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Fractured carbonate reservoirs are significantly developed in the eastern area of the Amu Darya Right Bank. However, their types, distributions, and fracture characteristics remain unclear. This uncertainty complicates reservoir prediction and hampers exploration and development processes. Given the strong correlation between fracture development and productivity, analyzing fractures is crucial. Comprehensive evaluation and prediction methods for fractured reservoirs are essential for advancing the oil and gas industry. Based on core and geological data analyses, it finds that these reservoirs exhibit low porosity and low to ultra-low permeability. By employing conventional logging alongside specialized methods, such as electrical imaging, nuclear magnetic resonance, and far detection logging, fractures and their effectiveness can be identified and evaluated, clarifying the characteristics of reservoir spaces. Constrained by the results from core and logging analyses, seismic single attribute analysis techniques is applied to predict fractures in the HX block of Amu Darya. To mitigate the limitations of single-attribute analysis, utilize a well-supervised BP neural network method for comprehensive fracture prediction. This multi-attribute approach increases the fracture prediction probability from less than 70%–72.7%. By integrating geological understanding and well logging, and considering the influence of lithology and structure on the reservoir, synthesize the fracture prediction results to optimally select favorable areas. [ABSTRACT FROM AUTHOR]

Examining the chemical properties of river water and the controlling factors is crucial for devising efficacious strategies in water resources management and ecological conservation. This study investigates the hydrochemical characteristics and driving factors of the Beichuan River in the arid region of Northwest China. Surface water samples were collected during wet and dry seasons, and analyzed using hydrochemical diagrams, mathematical statistics, and principal component analysis (PCA). The results show that the pH value of Beichuan River is generally weakly alkaline, the main hydrochemical types are HCO3-Ca, and the average TDS are 224 mg/L and 236 mg/L respectively, which are higher than the world average level (115 mg/L). The seasonal variation of hydrochemical components is mainly controlled by rainfall, showing that the concentrations of Na+, Cl− and NO3 − in the wet season are higher than those in the dry season, while the concentrations of other chemical components show an opposite trend, while the spatial variation is mainly controlled by human activities, and the concentrations of hydrochemical components show a gradual increasing trend from upstream to downstream, especially Na+, Mg2+, Cl− and NO3 − . Rock weathering is the key natural factor controlling the Hydrochemical Composition of Beichuan River. Na+ and Cl− are mainly from the dissolution of silicate, Ca2+ and Mg2+ are mainly from the weathering of carbonate rocks and silicate, and SO4 2- is mainly from the dissolution of evaporite. It is noted that human activities, especially domestic sewage and agricultural runoff, contribute significantly to NO3 − in the water body. PCA identified rock weathering and agricultural runoff as major wet-season factors, while domestic sewage predominantly affects the dry season. This study can provide a scientific basis for the rational development of water resources and ecological environment protection in arid areas. [ABSTRACT FROM AUTHOR]

With increasing emphasis on low-carbon environmental protection, CO2 enhanced coalbed methane production and methane reuse in abandoned mines (rich in N2) have gradually become one of the future development directions. These scenarios involve the coordinated migration of different gases such as CO2, CH4, and N2, and the differences in properties of different gases that affect the flow process. Previous studies often focused on the adsorption differences between gases, neglecting the differences during desorption process. In view of this, the current work conducted experiments and finite element numerical analysis on the desorption process of CO2, CH4, and N2, clarified the differences and influencing factors of desorption among the gases, and analyzed the flow change rules under different permeability and diffusion capabilities. The results indicated that the main differences among CO2, CH4, and N2 during desorption are reflected in the parameters of Langmuir volume, permeability, and diffusion coefficient. These parameters showed that CO2 has the highest value during desorption, while N2 has the lowest. The factors affecting the magnitude of differences between CO2, CH4, and N2 are mainly their compositions. Specifically, ash content significantly affects the difference in adsorption capacity, while moisture content influences permeability and diffusion coefficient. During desorption, permeability plays a continuous role throughout the whole process, while diffusion coefficient is exhibited mainly in the initial stage of desorption. Different gases have varying sensitivities to permeability and diffusion coefficients during desorption. Changes in permeability and diffusion coefficient significantly affect the CO2 desorption process. N2, on the other hand, is the least sensitive, especially to changes in diffusion coefficient. During gas flow, when reservoir permeability is less than 0.01 mD (= 9.869233 × 10−18 m2), permeability becomes the main factor that affects flow. When the diffusion coefficient is less than 5 × 10−9 m2/s, increasing the diffusion coefficient is necessary to effectively promote gas outflow. To effectively increase gas production, it is necessary to comprehensively consider the magnitudes of permeability and diffusion coefficient. [ABSTRACT FROM AUTHOR]

