Deposition Conditions Research Articles

Depositional architecture and evolution of Quaternary submarine canyon-fan system in the Baiyun Sag of the Pearl River Mouth Basin, northern South China Sea

Submarine canyons in the shelf margin usually serve as essential conduits for delivering sediments to slopes and basins and coevally develop turbidite reservoirs within deep-water fan systems. To understand the control of the evolution of the canyon-fan system, we focused on Quaternary deep-water depositional systems imaged in 3D seismic reflection data covering the lower reaches of the canyons and the base of the slope in the Baiyun Sag, on the northern margin of the South China Sea. By analyzing seismic facies tied to seismic attribute maps and time-thickness variations, three main seismic units were interpreted and described with markedly different geomorphologies and facies assemblages. Variations in the depositional architecture of the fan system recorded changes in sediment conditions during the Quaternary. The evolution of the Quaternary canyon-fan system can be summarized in three stages. Stage 1 is characterized by fan complexes with backstepping and stratigraphic onlapping against the erosional base, indicating a reduction in sediment supply due to rapid transgression during the Early Pleistocene. During Stage 2, the sediment supply decreased to its lowest rate, producing elongate-shaped turbidite complexes and a high proportion of hemipelagic deposits. In contrast, stage 3 was expressed by canyon-fan systems with downlapping stratigraphy resulting from the enhancement of sediment input during shelf margin/slope progradational intervals. The Quaternary canyon-fan system evolution was controlled not only by the rapid transgression but also by the efficiency of the sediment transfer mechanisms. Although higher rate of sediment supply occurred during stage 1, the dominant canyon-direct fed systems at this stage had highly efficient sediment transfer mechanisms, generating thicker and larger canyon-fan systems compared to stage 3. During stage 3, the progradation-direct-fed system became the primary sediment transport pattern causing sediment to mostly accumulate on the slope and reduce sediment delivery to the basin floor. Our results indicate that the distribution of gas hydrate accumulation is strongly associated with the depositional pattern of turbidites within the Lower Pleistocene succession.

Analysis of deformation and failure of sediment particle-surrounding rock structure of salt cavern gas storage under the coupled action of temperature and pressure

When gas is injected or produced in the gas storage of salt cavern, the different effects of thermal stress, gas pressure, sediment particles and brine pressure on the cavity wall of salt cavern may cause large deformation and damage in the surrounding rock, which threatens the safe and stable operation of the gas storage of salt cavern. Therefore, based on FLAC3D-PFC3D coupling method, a numerical model of salt cavern gas storage with sediment particles in consideration of temperature was constructed, and the influence of injection-production time effect, sediment particle size and initial porosity on the deformation and failure of sediment-surrounding rock structure is studied. The results show that the tensile contact force chain of sediment is sensitive to the particle size of sediment, but insensitive to the initial porosity of sediment and injection-production conditions; during gas production, the larger the particle size and initial porosity of sediment particles, the greater the vertical displacement of shallow sediment particles, and the opposite results are obtained during gas injection. With the progress of gas production and gas injection, the absolute value of vertical displacement of the roof of the salt cavern increases gradually, and the plastic failure range of surrounding rock expands; for gas production process, the larger the particle size and initial porosity of sediment, the smaller the algebraic value of vertical displacement of surrounding rock at the top of cavity and the smaller the plastic failure range of surrounding rock. For the gas injection process, the larger the particle size and initial porosity of the sediment, the larger the algebraic value of the vertical displacement of the surrounding rock at the top of the cavity and the larger the plastic failure range of the surrounding rock. The results can provide reference for the reasonable setting of injection-production operation parameters of salt cavern gas storage and ensure the safe and stable operation of underground salt cavern gas storage (USCGS).

