Reaction textures and fluid inclusions in the -2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses （Central Zone of the Limpopo Complex） suggest that the formation of the...Reaction textures and fluid inclusions in the -2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses （Central Zone of the Limpopo Complex） suggest that the formation of these zones is a result of close interplay between dehydration process along ductile shear zones triggered by H2O-CO2-salt fluids at 750--800 ℃ and 5.5--6.2 kbar, partial melting, and later exsolution of residual brine and H2O-CO2 fluids during melt crystallization at 650--700 ℃. These processes caused local variations of water and alkali activity in the fluids, resulting in various mineral assemblages within the dehydration zone. The petrological observations are substantiated by experiments on the interaction of the Sand River gneiss with the H2O-CO2-（K, Na）Cl fluids at 750 and 800 ℃ and 5.5 kbar. It follows that the interaction of biotite-amphibole gneiss with H2O-CO2-（K, Na）CI fluids is accompanied by partial melting at 750--800 ℃. Orthopyroxene-bearing assemblages are characteristic for temperature 800 ℃ and are stable in equilibrium with fluids with low salt concentrations, while salt-rich fluids produce clinopyroxene-bearing assemblages. These observations are in good agreement with the petrological data on the dehydration zones within the Sand River olthogneisses.展开更多
柜式气体绝缘开关设备(cubicle gas insulatedswitchgear,C-GIS)由于其全可靠性能高、小型化等特点在电力系统中得到广泛的应用。但由于C-GIS开关柜的主要绝缘介质SF6气体具有较强的温室效应,且其成本较高,迫切需要减少或不用SF6气体。...柜式气体绝缘开关设备(cubicle gas insulatedswitchgear,C-GIS)由于其全可靠性能高、小型化等特点在电力系统中得到广泛的应用。但由于C-GIS开关柜的主要绝缘介质SF6气体具有较强的温室效应,且其成本较高,迫切需要减少或不用SF6气体。针对C-GIS开关柜较低的气压条件,探讨SF6混合气体替代SF6的可行性。采用圆形平板电极模拟均匀场,研究均匀场、较低气压(0.1~0.25 MPa)下SF6与N2、CO2两种气体的二元混合气体在不同配比、不同电压形式(工频和负极性雷电冲击)作用下的击穿特性。试验结果表明,气压在0.25 MPa以下时,适当增大SF6混合气体的压强可以使其达到纯SF6相同的绝缘强度,为新型C-GIS开关柜的设计制造提供了关键的试验依据。展开更多
Up to now,fluid inclusion is still a powerful tool to estimate the temperature and pressure of various geological processes.CO_2-bearing inclusions are commonly found in many environments.Among the CO_2-bearing inclus...Up to now,fluid inclusion is still a powerful tool to estimate the temperature and pressure of various geological processes.CO_2-bearing inclusions are commonly found in many environments.Among the CO_2-bearing inclusions,the most typical are the ternary CO_2-H_20-NaCl inclusions.These saltbearing CO_2 V-L inclusions at room temperatures are coexisting H_2O liquid +CO_2 liquid +CO_2 vapor or coexisting H_20 liquid +CO_2 liquid(or vapor).On heating they often finally homogenize to liquid phase by the bubble disappearance,and they may form CO_2 hydrate and ice during cooling.This paper reports the application of thermodynamic models,including equations of state,to ternary CO_2-H_20-NaCl fluid inclusions.Some simple equations for pressure-temperature-salinity relation on the CO_2 hydrate-liquid-vapor(liquid) surface are developed to calculate the NaCl contents(salinities) of inclusions.With these relations and the latest CO_2 solubility and PVTx models,a new iterative approach is presented to calculate the CO_2 contents of CO_2-H_20-NaCl inclusions on the assumption that the bulk molar volume of an inclusion keeps constant at the disappearances of CO_2 hydrate and vapor bubble.A prominent merit of this method is that the compositions,molar volumes and homogenization pressures of CO_2-H_20-NaCl inclusions can be simultaneously obtained without using experimental optical volume fractions of vapor bubbles at the dissociation temperatures of CO_2 hydrates.Meanwhile,the homogenization pressures and isochores of CO_2-H_2O-NaCl fluid inclusions from updated models are briefly discussed.Calculation program code for the ternary CO_2-H_2O-NaCl inclusions with microthermometric measurement and Raman analysis data as input variables can be obtained from the author.展开更多