A special type of sandstone in which carbonate rock fragments (CRFs) dominate the composition developed in the Upper Triassic Xujiahe Formation's fourth member (Xu4) in the western Sichuan Basin, known as calcareous sandstone. Calcareous sandstones are widely distributed in the western Sichuan and is the main production target of tight sandstone gas in the Sichuan Basin. In this study, thin sections, porosity–permeability testing, scanning electron microscopy, and X-ray diffraction are applied to examine the characteristics and control factors for high-quality reservoirs in the calcareous sandstones, with a view to providing guidance for natural gas exploration and development in calcareous sandstones. The results show that the calcareous sandstone belongs to litharenite, with an average framework grain composition of 30% quartz, 1% feldspar, and 69% rock fragments, while the Xu4 sandstone has a high quartz content (average content of 71%). Primary intergranular pores are the main storage space, and the reservoir quality is quite poor. Under the influence of different parent rock properties of sandstones, there are obvious differences in the composition of framework grains between the calcareous sandstone and the ordinary Xu4 sandstone, which in turn affects the reservoir storage space, diagenesis, and reservoir quality. High-energy depositional conditions, low content of late cements, and the development of fractures are the main controlling factors for the formation of high-quality reservoirs in Xu 4 calcareous sandstones. [ABSTRACT FROM AUTHOR]

Shape memory alloys (SMAs) are potential materials in various areas such as engineering and medicine, and their applications are being studied for practical use. SMAs show competence in their main material properties in response to their working environment or external stimuli. Machining of NiTiCu10 SMAs is difficult using traditional machining because of their wide-ranging mechanical properties like high toughness, strength, and sensitivity to phase transformation temperature. Nonconventional machining methods such as electro-discharge machining (EDM) are suitable for effective machining SMAs. The work material NiTiCu10 SMA has been used in this study, and processed using the vacuum induction melting (VIM) technique. The addition of copper leads to increase in the martensitic transformation temperatures. This paper focuses on the electro-discharge drilling (EDD) of NiTiCu10 SMA using copper tool electrode. Experimental analysis of performance criteria has been evaluated by conducting experiments following one factor at a time (OFAT) approach. Machining features such as material removal rate (MRR), tool electrode wear rate (TEWR), and surface roughness (SR) have been studied by considering pulse current ( I p ), gap voltage ( V g ), pulse on time ( T on ), pulse off time ( T off ), and rotational speed of tool electrode (N). Experimental results have shown that machining at the highest I p of 12 A yields the highest MRR with the value of 4.077 mm3/min, whereas mcahining at T on of 15 μ s yields the lowest TEWR with the value of 0.031 mm3/min. The lowest SR is 2.8 μ m achieved at the lowest T on of 15 μ s. Surface morphology is significant in quality evaluation in the manufacturing, and building industries because it directly determines the mechanical performance of parts, and the service life of products. Morphological investigation via scanning electron microscope (SEM) has confirmed the formation of craters, debris, microcracks, and resolidified layers. The benefit of this study has been that we have been able to select the range of significant control factors, and predict their levels, for decisive experimentation. [ABSTRACT FROM AUTHOR]

In recent years, coal-type critical metal deposits have become a research hotspot in coal geology. As a major coal-accumulating basin in the Xinjiang area, the Turpan-Hami Basin contains abundant coal resources and has the potential to become a large coal-type critical metal deposit. However, previous studies on the enrichment characteristics of critical metal elements in coal are few and need further research. Based on SEM-EDS, XRF, and ICP-MS experiments, this study investigates the coal petrology, mineralogy, and geochemistry of the No. 22 coal of the Xishanyao Formation from the Dananhu Coal Mine, Xinjiang, to identify the sediment source, depositional environment, and controlling factors of the critical metal elements of the No. 22 coal. The results showed that the Dananhu coals are characterized by a low ash yield, low total sulfur content, high volatile yield, and high inertinite proportions. Quartz, kaolinite, and illite are the main minerals in the coal. Compared with the world's low-rank coals, Ni, Co, Mo, and Ta are slightly enriched, Li, Rb, Cs, Ba, Tl, Bi, and Ge are depleted, and the concentrations of other trace elements are comparable to the average values of the world's low-rank coals. The REY of the Dannanhu coals exhibited high fractionation, with its enrichment patterns characterized by the H-type and M-H-type. Although most of the critical metals are not enriched in the Dannanhu coals, the Ga, Zr (Hf), and Nb (Ta) concentrations in the coal ash of the Dannanhu coals have reached the economic cut-off grade and have the potential to be a substitute for rare metal resources. The terrigenous detrital sources of the Dannanhu coals mainly come from the Paleozoic dacite, andesite, and a small amount of granite from the Harik Mountain and Eastern Bogda Mountain in the Turpan-Hami Basin. The Dannanhu coals are generally in a dry and hot depositional environment, with high salinity and weak reduction-oxidation. The low source input and weak reduction-oxidation environment have resulted in low concentrations of critical metal of the No. 22 coal from the Dananhu Coal Mine. [ABSTRACT FROM AUTHOR]

Fractured carbonate reservoirs are significantly developed in the eastern area of the Amu Darya Right Bank. However, their types, distributions, and fracture characteristics remain unclear. This uncertainty complicates reservoir prediction and hampers exploration and development processes. Given the strong correlation between fracture development and productivity, analyzing fractures is crucial. Comprehensive evaluation and prediction methods for fractured reservoirs are essential for advancing the oil and gas industry. Based on core and geological data analyses, it finds that these reservoirs exhibit low porosity and low to ultra-low permeability. By employing conventional logging alongside specialized methods, such as electrical imaging, nuclear magnetic resonance, and far detection logging, fractures and their effectiveness can be identified and evaluated, clarifying the characteristics of reservoir spaces. Constrained by the results from core and logging analyses, seismic single attribute analysis techniques is applied to predict fractures in the HX block of Amu Darya. To mitigate the limitations of single-attribute analysis, utilize a well-supervised BP neural network method for comprehensive fracture prediction. This multi-attribute approach increases the fracture prediction probability from less than 70%–72.7%. By integrating geological understanding and well logging, and considering the influence of lithology and structure on the reservoir, synthesize the fracture prediction results to optimally select favorable areas.