Rapid Prototyping for Accelerated Establishment of Film Processing‐Performance Relationships in Silicon Phthalocyanine OFETs

AbstractUnderstanding the complex relationships underlying the performance of organic electronic devices, such as organic field‐effect transistors (OFETs), requires researchers to navigate a multi‐dimensional parameter space that includes material design, solution formulation, fabrication parameters, and device geometry. Herein, a recently developed materials acceleration platform is demonstrated, named the RoboMapper, to perform direct on‐chip fabrication of OFETs by ultrasonic meniscus printing using silicon phthalocyanine (SiPc) derivatives as the semiconductor. OFETs using bis(tri‐n‐butylsilyl oxide) SiPc ((3BS)2‐SiPc) exhibited the best device performance characterized by the highest electron field‐effect mobility (µe). Through optical microscopy and grazing‐incidence wide‐angle X‐ray scattering (GIWAXS), the favorable performance of (3BS)2‐SiPc is attributed to the specific film morphology and molecular packing achieved with optimal print conditions. Investigating the impact of deposition parameters reveals the crucial role of solvent evaporation rate and print speed in achieving high‐quality film formation. Overall, optimal fabrication conditions for (3BS)2‐SiPc devices include slow print speeds and fast evaporating solutions achieved by using a mixture of co‐solvents and an elevated substrate temperature. The results of this work reveal distinct relationships between deposition conditions, film properties, and device performance for each SiPc derivative and emphasize the necessity of high throughput experimentation to comprehensively understand process‐performance relationships in organic semiconductors.

Insights into the K–Pg extinction aftermath: The Danish Cerithium Limestone Member

The Cretaceous–Palaeogene (K–Pg) mass extinction about 66 Ma ago was one of Earth's largest mass extinction events. The demise of calcifiers, among others, influenced biogeochemical cycles and changed the conditions for carbonate deposition in the global ocean. This study addresses the sedimentology and carbonate microfacies of the Cerithium Limestone Member of the Rødvig Formation within the renowned Stevns Klint succession in Denmark. The limestone was deposited in the earliest Danian Stage, immediately after the K–Pg mass extinction. It is a pale yellow, partly cemented unit with a dense network of Thalassinoides burrows and numerous flint nodules. Studies of the thin sections revealed that the Cerithium Limestone Member is more variable than expected from its overall homogeneous appearance at the macroscopic scale. The thin sections and scanning electron microscope (SEM) images showed that the highly bioturbated limestone consists of four principal microfacies: a mudstone, a wackestone and two different packstones. The 30 to 120-cm thick Cerithium Limestone Member fills depressions between low-amplitude mounds in the Maastrichtian chalk. The lowermost part constitutes a thin layer of a bryozoan-rich packstone, probably reworked from the crests of the Maastrichtian mounds. The successive part of the member is dominated by wacke stone with mainly foraminifera (planktic and benthic), molluscs and echinoderm debris, and in some areas an abundance of peloids. The foraminifera- and mollusc rich packstone appears in lenses. The mudstone contains few foraminifera and is linked to burrows and syn-sedimentary fractures. SEM observations revealed that the Cerithium Limestone Member corresponds to a dispersed micrite, with small calcite crystals ~1–4 µm in size. The general shape of these calcite crystals suggests precipitation from cyanobacterial activity and, thus, a microbial genesis for the micrite of the Cerithium Limestone Member.

ESTIMATION OF THE CLEANING TIME OF THE BOTTOM-HOLE ZONE OF WELLS IN CONDITIONS OF UNCERTAINTY

The aim of the work is to analyze changes in the maximum optimal flow rates of wells operating various groups of productive formations of the Volga-Ural oil and gas province under conditions of uncertainty of geological and field data. The relevance of the work is due to the deterioration of the structure of residual oil reserves and the need for the most efficient extraction of liquid hydrocarbon resources, optimization of design methods for various treatments of the bottomhole formation zone. Using geological and statistical modeling systems, the timing of cleaning the bottomhole zones of wells from drilling products was determined at the time they reached their maximum optimal flow rate in conditions of deposits confined to various stratigraphic horizons, and appropriate models of changes in productivity coefficients were constructed. The factors influencing the recovery time of the real properties of the reservoir at the point of opening it by the well, which, among other things, determines the profitability of the process of selecting residual oil reserves, have been established. Among them, the most relevant and necessary for the implementation of an integrated approach to computer support procedures for the development of oil fields are the productivity of wells, fracturing of formations, their proximity to a particular tectonic-stratigraphic complex, geological, physical and physico-chemical properties of formations and their saturating fluids. For the deposits of the Famensk tier of deposits of the Volga-Ural oil and gas province, a multiple decrease in the time of removal of reaction products after hydrochloric acid exposure at objects with low fracturing has been established. At the same time, additional processing of the bottomhole formation zone within areas with high drilling density does not affect the total cleaning time of the bottomhole zone of wells. Stimulation of the removal of drilling mud filtrate and additional products of formation reactions by injection of hydrochloric acid compositions under certain conditions can lead to a decrease in the actual productivity of wells due to the introduction of less developed and dead-end cracks into the drainage process. The existence of the specifics of the procedure for cleaning the bottomhole formation zone depending on the geological and physical parameters of productive formations is substantiated and various patterns of changes in the productivity coefficient depending on the time of wells reaching the maximum optimal flow rate are revealed. The results obtained make it possible to make informed technological decisions to improve the efficiency of oil production, including in conditions of uncertainty, which may be caused by the lack of the necessary volume of hydrodynamic studies of wells.

