Microstructure of the eco-material combining vegetation recovery with slope protection is important for determining plant-growing properties.Several techniques for analyzing the eco-material microstructure are present...Microstructure of the eco-material combining vegetation recovery with slope protection is important for determining plant-growing properties.Several techniques for analyzing the eco-material microstructure are presented,including the freeze-cut-drying method of preparing samples for scanning electronic microscopy (SEM),the SEM image processing technique and quantifying analysis method of the SEM images,and etc.The aggregates and pores in SEM images are identified using the different mathematics operators,and their effects are compared.The areas of aggregates and pores are obtained using the operator of morphology,and the influences of different thresholds in image segmentation are also discussed.The results show that the method,in which the variation of non-maximum grey-level gradient is limited,improves the effect of edge detections due to a weak distinction existing at the edge between the aggregates and pores in image.The determination of the threshold should combine the image characteristic with filling operation,so as to assure the precision of the image analysis,in which the contact-segmentation is the simplest and most effective method.The results also show that the pore areas in eco-materials are generally larger than those in the correlative soils,and their increment is large as soil fabric being fine.These differences are related to admixture of expansive perlitic.The operator of morphology provides a new method for the image analysis of other porous material microstructure such as soils and concretes.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
An historical collection of more than one hundred samples of minerals and ore, used in the second half of the XVIII century was found and acquired during Munich Mineralientage 2014. The samples contained in numbered g...An historical collection of more than one hundred samples of minerals and ore, used in the second half of the XVIII century was found and acquired during Munich Mineralientage 2014. The samples contained in numbered glass vials but lacking description, were prepared for teaching purpose about determinative mineralogy and ore recognition. All samples were analysed and identified. The identification effort drove the authors along a historical excursus about the didactics of mineralogy and the dry method analysis, nowadays neglected.展开更多
In precision machining processes such as grinding,for example,analysis of machined surface is important one of most parameters to evaluate process performance.Equally important is to perform tribological analysis to u...In precision machining processes such as grinding,for example,analysis of machined surface is important one of most parameters to evaluate process performance.Equally important is to perform tribological analysis to understand chip formation and abrasive wheel wear,thus enabling manufacturing of components free of thermal damages.In grinding,due to high hardness of abrasive grains that remove material from workpiece in chip form and very low values of radial depth of cut,combination of low roughness values and tight dimensional tolerances is attained.Accordingly,the parameters involved in this process are determinant in surface quality that is primarily evaluated in terms of surface roughness and workpiece functionality.In this work,surface roughness(Rt parameter)and scanning electron microscope(SEM)images of ground surfaces of the AISI 420 martensitic stainless steel samples were evaluated.Tests were carried out in surface grinding with a white aluminum oxide wheel and an environmentally-friendly semisynthetic water-soluble coolant.Two values of radial depth of cut(10μm and 25μm)were tested.The results showed that the highest roughness values,deeper grooves on the machined surfaces as well as poorer surface quality were obtained after grinding under the severest cutting conditions.展开更多
Super plasticizer was synthesized by using coal coking by product washing oil and industrial naphthalene. The results show that sulfonationt time （2.5 h）, sulfonation temperature （160 ℃） and condensation time （5...Super plasticizer was synthesized by using coal coking by product washing oil and industrial naphthalene. The results show that sulfonationt time （2.5 h）, sulfonation temperature （160 ℃） and condensation time （5.0 h） are key factors. Adding oxidizing agent MO in the course of synthesis can decrease the emission of SO2 in exhaust （20%）. Compared with NF, NF-30 have some advantages in lower cost, high water reducing rate （19.7%） and optimum early strengths. Moreover, TGA-DTA and SEM analysis were adopted to research the NF-30 modified concrete on hydyation mechanism. The analysis show that, compared with NF, there are a large number of hydration products such as Ca （OH）2, C-S-H, AFt etc of NF-30, the structure of NF-30 is dense and the performance is good.展开更多
文摘Microstructure of the eco-material combining vegetation recovery with slope protection is important for determining plant-growing properties.Several techniques for analyzing the eco-material microstructure are presented,including the freeze-cut-drying method of preparing samples for scanning electronic microscopy (SEM),the SEM image processing technique and quantifying analysis method of the SEM images,and etc.The aggregates and pores in SEM images are identified using the different mathematics operators,and their effects are compared.The areas of aggregates and pores are obtained using the operator of morphology,and the influences of different thresholds in image segmentation are also discussed.The results show that the method,in which the variation of non-maximum grey-level gradient is limited,improves the effect of edge detections due to a weak distinction existing at the edge between the aggregates and pores in image.The determination of the threshold should combine the image characteristic with filling operation,so as to assure the precision of the image analysis,in which the contact-segmentation is the simplest and most effective method.The results also show that the pore areas in eco-materials are generally larger than those in the correlative soils,and their increment is large as soil fabric being fine.These differences are related to admixture of expansive perlitic.The operator of morphology provides a new method for the image analysis of other porous material microstructure such as soils and concretes.
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An historical collection of more than one hundred samples of minerals and ore, used in the second half of the XVIII century was found and acquired during Munich Mineralientage 2014. The samples contained in numbered glass vials but lacking description, were prepared for teaching purpose about determinative mineralogy and ore recognition. All samples were analysed and identified. The identification effort drove the authors along a historical excursus about the didactics of mineralogy and the dry method analysis, nowadays neglected.
文摘In precision machining processes such as grinding,for example,analysis of machined surface is important one of most parameters to evaluate process performance.Equally important is to perform tribological analysis to understand chip formation and abrasive wheel wear,thus enabling manufacturing of components free of thermal damages.In grinding,due to high hardness of abrasive grains that remove material from workpiece in chip form and very low values of radial depth of cut,combination of low roughness values and tight dimensional tolerances is attained.Accordingly,the parameters involved in this process are determinant in surface quality that is primarily evaluated in terms of surface roughness and workpiece functionality.In this work,surface roughness(Rt parameter)and scanning electron microscope(SEM)images of ground surfaces of the AISI 420 martensitic stainless steel samples were evaluated.Tests were carried out in surface grinding with a white aluminum oxide wheel and an environmentally-friendly semisynthetic water-soluble coolant.Two values of radial depth of cut(10μm and 25μm)were tested.The results showed that the highest roughness values,deeper grooves on the machined surfaces as well as poorer surface quality were obtained after grinding under the severest cutting conditions.
基金Funded by the National Natural Science Foundation of China(No.51175004)Educational Commission of Anhui Province of China(No.KJ2012A078)
文摘Super plasticizer was synthesized by using coal coking by product washing oil and industrial naphthalene. The results show that sulfonationt time （2.5 h）, sulfonation temperature （160 ℃） and condensation time （5.0 h） are key factors. Adding oxidizing agent MO in the course of synthesis can decrease the emission of SO2 in exhaust （20%）. Compared with NF, NF-30 have some advantages in lower cost, high water reducing rate （19.7%） and optimum early strengths. Moreover, TGA-DTA and SEM analysis were adopted to research the NF-30 modified concrete on hydyation mechanism. The analysis show that, compared with NF, there are a large number of hydration products such as Ca （OH）2, C-S-H, AFt etc of NF-30, the structure of NF-30 is dense and the performance is good.
