Slope Region Research Articles

Effect evaluation of grass on shallow stability of unsaturated volcanic soil slope in seasonal cold region

Effect evaluation of grass on shallow stability of unsaturated volcanic soil slope in seasonal cold region

Bridging Aqueous and Organic Electrolytes: Intercalation Mechanism of TiS2 in Sustainable Aqueous Li-Ion Batteries

Aqueous Li-ion batteries (ALiBs) are a promising alternative for large-scale grid storage owing to water's non-flammability, low cost, and ease of purification. However, the narrow electrochemical stability window (ESW) of water (1.23 V) significantly limits the energy density of ALiBs, compared to their non-aqueous counterpart. The use of a highly concentrated electrolyte, such as 21 mol kg-1 (molality, m) of LiTFSI in water, known as the “water-in-salt” (WiS) electrolyte, can widen the water ESW to ~3 V, but its high cost and low environmental sustainability hinder the commercialization of ALiBs. Therefore, we explored the feasibility of cycling layered TiS2 anodes in ALiBs containing dilute electrolytes (i.e. 2 m LiTFSI in water).We obtained a reversible discharge capacity of ca. 80 mAh g-1 at a current density of 50 mA g-1. By employing three-electrode cycling with online electrochemical mass spectrometry, we identified potential-dependent gas evolution from the cell triggered by multiple chemical/electrochemical reactions, such as (1) solvent co-intercalation, (2) partial TiS2 exfoliation, and (3) TiS2-catalyzed water splitting in dilute aqueous electrolytes. We also identified a completely different potential profile of TiS2, when cycled in an aqueous electrolyte, with two distinct redox plateaus at 2.95 V and 2.88 V, followed by a sloping region until 2.3 V (all vs. Li+/Li0). Recall that in classic non-aqueous electrolytes, TiS2 shows a characteristic sloping profile centered at ca. 2.2 V, the peculiar potential profile suggests a different intercalation mechanism of TiS2 in aqueous electrolytes.In this presentation, we will share our latest findings from complementary physicochemical and computational methods to tackle the complex interfacial reactivity between layered anodes and aqueous electrolytes. Operando synchrotron X-ray diffraction data revealed the reversible uptake-release of water molecules between TiS2 layers, which was also confirmed energetically favorable by theoretical modeling. By introducing triethyl phosphate (TEP) as a co-solvent, we successfully tuned the electrochemical intercalation behavior of TiS2 from purely Li-intercalation (as in non-aqueous systems, when using only TEP as the solvent) to hydrated-Li-intercalation (as in concentrated and dilute aqueous electrolytes, when using water/TEP mixtures as the solvent). These findings suggest that solvent co-intercalation can be a promising strategy for ALiBs. The general implication of these results on the electrode-electrolyte interface and interphase in aqueous batteries will be systematically discussed in the talk. Overall, our work provides new perspectives on developing sustainable energy storage technologies. Figure 1

(Invited) Anti-Ambipolar Phototransistors Based on Mixed-Dimensional Heterojunctions

The incapability of modulating the photoresponse of the assembled heterostructure devices has remained a challenge for developing optoelectronics with multi-functionality. In this presentation, we report a gate-tunable and anti-ambipolar phototransistor based on 1D GaAsSb nanowire/2D MoS2 nanoflake mixed-dimensional van der Waals (vdW) heterojunctions. The resulting heterojunction shows asymmetric control over the anti-ambipolar transfer characteristics, possessing the potential to implement electronic functions in logic circuits. Meanwhile, the anti-ambipolar device allows the synchronous adjustment of band slope and depletion regions by gating in both components, thereby giving rise to the gate-tunability of the photoresponse. Coupled with the synergistic effect of the materials in different dimensionality, the hybrid heterojunction can be readily modulated by the external gate to achieve a high-performance photodetector exhibiting a remarkable on/off current ratio of 4×104, fast response of 50 μs and high detectivity of 1.64×1011 Jones. Due to the formation of type-II band alignment and strong interfacial coupling, a prominent photovoltaic response is also explored in the heterojunction. Finally, a visible image sensor based on this hybrid device is demonstrated with excellent imaging capability, suggesting promising applications in future optoelectronic systems.

