14 research outputs found

    Sedimentary characteristics of clay deposits associated with coal beds and their geological implications for the Eastern Yanzhou Coalfield, North China

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    5-15Coal geology, sedimentology, sequence stratigraphy, and geochemistry were used to study the depositional environment, formative mechanisms, and clay layers’ distribution of the Eastern Yanzhou Coalfield. The 3rd coal bed and its floor (roof) clay layer were formed in the inter- distributary settings of a river-dominated shallow-water delta system. Clay deposits under 16-1st and 16-2nd coal beds were formed during the transgressive process, whereas clay deposit under the 17th coal bed was formed in event transgression .Through chemical analysis, the clay stone under the 3rd coal bed was demonstrated to be influenced by the brackish water, differently, the clay stones under the 16-1st, 16-2nd, and 17th coal beds were influenced by sea water. The clay stone under the 3rd coal bed was affected by sea water longer than the clay stones of the 16-1st, 16-2nd or 17th coal beds. Also, the exposure time before the peat swamp of the 17th coal bed was longer than that under the 16-1st and 16-2nd coal beds. 3rd coal bed and clay layer were found to have the same distribution rule. Thicker beds were distributed in the south. In the north, the beds getting thinner indicated that the clay stone was formed in active depositional systems. 16-1st coal bed and its floor clay layer distribution reflected that transgression happened from south to north. The16-2nd coal bed and its floor clay layer distribution indicated that transgression happened from the northwest to southeast, and the 17th coal bed and its clay floor layer distributions demonstrated that the transgression happened in the event transgression

    Antibacterial Activity and Mechanism of Action of Sulfone Derivatives Containing 1,3,4-Oxadiazole Moieties on Rice Bacterial Leaf Blight

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    In this study, sulfone derivatives containing 1,3,4-oxadiazole moieties indicated good antibacterial activities against rice bacterial leaf blight caused by the pathogen Xanthomonas oryzaepv. pv. oryzae (Xoo). In particular, 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole revealed the best antibacterial activity against Xoo, with a half-maximal effective concentration (EC50) of 9.89 μg/mL, which was better than those of the commercial agents of bismerthiazole (92.61 μg/mL) and thiodiazole copper (121.82 μg/mL). In vivo antibacterial activity tests under greenhouse conditions and field trials demonstrated that 2-(methylsulfonyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole was effective in reducing rice bacterial leaf blight. Meanwhile, 2-(methylsulfonyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole stimulate the increase in superoxide dismutase (SOD) and peroxidase (POD) activities in rice, causing marked enhancement of plant resistance against rice bacterial leaf blight. It could also improve the chlorophyll content and restrain the increase in the malondialdehyde (MDA) content in rice to considerably reduce the amount of damage caused by Xoo. Moreover, 2-(methylsulfonyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole, at a concentration of 20 μg/mL, could inhibit the production of extracellular polysaccharide (EPS) with an inhibition ratio of 94.52%, and reduce the gene expression levels of gumB, gumG, gumM, and xanA, with inhibition ratios of 94.88%, 68.14%, 86.76%, and 79.21%, respectively

    Coexistence and Development Model of Multi-Minerals Dominated by Multilayer Magma Intrusion: A Case Study of Huanghebei Coalfield in North China Basin

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    The diversity of coal measure determines the occurrence state and spatial distribution complexity of mineral resources. Abundant resources have become an important part of geological resources and have attracted more and more attention. Coal measure and their overlying and underlying strata often coexist with various mineral resource types, and there is a certain relationship between their genesis and occurrence. In order to further enrich the theory of comprehensive exploration and coordinated development of multi-mineral resources, this paper takes the Huanghebei Coalfield as an example to systematically study the genesis mechanism and occurrence law of coal seam, coalbed methane, and coal-measure shale gas in Late Paleozoic and rich iron ore in Ordovician limestone underlie coal measure. The research is that: 1) The Late Paleozoic Carboniferous-Permian Marine facies, terrestrial facies, and transitional facies all developed in the coal-bearing area in the Huanghebei Coalfield, and the coal seams and mud shales developed well in Shanxi Formation and Taiyuan Formation. 2) Yanshanian magmatic intruded into Ordovician limestone. Contact metasomatism occurred between the ore-bearing hydrothermal fluids and the surrounding rocks, which led to skarn formation. The magnetite mineralization occurred in the metasomatism alteration process, and finally, the contact metasomatic iron deposit was formed; 3) Yanshanian magma intrusion has a significant impact on the generation of coal from coalbed methane and shale gas in the coal measures of Late Paleozoic. The magma carries a lot of heat by baking the coal seam and overlying shale, which is reflected explicitly in the increasing metamorphism degree of coal. Under the action of high temperature, the secondary gas of coal seam and coalbed methane increase sharply. The maturity and thermal evolution of organic matter in shale beds increased, and the shale gas entered a favorable range. The intrusion of magma greatly enhances the thermal evolution of organic matter in coal and shale, forming a variety of coals and promoting the generation and accumulation of coalbed methane and shale gas. At the same time, Mesozoic magmatic intrusion also controlled the formation of rich iron ores. According to the characteristics of mineral development and distribution in the study area, a multi-mineral development and distribution model of “coal - coalbed methane - shale gas - rich iron ore” coexists in the Huanghebei Coalfield, which is referred to as the “Huanghebei model”

