The microstructure differences of the Triassic Chang 6 and Chang 8 members tight reservoirs in the Longdong area of Ordos Basin were compared by means of cast thin sections, scanning electron microscope, X-ray diffrac...The microstructure differences of the Triassic Chang 6 and Chang 8 members tight reservoirs in the Longdong area of Ordos Basin were compared by means of cast thin sections, scanning electron microscope, X-ray diffraction, and constant rate mercury injection. Their pore evolution models were established, and the effects of main diagenesis on densification were examined. The throat is the main factor controlling the physical properties of the Chang 6 and Chang 8 members reservoirs: The lower the permeability, the smaller and the more concentrated the throat radius and the larger the proportion of the throats in the effective storage space. There are several obvious differences between Chang 6 and Chang 8 members:(1) with the increase of permeability, the contribution of the relative large throats to the permeability in the Chang 8 member reservoir is more than that in the Chang 6 member reservoir;(2) the control effect on pore-throat ratio of the nano-throats in the Chang 6 member reservoir is more significant. The sedimentary action determines the primary pore structure of the Chang 6 and Chang 8 members sand bodies, and the diagenesis is the main factor controlling the densification of the reservoirs. Because of the difference in rock fabrics and the chlorite content of Chang 6 and Chang 8, the strong compaction resulted in less porosity reduction(17%) of the Chang 81 reservoir with larger buried depth and larger ground temperature than the Chang 63 reservoir(19%). The siliceous, calcareous and clay minerals cement filling the pores and blocking the pore throat, which is the key factor causing the big differences between the reservoir permeability of Chang 6 and Chang 8 members.展开更多
In order to analyze the normal deviatoric stress that viscous-elastic fluid acting on the residual oil under the situation of different flooding conditions and different permeabilities, Viscous-elastic fluid flow equa...In order to analyze the normal deviatoric stress that viscous-elastic fluid acting on the residual oil under the situation of different flooding conditions and different permeabilities, Viscous-elastic fluid flow equation is established in the micro pore by choosing the continuity equation, motion equation and the upper-convected Maxwell constitutive equation, the flow field is computed by using numerical analysis, the forces that driving fluid acting on the residual oil in micro pore are got, and the influence of flooding conditions, pore width and viscous-elasticity of driving fluid on force is compared and analyzed. The results show that: the more viscous-elasticity of driving fluid increases, the greater the normal deviatoric stress acting on the residual oil increases;using constant pressure gradient flooding, the lager the pore width is, the greater normal deviatoric stress acting on the residual oil will be.展开更多
The Micro pore volume in porous materials usually interests many researchers. However, there has been few, if not, direct method to determine it. A strategy of combining mercury porosimetry with pre adsorption is pr...The Micro pore volume in porous materials usually interests many researchers. However, there has been few, if not, direct method to determine it. A strategy of combining mercury porosimetry with pre adsorption is proposed in the present paper. The total pore volume in activated carbon is determined through direct measurements for the first time. The application scope of mercury porosimetry is also enlarged. Besides, the present experiments also confirmed the preference of adsorption to the smaller pores even in the range of meso and macro pores.展开更多
Rational regulation on pore structure and active site density plays critical roles in enhancing the performance of Fe-N-C catalysts. As the microporous structure of the carbon substrate is generally regarded as the ac...Rational regulation on pore structure and active site density plays critical roles in enhancing the performance of Fe-N-C catalysts. As the microporous structure of the carbon substrate is generally regarded as the active site hosts, its hostility to electron/mass transfer could lead to the incomplete fulfillment of the catalytic activity. Besides, the formation of inactive metallic Fe particles during the conventional catalyst synthesis could also decrease the active site density and complicate the identification of real active site. Herein, we developed a facial hydrogen etching methodology to yield single site Fe-N-C catalysts featured with micro/mesoporous hierarchical structure. The hydrogen concentration in pyrolysis process was designated to effectively regulate the pore structure and active site density of the resulted catalysts.The optimized sample achieves excellent ORR catalytic performance with an ultralow H2O2 yield(1%)and superb stability over 10,000 cycles. Our finding provides new thoughts for the rational design of hierarchically porous carbon-based materials and highly promising non-precious metal ORR catalysts.展开更多
