Paper deals with a comparison of selected properties of several vegetable oil representatives along their accelerated thermal ageing at the temperature of 90 ℃. These properties are compared to two widely used and co...Paper deals with a comparison of selected properties of several vegetable oil representatives along their accelerated thermal ageing at the temperature of 90 ℃. These properties are compared to two widely used and commercially available mineral transformer oils. A combined insulating system （an oil-paper system） was created with the usage of mentioned oils for measurement purposes. Dissipation factor, capacity and volume resistance are characteristics measured along a thermal ageing of the oil-paper systems. Infrared spectroscopy was used as an additional method. After 1,000 hours of ageing, the dissipation factor of all systems based on vegetable oils did not exceed the value of 0.015. The volume resistance of systems containing mineral oils was approx, twice as high as the volume resistance of those with vegetable oils. The capacity on the other hand was slightly lower in the case of mineral oils application. An experiment also showed that the paper combined with the vegetable oil dries more quickly than in combination with the mineral oil. Infrared spectroscopy has not shown any expressive changes in the chemical structure of aU tested oils yet （up to 1,000 hours of ageing）.展开更多
Biodegradation usually obscures or even radically alters the original characteristics of oil biomarkers.The mixing of oil from multiple sources makes each source difficult to trace.Identifying the source of biodegrade...Biodegradation usually obscures or even radically alters the original characteristics of oil biomarkers.The mixing of oil from multiple sources makes each source difficult to trace.Identifying the source of biodegraded oil from multiple sources has always been a hard nut to crack.Rising to this challenge,in this study-we carried out a comprehensive investigation of biodegradation impacts,oil-source correlation,and oil charging history to trace the source and reveal the mixing process of biodegraded oil in the Toutunhe Formation(J_(2)t)in the eastern Junggar Basin,NW China.The oil of this area was biodegraded to different extent,consequently,many commonly used biomarker parameters(e.g.Pr/Ph,Pr/n C_(17))became less powerful for oil-source correlation.To address this problem,the resistance of many biomarkers to biodegradation was analyzed,and those of high bio resistance were selected to generate a more reliable oil-source correlation.The results revealed that biodegraded oil was a mixture of oil sourced from Lucaogou Formation(P_(2)l)and Xiaoquangou Formation(T_(2-3)xq).Core sample observation,microscopic fluorescent analysis and fluid inclusion analysis were combined to analyze comprehensively oil charging history.The analysis of accumulation process exhibited that the existing oil in J_(2)t was a mixture originated from the P_(2)l and T_(2-3)xq source rocks in two separate charging stages when it underwent a complicated process of charging,biodegradation,recharging and mixing.展开更多
The Arctic,an essential ecosystem on Earth,is subject to pronounced anthropogenic pressures,most notable being the climate change and risks of crude oil pollution.As crucial elements of Arctic environments,benthic mic...The Arctic,an essential ecosystem on Earth,is subject to pronounced anthropogenic pressures,most notable being the climate change and risks of crude oil pollution.As crucial elements of Arctic environments,benthic microbiomes are involved in climate-relevant biogeochemical cycles and hold the potential to remediate upcoming contamination.Yet,the Arctic benthic microbiomes are among the least explored biomes on the planet.Here we combined geochemical analyses,incubation experiments,and microbial community profiling to detail the biogeography and biodegradation potential of Arctic sedimentary microbiomes in the northern Barents Sea.The results revealed a predominance of bacterial and archaea phyla typically found in the deep marine biosphere,such as Chloroflexi,Atribacteria,and Bathyarcheaota.The topmost benthic communities were spatially structured by sedimentary organic carbon,lacking a clear distinction among geographic regions.With increasing sediment depth,the community structure exhibited stratigraphic variability that could be correlated to redox geochemistry of sediments.The benthic microbiomes harbored multiple taxa capable of oxidizing hydrocarbons using aerobic and anaerobic pathways.Incubation of surface sediments with crude oil led to proliferation of several genera from the so-called rare biosphere.These include Alkalimarinus and Halioglobus,previously unrecognized as hydrocarbon-degrading genera,both harboring the full genetic potential for aerobic alkane oxidation.These findings increase our understanding of the taxonomic inventory and functional potential of unstudied benthic microbiomes in the Arctic.展开更多
