The study aimed to develop a customized Data Governance Maturity Model (DGMM) for the Ministry of Defence (MoD) in Kenya to address data governance challenges in military settings. Current frameworks lack specific req...The study aimed to develop a customized Data Governance Maturity Model (DGMM) for the Ministry of Defence (MoD) in Kenya to address data governance challenges in military settings. Current frameworks lack specific requirements for the defence industry. The model uses Key Performance Indicators (KPIs) to enhance data governance procedures. Design Science Research guided the study, using qualitative and quantitative methods to gather data from MoD personnel. Major deficiencies were found in data integration, quality control, and adherence to data security regulations. The DGMM helps the MOD improve personnel, procedures, technology, and organizational elements related to data management. The model was tested against ISO/IEC 38500 and recommended for use in other government sectors with similar data governance issues. The DGMM has the potential to enhance data management efficiency, security, and compliance in the MOD and guide further research in military data governance.展开更多
This study explores the relationship between corporate environmental,social,and governance(ESG)disagreements and corporate debt maturity.By examining panel samples from Chinese non-financial listed companies covering ...This study explores the relationship between corporate environmental,social,and governance(ESG)disagreements and corporate debt maturity.By examining panel samples from Chinese non-financial listed companies covering 2007 to 2020,we find that ESG disagreements negatively influence corporate debt maturity.Even after conducting a series of robustness tests and addressing endogeneity concerns,the adverse effects of ESG disagreements persisted.A heterogeneity analysis shows that this negative impact is more significant for non-state-owned enterprises,small enterprises,enterprises with high capital intensity,enterprises with low analyst attention,and enterprises in high-tech industries.Through a mechanism analysis,we discovered that ESG disagreements can lead to information asymmetry and heightened default risk,subsequently affecting the maturity of corporate debt.Further analysis confirms that the negative impact of ESG on the debt structure inhibits long-term investment and exacerbates the mismatch between investment and financing terms.展开更多
In addition to the organic matter type,abundance,thermal maturity,and shale reservoir space,the preservation conditions of source rocks play a key factor in affecting the quantity and quality of retained hydrocarbons ...In addition to the organic matter type,abundance,thermal maturity,and shale reservoir space,the preservation conditions of source rocks play a key factor in affecting the quantity and quality of retained hydrocarbons in source rocks of lacustrine shale,yet this aspect has received little attention.This paper,based on the case analysis,explores how preservation conditions influence the enrichment of mobile hydrocarbons in shale oil.Research showns that good preservation conditions play three key roles.(1)Ensure the retention of sufficient light hydrocarbons(C_(1)–C_(13)),medium hydrocarbons(C_(14)–C_(25))and small molecular aromatics(including 1–2 benzene rings)in the formation,which enhances the fluidity and flow of shale oil;(2)Maintain a high energy field(abnormally high pressure),thus facilitating the maximum outflow of shale oil;(3)Ensure that the retained hydrocarbons have the miscible flow condition of multi-component hydrocarbons(light hydrocarbons,medium hydrocarbons,heavy hydrocarbons,and heteroatomic compounds),so that the heavy hydrocarbons(C_(25+))and heavy components(non-hydrocarbons and asphaltenes)have improved fluidity and maximum flow capacity.In conclusion,in addition to the advantages of organic matter type,abundance,thermal maturity,and reservoir space,good preservation conditions of shale layers are essential for the formation of economically viable shale oil reservoirs,which should be incorporated into the evaluation criteria of shale oil-rich areas/segments and considered a necessary factor when selecting favorable exploration targets.展开更多
Savannah,Ga.,May 20,2025-Gulfstream Aerospace Corp.today announced the 50th customer delivery of the Gulfstream G700.The aircraft was outfitted at Gulfstream's Savannah completions center.Since entering service in...Savannah,Ga.,May 20,2025-Gulfstream Aerospace Corp.today announced the 50th customer delivery of the Gulfstream G700.The aircraft was outfitted at Gulfstream's Savannah completions center.Since entering service in April 2024,the G700 operates globally,and the fleet has accumulated more than 11,700 flight hours.展开更多
Background Boars undergo physiological and biochemical changes in semen composition as they grow from puberty to sexual maturity.However,comprehensive metabolomic profiles of boar semen remain uncharacterised.Understa...Background Boars undergo physiological and biochemical changes in semen composition as they grow from puberty to sexual maturity.However,comprehensive metabolomic profiles of boar semen remain uncharacterised.Understanding metabolic alterations in semen during this period is important for optimising reproductive performance in breeding programs.The aim of this study was to characterise the semen metabolome as boars mature,utilising an untargeted metabolomic approach.Semen samples were collected from 15 Duroc boars at three developmental ages:~7 months,8.5 months,and 10 months.Sperm and seminal plasma were separated and analysed by hydrophilic interaction and reversed-phase liquid chromatography coupled with mass spectrometry to capture a wide range of metabolites.Results We identified a total of 4,491 features in boar semen,annotating 92 distinct metabolites.Amino acids,peptides and analogues constituted the most abundant components,followed by fatty acid esters.Principal component analysis(PCA)and partial least squares discriminant analysis(PLS-DA)showed a clear separation between metabolomic profiles by age groups.PERMANOVA analysis of PCA scores confirmed statistically significant differences(P<0.05)between younger(7 months)and more mature boars(8.5 months and 10 months).Pathway analysis identified porphyrin metabolism,taurine and hypotaurine metabolism,and glycerolipid metabolism as significantly enriched pathways in sperm,while glutathione and nitrogen metabolism were prominently enriched in seminal plasma.Using linear modelling,partial Spearman correlation and random forest analyses,we identified homoisovanillic acid as a key metabolite discriminating age groups in both sperm and seminal plasma.Additionally,L-glutamic acid,decanoyl-L-carnitine and N-(1,3-Thiazol-2-yl)benzenesulfonamide emerged as important sperm metabolites,while glyceric acid,myo-inositol,glycerophosphocholine,and several other compounds were identified as critical seminal plasma metabolites.Conclusion This study provides a detailed characterisation of metabolic changes in Duroc boar semen during the transition from puberty to sexual maturity.Our findings enhance the understanding of reproductive development and could inform strategies to assess sexual maturity in breeding programs.展开更多