Elucidating the Lithium-Ion Storage Mechanism in Insertion-Available Hard Carbon with Abundant Closed Porosity: Toward a Practical Material for Batteries

Traditionally, standard lithium-ion batteries (LIBs) are composed of a positive electrode made of metal oxides and a negative electrode made of highly crystallized graphite materials. Graphite materials, with a theoretical capacity of 372 mAh g-1, are chosen as the negative electrode because lithium-ion storage in graphite materials involves lithium-ion intercalation/de-intercalation between graphitic interlayers, a characteristic of faradaic reactions. During galvanostatic charge/discharge (GCD), long plateau regions at low voltages (e.g., 0-0.1 V (vs. Li+/Li)) resulting from multi-staged ion intercalation/de-intercalation are achieved. The low voltage of this intercalation/de-intercalation reaction contributes to enhancing the nominal voltage of LIBs, leading to a higher energy density of the battery.On the other hand, sodium-ion batteries (SIBs) have been extensively researched over the past 10 years as alternative to LIBs to compensate for the gradual scarcity of lithium metal resources. Hard carbon (HC) materials, also known as amorphous non-graphitizable carbons, were introduced to be the negative electrode material for SIBs, since most HCs exhibit very similar electrochemical responses in sodium-ion storage as lithium-ion storage in graphite materials.However, when examining the application of HC materials in lithium-ion storage, it becomes apparent that the development has been significantly limited over the past 20 years. Recent research primarily focuses on biomass-derived HCs and heteroatom-doping on these carbons. This type of HC is abundant in heteroatoms (e.g., N, P, and S) inherited from the intrinsic properties of biomass precursors. While high capacities and excellent rate capabilities are claimed for these biomass-derived HCs, the electrochemical responses of lithium-ion storage in these HCs often exhibit capacitive reactions with a completely sloping region on their GCD curves. Consequently, the miscalculation of capacities can be induced by assessing reversible capacities beyond excessively high voltages (> 1.5 V), even reaching 3 V. The appropriate working voltage window for HCs should be lower than 1.5 V to match with the positive electrodes. Thus, if reevaluating these HCs in a normal voltage window, the obtained reversible capacities are relatively small, due to the deficiency of faradaic reactions signified by the plateau region at low voltages on GCD curves. Additionally, very low initial coulombic efficiencies are often obtained for these highly defected and heteroatom-doped HCs, attributed to the vigorous consumption of electrolyte during the SEI layer formation on their defective sites. As a result, in this work, we introduce a straightforward method to fabricate hard carbon microbeads with tunable microporous structures by carbonizing cross-linked phenolic-formaldehyde (PF) resin spheres, produced through microwave-assisted suspension polymerization. The ultimate goal is to transform HC into a practical battery material for the negative electrode in LIBs, which must possess several abilities similar to graphite (i.e., reversible faradaic reactions with an obvious plateau region at low voltages on GCD curves, low surface area to suppress SEI formation, and good cycling stability). Additionally, the lithium-ion storage mechanism in HCs with varying open/closed porosity is carefully elucidated. By probing the porosity of HC with multiple gas (N2, O2, and CO2) adsorptions, a solid correlation between porous properties and electrochemical responses has been successfully established. As displayed in Figure 1, the results indicate that carbon porosity can change with carbonization temperature. With increasing temperatures, open pores are initially transformed into closed pores, and ultimately, non-porous properties are detected. The electrochemical behaviors in these HCs with distinct porosity differ significantly as demonstrated by GCD curves in Figure 2.It has been found that ultra-micro closed pores (<0.7 nm) are capable of providing confined spaces for lithium ions to be inserted/extracted, characterized as faradaic reactions. Therefore, a plateau region at low voltages can be acquired, leading to additional reversible capacities. Unlike some reported methods, such as holding at a constant voltage, charging/discharging at a very small current density, or overcharging to negative voltage regions, these faradaic reactions are easily unlocked at a current density of 50 mA g-1 in a safe voltage window of 0-0.12 V. As a result, the optimized HC delivers a total reversible capacity of 550 mAh g-1 at 50 mA g-1 in the voltage range of 0-1.5 V. The excellent rate capability and cycling stability of optimized HC are also confirmed. Furthermore, by the post-treatment with hydrogen-assisted reduction, the performance is further enhanced, achieving a reversible capacity of 574 mAh g-1 and an initial coulombic efficiency of 75%. These breakthrough outcomes provide valuable insights for the rational design of hard carbon materials. The optimized hard carbon could be a promising candidate for replacing traditional graphite materials in next-generation LIBs. Figure 1