Micro-pore is a very common material defect. In the present paper, the temperature fields of medium carbon steel joints with and without micro-pore defect during linear friction welding （LFW） were investigated by us...Micro-pore is a very common material defect. In the present paper, the temperature fields of medium carbon steel joints with and without micro-pore defect during linear friction welding （LFW） were investigated by using finite element method. The effect of micro-pore defect on the axial shortening of joints during LFW was examined. The x- and y-direction displacements of micro-pore during the LFW process were also studied. In addition, the shape of micro-pore after LFW was observed. The heat conducted from the weld inteace to the specimen interior. The fluctuation range of the temperature curves for the joint with micro-pore is larger than that without micro-pore. Position of micro-pore changes with the change of the friction time. The circular shape of micro-pore becomes oval after welding.展开更多
Based on scanning electron microscopy and nitrogen adsorption experiment at low temperature, the pore types and structures of the Longmaxi Formation shale in the Dianqianbei area, SW China were analyzed, and a molecul...Based on scanning electron microscopy and nitrogen adsorption experiment at low temperature, the pore types and structures of the Longmaxi Formation shale in the Dianqianbei area, SW China were analyzed, and a molecular model was built. According to mathematical statistics, the validation of the model was solved by converting it into a mathematical formula. It is found by SEM that the pores in clay mineral layers and organic pores occupy most of the pores in shale; the nitrogen adsorption experiment at low temperature reveals that groove pores formed by flaky particles and micro-pores are the main types of pores, and the results of the two are in good agreement. A molecular model was established by illite and graphene molecular structures. Moreover, based on the fractal theory and the Frenkel-Halsey-Hill formula, a modified Frenkel-Halsey-Hill formula was proposed. The reliability of the molecular model was verified to some extent by obtaining parameters such as the fractal dimension, replacement rate and fractal coefficients of correction, and mathematical calculation. This study provides the theoretical basis for quantitative study of shale reservoirs.展开更多
Micro-pored CA6 -MA lightweight material with CAM： MA mass ratio of 7：3 was prepared using Al（OH） 3, MgCO3 and CaCO3 as starting materials, and anthracite. sweet potato starch and anthracite ＋ sweet potato starch...Micro-pored CA6 -MA lightweight material with CAM： MA mass ratio of 7：3 was prepared using Al（OH） 3, MgCO3 and CaCO3 as starting materials, and anthracite. sweet potato starch and anthracite ＋ sweet potato starch as pore forming agent （PFA） with an addition of 10 mass%, 20 mass% and 30 mass%, respectively. The starting materials were dry mixed, wet co-milled in a ball mill for 1 h. slip cast into cylindrical specimens with a diameter of 60 ram. and then calcined at 1 450 ℃ for 3 h. With the increase of PFA addition,, apparent porosity increases, and bulk density decreases. The influence of different PFAs on properties of the micro-pored LW CAM -MA aggregate was investigated. The achieved CAM - MA, by adding 30% sweet potato starch, has a porosity of 76. 8%, bulk density of 0. 78 g · cm^ - 3 and median pore size of 1.90 μm.展开更多
A new low-cost corrosion-resistant rebar（HRB400 R） was designed and fabricated by chromium micro-alloying. The effects of Cr on the passivation and corrosion behavior of this rebar in the simulated concrete pore sol...A new low-cost corrosion-resistant rebar（HRB400 R） was designed and fabricated by chromium micro-alloying. The effects of Cr on the passivation and corrosion behavior of this rebar in the simulated concrete pore solutions were studied systematically, and its improved corrosion resistance was revealed. In the Cl--free saturated Ca（OH）_2 solution, the HRB400 R rebar presented nearly the same passive film and similar passivation ability compared to the common carbon steel rebar. In the long-term immersion corrosion test in the Cl--contained Ca（OH）_2 solution, the HRB400 R rebar presented improved corrosion resistance and obvious longer passivation-maintaining period. Micro-alloying of Cr element in the rebar matrix enhanced its corrosion resistance against Cl--attack and retarded the corrosion initiation in the matrix. In the alkaline Na Cl salt spraying test, the HRB400 R rebar also presented obviously lower mass-loss rate. The enrichment of Cr element in the rust layer improved its retardant effect to the penetration of aggressive medium, and decreased the corrosion propagation rate of the rebar.展开更多