Organic matter(OM)is the primary gas occurrence carrier in shale reservoirs due to their abundant nanopores.To reveal the OM pore structure,adsorption capacity and evolution during thermal maturation,this study collec...Organic matter(OM)is the primary gas occurrence carrier in shale reservoirs due to their abundant nanopores.To reveal the OM pore structure,adsorption capacity and evolution during thermal maturation,this study collected data from samples spanning the entire evolution stage,from immature to over-mature.Scanning Electron Microscope(SEM)observation and low temperature gases adsorption experiments were used to qualitatively-semi-quantitatively and quantitatively analyze OM pore structure evolution,and CH_(4) isothermal adsorption experiments were used to reveal the adsorption capacity evolution.Then,the influence and mechanism of matu rity and hydrocarbon generation on pore development and adsorption capacity were quantitatively reviewed based on the experimental data.The results show that OM pores are poorly developed in the immature stage due to weak hydrocarbon generation,although micro-fractures are occasionally found at the edges of OM particles.In the low maturity stage,OM pores are partially developed due to liquid hydrocarbon generation,with liquid hydrocarbons also filling some OM pores.The contribution of total organic carbon content(TOC)to adsorption extent is not significant in these two stages.From high to high-over maturity stages,massive gaseous hydrocarbons are generated,significantly improving the surface porosity of OM.Clear positive linear correlations are observed between TOC and adsorption amount.However,the development of OM pores significantly declines when thermal maturity(R_(o))exceeds 3.5%due to excessive aromatization.The accuracy of research on the evolution of pore structure and adsorption capacity is limited by several factors:(ⅰ)errors caused by sample specification,calculation processes,parameter settings,and kerogen models in isothermal adsorption experiments and molecular simulations;(ⅱ)difficulty in achieving control variables due to the strong heterogeneity of natural maturation shale samples;and(ⅲ)the need to enhance compatibility between thermal simulation experiments and natural thermal evolution.Therefore,isothermal adsorption experiments on bulk shale and molecular simulations of intact shale model are necessary,taking into account the dynamic temperature and pressure of in-situ reservoirs.Moreover,shale samples with varying maturity,influenced by their distance from the paleo-thermal source,may provide significant verification for thermal simulation experiments.展开更多
Light hydrocarbons(LHs)are key components of petroleum,and the carbon isotopes composition(δ^(13)C)of individual LHs contains a wealth of geochemical information.Forty-four oil samples from five different basins were...Light hydrocarbons(LHs)are key components of petroleum,and the carbon isotopes composition(δ^(13)C)of individual LHs contains a wealth of geochemical information.Forty-four oil samples from five different basins were analyzed using gas chromatography(GC),gas chromatography-mass spectrometry(GC–MS),and gas chromatography-isotope ratio mass spectrometry(GC-IRMS).Theδ^(13)C values of forty-three LHs were recognized and determined by comparing the GC and GC-IRMS methods.The results revealed significant differences inδ^(13)C distribution characteristics among different LH compounds.Theδ^(13)C variation of individual LHs in iso-paraffins showed the widest range,followed by cycloalkanes and aromatics,whereas theδ^(13)C variation in n-paraffins showed the narrowest range.Theδ^(13)C values of most individual LHs are primarily affected by the source facies and thermal evolution.Among them,c-1,3-dimethylcyclohexane(c-1,3DMCH)is mainly sourced from higher plants but may also form through abiotic mechanisms such as catalysis or cyclization.Theδ^(13)C values of c-1,3DMCH(δ^(13)Cc-1,3DMCH)primarily exhibit parental genetic characteristics,enabling effective distinction of oil from different source facies.Specifically,theδ^(13)Cc-1,3DMCH in marine oils,lacustrine oils,terrigenous oils,and coal-formed oils are<–22‰,from–22‰to−20.2‰,from−20.2‰to−18.4‰,and>−18.4‰,respectively.Moreover,maturity is the primary controlling factor forδ^(13)C values of 3MC7(δ^(13)C3MC7,3MC7:3-methylheptane),while the source facies serve as a secondary influence.The plot ofδ^(13)Cc-1,3DMCH andδ^(13)C3MC7 was introduced to classify source facies.Asδ^(13)Cc-1,3DMCH andδ^(13)C3MC7 increase,the source facies transits from marine to lacustrine,then terrigenous,and finally coal facies.Additionally,increasingδ^(13)C3MC7 indicates a relative increase in maturity.Therefore,theδ^(13)Cc-1,3DMCH vs.δ^(13)C3MC7 plot serves as an effective tool for distinguishing source facies and assessing relative maturity.展开更多
In the era of global tourism and creative economies,digital technology maturity has emerged as a critical factor for the sustainable development of small and medium enterprises(SMEs)in Indonesia.This research is imple...In the era of global tourism and creative economies,digital technology maturity has emerged as a critical factor for the sustainable development of small and medium enterprises(SMEs)in Indonesia.This research is implemented to find out current digital technology maturity levels among SMEs in the subdistrict of Cangkringan,district of Sleman,Yogyakarta,Indonesia,highlighting their role in fostering sustainable tourism and creative economic growth.Using a mixed-method approach,the research combines qualitative insights from in-depth interviews with three local government representatives and Focus Group Discussion with 15 SMEs in the area.Additionally,a quantitative analysis of SMEs across various sectors,including crafts and culinary services,supports the study’s conclusions.The finding reveals a significant gap between government’s training programs and the digital literacy of SMEs as well as a lack of affordable technological resources which could impede the full realization of digital benefits.Strengthening digital technology maturity among SMEs is essential for enhancing their competitiveness and long-term sustainability,yielding both financial and non-financial benefits.This also contributes to find out digital literacy gaps,impact on competitiveness and sustainability,policy and stakeholder recommendations,and government action.These insights offer valuable guidance for policymakers and stakeholders striving to support the digital transformation of SMEs in similar settings.The study also sheds light on digital literacy gaps,their impact on competitiveness and offers policy recommendations for government and stakeholders to address these challenges such as through government and community collaboration.展开更多
Thermal maturation and petroleum generation modeling of shales is essential for suc- cessful exploration and exploitation of conventional and unconventional oil and gas plays. For basin- wide unconventional resource p...Thermal maturation and petroleum generation modeling of shales is essential for suc- cessful exploration and exploitation of conventional and unconventional oil and gas plays. For basin- wide unconventional resource plays such modeling, when well calibrated with direct maturity meas- urements from wells, can characterize and locate production sweet spots for oil, wet gas and dry gas. The transformation of kerogen to petroleum is associated with many chemical reactions, but models typically focus on first-order reactions with rates determined by the Arrhenius Equation. A miscon- ception has been perpetuated for many years that accurate thermal maturity modeling of vitrinite re- flectance using the Arrhenius Equation and a single activation energy, to derive a time-temperature index （~TTIARa）, as proposed by Wood （1988）, is flawed. This claim was initially made by Sweeney and Burnham （1990） in promoting their ＂EasyRo＂ method, and repeated by others. This paper dem- onstrates through detailed multi-dimensional burial and thermal modeling and direct comparison of the ~TTIARR and ＂EasyRo＂ methods that this is not the case. The ~TTIA^R method not only provides a very useful and sensitive maturity index, it can reproduce the calculated vitrinite reflectance values derived from models based on multiple activation energies （e.g., ＂EasyRo＂）. Through simple expres- sions the ~TTIAaa method can also provide oil and gas transformation factors that can be flexibly scaled and calibrated to match the oil, wet gas and dry gas generation windows. This is achieved in a more-computationally-efficient, flexible and transparent way by the ~TTIARR method than the ＂EasyRo＂ method. Analysis indicates that the ＂EasyRo＂ method, using twenty activation energies and a constant frequency factor, generates reaction rates and transformation factors that do not realisti- cally model observed kerogen behaviour and transformation factors over geologic time scales.展开更多
