排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
The mechanism of thermal decomposition of rare earth acetate hydrates(Ln(Ac)_3·nH_2O,n=5,forLn=La;n=4,for Ln=Pr→Lu,Y,except Pm)has been studied by TG-DTG,DSC,infrared spectra,X-raydiffraction and chemical analysis.The thermal decomposition reaction consists of two stages,one is dehydrationand the other one is decompostion.The final product is oxide.It has been found that the temperature of pro-ducing anhydrous acetates decreases with increasing atomic number of rare earth elements.The activation ener-gies for dehydration and decomposition reaction of rare earth acetate hydrates have been calculated byFreeman-Carroll and Kissinger method.The dependence of activation energy Jor dehydration reaction on theatomic number of rare earth elements shows“inclined‘W’effect”.The enthalpy changes for dehydration anddecomposition reaction have been determined. 相似文献
2.
3.
4.
5.
<正> 热敏电阻是利用半导体材料在一定温度范围中logR与l/T显示出良好的线性关系制成的器件。高温热敏电阻是指使用温度在300℃以上的热敏电阻器。 由于高温热敏电阻温度系数非常大,输出信号强、灵敏度高等优点。国外早在50年代初为了测定喷气发动机的温度就开始了这方面的研究,到70年代为了防止汽 相似文献
6.
The zheroal deco呷osirion of YZfqO了),·10丛0 in steam aroo动here has been srudied如TG analysis.丑不尸erimenral results show rhaz with the inereaslns of te呷erature,YZf二O,)了·IOHZO graduallx releasesswater脚oleculesformlns stable玛(qo、),·2从O,and rhen the deco呷osition rate动creases at 420℃.乙口‘t,lhro叮h unslable noncryslal玛OZCO了,cubie玛O了Particles in size ofo刀I一0.0了群m areformed ar石JO℃.ItProvides a zheorerieal basisforPreParlns uirrafine玛O,in steam atmosPhere. 玛(几… 相似文献
7.
8.
9.
10.
一、前言: 混合稀土氧化物在高温下能生成稀土间的ABO_(3o)型化合物但只有当两个稀土离子半径相差较大的情况下才能实现。例如La能和Ho—Lu,Ce能和Tm—Lu生成稳定的化合物,而Pr和Yb就只能生成亚稳态 相似文献