    Periodic Characteristics of the Paleogene Tectonic Activity and Sedimentation Responses in the Deep-Water of Qiongdongnan Basin, South China Sea

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    In this study, the periodic evolution and characteristics of the Palaeogene tectonic activity in the deep-water area of the Qiongdongnan Basin were revealed through the identification and analysis of the regional angular unconformity and the characteristics of the periodic fault activity. In addition to a comprehensive analysis of the controls on sedimentary paleogeomorphologic background, sedimentary characteristics and evolution by periodic rifting are systematically discussed. The studies have shown that the tectonic activity of the Paleogene Qiongdongnan Basin underwent three separate rifting phases: Phase-I (T100–T80), Phase-II (T80–T70), and Phase-III (T70–T60). The early phase of rifting was dominated by strong differential block-fault settlement, while the later phase was gradually replaced by homogeneous settlement controlled by regional depressions and a small amount of fault activity, characterized by a weak-strong-weak evolution. From Phase-I to Phase-III, the paleo-geomorphology margin changed from a large gradient to a gentle gradient, the subsidence center moved from the initial basin margin to the later basin center, and the basin-marginal fans extended finitely before developing on a large lateral scale in the later Phase-III. Analyzing the characteristics of periodic tectonic evolution and sedimentation response is important for petroleum exploration in marine basins, such as locating economic reservoirs

    Design, Synthesis, and Insecticidal Activity of Novel Isoxazoline Diacylhydrazine Compounds as GABA Receptor Inhibitors

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    A series of isoxazoline derivatives containing diacylhydrazine moieties were designed and synthesized as potential insecticides. Most of these derivatives exhibited good insecticidal activities against Plutella xylostella, and some compounds exhibited excellent insecticidal activities against Spodoptera frugiperda. Especially, D14 showed outstanding insecticidal activity against P. xylostella (LC50 = 0.37 μg/mL), which was superior to that of ethiprole (LC50 = 2.84 μg/mL) and tebufenozide (LC50 = 15.3 μg/mL) and similar to that of fluxametamide (LC50 = 0.30 μg/mL). Remarkably, the insecticidal activity of D14 against S. frugiperda (LC50 = 1.72 μg/mL) was superior to that of chlorantraniliprole (LC50 = 3.64 μg/mL) and tebufenozide (LC50 = 60.5 μg/mL) but lower than that of fluxametamide (LC50 = 0.14 μg/mL). The results of electrophysiological experiments, molecular docking, and proteomics experiments indicate that compound D14 acts by interfering with the γ-aminobutyric acid receptor to control pests

    Design, Synthesis, and Insecticidal Activity of Novel Isoxazoline Diacylhydrazine Compounds as GABA Receptor Inhibitors

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    A series of isoxazoline derivatives containing diacylhydrazine moieties were designed and synthesized as potential insecticides. Most of these derivatives exhibited good insecticidal activities against Plutella xylostella, and some compounds exhibited excellent insecticidal activities against Spodoptera frugiperda. Especially, D14 showed outstanding insecticidal activity against P. xylostella (LC50 = 0.37 μg/mL), which was superior to that of ethiprole (LC50 = 2.84 μg/mL) and tebufenozide (LC50 = 15.3 μg/mL) and similar to that of fluxametamide (LC50 = 0.30 μg/mL). Remarkably, the insecticidal activity of D14 against S. frugiperda (LC50 = 1.72 μg/mL) was superior to that of chlorantraniliprole (LC50 = 3.64 μg/mL) and tebufenozide (LC50 = 60.5 μg/mL) but lower than that of fluxametamide (LC50 = 0.14 μg/mL). The results of electrophysiological experiments, molecular docking, and proteomics experiments indicate that compound D14 acts by interfering with the γ-aminobutyric acid receptor to control pests

    Characteristics of the stratigraphic reservoirs and caprocks of the geothermal resources in the Northwestern Shandong region

