Watershed segmentation is sensitive to noises and irregular details within the image,which frequently leads to a serious over-segmentation Linear filtering before watershed segmentation can reduce over-segmentation to...Watershed segmentation is sensitive to noises and irregular details within the image,which frequently leads to a serious over-segmentation Linear filtering before watershed segmentation can reduce over-segmentation to some extent,however,it often causes the position offset of object contours.For the purpose of reducing over-segmentation to preserve the location of object contours,the watershed segmentation based on the hierarchical multi-scale modification of morphological gradient is proposed.Firstly,multi-scale morphological filtering was employed to smooth the original image.Then,the gradient image was divided into multi-levels by the volume of three-dimension topographic relief,where the lower gradient layers were further modifiedby morphological closing with larger-sized structuring-elements,and the higher layers with the smaller one.In this way,most local minimums caused by irregular details and noises can be removed,while region contour positions corresponding to the target area were largely preserved.Finally,morphological watershed algorithm was employed to implement segmentation on the modified gradient image.The experimental results show that the proposed method can greatly reduce the over-segmentation of the watershed and avoid the position offset of the object contours.展开更多
A scheme based on irregular V-shaped silicon nanoantennas is proposed to optimize transverse unidirectional scattering under plane wave irradiation.Traditional methods of designing regular shapes offer fewer parameter...A scheme based on irregular V-shaped silicon nanoantennas is proposed to optimize transverse unidirectional scattering under plane wave irradiation.Traditional methods of designing regular shapes offer fewer parameters and higher search efficiency.However,due to the limitations of regular shapes,it is challenging to meet high-precision design requirements.Irregular shape design allows for a broader range of adjustments,but the complexity of shape parameters leads to lower search efficiency and a higher likelihood of converging to local optima.展开更多
This paper introduces a multi-scale morphological edge detection algorithm to extract SAR image edge which suffers seriously from noise. Combining the basic theme of morphology with that of multi-scale analysis, the a...This paper introduces a multi-scale morphological edge detection algorithm to extract SAR image edge which suffers seriously from noise. Combining the basic theme of morphology with that of multi-scale analysis, the algorithm presents the outstanding characteristics of accuracy and robustness. Comparative Experiments reveal its fine performance.展开更多
We observed morphological modification of rod-shaped C60 solvate crystals using a facile hydrothermal method.The initial C60 rods were changed from smooth rods to rough rods,porous rods or pieces under different hydro...We observed morphological modification of rod-shaped C60 solvate crystals using a facile hydrothermal method.The initial C60 rods were changed from smooth rods to rough rods,porous rods or pieces under different hydrothermal conditions.During the hydrothermal treatment,the initial samples underwent a decomposition-recrystallization process,which can be tuned by the content of alcohol in the hydrothermal solution,thereby leading to modification of the morphological properties of the initial C60 rods.In addition,the rough and porous C60 rods prepared in our work exhibit excellent photoluminescence intensities that are approximately 7 and 3 times higher than those of pure C60 powders,respectively.Our results suggest that the hydrothermal method is a potential route for fabricating fullerene materials with controllable morphologies and novel functions.展开更多
Working conditions of rolling bearings of wind turbine generators are complicated, and their vibration signals often show non-linear and non-stationary characteristics. In order to improve the efficiency of feature ex...Working conditions of rolling bearings of wind turbine generators are complicated, and their vibration signals often show non-linear and non-stationary characteristics. In order to improve the efficiency of feature extraction of wind turbine rolling bearings and to strengthen the feature information, a new structural element and an adaptive algorithm based on the peak energy are proposed,which are combined with spectral correlation analysis to form a fault diagnosis algorithm for wind turbine rolling bearings. The proposed method firstly addresses the problem of impulsive signal omissions that are prone to occur in the process of fault feature extraction of traditional structural elements and proposes a "W" structural element to capture more characteristic information. Then, the proposed method selects the scale of multi-scale mathematical morphology, aiming at the problem of multi-scale mathematical morphology scale selection and structural element expansion law. An adaptive algorithm based on peak energy is proposed to carry out morphological scale selection and structural element expansion by improving the computing efficiency and enhancing the feature extraction effect.Finally, the proposed method performs spectral correlation analysis in the frequency domain for an unknown signal of the extracted feature and identifies the fault based on the correlation coefficient. The method is verified by numerical examples using experimental rig bearing data and actual wind field acquisition data and compared with traditional triangular and flat structural elements. The experimental results show that the new structural elements can more effectively extract the pulses in the signal and reduce noise interference,and the fault-diagnosis algorithm can accurately identify the fault category and improve the reliability of the results.展开更多
