In-situ upgrading by heating is feasible for low-maturity shale oil,where the pore space dynamically evolves.We characterize this response for a heated substrate concurrently imaged by SEM.We systematically follow the...In-situ upgrading by heating is feasible for low-maturity shale oil,where the pore space dynamically evolves.We characterize this response for a heated substrate concurrently imaged by SEM.We systematically follow the evolution of pore quantity,size(length,width and cross-sectional area),orientation,shape(aspect ratio,roundness and solidity)and their anisotropy—interpreted by machine learning.Results indicate that heating generates new pores in both organic matter and inorganic minerals.However,the newly formed pores are smaller than the original pores and thus reduce average lengths and widths of the bedding-parallel pore system.Conversely,the average pore lengths and widths are increased in the bedding-perpendicular direction.Besides,heating increases the cross-sectional area of pores in low-maturity oil shales,where this growth tendency fluctuates at<300℃ but becomes steady at>300℃.In addition,the orientation and shape of the newly-formed heating-induced pores follow the habit of the original pores and follow the initial probability distributions of pore orientation and shape.Herein,limited anisotropy is detected in pore direction and shape,indicating similar modes of evolution both bedding-parallel and bedding-normal.We propose a straightforward but robust model to describe evolution of pore system in low-maturity oil shales during heating.展开更多
Ferrospheres in fly ashes from a coal-fired power plant were extracted by a magnetic separation technique and their microstructure was studied by scanning electron microscopy (SEM), energy dispersive X-ray analysis (E...Ferrospheres in fly ashes from a coal-fired power plant were extracted by a magnetic separation technique and their microstructure was studied by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and environmental scanning electron microscopy (ESEM). Ferrospheres in fly ashes show significant iron enrichment compared to their respective fly ashes. Iron oxides in ferrospheres mainly occur as minerals magnetite (Fe3O4) and hematite (α-Fe2O3), which are derived mainly from the decomposition and oxidation of iron-bearing minerals in coal during combustion. EDX data indicate that ferrospheres also contain Si, S, Al and Ca resulting from quartz, mullite, anhydrite and amorphous materials. A large percentage of ferrospheres are commonly 5～50 μm in size. The microstructure of ferrospheres includes smooth, polygonal, dendritic, granular and molten drop characteristics. SEM coupled with EDX provided fast and accurate results of the microstructure and chemical composition of ferrospheres, and helped us to assess environmental issues related to the disposal and utilization of fly ashes.展开更多
Ground failure is a major contributor to fatalities in underground mines in the US.Underground coal mines in the Northern Appalachian have weak roof rock composed of shale,which is prone to failure under high horizont...Ground failure is a major contributor to fatalities in underground mines in the US.Underground coal mines in the Northern Appalachian have weak roof rock composed of shale,which is prone to failure under high horizontal stress.Understanding the relationship among strength,specimen size and rock petrographic parameters is essential for developing an effective ground control plan.Size effect studies have found that rock strength varies with specimen size.This paper attempts to understand this strength variation using three specimen sizes(254-mm,508-mm,and 762-mm).The specimen strength was measured and the major petrographic parameters affecting the strength,namely grain size,grain shape,quartz content,clay content,etc.were analyzed using X-ray diffraction(XRD)and scanning electron microscopy(SEM).The petrographic parameters were then correlated with the strength of the three differently sized specimens.The results showed that 508-mm specimen had the lowest strength.Quartz content of the 508-mm specimen was lower than that of 254-mm and 762-mm specimens.Clay content and average grain size of the 508-mm specimen were higher than those of 254-mm and 762-mm specimens.These results clearly show that grain size,quartz content and clay content contribute to strength variation observed in differently sized shale specimens.展开更多
