Pub Date : 2025-11-10DOI: 10.1016/j.coal.2025.104900
Ádám Nádudvari , Rosanna Maniscalco , Martina Forzese , Dorota Staneczek , Dariusz Więcław , Giovanni Silvio Cassarino , Ewa Szram , Leszek Marynowski
Hydrocarbons have been known in Sicily for centuries from oil seeps and bitumen-impregnated limestones, which were exploited in the 19th and early 20th centuries. In the 1950s, several shallow wells were drilled in the Sicilian Foreland with the aim of hydrocarbon production. The study focuses on oil and bitumen seeps in Sicily, southern Italy. The oil seeps occur on the surface in Madonna dell’Olio (MA) in the Madonie Mountains in northern Sicily. They are also present as bitumen-impregnated porous carbonates in the Ragusa Formation on outcrops and in the subsurface in the Hyblean Foreland in southeastern Sicily (Streppenosa, Castelluccio, and Tabuna mines). Oil seeps introduce hydrocarbons into the natural environment, where biodegradation occurs. As biodegradation increases, the organic sulfur content increases, while the proportion of pyrolytic organic sulfur within total organic sulfur decreases. The Rock-Eval’s Multi-Heating Rates method shows that the Ragusa bitumen is dominated by the heavy fraction, in contrast to the diesel oil dominance of MA. Distinct oil families represent individual sources: carbonates in the Sicilian Fold-and-Thrust Belt, and shales and carbonates in the Ragusa Hyblean foreland. The distribution of biomarkers indicates an early oil window for both the MA and Ragusa fluids, with MA hydrocarbons slightly more mature than Ragusa ones.
{"title":"Source of biodegraded oil seep and bitumen rock-impregnations from the Sicilian Orogen and Foreland (Italy): Rock-Eval 6/7S and GC-MS approach","authors":"Ádám Nádudvari , Rosanna Maniscalco , Martina Forzese , Dorota Staneczek , Dariusz Więcław , Giovanni Silvio Cassarino , Ewa Szram , Leszek Marynowski","doi":"10.1016/j.coal.2025.104900","DOIUrl":"10.1016/j.coal.2025.104900","url":null,"abstract":"<div><div>Hydrocarbons have been known in Sicily for centuries from oil seeps and bitumen-impregnated limestones, which were exploited in the 19<sup>th</sup> and early 20<sup>th</sup> centuries. In the 1950s, several shallow wells were drilled in the Sicilian Foreland with the aim of hydrocarbon production. The study focuses on oil and bitumen seeps in Sicily, southern Italy. The oil seeps occur on the surface in Madonna dell’Olio (MA) in the Madonie Mountains in northern Sicily. They are also present as bitumen-impregnated porous carbonates in the Ragusa Formation on outcrops and in the subsurface in the Hyblean Foreland in southeastern Sicily (Streppenosa, Castelluccio, and Tabuna mines). Oil seeps introduce hydrocarbons into the natural environment, where biodegradation occurs. As biodegradation increases, the organic sulfur content increases, while the proportion of pyrolytic organic sulfur within total organic sulfur decreases. The Rock-Eval’s Multi-Heating Rates method shows that the Ragusa bitumen is dominated by the heavy fraction, in contrast to the diesel oil dominance of MA. Distinct oil families represent individual sources: carbonates in the Sicilian Fold-and-Thrust Belt, and shales and carbonates in the Ragusa Hyblean foreland. The distribution of biomarkers indicates an early oil window for both the MA and Ragusa fluids, with MA hydrocarbons slightly more mature than Ragusa ones.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"312 ","pages":"Article 104900"},"PeriodicalIF":5.7,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145478232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-07DOI: 10.1016/j.coal.2025.104899
Shifeng Dai , James C. Hower , Robert B. Finkelman , Marina P. Ketris , Yakov E. Yudovich , Yutang Zhang , Jingjing Liu , Changqiu Zhao , Na Xu , Ian T. Graham , David French , Yu Liu , Ruiwen Yan , Zhengfu Zhao
The abundance of elements in coal is important not only because it provides a solid scientific and practical foundation for various geochemical comparisons, but also because it helps address broader questions in Earth Sciences. In this study, data on major and trace elements in global coals comprising hundreds of thousands of coal samples were compiled from peer-reviewed journal articles, books, various databases, dissertations, and technical reports. These data formed the basis for estimating element abundances in global coals presented in this study. All collected data were rigorously screened for reliability, and any records with questionable quality were excluded from the analysis. Boxplot analysis was then applied to estimate element abundances, and median values of ash yields and different forms of sulfur in global coals. The results primarily include the minimum and maximum values within the normal range; the median (the 50th percentile, representing the average abundance); and outliers for all global coals, low-rank coals, and medium- to high-rank coals. Additionally, these statistical parameters are also provided for coals from different major coal-forming periods (including Pennsylvanian (Late Carboniferous) and Early Permian, Late Permian, Late Triassic, Early and Middle Jurassic, Late Jurassic and Early Cretaceous, and Paleogene and Neogene), and Chinese coals and U.S coals.