Neural stem cells(NSCs)have the potential for self-renewal and multidirectional differentiation,and their transplantation has achieved good efficacy in a variety of diseases.However,only 1%-10%of transplanted NSCs sur...Neural stem cells(NSCs)have the potential for self-renewal and multidirectional differentiation,and their transplantation has achieved good efficacy in a variety of diseases.However,only 1%-10%of transplanted NSCs survive in the ischemic and hypoxic microenvironment of posthemorrhagic hydrocephalus.^(Sox2)is an important factor for NSCs to maintain proliferation.Therefore,^(Sox2)-overexpressing NSCs(NSC^(Sox2))may be more successful in improving neurological dysfunction after posthemorrhagic hydrocephalus.In this study,human NSC^(Sox2)was transplanted into a posthemorrhagic hydrocephalus mouse model,and retinoic acid was administered to further promote NSC differentiation.The results showed that NSC^(Sox2)attenuated the ventricular enlargement caused by posthemorrhagic hydrocephalus and improved neurological function.NSC^(Sox2)also promoted nerve regeneration,inhibited neuroinflammation and promoted M2 polarization(anti-inflammatory phenotype),thereby reducing cerebrospinal fluid secretion in choroid plexus.These findings suggest that NSC^(Sox2)rescued ventricular enlargement and neurological dysfunction induced by posthemorrhagic hydrocephalus through neural regeneration and modulation of inflammation.展开更多
Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, ...Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, mainly due to the difficulty to freeze the solutions. This problem was solved by adding alumina powder to the solutions to facilitate nucleation of crystals. Cryogenic （-185℃） Raman spectroscopic studies of alumina-spiced solutions indicate that XNaCl is linearly correlated with the total peak area fraction of hydrohalite. Capsules of solutions made from silica capillary were prepared to simulate fluid inclusions. Most of these artificial fluid inclusions could not be totally frozen even at temperatures as low as -185℃, and the total peak area fraction of hydrohalite is not correlated linearly with XNaCI. However, the degree of deviation （△XNaCl） from the linear correlation established earlier is related to the amount of residual solution, which is reflected by the ratio （r） of the baseline ＂bump＂ area, resulting from the interstitial unfrozen brine near 3435 cm^-1, and the total hydrate peak area between 3350 and 3600 cm^-1. A linear correlation between △XNaCl and r is established to estimate XNaCl from cryogenic Raman spectroscopic analysis for fluid inclusions.展开更多
Essential oil was extracted from Artemisia lavandulaefolia DC.by steam distillation（SD） and supercritical-CO2 fluid extraction（SFE）,respectively.The constituents of the essentil oils extracted with those two metho...Essential oil was extracted from Artemisia lavandulaefolia DC.by steam distillation（SD） and supercritical-CO2 fluid extraction（SFE）,respectively.The constituents of the essentil oils extracted with those two methods were analyzed by gas chromatography-mass spectrometry（GC-MS） and insecticidal activities of the essential oils were evaluated,then the results were compared to assess their biological activity.Thirty-one compounds were identified in the essential oil extracted by SD,and its main components were eucalyptol,α,α,4-trimethyl-3-cyclohexene-1-methanol and so on.Twenty-two compounds were identified for the essential oil extracted by SFE,and its main components were cyclodecene,n-hexadecanoic acid and so on.Six chemical compositions were all contained in the essential oils extracted by the two methods,i.e.,eucalyptol,α,α,4-trimethyl-3-cyclohexene-1-methanol,caryophyllene,[3aS-（3aα,3bβ,4β,7α,7aS）]-octahydro-7-methyl-3-methylene-4-（1-methylethyl）-1H-cyclopenta[1,3]cyclopropa-[1,2]benzene,nerolidol and（-）-Spathulenol.The fumigation toxicity of the essential oil obtained by means of SD to the adults of Sitophilus zeamais is significantly higher than that of the essential oil by means of SFE.The contact toxicity of the essential oil obtained by means of SFE to the adults of S.zeamais is higher than that of the essential oil obtained by means of SD,but the difference is not significant.展开更多