The features of alkali activated slag（AAS） and portland cement （PC） were observed on multi-scale,the crack and fracture sections were observed with naked eyes,and SEM and AFM were used to study the structure morph...The features of alkali activated slag（AAS） and portland cement （PC） were observed on multi-scale,the crack and fracture sections were observed with naked eyes,and SEM and AFM were used to study the structure morphology differences between PC and AAS on micrometer to nano meter scale.The experimental results indicated that the AAS paste had soil like fracture texture and it was composed of mainly C-S-H gel but lacks of crystals,and it had a very strong tendency to shrink and crack.AAS paste is much denser and more homogeneous than PC,and on the nano scale C-S-H nano particle in the AAS paste is much smaller and packs much denser than PC paste.展开更多
Seismic energy decays while propagating subsurface, which may reduce the resolution of seismic data. This paper studies the method of seismic energy dispersion compensation which provides the basic principles for mult...Seismic energy decays while propagating subsurface, which may reduce the resolution of seismic data. This paper studies the method of seismic energy dispersion compensation which provides the basic principles for multi-scale morphology and the spectrum simulation method. These methods are applied in seismic energy compensation. First of all, the seismic data is decomposed into multiple scales and the effective frequency bandwidth is selectively broadened for some scales by using a spectrum simulation method. In this process, according to the amplitude spectrum of each scale, the best simulation range is selected to simulate the middle and low frequency components to ensure the authenticity of the simulation curve which is calculated by the median method, and the high frequency component is broadened. Finally, these scales are reconstructed with reasonable coefficients, and the compensated seismic data can be obtained. Examples are shown to illustrate the feasibility of the energy compensation method.展开更多
Being used more and more widely in engineering,AlSi alloys comprise about 80%of all kinds of aluminum alloys,which are the most widely utilized nonferrous alloys.Although most Al-Si alloys consist of multiple componen...Being used more and more widely in engineering,AlSi alloys comprise about 80%of all kinds of aluminum alloys,which are the most widely utilized nonferrous alloys.Although most Al-Si alloys consist of multiple components,the eutectics in the structure accounts for 50%-90%of the sum volume of such alloys.Therefore,understanding the modification mechanism and function rules of the AlSi eutectic solidification is the technical key in controlling the structures and properties of such casting alloys.The present paper chiefly reviews recent investigation developments and important conclusions along the lines of the functions of modification elements and their modification mechanism in the eutectic solidification of Al-Si alloys.展开更多
Trace amount of Sr(0.05 wt.%)was added into the hypoeutectic Al−Si(3−12 wt.%Si)alloys to modify their microstructure and improve thermal conductivity.The results showed that the thermal conductivity of hypoeutectic Al...Trace amount of Sr(0.05 wt.%)was added into the hypoeutectic Al−Si(3−12 wt.%Si)alloys to modify their microstructure and improve thermal conductivity.The results showed that the thermal conductivity of hypoeutectic Al−Si alloys was improved by Sr modification,and the increment and increasing rate of the thermal conductivity gradually increased with Si content increasing.The improvement of thermal conductivity was primarily related to the morphology variation of eutectic Si phases.In Sr-modified Al−Si alloys,the morphology of eutectic Si phases was a mixed morphology of fiber structure and fine flaky structure,and the proportion of the fine flaky eutectic Si phases gradually decreased with Si content increasing.Under the Si content reaching 9 wt.%,the proportion of fine flaky eutectic Si phases was nearly negligible in Sr-modified alloys.Correspondingly,the increment and increasing rate of thermal conductivity of Sr-modified alloys reached the maximum and tended to be stable.展开更多
The effects of calcination and modification on the morphology （shapes and textures） and crystal structure of anhydrite powders were studied. The results show that, calcination at 100℃ causes anhydrite to disintegra...The effects of calcination and modification on the morphology （shapes and textures） and crystal structure of anhydrite powders were studied. The results show that, calcination at 100℃ causes anhydrite to disintegrate into smaller crystals, accompanied by a slight in- crease in d-spacing. Without calcination and modification, the solidification time and curing time of anhydrite are 15 and 77 h, respectively. After the treatment, however, the solidification time and curing time are shortened significantly to 9.5 and 14 rain, respectively. The com- pressive and flexural strengths of hydration products made from the treated anhydrite reach 10.2 and 2.0 MPa, respectively. The much shorter solidification and curing time make it possible to use anhydrite as a building and construction material.展开更多
The morphological and compositional changes of the PP fibers pretreated with dielectric barrier discharge (DBD)are investigated with SEM, XPS and IR. The result shows that the etching effect is the main reason for the...The morphological and compositional changes of the PP fibers pretreated with dielectric barrier discharge (DBD)are investigated with SEM, XPS and IR. The result shows that the etching effect is the main reason for the improvement of the result of pull-out test of the fibercement composite reported in a previous paper and the oxidation of the fiber surface also favors the adhesion between the fiber and the matrix.展开更多