The microstructure of the RE silicide alloy was studied by SEM. The feature of the phase and the distribution of Ca, P, Al were analyzed, especially the distribution of micro-cracks and its composition were determined...The microstructure of the RE silicide alloy was studied by SEM. The feature of the phase and the distribution of Ca, P, Al were analyzed, especially the distribution of micro-cracks and its composition were determined. The result demonstrates that only a few phosphides contribute to the spontaneous crumbling of the RE silicide alloy by reacting with water and forming oxide or phosphorus oxide. The phosphorus content is not the critical factor of disintegration in the alloy studied.展开更多
The pressure-sensitive effect on the pore structure of sandstone was investigated using X-ray computed micro-tomography and QEMSCAN quantitative mineral analysis. In a physical simulation study, we extracted the pore ...The pressure-sensitive effect on the pore structure of sandstone was investigated using X-ray computed micro-tomography and QEMSCAN quantitative mineral analysis. In a physical simulation study, we extracted the pore network model from digital cores at different confining pressures and evaluated the effect of pressure sensitivity on the multiphase displacement process. In both the pore network model and QEMSCAN scanning, the pore structure was observed to be damaged under a high confining pressure. Due to their different scales, the pores and throats exhibited inhomogeneous changes; further, the throats exhibited a significant variation compared to that exhibited by the pores. Meanwhile, the heterogeneity of the pore structure under the two aforementioned activities was aggravated by the elastic-plastic deformation of the pore structure.The pressure-sensitive effect increased the proportion of mineral particles, such as quartz(the main component of the core skeleton), and reduced the proportion of clay minerals. The clay minerals were originally attached to the pore walls or interspersed in the pores; however, as the pressure increased, the clay minerals accumulated in the pores resulting in blockage of the pores. While simulating the multiphase displacement process, increasing the confining pressure was observed to severely restrict the flowability of oil and water. This study promises to improve the efficiency of reservoir development in terms of oil and gas exploitation.展开更多
Microstructure of shale formation is the key to understanding its petrophysical and chemical properties.Optical microscopy, scanning electron microscopy and micro-computed tomography(μ-CT) have been combined for char...Microstructure of shale formation is the key to understanding its petrophysical and chemical properties.Optical microscopy, scanning electron microscopy and micro-computed tomography(μ-CT) have been combined for characterization of microstructure of Longmaxi(LMX)shale from Shizhu area, Sichan Basin. The results indicate that laminated LMX shale consists of mineral matrix-rich layers and organic matter(OM)-rich layers at micrometer scale in two and three dimensions. Mineral matrix layers,mainly consisting of interparticle pores and intraplatelet pores, are approximately parallel to the bedding plane.Pyrite-rich layer, mainly containing intercrystalline pores,shows a strong preferred orientation parallel to the bedding plane. OM-rich layer, mainly containing OM pores, seems to be discontinuous. In addition, intercrystalline pores are enriched in some layers, while OM pores are distributed irregularly in matrix layers. This vertical heterogeneity of pore microscopic structures in LMX shale is of great importance to understand its petrophysical and chemical properties.展开更多
Using ploughing-extrusion method, a cross-connected finned micro-grooves structure was formed on the surface of copper strips with thickness of 0.4 mm. The structure was fabricated by making ‘V’-grooves in copper st...Using ploughing-extrusion method, a cross-connected finned micro-grooves structure was formed on the surface of copper strips with thickness of 0.4 mm. The structure was fabricated by making ‘V’-grooves in copper strips and perpendicular ‘V’-grooves on the opposite side that intersect the first set of grooves. Micro pores appear at the intersection of these cross-connected grooves, and micro fins appear on the groove fringes. So it can be defined as ‘pore-groove-fin’ structure. The preferable ‘pore-groove-fin’ structure can be obtained under the condition that the tool edge