Previous cryogenic Raman spectroscopic analysis of H_2O-NaCl-CaCl_2 solutions has identified the Raman peaks of various hydrates of NaCl and CaCl_2,and established a linear relationship between Raman band intensity of...Previous cryogenic Raman spectroscopic analysis of H_2O-NaCl-CaCl_2 solutions has identified the Raman peaks of various hydrates of NaCl and CaCl_2,and established a linear relationship between Raman band intensity of the hydrates and the composition of the solution（NaCl/（NaCl＋CaCl_2） molar ratio,or X_（NaC1）） using synthetic fluids,which created the opportunity to quantitatively determine the solute composition of aqueous fluid inclusions with cryogenic Raman spectroscopy.This paper aims to test the feasibility of this newly established method with natural fluid inclusions.Twenty-five fluid inclusions in quartz from various occurrences which show a high degree of freezing during the cooling processes were carefully chosen for cryogenic Raman analysis.X_（Na）Cl was calculated using their spectra and an equation established in a previous study.These inclusions were then analyzed with the thermal decrepitation-SEM-EDS method.The X_（NaCl） values estimated from the two methods show a 1：1 correlation,indicating that the new,non-destructive cryogenic Raman spectroscopic analysis method can indeed be used for fluid inclusion compositional study.展开更多
This article reports recent developments and advances in the simulation of the CO2-formation fluid displacement behaviour at the pore scale of subsurface porous media. Roughly, there are three effective visualization ...This article reports recent developments and advances in the simulation of the CO2-formation fluid displacement behaviour at the pore scale of subsurface porous media. Roughly, there are three effective visualization approaches to detect and observe the CO2-formation fluid displacement mechanism at the micro-scale, namely, magnetic resonance imaging, X-ray computed tomography and fabricated micromodels, but they are not capable of investigating the dis- placement process at the nano-scale. Though a lab-on-chip approach for the direct visualization of the fluid flow behaviour in nanoscale channels has been developed using an advanced epi-fluorescence microscopy method combined with a nanofluidic chip, it is still a qualitative analysis method. The lattice Boltzmann method （LBM） can simulate the CO2 displacement processes in a two-dimensional or three-dimensional （3D） pore structure, but until now, the CO2 displace- ment mechanisms had not been thoroughly investigated and the 3D pore structure of real rock had not been directly taken into account in the simulation of the CO2 displacement process. The status of research on the applications of CO2 displacement to enhance shale gas recovery is also analyzed in this paper. The coupling of molecular dynamics and LBM in tandem is proposed to simulate the CO2-shale gas displacement process based on the 3D digital model of shale obtained from focused ion beams and scanning electron microscopy.展开更多
We first report discovery of the spinel-garnet-orthopyroxene granulite with pure CO2 fluid inclusions from the Fuyun region of the late Paleozoic Altay orogenic belt in Central Asia, NW China. The rock is characterize...We first report discovery of the spinel-garnet-orthopyroxene granulite with pure CO2 fluid inclusions from the Fuyun region of the late Paleozoic Altay orogenic belt in Central Asia, NW China. The rock is characterized by an assemblage of garnet, orthopyroxene, spinel, cordierite, biotite, plagioclase and quartz. Symplectites of orthopyroxene and spinel, and orthopyroxene and cordierite indicate decompression under UHT conditions. Mineral chemistry shows that the or-thopyroxenes have high XMg and A12O3 contents (up to 9.23 wt%). Biotites are