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    The genetic relationships between the stratigraphic textures, thickness changes, burial depths, and the characteristics of the geothermal zoning of the Cenozoic in the northwestern Shandong region were analyzed in this study. Methods involving segmented water temperature measurements of geothermal well drilling, wellhead hydrological surveys, geothermal reservoirs, and caprock thickness measurements and statistics were adopted. The following findings were revealed in this study's research results: (1) The Paleogene and Neogene reservoir types in the northwestern Shandong region were determined to be mainly water-bearing fine sandstone and medium-fine sandstone pores, with thick layered, interbedded, and zoned stratigraphic structures. The layered and zoned geothermal reservoirs were found to be primarily distributed in a zonal manner on the bedding plane and characterized by good regional continuity. The fine sandstone and medium-fine sandstone sections with well-developed pores and high water content levels were geothermal reservoirs, while mudstone sections were geothermal barriers. The reservoirs and barriers were characterized by interlayer structures; (2) The boundary between the sag basin and the uplifting was taken as the dividing line of the geothermal fields, and the geothermal areas in the northwestern Shandong region were divided into different geothermal fields, all belonging to the sedimentary basin's conductive geothermal resources; (3) The major geothermal reservoirs included the lower members of the Neogene Minghuazhen Formation, Guantao Formation, and Dongying Formation. The Quaternary argillaceous sediment and the mudstone in the upper member of the Minghuazhen Formation formed the caprocks in the study area. In this study, the macroscopic distribution laws of geothermal resources in the northwestern Shandong region were proposed and were considered to have practical significance for further exploration and development

    Magmatic Intrusion during the Yanshanian Period and Multi-Mineral Enrichment Mechanisms in the Eastern Margin of the North China Craton

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    The mineralization within the North China Craton (NCC) is intricately linked to Mesozoic large-scale extension in eastern China and is a consequence of a unified geodynamic tectonic background. Despite previous attempts to elucidate the relationship between large-scale mineralization and magmatic activity in the NCC, a lack of systematic research has hindered the identification of connections among deposits with inconsistent metallogenic ages. This study focuses on the coal measures of the Huanghebei Coalfield (HHBC) in western Shandong, presenting a regional magmatic–hydrothermal metallogenic system with a genetic connection. It delves into the intricate interplay between the multi-mineral enrichment mechanism, metallogenic regularity, and the NCC’s destruction. The findings reveal that: (1) Various stages of magmatic intrusion during the Yanshanian period significantly influenced the Late Paleozoic coal measures in the HHBC. The coal measures exhibit distinct ranks, ranging from medium-rank bituminous C to A and high-rank anthracite C, resulting in noticeable differences in gas generation among different coal ranks. The shale between the coal seams C5 and C7 emerges as excellent with a good hydrocarbon-generating capacity during the middle-maturity stage. (2) The “Intrusion along the rock layer type” proves most conducive to shale gas enrichment, while the “laccolith type” is more favorable for shale gas enrichment compared to “dike type” intrusions, which have a limited impact on shale gas enrichment. (3) The mineralization process of CBM, shale gas, and iron ore is influenced by Yanshanian-period magma. The enrichment degree of CBM and shale gas exhibits an inverse correlation with the distance from the magmatic intrusion. Iron deposits demonstrate a close association with the magmatic intrusion, with enhanced enrichment along the rock layer. The results indicate that the destruction of the NCC triggered intense metasomatism in the deep cratonic fluids, serving as the primary driving mechanism for large-scale mineralization during the Yanshanian period. Magmatic intrusions bring hydrothermal fluids conducive to mineralization, and the heat release from these intrusions promotes thermal evolution, hydrocarbon generation, and the enrichment of organic-rich strata

    Synthesis, Antibacterial Activity, and Mechanisms of Novel Indole Derivatives Containing Pyridinium Moieties

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    The development of effective antibacterial agents equipped with novel action modes and unique skeletons starting from natural compounds serves as an important strategy in the modern pesticide industry. Disclosed here are a series of novel indole derivatives containing pyridinium moieties and their antibacterial activity evaluation against two prevalent phytopathogenic bacteria, Xanthomonas oryzae pv. oryzicola (Xoc) and X. oryzae pv. oryzae (Xoo). A three-dimensional (3D)-QSAR model was adopted to discover higher activity like title compounds based on the Xoc antibacterial activity of the tested compounds. Compound 43 was consequently designed, and it displayed higher antibacterial activity as expected with the half-maximal effective concentration EC50 values of 1.0 and 1.9 μg/mL for Xoo and Xoc, respectively, which were better than those of the commercial drug thiodiazole copper (TC) (72.9 and 87.5 μg/mL). Under greenhouse conditions, the results of a rice in vivo pot experiment indicated that the protective and curative activities of compound 43 against rice bacterial leaf streak (BLS) and rice bacterial blight (BLB) were 45.0 and 44.0% and 42.0 and 39.3%, respectively, which were better than those of the commercial agent thiodiazole copper (38.0 and 37.9%, 38.6 and 37.0%) as well. Scanning electron microscopy images, defense enzyme activity tests, and proteomic techniques were utilized in a preliminary mechanism study, suggesting that compound 43 shall modulate and interfere with the physiological processes and functions of pathogenic bacteria
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