In the present study, the structural modification of sand cast Al-12wt%Si alloy with sulfur/sodium and its effect on mechanical properties were investigated. Different addition levels of sulfur and sodium were used to...In the present study, the structural modification of sand cast Al-12wt%Si alloy with sulfur/sodium and its effect on mechanical properties were investigated. Different addition levels of sulfur and sodium were used to modify and produce castings of the same shape and size from the alloy. The results indicated that the addition of sodium or sulfur to eutectic Al-Si alloy can modify the Al-Si eutectic morphology from needle-like eutectic silicon structure to fine-scale eutectic silicon structure with significant improvement in mechanical properties of the alloy. The optimum levels of modification by sodium flux (60% NaF and 40% NaCl) and sulfur were found to be 0.6% - 1.0% and 0.02% - 0.05% of the weight of the alloy respectively. The alloy modified with 0.6% Na flux had the best mechanical properties closely followed by the one modified with 0.02% sulfur. Over modification of the alloy with sodium produced over modification band which consisted of aluminum dendrites and coarse silicon particles in the microstructure of the alloy. Increase in concentration of sulfur decreased the degree of fineness of the eutectic silicon structure with significant decrease in mechanical properties of the alloy and this is suggested to be as a result of the presence of a brittle sulfur compound at the grain interfaces of the alloy.展开更多
The high-frequency components in the traditional multi-scale transform method are approximately sparse, which can represent different information of the details. But in the low-frequency component, the coefficients ar...The high-frequency components in the traditional multi-scale transform method are approximately sparse, which can represent different information of the details. But in the low-frequency component, the coefficients around the zero value are very few, so we cannot sparsely represent low-frequency image information. The low-frequency component contains the main energy of the image and depicts the profile of the image. Direct fusion of the low-frequency component will not be conducive to obtain highly accurate fusion result. Therefore, this paper presents an infrared and visible image fusion method combining the multi-scale and top-hat transforms. On one hand, the new top-hat-transform can effectively extract the salient features of the low-frequency component. On the other hand, the multi-scale transform can extract highfrequency detailed information in multiple scales and from diverse directions. The combination of the two methods is conducive to the acquisition of more characteristics and more accurate fusion results. Among them, for the low-frequency component, a new type of top-hat transform is used to extract low-frequency features, and then different fusion rules are applied to fuse the low-frequency features and low-frequency background; for high-frequency components, the product of characteristics method is used to integrate the detailed information in high-frequency. Experimental results show that the proposed algorithm can obtain more detailed information and clearer infrared target fusion results than the traditional multiscale transform methods. Compared with the state-of-the-art fusion methods based on sparse representation, the proposed algorithm is simple and efficacious, and the time consumption is significantly reduced.展开更多
Apocynum venetum/cotton blended fabrics have been subjected to treat with cationic polymer nanoparticles followed by dyeing with Acid Red B,and then studied for their dyeing performance and morphology.The investigatio...Apocynum venetum/cotton blended fabrics have been subjected to treat with cationic polymer nanoparticles followed by dyeing with Acid Red B,and then studied for their dyeing performance and morphology.The investigation on the effect of modification factors on the blended fabrics indicated that the 0.5 g/L nanoparticles concentration,60 min treating time,60 ℃ treating temperature and pH 6-8 are the optimum modification process to improve the dyeability of acid dye.In addition,the SEM images show that nanoparticles can be adsorbed on the surface of modified A.venetum or cotton fibers,and the two different fibers could have the same adsorption ability to Acid Red B.展开更多
By the modification, network carbide is disconnected at 1100 degree C through uneven dissolution at higher energy places in carbide, where there is twin or lattice distortion, and is granulated at 1130 degree C throug...By the modification, network carbide is disconnected at 1100 degree C through uneven dissolution at higher energy places in carbide, where there is twin or lattice distortion, and is granulated at 1130 degree C through element diffusion. The stability of M//7C//3 carbide is decreased because of the modification reducing the segregation of Cr and Mo, thus the temperature, at which uneven dissolution of carbide commenced, is decreased. Also lattice distortion or defect such as twin in carbide is increased by the modification, which prompts widespread disconnections in carbide. In addition, the modification prompts element diffusion to accelerate the kinetics process of carbide granulation. (Edited author abstract) 6 Refs.展开更多
