排序方式: 共有18条查询结果,搜索用时 0 毫秒
11.
12.
13.
引言 对于某一试材,已知它边界上或内部的一些温度“和/或”热流值,来反求材料的热物性参数,这是一类热传导的反问题。关于此问题可采用非线性最小二乘法求解,并已有一些文献报道了这方面的研究。在这些文献中,侧重理论方法,实验很少。 用非线性最小二乘法测试热物性的原理可简述为:根据最小二乘法原理,由实验测得的一组温度数据与它们相对应的理论值之差的平方和为最小作为判据,来确定热物性。 相似文献
14.
15.
16.
通过对致冷剂HCFC-141b气体水合物结晶生成过程的显微观测研究,得到了水合物的结晶生成过程微观图像,认为水合物的生成是由于HCFC-141b致冷剂与水在过冷的条件下在界面接触处率先成核,成核诱导与致冷剂的扩散导致水合物不断长大,并呈现出枝状生长的现象.对水合物生成过程中不同阶段的图像进行维数计算,结果表明该水合物结晶生成过程初期属于分形生长,其生长的维数为1.52.应用分形理论,建立了HCFC-141b水合物结晶生长的RIN-DLA (Random Inducement Nucleation-Diffu-sion Limited Aggregation)模型,并对水合物的结晶生成过程进行了计算机模拟,计算并比较了实际图形和模拟图形的维数. 相似文献
17.
18.
The microscopic visualization experiment on the formation process of HCFC-141b refrigerant gas hydrate has been investigated, and the morphological photos of hydrate formation process have been obtained. The results show that gas hydrate originally nucleated on the interface of refrigerant HCFC-141b and water under the condition of supercooling, then the hydrate grows continually due to the inducement of formed nucleation and diffusion of refrigerant. The formation of gas hydrate presents an arboreous phenomenon. The fractal dimension of the hydrate formation morphology on different stages was calculated. The calculating results indicate that the initial stage of the hydrate formation belongs to fractal growth, and the dimension is about 1.52. Based on the fractal theory, an RIN-DLA (random inducement nucleation-diffusion limited aggregation) model for the HCFC-141b hydrate growth was developed. The hydrate growth process was simulated with the developed model, and the fractal dimension for the simulated 相似文献