{"title":"Abundances of elements in global coals","authors":"Shifeng Dai , James C. Hower , Robert B. Finkelman , Marina P. Ketris , Yakov E. Yudovich , Yutang Zhang , Jingjing Liu , Changqiu Zhao , Na Xu , Ian T. Graham , David French , Yu Liu , Ruiwen Yan , Zhengfu Zhao","doi":"10.1016/j.coal.2025.104899","DOIUrl":"10.1016/j.coal.2025.104899","url":null,"abstract":"<div><div>The abundance of elements in coal is important not only because it provides a solid scientific and practical foundation for various geochemical comparisons, but also because it helps address broader questions in Earth Sciences. In this study, data on major and trace elements in global coals comprising hundreds of thousands of coal samples were compiled from peer-reviewed journal articles, books, various databases, dissertations, and technical reports. These data formed the basis for estimating element abundances in global coals presented in this study. All collected data were rigorously screened for reliability, and any records with questionable quality were excluded from the analysis. Boxplot analysis was then applied to estimate element abundances, and median values of ash yields and different forms of sulfur in global coals. The results primarily include the minimum and maximum values within the normal range; the median (the 50<sup>th</sup> percentile, representing the average abundance); and outliers for all global coals, low-rank coals, and medium- to high-rank coals. Additionally, these statistical parameters are also provided for coals from different major coal-forming periods (including Pennsylvanian (Late Carboniferous) and Early Permian, Late Permian, Late Triassic, Early and Middle Jurassic, Late Jurassic and Early Cretaceous, and Paleogene and Neogene), and Chinese coals and U.S coals.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"311 ","pages":"Article 104899"},"PeriodicalIF":5.7,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145462071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-04DOI: 10.1016/j.coal.2025.104897
Yong Ma , Omid H. Ardakani , Dahua Li , Jianbin Ma , Ningning Zhong , Haiping Huang
<div><div>This study provides an extensive investigation of the origin, morphological evolution, pore structure, and flow behavior of organic matter (OM)-hosted pore systems in the overmature Wufeng–Longmaxi (W–L) shales of the Sichuan Basin, SW China, with implications for shale gas storage and production. Eleven core samples from the Wufeng and Longmaxi formations, spanning a wide range of total organic carbon (TOC) content (0.47–5.48 wt%) but consistently high thermal maturity (EqVRo 3.89–4.20 %), were analyzed using a combination of geochemical analyses, optical microscopy, high-resolution scanning electron microscopy (SEM), three-dimensional focused ion beam-SEM (FIB-SEM) reconstructions, energy dispersive spectroscopy (EDS), and Navier–Stokes-based pore-scale permeability simulations. The OM assemblage comprises pyrobitumen, alginite, graptolites, and fecal pellets, each contributing distinct pore-forming pathways controlled by original ultrastructure, depositional redox conditions, and subsequent diagenetic mineralization. Alginite preserves sponge-like cellular ultrastructures, yielding highly connected macropore networks (> 50 nm), with the highest porosity (> 10 %) and permeability (> 15 μD), representing the most efficient storage and flow pathways. Pyrobitumen develops irregular shrinkage pores and microfracture networks during thermal cracking, producing moderate porosity (4–13 %) and permeability (∼ 0.75 μD), with framboidal pyrite stabilizing pore structures against compaction. Fecal pellets, stabilized by early phosphatization through apatite and fluorapatite precipitation, retain isotropic nanoporous frameworks (40–160 nm) with consistent porosity (∼ 5 %) and permeability (∼ 0.8 μD). In contrast, graptolites display poorly connected cortical fibril-aligned nanometer-sized pores (< 20 nm), contributing minimally to storage (porosity <0.6 %) and permeability (< 0.35 μD). Pore size distribution analysis reveals that alginite and pyrobitumen host the largest connected pores, whereas graptolites and fecal pellets are dominated by isolated, ultrafine structures. Diagenetic mineralization emerges as a critical factor in pore preservation, with apatite and pyrite reinforcing nanoporous networks against mechanical collapse. Furthermore, depositional conditions such as water column stratification, nutrient influx, microbial restructuring, and limited degradation of fecal aggregates facilitated OM preservation, leading to the formation of stable nanoporosity critical for long-term gas storage and migration. Integrated FIB-SEM reconstructions and flow simulations establish a hierarchical permeability ranking of alginite > pyrobitumen ≈ fecal pellets > > graptolites, underscoring the significant role of OM type and diagenetic evolution governing shale reservoir quality. These findings highlight that OM composition and its diagenetic trajectory, rather than TOC or maturity alone, are the primary controls on pore netw
{"title":"OM-hosted pore systems in Ordovician Wufeng–Silurian Longmaxi shales in Sichuan Basin SW China: Origin, gas storage, and flow behavior","authors":"Yong Ma , Omid H. Ardakani , Dahua Li , Jianbin Ma , Ningning Zhong , Haiping Huang","doi":"10.1016/j.coal.2025.104897","DOIUrl":"10.1016/j.coal.2025.104897","url":null,"abstract":"<div><div>This study provides an extensive investigation of the origin, morphological evolution, pore structure, and flow behavior of organic matter (OM)-hosted pore systems in the overmature Wufeng–Longmaxi (W–L) shales of the Sichuan Basin, SW China, with implications for shale gas storage and production. Eleven core samples from the Wufeng and Longmaxi formations, spanning a wide range of total organic carbon (TOC) content (0.47–5.48 wt%) but consistently high thermal maturity (EqVRo 3.89–4.20 %), were analyzed using a combination of geochemical analyses, optical microscopy, high-resolution scanning electron microscopy (SEM), three-dimensional focused ion beam-SEM (FIB-SEM) reconstructions, energy dispersive spectroscopy (EDS), and Navier–Stokes-based pore-scale permeability simulations. The OM assemblage comprises pyrobitumen, alginite, graptolites, and fecal pellets, each contributing distinct pore-forming pathways controlled by original ultrastructure, depositional redox conditions, and subsequent diagenetic mineralization. Alginite