Side-chain modification is a proven effective approach for morphology manipulation in organic solar cells(OSCs).However,in-depth analysis and investigation involving side-chain modification towards morphology improvem...Side-chain modification is a proven effective approach for morphology manipulation in organic solar cells(OSCs).However,in-depth analysis and investigation involving side-chain modification towards morphology improvement,including molecular microstructure,orientating packing and aggregation are urgent for all-small-molecule(ASM)systems.Herein,employing a fluorine-modified two-dimension benzodithiophene(BDT)as central unit,we contrastively synthesized two small-molecule donors,namely BDT-F-SR and BDT-F-R,each welding alkylthio side-chains on thienyl of central BDT unit and the other grafted non-sulfuric alkyl side-chains.As predicted,the synergetic side-chain modification of fluorination and alkyl changeover triggers diverse molecular dipole moments and orientations,resulting in different molecular energy levels,thermal stabilities,molecular planarity and order.Eventually,together with the preeminent small-molecule acceptor Y6,BDT-F-R-based ASM OSCs obtain enhanced power conversion efficiency(PCE)of 13.88%compared to BDT-F-SR-based devices(PCE of 12.75%)with more suitable phase-separation and balanced carrier mobilities.The contrast results reveal that alkyl sidechains seem to be a more satisfactory partner for fluorine-modified 2D BDT-based small-molecule donors compared to alkylthio pendants,and highlight the significance of subtle side-chain modification for molecular structural order fun-tuning and morphology control,laying the foundation for efficient ASM OSCs.展开更多
The austenite medium Mn steel modified with controlled additions of Ca, Y, Si were directionally solidified using the vertical Bridgman method to study the effects of Ca（Y）-Si modifier on the solid-liquid （S-L） in...The austenite medium Mn steel modified with controlled additions of Ca, Y, Si were directionally solidified using the vertical Bridgman method to study the effects of Ca（Y）-Si modifier on the solid-liquid （S-L） interface morphology and solute segregation. The interface morphology and the C and Mn segregation of the steel directionally solidified at 6.9 μtrn/s were investigated with an image analysis and a scanning electron microscope equipped with energy dispersive X-ray analysis. The 0.5wt% Ca-Si modified steel is solidified with a planar S-L interface. The interface of the 1.0wt% Ca-Si modified steel is similar to that of the 0.5wt% Ca-Si modified steel, but with larger nodes. The 1.5wt% Ca-Si modified steel displays a cellular growth parttern. The S-L interface morphology of the 0.5wt% Ca-Si＋1.0wt% Y-Si modified Mn steel appears as dendritic interface, and primary austenite dendrites reveal developed lateral branching at the quenched liquid. In the meantime, the independent austenite colonies are formed ahead of the S-L interface. A mechanism involving constitutional supercooling explains the S-L interface evolution. It depends mainly on the difference in the contents of Ca, Y, and Si ahead of the S-L interface. The segregation of C and Mn ahead of the S-L interface enhanced by the modifiers is observed.展开更多
In view of the special requirements of transducers for power ultrasonic processing,the piezoelectric ceramic material Pb(Zr,Ti)O3 was modified by adding other effective elements.The piezoelectric ceramic piece has a g...In view of the special requirements of transducers for power ultrasonic processing,the piezoelectric ceramic material Pb(Zr,Ti)O3 was modified by adding other effective elements.The piezoelectric ceramic piece has a good crystal phase structure,a stable piezoelectric constant,a higher dielectric constant,and a lower dielectric loss by adding a small amount of Sr^2+,Ba^2+,Ga^2+,Sn^4+,Nb^5+,etc.These properties are well suited to requirements of power ultrasonic transducer more than 1 000 W.The crystal phase structure and surface morphology of the modified piezoelectric ceramic chips were analyzed by X-ray and scanning electron microscopy (SEM) to prove that the piezoelectric ceramic chips have good crystal structure and density.The dielectric constant of the polarized piezoelectric ceramic chips was measured using an LCR meter.Finally,the piezoelectric ceramic chips were used to design the ultrasonic transducer,and the transducer was analyzed and measured by the impedance analyzer.The measurement results show that the performance of the piezoelectric ceramic chips is reasonable and feasible.展开更多
Biopolymer fibers have great potential for technical applications in biomaterials.The surface properties of fibers are of importance in these applications.In this study,electrospun poly(L-lactide)(PLLA)/poly(ε-caprol...Biopolymer fibers have great potential for technical applications in biomaterials.The surface properties of fibers are of importance in these applications.In this study,electrospun poly(L-lactide)(PLLA)/poly(ε-caprolactone)(PCL)membranes were modified by cold plasma treatment and coating gelatin to improve the surface hydrophilic properties.The morphologies of the fibers were observed by scanning electron microscopy(SEM).Atomic force microscopy(AFM)was employed to show the surface characteristics of the fibers.The chemical feature of the fibrous membrane surfaces was examined by X-ray photoelectron spectroscopy(XPS).The surface wettability of the fibrous membrane was also characterized by water contact angle measurements.All these results show that plasma treatment can have profound effects on the surface properties of fibrous membranes by changing their surface physical and chemical features.Gelatin-PLLA/PCL membrane has great potential in applications of tissue engineering scaffolds.展开更多
In this paper functionalized multiwall carbon nanotubes (FMWCNT) were modified using atenolol as a class of drugs that were used in cardiovascular diseases containing reactable nitrogen, which could attach chemically ...In this paper functionalized multiwall carbon nanotubes (FMWCNT) were modified using atenolol as a class of drugs that were used in cardiovascular diseases containing reactable nitrogen, which could attach chemically to functionalized MWCNT. This product was characterized by Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. These spectrums proved the existence of nitrogen atoms of amide due to new functional group. The morphology were also determined by scanning electron microscopy (SEM) and showed that this product was synthesized in the nanometer dimension. Thermal gravimetery (TGA) analysis was also used to evaluate thermal properties.展开更多