As one of the important indicators for evaluating the quality of pears, stone cells exhibit a supportive effect on pear fruits and improve its storability. However, excess stone cells in pear fruits are not conducive to the accumulation of nutrients, affecting the taste, flavor and health benefits, ultimately reducing the marketability of pears. Gaining insights into the formation pathways of stone cells and developing methods to regulate the formation of stone cells are beneficial to improve the quality of pear fruits and promote the development of processed pear products. In this article, we review the key internal factors controlling the development of stone cells in pear fruits such as enzymes, lignin, vascular bundles and genes and the external factors affecting the distribution, size and content of stone cells in pear fruits such as exogenous calcium, hormones, and the environment. Moreover, we also discuss the effects of stone cells on the sensory and nutritional quality of pear fruits. It is our hope that this review will provide a reference for the deep processing and utilization of pear fruits in the future.

This study takes the tight sandstone of the lower sub‐member of the first member of the Eocene Shahejie Formation (Es1x) in the Suning area, Raoyang Sag, Bohai Bay Basin. Furthermore, it determines the rock type of the middle‐deep tight sandstone through lithologic profiling, core observation and log data analysis. The genetic control factors of tight sandstone in the study area are analysed using conventional thin section, pore‐casted thin section and scanning electron microscope, and the characteristics and genetic control factors of tight sandstone reservoirs are summarized. The research results show that the tight sandstones in this area are primarily feldspathic sandstone and feldspathic lithic sandstone, with high quartz contents, around 61.50%. The average porosity of the reservoir in the study area is 4.69%, and the average permeability is 2.92 mD, which are characteristics of low‐porosity and low‐permeability reservoirs. Through research, it has been found that the distribution of sedimentary facies and diagenesis in the study area control the development and distribution of 'sweet spots'. Both compaction and cementation reduce the physical properties of the reservoir, while dissolution can increase porosity, thereby increasing the physical properties of the reservoir; dissolution resulted in an increase of approximately 3.57%–3.69% in the porosity of the tight reservoir in the study area, with an average porosity increase of 3.63%, and is the main controlling factor for the development of 'sweet spots' in the reservoir. The results provide an important basis for guiding the exploration and development of tight sandstone oil and gas in the lower sub‐member of the first member of the Eocene Shahejie Formation (Es1x)in the Suning area. [ABSTRACT FROM AUTHOR]

Submarine geohazards significantly threaten human economic activities and essential infrastructure. Based on multi‐beam data and high‐resolution 2D seismic data, two types of submarine geohazards are identified: direct and indirect geohazards on the northwestern continental slope and the Xisha Uplift of the South China Sea (SCS). Direct geohazards include submarine landslides and active faults, while indirect geohazards include buried channels, submarine canyons, pockmarks, volcanoes and magma diapirs. This study comprehensively analyzes geomorphological features, including their characteristics, genesis and distribution. Statistical analysis reveals that the gradient of the Xisha Uplift slope is steeper than the shelf break, making it a more unstable region. However, assessing disaster potential indicates that submarine geohazards at the shelf break pose a greater threat than those at the Xisha Uplift. Many factors, including tectonic activity, sediment supply and relative sea‐level changes, influence submarine geohazards' formation. These hazards do not occur in isolation but often interact with one another. The research results provide a scientific basis for predicting deep‐sea geohazards near the northern continental margin and Xisha Island in the SCS. [ABSTRACT FROM AUTHOR]

[Significance] The formation and preservation of large-scale oolites in marine environments are valuable tools in climate and environmental evolution studies, and also hold considerable importance as petroleum reservoirs. However, traditional studies on oolites have focused primarily on their depositional sequences, patterns and spatial distribution, almost overlooking the dynamic processes of ooid shoal accumulation, burial and diagenesis, as well as the influence of environmental controls on their development. [Progress] This study aims to address this gap by a comprehensive analysis of typical ooid factories (rimmed shelves and ramps) in modern marine environments. It examines their producers, composition, distribution, construction process, relationship with other carbonate factories and the physical, chemical and biological factors influencing their development. It was found that the key limiting factors on the development of ooid factories include strong turbulent water conditions, high carbonate mineral saturation, and effective active-stationary stage transitions. Additionally, the developmental environment and scale of these factories are determined by their specific depositional backgrounds. [Conclusions and Prospects] From a carbonate factory perspective, this study provides important insights into the initiation-flourishing-decline processes of large-scale ooid factories, and offers multidimensional evidence for evaluating their value in oil and gas exploration. Furthermore, it provides new insights for exploring the deep-time environment and predicting future changes on carbonate depositional systems. [ABSTRACT FROM AUTHOR]

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Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Northeast Petroleum University is the property of Journal of Northeast Petroleum University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to accurately and quickly predict the coal seam gas occurrence and determine its control factors, the gas occurrence law of No.10 coal seam in Luling Coal Mine was analyzed by using the sub-source forecast method and fuzzy matter-element evaluation method. The evaluation of control factors of gas occurrence was carried out. The results show that the gas emission of No.10 coal seam is generally high, with the distribution characteristics of high in the central and western regions and low in the southeast. Its gas emission increases with the increase of depth, and the emission range is 9.23-16.11 m3/t. Applying control factor analysis, the study area is classified into three types of regions: the shallow area in southwest is considered as type I, and the deep area in northeast is predominantly considered as class II and III.

