scholarly journals Synthesis ofMnO2Microfiber with Secondary Nanostructure by Cotton Template

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Huan-qin Wang ◽  
Ming-bo Zheng ◽  
Jin-hua Chen ◽  
Guang-bin Ji ◽  
Jie-ming Cao

HierarchicalMnO2microfibers were prepared by using cotton as the template andKMnO4as the precursor via an ultrasonic assistance route. The results of scanning electron microscope characterization showed that the concentration ofKMnO4had a significant effect on the morphology ofMnO2microfiber. At low concentration ofKMnO4, the microfiber was composed ofMnO2nanorods with single crystal structure. With increasing the concentration ofKMnO4, the secondary nanostructure ofMnO2microfibers had a transformation from nanorod to nanoparticle. The results ofN2adsorption-desorption analysis indicated thatMnO2microfibers had BET surface area of about 25 m2/g. This synthesis provides a new way to control the secondary nanostructure ofMnO2microfiber by adjusting the concentration of precursor. Furthermore, the mechanism for the replication was proposed and discussed.

Author(s):  
R. B. Neder ◽  
M. Burghammer ◽  
Th. Grasl ◽  
H. Schulz

AbstractWe developed a new micro manipulator for mounting individual sub-micrometer sized single crystals within a scanning electron microscope. The translations are realized via a commercially available piezomicroscope, adapted for high vacuum usage and realize nanometer resolution. With this novel instrument it is routinely possible to mount individual single crystals with sizes down to 0.1


2011 ◽  
Vol 284-286 ◽  
pp. 1584-1587
Author(s):  
Zhen Xue Shi ◽  
Jia Rong Li ◽  
Shi Zhong Liu ◽  
Jin Qian Zhao

The specimens of low angle boundaries were machined from the second generation single crystal superalloy DD6 blades. The microstructures of low angle boundaries (LAB) were investigated from three scales of dendrite, γ′ phase and atom with optical microscopy (OM), scanning electron microscope (SEM), transition electron microscope (TEM) and high resolution transmission electrion microscopy (HREM). The results showed that on the dendrite scale LAB is interdendrite district formed by three dimensional curved face between the adjacent dendrites. On the γ′ phase scale LAB is composed by a thin layer γ phase and its bilateral imperfect cube γ′ phase. On the atom scale LAB is made up of dislocations within several atom thickness.


2007 ◽  
Vol 26-28 ◽  
pp. 243-246
Author(s):  
Xing Hua Yang ◽  
Jin Liang Huang ◽  
Xiao Wang ◽  
Chun Wei Cui

BaBi4-xLaxTi4O15 (BBLT) ceramics were prepared by conventional solid phase sintering ceramics processing technology. The crystal structure and the microstructure were detected by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD analyses show that La3+ ions doping did not change the crystal structure of BBT ceramics. The sintering temperature increased from 1120°C to 1150°C with increasing Lanthanum content from 0 to 0.5, but it widened the sintering temperature range from 20°C to 50°C and refined the grain size of the BBT ceramic. Additionally, polarization treatment was performed and finally piezoelectric property was measured. As a result, the piezoelectric constant d33 of the 0.1at.% doped BBLT ceramics reached its highest value about 22pc/N at polarizing electric field of 8kV/mm and polarizing temperature of 120°C for 30min.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Guang-zhe Deng ◽  
Rui Zheng

With the raw coal from a typical low-permeability coal seam in the coalfield of South Junger Basin in Xinjiang as the research object, this paper examined six kinds of coal samples with different permeabilities using a scanning electron microscope and a low-temperature nitrogen adsorption test that employed a JSM-6460LV high-resolution scanning electron microscope and an ASAP2020 automatic specific surface area micropore analyzer to measure all characteristic micropore structural parameters. According to fractal geometry theory, four fractal dimension calculation models of coal and rock were established, after which the pore structure characteristic parameters were used to calculate the fractal dimensions of the different coal seams. The results show that (1) the low-permeability coal seam in the coalfield of South Junger Basin in Xinjiang belongs to mesoporous medium, with a certain number of large pores and no micropores. The varying adsorption capacities of the different coal seams were positively correlated with pore volume, surface area, and the mesoporous surface area proportions, from which it was concluded that mesopores were the main contributors to pore adsorption in low-permeability coal seams. (2) The raw coal pore fractal dimension had a negative linear relationship to average pore size, a positive linear relationship with total pore volume, total surface area, and adsorption capacity, and a positive correlation with the mesoporous surface area proportion; that is, the higher the fractal dimension, the larger the pore volume and surface area of the raw coal. (3) The permeability of the low-permeability coal seam had a phase correlation with the micropore development degree; that is, the permeability had a phase negative correlation with the pore distribution fractal dimension, and there was a positive correlation between permeability and porosity. These results are of theoretical significance for the clean exploitation of low-permeability coal seam resources.


2013 ◽  
Vol 860-863 ◽  
pp. 956-959
Author(s):  
Xing Hua Liang ◽  
Lin Shi ◽  
Yu Si Liu ◽  
Tian Jiao Liu ◽  
Chao Chao Ye ◽  
...  

The High Potential Material Lini0.5Mn1.5O4 was Synthesized via Solid-State Reaction.The Surface Morphology and Particle Size of the Sample were Observed by Scanning Electron Microscope(SEM).The Crystal Structure of the Sample was Collected and Analyzed through X-Ray Diffractometry(XRD).The Sample was Charaterized by Charge-Discharge Tests.Results Indicated that the Cycling Retention Rate was about 80%,after being Charge-Diacharged at a Rate of 0.1C in a Voltage of 3.45-4.77V for 10 Times.Compared with Limn2O4,LiNi0.5Mn1.5O4 has good cycle performance.Both of LiNi0.5Mn1.5O4 structure were space group of Fd3m.


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