基金National Natural Science Foundation of China(No.61261029)
文摘Watershed segmentation is sensitive to noises and irregular details within the image,which frequently leads to a serious over-segmentation Linear filtering before watershed segmentation can reduce over-segmentation to some extent,however,it often causes the position offset of object contours.For the purpose of reducing over-segmentation to preserve the location of object contours,the watershed segmentation based on the hierarchical multi-scale modification of morphological gradient is proposed.Firstly,multi-scale morphological filtering was employed to smooth the original image.Then,the gradient image was divided into multi-levels by the volume of three-dimension topographic relief,where the lower gradient layers were further modifiedby morphological closing with larger-sized structuring-elements,and the higher layers with the smaller one.In this way,most local minimums caused by irregular details and noises can be removed,while region contour positions corresponding to the target area were largely preserved.Finally,morphological watershed algorithm was employed to implement segmentation on the modified gradient image.The experimental results show that the proposed method can greatly reduce the over-segmentation of the watershed and avoid the position offset of the object contours.
基金supported by the National Natural Science Foundation of China(Nos.62475121 and 62335012)。
文摘A scheme based on irregular V-shaped silicon nanoantennas is proposed to optimize transverse unidirectional scattering under plane wave irradiation.Traditional methods of designing regular shapes offer fewer parameters and higher search efficiency.However,due to the limitations of regular shapes,it is challenging to meet high-precision design requirements.Irregular shape design allows for a broader range of adjustments,but the complexity of shape parameters leads to lower search efficiency and a higher likelihood of converging to local optima.
基金Supported the NatioIlal Naturel Science Foundation of China(No.69831040)
文摘This paper introduces a multi-scale morphological edge detection algorithm to extract SAR image edge which suffers seriously from noise. Combining the basic theme of morphology with that of multi-scale analysis, the algorithm presents the outstanding characteristics of accuracy and robustness. Comparative Experiments reveal its fine performance.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11804384,51802343,and 51772326)the Fundamental Research Funds for the Central Universities,China(Grant No.3122018L006)+2 种基金the Scientific Research Project of Tianjin Education Commission(Grant No.2019ZD19)the National Natural Science Foundation of China and the Civil Aviation Administration of China(Grant No.U1933109)Open Project of State Key Laboratory of Superhard Materials(Jilin University)(Grant No.201803).
文摘We observed morphological modification of rod-shaped C60 solvate crystals using a facile hydrothermal method.The initial C60 rods were changed from smooth rods to rough rods,porous rods or pieces under different hydrothermal conditions.During the hydrothermal treatment,the initial samples underwent a decomposition-recrystallization process,which can be tuned by the content of alcohol in the hydrothermal solution,thereby leading to modification of the morphological properties of the initial C60 rods.In addition,the rough and porous C60 rods prepared in our work exhibit excellent photoluminescence intensities that are approximately 7 and 3 times higher than those of pure C60 powders,respectively.Our results suggest that the hydrothermal method is a potential route for fabricating fullerene materials with controllable morphologies and novel functions.
基金supported by National Natural Science Foundation of China (No. 61763037)Inner Mongolia Autonomous Region Natural Science Foundation of China(No. 2019LH06007)Science and Technology Plan Project of Inner Mongolia (No. 2019,2020GG028)。
文摘Working conditions of rolling bearings of wind turbine generators are complicated, and their vibration signals often show non-linear and non-stationary characteristics. In order to improve the efficiency of feature extraction of wind turbine rolling bearings and to strengthen the feature information, a new structural element and an adaptive algorithm based on the peak energy are proposed,which are combined with spectral correlation analysis to form a fault diagnosis algorithm for wind turbine rolling bearings. The proposed method firstly addresses the problem of impulsive signal omissions that are prone to occur in the process of fault feature extraction of traditional structural elements and proposes a "W" structural element to capture more characteristic information. Then, the proposed method selects the scale of multi-scale mathematical morphology, aiming at the problem of multi-scale mathematical morphology scale selection and structural element expansion law. An adaptive algorithm based on peak energy is proposed to carry out morphological scale selection and structural element expansion by improving the computing efficiency and enhancing the feature extraction effect.Finally, the proposed method performs spectral correlation analysis in the frequency domain for an unknown signal of the extracted feature and identifies the fault based on the correlation coefficient. The method is verified by numerical examples using experimental rig bearing data and actual wind field acquisition data and compared with traditional triangular and flat structural elements. The experimental results show that the new structural elements can more effectively extract the pulses in the signal and reduce noise interference,and the fault-diagnosis algorithm can accurately identify the fault category and improve the reliability of the results.