Catastrophic landslides occur frequently in Guizhou Province, China, and the landslides in this area have special geomorphological, geological, and anthropogenic features. In order to detect and explore the distribution pattern and control factors of active landslides in Guizhou, firstly, a total of 693 active landslides throughout Guizhou Province were mapped based on the deformation rate, which was obtained by spatiotemporal filtering and Intermittent Small Baseline Subset (ISBAS) Interferometric Synthetic Aperture Radar (InSAR) techniques. Then, the relationships between the detected landslides and elevation, aspect, slope gradient, and stratigraphic lithology were analysed. Moreover, it was found that the landslides were mainly concentrated in three stratigraphic combinations, that is T 1 f ~ P 2 l − d , T 1 f ~ T 1 y n , and T 2 g ~ T 1 y n . Thereafter, the correlation coefficients between the landslide density and elevation and distance to the stratigraphic boundary were 0.54 and −0.19, indicating that the distribution of landslides was significantly controlled by the elevation and the boundary of specific stratigraphic combinations. Finally, we chose a typical landslide to explore how landslide development was controlled by the combined effects of elevation and stratigraphy by using ascending and descending InSAR results. We revealed that landslides occurred primarily in areas with a steep slope and a stratigraphy characterized by mudstone and sandstone. [ABSTRACT FROM AUTHOR]

The late Paleozoic Fengcheng Formation shale (LPF shale) in the Junggar Basin, NW China, is the oldest alkaline source rock discovered in the world, providing a unique perspective with which to explore organic matter (OM) enrichment in alkaline lake environments. Combined with the organic carbon isotope profile and paleoenvironmental proxies, this study reveals that the LPF shale was deposited in an arid climate with high salinity and a strong reducing environment, accompanied by frequent volcanic activity. High TOC values are concentrated in two intervals with frequent fluctuations in OM types. A negative excursion due to changes in sedimentary OM source is found in the δ13Corg profile. The excursion corresponds to the OM enrichment interval and is accompanied by abnormally high values of Sr/Ba and Sr/Cu. This implies that the extreme arid climate has led to high salinity, resulting in strong reducibility and changes in paleontological assemblages, which in turn controlled the differential enrichment of OM. The Fengcheng Fm. high‐quality source rocks are the result of the combined action of climatic events, volcanism, high‐salinity water environment and superior hydrocarbon‐generating organisms. The results provide new insights into the formation conditions of terrestrial alkaline high‐quality source rocks and the factors controlling alkaline OM enrichment. [ABSTRACT FROM AUTHOR]

The ecological environment of the northwest inland basin is fragile. The groundwater environment is a crucial influencing factor for the harmonious and sustainable development of the local social economy and the ecological environment. It is significant to investigate the groundwater chemical characteristics, water quality, and the factors that influence groundwater chemistry for groundwater resources development and construction of the ecological environment. In this study, the Jinta Basin (JB), Gansu Province, was the selected study area. Three hundred and fifty groups of shallow groundwater samples in the JB were collected and analyzed, and the characteristics and controlling factors of groundwater were determined by using Piper diagram, Gibbs plot, ion ratio relationship, and factor analysis. Single index evaluation method, comprehensive evaluation method, and entropy-weighted water quality index method were used to evaluate the water quality of the groundwater. The results indicated that the shallow pore water in the JB was alkaline as a whole; the ranges of total dissolved solids (TDS) in the Beidahe River impact area (BIA), the transition area (TA) and the Heihe River impact area (HIA) were 328.4–12,400 mg·L−1, 372.70–3774.0 mg·L−1, and 366.30–75,200.0 mg·L−1, respectively; the major anions and cations of the shallow pore water were SO42−/Cl− and Mg2+/Na+, respectively. The Piper diagram illustrated that the hydrochemical type of groundwater in the JB were mainly HCO3·SO4-Mg type, SO4·HCO3-Mg type, SO4-Mg·Na type, SO4·Cl-Na·Mg type, and Cl-Na type. The overall water quality of the shallow groundwater in the JB was relatively poor, mainly falling into Class IV-V water quality. Sulfate, total hardness (TH), TDS, chloride and sodium were the main influencing factors of water quality. The chemical characteristics of groundwater in the JB were controlled by a variety of natural factors, including rock weathering, evaporative concentration, and cation exchange, among which the main controlling factors of shallow pore water were leaching, evaporative concentration and anthropogenic activities (contribution rate of 73.94%), and sulfate rock and carbonate rock dissolution (contribution rate of 14.91%). [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Submarine canyon is an important channel for long-distance sediment transport, and an important part of deep-water sedimentary system. The large-scale Rizhao Canyons have been discovered for the first time in 2015 in the continental slope area of the western South China Sea. Based on the interpretation and analysis of multi-beam bathymetry and two-dimensional multi-channel seismic data, the geology of the canyons has however not been studied yet. In this paper, the morphology and distribution characteristics of the canyon are carefully described, the sedimentary filling structure and its evolution process of the canyon are analyzed, and then its controlling factors are discussed. The results show that Rizhao Canyons group is a large slope restricted canyon group composed of one east–west west main and nine branch canyons extending to the south. The canyon was formed from the late Miocene to the Quaternary. The east–west main canyon is located in the transition zone between the northern terrace and the southern Zhongjiannan Slope, and it is mainly formed by the scouring and erosion of the material source from the west, approximately along the slope direction. Its development and evolution is mainly controlled by sediment supply and topographic conditions, the development of 9 branch canyons is mainly controlled by gravity flow and collapse from the east–west main canyon. This understanding result is a supplement to the study of "source-channel–sink" sedimentary system in the west of the South China Sea, and has important guiding significance for the study of marine geological hazards. [ABSTRACT FROM AUTHOR]