In order to investigate the distribution of Cu and Mg, and the effect of Cu on the microstructure of steels, manganese steels containing various Cu contents were annealed at 1260, 1100 and 1000℃, respectively, for I ...In order to investigate the distribution of Cu and Mg, and the effect of Cu on the microstructure of steels, manganese steels containing various Cu contents were annealed at 1260, 1100 and 1000℃, respectively, for I h and subsequently cooled to room temperature in the furnace to simulate the pre-rolling anneal. The results indicate that Cu is not microscopically segregated in the annealed steels. The scanning electron microscopy （SEM） observation shows that the main microstructure consist of ferrite and pearlite; the percentage of pearlite in the steels increases with increasing Cu content. The grain size reduces with the decrease of the annealing temperature. The results of energy dispersive X-ray analysis （EDXA） suggest that Cu content in pearlite is higher than that in ferrite, demonstrating that the microstructure-segregation of Cu occurred. However, the cast specimens show that Cu content in MnS and S-rich phases is high. In addition, Cu of 0.2%-0.4% could improve the distribution of MnS and S-rich inclusions. The optimal Cu content in steels and the optimal annealing temperature between 1100-1200℃ were determined.展开更多
This study was conducted to clarify the distribution and morphology of free neuromasts during the development of half-smooth tongue sole （Cynoglossus semilaevis） using scanning electron microscopy. During developmen...This study was conducted to clarify the distribution and morphology of free neuromasts during the development of half-smooth tongue sole （Cynoglossus semilaevis） using scanning electron microscopy. During development, （1） the apical surface of free neuromasts changed in shape from a circle to a four-poiut star; （2） the external structure changed from being level with the epidermis to papilla-like above the level of the epidermis; （3） the neuromast cupula changed from cylindrical to blade-shaped; （4） the free neuromasts went from occurring singly to being in clusters of a few single organs; （5） the arrangement changed from a linear array to no discernable pattern; （6） there was a significant increase in the number of free neuromasts after metamorphosis. In adult C. semilaevis, free neuromasts were only observed on the abocular side of the head. Thus, there were more free neuromasts located on the abocular side of the head with a higher concentration around the anterior nostril and mouth, which may have a mechanical sensory function to help locate food as an adaptation to a benthic mode of life.展开更多
The utility of GIS （geographic information system） methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X...The utility of GIS （geographic information system） methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X-ray techniques and SEM （scanning electron microscopy）. The elemental neighborhood associations of a single element, P （phosphorus）, were quantified at a magnification of 3,000 ×. For each of the 170,000 pixels on the images which displayed a strong P concentration, neighborhoods from 0.1μm^2 to 12 μm^2 were examined for associated elemental concentrations. PCA （principal component analysis） revealed two significant neighborhood types associated with P in samples of pH 4, and three neighborhood types at pH 8. These neighborhoods corresponded to Mg-P associations commonly found to be chemically prevalent in river sediments impacted by agricultural operations. Discriminant analysis showed that the greatest accuracy in predicting sample pH could be achieved by using a neighborhood size of 12 ~m2. Potassium at relatively large neighborhood sizes was the element most significant in predicting pH. While many of the chemical associations in close proximity to P could be predicted and explained through mineral solubility, spatial analysis provided some interesting insights into the structure of the samples. Results also indicted differences in the spatial scale associated with different processes.展开更多
Micrcostructures of bulk and thin film YBa_2Cu_3O_(7-δ) superconductors were studied by using scanning elec-tron microscopy (SEM). It was confirmed that viscous technique processed bulk YBa_2Cu_3O_(7-δ) has a homoge...Micrcostructures of bulk and thin film YBa_2Cu_3O_(7-δ) superconductors were studied by using scanning elec-tron microscopy (SEM). It was confirmed that viscous technique processed bulk YBa_2Cu_3O_(7-δ) has a homoge-neous microstructure across the pellet diameter. Concerning the thin film, it was found that 2 ￣H￣+ ion implanta-tion with a dose of 1× 10￣(12)cm￣(-2) at 50 keV does not cause microstructural change of the film at a micrometrelevel. Combined with previous studies by using high resolution transmission electron microscopy, it appearsthat the structural modification is at an atomic scale.展开更多