An ultra-light and high porosity nano microfibril aerogel was prepared from konjac glucomannan（KGM） by the electrospinning and freeze-drying. The structure of aerogel was analyzed by scanning electron microscopy（SE...An ultra-light and high porosity nano microfibril aerogel was prepared from konjac glucomannan（KGM） by the electrospinning and freeze-drying. The structure of aerogel was analyzed by scanning electron microscopy（SEM） and X-ray diffraction（XRD） while the density and compressive strength of the samples were studied separately. Results reveal that porous network structure of the KGM nano microfibril aerogel is constructed by intermolecular hydrogen bonds in random and interpenetrate way. The nano microfibril structure presents in the KGM aerogel,which is an important reason of its high density and compressive strength. There is a potential application for this unique nano microfibril aerogel in the absorption of biodegradation bacteria to solve problems in marine oil spill pollution.展开更多
By aid of gas chromatogram/mass spectrometry(GC-MS),the distributions and the compositions of biomarkers in a set of sequentially biodegraded oils from Liaohe Basin,China,have been quantitatively analyzed,and it has b...By aid of gas chromatogram/mass spectrometry(GC-MS),the distributions and the compositions of biomarkers in a set of sequentially biodegraded oils from Liaohe Basin,China,have been quantitatively analyzed,and it has been found that during the biodegradation process of crude oils,the molecular maturity parameters such as Ts/Tm,homohopane C3122S/(22S+22R)and sterane C2920S/(20S+20R)ratios will be affected to different extent.The results show that except homohopane C3122S/(22S+22R)ratio,Ts/Tm ratio will decrease with increasing biodegradation,but for C2920S/(20S+20R)ratio,it will almost remain constant in slightly and moderately biodegraded oils,and then will increase quickly in severely biodegraded oils.The main reason is that there are some differences in the ability of resistant biodegradation for different isomer of biomarkers with different stereo configuration,resulting in the fact that destroying rate by bacteria for those biomarkers with weak ability will be higher than those with strong ability in resistant biodegradation.For example,18α(H)-22,29,30-trisnorhopanes(Ts)will be destroyed more quickly than 17α(H)-22,29,30-trisnorshopanres(Tm),and 20R isomer is more quickly than 20S isomer for C29 sterane,resulting in the relative ratios changed with increasing biodegradation.Therefore,much more attention should be paid to the biodegradation extent of crude oils and the type of biomarker maturity indicators,when the distributions and the compositions of biomarkers in biodegraded oils are used to determine the maturity of biodegraded oils.展开更多
By the aid of GC-MS technique,a series of sequentially biodegraded oils from Liaohe Basin have been analyzed.The results show that the concentrations and relative compositions of various aromatic compounds in the biod...By the aid of GC-MS technique,a series of sequentially biodegraded oils from Liaohe Basin have been analyzed.The results show that the concentrations and relative compositions of various aromatic compounds in the biodegraded crude oils will change with increasing biodegradation degree.The concentrations of alkyl naphthalenes,alkyl phenanthrenes,alkyl dibenzothiophene are decreased,and the concentration of triaromatic steroids will increase with increasing biodegradation degree in biodegraded oils.Those phenomena indicate that various aromatic compounds are more easily biodegraded by bacteria like other kinds of hydrocarbons such as alkanes,but different series of aromatic compounds have a varied ability to resistant to biodegradation.The ratios of dibenzothiophene to phenenthrene(DBTH/P)and methyl dibenzothiophene to methyl phenanthrene(MDBTH/MP)are related to the features of depositional environment for source rocks such as redox and ancient salinity.However,in biodegraded oils,the two ratios increase quickly with the increase of the biodegradation degree,indicating that they have lost their geochemical significance.In this case,they could not be used to evaluate the features of depositional environment.Methyl phenanthrene index,methyl phenanthrene ratio and methyl dibenzoyhiophene ratio are useful aromatic maturity indicators for the crude oils and the source rocks without vitrinite.But for biodegraded oils,those aromatic maturity indicators will be affected by biodegradation and decrease with the increase of the biodegradation degree.Therefore,those aromatic molecular maturity indicators could not be used for biodegraded oils.展开更多