Electrophoretic deposition of carbon-ionomer layers on proton conducting membranes.

Synthetic and natural carbons are widely used as carrier for electrodes in electrochemical applications. They need to have a controlled morphology in order to facilitate mass and charge transport, so the process of film formation is of uttermost importance. Here we show, how carbons (after proper preconditioning) can be codeposited with an ionomer by electrophoretic deposition, a method that does allow full control of deposition conditions during the process. In view of potential applications, we focus on the direct deposition on proton-conducting membranes. Ionomers and membranes applied are based on established per-fluorinated polyethylene with SO3H-terminated side chains (PFSA). Conditions for reproducible deposition are reported in terms of optimal charge on the carbon particles, field strength in the deposition cell and necessary deposition times for a given film thickness. Additionally, a horizontal cell arrangement is suggested to avoid gravitational effects.

The Mechanism of Aluminum Deposition and Dendrite Growth on a Copper Substrate in Anode-Free Aluminum Batteries.

Given the critical demand for batteries with a high energy density and the global scarcity of lithium, anode-free aluminum batteries (AFABs) have attracted significant attention. AFABs utilize collectors instead of traditional anode metal foils, eliminating the need for anode materials and significantly enhancing the energy density of the batteries. However, the proliferation of aluminum dendrites might cause safety risks and reduce Coulombic efficiency, possibly impeding commercialization. This study employs molecular dynamics (MD) simulations to explore the deposition mechanisms of aluminum (Al) on copper (Cu) collectors and the dynamics of aluminum dendrite growth under nonhomogeneous deposition conditions. The results indicate that the surface properties of the Cu substrate significantly affect aluminum deposition, leading to more homogeneous and amorphous deposition on Cu(110) surfaces. However, the FCC structure of Al atoms on the Cu(111) surfaces exhibited the largest number. Strategically increasing the temperature and pressure can effectively prevent the formation of aluminum dendrites. The results are helpful for enhancing the battery cycle stability and the application of novel AFABs.

Microscopic examination of rf-cavity-quality niobium films through local nonlinear microwave response

The performance of superconducting radio-frequency (SRF) cavities is sometimes limited by local defects. To investigate the rf properties of these local defects, especially those that nucleate rf magnetic vortices, a near-field magnetic microwave microscope is employed. Local third-harmonic response (P3f) and its temperature dependence and rf power dependence are measured for one Nb/Cu film grown by direct current magnetron sputtering (DCMS) and six Nb/Cu films grown by high-power impulse magnetron sputtering (HiPIMS) with systematic variation of deposition conditions. Five out of the six HiPIMS Nb/Cu films show a strong third-harmonic response that is likely coming from rf vortex nucleation due to a low-Tc surface defect with a transition temperature between 6.3 and 6.8 K, suggesting that this defect is a generic feature of air-exposed HiPIMS Nb/Cu films. A phenomenological model of surface-defect grain boundaries hosting a low-Tc impurity phase is introduced and studied with time-dependent Ginzburg-Landau (TDGL) simulations of probe-sample interaction to better understand the measured third-harmonic response. The simulation results show that the third-harmonic response of rf vortex nucleation caused by surface defects exhibits the same general features as the data, including peaks in third-harmonic response with temperature, and their shift and broadening with higher microwave amplitude. We find that the parameters of the phenomenological model (the density of surface defects that nucleate rf vortices and the depth an rf vortex travels through these surface defects) vary systematically with film deposition conditions. From the point of view of these two properties, the Nb/Cu film that is most effective at reducing the nucleation of rf vortices associated with surface defects can be identified. Published by the American Physical Society 2024