Evaluating influences of deposition direction and state-dependence on large deformation processes of granular column collapse

This paper examines the impacts of deposition direction and density of granular soils on their large deformation behavior encapsulated by column collapse processes. We combine a critical state-based, anisotropic constitutive model for sand and material point method (MPM). The constitutive model includes state- and fabric-dependent dilatancy and hardening, thus accounting for the effects of density and deposition direction on the mechanical behavior of soils. The MPM model is first validated against experimental results. We then investigate the fundamental connections between local constitutive properties of soils (e.g., friction and dilation) and global column collapse response. Based on these correlations, this work further studies how material density and deposition direction influence collapse behavior, including run-out distance, residual height, and slope angle of the static region. Results indicate that run-out distance is relatively insensitive to initial soil density but can be significantly altered by the deposition direction of soils. Peak run-out distance is observed as the deposition direction is aligned with sliding band formed within the granular column. Moreover, a higher density or a smaller inclination of deposit direction leads to a greater residual height and a steeper slope of the static region. The mechanisms of above effects from soil properties perspectives are discussed.

Dynamically computed characteristic adjustment time scale for Zhang–McFarlane convective parameterization scheme

AbstractCharacteristic adjustment time scale τ is an important parameter in convective parameterization scheme. In this paper, we propose a dynamic calculation formula of τ in the Zhang–McFarlane scheme based on convective available potential energy (CAPE) in order to improve the simulation of precipitation. The performance of using the new formula is tested and evaluated using the Community Atmosphere Model (CAM5) for numerical experiments. The results indicate that the root mean square errors of mean precipitation amount over the Northern Hemisphere eastern equatorial Pacific Ocean, the central Indo-Pacific Warm Pool, the Tibetan Plateau, and northern South America are reduced by 20.15, 16.40, 12.56, and 6.45% in summer, respectively, after a dynamic τ is adopted. The dynamically computed τ improves the Pacific Walker circulation by strengthening the western ascending and eastern descending, and increases the intensity of deep convective precipitation in tropical areas by at least 1 mm/day. Dynamic τ also increases the frequency of large deep convective precipitation in the equatorial Pacific by almost 50%, and decreases the frequency of light deep convective precipitation in many other regions. The dynamic τ has positive effects in the areas with large CAPE and spatiotemporal variability, and also leads to an increase in deep convective precipitation and a significant decrease in large-scale precipitation over high-altitude regions of windward slopes. Therefore, the generation of exaggerated precipitation in the highlands is reduced in the CAM5. Overall, the dynamic calculation of characteristic adjustment time scale can improve precipitation simulation.