preserves sponge-like cellular ultrastructures, yielding highly connected macropore networks (> 50 nm), with the highest porosity (> 10 %) and permeability (> 15 μD), representing the most efficient storage and flow pathways. Pyrobitumen develops irregular shrinkage pores and microfracture networks during thermal cracking, producing moderate porosity (4–13 %) and permeability (∼ 0.75 μD), with framboidal pyrite stabilizing pore structures against compaction. Fecal pellets, stabilized by early phosphatization through apatite and fluorapatite precipitation, retain isotropic nanoporous frameworks (40–160 nm) with consistent porosity (∼ 5 %) and permeability (∼ 0.8 μD). In contrast, graptolites display poorly connected cortical fibril-aligned nanometer-sized pores (< 20 nm), contributing minimally to storage (porosity <0.6 %) and permeability (< 0.35 μD). Pore size distribution analysis reveals that alginite and pyrobitumen host the largest connected pores, whereas graptolites and fecal pellets are dominated by isolated, ultrafine structures. Diagenetic mineralization emerges as a critical factor in pore preservation, with apatite and pyrite reinforcing nanoporous networks against mechanical collapse. Furthermore, depositional conditions such as water column stratification, nutrient influx, microbial restructuring, and limited degradation of fecal aggregates facilitated OM preservation, leading to the formation of stable nanoporosity critical for long-term gas storage and migration. Integrated FIB-SEM reconstructions and flow simulations establish a hierarchical permeability ranking of alginite > pyrobitumen ≈ fecal pellets > > graptolites, underscoring the significant role of OM type and diagenetic evolution governing shale reservoir quality. These findings highlight that OM composition and its diagenetic trajectory, rather than TOC or maturity alone, are the primary controls on pore netw","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"312 ","pages":"Article 104897"},"PeriodicalIF":5.7,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145435064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-04DOI: 10.1016/j.coal.2025.104898
Huidi Hao , Bo Jiu , Wenhui Huang , Zhaoguo Wang , Binchao Qin , Linghao Huang
Titanium oxides (predominantly rutile) constitute critical reservoirs of niobium within coal-bearing strata, yet their provenance discrimination remains methodologically challenging. This study establishes a robust rutile provenance discrimination framework for Nb-rich sequences (coal, tonstein, mudstone) in the Ordos Basin through integrated machine learning and rutile trace element geochemistry. Comprehensive analyses via laser Raman spectroscopy (LRS), electron probe microanalysis (EPMA), and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) demonstrate that: LRS identifies rutile as the dominant Ti-phase with minor anatase; trace element mapping reveals V-Nb-Zr-Cr enrichment in coal-hosted rutile versus Si-V-Fe-Nb enrichment in tonstein/mudstone rutile. Geochemical discriminant diagrams show most datapoints within metamorphic fields, with minor magmatic/mineralized signatures; Zr-in-rutile thermometry further confirms the Khondalite Belt (KB) and northern Trans-North China Orogen (TNCO) as primary provenances. Machine learning processing of trace element datasets (Si, Fe, Ti, Cr, Nb, Ta, Zr) using an optimized Random Forest (RF) model identifies the eastern KB and northern TNCO as core source domains. This research not only provides new provenance constraints for critical metal enrichment mechanisms in coal measures but also establishes a transferable machine learning-geochemistry methodology for multi-source tracing in sedimentary basins, offering practical implications for strategic mineral exploration.
氧化钛（主要是金红石）构成了含煤地层中铌的关键储层，但其来源判别在方法上仍然具有挑战性。通过综合机器学习和金红石微量元素地球化学研究，建立了鄂尔多斯盆地富铌层序（煤、铜、泥岩）金红石物源判别框架。通过激光拉曼光谱（LRS）、电子探针显微分析（EPMA）和激光烧蚀-电感耦合等离子体质谱（LA-ICP-MS）的综合分析表明：LRS鉴定金红石为主要钛相，少量锐钛矿；微量元素测图显示煤型金红石中V-Nb-Zr-Cr富集，而东stein/泥岩型金红石中Si-V-Fe-Nb富集。地球化学判别图显示大部分数据点位于变质场内，具有少量岩浆/矿化特征；金红石中锆测温进一步证实孔雀岩带（KB）和北跨华北造山带（TNCO）为主要物源。利用优化的随机森林（Random Forest， RF）模型对微量元素数据集（Si, Fe, Ti, Cr, Nb, Ta, Zr）进行机器学习处理，确定KB东部和TNCO北部为核心源域。本研究不仅为煤系关键金属富集机制提供了新的物源约束条件，而且为沉积盆地多源示踪建立了一种可转移的机器学习-地球化学方法，为战略矿产勘探提供了实际意义。
{"title":"Constraining rutile provenance in Nb-rich coal-bearing strata: An approach integrating trace element geochemistry and machine learning","authors":"Huidi Hao , Bo Jiu , Wenhui Huang , Zhaoguo Wang , Binchao Qin , Linghao Huang","doi":"10.1016/j.coal.2025.104898","DOIUrl":"10.1016/j.coal.2025.104898","url":null,"abstract":"<div><div>Titanium oxides (predominantly rutile) constitute critical reservoirs of niobium within coal-bearing strata, yet their provenance discrimination remains methodologically challenging. This study establishes a robust rutile provenance discrimination framework for Nb-rich sequences (coal, tonstein, mudstone) in the Ordos Basin through integrated machine learning and rutile trace element geochemistry. Comprehensive analyses via laser Raman spectroscopy (LRS), electron probe microanalysis (EPMA), and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) demonstrate that: LRS identifies rutile as the dominant Ti-phase with minor anatase; trace element mapping reveals V-Nb-Zr-Cr enrichment in coal-hosted rutile versus Si-V-Fe-Nb enrichment in tonstein/mudstone rutile. Geochemical discriminant diagrams show most datapoints within metamorphic fields, with minor magmatic/mineralized signatures; Zr-in-rutile thermometry further confirms the Khondalite Belt (KB) and northern Trans-North China Orogen (TNCO) as primary provenances. Machine learning processing of trace element datasets (Si, Fe, Ti, Cr, Nb, Ta, Zr) using an optimized Random Forest (RF) model identifies the eastern KB and northern TNCO as core source domains. This research not only provides new provenance constraints for critical metal enrichment mechanisms in coal measures but also establishes a transferable machine learning-geochemistry methodology for multi-source tracing in sedimentary basins, offering practical implications for strategic mineral exploration.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"311 ","pages":"Article 104898"},"PeriodicalIF":5.7,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145441783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-25DOI: 10.1016/j.coal.2025.104896
Joana Ribeiro , Mónica Ribeiro , Laura Góis , José Erbolato Filho , Magdalena Misz-Kennan , Monika Fabiańska