Ichnological record in gateways and other high-energy deepwater environments: a palaeo- and neoichnological approach

The evolution of gateways determines variations in palaeoenvironmental (ecological and depositional) conditions affecting tracemaker communities, and hence biogenic structures. With respect to palaeogateways, bottom currents and associated deposits (i.e. contourites) may be approached through trace-fossil studies. Ichnological analysis – individual ichnotaxa and changes in ichnofacies – of Late Miocene contourites and associated facies from the Rifian Corridor palaeogateway (Morocco) reveals a major impact of food supply, flow velocity, seafloor heterogeneity and hydrodynamic energy. The fact that Eocene to middle Miocene deep-marine deposits, mainly contourites, from the nearby Indian palaeogateway (Cyprus) show ichnofacies replacement is evidence of increased bottom-current flow velocity associated with sea-level variations. Moreover, ichnofabric changes reflect pelagic, gravitational and bottom-current processes that simultaneously influence sedimentation. Changes in the trace-fossil composition of both areas, and in the shape of burrows, reflect intermittent bottom-current processes that governed contourite deposition. Neoichnological studies complement and validate the trace-fossil record of high-energy deep-sea environments that can occur in palaeogateways. Modern traces ( lebensspuren ) observed on the seafloor show variable features (e.g. diversity, density, morphology) depending on the type of disturbance that high-energy conditions exert on the trace-making benthic fauna. Parameters such as substrate consistency, nutrient availability/distribution and the duration and intensity of energetic events play a major role in determining lebensspuren features. We conclude that an integrative palaeo- and neoichnological approach is a powerful tool when used to improve our knowledge of benthic ecosystems in high-energy deep-sea environments such as gateways.

Machine Learning-Enhanced Fabrication of Three-Dimensional Co-Pt Microstructures via Localized Electrochemical Deposition

This paper presents a novel method for fabricating three-dimensional (3D) microstructures of cobalt–platinum (Co-Pt) permanent magnets using a localized electrochemical deposition (LECD) technique. The method involves the use of an electrolyte and a micro-nozzle to control the deposition process. However, traditional methods face significant challenges in controlling the thickness and uniformity of deposition layers, particularly in the manufacturing of magnetic materials. To address these challenges, this paper proposes a method that integrates machine learning algorithms to optimize the electrochemical deposition parameters, achieving a Co:Pt atomic ratio of 50:50. This optimized ratio is crucial for enhancing the material’s magnetic properties. The Co-Pt microstructures fabricated exhibit high coercivity and remanence magnetization comparable to those of bulk Co-Pt magnets. Our machine learning framework provides a robust approach for optimizing complex material synthesis processes, enhancing control over deposition conditions, and achieving superior material properties. This method opens up new possibilities for the fabrication of 3D microstructures with complex shapes and structures, which could be useful in a variety of applications, including micro-electromechanical systems (MEMSs), micro-robots, and data storage devices.

Corrigendum to: Thermodynamic analysis of ethanol steam reforming using Gibbs energy minimization method: A detailed study of the conditions of carbon deposition [International Journal of Hydrogen Energy 34 (2009) 4321–4330]

Corrigendum to: Thermodynamic analysis of ethanol steam reforming using Gibbs energy minimization method: A detailed study of the conditions of carbon deposition [International Journal of Hydrogen Energy 34 (2009) 4321–4330]

Carbon, iron and sulfur records of lacustrine paleo-environments during the middle Eocene in eastern China