inclination angle (χγ) is 45°, both the major extrusion angle (γo) and the minor extrusion angle (γ 0′ ) are 30°, both the major formation angle (β) and the minor formation angle (β′) are 10°, the ploughing-extrusion depth (fd) is 0.32 mm and the groove pitch is 0.4 mm on surfaces A and B. The formed included angle of groove A is 70°, and the groove depth is 0.3 mm, while the included angle of opposite perpendicular groove B is 20° with the groove depth of 0.35 mm. The obtained fin height is 0.15 mm, the elliptical pore length is 0.2 mm and the width is 0.05 mm. Experiments show that fd has the greatest influence on the formation of micro pores. Bulges appear on the opposite surface B when the ploughing-extrusion depth on surface A (fdA) reaches a critical value. The ploughing-extrusion depth on surface B (fdB) has great influence on the re-growth of fin structure.展开更多
Recently a new kind stent,porous drug-eluting stent,has been developed to overcome the problems of bare metal stent(BMS)and drug-eluting stent(DES),and the clinic results reveal that it combined the advantage of BMS a...Recently a new kind stent,porous drug-eluting stent,has been developed to overcome the problems of bare metal stent(BMS)and drug-eluting stent(DES),and the clinic results reveal that it combined the advantage of BMS and DES.In this paper,a new method to fabricate surface pores on 316L stainless steel stent using anodic oxidation of aluminum mask film deposited by magnetron sputtering on 316L substrate was reported.The effect of experimental parameters,such as anodization time,anodization voltage,anodization solution and anodization temperature,on the pores'size distribution and density are investigated using SEM.It is found that the pores characterizations strongly depend on anodization time and pores expanding rate through AAO films and on stainless steel surface.展开更多
A novel process for fabricating an in-situ micro-porous on 316 L stainless steel was described.Aluminum films about 0.7-1.4 m in thickness were deposited on 316 L stainless steel surface by magnetron sputtering.The fi...A novel process for fabricating an in-situ micro-porous on 316 L stainless steel was described.Aluminum films about 0.7-1.4 m in thickness were deposited on 316 L stainless steel surface by magnetron sputtering.The films were then anodized in 0.3 M oxalic acid.Through appropriate chemical dissolution,the alumina film was removed and the underlying micro-porous 316 L with diameters ranging from 500 nm to 2.4m was obtained.The morphology of the porous 316 L surface was examined by scanning electron microscope.The results indicate that the thickness of aluminum films and the anodizing potential have a combined action on the formation of porous structure on 316 L surface.Then anodic current density could be affected evidently by the film thickness.The pores size increases obviously with the increasing of the anodizing potential,when the thickness of aluminum film was about 1.4m.展开更多
基金Supported by the China National Science and Technology Major Project(20162X050500062011ZX05044)the National Natural Science Foundation of China(41102083)
文摘The microstructure differences of the Triassic Chang 6 and Chang 8 members tight reservoirs in the Longdong area of Ordos Basin were compared by means of cast thin sections, scanning electron microscope, X-ray diffraction, and constant rate mercury injection. Their pore evolution models were established, and the effects of main diagenesis on densification were examined. The throat is the main factor controlling the physical properties of the Chang 6 and Chang 8 members reservoirs: The lower the permeability, the smaller and the more concentrated the throat radius and the larger the proportion of the throats in the effective storage space. There are several obvious differences between Chang 6 and Chang 8 members:(1) with the increase of permeability, the contribution of the relative large throats to the permeability in the Chang 8 member reservoir is more than that in the Chang 6 member reservoir;(2) the control effect on pore-throat ratio of the nano-throats in the Chang 6 member reservoir is more significant. The sedimentary action determines the primary pore structure of the Chang 6 and Chang 8 members sand bodies, and the diagenesis is the main factor controlling the densification of the reservoirs. Because of the difference in rock fabrics and the chlorite content of Chang 6 and Chang 8, the strong compaction resulted in less porosity reduction(17%) of the Chang 81 reservoir with larger buried depth and larger ground temperature than the Chang 63 reservoir(19%). The siliceous, calcareous and clay minerals cement filling the pores and blocking the pore throat, which is the key factor causing the big differences between the reservoir permeability of Chang 6 and Chang 8 members.