enriched in TiO2 and XMg and are stable under granulite facies conditions. The garnet and quartz from the rock carry monophase fluid inclusions which show peak melting temperatures of around -56.7℃, indicating a pure CO2 species being presented during the ultrahigh-T metamorphism in the Altay orogenic belt. The inclusions homogenize into a liquid phase at temperatures around 15.3-23.8℃ translating into CO2 densities of the order of 0.86-0.88 g/cm3. Based on preliminary mineral paragenesis, reaction textures and petrogenetic grid considerations, we infer that the rock was subjected to UHT conditions. The CO2-rich fluids were trapped during exhumation along a clockwise P-T path following isothermal decompression under UHT conditions.展开更多
Haigou gold deposit is a typical orogenic gold deposit. There are a reasonable amount of fluid inclusions in the gold deposit,including three types: CO2-H2O-Na Cl inclusions,pure CO2 inclusions and Na Cl-H2 O inclusio...Haigou gold deposit is a typical orogenic gold deposit. There are a reasonable amount of fluid inclusions in the gold deposit,including three types: CO2-H2O-Na Cl inclusions,pure CO2 inclusions and Na Cl-H2 O inclusions,of which most of them are CO2-bearing inclusions. The fluid salinity is 1. 43%- 9. 08%,mainly concentrated in the range of 4. 69%- 5. 41%,the density of CO2 is 0. 69- 0. 80 g / cm3,indicating that the mineralization fluid is low-medium salinity and low density fluid. A series of studies on gold-bearing quartz vein and fluid inclusions show that there exists a positive correlation between the degree of the gold mi-neralization and the amount of CO2 in the inclusions,which means the more CO2-bearing inclusions there are,the higher the content of gold is. CO2 is mainly derived from mantle fluid,and the ore-forming fluid should be derived from mantle fluid and the crust shallow fluid. The conclusions have important denotative meaning on the metallogenic mechanism of orogenic gold deposit and the deep prospecting on metal deposit.展开更多
Introduction The use of supercritical fluids such as supercritical CO<sub>2</sub>（scCO<sub>2</sub>） has provided a ’clean’ and effective alternative to traditional methods of protein delive...Introduction The use of supercritical fluids such as supercritical CO<sub>2</sub>（scCO<sub>2</sub>） has provided a ’clean’ and effective alternative to traditional methods of protein delivery systems.Here。展开更多
基金supported by Russian Foundation for Basic Research(project 10-05-00040 to OGS)Russian President Grants for Young Scientists(MD-222.2012.5 to OGS)+1 种基金grant from the National Science Foundation of South Africa(GUN:20531 92 to DDvR)University of Johannesburg as a part of the Russian South African scientific collaboration
文摘Reaction textures and fluid inclusions in the -2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses （Central Zone of the Limpopo Complex） suggest that the formation of these zones is a result of close interplay between dehydration process along ductile shear zones triggered by H2O-CO2-salt fluids at 750--800 ℃ and 5.5--6.2 kbar, partial melting, and later exsolution of residual brine and H2O-CO2 fluids during melt crystallization at 650--700 ℃. These processes caused local variations of water and alkali activity in the fluids, resulting in various mineral assemblages within the dehydration zone. The petrological observations are substantiated by experiments on the interaction of the Sand River gneiss with the H2O-CO2-（K, Na）Cl fluids at 750 and 800 ℃ and 5.5 kbar. It follows that the interaction of biotite-amphibole gneiss with H2O-CO2-（K, Na）CI fluids is accompanied by partial melting at 750--800 ℃. Orthopyroxene-bearing assemblages are characteristic for temperature 800 ℃ and are stable in equilibrium with fluids with low salt concentrations, while salt-rich fluids produce clinopyroxene-bearing assemblages. These observations are in good agreement with the petrological data on the dehydration zones within the Sand River olthogneisses.