It is widely recognized that anoxic conditions facilitate the preservation of organic carbon in marine sediments. However, the specific geological factors that lead to the development of such conditions in paleo-lakes are less well understood. Owing to their smaller size, paleolakes could experience more frequent and stronger changes in geochemical conditions than oceans. Such changes, such as volcanism, hydrothermal fluids, or ocean transgressions, can also strongly affect the lacustrine organic carbon burial thereby complicating sediment diagenesis record. Here, we used total organic carbon content (TOC), organic carbon isotope (δ13Corg), iron speciation, and pyrite sulfur isotope (δ34Spy) data to establish relationships between organic carbon preservation and anoxic conditions in fine-grained sediments from the middle Eocene lacustrine depositional environments from the Shahejie Formation of the Jiyang Depression, Bohai Bay Basin, eastern China. The results reveal TOC between 1 % and 10 %, highly-reactive iron to total iron ratios >0.38, and most TOC to total sulfur ratios exceeding 2. These data indicate that the organic-rich shales of the Shahejie Formation were formed as a result of high primary productivity during the warm and humid middle Eocene period, coupled with the efficient preservation of organic matter in anoxic bottom waters. Negative δ13Corg and δ34Spy excursions recorded in the Shahejie Formation indicate water column conditions to have been influenced by transient volcanic eruptions. Positive δ13Corg and negative δ34Spy excursions may have been caused by hydrothermal fluids input whereas δ34Spy values approaching 20 ‰ suggest frequent marine transgressions. In particular, despite potential inputs of S into the paleolake by volcanism, hydrothermal fluids, or marine transgressions, bacterial sulfate reduction efficiently depleted the sulfate pool to have created ferruginous geochemistry water conditions for the effective preservation of organic carbon in sediments. Our results establish a direct link between lacustrine shale geochemical signatures and geological phenomena that impact its sedimentation.

Effect of particle materials on deposition behavior and microstructural features of films prepared via vacuum kinetic spraying

Vacuum kinetic spraying (VKS) is a particle deposition process by which various materials can be deposited as films, even at room temperature. In this study, Al2O3 (ceramic, completely brittle), Fe-based bulk metallic glass (BMG, brittle with some plastic deformability), and Ag (metal, completely ductile) were used as powder materials, and the effects of the particle materials on the deposition behavior and microstructural features of the film were investigated. Deposition tests were performed under identical experimental conditions, and the microstructural features were comprehensively analyzed. The deposition behavior and film microstructure of the three materials were completely different. The Al2O3 film formed at the lowest deposition rate was extremely dense and comprised nanocrystals with a relatively low surface roughness, indicating fragmentation-dominant deposition. The deposition rate of Ag was between those of the other two materials, and the film consisted of relatively dense large grains with nanopores and a smooth surface, resulting from plasticity-dominant deposition. The deposition rate of BMG was considerably high, and the resulting film consisted of a porous structure with relatively large fragments and an extremely rough film surface. These features of BMG were attributed to the insufficient fragmentation or plastic deformation of the particles. Consequently, even under identical deposition conditions, the deposition rate and behavior and the resulting film microstructure vary depending on the particle materials. Therefore, the microstructural features of the film must be examined before selecting powder materials and fabricating films through process optimization for each material.

Optimization of LPCVD Deposition Conditions of Silicon-Rich Silicon Nitride to Obtain Suitable Optical Properties for Photoluminescent Coating

Silicon nitride is a commonly used material for ceramic applications and in the fabrication processes of integrated circuits (ICs). It has also increased in interest from the scientific community for use as a functional coating due to its physical, mechanical, electrical, and optoelectronic properties. In particular, silicon-rich silicon nitride (SRSN) has been considered in the photovoltaic industry as a down-conversion film for solar cells. In this work, SRSN films have been obtained by the Low-Pressure Chemical Vapor Deposition (LPCVD) technique at low to moderate deposition temperatures with a variation in the precursor gas pressure ratio. The SRSN films showed a wide photoluminescence (PL) in the visible region (without a high-deposition temperature or annealing process) and suitable optical properties (refractive index and absorption in the UV) to be used as photoluminescent coating on silicon solar cells. The absence of high-deposition temperatures could preserve the original structure of silicon solar cells, once the SRSN layer was applied. In addition, control of the reactive gas pressure ratio and deposition temperature showed an influence on the refractive index, the surface roughness, and the PL emission.

Assessment of recent lake sediment conditions in the conterminous U.S.