文摘In order to analyze the normal deviatoric stress that viscous-elastic fluid acting on the residual oil under the situation of different flooding conditions and different permeabilities, Viscous-elastic fluid flow equation is established in the micro pore by choosing the continuity equation, motion equation and the upper-convected Maxwell constitutive equation, the flow field is computed by using numerical analysis, the forces that driving fluid acting on the residual oil in micro pore are got, and the influence of flooding conditions, pore width and viscous-elasticity of driving fluid on force is compared and analyzed. The results show that: the more viscous-elasticity of driving fluid increases, the greater the normal deviatoric stress acting on the residual oil increases;using constant pressure gradient flooding, the lager the pore width is, the greater normal deviatoric stress acting on the residual oil will be.
文摘The Micro pore volume in porous materials usually interests many researchers. However, there has been few, if not, direct method to determine it. A strategy of combining mercury porosimetry with pre adsorption is proposed in the present paper. The total pore volume in activated carbon is determined through direct measurements for the first time. The application scope of mercury porosimetry is also enlarged. Besides, the present experiments also confirmed the preference of adsorption to the smaller pores even in the range of meso and macro pores.
基金supported by the National Natural Science Foundation of China(21633008,21433003,U1601211,21733004)National Science and Technology Major Project(2016YFB0101202)+1 种基金Jilin Province Science and Technology Development Program(20150101066JC,20160622037JC,20170203003SF,20170520150JH)Hundred Talents Program of Chinese Academy of Sciences and the Recruitment Program of Foreign Experts(WQ20122200077)
文摘Rational regulation on pore structure and active site density plays critical roles in enhancing the performance of Fe-N-C catalysts. As the microporous structure of the carbon substrate is generally regarded as the active site hosts, its hostility to electron/mass transfer could lead to the incomplete fulfillment of the catalytic activity. Besides, the formation of inactive metallic Fe particles during the conventional catalyst synthesis could also decrease the active site density and complicate the identification of real active site. Herein, we developed a facial hydrogen etching methodology to yield single site Fe-N-C catalysts featured with micro/mesoporous hierarchical structure. The hydrogen concentration in pyrolysis process was designated to effectively regulate the pore structure and active site density of the resulted catalysts.The optimized sample achieves excellent ORR catalytic performance with an ultralow H2O2 yield(1%)and superb stability over 10,000 cycles. Our finding provides new thoughts for the rational design of hierarchically porous carbon-based materials and highly promising non-precious metal ORR catalysts.
基金The authors would like to appreeiate the National Natural Science Foundation of China （51005180）, the Fok Ying-Tong Educalion Fuundalion for Young Teachers in the Higher Education Institutions of China （131052） , the Fundamental Research Fund of NPU（JC201233） , and the 111 Project of China （B08040）.
文摘Micro-pore is a very common material defect. In the present paper, the temperature fields of medium carbon steel joints with and without micro-pore defect during linear friction welding （LFW） were investigated by using finite element method. The effect of micro-pore defect on the axial shortening of joints during LFW was examined. The x- and y-direction displacements of micro-pore during the LFW process were also studied. In addition, the shape of micro-pore after LFW was observed. The heat conducted from the weld inteace to the specimen interior. The fluctuation range of the temperature curves for the joint with micro-pore is larger than that without micro-pore. Position of micro-pore changes with the change of the friction time. The circular shape of micro-pore becomes oval after welding.
基金Supported by the China National Science and Technology Major Project(2017ZX05063002-009)the National Natural Science Foundation of China(41772150)
文摘Based on scanning electron microscopy and nitrogen adsorption experiment at low temperature, the pore types and structures of the Longmaxi Formation shale in the Dianqianbei area, SW China were analyzed, and a molecular model was built. According to mathematical statistics, the validation of the model was solved by converting it into a mathematical formula. It is found by SEM that the pores in clay mineral layers and organic pores occupy most of the pores in shale; the nitrogen adsorption experiment at low temperature reveals that groove pores formed by flaky particles and micro-pores are the main types of pores, and the results of the two are in good agreement. A molecular model was established by illite and graphene molecular structures. Moreover, based on the fractal theory and the Frenkel-Halsey-Hill formula, a modified Frenkel-Halsey-Hill formula was proposed. The reliability of the molecular model was verified to some extent by obtaining parameters such as the fractal dimension, replacement rate and fractal coefficients of correction, and mathematical calculation. This study provides the theoretical basis for quantitative study of shale reservoirs.