文摘柜式气体绝缘开关设备(cubicle gas insulatedswitchgear,C-GIS)由于其全可靠性能高、小型化等特点在电力系统中得到广泛的应用。但由于C-GIS开关柜的主要绝缘介质SF6气体具有较强的温室效应,且其成本较高,迫切需要减少或不用SF6气体。针对C-GIS开关柜较低的气压条件,探讨SF6混合气体替代SF6的可行性。采用圆形平板电极模拟均匀场,研究均匀场、较低气压(0.1~0.25 MPa)下SF6与N2、CO2两种气体的二元混合气体在不同配比、不同电压形式(工频和负极性雷电冲击)作用下的击穿特性。试验结果表明,气压在0.25 MPa以下时,适当增大SF6混合气体的压强可以使其达到纯SF6相同的绝缘强度,为新型C-GIS开关柜的设计制造提供了关键的试验依据。
文摘Up to now,fluid inclusion is still a powerful tool to estimate the temperature and pressure of various geological processes.CO_2-bearing inclusions are commonly found in many environments.Among the CO_2-bearing inclusions,the most typical are the ternary CO_2-H_20-NaCl inclusions.These saltbearing CO_2 V-L inclusions at room temperatures are coexisting H_2O liquid +CO_2 liquid +CO_2 vapor or coexisting H_20 liquid +CO_2 liquid(or vapor).On heating they often finally homogenize to liquid phase by the bubble disappearance,and they may form CO_2 hydrate and ice during cooling.This paper reports the application of thermodynamic models,including equations of state,to ternary CO_2-H_20-NaCl fluid inclusions.Some simple equations for pressure-temperature-salinity relation on the CO_2 hydrate-liquid-vapor(liquid) surface are developed to calculate the NaCl contents(salinities) of inclusions.With these relations and the latest CO_2 solubility and PVTx models,a new iterative approach is presented to calculate the CO_2 contents of CO_2-H_20-NaCl inclusions on the assumption that the bulk molar volume of an inclusion keeps constant at the disappearances of CO_2 hydrate and vapor bubble.A prominent merit of this method is that the compositions,molar volumes and homogenization pressures of CO_2-H_20-NaCl inclusions can be simultaneously obtained without using experimental optical volume fractions of vapor bubbles at the dissociation temperatures of CO_2 hydrates.Meanwhile,the homogenization pressures and isochores of CO_2-H_2O-NaCl fluid inclusions from updated models are briefly discussed.Calculation program code for the ternary CO_2-H_2O-NaCl inclusions with microthermometric measurement and Raman analysis data as input variables can be obtained from the author.
基金supported by the National Natural Science Foundation of China,Nos.82473334(to LZ),82401629(to XL)the Major Scientific and Technological Achievements Transformation Project of Ningxia Hui Autonomous Region,No.2022CJE09013(to LZ)+4 种基金Mianyang Science and Technology Bureau(Mianyang Science and Technology Program),No.2023ZYDF097(to LZ)NHC Key Laboratory of Nuclear Technology Medical Transformation(Mianyang Central Hospital),No.2023HYX001(to LZ)Spinal Cord Diseases Clinical Medical Center of Yunnan Province,No.2024JSKFKT-16(to BG)the Natural Science Foundation of Sichuan Province,No.2024NSFSC1646(to XL)the China Postdoctoral Science Foundation,Nos.GZC20231811(to XL),2024T170601(to XL)and 2024M76228(to XL).
文摘Neural stem cells(NSCs)have the potential for self-renewal and multidirectional differentiation,and their transplantation has achieved good efficacy in a variety of diseases.However,only 1%-10%of transplanted NSCs survive in the ischemic and hypoxic microenvironment of posthemorrhagic hydrocephalus.^(Sox2)is an important factor for NSCs to maintain proliferation.Therefore,^(Sox2)-overexpressing NSCs(NSC^(Sox2))may be more successful in improving neurological dysfunction after posthemorrhagic hydrocephalus.In this study,human NSC^(Sox2)was transplanted into a posthemorrhagic hydrocephalus mouse model,and retinoic acid was administered to further promote NSC differentiation.The results showed that NSC^(Sox2)attenuated the ventricular enlargement caused by posthemorrhagic hydrocephalus and improved neurological function.NSC^(Sox2)also promoted nerve regeneration,inhibited neuroinflammation and promoted M2 polarization(anti-inflammatory phenotype),thereby reducing cerebrospinal fluid secretion in choroid plexus.These findings suggest that NSC^(Sox2)rescued ventricular enlargement and neurological dysfunction induced by posthemorrhagic hydrocephalus through neural regeneration and modulation of inflammation.