As the world deal with the global climate and energy crises and energy transition, studies related to coal are still needed because, despite de phasing out of coal, the recognition of the environmental legacy left by fossil fuels is important to identify the influence of its use in the carbon cycle and to meet the main commitments of the European Green Deal. This study aims to identify the fingerprint in soil left by the past activity of Sines thermal power plant (S-TPP, Portugal), which lasted for decades. The multi-analytical approach (petrographic and geochemical techniques) used in the analysis of soil collected in the area surrounding the S-TPP allowed identification and quantification of inorganic and organic contaminants, their source, and allow the understanding of changes in the physic-chemical characteristics of soil induced by the contamination. The results reveal differentiated spatial distribution of changes and contaminants in soils, which are more intense in the south area, attributed to incorporation of contaminants through mobilization and dispersion influenced by predominant winds regime of the region. The incorporation of particles of coal and fly ash in soil enhances the concentration of some potentially toxic elements (As, Ba, Co, Cr, Ni, Se, U, V) beyond national reference values for healthy soil. The contaminants in soil also influence soil granulometric composition, alkalinity, electrical conductivity, total organic carbon and total sulphur. The sources of contaminants in soil are the fly ash and gaseous emission from smoke stacks and coal and fly ash particles mobilized during storage, handling and landfilling operations.
{"title":"The environmental legacy of industrial coal combustion: tracing inorganic and organic contaminants in soils","authors":"Joana Ribeiro , Mónica Ribeiro , Laura Góis , José Erbolato Filho , Magdalena Misz-Kennan , Monika Fabiańska","doi":"10.1016/j.coal.2025.104896","DOIUrl":"10.1016/j.coal.2025.104896","url":null,"abstract":"<div><div>As the world deal with the global climate and energy crises and energy transition, studies related to coal are still needed because, despite de phasing out of coal, the recognition of the environmental legacy left by fossil fuels is important to identify the influence of its use in the carbon cycle and to meet the main commitments of the European Green Deal. This study aims to identify the fingerprint in soil left by the past activity of Sines thermal power plant (S-TPP, Portugal), which lasted for decades. The multi-analytical approach (petrographic and geochemical techniques) used in the analysis of soil collected in the area surrounding the S-TPP allowed identification and quantification of inorganic and organic contaminants, their source, and allow the understanding of changes in the physic-chemical characteristics of soil induced by the contamination. The results reveal differentiated spatial distribution of changes and contaminants in soils, which are more intense in the south area, attributed to incorporation of contaminants through mobilization and dispersion influenced by predominant winds regime of the region. The incorporation of particles of coal and fly ash in soil enhances the concentration of some potentially toxic elements (As, Ba, Co, Cr, Ni, Se, U, V) beyond national reference values for healthy soil. The contaminants in soil also influence soil granulometric composition, alkalinity, electrical conductivity, total organic carbon and total sulphur. The sources of contaminants in soil are the fly ash and gaseous emission from smoke stacks and coal and fly ash particles mobilized during storage, handling and landfilling operations.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"311 ","pages":"Article 104896"},"PeriodicalIF":5.7,"publicationDate":"2025-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145383525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-10DOI: 10.1016/j.coal.2025.104887
Shengqiang Zeng , Jian Wang , Xiugen Fu , Wei Sun , Wangzhong Zhan
Barremian organic-rich black shales are significant source rocks in the eastern Tethyan Qiangtang Basin. Based on petrological, inorganic and organic geochemistry analyses, the black shales are divided into three units from bottom to top. Unit 1 micritic limestones exhibit high total organic carbon (TOC) contents and Type II₂ kerogen, indicating a mixture of marine microalgae and land plants. Unit 2 black shales show the highest TOC contents, predominantly Type II₁ kerogen suggesting marine microalgal source. In contrast, Unit 3 marls have relatively low TOC contents, Type II₂ kerogen, indicating mixed terrestrial and marine OM sources. The black shales show a low organic maturity, and the hydrocarbon generation potential of the black shale and micritic limestone samples is substantially higher than that of the marl samples. Palaeoredox proxies indicate that Unit 1 deposited under dysoxic-anoxic conditions, and Unit 2 formed under anoxic-euxinic conditions, while Unit 3 deposited under oxic-suboxic conditions. Primary productivity proxies reflect high productivity in Units 1 and 2, and low productivity in Unit 3. Rb/K and total sulfur/TOC ratios suggest brackish environment in Units 1 and 2 and brackish or seawater condition in Unit 3. Hydrothermal activity during Unit 2 black shale deposition provided essential nutrients for phytoplankton in the photic zone, leading to high OM production. Upwelling/restriction proxies imply deposition under moderately restricted conditions for Unit 1, strongly restricted conditions for Unit 2, and upwelling/weakly restricted conditions for Unit 3. Palynological analysis indicates a warm, semi-humid to humid temperate climate during deposition of Units 1 and 2, contrasting with a hot, arid to semi-arid climate during Unit 3 marl deposition. OM accumulation of Unit 1 micritic limestone was primarily controlled by stratified dysoxic-anoxic conditions, high primary productivity, warm humid/semi-humid climate, and moderate watermass restriction. For Unit 2 black shale, the main controlling factors were stratified anoxic-euxinic environment, warm humid temperate climate, strongly restricted water condition, and intermittent strong hydrothermal activity. During Unit 3 marl deposition, low primary productivity, an oxygen-rich water environment leading to OM degradation, combined with a hot arid/semi-arid climate, resulted in organic-lean deposition.