The saturated hydrocarbon fraction of a heavily biodegraded crude oil from Liaohe oilfield was analyzed by using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×...The saturated hydrocarbon fraction of a heavily biodegraded crude oil from Liaohe oilfield was analyzed by using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS). The "humps", which was termed as unresolved complex mixtures (UCMs) in conventional gas chromatographic analysis, was separated for identification of the individual compound. Main compounds of UCMs were identified according to the combined information of characteristics of GC×GC chromatogram and time-of-flight mass spectra. It's found that UCMs are mainly composed of great number of ring compounds with extremely low concentration. The ring compounds are separated according to their boiling point diversity in the first dimension column, then to their polarity or ring number variety in the second dimension column. In the sample there are two groups of UCMs, i.e., the first group compounds with boiling point lower that of C24 and the second group compounds with boiling point higher than that of C24. The first group of UCMs mainly consists of monocyclic, bicyclic and tricyclic ring compounds. The first group of UCMs is mainly composed of saturated hydrocarbons, in which the percentage of ring compounds with signal-to-noise ratio above 100 is about 75% of the total quantity of saturated hydrocarbon, while its mass is over 80% of the total saturated hydrocarbon. The second group of UCMs is mainly composed of tetracyclic and pentacyclic ring compounds, in which the percentage of UCM compounds with signal-to-noise ratio over 100 is about 17% of the total quantity of saturated hydrocarbon, and its mass is about 0.5% of the total saturated hydrocarbon. The results of this study are helpful for heavy oil developing and genesis mechanism understanding.展开更多
文摘Paper deals with a comparison of selected properties of several vegetable oil representatives along their accelerated thermal ageing at the temperature of 90 ℃. These properties are compared to two widely used and commercially available mineral transformer oils. A combined insulating system （an oil-paper system） was created with the usage of mentioned oils for measurement purposes. Dissipation factor, capacity and volume resistance are characteristics measured along a thermal ageing of the oil-paper systems. Infrared spectroscopy was used as an additional method. After 1,000 hours of ageing, the dissipation factor of all systems based on vegetable oils did not exceed the value of 0.015. The volume resistance of systems containing mineral oils was approx, twice as high as the volume resistance of those with vegetable oils. The capacity on the other hand was slightly lower in the case of mineral oils application. An experiment also showed that the paper combined with the vegetable oil dries more quickly than in combination with the mineral oil. Infrared spectroscopy has not shown any expressive changes in the chemical structure of aU tested oils yet （up to 1,000 hours of ageing）.
基金supported by a grant from National Science Foundation for Young Scientists of China(Grant No.41702143)Natural Science Foundation of Shandong Province of China(ZR2016DL06+3 种基金ZR2017LD005)the Fundamental Research Funds for the Central Universities(17CX02006A)the Foundation of Shandong Provincial Key Laboratory of Depositional Mineralization&Sedimentary Mineral(DMSM2017063)the major science and technology project of Xinjiang Petroleum Administration Bureau of CNPC(2017E-0401)。
文摘Biodegradation usually obscures or even radically alters the original characteristics of oil biomarkers.The mixing of oil from multiple sources makes each source difficult to trace.Identifying the source of biodegraded oil from multiple sources has always been a hard nut to crack.Rising to this challenge,in this study-we carried out a comprehensive investigation of biodegradation impacts,oil-source correlation,and oil charging history to trace the source and reveal the mixing process of biodegraded oil in the Toutunhe Formation(J_(2)t)in the eastern Junggar Basin,NW China.The oil of this area was biodegraded to different extent,consequently,many commonly used biomarker parameters(e.g.Pr/Ph,Pr/n C_(17))became less powerful for oil-source correlation.To address this problem,the resistance of many biomarkers to biodegradation was analyzed,and those of high bio resistance were selected to generate a more reliable oil-source correlation.The results revealed that biodegraded oil was a mixture of oil sourced from Lucaogou Formation(P_(2)l)and Xiaoquangou Formation(T_(2-3)xq).Core sample observation,microscopic fluorescent analysis and fluid inclusion analysis were combined to analyze comprehensively oil charging history.The analysis of accumulation process exhibited that the existing oil in J_(2)t was a mixture originated from the P_(2)l and T_(2-3)xq source rocks in two separate charging stages when it underwent a complicated process of charging,biodegradation,recharging and mixing.