Techniques for Conservation Tillage under 15–25% Slope: Soil and Water Conservation, Maize Yield and Yield Components in Basketo Zone, Southern Ethiopia

In steeply sloping regions of Ethiopia, water erosion is the primary cause of soil erosion and land degradation. Poor management of watersheds, inappropriate farming practices, and heavy rainfall all contribute to a continuous process of soil nutrient depletion in mountainous places. A quick loss of soil organic matter, soil deterioration, and a decline in environmental quality could result from the main farmer practice restrictions during plowing. To maintain agricultural productivity and environmental quality, a better farming system is therefore a significant method. This study was conducted in 3 farmer’s fields to investigate the significance of different cultivation practices on soil loss and maize yield under a slope of 19 % during cropping season in 2016 and 2018 at Motkesa Kebele of Basketo Zone, southern Ethiopia. The trial was laid out using a randomized complete block design through four treatments replicated three times on run-off plots. Experimental treatments used in the area were (strip tillage, zero tillage, reduced tillage and farmer practice) with maize planting at a spacing of 25cm by 75cm between plants and between rows respectively. According to the research result zero tillage decreased mean soil loss by 70% -74 % compared with conventional tillage (P &lt; 0.05) and zero tillage has a great potential of controlling soil erosion on steep lands. Additionally, zero tillage was effective in conserving soil moisture increased (36-42%) compared with conventional tillage practices. According to the results of our research data, we advise that in smallholder household farms, the implementation of conservation agriculture has a cost-effective production management method, saves raw materials, increases yield, and reduces manual labor. Further studies are also encouraged in the same agroecology to promote the conservation agriculture system.&#x0D; Keywords: Conservation tillage; maize yield and yield components; soil moisture, soil loss

Endoscopic transsphenoidal resection of a non-functioning ectopic pituitary adenoma located in the clivus: a case report and literature review

We successfully removed a rare ectopic pituitary adenoma from a 64-year-old female patient initially misdiagnosed with a chordoma. The tumor was located in the slope region and posed a challenge due to its rarity and location. Using neuro-navigation and neuro-endoscopic techniques, we performed a transnasal transsphenoidal resection and confirmed postoperatively that the tumor was a non-functional pituitary adenoma. Although the patient experienced temporary cortisol deficiency after surgery, she recovered well. To accurately diagnose ectopic pituitary adenomas of clivus, doctors must carefully evaluate the patient's imaging results and hormone levels. If necessary, nuclear medicine scans can also aid in diagnosis. Endoscopic transnasal-transsphenoidal surgery is the preferred treatment method, and preoperative multimodal imaging evaluation and intraoperative neuro-navigation technology are essential for a successful surgery.

Cumulative ecosystem pressures exerted by demersal fisheries in the Brazilian Meridional Margin: Hotspots and refuges

Demersal fishing operations exert, cumulatively, at least three forms of pressures over the benthic environment: mortality of megafauna (landed and discarded), discards of carrion back to the marine environment (also referred to as Predictable Anthropogenic Food Subsidies - PAFS) and disturbance of the seabed, by contact with bottom gear. This study presents a spatial synthesis of these forms of pressure on the Brazilian Meridional Margin (BMM, SW Atlantic) and their accumulated effect, in contribution to the development of effective space-based fishing management strategies. We analyzed landed catch, discards and effort of 2,125 fishing trips of industrial vessels operating double-rig trawlers, pair trawlers, stern trawlers, bottom longline and gillnets, monitored during 2018 in the main fishing harbors of Southern and Southeastern Brazil. All forms of pressure and the Accumulated Pressure Index (API) were represented spatially in a 20 × 20 nautical mile quads mesh grid. We demonstrated that nearly half of the BMM area was under high pressure. We also delimited fishing pressure hotspots in coastal and shelf areas mostly within the ‘Brazilian Bight’ region, between São Paulo and Santa Catarina states (24–29°S). Conversely, slope regions were found to be less demanded by demersal fishing, with both benthic ecosystems and demersal populations being barely disturbed. These were regarded as the main refuge areas for benthic and benthopelagic megafauna. Double-rig trawling was a major driver of pressure accumulating over half of total number of demersal fishing trips in 2018. Individual double-rig trawling operations also disturbed a seabed area far greater than the areas disturbed by the other fishing gear, and discarded the largest fraction (∼48%) of the produced mortality. Reducing the demersal fishing pressure on the BMM seems to be primarily concerned with abating the intensity of double-rig trawling, and/or diluting their effect through spatial management measures.