文摘Micro-pored CA6 -MA lightweight material with CAM： MA mass ratio of 7：3 was prepared using Al（OH） 3, MgCO3 and CaCO3 as starting materials, and anthracite. sweet potato starch and anthracite ＋ sweet potato starch as pore forming agent （PFA） with an addition of 10 mass%, 20 mass% and 30 mass%, respectively. The starting materials were dry mixed, wet co-milled in a ball mill for 1 h. slip cast into cylindrical specimens with a diameter of 60 ram. and then calcined at 1 450 ℃ for 3 h. With the increase of PFA addition,, apparent porosity increases, and bulk density decreases. The influence of different PFAs on properties of the micro-pored LW CAM -MA aggregate was investigated. The achieved CAM - MA, by adding 30% sweet potato starch, has a porosity of 76. 8%, bulk density of 0. 78 g · cm^ - 3 and median pore size of 1.90 μm.
基金Funded by the National Basic Research Program of China(973 Program,2015CB655100)the Natural Science Foundation of China(Nos.51308111 and 51278098)+5 种基金the Industry-UniversityResearch Cooperative Innovation Fund of Jiangsu Province(No.BY2013091)the Research Project of Science and Technology Development of China Railway Corporation(No.2014G004-F)the“Six Talent Peak”Project of Jiangsu Province(No.2014-XCL-023 and 2016-XCL-196)the China Postdoctoral Science Foundation(No.2013M531249)the Postdoctoral Science Foundation of Jiangsu Province of China(1202008C)the Applied Research Foundation of Nantong City(No.BK2013001)
文摘A new low-cost corrosion-resistant rebar（HRB400 R） was designed and fabricated by chromium micro-alloying. The effects of Cr on the passivation and corrosion behavior of this rebar in the simulated concrete pore solutions were studied systematically, and its improved corrosion resistance was revealed. In the Cl--free saturated Ca（OH）_2 solution, the HRB400 R rebar presented nearly the same passive film and similar passivation ability compared to the common carbon steel rebar. In the long-term immersion corrosion test in the Cl--contained Ca（OH）_2 solution, the HRB400 R rebar presented improved corrosion resistance and obvious longer passivation-maintaining period. Micro-alloying of Cr element in the rebar matrix enhanced its corrosion resistance against Cl--attack and retarded the corrosion initiation in the matrix. In the alkaline Na Cl salt spraying test, the HRB400 R rebar also presented obviously lower mass-loss rate. The enrichment of Cr element in the rust layer improved its retardant effect to the penetration of aggressive medium, and decreased the corrosion propagation rate of the rebar.
文摘The microstructure of the RE silicide alloy was studied by SEM. The feature of the phase and the distribution of Ca, P, Al were analyzed, especially the distribution of micro-cracks and its composition were determined. The result demonstrates that only a few phosphides contribute to the spontaneous crumbling of the RE silicide alloy by reacting with water and forming oxide or phosphorus oxide. The phosphorus content is not the critical factor of disintegration in the alloy studied.
文摘The pressure-sensitive effect on the pore structure of sandstone was investigated using X-ray computed micro-tomography and QEMSCAN quantitative mineral analysis. In a physical simulation study, we extracted the pore network model from digital cores at different confining pressures and evaluated the effect of pressure sensitivity on the multiphase displacement process. In both the pore network model and QEMSCAN scanning, the pore structure was observed to be damaged under a high confining pressure. Due to their different scales, the pores and throats exhibited inhomogeneous changes; further, the throats exhibited a significant variation compared to that exhibited by the pores. Meanwhile, the heterogeneity of the pore structure under the two aforementioned activities was aggravated by the elastic-plastic deformation of the pore structure.The pressure-sensitive effect increased the proportion of mineral particles, such as quartz(the main component of the core skeleton), and reduced the proportion of clay minerals. The clay minerals were originally attached to the pore walls or interspersed in the pores; however, as the pressure increased, the clay minerals accumulated in the pores resulting in blockage of the pores. While simulating the multiphase displacement process, increasing the confining pressure was observed to severely restrict the flowability of oil and water. This study promises to improve the efficiency of reservoir development in terms of oil and gas exploitation.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB1002010)the Major Program for the Fundamental Research of Shanghai Committee of Science and Technology(No.12JC1410400)the National Natural Science Foundation of China for Distinguished Young Scholars(No.41325016)
文摘Microstructure of shale formation is the key to understanding its petrophysical and chemical properties.Optical microscopy, scanning electron microscopy and micro-computed tomography(μ-CT) have been combined for characterization of microstructure of Longmaxi(LMX)shale from Shizhu area, Sichan Basin. The results indicate that laminated LMX shale consists of mineral matrix-rich layers and organic matter(OM)-rich layers at micrometer scale in two and three dimensions. Mineral matrix layers,mainly consisting of interparticle pores and intraplatelet pores, are approximately parallel to the bedding plane.Pyrite-rich layer, mainly containing intercrystalline pores,shows a strong preferred orientation parallel to the bedding plane. OM-rich layer, mainly containing OM pores, seems to be discontinuous. In addition, intercrystalline pores are enriched in some layers, while OM pores are distributed irregularly in matrix layers. This vertical heterogeneity of pore microscopic structures in LMX shale is of great importance to understand its petrophysical and chemical properties.