{"title":"Organic matter accumulation in Barremian marine black shales of the Qiangtang Basin, China","authors":"Shengqiang Zeng , Jian Wang , Xiugen Fu , Wei Sun , Wangzhong Zhan","doi":"10.1016/j.coal.2025.104887","DOIUrl":"10.1016/j.coal.2025.104887","url":null,"abstract":"<div><div>Barremian organic-rich black shales are significant source rocks in the eastern Tethyan Qiangtang Basin. Based on petrological, inorganic and organic geochemistry analyses, the black shales are divided into three units from bottom to top. Unit 1 micritic limestones exhibit high total organic carbon (TOC) contents and Type II₂ kerogen, indicating a mixture of marine microalgae and land plants. Unit 2 black shales show the highest TOC contents, predominantly Type II₁ kerogen suggesting marine microalgal source. In contrast, Unit 3 marls have relatively low TOC contents, Type II₂ kerogen, indicating mixed terrestrial and marine OM sources. The black shales show a low organic maturity, and the hydrocarbon generation potential of the black shale and micritic limestone samples is substantially higher than that of the marl samples. Palaeoredox proxies indicate that Unit 1 deposited under dysoxic-anoxic conditions, and Unit 2 formed under anoxic-euxinic conditions, while Unit 3 deposited under oxic-suboxic conditions. Primary productivity proxies reflect high productivity in Units 1 and 2, and low productivity in Unit 3. Rb/K and total sulfur/TOC ratios suggest brackish environment in Units 1 and 2 and brackish or seawater condition in Unit 3. Hydrothermal activity during Unit 2 black shale deposition provided essential nutrients for phytoplankton in the photic zone, leading to high OM production. Upwelling/restriction proxies imply deposition under moderately restricted conditions for Unit 1, strongly restricted conditions for Unit 2, and upwelling/weakly restricted conditions for Unit 3. Palynological analysis indicates a warm, semi-humid to humid temperate climate during deposition of Units 1 and 2, contrasting with a hot, arid to semi-arid climate during Unit 3 marl deposition. OM accumulation of Unit 1 micritic limestone was primarily controlled by stratified dysoxic-anoxic conditions, high primary productivity, warm humid/semi-humid climate, and moderate watermass restriction. For Unit 2 black shale, the main controlling factors were stratified anoxic-euxinic environment, warm humid temperate climate, strongly restricted water condition, and intermittent strong hydrothermal activity. During Unit 3 marl deposition, low primary productivity, an oxygen-rich water environment leading to OM degradation, combined with a hot arid/semi-arid climate, resulted in organic-lean deposition.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"311 ","pages":"Article 104887"},"PeriodicalIF":5.7,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145289880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-03DOI: 10.1016/j.coal.2025.104886
Hamed Sanei , Małgorzata Wojtaszek-Kalaitzidi , Niels Hemmingsen Schovsbo , Rasmus Stenshøj , Zhiheng Zhou , Hans-Peter Schmidt , Nikolas Hagemann , David Chiaramonti , Tryfonas Kiaitsis , Arka Rudra , Anna J. Lehner , Robert W. Brown , Sophie Gill , Erica Dorr , Stavros Kalaitzidis , Fariborz Goodarzi , Henrik Ingermann Petersen
The carbon dioxide removal (CDR) potential of biochar is determined by the long-term stability of its biogenic carbon, derived from atmospheric CO₂ fixed by photosynthesis and stabilized in solid form. This stability (carbon permanence) is commonly assessed using decay models to evaluate resistance to re-emission as greenhouse gases. However, these models are limited, as they focus primarily on short-term degradation of labile carbon fractions and are not suited to project the behavior of the highly recalcitrant component of biochar over extended timescales.
Inertinite represents highly aromatized and condensed carbon structures that are geochemically stable over millennia. This paper builds upon the Inertinite Benchmarking (IBRo2) methodology, directly quantifying the stable carbon fraction in biochar rather than relying on modeling. The method combines thermochemical analysis and incident-light microscopy to measure the reactive (labile) component and solid carbonized macerals, respectively. Random reflectance analysis (Ro) provides a representative distribution of carbonization states, with Ro values >2.0 % defining the inertinite fraction after discounting reactive organic carbon. The Ro distribution is processed using kernel density estimation (KDE) and numerical integration to classify inertinite carbon with precision and statistical robustness.
As CDR crediting can be linked to measured inertinite content, statistical validity is essential. A Monte Carlo simulation model evaluates uncertainties from sampling frequency and production variability. Results show that increased sampling reduces uncertainty and lowers the conservative safety margin needed for potential errors. This framework supports a justified safety margin applied to reported inertinite carbon and corresponding CDR values, enabling conservative and robust crediting.