Chiromantes dehaani, as one of the dominant species in intertidal regions of the Yangtze estuary, plays an important role in the ecosystem. To study allometry and maturity in different phases, morphological data had b...Chiromantes dehaani, as one of the dominant species in intertidal regions of the Yangtze estuary, plays an important role in the ecosystem. To study allometry and maturity in different phases, morphological data had been collected from October in 2009 to September in 2010. Morphologic data such as carapace, cheliped and abdomen were processed by cluster and piecewise linear regression analyses. Discriminat function and logistic curves were built to determine different phases and sizes at 50% maturity, respectively. The results showed that the cheliped width in males and abdomen width in females both presented obvious allometry. The sizes of 50% morphometric maturity occurred at 16.36 mm and 18.22 mm carapace width in males and females, respectively. The life history of males could be divided into three phases while that of females only had two phases according to different growth rates. A significant change in allometry of juvenile males with a break point was detected at 11.78 mm carapace width; carapace width of juvenile and adult females overlapped in a range of 13.04 - 18.64 mm. The crabs attained 50% physiological maturity at the size of 17.50 mm and 17.20 mm for females and males, respectively. For male, the size of morphological maturity was larger than that of physiological maturity, which was opposite to that of female.展开更多
[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable d...[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable development. [Methods] A three-year field positioning experiment was carried out. In the first year, five differ- ent levels （0, 2.81, 5.61, 8.42, 11.23 t/hm~） of Astragalus sinicus ploughed at matu- rity stage were designed. And in the next two years, the amounts of ploughed As- tragalus sinicus at maturity stage were based on the natural growth amounts of As- tragalus sinicus at maturity stage of the former year in each plot field. The yields of Astragalus sinicus at maturity stage were estimated and ploughed directly before rice transplanting. Rice yield, soil nutrients, biological properties and water-stable aggre- gates of paddy fields were measured as well. [Results] The effective panicles and rice yields increased significantly after ploughing Astragalus sinicus at maturity stage. Meanwhile, the organic acid content in paddy field increased and the activities of soil phosphatases, invertase and catalase were higher. The soil dissolved organic carbon also increased with the increasing application of green manure. However, excess amount of green manure inhibited the soil microbial biomass carbon content. The macro aggregates and micro aggregates gathered to middle aggregates. [Conclusion] As green manure, the use of Astragalus sinicus at maturity stage could improve soil physiochemical and biological properties, improve soil fertility and increase rice yield significantly. But the ploughing amount of Astragalus sinicus at maturity stage before rice transplanting should be less than 8.42 t/hm2 （dry weight.展开更多
In this study, peaches of cv. ＇Sui Yuan＇ with different maturities were treated with 0.05 mM sodium nitroprusside （SNP）, a nitric oxide donor, for 5 min, at 28℃, and then stored at 0-1.5℃ for 30 days. Untreated ...In this study, peaches of cv. ＇Sui Yuan＇ with different maturities were treated with 0.05 mM sodium nitroprusside （SNP）, a nitric oxide donor, for 5 min, at 28℃, and then stored at 0-1.5℃ for 30 days. Untreated fruits stored under the same conditions were used as control fruits in the experiment. The browning level, activities of polyphenol oxidase （PPO）, peroxydase （POD） and superoxide dismutase （SOD）, and quality parameters （firmness, titratable acid, total soluble solids and total sugar） were analyzed. The results showed that the firmness of SNP-treated fruit at different stage of maturity were higher than that of the control fruit after storage for 30 days. However, no significant effect was found on total soluble solid content. The titratable acid content of low maturity fruit was higher in SNP-treated one than that of the control, but the titratable acid content of high maturity fruit treated by SNP was lower than that of the control on 10th and 30th day. In addition, the combination of SNP treatment and high maturity resulted in higher activities of SOD, lower activity of PPO and POD, lower browning level. Therefore, the combination of high maturity and SNP treatment might be a useful method to well maintain honey peach fruit quality during cold storage.展开更多
Based on the concept of debt duration,this paper proposes the elasticity of cash flow.Then,the debt maturity structure in project financing is discussed.The results show that in the project financing structure,the deb...Based on the concept of debt duration,this paper proposes the elasticity of cash flow.Then,the debt maturity structure in project financing is discussed.The results show that in the project financing structure,the debt maturity structure is closely related with debt capacity.Higher debt ratio requires short term debt,and vise versa.展开更多
Emma is one of the most successful novels by Jane Austen.This thesis analyzed the background of its heroine Emma’s growth background,her growth from conceit,snobbery,domination to maturity,and the causes of her chara...Emma is one of the most successful novels by Jane Austen.This thesis analyzed the background of its heroine Emma’s growth background,her growth from conceit,snobbery,domination to maturity,and the causes of her character transformation.Her psychological growth process from innocence to maturity demonstrates women’s growth and progress in the early 19th cen tury,and inspires modern women to gradually improve in personality and better present their charms of maturity.展开更多
CuItivars K326, Yunyan 87 and Guiyan 4 were used to investigate the curing characteristics and suitabIe harvest maturity of fresh fIue-cured tobacco Ieaves in Ankang tobacco growing areas. ResuIts indicated that the w...CuItivars K326, Yunyan 87 and Guiyan 4 were used to investigate the curing characteristics and suitabIe harvest maturity of fresh fIue-cured tobacco Ieaves in Ankang tobacco growing areas. ResuIts indicated that the water Ioss of K326 was sIow,and the Ieaves were resistant to curing and reIative easiIy to cure. The water Ioss of Yunyan 87 and Guiyan 4 were quick, and the Ieaves with normal resistance to curing were reIative difficuIt to cure. For Guiyan 4, the shrinkage of CM1 maturity was the Iargest. For K326 and Yunyan 87, the shrinkages of CM2 maturity were the Iargest whiIe the shrinkage of CM1 maturity was the Iowest, but the difference did not reach statistical significance. The proportion of top-middIe-grade tobacco Ieaves and average price for K326 were the highest with XM2, CM2 and BM2 maturity, and for Yunyan 87 were XM1, CM3 and BM2 maturity. For K326, Ieaves with XM2, CM2 and BM2 maturity showed the balanced chemical components and the best smoking quality.展开更多
The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues （VR） collected from markets of Tunis City with ...The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues （VR） collected from markets of Tunis City with residues of Posidonia oceanica （PoR）, collected from Tunis beaches. The accumulation in beaches （as well as their removal） constitutes a serious environmental problem in all Mediterranean countries particularly in Tunisia. Aerobic-thermophilic composting is the most reasonable way to profit highly-valuable content of organic matter in these wastes for agricultural purposes. The physical, chemical, and biological parameters were monitored during composting over 150 d. The most appropriate parameters were selected to establish the maturity degree. The main result of this research was the deduction of the following maturity criterion： （a） C/N ratio 〈 15; （b） NH4^＋-N 〈 400 mg/kg; （c） CO2-C 〈 2000 mg CO2-C/kg; （d） dehydrogenase activity 〈 1 mg TPF/g dry matter; （e） germination index （GI） 〉 80%. These five parameters, considered jointly are indicative of a high maturity degree and thus of a high-quality organic amendment which employed in a rational way, may improve soil fertility and soil quality. The mature compost was relatively rich in N （13.0 g/kg）, P （4.74 g/kg） and MgO （15.80 g/kg）. Thus composting definitively constitutes the most optimal option to exploit these wastes.展开更多