基金Funded by the Open Foundation of National Key Laboratory of Green Building Materials(CBM-08-KF103)
文摘The features of alkali activated slag（AAS） and portland cement （PC） were observed on multi-scale,the crack and fracture sections were observed with naked eyes,and SEM and AFM were used to study the structure morphology differences between PC and AAS on micrometer to nano meter scale.The experimental results indicated that the AAS paste had soil like fracture texture and it was composed of mainly C-S-H gel but lacks of crystals,and it had a very strong tendency to shrink and crack.AAS paste is much denser and more homogeneous than PC,and on the nano scale C-S-H nano particle in the AAS paste is much smaller and packs much denser than PC paste.
文摘Seismic energy decays while propagating subsurface, which may reduce the resolution of seismic data. This paper studies the method of seismic energy dispersion compensation which provides the basic principles for multi-scale morphology and the spectrum simulation method. These methods are applied in seismic energy compensation. First of all, the seismic data is decomposed into multiple scales and the effective frequency bandwidth is selectively broadened for some scales by using a spectrum simulation method. In this process, according to the amplitude spectrum of each scale, the best simulation range is selected to simulate the middle and low frequency components to ensure the authenticity of the simulation curve which is calculated by the median method, and the high frequency component is broadened. Finally, these scales are reconstructed with reasonable coefficients, and the compensated seismic data can be obtained. Examples are shown to illustrate the feasibility of the energy compensation method.
文摘Being used more and more widely in engineering,AlSi alloys comprise about 80%of all kinds of aluminum alloys,which are the most widely utilized nonferrous alloys.Although most Al-Si alloys consist of multiple components,the eutectics in the structure accounts for 50%-90%of the sum volume of such alloys.Therefore,understanding the modification mechanism and function rules of the AlSi eutectic solidification is the technical key in controlling the structures and properties of such casting alloys.The present paper chiefly reviews recent investigation developments and important conclusions along the lines of the functions of modification elements and their modification mechanism in the eutectic solidification of Al-Si alloys.
基金Project(2013B090500091)supported by Industry-University-Research Combined Project of Guangdong Province,ChinaProject(20180358)supported by the Shenzhen Jiansheng Technology Inc.Cooperation Project,China。
文摘Trace amount of Sr(0.05 wt.%)was added into the hypoeutectic Al−Si(3−12 wt.%Si)alloys to modify their microstructure and improve thermal conductivity.The results showed that the thermal conductivity of hypoeutectic Al−Si alloys was improved by Sr modification,and the increment and increasing rate of the thermal conductivity gradually increased with Si content increasing.The improvement of thermal conductivity was primarily related to the morphology variation of eutectic Si phases.In Sr-modified Al−Si alloys,the morphology of eutectic Si phases was a mixed morphology of fiber structure and fine flaky structure,and the proportion of the fine flaky eutectic Si phases gradually decreased with Si content increasing.Under the Si content reaching 9 wt.%,the proportion of fine flaky eutectic Si phases was nearly negligible in Sr-modified alloys.Correspondingly,the increment and increasing rate of thermal conductivity of Sr-modified alloys reached the maximum and tended to be stable.
文摘The effects of calcination and modification on the morphology （shapes and textures） and crystal structure of anhydrite powders were studied. The results show that, calcination at 100℃ causes anhydrite to disintegrate into smaller crystals, accompanied by a slight in- crease in d-spacing. Without calcination and modification, the solidification time and curing time of anhydrite are 15 and 77 h, respectively. After the treatment, however, the solidification time and curing time are shortened significantly to 9.5 and 14 rain, respectively. The com- pressive and flexural strengths of hydration products made from the treated anhydrite reach 10.2 and 2.0 MPa, respectively. The much shorter solidification and curing time make it possible to use anhydrite as a building and construction material.
基金This work was supported by The National Science Foundation(Cranted Number 29874030)
文摘The morphological and compositional changes of the PP fibers pretreated with dielectric barrier discharge (DBD)are investigated with SEM, XPS and IR. The result shows that the etching effect is the main reason for the improvement of the result of pull-out test of the fibercement composite reported in a previous paper and the oxidation of the fiber surface also favors the adhesion between the fiber and the matrix.