Common bean (Phaseolus vulgaris L.) is an economic important crop and one of the major grain legumes for human consumption in Latin America, Africa and Asia. A morphological study of shoot induced from embryonic axes ...Common bean (Phaseolus vulgaris L.) is an economic important crop and one of the major grain legumes for human consumption in Latin America, Africa and Asia. A morphological study of shoot induced from embryonic axes development in four Costa Rican bean varieties (Brunca, Huetar, Guaymi and Bribri) cultivated on MS media with or without 5 mg·L–1 de N6-benzylaminopurine (BAP) by scanning electron microscopy (SEM) was developed in the present work. Micrographs showed similarities and differences in the ultrastructure of the apical dome, epidermal surface, stomata and different types of trichomes in the varieties cultivated on organogenesis media. Genotypes with advantageous morphological characteristics for genetic transformation, in particular an exposed apical dome, were identified. This work will contribute to the optimization of the in vitro regeneration of four common bean varieties.展开更多
基金financially supported by the National Key Research and Development Program of China(Grant No.2022YFE0129800)the National Natural Science Foundation of China(Grant No.42202204)。
文摘In-situ upgrading by heating is feasible for low-maturity shale oil,where the pore space dynamically evolves.We characterize this response for a heated substrate concurrently imaged by SEM.We systematically follow the evolution of pore quantity,size(length,width and cross-sectional area),orientation,shape(aspect ratio,roundness and solidity)and their anisotropy—interpreted by machine learning.Results indicate that heating generates new pores in both organic matter and inorganic minerals.However,the newly formed pores are smaller than the original pores and thus reduce average lengths and widths of the bedding-parallel pore system.Conversely,the average pore lengths and widths are increased in the bedding-perpendicular direction.Besides,heating increases the cross-sectional area of pores in low-maturity oil shales,where this growth tendency fluctuates at<300℃ but becomes steady at>300℃.In addition,the orientation and shape of the newly-formed heating-induced pores follow the habit of the original pores and follow the initial probability distributions of pore orientation and shape.Herein,limited anisotropy is detected in pore direction and shape,indicating similar modes of evolution both bedding-parallel and bedding-normal.We propose a straightforward but robust model to describe evolution of pore system in low-maturity oil shales during heating.
基金Project supported by the National Natural Science Foundation of China (No. 40771096)the Natural Science Foundation of Zhejiang Province (No. R305078), China
文摘Ferrospheres in fly ashes from a coal-fired power plant were extracted by a magnetic separation technique and their microstructure was studied by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and environmental scanning electron microscopy (ESEM). Ferrospheres in fly ashes show significant iron enrichment compared to their respective fly ashes. Iron oxides in ferrospheres mainly occur as minerals magnetite (Fe3O4) and hematite (α-Fe2O3), which are derived mainly from the decomposition and oxidation of iron-bearing minerals in coal during combustion. EDX data indicate that ferrospheres also contain Si, S, Al and Ca resulting from quartz, mullite, anhydrite and amorphous materials. A large percentage of ferrospheres are commonly 5～50 μm in size. The microstructure of ferrospheres includes smooth, polygonal, dendritic, granular and molten drop characteristics. SEM coupled with EDX provided fast and accurate results of the microstructure and chemical composition of ferrospheres, and helped us to assess environmental issues related to the disposal and utilization of fly ashes.
文摘Ground failure is a major contributor to fatalities in underground mines in the US.Underground coal mines in the Northern Appalachian have weak roof rock composed of shale,which is prone to failure under high horizontal stress.Understanding the relationship among strength,specimen size and rock petrographic parameters is essential for developing an effective ground control plan.Size effect studies have found that rock strength varies with specimen size.This paper attempts to understand this strength variation using three specimen sizes(254-mm,508-mm,and 762-mm).The specimen strength was measured and the major petrographic parameters affecting the strength,namely grain size,grain shape,quartz content,clay content,etc.were analyzed using X-ray diffraction(XRD)and scanning electron microscopy(SEM).The petrographic parameters were then correlated with the strength of the three differently sized specimens.The results showed that 508-mm specimen had the lowest strength.Quartz content of the 508-mm specimen was lower than that of 254-mm and 762-mm specimens.Clay content and average grain size of the 508-mm specimen were higher than those of 254-mm and 762-mm specimens.These results clearly show that grain size,quartz content and clay content contribute to strength variation observed in differently sized shale specimens.
基金the Major Program of National Natural Science Foundation of China （No. 50499336） National Basic Research Program of China （No. 2004CB619101）.