Responses of soil and water-related ecosystem services to landscape dynamics in the eastern Afromontane biodiversity Hotspot

The investigation of soil and water-related ecosystem services (ES) and recognizing the spatiotemporal effects of land-use and land cover changes (LULC) are essential for the formulation of conservation strategies. The research employed the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) and the Revised Universal Soil Loss Equation (RUSLE) models for the assessment of ES. The study was carried out in the Kaffa Forest Biosphere Reserve in Ethiopia, which is part of the eastern Afromontane biodiversity hotspots. The aim of this investigation was to examine and map the temporal and spatial fluctuations in sediment retention, soil erosion, and water yield resulting from LULC modifications between 1986 and 2019, and to provide forecasts for the next three decades. According to the RUSLE analysis, the landscapes exhibited estimated soil losses ranging from zero to 1.5 tons ha-1 yr-1 in 1986, 2009, and 2019, respectively. The mean annual sediment exports for the years 1986, 1999, and 2019 were estimated to be 12.6, 9.9-, and 28.7-tons ha−1, respectively. The water yield of the site experienced a notable increase from 9.8 × 109 m3 in 1986 to 19.6 × 10 9 m3 in 1999, and subsequently rose to 39.3 × 109 m3 in 2019, which is considered to be a disadvantageous to the site. The study found a significant positive correlation between water yield and the expansion of settlement area (r = 0.99, P = 0.015) as well as agricultural land (r = 0.99, P = 0.05). It was also found that significant positive correlation found between vegetation dense area such as forest (r < 0.999, P < 0.001) and shrub & bamboo (r = 0.998, P = 0.036) with sediment retention service. The investigation discovered that there existed tradeoffs between the ES of sediment retention and water yield as the slope increased. The results may be attributed to the presence of dense vegetation cover on the elevated slope regions, rendering them unsuitable for agricultural activities, and the concurrent expansion of arable lands in the lower slope areas, which are flat terrains more conducive to cultivation. The transition from land with more vegetation density to land with lower or no vegetation coverage resulted in an increase in soil loss and water yield, while simultaneously decreasing the sediment retention service. Therefore, the findings can be used as a document to guide decision-makers to design soil-water conservation technologies to enhance the ecological integrity of the biosphere reserve.

Long-term and large-scale ecological restoration projects shaped the spatial heterogeneity in new forests

The implementation of long-term ecological restoration projects and policies over the past two decades has played a crucial role in advancing the achievement of Sustainable Development Goal 15. However, the resulting dynamics of new forests remain unclear. In this study, we initially examined the distribution and sources of new forests and subsequently investigated the gross primary productivity (GPP) variations within these forested regions. We discovered that new forests are mainly converted from previously cultivated land, which is primarily due to the Grain for Green Project. The new forests are mainly distributed in mid-low altitude areas and gentle slope regions, indicating that accessible areas are prone to damage but also easy to recover. Over approximately two decades of ecological restoration projects, the GPP of new forests has significantly increased trends and the growth rates of new forests vary significantly in different climatic zones. Moreover, the GPP and growth rates of new forests displayed spatial heterogeneity. Specifically, the GPP in the new forests was highest in the eastern region, followed by the central south region, while the northwest region had the lowest GPP. Meanwhile, the southwest region shows the highest GPP growth rate among new forests, while the northwest region has the slowest growth rate. Furthermore, the average GPP of new forests is lower than stable forests, but new forests in China grow faster (3.735 vs. 2.587), highlighting their substantial carbon potential. These findings indicate that it's crucial to account for variations in stand and forest change rates when modeling forest carbon sequestration potential.