文摘In the present study, the structural modification of sand cast Al-12wt%Si alloy with sulfur/sodium and its effect on mechanical properties were investigated. Different addition levels of sulfur and sodium were used to modify and produce castings of the same shape and size from the alloy. The results indicated that the addition of sodium or sulfur to eutectic Al-Si alloy can modify the Al-Si eutectic morphology from needle-like eutectic silicon structure to fine-scale eutectic silicon structure with significant improvement in mechanical properties of the alloy. The optimum levels of modification by sodium flux (60% NaF and 40% NaCl) and sulfur were found to be 0.6% - 1.0% and 0.02% - 0.05% of the weight of the alloy respectively. The alloy modified with 0.6% Na flux had the best mechanical properties closely followed by the one modified with 0.02% sulfur. Over modification of the alloy with sodium produced over modification band which consisted of aluminum dendrites and coarse silicon particles in the microstructure of the alloy. Increase in concentration of sulfur decreased the degree of fineness of the eutectic silicon structure with significant decrease in mechanical properties of the alloy and this is suggested to be as a result of the presence of a brittle sulfur compound at the grain interfaces of the alloy.
基金Project supported by the National Natural Science Foundation of China(Grant No.61402368)Aerospace Support Fund,China(Grant No.2017-HT-XGD)Aerospace Science and Technology Innovation Foundation,China(Grant No.2017 ZD 53047)
文摘The high-frequency components in the traditional multi-scale transform method are approximately sparse, which can represent different information of the details. But in the low-frequency component, the coefficients around the zero value are very few, so we cannot sparsely represent low-frequency image information. The low-frequency component contains the main energy of the image and depicts the profile of the image. Direct fusion of the low-frequency component will not be conducive to obtain highly accurate fusion result. Therefore, this paper presents an infrared and visible image fusion method combining the multi-scale and top-hat transforms. On one hand, the new top-hat-transform can effectively extract the salient features of the low-frequency component. On the other hand, the multi-scale transform can extract highfrequency detailed information in multiple scales and from diverse directions. The combination of the two methods is conducive to the acquisition of more characteristics and more accurate fusion results. Among them, for the low-frequency component, a new type of top-hat transform is used to extract low-frequency features, and then different fusion rules are applied to fuse the low-frequency features and low-frequency background; for high-frequency components, the product of characteristics method is used to integrate the detailed information in high-frequency. Experimental results show that the proposed algorithm can obtain more detailed information and clearer infrared target fusion results than the traditional multiscale transform methods. Compared with the state-of-the-art fusion methods based on sparse representation, the proposed algorithm is simple and efficacious, and the time consumption is significantly reduced.
基金supported by National Natural Science Foundation of China(No.51173086)National Key Technology R&D Program,(Nos.2014BAC13B02 and 2014BAE01B01)+1 种基金Industrialization Projects of Major Independent Innovation Achievements of Shandong Province(No.2012ZHZX1A0914)Application Basis and Cutting-edge Technology Research Project of Tianjin(No.14JCZDJC37200)
文摘Apocynum venetum/cotton blended fabrics have been subjected to treat with cationic polymer nanoparticles followed by dyeing with Acid Red B,and then studied for their dyeing performance and morphology.The investigation on the effect of modification factors on the blended fabrics indicated that the 0.5 g/L nanoparticles concentration,60 min treating time,60 ℃ treating temperature and pH 6-8 are the optimum modification process to improve the dyeability of acid dye.In addition,the SEM images show that nanoparticles can be adsorbed on the surface of modified A.venetum or cotton fibers,and the two different fibers could have the same adsorption ability to Acid Red B.
文摘By the modification, network carbide is disconnected at 1100 degree C through uneven dissolution at higher energy places in carbide, where there is twin or lattice distortion, and is granulated at 1130 degree C through element diffusion. The stability of M//7C//3 carbide is decreased because of the modification reducing the segregation of Cr and Mo, thus the temperature, at which uneven dissolution of carbide commenced, is decreased. Also lattice distortion or defect such as twin in carbide is increased by the modification, which prompts widespread disconnections in carbide. In addition, the modification prompts element diffusion to accelerate the kinetics process of carbide granulation. (Edited author abstract) 6 Refs.
基金the Natural Science Foundation of Chongqing(cstc2019jcyj-msxmX0400)Youth Innovation Promotion Association Chinese Academy of Sciences(2020379)+2 种基金Chongqing Funds for Distinguished Young Scientists(cstc2020jcyj-jqX0018)General Program of National Natural Science Foundation of China(62074149)National Natural Science Foundation of China(51961165102).