基金the Bundesministerium für Bildung und Forschung(BMBF)-funded deNBI cloud within German Network for Bioinformatics Infrastructure(de.NBI)(Nos.031A532B,031A533A,031A533B,031A534A,031A535A,031A537A,031A537B,031A537C,031A537D,031A538A)for providing computational resources.Florin Musat was funded by the Helmholtz Association of German Research Centres Grant ERC-RA-0020+2 种基金the Novo Nordisk Foundation through an NNF Young Investigator Award,Grant NNF22OC0071609 ReFuel(grants to F.M.).Song-Can Chen is supported by Marie Skłodowska-Curie Actions 2021(postdoctoral fellowship 101059607 to S.C.C.).All sequencing data generated in this study have been deposited in the Sequence Read Archive under BioProject PRJNA1017987(SAMN37419328-SAMN374193).
文摘The Arctic,an essential ecosystem on Earth,is subject to pronounced anthropogenic pressures,most notable being the climate change and risks of crude oil pollution.As crucial elements of Arctic environments,benthic microbiomes are involved in climate-relevant biogeochemical cycles and hold the potential to remediate upcoming contamination.Yet,the Arctic benthic microbiomes are among the least explored biomes on the planet.Here we combined geochemical analyses,incubation experiments,and microbial community profiling to detail the biogeography and biodegradation potential of Arctic sedimentary microbiomes in the northern Barents Sea.The results revealed a predominance of bacterial and archaea phyla typically found in the deep marine biosphere,such as Chloroflexi,Atribacteria,and Bathyarcheaota.The topmost benthic communities were spatially structured by sedimentary organic carbon,lacking a clear distinction among geographic regions.With increasing sediment depth,the community structure exhibited stratigraphic variability that could be correlated to redox geochemistry of sediments.The benthic microbiomes harbored multiple taxa capable of oxidizing hydrocarbons using aerobic and anaerobic pathways.Incubation of surface sediments with crude oil led to proliferation of several genera from the so-called rare biosphere.These include Alkalimarinus and Halioglobus,previously unrecognized as hydrocarbon-degrading genera,both harboring the full genetic potential for aerobic alkane oxidation.These findings increase our understanding of the taxonomic inventory and functional potential of unstudied benthic microbiomes in the Arctic.
基金supported by the National Natural Science Foundation of China((31471704 and 31271837)major projects of industries,university and research in Fujian Province(2013N5003)
文摘An ultra-light and high porosity nano microfibril aerogel was prepared from konjac glucomannan（KGM） by the electrospinning and freeze-drying. The structure of aerogel was analyzed by scanning electron microscopy（SEM） and X-ray diffraction（XRD） while the density and compressive strength of the samples were studied separately. Results reveal that porous network structure of the KGM nano microfibril aerogel is constructed by intermolecular hydrogen bonds in random and interpenetrate way. The nano microfibril structure presents in the KGM aerogel,which is an important reason of its high density and compressive strength. There is a potential application for this unique nano microfibril aerogel in the absorption of biodegradation bacteria to solve problems in marine oil spill pollution.