Prediction and Evolution of Carbon Storage of Terrestrial Ecosystems in the Qinling Mountains North Slope Region, China

The Qinling Mountains north slope region constitutes a vital terrestrial ecosystem reserve within China. This study employs land use and land cover (LULC) data spanning from 1990 to 2020. Utilizing methodologies encompassing land use classification, transfer matrix analysis, and the application of the PLUS and InVEST models, this research endeavors to elucidate the spatial-temporal dynamics of land use patterns and associated carbon storage in the region. These analyses are conducted within the context of four prospective scenarios: Natural Development Priority, Arable Land Protection Priority, Ecological Protection Priority, and Urban Development Priority, all projected onto the landscape for 2030. Notably, our findings reveal a consistent decline in carbon storage across all four scenarios for 2030 compared to the baseline year 2020. This stark reality presents substantial challenges to achieving the region’s targets of carbon peaking and eventual carbon neutrality. Furthermore, this paper meticulously delineates six key drivers contributing to this decline in carbon storage. In conclusion, it proffers nine strategic recommendations aimed at augmenting carbon storage, with an overarching objective of establishing a harmonized mechanism capable of balancing urban development, safeguarding cultivated land, fortifying ecological preservation, and enhancing carbon sequestration within the area.

Morphological characteristics, molecular species validation and spatio-temporal distribution of myctophid eggs off the Pacific coast of northeastern Japan

Myctophids in the world's oceans have a huge biomass and act as an important link between secondary producers and upper trophic levels through their extensive diel vertical migrations from the epipelagic to mesopelagic layers. Dominance of myctophid larvae in oceanic ichthyoplankton has been reported from various parts of the major oceans; however, there are few records concerning their eggs. We established species-specific morphological characteristics for identifying myctophid eggs which were then validated by sequence analysis of mitochondrial 12S rRNA and cytochrome b genes using representative subsamples of the morphotypes, and then used the criteria to determine the species composition and spatio-temporal distribution of myctophid eggs. Samples were collected monthly in the epipelagic layer off the Pacific coast of northeastern Japan, resulting in 664 net tows that yielded a total of 10,172 myctophid eggs, defined by a smooth and delicate chorion, segmented yolk, and single oil globule. Subsamples of 160 small, 34 intermediate, and 20 large-sized eggs were sequenced, resulting in their classification as Diaphus theta, Diaphus garmani, and Myctophum asperum, respectively. Mean egg diameter was smallest in D. theta (0.75 mm), intermediate in D. garmani (1.06 mm), and largest in M. asperum (1.31 mm). Eggs of D. theta had a markedly narrower perivitelline space (0.17 mm) than D. garmani and M. asperum (0.49 and 0.71 mm, respectively). Based on morphology, the myctophid eggs were dominated by D. theta (86.0%), followed by D. garmani (12.6%) and M. asperum (1.4%). Abundances of early-stage eggs of D. theta and D. garmani were high during the daytime to dusk but low at night and dawn, indicating that spawning would not be active in the epipelagic layer at night. Spawning can be considered to occur in the mesopelagic layer during the early night, and then the eggs rise to reach the epipelagic layer in the daytime. High abundances of D. theta and D. garmani eggs were observed in the slope region from spring to summer, corresponding with the larval distribution reported for the study area.

Structure Dependent Electrochemical Behaviors of Hard Carbon Anode Materials Derived from Natural Polymer for Next-Generation Sodium Ion Battery.

Hard carbons are one of the most promising anode materials for next-generation sodium-ion batteries due to their high reversible capacity, long cycle life, and low cost. The advantage in terms of price of hard carbons can be further improved by using cheaper resources such as biomass waste as precursors. Lignin is one of the richest natural bio-polymer in the earth which can be obtained from woods. As the lignin has three-dimensional amorphous polymeric structure, it is considered as good precursor for producing carbonaceous materials under proper carbonization processes for energy storage devices. In this study, structural properties of lignin-derived hard carbons such as interlayer spacing, degree of disorder and surface defects are controlled. Specifically, lignin-derived hard carbons were synthesized at 1000 °C, 1250 °C, and 1500 °C, and it was confirmed that the structure gradually changed from a disordered structure to ordered structure through X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Hard carbons exhibit sloping regions at high voltage and plateau region at low voltage during the electrochemical processes for sodium ions. As the heat treatment temperature increases, the contribution to the overall reversible capacity of the sloping region decreases and the contribution of the plateau region increases. This trend confirms that it affects reversible capacity, rate-capability, and cycling stability, meaning that an understanding of structural properties and related electrochemical properties is necessary when developing hard carbon as a negative electrode material for sodium ion batteries.