By combining direct quantification of inertinite carbon with probabilistic modeling of uncertainty, the IBRo2 method offers a transparent and rigorous framework for assessing biochar permanence, aligned with emerging international certification and national inventory methodologies.
{"title":"Quantifying inertinite carbon in biochar","authors":"Hamed Sanei , Małgorzata Wojtaszek-Kalaitzidi , Niels Hemmingsen Schovsbo , Rasmus Stenshøj , Zhiheng Zhou , Hans-Peter Schmidt , Nikolas Hagemann , David Chiaramonti , Tryfonas Kiaitsis , Arka Rudra , Anna J. Lehner , Robert W. Brown , Sophie Gill , Erica Dorr , Stavros Kalaitzidis , Fariborz Goodarzi , Henrik Ingermann Petersen","doi":"10.1016/j.coal.2025.104886","DOIUrl":"10.1016/j.coal.2025.104886","url":null,"abstract":"<div><div>The carbon dioxide removal (CDR) potential of biochar is determined by the long-term stability of its biogenic carbon, derived from atmospheric CO₂ fixed by photosynthesis and stabilized in solid form. This stability (carbon permanence) is commonly assessed using decay models to evaluate resistance to re-emission as greenhouse gases. However, these models are limited, as they focus primarily on short-term degradation of labile carbon fractions and are not suited to project the behavior of the highly recalcitrant component of biochar over extended timescales.</div><div>Inertinite represents highly aromatized and condensed carbon structures that are geochemically stable over millennia. This paper builds upon the Inertinite Benchmarking (<em>IBR</em><sub><em>o</em></sub><em>2</em>) methodology, directly quantifying the stable carbon fraction in biochar rather than relying on modeling. The method combines thermochemical analysis and incident-light microscopy to measure the reactive (labile) component and solid carbonized macerals, respectively. Random reflectance analysis (<em>R</em><sub><em>o</em></sub>) provides a representative distribution of carbonization states, with <em>R</em><sub><em>o</em></sub> values >2.0 % defining the inertinite fraction after discounting reactive organic carbon. The <em>R</em><sub><em>o</em></sub> distribution is processed using kernel density estimation (KDE) and numerical integration to classify inertinite carbon with precision and statistical robustness.</div><div>As CDR crediting can be linked to measured inertinite content, statistical validity is essential. A Monte Carlo simulation model evaluates uncertainties from sampling frequency and production variability. Results show that increased sampling reduces uncertainty and lowers the conservative safety margin needed for potential errors. This framework supports a justified safety margin applied to reported inertinite carbon and corresponding CDR values, enabling conservative and robust crediting.</div><div>By combining direct quantification of inertinite carbon with probabilistic modeling of uncertainty, the <em>IBR</em><sub><em>o</em></sub><em>2</em> method offers a transparent and rigorous framework for assessing biochar permanence, aligned with emerging international certification and national inventory methodologies.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"310 ","pages":"Article 104886"},"PeriodicalIF":5.7,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-03DOI: 10.1016/j.coal.2025.104885
Jolanta Kus , Paul C. Hackley
Evaluation of thermal maturity in vitrinite-free or vitrinite-deficient sediments via fluorescence microspectrometry can provide relevant information related to petroleum exploration and thermal history assessment. However, variation in spectral fluorescence properties of alginite macerals with increasing thermal maturity is largely underexplored. Here, authors of this study have applied confocal laser-scanning microscopy (CLSM) in conjunction with fluorescence microspectrometry to a maturity series of marine Upper Devonian Tasmanites algae from the Ohio Shale (Huron Member) and a single sample from the Marcellus Formation of the Appalachian Basin. Spectral fluorescence properties of Tasmanites were evaluated in relation to orientation, measurement location, and the number of measurements per sample, and were compared to published literature. Emission spectra of Tasmanites from continuous wave laser excitation (405 nm) were acquired from sections perpendicular and parallel to bedding and at different positions within individual Tasmanites bodies. The results showed a progressive red-shift in emission maxima (λmax) in a large sample sized maturity series (N = 19), e.g., 493 to 578 nm for the perpendicular section at middle position. Further, blue-shifted apex and mineral-adjacent positions within sections perpendicular to bedding were observed, with the latter being reported here for the first time. While blue-shift at apex positions can be attributed to mechanical deformation-induced reorientation of photoselected fluorophores, the blue-shifted mineral-adjacent positions could result from strain loading and development of a plastic deformation region at the mineral contact zone with Tasmanites. A decrease in standard deviation with increasing number of measured emission maxima is well-observed, and 15 to 20 individual measurements per sample appears sufficient for low standard deviation and coefficient of variance. CLSM-derived thermal maturity parameters indicated that a moderate positive correlation of red/green quotient (Q650/500; R2 = 0.67) with solid bitumen reflectance (BRo in %) exists. For reproducible results, the determination of λmax and Q650/500 should be conducted exclusively in the middle position at perpendicular and parallel sections of the polished whole-rock pellets, where the lowest standard deviation in measurement was observed. These results strengthen the suitability and relevance of the CLSM technique in thermal maturity studies of dispersed organic matter (DOM) and contribute to the standardization of fluorescence microspectrometry methods in organic petrology investigation.
