This paper illuminates the preparation of grating-like polystyrene latex monolayer structure, which can minimize the effects of the size deviation of spheres and the defect transfer on the accuracy as calibration samp...This paper illuminates the preparation of grating-like polystyrene latex monolayer structure, which can minimize the effects of the size deviation of spheres and the defect transfer on the accuracy as calibration samples for micro-scopes. The latex films are grown on freshly cleaved mica substrates by vertical deposition method. The concentration dependence of the structure and the topography of latex films is characterized by optical microscope, ultraviolet- visible transmission spectrum and scanning probe microscope. The origination of such a grating-like structure is also discussed.展开更多
Scanning Probe Microscopes (SPMs) observe specimen surfaces with probes by detecting the physical amount of a material between the cantilever and the surface. SPMs have a high resolution and can measure mechanical cha...Scanning Probe Microscopes (SPMs) observe specimen surfaces with probes by detecting the physical amount of a material between the cantilever and the surface. SPMs have a high resolution and can measure mechanical characteristics such as stiffness, adsorptive properties, and viscoelasticity. These features make it easy to identify the surface structure of complex materials;therefore, the use of SPMs has increased in recent years. Wood cell walls are primarily composed of cellulose, hemicellulose, and lignin. It is believed that hemicellulose and lignin surround the cellulose framework;however, their detailed formation remains unknown. Therefore, we observed wood cell walls via scanning probe microscopy to try to reveal the formation of the cellulose framework. We determined that the size of the cellulose microfibril bundle and hemicellulose lignin module composite was 18.48 nm based on topography and that the size of the cellulose microfibril bundle was 15.33 nm based on phase images. In the viscoelasticity image, we found that the viscoelasticities of each cell wall of the same cell were not the same. This is because the cellulose microfibrils in each cell wall lean in different directions. The angle between the leaning of the cellulose microfibril and the cantilever affects the viscoelasticity measurement.展开更多
An experimental study on cutting amorphous alloy at nanometer scale is conducted by applying the principle and technology of scanning probe microscope(SPM) It is revealed from the experiments that cutting inside SPM...An experimental study on cutting amorphous alloy at nanometer scale is conducted by applying the principle and technology of scanning probe microscope(SPM) It is revealed from the experiments that cutting inside SPM is an excellent and direct way to research the material removal process at small size Based on the experimental results,the chip formation mechanism for the cutting of amorphous alloy is discussed It is found that the deformation along the direction of chip flow occurs ahead of the appearance of localized shear,and a simplified geometrical model is proposed to illustrate the deformation.展开更多
The surface of a compact disk is analyzed by using SPM and the quantitative micromorphology analysissoftware SPMIAS developed by the author. Images at the same position but with different scanning ranges areobtained ...The surface of a compact disk is analyzed by using SPM and the quantitative micromorphology analysissoftware SPMIAS developed by the author. Images at the same position but with different scanning ranges areobtained under the same experimental conditions. Micromorphology parameters are calculated and compared, andthe relationship between the changing of the scanning range and the changing of micromorphology parameters issummarized.展开更多
The localized micro-galvanic corrosion process and the kinetic information of Mg-(7,9)Al-1Fe-x Nd alloys were investigated by in situ observation under electrochemical control and in situ atomic force microscopy(AFM)i...The localized micro-galvanic corrosion process and the kinetic information of Mg-(7,9)Al-1Fe-x Nd alloys were investigated by in situ observation under electrochemical control and in situ atomic force microscopy(AFM)in an electrolyte environment.The results revealed that the formation of the Nd-rich phase in alloys resulted in a decrease in the Volta potential difference from~400 m V(AlFe3/α-Mg)to~220 mV(Nd-rich/α-Mg),reducing the corrosion products around the cathodic phase and corrosion current density of the microscale area.The addition of Nd significantly improved the corrosion resistance,mainly due to the suppression of the micro-galvanic corrosion between the second phases and substrate.Finally,the corrosion mechanism of Mg-(7,9)Al-1Fe-x Nd alloys was discussed based on in situ observations and electrochemical results.展开更多
基金supported by Science and Technology Commission of Shanghai Municipality (Grant No 0652NM028)Shanghai Leading Academic Discipline Project of China (B113)the International Research Training Group (IRTG)
文摘This paper illuminates the preparation of grating-like polystyrene latex monolayer structure, which can minimize the effects of the size deviation of spheres and the defect transfer on the accuracy as calibration samples for micro-scopes. The latex films are grown on freshly cleaved mica substrates by vertical deposition method. The concentration dependence of the structure and the topography of latex films is characterized by optical microscope, ultraviolet- visible transmission spectrum and scanning probe microscope. The origination of such a grating-like structure is also discussed.
文摘Scanning Probe Microscopes (SPMs) observe specimen surfaces with probes by detecting the physical amount of a material between the cantilever and the surface. SPMs have a high resolution and can measure mechanical characteristics such as stiffness, adsorptive properties, and viscoelasticity. These features make it easy to identify the surface structure of complex materials;therefore, the use of SPMs has increased in recent years. Wood cell walls are primarily composed of cellulose, hemicellulose, and lignin. It is believed that hemicellulose and lignin surround the cellulose framework;however, their detailed formation remains unknown. Therefore, we observed wood cell walls via scanning probe microscopy to try to reveal the formation of the cellulose framework. We determined that the size of the cellulose microfibril bundle and hemicellulose lignin module composite was 18.48 nm based on topography and that the size of the cellulose microfibril bundle was 15.33 nm based on phase images. In the viscoelasticity image, we found that the viscoelasticities of each cell wall of the same cell were not the same. This is because the cellulose microfibrils in each cell wall lean in different directions. The angle between the leaning of the cellulose microfibril and the cantilever affects the viscoelasticity measurement.
基金This project is supported by Foundation of National Education Ministry for Returned Overseas Chinese Scholars(No.2000367) an
文摘An experimental study on cutting amorphous alloy at nanometer scale is conducted by applying the principle and technology of scanning probe microscope(SPM) It is revealed from the experiments that cutting inside SPM is an excellent and direct way to research the material removal process at small size Based on the experimental results,the chip formation mechanism for the cutting of amorphous alloy is discussed It is found that the deformation along the direction of chip flow occurs ahead of the appearance of localized shear,and a simplified geometrical model is proposed to illustrate the deformation.
文摘The surface of a compact disk is analyzed by using SPM and the quantitative micromorphology analysissoftware SPMIAS developed by the author. Images at the same position but with different scanning ranges areobtained under the same experimental conditions. Micromorphology parameters are calculated and compared, andthe relationship between the changing of the scanning range and the changing of micromorphology parameters issummarized.
基金financial support from the National Natural Science Foundation of China(No.51961026)。
文摘The localized micro-galvanic corrosion process and the kinetic information of Mg-(7,9)Al-1Fe-x Nd alloys were investigated by in situ observation under electrochemical control and in situ atomic force microscopy(AFM)in an electrolyte environment.The results revealed that the formation of the Nd-rich phase in alloys resulted in a decrease in the Volta potential difference from~400 m V(AlFe3/α-Mg)to~220 mV(Nd-rich/α-Mg),reducing the corrosion products around the cathodic phase and corrosion current density of the microscale area.The addition of Nd significantly improved the corrosion resistance,mainly due to the suppression of the micro-galvanic corrosion between the second phases and substrate.Finally,the corrosion mechanism of Mg-(7,9)Al-1Fe-x Nd alloys was discussed based on in situ observations and electrochemical results.