Organic matter(OM)nanopores developed in transitional facies shales,i.e.,the Upper Permian Longtan and Dalong Formations in the Yangtze Platform,China,were investigated to determine the corre-sponding influence of the...Organic matter(OM)nanopores developed in transitional facies shales,i.e.,the Upper Permian Longtan and Dalong Formations in the Yangtze Platform,China,were investigated to determine the corre-sponding influence of thermal maturity and OM types within the geological conditions.A suite of 16 core samples were taken from Type-Ⅲ Longtan shales and Type-Ⅱ Dalong shales from two wells covering a ma-turity(Ro,vitrinite reflectance)ranging from 1.22%to 1.43%and 2.62%to 2.97%,respectively.Integrated analysis of the shale samples was carried out,including field-emission scanning electron microscopy(FESEM),low-pressure N2 and CO2 adsorption,high-pressure CH4 adsorption,and mercury intrusion capillary pressure(MICP)analysis.The fluid inclusions of liquid and gas hydrocarbons trapped in calcite vein samples in Dalong shales of two wells were studied using laser Raman and fluorescence spectroscopy.FE-SEM images indicated that OM pores in different formations varied substantially in terms of shape,size,and distribution density.OM pores in Type-Ⅱ Dalong shales of Well XY1 were mainly micropore,sparsely distributed in the gas-prone kerogen with a spot-like and irregular shape,while bitumen rarely developed observable pores.In contrast,the morphology of OM pores in Type-Ⅲ Longtan shales were significantly different,which was due to differences in the OM type.The primary OM pores in some terrestrial woody debris in Longtan shales had a relatively larger pore diameter,ranging from hundreds of nanometers to a few micrometers and were al-most all rounded in shape,which might be one of the factors contributing to larger pore volume and gas adsorption capacity than Dalong shales of Well XY1.Comparing Dalong shales of Well XY1 with relatively lower thermal maturity,there were abundant spongy-like pores,densely developed in the pyrobitumen in Type-Ⅱ Dalong shales of Well EY1,with an irregular shape and diameter ranging from several to hundreds of nanometers.Many blue fluorescent oil inclusions and a small number of CH4 inclusions mixed with C2H6 could be observed within calcite veins in Dalong shales of Well XY1,whereas only CH4 inclusions could be identified within calcite veins in Dalong shales of Well EJ1.Therefore,thermal maturity not only controlled the type of hydrocarbons generated,but also makes a significant contribution to the formation of OM pores,resulting in larger pore volumes and adsorption capacity of Type-Ⅱ shale samples in the dry gas window.展开更多
Aromatic fractions of 140 oils and condensates that originated from different types of source rocks （marine shale,terrestrial shale and marine carbonate） were analyzed using gas chromatographymass spectrometry （GC...Aromatic fractions of 140 oils and condensates that originated from different types of source rocks （marine shale,terrestrial shale and marine carbonate） were analyzed using gas chromatographymass spectrometry （GC-MS） to investigate the relative distributions of methylated dibenzothiophenes with respect to thermal maturity.The positions of methyl groups of trimethyldibenzothiophene isomers （TMDBTs） including those used in the definition of maturity indicator TMDBT index in previous studies were firmly identified by co-elution of internal standards in GC-MS analysis and by comparing with reported retention indices.A new maturity ratio related to dimethyldibenzothiophenes （DMDBTs） is proposed on the basis of the differences in thermodynamic stability among different DMDBT isomers.Another maturity index （TMDBT-I2） based on TMDBTs is also suggested on the basis of our empirical observations and presumed thermodynamic stability of TMDBT isomers.These two newly proposed （2,6 ＋ 3,6）-/1,4-DMDBT ratio and TMDBT-I2 correlate well with MDR （4-/1-methyldibenzothiophene）and 2,4-/1,4-DMDBT ratios,suggesting their common chemical reaction mechanisms and similar behavior with increasing maturity.Therefore,they can be effectively applied for maturity assessments.Furthermore,the TMDBTs related maturity parameters are more reliable for over-mature oils and condensates due to the relatively higher concentrations of thermodynamically unstable TMDBT isomers,i.e.1,4,6-,1,4,8-and 3,4,6-TMDBT in this study than those of 1-methyldibenzothiophene （1-MDBT） or 1,4-DMDBT.In contrast with 4,6-/1,4-DMDBT,the newly proposed （2,6 ＋ 3,6）-/1,4-DMDBT ratios for oils that originated from different types of source rocks have approximately same relationship with the oil maturity （Rc %）.This suggests that the lithology and organic facies may have relatively less influence on （2,6 ＋ 3,6）-/1,4-DMDBT ratio compared to 4,6-/1,4-DMDBT.The maturity parameters based on methylated dibenzothiophenes are particularly useful in the maturity assessments of post-and over-mature oils and condensates and can complement maturity indicators based on steranes and terpanes.展开更多
As shale exploitation is still in its infancy outside North America much research effort is being channelled into various aspects of geochemical characterization of shales to identify the most prospective basins, form...As shale exploitation is still in its infancy outside North America much research effort is being channelled into various aspects of geochemical characterization of shales to identify the most prospective basins, formations and map their petroleum generation capabilities across local, regional and basin-wide scales. The measurement of total organic carbon, distinguishing and categorizing the kerogen types in terms oil-prone versus gas-prone, and using vitrinite reflectance and Rock-Eval data to estimate thermal maturity are standard practice in the industry and applied to samples from most wellbores drilled. It is the trends of stable isotopes ratios, particularly those of carbon, the wetness ra- tio （C1/~＇（C2＋C3））, and certain chemical biomarkers that have proved to be most informative about the status of shales as a petroleum system. These data make it possible to identify production ＂sweet- spots＂, discriminate oil-, gas-liquid- and gas-prone shales from kerogen compositions and thermal ma- turities. Rollovers and reversals of ethane and propane carbon isotope ratios are particularly indica- tive of high thermal maturity exposure of an organic-rich shale. Comparisons of hopane, strerane and terpane biomarkers with vitrinite reflectance （Ro） measurements of thermal maturity highlight dis- crepancies suggesting that Ro is not always a reliable indicator of thermal maturity. Major and trace element inorganic geochemistry data and ratios provides useful information regarding provenance, paleoenvironments, and stratigraphic-layer discrimination. This review considers the data measure- ment, analysis and interpretation of techniques associated with kerogen typing, thermal maturity, sta- ble and non-stable isotopic ratios for rocks and gases derived from them, production sweet-spot identi- fication, geochemical biomarkers and inorganic chemical indicators. It also highlights uncertainties and discrepancies observed in their practical application, and the numerous outstanding questions as- sociated with them.展开更多
The oleanane parameter, i.e., OP （oleananes/（oleananes＋C30hopanes）） in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro （/%） o...The oleanane parameter, i.e., OP （oleananes/（oleananes＋C30hopanes）） in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro （/%） of 0.53 in Well M1 and 0.55 in Wells H1/Hd1/Hd2, respectively. Comparing with vitrinite reflectance （Ro/%）, the OP features a dynamic range and can indicate the oil generation window more precisely. By using OP and other geochemical indices, the oil-source correlation is also conducted. It suggests that the oils in wells M1 and M2 are derived from the source rocks in situ. The mudstone in Huachang uplift is not the main source rocks for oils in this area, The OP is also a useful oil-source correlation parameter in some Tertiary lacustrine basins.展开更多
文摘The study aimed to develop a customized Data Governance Maturity Model (DGMM) for the Ministry of Defence (MoD) in Kenya to address data governance challenges in military settings. Current frameworks lack specific requirements for the defence industry. The model uses Key Performance Indicators (KPIs) to enhance data governance procedures. Design Science Research guided the study, using qualitative and quantitative methods to gather data from MoD personnel. Major deficiencies were found in data integration, quality control, and adherence to data security regulations. The DGMM helps the MOD improve personnel, procedures, technology, and organizational elements related to data management. The model was tested against ISO/IEC 38500 and recommended for use in other government sectors with similar data governance issues. The DGMM has the potential to enhance data management efficiency, security, and compliance in the MOD and guide further research in military data governance.
