Magnesium hydroxide nanorods were synthesized by precipitation conversion method using basic magnesium chloride nanorods as raw materials.Through drying kinetics experiments,the drying rate curves and drying temperature curves of magnesium hydroxide nanorods were obtained at different drying medium temperatures and bed-layer thicknesses,respectively.Results indicate that the drying rate of magnesium hydroxide nanorods increases and the drying time decreases with increasing of drying medium temperatures and decreasing of bed-layer thicknesses of the wet material.When the drying medium temperature is lower and/or the bed-layer thickness of the bed is thicker,each drying rate curve of Mg(OH)2 nanorods at a certain drying medium temperature and/or a certain wet material bed-layer thickness exhibit four stages of a setup period,a constant rate drying period,a first falling rate drying period and a second falling rate drying period;and with increasing of drying medium temperatures and decreasing of bed-layer thicknesses of the wet material,the constant rate drying period ranges become gradually smaller until they disappear.The figures of drying rate curves of Mg(OH)2 nanorods may fall into four areas: the setup drying area,the constant rate drying area,the first falling rate drying area and the second falling rate drying area.

Drying kinetics experiments of magnesium hydroxide nanorods were carried out, and the drying curves as well as drying rate curves were obtained under different drying medium temperatures of 333K-513K along with the wet material bed -layer thickness of 7mm and different wet material bed -layer thicknesses of 0.5mm-7mm with drying medium temperature of 413K, respectively. The experimental data of drying kinetics were analyzed by means of thermal analysis kinetics method. And the drying differential mechanism function f(1- MR)=2MR [-MR]1/2, the drying integral mechanism function g (1-MR)=(-lnMR)1/2, the drying equation MR=exp[-(kt)2], the drying rate equation-dMR/dt =2kMR (-lnMR)1/2 as well as the drying rate constant k=Aexp [-Ea/RT]=Aexp[-Ev (1+CLL)/RT] were achieved. The pre-exponential factor A is 10.741min-1, the activation energy of interface evaporation Ev is 10.671kJ/mol, and the experimental constant CL is 100.000m-1.

Approximate expressions for the temperature integral were reviewed,which had been used in the thermal analysis kinetics for many years.Error analysis of these approximations was carried out in the domain of 5≤ u ≤100.One approximate rational expression with higher precision was selected from rational approximations;and the other approximate exponential expression was also singled out from exponential approximations,which had a low precision compared with most of the rational approximations,but was very convenient to determine the kinetic parameters(activation energy E and frequency factor A).

In this paper, the method of Multi-arc ion plating with separate targets was used to depositNb1-xAlx(0.38＜x＜0.64)/Mo1-yAly(0.6＜y＜0.78)films on the 319ss(stainless steel) by changing negative bias voltage of substrate, current of separate targets. The experimental results showed that it is available to deposit the binary alloy films by selecting suitable negative bias voltage of substrate and current of separate targets. In addition, the hot corrosion behaveor of Nb-Al films with coating Na2SO4 at 600℃ and 900℃ has been investigated, respectively. The results indicated that the performance of Nb-Al films is better than its substance 310SS in hot corrosion. The corrosion behavior of 310SS with coating Mo-Al/Nb-Al films has been studied in gas mixture of 2.3%SO2/S28.8%N2 at 600℃，results showed that corrosion resistance of sample with coating Al and Mo-Al film is better than base material, however, corrosion resistance of sample with coating Mo/Nb/Nb-Al film is worse than base material.

采用分离靶多弧离子镀技术,通过改变基片负偏压和分离靶弧电流以及镀膜时间等参数,在310SS(stainless steel)基片上制备了多种成分的Nb1-xAlx(0.38＜x＜0.64)合金薄膜.结果表明,选择适当的基片负偏压和分离靶弧电流可制得所需成分的二元合金薄膜.对所制备的Nb1-xAlx薄膜,分别做了600℃、900℃的热腐蚀实验(低温热腐蚀和高温热腐蚀),热腐蚀实验表明,该薄膜具有较好的抗热腐蚀能力.