta potential analyses, etc. NPs synthesized by the green approach can be incorporated into different biotechnological fields as antimicrobial, antitumor, and antioxidant agents; as a control for phytopathogens; and as bioremediative factors, and they are also used in the food and textile industries, in smart agriculture, and in wastewater treatment. This review will address biological entities that can be used for the green synthesis of NPs and their prospects for biotechnological applications.

In previous computational fluid dynamics studies of breaking waves, there has been a marked tendency to severely over-estimate turbulence levels, both pre- and post-breaking. This problem is most likely related to the previously described (though not sufficiently well recognized) conditional instability of widely used turbulence models when used to close Reynolds-averaged Navier–Stokes (RANS) equations in regions of nearly potential flow with finite strain, resulting in exponential growth of the turbulent kinetic energy and eddy viscosity. While this problem has been known for nearly 20 years, a suitable and fundamentally sound solution has yet to be developed. In this work it is demonstrated that virtually all commonly used two-equation turbulence closure models are unconditionally, rather than conditionally, unstable in such regions. A new formulation of the $k$ – $\\unicode[STIX]{x1D714}$ closure is developed which elegantly stabilizes the model in nearly potential flow regions, with modifications remaining passive in sheared flow regions, thus solving this long-standing problem. Computed results involving non-breaking waves demonstrate that the new stabilized closure enables nearly constant form wave propagation over long durations, avoiding the exponential growth of the eddy viscosity and inevitable wave decay exhibited by standard closures. Additional applications on breaking waves demonstrate that the new stabilized model avoids the unphysical generation of pre-breaking turbulence which widely plagues existing closures. The new model is demonstrated to be capable of predicting accurate pre- and post-breaking surface elevations, as well as turbulence and undertow velocity profiles, especially during transition from pre-breaking to the outer surf zone. Results in the inner surf zone are similar to standard closures. Similar methods for formally stabilizing other widely used closure models ( $k$ – $\\unicode[STIX]{x1D714}$ and $k$ – $\\unicode[STIX]{x1D700}$ variants) are likewise developed, and it is recommended that these be utilized in future RANS simulations of surface waves. (In the above $k$ is the turbulent kinetic energy density, $\\unicode[STIX]{x1D714}$ is the specific dissipation rate, and $\\unicode[STIX]{x1D700}$ is the dissipation.)

The deformation characteristics of landslides, reinforced by piles having different stiffness, are examined using physical model tests. Taking the Majiagou landslide and its pile system as a real prototype, and using a model test bed with 57-cm-long test piles made of reinforced concrete and polyesteramide to simulate rigid and flexible piles, the displacements of two physical models were monitored during progressive loading to simulate the landslide-stabilizing pile system. The results indicate that (1) the bending moment of the rigid piles showed a reverse S pattern, peaking at the pile head; (2) the bending moment of the flexible piles developed a triangular pattern, peaking at the middle and lower parts of the pile; (3) the relative displacements of the landslide and piles during loading disclose four evolutionary stages, termed initial, coordinated, uncoordinated deformation, and failure; (4) the flexible pile system has a longer coordinated action stage but a shorter uncoordinated stage, than the system constructed with rigid piles. Finally, (5) the rigid piles exert an excellent control of soil deformation upslope of the piles, but it is easier for the landslide to slip over the pile heads. The results provide fundamental data for evaluating the long-term performance of the landslide–pile systems constructed with piles having different rigidity.

Improved quantification of the factors controlling soil organic matter (SOM) stabilization at continental to global scales is needed to inform projections of the largest actively cycling terrestrial carbon pool on Earth, and its response to environmental change. Biogeochemical models rely almost exclusively on clay content to modify rates of SOM turnover and fluxes of climate-active CO₂ to the atmosphere. Emerging conceptual understanding, however, suggests other soil physicochemical properties may predict SOM stabilization better than clay content. We addressed this discrepancy by synthesizing data from over 5,500 soil profiles spanning continental scale environmental gradients. Here, we demonstrate that other physicochemical parameters are much stronger predictors of SOM content, with clay content having relatively little explanatory power. We show that exchangeable calcium strongly predicted SOM content in water-limited, alkaline soils, whereas with increasing moisture availability and acidity, iron- and aluminum-oxyhydroxides emerged as better predictors, demonstrating that the relative importance of SOM stabilization mechanisms scales with climate and acidity. These results highlight the urgent need to modify biogeochemical models to better reflect the role of soil physicochemical properties in SOM cycling.