基金supported by an NSERC-Discovery grant(to Chi)in part by the Knowledge Innovation Program of Chinese Academy of Sciences(SIDSSE201302)
文摘Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, mainly due to the difficulty to freeze the solutions. This problem was solved by adding alumina powder to the solutions to facilitate nucleation of crystals. Cryogenic （-185℃） Raman spectroscopic studies of alumina-spiced solutions indicate that XNaCl is linearly correlated with the total peak area fraction of hydrohalite. Capsules of solutions made from silica capillary were prepared to simulate fluid inclusions. Most of these artificial fluid inclusions could not be totally frozen even at temperatures as low as -185℃, and the total peak area fraction of hydrohalite is not correlated linearly with XNaCI. However, the degree of deviation （△XNaCl） from the linear correlation established earlier is related to the amount of residual solution, which is reflected by the ratio （r） of the baseline ＂bump＂ area, resulting from the interstitial unfrozen brine near 3435 cm^-1, and the total hydrate peak area between 3350 and 3600 cm^-1. A linear correlation between △XNaCl and r is established to estimate XNaCl from cryogenic Raman spectroscopic analysis for fluid inclusions.
基金Supported by the Technology Development Project of Jilin Province,China(Nos.20090571 and 20090262)the Development and Reform Project of Jilin Province,China(No.20071033)+2 种基金the State Administration of Quality Supervision Project,China(No.2008IK253)the Jingyue Development Zone Project of Changchun City,China(No.2007C010)the Scientific Research Fund of Jilin Agricultural University,China(No.2007040)
文摘Essential oil was extracted from Artemisia lavandulaefolia DC.by steam distillation（SD） and supercritical-CO2 fluid extraction（SFE）,respectively.The constituents of the essentil oils extracted with those two methods were analyzed by gas chromatography-mass spectrometry（GC-MS） and insecticidal activities of the essential oils were evaluated,then the results were compared to assess their biological activity.Thirty-one compounds were identified in the essential oil extracted by SD,and its main components were eucalyptol,α,α,4-trimethyl-3-cyclohexene-1-methanol and so on.Twenty-two compounds were identified for the essential oil extracted by SFE,and its main components were cyclodecene,n-hexadecanoic acid and so on.Six chemical compositions were all contained in the essential oils extracted by the two methods,i.e.,eucalyptol,α,α,4-trimethyl-3-cyclohexene-1-methanol,caryophyllene,[3aS-（3aα,3bβ,4β,7α,7aS）]-octahydro-7-methyl-3-methylene-4-（1-methylethyl）-1H-cyclopenta[1,3]cyclopropa-[1,2]benzene,nerolidol and（-）-Spathulenol.The fumigation toxicity of the essential oil obtained by means of SD to the adults of Sitophilus zeamais is significantly higher than that of the essential oil by means of SFE.The contact toxicity of the essential oil obtained by means of SFE to the adults of S.zeamais is higher than that of the essential oil obtained by means of SD,but the difference is not significant.
文摘Previous cryogenic Raman spectroscopic analysis of H_2O-NaCl-CaCl_2 solutions has identified the Raman peaks of various hydrates of NaCl and CaCl_2,and established a linear relationship between Raman band intensity of the hydrates and the composition of the solution（NaCl/（NaCl＋CaCl_2） molar ratio,or X_（NaC1）） using synthetic fluids,which created the opportunity to quantitatively determine the solute composition of aqueous fluid inclusions with cryogenic Raman spectroscopy.This paper aims to test the feasibility of this newly established method with natural fluid inclusions.Twenty-five fluid inclusions in quartz from various occurrences which show a high degree of freezing during the cooling processes were carefully chosen for cryogenic Raman analysis.X_（Na）Cl was calculated using their spectra and an equation established in a previous study.These inclusions were then analyzed with the thermal decrepitation-SEM-EDS method.The X_（NaCl） values estimated from the two methods show a 1：1 correlation,indicating that the new,non-destructive cryogenic Raman spectroscopic analysis method can indeed be used for fluid inclusion compositional study.