基金STU Scientific Research Initiation Grant[Grant No.STF24004T]Natural Science Foundation of Guangdong Province of China[Grant No.2021B1515020103].
文摘This study explores the relationship between corporate environmental,social,and governance(ESG)disagreements and corporate debt maturity.By examining panel samples from Chinese non-financial listed companies covering 2007 to 2020,we find that ESG disagreements negatively influence corporate debt maturity.Even after conducting a series of robustness tests and addressing endogeneity concerns,the adverse effects of ESG disagreements persisted.A heterogeneity analysis shows that this negative impact is more significant for non-state-owned enterprises,small enterprises,enterprises with high capital intensity,enterprises with low analyst attention,and enterprises in high-tech industries.Through a mechanism analysis,we discovered that ESG disagreements can lead to information asymmetry and heightened default risk,subsequently affecting the maturity of corporate debt.Further analysis confirms that the negative impact of ESG on the debt structure inhibits long-term investment and exacerbates the mismatch between investment and financing terms.
基金Supported by the National Natural Science Foundation of China(U22B6004)Project of PetroChina Research Institute of Petroleum Exploration and Development(2022yjcq03)Core Technology Key Project of China Petroleum Changqing Oilfield Company(KJZX2023-01).
文摘In addition to the organic matter type,abundance,thermal maturity,and shale reservoir space,the preservation conditions of source rocks play a key factor in affecting the quantity and quality of retained hydrocarbons in source rocks of lacustrine shale,yet this aspect has received little attention.This paper,based on the case analysis,explores how preservation conditions influence the enrichment of mobile hydrocarbons in shale oil.Research showns that good preservation conditions play three key roles.(1)Ensure the retention of sufficient light hydrocarbons(C_(1)–C_(13)),medium hydrocarbons(C_(14)–C_(25))and small molecular aromatics(including 1–2 benzene rings)in the formation,which enhances the fluidity and flow of shale oil;(2)Maintain a high energy field(abnormally high pressure),thus facilitating the maximum outflow of shale oil;(3)Ensure that the retained hydrocarbons have the miscible flow condition of multi-component hydrocarbons(light hydrocarbons,medium hydrocarbons,heavy hydrocarbons,and heteroatomic compounds),so that the heavy hydrocarbons(C_(25+))and heavy components(non-hydrocarbons and asphaltenes)have improved fluidity and maximum flow capacity.In conclusion,in addition to the advantages of organic matter type,abundance,thermal maturity,and reservoir space,good preservation conditions of shale layers are essential for the formation of economically viable shale oil reservoirs,which should be incorporated into the evaluation criteria of shale oil-rich areas/segments and considered a necessary factor when selecting favorable exploration targets.
文摘Savannah,Ga.,May 20,2025-Gulfstream Aerospace Corp.today announced the 50th customer delivery of the Gulfstream G700.The aircraft was outfitted at Gulfstream's Savannah completions center.Since entering service in April 2024,the G700 operates globally,and the fleet has accumulated more than 11,700 flight hours.
基金Open access funding provided by University of Inland Norway The Research Council of Norway provided financial support(grant number 331878).
文摘Background Boars undergo physiological and biochemical changes in semen composition as they grow from puberty to sexual maturity.However,comprehensive metabolomic profiles of boar semen remain uncharacterised.Understanding metabolic alterations in semen during this period is important for optimising reproductive performance in breeding programs.The aim of this study was to characterise the semen metabolome as boars mature,utilising an untargeted metabolomic approach.Semen samples were collected from 15 Duroc boars at three developmental ages:~7 months,8.5 months,and 10 months.Sperm and seminal plasma were separated and analysed by hydrophilic interaction and reversed-phase liquid chromatography coupled with mass spectrometry to capture a wide range of metabolites.Results We identified a total of 4,491 features in boar semen,annotating 92 distinct metabolites.Amino acids,peptides and analogues constituted the most abundant components,followed by fatty acid esters.Principal component analysis(PCA)and partial least squares discriminant analysis(PLS-DA)showed a clear separation between metabolomic profiles by age groups.PERMANOVA analysis of PCA scores confirmed statistically significant differences(P<0.05)between younger(7 months)and more mature boars(8.5 months and 10 months).Pathway analysis identified porphyrin metabolism,taurine and hypotaurine metabolism,and glycerolipid metabolism as significantly enriched pathways in sperm,while glutathione and nitrogen metabolism were prominently enriched in seminal plasma.Using linear modelling,partial Spearman correlation and random forest analyses,we identified homoisovanillic acid as a key metabolite discriminating age groups in both sperm and seminal plasma.Additionally,L-glutamic acid,decanoyl-L-carnitine and N-(1,3-Thiazol-2-yl)benzenesulfonamide emerged as important sperm metabolites,while glyceric acid,myo-inositol,glycerophosphocholine,and several other compounds were identified as critical seminal plasma metabolites.Conclusion This study provides a detailed characterisation of metabolic changes in Duroc boar semen during the transition from puberty to sexual maturity.Our findings enhance the understanding of reproductive development and could inform strategies to assess sexual maturity in breeding programs.