Distribution of dissolved methane in seawater from the East China Sea to the Ryukyu forearc

Methane is a greenhouse gas, and the East China Sea acts as a source of emissions to the atmosphere. On the other hand, the distribution of methane concentration in the Ryukyu Arc shelf and forearc region has not been clarified. Therefore, we investigated the continental slope and continental shelf areas from the Okinawa Trough to the landward side and the island shelf and forearc areas to the seaward side of the East China Sea. The methane concentration in the Kuroshio Current region was very low, and the methane concentration in the seawater just above the seafloor in the area directly above the hydrothermal systems was exceptionally high. In addition, methane concentration in seawater just above the seafloor where cold seeps and mud volcanoes are known is higher than the background, and higher methane concentrations were found in continental slope area and the island shelf area. The results suggest the existence of previously unreported methane sources such as cold seeps and mud volcanoes in the continental slope region and the island shelf region.

Using the Geoelectric Method to Identify Groundwater Schlumberger Configuration Resistivity in the Gambesi and Sasa Villages, South Ternate District, North Maluku Province

One of the geophysical techniques that may be used to define subsurface lithology is the geoelectric approach. The Schlumberger configuration's resistivity technique is used on the assumption that the distance between the potential electrodes is fixed. In contrast, the distance between the current electrodes progressively varies following the resistivity-to-depth curve and the resistivity table. This study aims to determine the lithology of the soil layer and the lithology of the soil layer that serves as an aquifer based on their respective resistivity values. The acquired data demonstrate the presence of multiple layers, including alluvium, sand, gravel, and andesite, in the subsurface lithology at two sites with a depth of 25 meters and a track length of 50 and 100 meters. Based on the resistivity curve to depth and the findings of data processing at the two data collecting sites, groundwater at location 1 (Gambesi Village) could not be identified in the resistivity table because of the location's hilly terrain and alluvial rock types. However, at location 2 (Sasa Village), groundwater was present at depths of 12.8 meters with thicknesses of 6.24 cm and 0.57 Ωm and at depths of 12.8 meters with thicknesses of 4.91 meters and 297 Ωm, respectively. This region slopes down from this position.

From slope seismic resilience to regional road network resilience: an integrated framework for evaluating the seismic resilience of mountainous road networks

A systematic review was conducted, ranging from the seismic resilience of single slope engineering structures as disaster-bearing bodies to their transformation into disaster-inducing bodies owing to seismic dynamic instability. The resilience of slopes is considered with regard to regional transportation networks, which are most severely threatened by earthquake-induced landslide disasters. For the engineering structure of a single slope as a disaster-bearing body, the stage before the slope engineering loses stability can be considered as the first stage of slope seismic resilience evaluation. This review summarizes the latest progress in seismic resilience evaluation and reinforcement design from the perspective of engineering seismic resilience. In response to the lack of definition for the resilience of existing regional road networks to earthquake-induced landslide impacts during the review, the second stage involves the transformation of the seismic dynamic instability of regional slopes into landslide disasters; resilience is defined as the global system reliability of the regional road network in this study. From the perspective of network reliability, an assessment framework for the resilience of the regional transportation network against seismic landslide disasters is systematically proposed in this study. In accordance with high-dimensional nonlinear network dynamics theory, this paper highlights the future research direction of introducing high-dimensional network dynamics theory into the disaster resilience of regional road networks affected by landslide disasters.