基金Supported by Key Technologies R&D Programme(Grant No.2004BA616A02-04-02-01)
文摘By aid of gas chromatogram/mass spectrometry(GC-MS),the distributions and the compositions of biomarkers in a set of sequentially biodegraded oils from Liaohe Basin,China,have been quantitatively analyzed,and it has been found that during the biodegradation process of crude oils,the molecular maturity parameters such as Ts/Tm,homohopane C3122S/(22S+22R)and sterane C2920S/(20S+20R)ratios will be affected to different extent.The results show that except homohopane C3122S/(22S+22R)ratio,Ts/Tm ratio will decrease with increasing biodegradation,but for C2920S/(20S+20R)ratio,it will almost remain constant in slightly and moderately biodegraded oils,and then will increase quickly in severely biodegraded oils.The main reason is that there are some differences in the ability of resistant biodegradation for different isomer of biomarkers with different stereo configuration,resulting in the fact that destroying rate by bacteria for those biomarkers with weak ability will be higher than those with strong ability in resistant biodegradation.For example,18α(H)-22,29,30-trisnorhopanes(Ts)will be destroyed more quickly than 17α(H)-22,29,30-trisnorshopanres(Tm),and 20R isomer is more quickly than 20S isomer for C29 sterane,resulting in the relative ratios changed with increasing biodegradation.Therefore,much more attention should be paid to the biodegradation extent of crude oils and the type of biomarker maturity indicators,when the distributions and the compositions of biomarkers in biodegraded oils are used to determine the maturity of biodegraded oils.
基金Supported by Key Technologies R&D Programme(Grant No.2004BA616A02-04-02-01)
文摘By the aid of GC-MS technique,a series of sequentially biodegraded oils from Liaohe Basin have been analyzed.The results show that the concentrations and relative compositions of various aromatic compounds in the biodegraded crude oils will change with increasing biodegradation degree.The concentrations of alkyl naphthalenes,alkyl phenanthrenes,alkyl dibenzothiophene are decreased,and the concentration of triaromatic steroids will increase with increasing biodegradation degree in biodegraded oils.Those phenomena indicate that various aromatic compounds are more easily biodegraded by bacteria like other kinds of hydrocarbons such as alkanes,but different series of aromatic compounds have a varied ability to resistant to biodegradation.The ratios of dibenzothiophene to phenenthrene(DBTH/P)and methyl dibenzothiophene to methyl phenanthrene(MDBTH/MP)are related to the features of depositional environment for source rocks such as redox and ancient salinity.However,in biodegraded oils,the two ratios increase quickly with the increase of the biodegradation degree,indicating that they have lost their geochemical significance.In this case,they could not be used to evaluate the features of depositional environment.Methyl phenanthrene index,methyl phenanthrene ratio and methyl dibenzoyhiophene ratio are useful aromatic maturity indicators for the crude oils and the source rocks without vitrinite.But for biodegraded oils,those aromatic maturity indicators will be affected by biodegradation and decrease with the increase of the biodegradation degree.Therefore,those aromatic molecular maturity indicators could not be used for biodegraded oils.
文摘The saturated hydrocarbon fraction of a heavily biodegraded crude oil from Liaohe oilfield was analyzed by using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS). The "humps", which was termed as unresolved complex mixtures (UCMs) in conventional gas chromatographic analysis, was separated for identification of the individual compound. Main compounds of UCMs were identified according to the combined information of characteristics of GC×GC chromatogram and time-of-flight mass spectra. It's found that UCMs are mainly composed of great number of ring compounds with extremely low concentration. The ring compounds are separated according to their boiling point diversity in the first dimension column, then to their polarity or ring number variety in the second dimension column. In the sample there are two groups of UCMs, i.e., the first group compounds with boiling point lower that of C24 and the second group compounds with boiling point higher than that of C24. The first group of UCMs mainly consists of monocyclic, bicyclic and tricyclic ring compounds. The first group of UCMs is mainly composed of saturated hydrocarbons, in which the percentage of ring compounds with signal-to-noise ratio above 100 is about 75% of the total quantity of saturated hydrocarbon, while its mass is over 80% of the total saturated hydrocarbon. The second group of UCMs is mainly composed of tetracyclic and pentacyclic ring compounds, in which the percentage of UCM compounds with signal-to-noise ratio over 100 is about 17% of the total quantity of saturated hydrocarbon, and its mass is about 0.5% of the total saturated hydrocarbon. The results of this study are helpful for heavy oil developing and genesis mechanism understanding.