基金the supports of the Na-tional Natural Science Foundation of China(No.U19B2007,42072202)the China Postdoctoral Science Foundation(No.2025MD774057)。
文摘Organic matter(OM)is the primary gas occurrence carrier in shale reservoirs due to their abundant nanopores.To reveal the OM pore structure,adsorption capacity and evolution during thermal maturation,this study collected data from samples spanning the entire evolution stage,from immature to over-mature.Scanning Electron Microscope(SEM)observation and low temperature gases adsorption experiments were used to qualitatively-semi-quantitatively and quantitatively analyze OM pore structure evolution,and CH_(4) isothermal adsorption experiments were used to reveal the adsorption capacity evolution.Then,the influence and mechanism of matu rity and hydrocarbon generation on pore development and adsorption capacity were quantitatively reviewed based on the experimental data.The results show that OM pores are poorly developed in the immature stage due to weak hydrocarbon generation,although micro-fractures are occasionally found at the edges of OM particles.In the low maturity stage,OM pores are partially developed due to liquid hydrocarbon generation,with liquid hydrocarbons also filling some OM pores.The contribution of total organic carbon content(TOC)to adsorption extent is not significant in these two stages.From high to high-over maturity stages,massive gaseous hydrocarbons are generated,significantly improving the surface porosity of OM.Clear positive linear correlations are observed between TOC and adsorption amount.However,the development of OM pores significantly declines when thermal maturity(R_(o))exceeds 3.5%due to excessive aromatization.The accuracy of research on the evolution of pore structure and adsorption capacity is limited by several factors:(ⅰ)errors caused by sample specification,calculation processes,parameter settings,and kerogen models in isothermal adsorption experiments and molecular simulations;(ⅱ)difficulty in achieving control variables due to the strong heterogeneity of natural maturation shale samples;and(ⅲ)the need to enhance compatibility between thermal simulation experiments and natural thermal evolution.Therefore,isothermal adsorption experiments on bulk shale and molecular simulations of intact shale model are necessary,taking into account the dynamic temperature and pressure of in-situ reservoirs.Moreover,shale samples with varying maturity,influenced by their distance from the paleo-thermal source,may provide significant verification for thermal simulation experiments.
基金funded by the National Natural Science Foundation of China(Grant No.42173054).
文摘Light hydrocarbons(LHs)are key components of petroleum,and the carbon isotopes composition(δ^(13)C)of individual LHs contains a wealth of geochemical information.Forty-four oil samples from five different basins were analyzed using gas chromatography(GC),gas chromatography-mass spectrometry(GC–MS),and gas chromatography-isotope ratio mass spectrometry(GC-IRMS).Theδ^(13)C values of forty-three LHs were recognized and determined by comparing the GC and GC-IRMS methods.The results revealed significant differences inδ^(13)C distribution characteristics among different LH compounds.Theδ^(13)C variation of individual LHs in iso-paraffins showed the widest range,followed by cycloalkanes and aromatics,whereas theδ^(13)C variation in n-paraffins showed the narrowest range.Theδ^(13)C values of most individual LHs are primarily affected by the source facies and thermal evolution.Among them,c-1,3-dimethylcyclohexane(c-1,3DMCH)is mainly sourced from higher plants but may also form through abiotic mechanisms such as catalysis or cyclization.Theδ^(13)C values of c-1,3DMCH(δ^(13)Cc-1,3DMCH)primarily exhibit parental genetic characteristics,enabling effective distinction of oil from different source facies.Specifically,theδ^(13)Cc-1,3DMCH in marine oils,lacustrine oils,terrigenous oils,and coal-formed oils are<–22‰,from–22‰to−20.2‰,from−20.2‰to−18.4‰,and>−18.4‰,respectively.Moreover,maturity is the primary controlling factor forδ^(13)C values of 3MC7(δ^(13)C3MC7,3MC7:3-methylheptane),while the source facies serve as a secondary influence.The plot ofδ^(13)Cc-1,3DMCH andδ^(13)C3MC7 was introduced to classify source facies.Asδ^(13)Cc-1,3DMCH andδ^(13)C3MC7 increase,the source facies transits from marine to lacustrine,then terrigenous,and finally coal facies.Additionally,increasingδ^(13)C3MC7 indicates a relative increase in maturity.Therefore,theδ^(13)Cc-1,3DMCH vs.δ^(13)C3MC7 plot serves as an effective tool for distinguishing source facies and assessing relative maturity.
文摘In the era of global tourism and creative economies,digital technology maturity has emerged as a critical factor for the sustainable development of small and medium enterprises(SMEs)in Indonesia.This research is implemented to find out current digital technology maturity levels among SMEs in the subdistrict of Cangkringan,district of Sleman,Yogyakarta,Indonesia,highlighting their role in fostering sustainable tourism and creative economic growth.Using a mixed-method approach,the research combines qualitative insights from in-depth interviews with three local government representatives and Focus Group Discussion with 15 SMEs in the area.Additionally,a quantitative analysis of SMEs across various sectors,including crafts and culinary services,supports the study’s conclusions.The finding reveals a significant gap between government’s training programs and the digital literacy of SMEs as well as a lack of affordable technological resources which could impede the full realization of digital benefits.Strengthening digital technology maturity among SMEs is essential for enhancing their competitiveness and long-term sustainability,yielding both financial and non-financial benefits.This also contributes to find out digital literacy gaps,impact on competitiveness and sustainability,policy and stakeholder recommendations,and government action.These insights offer valuable guidance for policymakers and stakeholders striving to support the digital transformation of SMEs in similar settings.The study also sheds light on digital literacy gaps,their impact on competitiveness and offers policy recommendations for government and stakeholders to address these challenges such as through government and community collaboration.
文摘Thermal maturation and petroleum generation modeling of shales is essential for suc- cessful exploration and exploitation of conventional and unconventional oil and gas plays. For basin- wide unconventional resource plays such modeling, when well calibrated with direct maturity meas- urements from wells, can characterize and locate production sweet spots for oil, wet gas and dry gas. The transformation of kerogen to petroleum is associated with many chemical reactions, but models typically focus on first-order reactions with rates determined by the Arrhenius Equation. A miscon- ception has been perpetuated for many years that accurate thermal maturity modeling of vitrinite re- flectance using the Arrhenius Equation and a single activation energy, to derive a time-temperature index （~TTIARa）, as proposed by Wood （1988）, is flawed. This claim was initially made by Sweeney and Burnham （1990） in promoting their ＂EasyRo＂ method, and repeated by others. This paper dem- onstrates through detailed multi-dimensional burial and thermal modeling and direct comparison of the ~TTIARR and ＂EasyRo＂ methods that this is not the case. The ~TTIA^R method not only provides a very useful and sensitive maturity index, it can reproduce the calculated vitrinite reflectance values derived from models based on multiple activation energies （e.g., ＂EasyRo＂）. Through simple expres- sions the ~TTIAaa method can also provide oil and gas transformation factors that can be flexibly scaled and calibrated to match the oil, wet gas and dry gas generation windows. This is achieved in a more-computationally-efficient, flexible and transparent way by the ~TTIARR method than the ＂EasyRo＂ method. Analysis indicates that the ＂EasyRo＂ method, using twenty activation energies and a constant frequency factor, generates reaction rates and transformation factors that do not realisti- cally model observed kerogen behaviour and transformation factors over geologic time scales.