{"title":"Confocal laser-scanning microscopy (CLSM)-based thermal maturity of Tasmanites and progress in standardization of fluorescence microspectrometry","authors":"Jolanta Kus , Paul C. Hackley","doi":"10.1016/j.coal.2025.104885","DOIUrl":"10.1016/j.coal.2025.104885","url":null,"abstract":"<div><div>Evaluation of thermal maturity in vitrinite-free or vitrinite-deficient sediments via fluorescence microspectrometry can provide relevant information related to petroleum exploration and thermal history assessment. However, variation in spectral fluorescence properties of alginite macerals with increasing thermal maturity is largely underexplored. Here, authors of this study have applied confocal laser-scanning microscopy (CLSM) in conjunction with fluorescence microspectrometry to a maturity series of marine Upper Devonian <em>Tasmanites</em> algae from the Ohio Shale (Huron Member) and a single sample from the Marcellus Formation of the Appalachian Basin. Spectral fluorescence properties of <em>Tasmanites</em> were evaluated in relation to orientation, measurement location, and the number of measurements per sample, and were compared to published literature. Emission spectra of <em>Tasmanites</em> from continuous wave laser excitation (405 nm) were acquired from sections perpendicular and parallel to bedding and at different positions within individual <em>Tasmanites</em> bodies. The results showed a progressive red-shift in emission maxima (λ<sub>max</sub>) in a large sample sized maturity series (<em>N</em> = 19), e.g., 493 to 578 nm for the perpendicular section at middle position. Further, blue-shifted apex and mineral-adjacent positions within sections perpendicular to bedding were observed, with the latter being reported here for the first time. While blue-shift at apex positions can be attributed to mechanical deformation-induced reorientation of photoselected fluorophores, the blue-shifted mineral-adjacent positions could result from strain loading and development of a plastic deformation region at the mineral contact zone with <em>Tasmanites</em>. A decrease in standard deviation with increasing number of measured emission maxima is well-observed, and 15 to 20 individual measurements per sample appears sufficient for low standard deviation and coefficient of variance. CLSM-derived thermal maturity parameters indicated that a moderate positive correlation of red/green quotient (Q<sub>650/500</sub>; R<sup>2</sup> = 0.67) with solid bitumen reflectance (BR<sub>o</sub> in %) exists. For reproducible results, the determination of λ<sub>max</sub> and Q<sub>650/500</sub> should be conducted exclusively in the middle position at perpendicular and parallel sections of the polished whole-rock pellets, where the lowest standard deviation in measurement was observed. These results strengthen the suitability and relevance of the CLSM technique in thermal maturity studies of dispersed organic matter (DOM) and contribute to the standardization of fluorescence microspectrometry methods in organic petrology investigation.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"310 ","pages":"Article 104885"},"PeriodicalIF":5.7,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-23DOI: 10.1016/j.coal.2025.104884
Jiuqing Li , Yong Qin , Jian Shen , Yilin Chen , Geng Li , Peipei Zhu
Coal-based graphite deposits developed in Lutang, Hunan Province, China, provide an opportunity to investigate the petrographic characteristics of graphitic carbon. Optical microscopy and microphotometry were employed to observe the morphology, microstructure, occurrence and reflectance of graphitic carbon and thus classify its type. The results indicated that the evolutionary stage of the coal-based graphite reached the semi-graphite to graphite phase, and five types of graphitic carbon, namely, matrix graphite, granular graphite, needle graphite, flake graphite and pyrolytic carbon, were identified. The maximum reflectances of different types of graphitic carbon vary, indicating a differential evolutionary stage. However, the bireflectance progressively increases through the sequence of needle graphite, pyrolytic carbon and flake graphite, reflecting enhanced structural ordering of basic structural units. In terms of their particle size and reflectance characteristics, granular graphite, needle graphite, pyrolytic carbon, and flake graphite exhibit phanerocrystalline structures, whereas matrix graphite belongs to the cryptocrystalline graphite category. Three primary mechanisms for the origin and formation of graphitic carbon were proposed: in situ solid-phase transformation, liquid-phase crystallization, and vapor-phase deposition. Flake graphite serves as the ideal material for measuring reflectance in coal-based graphite, with its reflectance value acting as an indicator of evolutionary maturity.