基金Projects(50436010, 50605023, 50675070) supported by the National Natural Science Foundation of ChinaProject(04105942) supported by the Natural Science Foundation of Guangdong Province, China
文摘Using ploughing-extrusion method, a cross-connected finned micro-grooves structure was formed on the surface of copper strips with thickness of 0.4 mm. The structure was fabricated by making ‘V’-grooves in copper strips and perpendicular ‘V’-grooves on the opposite side that intersect the first set of grooves. Micro pores appear at the intersection of these cross-connected grooves, and micro fins appear on the groove fringes. So it can be defined as ‘pore-groove-fin’ structure. The preferable ‘pore-groove-fin’ structure can be obtained under the condition that the tool edge inclination angle (χγ) is 45°, both the major extrusion angle (γo) and the minor extrusion angle (γ 0′ ) are 30°, both the major formation angle (β) and the minor formation angle (β′) are 10°, the ploughing-extrusion depth (fd) is 0.32 mm and the groove pitch is 0.4 mm on surfaces A and B. The formed included angle of groove A is 70°, and the groove depth is 0.3 mm, while the included angle of opposite perpendicular groove B is 20° with the groove depth of 0.35 mm. The obtained fin height is 0.15 mm, the elliptical pore length is 0.2 mm and the width is 0.05 mm. Experiments show that fd has the greatest influence on the formation of micro pores. Bulges appear on the opposite surface B when the ploughing-extrusion depth on surface A (fdA) reaches a critical value. The ploughing-extrusion depth on surface B (fdB) has great influence on the re-growth of fin structure.
基金Science Found for Distinguished Yong Scholars of Heilongjiang Province(JC200901)Fundamental Research Funds for the Central Universities Project(HIT.NSRIF.2009030)Program of Excellent Team at Harbin Institute of Technology
文摘Recently a new kind stent,porous drug-eluting stent,has been developed to overcome the problems of bare metal stent(BMS)and drug-eluting stent(DES),and the clinic results reveal that it combined the advantage of BMS and DES.In this paper,a new method to fabricate surface pores on 316L stainless steel stent using anodic oxidation of aluminum mask film deposited by magnetron sputtering on 316L substrate was reported.The effect of experimental parameters,such as anodization time,anodization voltage,anodization solution and anodization temperature,on the pores'size distribution and density are investigated using SEM.It is found that the pores characterizations strongly depend on anodization time and pores expanding rate through AAO films and on stainless steel surface.
文摘A novel process for fabricating an in-situ micro-porous on 316 L stainless steel was described.Aluminum films about 0.7-1.4 m in thickness were deposited on 316 L stainless steel surface by magnetron sputtering.The films were then anodized in 0.3 M oxalic acid.Through appropriate chemical dissolution,the alumina film was removed and the underlying micro-porous 316 L with diameters ranging from 500 nm to 2.4m was obtained.The morphology of the porous 316 L surface was examined by scanning electron microscope.The results indicate that the thickness of aluminum films and the anodizing potential have a combined action on the formation of porous structure on 316 L surface.Then anodic current density could be affected evidently by the film thickness.The pores size increases obviously with the increasing of the anodizing potential,when the thickness of aluminum film was about 1.4m.