Polder is usually used for flood control in the river delta area. With the rapid development of urbanization, the dikes or pumps cut the original stream network system, and the stream network connectivity (SNC) and the river system pattern have changed. The dikes or pumps generally force up the river's water level, and regional flood formation mechanisms and processes have changed. In order to quantitatively describe the characteristics of polder‐type flood control measure (PFCM) and the change law of SNC, firstly, the streams inside polders were generalized as virtual streams, a hydrological‐hydrodynamic model was constructed by connecting Hydrologic Engineering Center‐Hydrologic Modeling System and MIKE11 model. Secondly, an SNC evaluation model was constructed based on flow resistance and hydrological process. Finally, the SNC under different scenarios was simulated and evaluated to reveal the influence of the PFCM on SNC. And the dominance analysis method obtained the main control factors of SNC changes. The results showed that the pumps as the main drainage facility under the PFCM, SNC after the opening of the pumps were increased by 0.060, 0.103, and 0.311 for 50%, 30%, and 3% frequency flood scales compared with the pumps closed, respectively. However, compared with the natural stream (without the PFCM), the SNC decreased by 0.391, 0.456, and 0.487, respectively, at the same time of the same flood scale. The PFCM negatively impacted the SNC, and the number of pumps was the main control factor of the SNC. [ABSTRACT FROM AUTHOR]

Copyright of Acta Sedimentologica Sinica is the property of Acta Sedimentologica Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Aksu River, a quintessential inland river, exhibits elevated arsenic (As) concentrations in certain sections of its natural waters. Further investigation is necessary to determine the role of surface water and groundwater (SW-GW) exchanges in contributing to these high As concentrations. Both surface water and groundwater constitute crucial components of the basin water cycle, and the interaction between the two has been a central focus in basin water cycle research. In this study, a total of 59 groundwater samples and 41 surface water samples were collected along the river's course within the basin. Among the groundwater samples, 18.64% exceeded the permissible drinking limit for As concentrations (10 μg/L), while 39.02% of the surface water samples exceeded this threshold. The water bodies in the Aksu River Basin are mildly alkaline, with total dissolved solids (TDSs) in surface water significantly surpassing those in groundwater. The chemical compositions of surface water and groundwater are strikingly similar, with the predominant anions being chloride (Cl−) and sulfate (SO42−) and the principal cations being sodium (Na+). The dissolution of silicate and carbonate minerals primarily influences the water chemistry characteristics of surface water and groundwater in the Aksu River Basin, followed by the dissolution of salt rocks. Human activities also play a major role in affecting the river's water quality. The distribution of groundwater with elevated As content is entirely encompassed within the spatial distribution of surface water. Groundwater–surface water exchange plays a vital role in As enrichment in surface water. [ABSTRACT FROM AUTHOR]

Abstract With the continuous improvement of oil and gas exploration in the middle and shallow layers, the deep Paleogene in Raoyang sag has become an important exploration field of “increasing reserves and production” in North China. The recognition and control factors of deep effective reservoirs are unclear, which restricts the recognition effect of oil and gas exploration. The key to identify effective reservoirs is to determine the lower limit standard of reservoir physical properties. The single method for calculating the lower limit of physical properties has limitations. The lower limit of the effective reservoir physical properties of the Shahejie Formation in the Dawangzhuang area was obtained by comprehensively using physical property, well logging and oil test data. The data were analysed by oil testing method, metre oil production index test method and frequency curve intersection method. On this basis, combined with the cast thin-section observations, scanning electron microscopy and other test results, the comprehensive control of effective reservoir development of the Shahejie Formation in the Dawangzhuang area of the Raoyang sag was studied from various factors, such as formation pressure, sand body thickness and diagenesis. The results show that the lower limit of porosity was 9.73, 9.44 and 8.85% at depths of Es1, Es2 and Es3, respectively. The lower limit of permeability was 1.21 × 10–3, 1.18 × 10–3 and 0.59 × 10–3 μm2, respectively. Effective reservoirs are easier to form in areas with formation pressure coefficient greater than 1.2. Formation overpressure inhibits compaction and promotes dissolution. The proportion of effective reservoirs of sand bodies with thicknesses greater than 2 m can reach more than 75%. The influence of diagenesis on the reservoir is mainly manifested in compaction and cementation making the reservoir compact. The porosity reduction rate caused by compaction can reach 20–75%, while dissolution makes the reservoir form secondary pores. The average pore throat radius of secondary pores can reach 4 ~ 6.3 µm. This study makes use of the applicability of different methods, which is more instructive for predicting the effective reservoir of the Shahejie Formation in the study area. In addition, the research results provide a reference for the development mechanism of medium-deep clastic reservoirs.