基金The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China （Grant Nos. 51374213 and 51674251）, the State Key Research Development Program of China （Grant No. 2016YFC0600705）, the National Natural Science Fund for Distinguished Young Scholars of China （Grant No. 51125017）, the Fund for Innovative Research and Development Group Program of Jiangsu Province （Grant No. 2014- 27）, the Science Fund for Creative Research Groups of the National Natural Science Foundation of China （Grant No. 51421003）, and the Priority Academic Program Development of the Jiangsu Higher Education Institutions （PAPD 2014）.
文摘This article reports recent developments and advances in the simulation of the CO2-formation fluid displacement behaviour at the pore scale of subsurface porous media. Roughly, there are three effective visualization approaches to detect and observe the CO2-formation fluid displacement mechanism at the micro-scale, namely, magnetic resonance imaging, X-ray computed tomography and fabricated micromodels, but they are not capable of investigating the dis- placement process at the nano-scale. Though a lab-on-chip approach for the direct visualization of the fluid flow behaviour in nanoscale channels has been developed using an advanced epi-fluorescence microscopy method combined with a nanofluidic chip, it is still a qualitative analysis method. The lattice Boltzmann method （LBM） can simulate the CO2 displacement processes in a two-dimensional or three-dimensional （3D） pore structure, but until now, the CO2 displace- ment mechanisms had not been thoroughly investigated and the 3D pore structure of real rock had not been directly taken into account in the simulation of the CO2 displacement process. The status of research on the applications of CO2 displacement to enhance shale gas recovery is also analyzed in this paper. The coupling of molecular dynamics and LBM in tandem is proposed to simulate the CO2-shale gas displacement process based on the 3D digital model of shale obtained from focused ion beams and scanning electron microscopy.
文摘We first report discovery of the spinel-garnet-orthopyroxene granulite with pure CO2 fluid inclusions from the Fuyun region of the late Paleozoic Altay orogenic belt in Central Asia, NW China. The rock is characterized by an assemblage of garnet, orthopyroxene, spinel, cordierite, biotite, plagioclase and quartz. Symplectites of orthopyroxene and spinel, and orthopyroxene and cordierite indicate decompression under UHT conditions. Mineral chemistry shows that the or-thopyroxenes have high XMg and A12O3 contents (up to 9.23 wt%). Biotites are enriched in TiO2 and XMg and are stable under granulite facies conditions. The garnet and quartz from the rock carry monophase fluid inclusions which show peak melting temperatures of around -56.7℃, indicating a pure CO2 species being presented during the ultrahigh-T metamorphism in the Altay orogenic belt. The inclusions homogenize into a liquid phase at temperatures around 15.3-23.8℃ translating into CO2 densities of the order of 0.86-0.88 g/cm3. Based on preliminary mineral paragenesis, reaction textures and petrogenetic grid considerations, we infer that the rock was subjected to UHT conditions. The CO2-rich fluids were trapped during exhumation along a clockwise P-T path following isothermal decompression under UHT conditions.
基金Supported by Project of National Natural Science Foundation of China(No.41172072)
文摘Haigou gold deposit is a typical orogenic gold deposit. There are a reasonable amount of fluid inclusions in the gold deposit,including three types: CO2-H2O-Na Cl inclusions,pure CO2 inclusions and Na Cl-H2 O inclusions,of which most of them are CO2-bearing inclusions. The fluid salinity is 1. 43%- 9. 08%,mainly concentrated in the range of 4. 69%- 5. 41%,the density of CO2 is 0. 69- 0. 80 g / cm3,indicating that the mineralization fluid is low-medium salinity and low density fluid. A series of studies on gold-bearing quartz vein and fluid inclusions show that there exists a positive correlation between the degree of the gold mi-neralization and the amount of CO2 in the inclusions,which means the more CO2-bearing inclusions there are,the higher the content of gold is. CO2 is mainly derived from mantle fluid,and the ore-forming fluid should be derived from mantle fluid and the crust shallow fluid. The conclusions have important denotative meaning on the metallogenic mechanism of orogenic gold deposit and the deep prospecting on metal deposit.
文摘Introduction The use of supercritical fluids such as supercritical CO<sub>2</sub>（scCO<sub>2</sub>） has provided a ’clean’ and effective alternative to traditional methods of protein delivery systems.Here。