文摘Chiromantes dehaani, as one of the dominant species in intertidal regions of the Yangtze estuary, plays an important role in the ecosystem. To study allometry and maturity in different phases, morphological data had been collected from October in 2009 to September in 2010. Morphologic data such as carapace, cheliped and abdomen were processed by cluster and piecewise linear regression analyses. Discriminat function and logistic curves were built to determine different phases and sizes at 50% maturity, respectively. The results showed that the cheliped width in males and abdomen width in females both presented obvious allometry. The sizes of 50% morphometric maturity occurred at 16.36 mm and 18.22 mm carapace width in males and females, respectively. The life history of males could be divided into three phases while that of females only had two phases according to different growth rates. A significant change in allometry of juvenile males with a break point was detected at 11.78 mm carapace width; carapace width of juvenile and adult females overlapped in a range of 13.04 - 18.64 mm. The crabs attained 50% physiological maturity at the size of 17.50 mm and 17.20 mm for females and males, respectively. For male, the size of morphological maturity was larger than that of physiological maturity, which was opposite to that of female.
基金Supported by the Important Science and Technology Program for Agriculture of Zhejiang Province(2009C2001-TZ)the Taizhou Research and Development of Applied Technology,Zhejiang Province(091TG06)~~
文摘[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable development. [Methods] A three-year field positioning experiment was carried out. In the first year, five differ- ent levels （0, 2.81, 5.61, 8.42, 11.23 t/hm~） of Astragalus sinicus ploughed at matu- rity stage were designed. And in the next two years, the amounts of ploughed As- tragalus sinicus at maturity stage were based on the natural growth amounts of As- tragalus sinicus at maturity stage of the former year in each plot field. The yields of Astragalus sinicus at maturity stage were estimated and ploughed directly before rice transplanting. Rice yield, soil nutrients, biological properties and water-stable aggre- gates of paddy fields were measured as well. [Results] The effective panicles and rice yields increased significantly after ploughing Astragalus sinicus at maturity stage. Meanwhile, the organic acid content in paddy field increased and the activities of soil phosphatases, invertase and catalase were higher. The soil dissolved organic carbon also increased with the increasing application of green manure. However, excess amount of green manure inhibited the soil microbial biomass carbon content. The macro aggregates and micro aggregates gathered to middle aggregates. [Conclusion] As green manure, the use of Astragalus sinicus at maturity stage could improve soil physiochemical and biological properties, improve soil fertility and increase rice yield significantly. But the ploughing amount of Astragalus sinicus at maturity stage before rice transplanting should be less than 8.42 t/hm2 （dry weight.
基金supported by National Key Technology R&D Program in the 11~(th) Five year Plan of China (2006BAD22B04)
文摘In this study, peaches of cv. ＇Sui Yuan＇ with different maturities were treated with 0.05 mM sodium nitroprusside （SNP）, a nitric oxide donor, for 5 min, at 28℃, and then stored at 0-1.5℃ for 30 days. Untreated fruits stored under the same conditions were used as control fruits in the experiment. The browning level, activities of polyphenol oxidase （PPO）, peroxydase （POD） and superoxide dismutase （SOD）, and quality parameters （firmness, titratable acid, total soluble solids and total sugar） were analyzed. The results showed that the firmness of SNP-treated fruit at different stage of maturity were higher than that of the control fruit after storage for 30 days. However, no significant effect was found on total soluble solid content. The titratable acid content of low maturity fruit was higher in SNP-treated one than that of the control, but the titratable acid content of high maturity fruit treated by SNP was lower than that of the control on 10th and 30th day. In addition, the combination of SNP treatment and high maturity resulted in higher activities of SOD, lower activity of PPO and POD, lower browning level. Therefore, the combination of high maturity and SNP treatment might be a useful method to well maintain honey peach fruit quality during cold storage.
文摘Based on the concept of debt duration,this paper proposes the elasticity of cash flow.Then,the debt maturity structure in project financing is discussed.The results show that in the project financing structure,the debt maturity structure is closely related with debt capacity.Higher debt ratio requires short term debt,and vise versa.
文摘Emma is one of the most successful novels by Jane Austen.This thesis analyzed the background of its heroine Emma’s growth background,her growth from conceit,snobbery,domination to maturity,and the causes of her character transformation.Her psychological growth process from innocence to maturity demonstrates women’s growth and progress in the early 19th cen tury,and inspires modern women to gradually improve in personality and better present their charms of maturity.
基金Supported by Shanghai Tobacco(Group)Corporation(2011-00600)~~
文摘CuItivars K326, Yunyan 87 and Guiyan 4 were used to investigate the curing characteristics and suitabIe harvest maturity of fresh fIue-cured tobacco Ieaves in Ankang tobacco growing areas. ResuIts indicated that the water Ioss of K326 was sIow,and the Ieaves were resistant to curing and reIative easiIy to cure. The water Ioss of Yunyan 87 and Guiyan 4 were quick, and the Ieaves with normal resistance to curing were reIative difficuIt to cure. For Guiyan 4, the shrinkage of CM1 maturity was the Iargest. For K326 and Yunyan 87, the shrinkages of CM2 maturity were the Iargest whiIe the shrinkage of CM1 maturity was the Iowest, but the difference did not reach statistical significance. The proportion of top-middIe-grade tobacco Ieaves and average price for K326 were the highest with XM2, CM2 and BM2 maturity, and for Yunyan 87 were XM1, CM3 and BM2 maturity. For K326, Ieaves with XM2, CM2 and BM2 maturity showed the balanced chemical components and the best smoking quality.
基金The study is part of the 1999–2002 research program "Municipal solid waste treatment and compost agriculture application" which is supported jointly by the Tunisian Secretariat of Scientific Research and Technology
文摘The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues （VR） collected from markets of Tunis City with residues of Posidonia oceanica （PoR）, collected from Tunis beaches. The accumulation in beaches （as well as their removal） constitutes a serious environmental problem in all Mediterranean countries particularly in Tunisia. Aerobic-thermophilic composting is the most reasonable way to profit highly-valuable content of organic matter in these wastes for agricultural purposes. The physical, chemical, and biological parameters were monitored during composting over 150 d. The most appropriate parameters were selected to establish the maturity degree. The main result of this research was the deduction of the following maturity criterion： （a） C/N ratio 〈 15; （b） NH4^＋-N 〈 400 mg/kg; （c） CO2-C 〈 2000 mg CO2-C/kg; （d） dehydrogenase activity 〈 1 mg TPF/g dry matter; （e） germination index （GI） 〉 80%. These five parameters, considered jointly are indicative of a high maturity degree and thus of a high-quality organic amendment which employed in a rational way, may improve soil fertility and soil quality. The mature compost was relatively rich in N （13.0 g/kg）, P （4.74 g/kg） and MgO （15.80 g/kg）. Thus composting definitively constitutes the most optimal option to exploit these wastes.
基金We would like to thank the National Key R&D program of China(No.2017YFE0103600)the National Natural Science Foundation of China(Nos.41830431,41672139)the China National Science and Technology Major Projects(No.2016ZX05034002-003)for financial assistance to this research.
