排序方式: 共有39条查询结果,搜索用时 15 毫秒
31.
微波作用下的细粉煤脱水研究 总被引:6,自引:0,他引:6
在煤炭开采和加工工业中 ,泥煤的脱水问题变得越来越重要。改进细粉煤脱水效果的方法主要有物理方法和化学方法两类。现有的物理方法主要是提高过滤压力 ,使滤饼的结构变得致密 ,从而挤出其中的水分 ;微波加热脱水是指煤饼中的极性分子水在微波场的作用下快速摆动 ,产生类似于摩擦的作用 ,而以热的形式表现出来 ,使水分蒸发[1] 。本文是在微波加热条件下 ,探讨了微波对脱水效果的影响以及微波脱水的最佳工艺条件。1 实验部分1 1 原料 实验样品为朱仙庄气煤、山家林肥煤、西曲焦煤、青龙山瘦煤。其工业分析见表 1,其中空气干燥基水分为块… 相似文献
32.
33.
34.
Size-Dependent Melting Behaviour of Nanometre-Sized Pb Particles Studied by Dynamic Mechanical Analysis 下载免费PDF全文
Nanometre-sized (hereafter nano-) Pb particles embedded in an Al matrix are prepared by ball milling. It is found that the size of nano-Pb particles was decreased with increasing milling time. The melting behaviour of nano-Pb particles embedded in the Al matrix is studied by means of dynamic mechanical analysis, and a single internal friction peak in the vicinity of Pb melting temperature is observed. The onset temperature of the peak moves to lower temperature with the decrease of particles size and the internal friction peak height is increased, which indicates a size-dependent melting behaviour of nano-Pb particles. It is suggested that the size-dependent melting behaviour is associated with surface melting. 相似文献
35.
The temperature dependence of internal friction ( T- tan φ curves) in pure aluminium (Al) is measured at sixteen different frequencies. Based on T- tan φ curves, the frequency dependence of internal friction (f -tan φ curves) is also obtained by the interpolation method. An internal friction peak is observed in both the T - tan φ curves and the f - tan φ curves. The activation energy of the peak in the f - tan φ curves is found to be 2.08 ± 0.02 eV and compared to the value of 1.60 ± 0.04 eV in the T - tan φ curves. It is suggested that the change of relaxation strength with temperature should be considered when one calculates the activation energy of the peak in T- tan φ curves. 相似文献
36.
纳米Fe2O3的制备及其对高氯酸铵热分解的催化性能 总被引:21,自引:0,他引:21
用两相体系方法制备了纳米Fe2O3,并用X射线衍射、红外光谱和粒度分析对其结构进行了表征.结果表明,当有机溶胶的pH=6,油酸与Fe3+的摩尔比为1∶3.5时,Fe(OH)3在油相中的萃取率可高达90%,将有机溶胶在120℃回流8h后可得到非晶态、窄粒度分布的纳米Fe2O3粒子,其粒径在12nm左右.分别采用恒容燃烧热和差热分析研究了纳米Fe2O3对高氯酸铵热分解的催化性能.结果表明,在模拟固体推进剂中分别加入4.7%微米Fe2O3和4.7%纳米Fe2O3后,恒容燃烧热分别提高了2350.84和5095.70J/g.在高氯酸铵中加入5%微米Fe2O3可使高氯酸铵两个放热峰的出现分别提前1.10和62.25℃,而加入5%纳米Fe2O3时分别提前61.89和118.82℃,这说明纳米Fe2O3的催化活性优于微米Fe2O3. 相似文献
37.
Preparation and Visible Light Photocatalytic Activity for Photocatalyst of Permeable Glass Membrane/TiO2 Doped with Co 下载免费PDF全文
The photocatalyst of permeable glass membrane/TiO2 doped with Co (permeable glass membrane/TiO2 doped with Co) is prepared by the sol-gel method. The morphology and phase of the samples are determined by the field emission scanning electron microscopy (FESEM) and x-ray diffraction experiment, respectively. The photo- catalytic results show that the photocatalyst is sensitive to the visible light and exhibits excellent photocatalytic activity of photodegradation methylene blue. The photocatalytic mechanism is also discussed. 相似文献
38.
39.