Slope susceptibility map for preventive measures against rainfall-induced slope failure

Rainfall-induced slope failures frequently occurs in many urban areas around the world especially due to the impact of the global warming. Some slope failures result in casualties that have negative impacts on urban sustainability. The slope failures are normally observed near slope surface within the unsaturated zone above the groundwater table. Hence, it is important to incorporate the unsaturated soil mechanics principles in analysing the slope stability during rainfall. This study focuses predominantly on the regional stability analyses of residual soils within the Jurong Formation and Bukit Timah Granite in Singapore. The objective of the study is to develop slope susceptibility map as part of preventive measures against extreme rainfall conditions. The slope susceptibility map was evaluated using 2-D numerical analyses of slopes with historical failure. The recently developed sustainable retaining structure system, GeoBarrier System (GBS) is investigated to understand its suitability as a preventive measure for critical slopes with high risk as identified from the slope susceptibility map. Using Transient Rainfall Infiltration (TRIGRS) and Grid-Based Regional Slope Stability Analysis (Scoops3D), the pore-water pressure distributions and factors of safety (FS) within each zone are determined. The results from slope susceptibility maps and 2-D numerical analyses are consistent. Moreover, the incorporation of GeoBarrier System on the critical slope is demonstrated to be an effective slope stabilization measure based on the numerical simulations of two-dimensional analyses.

Rationally Designing Closed Pore Structure by Carbon Dots to Evoke Sodium Storage Sites of Hard Carbon in Low‐Potential Region

AbstractHard carbon (HC) is widely regarded as the most promising anode material for sodium‐ion batteries (SIBs). For improving the sodium storage capacity of HC anode, current research primarily focuses on the high‐voltage slope region. Actually, increasing the storage capability in the low‐voltage plateau region is more important for enhancing the energy density of full cells. Therefore, in this study, HC anode with rich closed pore structure is designed and constructed with the help of carbon dots (CDs), and it is demonstrated that the presence of closed pore structure can provide more sodium storage sites in the plateau region, resulting in an obvious increase of sodium storage capacity. Moreover, the pore‐filling and intercalation mechanism for sodium storage in plateau region is revealed by in situ Raman spectroscopy and ex situ transmission electron microscopy (TEM). It is worth noting that the increase in capacity induced by closed pore‐filling is not accompanied by a decrease in initial coulombic efficiency (ICE), due to the fact that the introduction of closed pores does not increase the contact area between electrode and electrolyte. This work presents novel concepts for the structural design of HC and provides valuable insights into the effective utilization of plateau region in SIBs.

Arrested pneumatization of the sphenoid sinus: imaging characteristics

Objective: To explore and analyze the imaging features of arrested pneumatization of the sphenoid sinus, so as to provide reference for identifying sphenoid lesions. Methods: From May 2018 to September 2019, a retrospective analysis was conducted on 350 patients (183 males and 167 females, aged between 18 and 73 years) who had been completed the sinus CT examination in the outpatient department of Beijing Chaoyang Hospital Affiliated to Capital Medical University. Their imaging data were collected and the CT/MRI characteristics of the sphenoid body were observed. SPSS 26.0 software was used for statistical analysis. Results: The rate of arrested pneumatization of the sphenoid sinus was 2.0% (7/350), which occurred in the pteroid process, the slope region, and the sphenoid sinus body, respectively. CT showed a nondilated mixed-density lesion (7/7) in the pneumatizable sphenoid body. Within these regions, both fat and soft tissue density (7/7) were present. Internal curve calcification was observed in part of the region (3/7). The skull base canal structure was not affected (7/7). MRI showed a clear non-dilated lesion with an adipose signal, and none of the lesions showed medulla dilation or cortical destruction. Conclusions: Arrested pneumatization of the sphenoid sinus is a normal anatomic variation. When non-dilated lesions with clear bony boundaries and internal fatty components are encountered in the vaporizable region of the sphenoid sinus, the possibility of arrested pneumatization of the sphenoid sinus should be considered.