文摘Side-chain modification is a proven effective approach for morphology manipulation in organic solar cells(OSCs).However,in-depth analysis and investigation involving side-chain modification towards morphology improvement,including molecular microstructure,orientating packing and aggregation are urgent for all-small-molecule(ASM)systems.Herein,employing a fluorine-modified two-dimension benzodithiophene(BDT)as central unit,we contrastively synthesized two small-molecule donors,namely BDT-F-SR and BDT-F-R,each welding alkylthio side-chains on thienyl of central BDT unit and the other grafted non-sulfuric alkyl side-chains.As predicted,the synergetic side-chain modification of fluorination and alkyl changeover triggers diverse molecular dipole moments and orientations,resulting in different molecular energy levels,thermal stabilities,molecular planarity and order.Eventually,together with the preeminent small-molecule acceptor Y6,BDT-F-R-based ASM OSCs obtain enhanced power conversion efficiency(PCE)of 13.88%compared to BDT-F-SR-based devices(PCE of 12.75%)with more suitable phase-separation and balanced carrier mobilities.The contrast results reveal that alkyl sidechains seem to be a more satisfactory partner for fluorine-modified 2D BDT-based small-molecule donors compared to alkylthio pendants,and highlight the significance of subtle side-chain modification for molecular structural order fun-tuning and morphology control,laying the foundation for efficient ASM OSCs.
基金This work is financially supported by the National Natural Science Foundation of China (No.50001008 and No. 50271042).
文摘The austenite medium Mn steel modified with controlled additions of Ca, Y, Si were directionally solidified using the vertical Bridgman method to study the effects of Ca（Y）-Si modifier on the solid-liquid （S-L） interface morphology and solute segregation. The interface morphology and the C and Mn segregation of the steel directionally solidified at 6.9 μtrn/s were investigated with an image analysis and a scanning electron microscope equipped with energy dispersive X-ray analysis. The 0.5wt% Ca-Si modified steel is solidified with a planar S-L interface. The interface of the 1.0wt% Ca-Si modified steel is similar to that of the 0.5wt% Ca-Si modified steel, but with larger nodes. The 1.5wt% Ca-Si modified steel displays a cellular growth parttern. The S-L interface morphology of the 0.5wt% Ca-Si＋1.0wt% Y-Si modified Mn steel appears as dendritic interface, and primary austenite dendrites reveal developed lateral branching at the quenched liquid. In the meantime, the independent austenite colonies are formed ahead of the S-L interface. A mechanism involving constitutional supercooling explains the S-L interface evolution. It depends mainly on the difference in the contents of Ca, Y, and Si ahead of the S-L interface. The segregation of C and Mn ahead of the S-L interface enhanced by the modifiers is observed.
基金Funded by the National Natural Science Foundation of China(51975540)the Youth Science and Technology Research Fundation of Shanxi Province of China(201901D211204)。
文摘In view of the special requirements of transducers for power ultrasonic processing,the piezoelectric ceramic material Pb(Zr,Ti)O3 was modified by adding other effective elements.The piezoelectric ceramic piece has a good crystal phase structure,a stable piezoelectric constant,a higher dielectric constant,and a lower dielectric loss by adding a small amount of Sr^2+,Ba^2+,Ga^2+,Sn^4+,Nb^5+,etc.These properties are well suited to requirements of power ultrasonic transducer more than 1 000 W.The crystal phase structure and surface morphology of the modified piezoelectric ceramic chips were analyzed by X-ray and scanning electron microscopy (SEM) to prove that the piezoelectric ceramic chips have good crystal structure and density.The dielectric constant of the polarized piezoelectric ceramic chips was measured using an LCR meter.Finally,the piezoelectric ceramic chips were used to design the ultrasonic transducer,and the transducer was analyzed and measured by the impedance analyzer.The measurement results show that the performance of the piezoelectric ceramic chips is reasonable and feasible.
基金National Demonstration Center for Experimental Materials Science and Engineering Education(Donghua University),China。
文摘Biopolymer fibers have great potential for technical applications in biomaterials.The surface properties of fibers are of importance in these applications.In this study,electrospun poly(L-lactide)(PLLA)/poly(ε-caprolactone)(PCL)membranes were modified by cold plasma treatment and coating gelatin to improve the surface hydrophilic properties.The morphologies of the fibers were observed by scanning electron microscopy(SEM).Atomic force microscopy(AFM)was employed to show the surface characteristics of the fibers.The chemical feature of the fibrous membrane surfaces was examined by X-ray photoelectron spectroscopy(XPS).The surface wettability of the fibrous membrane was also characterized by water contact angle measurements.All these results show that plasma treatment can have profound effects on the surface properties of fibrous membranes by changing their surface physical and chemical features.Gelatin-PLLA/PCL membrane has great potential in applications of tissue engineering scaffolds.
文摘In this paper functionalized multiwall carbon nanotubes (FMWCNT) were modified using atenolol as a class of drugs that were used in cardiovascular diseases containing reactable nitrogen, which could attach chemically to functionalized MWCNT. This product was characterized by Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. These spectrums proved the existence of nitrogen atoms of amide due to new functional group. The morphology were also determined by scanning electron microscopy (SEM) and showed that this product was synthesized in the nanometer dimension. Thermal gravimetery (TGA) analysis was also used to evaluate thermal properties.