{"title":"Petrolographic characteristics of graphitic carbon in coal-based graphite: Implications for the applicability of reflectance","authors":"Jiuqing Li , Yong Qin , Jian Shen , Yilin Chen , Geng Li , Peipei Zhu","doi":"10.1016/j.coal.2025.104884","DOIUrl":"10.1016/j.coal.2025.104884","url":null,"abstract":"<div><div>Coal-based graphite deposits developed in Lutang, Hunan Province, China, provide an opportunity to investigate the petrographic characteristics of graphitic carbon. Optical microscopy and microphotometry were employed to observe the morphology, microstructure, occurrence and reflectance of graphitic carbon and thus classify its type. The results indicated that the evolutionary stage of the coal-based graphite reached the semi-graphite to graphite phase, and five types of graphitic carbon, namely, matrix graphite, granular graphite, needle graphite, flake graphite and pyrolytic carbon, were identified. The maximum reflectances of different types of graphitic carbon vary, indicating a differential evolutionary stage. However, the bireflectance progressively increases through the sequence of needle graphite, pyrolytic carbon and flake graphite, reflecting enhanced structural ordering of basic structural units. In terms of their particle size and reflectance characteristics, granular graphite, needle graphite, pyrolytic carbon, and flake graphite exhibit phanerocrystalline structures, whereas matrix graphite belongs to the cryptocrystalline graphite category. Three primary mechanisms for the origin and formation of graphitic carbon were proposed: in situ solid-phase transformation, liquid-phase crystallization, and vapor-phase deposition. Flake graphite serves as the ideal material for measuring reflectance in coal-based graphite, with its reflectance value acting as an indicator of evolutionary maturity.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"310 ","pages":"Article 104884"},"PeriodicalIF":5.7,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-16DOI: 10.1016/j.coal.2025.104883
Jin Wu , Qingyong Luo , Ningning Zhong , Fariborz Goodarzi , Yang Bai , Václav Suchý , Meijun Li , Lipeng Yao , Imran Khan , Ye Zhang , Haoran Wang , Haixu Liu , Yinghang Tang
Graptolites are widely presented in the Ordovician–Silurian Wufeng–Longmaxi Formations and other Lower Paleozoic marine shales throughout the world, and their reflectance is regarded as an effective index for the thermal maturity assessment of the graptolite-bearing shales devoid of vitrinite. Graptolites display distinct optically biaxial features, and the optical characteristics and reflectance of graptolites reveal significant differences depending on orientation of respective graptolite fragments relative to the bedding planes. However, specific studies on these optical discrepancies remains limited, resulting in confusion and/or substantial errors in thermal maturity assessment of graptolite-bearing shales. In this study, the organic petrological method was employed to compare the optical characteristics of graptolites in sections parallel and perpendicular to the bedding. Graptolites and in-source solid bitumen (SB) are the dominant organic components in the Alum and Wufeng–Longmaxi graptolite-bearing shales, and the liptinites are only detected in low maturity samples. In the studied sediments, both non-granular and granular graptolites were identified in abundance, but non-granular graptolites, which exhibit higher reflectance and stronger anisotropy than granular graptolites, were the predominant species. The intense positive correlations between the mean random reflectance (GRo) and true maximum reflectance (Rmax) and bireflectance of non-granular graptolites indicate their increasing anisotropy with maturation. Rmax values in sections parallel to the bedding are slightly lower than or equal to those in sections perpendicular to the bedding, and the mean maximum reflectance (max), the intermediate reflectance (Rint), and bireflectance are lower than those in sections perpendicular to the bedding. GRo values in sections parallel to the bedding display a strong positive correlation with GRo in sections perpendicular to the bedding, and the former are higher than the latter. GRo exhibits stronger positive correlations with Rmax, max, and bireflectance in sections perpendicular to the bedding than those in sections parallel to the bedding, revealing the stronger anisotropy of non-granular graptolites in sections perpendicular to the bedding. According to the reflectance discrepancies of non-granular graptolites in sections parallel and perpendicular to the bedding, several equivalent equations are proposed to evaluate the thermal maturity of Ordovician–Silurian graptolites-bearing sediments.
{"title":"The organic petrology of graptolites in sections parallel and perpendicular to the bedding: Implication for thermal maturity evaluation","authors":"Jin Wu , Qingyong Luo , Ningning Zhong , Fariborz Goodarzi , Yang Bai , Václav Suchý , Meijun Li , Lipeng Yao , Imran Khan , Ye Zhang , Haoran Wang , Haixu Liu , Yinghang Tang","doi":"10.1016/j.coal.2025.104883","DOIUrl":"10.1016/j.coal.2025.104883","url":null,"abstract":"<div><div>Graptolites are widely presented in the Ordovician–Silurian Wufeng–Longmaxi Formations and other Lower Paleozoic marine shales throughout the world, and their reflectance is regarded as an effective index for the thermal maturity assessment of the graptolite-bearing shales devoid of vitrinite. Graptolites display distinct optically biaxial features, and the optical characteristics and reflectance of graptolites reveal significant differences depending on orientation of respective graptolite fragments relative to the bedding planes. However, specific studies on these optical discrepancies remains limited, resulting in confusion and/or substantial errors in thermal maturity assessment of graptolite-bearing shales. In this study, the organic petrological method was employed to compare the optical characteristics of graptolites in sections parallel and perpendicular to the bedding. Graptolites and in-source solid bitumen (SB) are the dominant organic components in the Alum and Wufeng–Longmaxi graptolite-bearing shales, and the liptinites are only detected in low maturity samples. In the studied sediments, both non-granular and granular graptolites were identified in abundance, but non-granular graptolites, which exhibit higher reflectance and stronger anisotropy than granular graptolites, were the predominant species. The intense positive correlations between the mean random reflectance (GR<sub>o</sub>) and true maximum reflectance (R<sub>max</sub>) and bireflectance of non-granular graptolites indicate their increasing anisotropy with maturation. R<sub>max</sub> values in sections parallel to the bedding are slightly lower than or equal to those in sections perpendicular to the bedding, and the mean maximum reflectance (<span><math><mover><mi>R</mi><mo>¯</mo></mover></math></span><sub>max</sub>), the intermediate reflectance (R<sub>int</sub>), and bireflectance are lower than those in sections perpendicular to the bedding. GR<sub>o</sub> values in sections parallel to the bedding display a strong positive correlation with GR<sub>o</sub> in sections perpendicular to the bedding, and the former are higher than the latter. GR<sub>o</sub> exhibits stronger positive correlations with R<sub>max</sub>, <span><math><mover><mi>R</mi><mo>¯</mo></mover></math></span><sub>max</sub>, and bireflectance in sections perpendicular to the bedding than those in sections parallel to the bedding, revealing the stronger anisotropy of non-granular graptolites in sections perpendicular to the bedding. According to the reflectance discrepancies of non-granular graptolites in sections parallel and perpendicular to the bedding, several equivalent equations are proposed to evaluate the thermal maturity of Ordovician–Silurian graptolites-bearing sediments.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"310 ","pages":"Article 104883"},"PeriodicalIF":5.7,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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