The seepage mechanism plays a crucial role in low-permeability gas reservoirs. Compared with conventional gas reservoirs, low-permeability sandstone gas reservoirs are characterized by low porosity, low permeability, strong heterogeneity, and high water saturation. Moreover, their percolation mechanisms are more complex. The present work describes a series of experiments conducted considering low-permeability sandstone cores under pressuredepletion conditions (from the Xihu Depression in the East China Sea Basin). It is shown that the threshold pressure gradient of a low-permeability gas reservoir in thick layers is positively correlated with water saturation and negatively correlated with permeability and porosity. The reservoir stress sensitivity is related to permeability and rock composition. Stress sensitivity is generally low when permeability is high or in the early stage of gas reservoir development. It is also shown that in sand conglomerates, especially the more sparsely filled parts, the interstitial materials among the conglomerates can be rapidly dislodged from the skeleton particles under stress. This material can therefore disperse, migrate, and block the pore throat producing serious, stress-sensitive damage. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Northeast Petroleum University is the property of Journal of Northeast Petroleum University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the combined exploitation efficiency of horizontal and vertical wells, and given the fact that the complex and varied spatial structure of sand bodies in the Fuyu oil layer in the Qian'an area of Songliao Basin leads to significant differences in production characteristics of horizontal wells, the sand body types and internal spatial structure are finely dissected according to the theory of configuration analysis, and the internal spatial structure is divided into three configuration styles: spatial clipping type, overlapping type, and separation type. Then, by comparing the productivity characteristics of horizontal wells with different configurations of sand bodies, combined with the analysis of fluid flow law under horizontal well volume fracturing, a main fracture–fracture network–matrix coupled fluid flow model in a tight reservoir based on composite sand body configuration is established. Combined with the actual volume fracturing the horizontal well area, the productivity curves of each cluster in the horizontal section after numerical simulation of volume fracturing of typical horizontal well groups are extracted, which are divided into four types: high-yield stable type, high-yield two-stage type, high-yield rapid-decline type, and low-yield rapid-decline type, and the coupling relationship between the productivity characteristics of each cluster in the horizontal well volume fracturing and sand body configuration style is established, which provides a theoretical basis for the adjustment of different sand body development methods in subsequent oilfields. [ABSTRACT FROM AUTHOR]

With the continuous improvement of oil and gas exploration in the middle and shallow layers, the deep Paleogene in Raoyang sag has become an important exploration field of "increasing reserves and production" in North China. The recognition and control factors of deep effective reservoirs are unclear, which restricts the recognition effect of oil and gas exploration. The key to identify effective reservoirs is to determine the lower limit standard of reservoir physical properties. The single method for calculating the lower limit of physical properties has limitations. The lower limit of the effective reservoir physical properties of the Shahejie Formation in the Dawangzhuang area was obtained by comprehensively using physical property, well logging and oil test data. The data were analysed by oil testing method, metre oil production index test method and frequency curve intersection method. On this basis, combined with the cast thin-section observations, scanning electron microscopy and other test results, the comprehensive control of effective reservoir development of the Shahejie Formation in the Dawangzhuang area of the Raoyang sag was studied from various factors, such as formation pressure, sand body thickness and diagenesis. The results show that the lower limit of porosity was 9.73, 9.44 and 8.85% at depths of Es1, Es2 and Es3, respectively. The lower limit of permeability was 1.21 × 10–3, 1.18 × 10–3 and 0.59 × 10–3 μm2, respectively. Effective reservoirs are easier to form in areas with formation pressure coefficient greater than 1.2. Formation overpressure inhibits compaction and promotes dissolution. The proportion of effective reservoirs of sand bodies with thicknesses greater than 2 m can reach more than 75%. The influence of diagenesis on the reservoir is mainly manifested in compaction and cementation making the reservoir compact. The porosity reduction rate caused by compaction can reach 20–75%, while dissolution makes the reservoir form secondary pores. The average pore throat radius of secondary pores can reach 4 ~ 6.3 µm. This study makes use of the applicability of different methods, which is more instructive for predicting the effective reservoir of the Shahejie Formation in the study area. In addition, the research results provide a reference for the development mechanism of medium-deep clastic reservoirs. [ABSTRACT FROM AUTHOR]