文摘Organic matter(OM)nanopores developed in transitional facies shales,i.e.,the Upper Permian Longtan and Dalong Formations in the Yangtze Platform,China,were investigated to determine the corre-sponding influence of thermal maturity and OM types within the geological conditions.A suite of 16 core samples were taken from Type-Ⅲ Longtan shales and Type-Ⅱ Dalong shales from two wells covering a ma-turity(Ro,vitrinite reflectance)ranging from 1.22%to 1.43%and 2.62%to 2.97%,respectively.Integrated analysis of the shale samples was carried out,including field-emission scanning electron microscopy(FESEM),low-pressure N2 and CO2 adsorption,high-pressure CH4 adsorption,and mercury intrusion capillary pressure(MICP)analysis.The fluid inclusions of liquid and gas hydrocarbons trapped in calcite vein samples in Dalong shales of two wells were studied using laser Raman and fluorescence spectroscopy.FE-SEM images indicated that OM pores in different formations varied substantially in terms of shape,size,and distribution density.OM pores in Type-Ⅱ Dalong shales of Well XY1 were mainly micropore,sparsely distributed in the gas-prone kerogen with a spot-like and irregular shape,while bitumen rarely developed observable pores.In contrast,the morphology of OM pores in Type-Ⅲ Longtan shales were significantly different,which was due to differences in the OM type.The primary OM pores in some terrestrial woody debris in Longtan shales had a relatively larger pore diameter,ranging from hundreds of nanometers to a few micrometers and were al-most all rounded in shape,which might be one of the factors contributing to larger pore volume and gas adsorption capacity than Dalong shales of Well XY1.Comparing Dalong shales of Well XY1 with relatively lower thermal maturity,there were abundant spongy-like pores,densely developed in the pyrobitumen in Type-Ⅱ Dalong shales of Well EY1,with an irregular shape and diameter ranging from several to hundreds of nanometers.Many blue fluorescent oil inclusions and a small number of CH4 inclusions mixed with C2H6 could be observed within calcite veins in Dalong shales of Well XY1,whereas only CH4 inclusions could be identified within calcite veins in Dalong shales of Well EJ1.Therefore,thermal maturity not only controlled the type of hydrocarbons generated,but also makes a significant contribution to the formation of OM pores,resulting in larger pore volumes and adsorption capacity of Type-Ⅱ shale samples in the dry gas window.
基金funded by the National Natural Science Foundation of China (Grant No. 41272158)the State Key Laboratory of Petroleum Resources and Prospecting (PRP/indep-2-1302)
文摘Aromatic fractions of 140 oils and condensates that originated from different types of source rocks （marine shale,terrestrial shale and marine carbonate） were analyzed using gas chromatographymass spectrometry （GC-MS） to investigate the relative distributions of methylated dibenzothiophenes with respect to thermal maturity.The positions of methyl groups of trimethyldibenzothiophene isomers （TMDBTs） including those used in the definition of maturity indicator TMDBT index in previous studies were firmly identified by co-elution of internal standards in GC-MS analysis and by comparing with reported retention indices.A new maturity ratio related to dimethyldibenzothiophenes （DMDBTs） is proposed on the basis of the differences in thermodynamic stability among different DMDBT isomers.Another maturity index （TMDBT-I2） based on TMDBTs is also suggested on the basis of our empirical observations and presumed thermodynamic stability of TMDBT isomers.These two newly proposed （2,6 ＋ 3,6）-/1,4-DMDBT ratio and TMDBT-I2 correlate well with MDR （4-/1-methyldibenzothiophene）and 2,4-/1,4-DMDBT ratios,suggesting their common chemical reaction mechanisms and similar behavior with increasing maturity.Therefore,they can be effectively applied for maturity assessments.Furthermore,the TMDBTs related maturity parameters are more reliable for over-mature oils and condensates due to the relatively higher concentrations of thermodynamically unstable TMDBT isomers,i.e.1,4,6-,1,4,8-and 3,4,6-TMDBT in this study than those of 1-methyldibenzothiophene （1-MDBT） or 1,4-DMDBT.In contrast with 4,6-/1,4-DMDBT,the newly proposed （2,6 ＋ 3,6）-/1,4-DMDBT ratios for oils that originated from different types of source rocks have approximately same relationship with the oil maturity （Rc %）.This suggests that the lithology and organic facies may have relatively less influence on （2,6 ＋ 3,6）-/1,4-DMDBT ratio compared to 4,6-/1,4-DMDBT.The maturity parameters based on methylated dibenzothiophenes are particularly useful in the maturity assessments of post-and over-mature oils and condensates and can complement maturity indicators based on steranes and terpanes.
基金the Department of Science & Technology (DST Ministry of Science & Technology, Government of India), for providing funding for his research through the DST-Inspire Assured Opportunity of Research Career (AORC) scheme
文摘As shale exploitation is still in its infancy outside North America much research effort is being channelled into various aspects of geochemical characterization of shales to identify the most prospective basins, formations and map their petroleum generation capabilities across local, regional and basin-wide scales. The measurement of total organic carbon, distinguishing and categorizing the kerogen types in terms oil-prone versus gas-prone, and using vitrinite reflectance and Rock-Eval data to estimate thermal maturity are standard practice in the industry and applied to samples from most wellbores drilled. It is the trends of stable isotopes ratios, particularly those of carbon, the wetness ra- tio （C1/~＇（C2＋C3））, and certain chemical biomarkers that have proved to be most informative about the status of shales as a petroleum system. These data make it possible to identify production ＂sweet- spots＂, discriminate oil-, gas-liquid- and gas-prone shales from kerogen compositions and thermal ma- turities. Rollovers and reversals of ethane and propane carbon isotope ratios are particularly indica- tive of high thermal maturity exposure of an organic-rich shale. Comparisons of hopane, strerane and terpane biomarkers with vitrinite reflectance （Ro） measurements of thermal maturity highlight dis- crepancies suggesting that Ro is not always a reliable indicator of thermal maturity. Major and trace element inorganic geochemistry data and ratios provides useful information regarding provenance, paleoenvironments, and stratigraphic-layer discrimination. This review considers the data measure- ment, analysis and interpretation of techniques associated with kerogen typing, thermal maturity, sta- ble and non-stable isotopic ratios for rocks and gases derived from them, production sweet-spot identi- fication, geochemical biomarkers and inorganic chemical indicators. It also highlights uncertainties and discrepancies observed in their practical application, and the numerous outstanding questions as- sociated with them.
基金supported by the Natural Science Foundation of China(Grant No.40672093)CNPC Innovation Fund(07El001)the ESS-China Hydrocarbon Geosciences Collaboration Project under Natural Resources Canada's International Opportunities Program.
文摘The oleanane parameter, i.e., OP （oleananes/（oleananes＋C30hopanes）） in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro （/%） of 0.53 in Well M1 and 0.55 in Wells H1/Hd1/Hd2, respectively. Comparing with vitrinite reflectance （Ro/%）, the OP features a dynamic range and can indicate the oil generation window more precisely. By using OP and other geochemical indices, the oil-source correlation is also conducted. It suggests that the oils in wells M1 and M2 are derived from the source rocks in situ. The mudstone in Huachang uplift is not the main source rocks for oils in this area, The OP is also a useful oil-source correlation parameter in some Tertiary lacustrine basins.