This study provides the largest sediment quality assessment of lakes in the conterminous United States (U.S.). A variety of lakes (n = 1005) were selected based on the randomized, probabilistic sampling design of the broader 2017 National Lakes Assessment study. Surficial sediment samples (0–5 cm) were collected at one representative site (generally the deepest point) for each lake (n = 969). The samples were analyzed for 16 metal(loid)s, 25 polycyclic aromatic hydrocarbons (PAHs), 53 polychlorinated biphenyl (PCB) congeners, 27 legacy pesticides and metabolites, total organic carbon, and grain size. Metal(loid)s and PAHs were widely distributed due to natural and potential anthropogenic sources, with regional variations observed for lakes in the nine ecoregions encompassing the U.S. Most sites did not have detectable PCB congeners or legacy pesticides. An integrative chemical index of mean probable effect concentration quotients, composed of seven metal(loid)s and ƩPAH13, was used to assess sediment quality for the estimated population of 224,916 lakes in the conterminous U.S. Nationally, 26.5 % (CI of 20–33 %) of lakes were in good condition (corresponding to predicted low incidences of toxicity to benthic organisms), 69.3 % (CI of 63–76 %) of lakes were in fair condition, and 1.8 % (CI of 0.6–3 %) of lakes were in poor condition (corresponding to predicted high incidences of sediment toxicity). Unweighted metal(loid) and ƩPAH13 concentrations were compared to lake, watershed, and land use data. Deeper lakes were significantly more contaminated (or naturally enriched) with As, Cd, Cu, Pb, Hg, Zn, and ƩPAH13 than shallow lakes. Lakes at lower elevation were also associated with more contamination (or natural enrichment) of As, Cr, Pb, Hg, Ni, Zn, and ƩPAH13 than higher elevation lakes. Greater contamination was associated with watersheds containing larger percentages of developed land. This study demonstrates an approach which can be used by others to assess sediment quality in their jurisdictions.

Key Sputtering Parameters for Precursor In2O3 Films to Achieve High Carrier Mobility.

Owing to their extremely high carrier mobility (μ) of >100 cm2/(V s) and suitable low carrier concentrations, transparent conducting films of solid-phase crystallized H-doped In2O3 (spc-IO:H) exhibit high conductivity with high optical transparency over a broad frequency range. These properties can be attributed to solid-phase crystallization of the amorphous precursor film. Therefore, the development of high-quality spc-IO:H films requires the deposition conditions of the precursor films to be optimized. This study systematically investigates the effects of three key sputtering parameters, namely, water vapor partial pressure (PH2O), radio frequency magnetron sputtering power (PRF), and flow ratio of O2 to total sputter gas (fO2) on the crystallographic texture evolution of spc-IO:H films during solid-phase crystallization. In addition, the carrier transport in the resulting films is examined. PH2O, PRF, and fO2 are found to be indispensable for producing high-mobility (>100 cm2/(V s)) spc-IO:H films. Furthermore, it is found that introducing a small amount of PH2O during deposition, a lower PRF, and a suitable fO2 facilitates the formation of precursor films having a lower crystallite density. Moreover, after annealing at a temperature of 200 °C, the IO:H precursor films with a lower crystallite density are found to have larger crystal grains. However, the μ values of the postannealed IO:H films are mainly correlated with the stoichiometric deviation.

Innovative geological–geotechnical zoning framework for urban planning: Wuhan’s experience

Traditional methods for understanding geological conditions, such as borehole drilling and on-site tests, are often costly and impractical for extensive urban areas like Wuhan’s Main Urban Area. This study introduces an innovative geological–geotechnical zoning framework that utilizes limited data to overcome these challenges, essential for urban planning, underground space development, and construction design. We began by dividing the study area into four primary geological units based on geomorphological characteristics, using a novel method validated at four metro stations. Our approach incorporated data from 1544 geological boreholes to compile a comprehensive database, from which six typical stratigraphic profiles for each unit were identified. These profiles facilitated the estimation of potential layers and their corresponding geotechnical parameters, and the identification of subsurface hazards. The study resulted in a detailed engineering geological zoning divided into nine secondary units. Our analysis not only demonstrates the effectiveness of the proposed criteria for geomorphological units in achieving more accurate and quantifiable outcomes but also shows the framework’s suitability for regions with complex sedimentary conditions. The resultant engineering geological zoning enhances understanding of geological risks, providing a foundation for safer and more sustainable urban development.