This study clarified the sedimentary characteristics of hyperpycnal flow sediments, investigated the plane and vertical characteristics and the differences in hyperpycnal flow sedimentary systems from different provenances, and finally discussed the controlling factors of hyperpycnal flow in rift basins. The sedimentary characteristics of hyperpycnal flow in the Lower Shahejie Formation of the Qikou Sag, Bohai Bay Basin have been studied through the comprehensive analysis of drilling core, logging, seismic attribute, and grain data.The results show that there are three typical recognition features for the hyperpycnal flow deposits in the study area: ① The vertical sedimentary sequence is composed of a reverse grain grading in the lower part, a normal grain grading in the upper part and a relatively thick layer with no obvious change in grain size; ② The sediment is dominated by a gradual suspension. The types of cumulative probability curves include a complex multistage style, an upper arch style and a low slope two-stage style; ③ The lithofacies is characterized by erosional filling deposition and various bedding structures with the development of maroon argillaceous layers, maroon gravels, abundant plant debris and carbonaceous debris. The channelized hyperpycnal flow sediments have multiple sources. The most significant source is the Gegu source, which is characterized by a long-distance transportation path, multiple flower bodies and widespread deposits along the transportation path.Two types of sedimentary models are established in this study, and the controlling factors of hyperpycnal flow include paleogeomorphology, paleoprovenance and paleoclimate. Considering that hyperpycnal flow widely exists in rift lacustrine basins with its channel sandstone bodies being good reservoir properties, our study suggests that hyperpycnal flow is a breakthrough point for oil and gas exploration in continental rift lacustrine basins.

Copyright of Journal of Northeast Petroleum University is the property of Journal of Northeast Petroleum University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Magnetic nanomaterials are widely used in biosynthesis, catalysis, as electronic and microwave-absorbing materials, and in environmental treatment because of their high specific surface area, strong magnetism, chemical stability, and good biocompatibility. The chemical coprecipitation method is widely used for the preparation of magnetic nanomaterials due to its simplicity, low cost, and easily-controlled operating conditions. The magnetic nanomaterials prepared by the chemical coprecipitation method are summarized according to the different compositions, including the basic preparation principles, and the factors affecting their morphology, size, and microstructure. The mechanisms of preparing magnetic nanomaterials by chemical precipitation and the process control factors are emphasized. Finally, the preparation of magnetic nanomaterials by chemical coprecipitation is summarized and prospected. [ABSTRACT FROM AUTHOR]

Catastrophic landslides occur frequently in Guizhou Province, China, and the landslides in this area have special geomorphological, geological, and anthropogenic features. In order to detect and explore the distribution pattern and control factors of active landslides in Guizhou, firstly, a total of 693 active landslides throughout Guizhou Province were mapped based on the deformation rate, which was obtained by spatiotemporal filtering and Intermittent Small Baseline Subset (ISBAS) Interferometric Synthetic Aperture Radar (InSAR) techniques. Then, the relationships between the detected landslides and elevation, aspect, slope gradient, and stratigraphic lithology were analysed. Moreover, it was found that the landslides were mainly concentrated in three stratigraphic combinations, that is T1f~P2l−d, T1f~T1yn, and T2g~T1yn. Thereafter, the correlation coefficients between the landslide density and elevation and distance to the stratigraphic boundary were 0.54 and −0.19, indicating that the distribution of landslides was significantly controlled by the elevation and the boundary of specific stratigraphic combinations. Finally, we chose a typical landslide to explore how landslide development was controlled by the combined effects of elevation and stratigraphy by using ascending and descending InSAR results. We revealed that landslides occurred primarily in areas with a steep slope and a stratigraphy characterized by mudstone and sandstone.

Taking Miaoziping tunnel of E-Han expressway as the research object, firstly, through the geological survey, tracer test and statistics of the number of karst caves exposed on the site, the characteristics of karst development in the tunnel site are clarified and its control factors are analyzed, and then the engineering influence of karst development is explored based on sorting and analyzing the on-site monitoring data. The results show that: under the coupling action of multiple solution control factors, the karst in the tunnel site shows remarkable characteristics of heterogeneity, concentration, directivity and connectivity. Among them, rock strata lithology, topography, hydrogeology and geological structure mainly make karst development uneven and concentrated; hydrogeology and topography mainly control the direction of karst development and whether karst is connected; climate further promotes karst development. The engineering impact of karst development in the tunnel site area is mainly manifested as the impact of tunnel stability and tunnel water inflow. The scale and size of karst have a certain impact on the stability of the tunnel, but the scope of impact is relatively limited. However, the water inflow makes the tunnel accumulate water for a long time, which even makes the personnel and machinery flooded or destroyed in the rainy season, which has a serious impact on the safety, progress and economy of the tunnel. The conclusion can provide reference for the design, construction, karst disaster prevention and control of tunnel along the E-Han Expressway and other similar projects.

