389 resultados para AL2O3 POWDERS


Relevância:

20.00% 20.00%

Publicador:

Resumo:

It is reported for the first time that horseradish peroxidase (HRP) immobilized on the active carbon can undergo a direct quasi-reversible electrochemical reaction. In addition, the immobilized HRP showed the stable bioelectrocatalytic activity for the reduction of H2O2.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

一种CuO/Al#-[2]O#-[3]脱硫剂的再生方法是将吸硫的CuO/γ-Al#-[2]O#-[3]脱硫剂在含氨气气氛中还原再生,再生温度为350-500℃,空速为500-3000h#+[-1],再生时间为30-90分钟。本发明的再生过程简单,易操作,二次脱硫活性稳定,可实现脱硫温度下的有效还原再生;再生过程中生成的SO#-[2]在低温条件下可与未反应的NH#-[3]结合生成固体硫酸铵盐,不仅简化了再生后续处理工序,而且可增强本再生方法的经济效益,降低了脱硫综合成本。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ti45--xZr35--xNi17+2rCU3 (x=0, 2, 4, 6 and 8) icosahedral quasicrystalline phase (I-phase) alloy powders are synthesized by mechanical alloying and subsequent annealing techniques, and the crystallographic and electrochemical characteristics are investigated. The alloy powders are I-phase, and the quasi-lattice constant decreases with increasing x value. The maximum discharge capacity of the I-phase alloy electrodes first increases and then decreases with increasing x value, and the Ti39Zr26Ni29Cu3 I-phase electrode exhibits the highest discharge capacity of 274 mAh g(--1). The high-rate dischargeability at the discharge current density of 240mA g(--1) increases from 55.31 % (x= 0) to 74.24% (x= 8). Cycling stability also increases with increasing x value. The improvement in electrochemical characteristics may be ascribed to the added nickel, which not only improves the electrochemical activity, but also makes the alloy more resistant to oxidation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ti45Zr35Ni17Cu3 amorphous and single icosahedral quasicrystalline powders were synthesized by mechanical alloying and subsequent annealing at 855 K. Microstructure and electrochemical properties of two alloy electrodes were characterized. When the temperature was enhanced from 303 to 343 K, the maximum discharge capacities increased from 86 to 329 mAh g(-1) and 76 to 312 mAh g(-1) for the amorphous and quasicrystalline alloy electrodes, respectively. Discharge capacities of two electrodes decrease distinctly with increasing cycle number. The I-phase is stable during charge/discharge cycles, and the main factors for its discharge capacity loss are the increase of the charge-transfer resistance and the pulverization of alloy particles. Besides the factors mentioned above, the formation of TiH2 and ZrH2 hydrides is another primary reason for the discharge capacity loss of the amorphous alloy electrode.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A facile molten salt synthesis route was developed to prepare ZnTiO3 ceramic powders with simple oxides ZnO and TiO2 using sodium and potassium chloride eutectic salts as flux. The role of calcination temperature and time and the amount of salt addition to ZnTiO3 formation was investigated by thermogravimetry-differential thermal analysis, X-ray diffraction and Fourier transformation-infrared spectroscopy measurements. Pure hexagonal phase of ZnTiO3 could be obtained from the mixture of the simple oxides and the chlorides (50 mol% KCl, 20 times to oxides in molar ratio) heating at 800 degrees C for 6 h. The scanning electron microscopy images revealed the products were hexagonal sheets of about 1-3 mu m size. Increasing the amount of salt aids in reducing the crystal sizes of final ceramic powders because of diluting the solution.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The system Al2O3-B2O3 containing Ce3+ and Tb3+ ions was investigated for the first time. It was found that certain compositions give rise to a new highly efficient green luminescent material.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

中国科学院山西煤炭化学研究所

Relevância:

20.00% 20.00%

Publicador:

Resumo:

中国科学院山西煤炭化学研究所

Relevância:

20.00% 20.00%

Publicador:

Resumo:

中国科学院山西煤炭化学研究所

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A composite polymer electrolyte of Polyethylene oxide (PEO)-LiClO4 containing fine Al2O3 particles was studied by using differential scanning calorimetry, infrared spectroscopy and electrochemical impedance spectroscopy. Compared with the polymer electrolyte without Al2O3 particles, the glass transition temperature and the degree of crystallinity were decreased, and the room temperature conductivity of PEO-LiClO4-Al2O3 composite polymer electrolyte was considerably enhanced. Moreover, the equivalent circuits and the effect of dc potential on impedance spectroscopy were discussed.