文摘In order to investigate the distribution of Cu and Mg, and the effect of Cu on the microstructure of steels, manganese steels containing various Cu contents were annealed at 1260, 1100 and 1000℃, respectively, for I h and subsequently cooled to room temperature in the furnace to simulate the pre-rolling anneal. The results indicate that Cu is not microscopically segregated in the annealed steels. The scanning electron microscopy （SEM） observation shows that the main microstructure consist of ferrite and pearlite; the percentage of pearlite in the steels increases with increasing Cu content. The grain size reduces with the decrease of the annealing temperature. The results of energy dispersive X-ray analysis （EDXA） suggest that Cu content in pearlite is higher than that in ferrite, demonstrating that the microstructure-segregation of Cu occurred. However, the cast specimens show that Cu content in MnS and S-rich phases is high. In addition, Cu of 0.2%-0.4% could improve the distribution of MnS and S-rich inclusions. The optimal Cu content in steels and the optimal annealing temperature between 1100-1200℃ were determined.
基金Supported by the earmarked fund for Modem Agro-Industry Technology Research System(CARS-50-G01)the Fund for Outstanding Talents and Innovative Team of Agricultural Scientific Research,the Qingdao Natural Science Foundation(No.12-1-4-12-(1)-jch)the Research Fund for the Postgraduate of Shanghai Ocean University(No.A1-0209-14-0900-5)
文摘This study was conducted to clarify the distribution and morphology of free neuromasts during the development of half-smooth tongue sole （Cynoglossus semilaevis） using scanning electron microscopy. During development, （1） the apical surface of free neuromasts changed in shape from a circle to a four-poiut star; （2） the external structure changed from being level with the epidermis to papilla-like above the level of the epidermis; （3） the neuromast cupula changed from cylindrical to blade-shaped; （4） the free neuromasts went from occurring singly to being in clusters of a few single organs; （5） the arrangement changed from a linear array to no discernable pattern; （6） there was a significant increase in the number of free neuromasts after metamorphosis. In adult C. semilaevis, free neuromasts were only observed on the abocular side of the head. Thus, there were more free neuromasts located on the abocular side of the head with a higher concentration around the anterior nostril and mouth, which may have a mechanical sensory function to help locate food as an adaptation to a benthic mode of life.
文摘The utility of GIS （geographic information system） methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X-ray techniques and SEM （scanning electron microscopy）. The elemental neighborhood associations of a single element, P （phosphorus）, were quantified at a magnification of 3,000 ×. For each of the 170,000 pixels on the images which displayed a strong P concentration, neighborhoods from 0.1μm^2 to 12 μm^2 were examined for associated elemental concentrations. PCA （principal component analysis） revealed two significant neighborhood types associated with P in samples of pH 4, and three neighborhood types at pH 8. These neighborhoods corresponded to Mg-P associations commonly found to be chemically prevalent in river sediments impacted by agricultural operations. Discriminant analysis showed that the greatest accuracy in predicting sample pH could be achieved by using a neighborhood size of 12 ~m2. Potassium at relatively large neighborhood sizes was the element most significant in predicting pH. While many of the chemical associations in close proximity to P could be predicted and explained through mineral solubility, spatial analysis provided some interesting insights into the structure of the samples. Results also indicted differences in the spatial scale associated with different processes.
文摘Micrcostructures of bulk and thin film YBa_2Cu_3O_(7-δ) superconductors were studied by using scanning elec-tron microscopy (SEM). It was confirmed that viscous technique processed bulk YBa_2Cu_3O_(7-δ) has a homoge-neous microstructure across the pellet diameter. Concerning the thin film, it was found that 2 ￣H￣+ ion implanta-tion with a dose of 1× 10￣(12)cm￣(-2) at 50 keV does not cause microstructural change of the film at a micrometrelevel. Combined with previous studies by using high resolution transmission electron microscopy, it appearsthat the structural modification is at an atomic scale.
文摘Common bean (Phaseolus vulgaris L.) is an economic important crop and one of the major grain legumes for human consumption in Latin America, Africa and Asia. A morphological study of shoot induced from embryonic axes development in four Costa Rican bean varieties (Brunca, Huetar, Guaymi and Bribri) cultivated on MS media with or without 5 mg·L–1 de N6-benzylaminopurine (BAP) by scanning electron microscopy (SEM) was developed in the present work. Micrographs showed similarities and differences in the ultrastructure of the apical dome, epidermal surface, stomata and different types of trichomes in the varieties cultivated on organogenesis media. Genotypes with advantageous morphological characteristics for genetic transformation, in particular an exposed apical dome, were identified. This work will contribute to the optimization of the in vitro regeneration of four common bean varieties.