Copyright of Railway Investigation & Surveying is the property of Railway Investigation & Surveying Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To explore the chemical characteristics and environmental factors of groundwater in the Hetao Irrigation Area of Inner Mongolia, five irrigation fields, including UulanBuh, Jiefangzha, Yongji, Yichang, and Wulat, were selected as the research area. From 72 groundwater observation wells, a total of 216 groundwater samples were collected throughout three typical periods： the end of freeze-thaw （March）, the middle of irrigation （July）, and the end of autumn watering （November）. Comprehensive methods were utilized, such as statistical analysis, Piper three-line diagram, Gibbs diagram, ion ratio, and principal component analysis, to explore the changes in the groundwater chemical environment and the environmental driving factors of groundwater component formation. The groundwater drinking suitability was evaluated using the water quality index （WQI）, and the irrigation suitability was analyzed using the USSL and Wilcox plots. The results indicated that the groundwater in the research areas was generally saline, and the total anion and cation concentrations in each period in ascending order were as follows： late freeze-thaw stage, late autumn irrigation stage, and mid-irrigation stage, with Na + and Cl - being the major contributing ions. The chemical type of groundwater was dominated by Cl-Na, followed by Cl·SO 4 -Ca·Mg and a coexistence with SO 4 -Ca·Mg, HCO 3 ·Cl-Na, HCO 3 -Na, and HCO 3 -Ca·Mg. Based on WQI values, the shallow groundwater in Hetao Irrigation District was mainly classified as Class IV and Class V, and the quality was poor in general. According to the USSL diagram and Wilcox diagram, the comprehensive evaluation results showed that the salinity and sodium concentration of shallow groundwater in the irrigation area were generally high. A total of 80.6% of the water samples during the late freeze-thaw period, 76.1% during the mid-irrigation period, and 77.6% during the late autumn irrigation period lacked irrigation suitability. Two major controlling factors of groundwater chemical characteristics were present in the study area, namely, evaporation and rock weathering, and Na + and Cl - mainly came from the dissolution and cation exchange of salt rocks. Agricultural irrigation and drought were the chief driving factors of groundwater chemical evolution in the Hetao Irrigation Area. The study provides technical support for optimizing agricultural management measures and a theoretical reference for rational utilization of groundwater resources in the Yellow River irrigation area of Inner Mongolia.

Abstract The thermo-mechanical reliability of IMCs (Ni3Sn4, Cu3Sn, Cu6Sn5) solder joints and Sn-3.9Ag-0.6Cu solder joints was investigated systematically in 3D chip stacking structure subjected to an accelerated thermal cyclic loading based on finite element simulation and Taguchi method. Effects of different control factors, including high temperature, low temperature, dwell time of thermal cyclic loading, and different IMCs on the stress-strain response and fatigue life of solder joints were calculated respectively. The results indicate that maximum stress-strain can be found in the second solder joint on the diagonal of IMC solder joints array; for Sn-3.9Ag-0.6Cu solder joints array, the corner solder joints show the obvious maximum stress-strain, these areas are the crack propagated locations. The stress-strain and fatigue life of solder joints is more sensitive to dwell temperature, especially to high temperature; increasing the high temperature, dwell time, or decreasing the low temperature, can reduce the stress-strain and enlarge the fatigue life of solder joints. Finally, the optimal design in the 3D-IC structure has the combination of the Cu6Sn5/Cu3Sn, 373 K high temperature, 233 K low temperature, and 10 min dwell time. The fatigue lives of Sn-3.9Ag-0.6Cu under 218–398 K loading in the 3D assembly based on the creep strain are 347.4 cycles, which is in good agreement with experimental results (380 cycles).

Suspended sediment transport and deposition are crucial physical processes controlling the geomorphological evolution of estuaries and bays. Specially, under the context of worldwide coastal erosion, knowledge of the spatio-temporal distribution of suspended sediment concentration (SSC) and its associated sediment load have become increasingly important for bay management. However, our understanding of the mechanisms of suspended sediment dynamics continues to be hampered by the lack of high-resolution observations. Here, we present a study of the transport mechanisms and controlling factors of suspended sediment over Laizhou Bay. For this, we conducted continuous measurements of SSC, salinity, temperature, and flow velocity at nine stations throughout Laizhou Bay for one 25-h period during each of the spring and moderate tides. Based on these data, residual current, gradient Richardson numbers, and suspended sediment flux were calculated. Our results indicate that a strong current field occurs near the Yellow River mouth, corresponding to the zone with high SSC. The overall diffusion characteristics of suspended sediment are controlled by the tidal current field. Furthermore, our findings suggest that different degrees of stratification occur in the water column, which inhibit the effective vertical diffusion of suspended sediment; Higher water temperature was the main cause of stronger water column stratification of spring tide than moderate tide. Finally, our results reveal that the type of seabed sediment is an important factor controlling SSC by influencing resuspension flux. We conclude that the primary mechanisms controlling suspended sediment transport in Laizhou Bay are advection and tidal pumping, especially advection. Our research provides both a foundational reference for the sediment source-to-sink process from the Yellow River to the sea, as well as guideline implications for coastal engineering construction and channel dredging.

Baihetan Dam Site is characterized by complex geological and structural conditions. The unloading effect of rock mass is strong and the number of faults, dislocation zones, deep fractures and other weak structural planes develops there . During the construction period, human activities have seriously damaged the stability of the high and steep slope, and affect the long-term safe and stable operation of the dam. Combined with the geological materials, this paper analyzes the monitoring data of the abutment slope during the construction period and studies the law of the slope deformation in different elevations of the abutment on both banks. Based on geological data, a three-dimensional finite element model of slope is built, and numerical simulation is carried out by FLAC3D software during slope excavation and support. The rationality of the numerical simulation results is verified by monitor data, and then the dam deformation law of the high and steep slope on both sides is studied according to the results of numerical simulation and in combination with monitoring data. The results show that both sides of the abutment slope is stable during the construction period. [ABSTRACT FROM AUTHOR]