The constraints of sedimentary environment on the evolution of bauxite reservoir characteristics within the benxi formation in the Linxing area, Ordos Basin, China

AbstractThe breakthrough of bauxite natural gas in the Taiyuan Formation in the Longdong area of the Ordos Basin makes bauxite natural gas gradually become a new exploration direction. However, the complex sedimentary conditions and diverse developmental strata of the Linxing region present difficulties for the exploration of bauxite gas. In this research, samples of bauxite cores from significant drilling sections in the Linxing area were obtained for comprehensive geochemical, mineralogical, and pore structure analysis. This study investigates the impact of sedimentary environments on the physical properties of bauxite reservoirs within the Benxi Formation, focusing on lithofacies categorization, mineral composition, and pore structure. This study established a lithofacies categorization system that iron minerals, aluminum minerals + titanium minerals, clay minerals as three end‐member components. The study identified four lithofacies types: pure bauxite, clayey bauxite, mixed bauxite, and bauxite mudstone. According to geochemical analysis, the bauxite rock in the study area is deposited in a semi‐enclosed bay with terrestrial freshwater input. The physical properties of bauxite reservoir in the study area are relatively poor, among which the physical properties of bauxite reservoir are the best. Authigenic minerals like pyrite are often filled in dissolution pores. The constraint of sedimentary environment on bauxite reservoir is mainly manifested as the influence on the formation of diaspore mineral framework, and its acidity and alkalinity are very important for the formation of diaspore. Hence, diaspore commonly forms in the shallow lake environments characterized by pure bauxite rock, exhibiting favorable reservoir conditions. This research examines the impact of mineral composition on bauxite reservoirs through the lens of lithofacies and sedimentary environments. The variations in bauxite rock reservoirs across distinct sedimentary environments have been elucidated. It provides a new guidance for the exploration of natural gas in Benxi Formation bauxite in Ordos Basin.

Development of the Ge-MDST instrument structure with an induced p-type channel

The conditions for the growth of n-type Ge conduction layers by the HW CVD method with the parameters required to create a Ge-TIR transistor with an induced p-type channel are determined. The conditions of deposition by electron beam deposition and subsequent annealing of layers of a high-k dielectric ZrO2:Y2O3 are optimized, allowing to achieve a leakage current of 5 × 10–6 A/cm2. For the developed instrument structure, some parameters of the Ge-TIR transistor were calculated, such as the channel length, the maximum voltage between the drain and the source, and the breakdown voltage.

Assessment of Water Status, Bottom Sediments, Macrophytes in the Light of Index Analysis and Geochemical Parameters of Selected Dam Reservoirs of Kielce Upland (Poland)

Concentrations of trace elements such as Cr, Zn, Cd, Co, Mn, Cu, Ni, Pb, and Fe were investigated in water, bottom sediments, and macrophytes (Phragmites australis and Typha latifolia L.) collected from the Borków, Wilków, and Rejów water reservoirs in the Kielce Upland (Poland). The main objective of this study was to investigate the condition of water, bottom sediments, and macrophytes in selected three sedimentary basins of the Kielce Upland and to identify natural and anthropogenic factors influencing this condition. The secondary objectives were (i) to determine the contents of trace metals in water, bottom sediments, and macrophytes, (ii) to assess the quality of abiotic and biotic elements of the ecosystem based on selected criteria, (iii) to compare reservoirs in terms of pollution, and (iv) to determine the ability of macrophytes to be used as a bioindicator of water/sediment pollution. Field tests were conducted in 2021. The trace metals in water were determined by ETAAS (Cr, Cd, Mn, Cu, Ni, Pb) and FAAS (Zn), and spectrophotometry method (Fe). The trace metals in sediments and macrophytes, including Cr, Zn, Cd, Co, Mn, Cu, Ni, Pb, and Fe, were detected using ICP-OES method. Contamination of bottom sediments with potentially toxic metals was determined based on the geo-accumulation index (Igeo), contamination factor (CF), and pollutant load index (PLI). Statistical analyses were performed using the Statistica PL 13.1. The analyses showed that the accumulation of trace elements in the surface layer of the reservoir sediments increases as follows: in Borków, Cd < Co < Ni < Cu < Pb < Cr < Zn < Mn < Fe; in Wilków, Cd < Co < Cu < Ni < Pb < Cr < Zn < Mn < Fe; and in Rejow, Cd < Co = Cu = Ni = Pb < Zn < Cr < Mn < Fe. It was shown that the average distribution of metals in the bottom sediments of the studied reservoirs was as follows: Borków > Wilków > Rejów. Research has shown that the degree of trace metal accumulation increases as follows: water < sediments < macrophytes (except Pb from the reservoir in Borków).