| 查看: 1694 | 回复: 4 | ||
siximeiwen铜虫 (正式写手)
|
[求助]
有没有人可以解释下扩散和弥散的区别? 已有1人参与
|
| RT |
» 猜你喜欢
武汉纺织大学-材料科学与工程学院-姜伟杰青团队-招生物方向调剂
已经有0人回复
武汉纺织大学-材料科学与工程学院-招 生物方向 硕士!
已经有0人回复
有机高分子材料论文润色/翻译怎么收费?
已经有126人回复
武汉纺织大学-材料科学与工程学院-姜伟杰青团队-招生物方向调剂
已经有0人回复
[武汉纺织大学]材料学院[姜伟团队名称]课题组-2026年硕士研究生调剂信息
已经有0人回复
武汉纺织大学-材料科学与工程学院-姜伟杰青团队-招调剂
已经有0人回复
生物医学材料前沿科普:低密度、高孔隙率的“多孔微球”核心技术与应用全景
已经有1人回复
湖南工业大学周贵寅组招生物医学工程(学硕07、08都行)、生物与医药(专硕08)硕士生
已经有0人回复
湖南工业大学周贵寅组招生物医学工程(学硕07、08都行)和生物与医药(专硕08)硕士生
已经有0人回复
考研求调剂
已经有0人回复
2026年中南民族大学化学与材料科学学院调剂公告
已经有30人回复
» 本主题相关价值贴推荐,对您同样有帮助:
细菌RNA提取后跑电泳出现一条暗带和在泳道中弥散都是什么原因?
已经有9人回复
二次PCR产物弥散
已经有12人回复
3‘RACE inner PCR 电泳结果总是有弥散现象回收条带不成带状什么原因啊?
已经有17人回复
怎么用居里外斯定律表征压电陶瓷弥散相变程度?
已经有10人回复
这弥散带该咋办呢?
已经有5人回复
SDS-PAGE后面几条带弥散求助
已经有15人回复
SDS-PAGE电泳,菌液总蛋白,染色后显示的是弥散的
已经有5人回复
【求助/交流】PCR产物电泳条带弥散???
已经有30人回复
【交流】沉淀强化和弥散强化的共同点与区别
已经有12人回复
【求助/交流】PCR以前能出来目的条带,现在一直弥散,诸位帮忙分析一下
已经有4人回复
【求助/交流】Takara试剂盒,合成cDNA看不到弥散,着急啊
已经有16人回复


2楼2011-12-12 22:16:19
静水四叶草
金虫 (小有名气)
小笨蛋精灵
- 应助: 4 (幼儿园)
- 金币: 1343.7
- 散金: 9
- 红花: 5
- 帖子: 257
- 在线: 46小时
- 虫号: 1117555
- 注册: 2010-10-09
- 性别: MM
- 专业: 理论和计算化学

3楼2011-12-13 09:14:03
静水四叶草
金虫 (小有名气)
小笨蛋精灵
- 应助: 4 (幼儿园)
- 金币: 1343.7
- 散金: 9
- 红花: 5
- 帖子: 257
- 在线: 46小时
- 虫号: 1117555
- 注册: 2010-10-09
- 性别: MM
- 专业: 理论和计算化学

4楼2011-12-13 10:46:12
【答案】应助回帖
|
扩散diffusion,弥散dispersion Diffusion and dispersion are different modes of mass transfer in that the mechanisms behind them are different. Diffusion is the spreading out of material that occurs due to the random thermal motion of molecules, and is characterized by molecules behaving as "random walkers". In order to understand dispersion, consider a convective flow superposed over the diffusion. If the flow velocity is uniform everywhere (i.e. "plug flow" , then molecules at different places in the flow will move with the same convective velocity, and it is only diffusion rate which will differentiate between them. However, now consider a flow in which gradients exist, for example fully developed pipe flow. The fluid at the center of the pipe is moving much faster than the fluid close to the walls. If there is diffusion in the radial direction, then molecules can hop over from one streamline to the next, and thereby will be transported over different distances due to the difference in velocities. This smearing out (or being transported over different distances) caused indirectly by diffusion (in the radial direction) is the physical interpretation of dispersion. Surprisingly, the amount of dispersion reduces with increasing diffusion coefficient. This is because, then, the molecules will just be hopping from one streamline to another constantly and will not get "enough" time to be transported far from each other. The above physical model of dispersion is explained beautifully in the book "Analysis of Transport Phenomena" by William M. Deen. You should have a look, if possible!——QUORA http://www.zhihu.com/question/23914350/answer/55768081 来源:知乎 |
5楼2016-03-25 09:08:55














回复此楼
, then molecules at different places in the flow will move with the same convective velocity, and it is only diffusion rate which will differentiate between them. However, now consider a flow in which gradients exist, for example fully developed pipe flow. The fluid at the center of the pipe is moving much faster than the fluid close to the walls. If there is diffusion in the radial direction, then molecules can hop over from one streamline to the next, and thereby will be transported over different distances due to the difference in velocities. This smearing out (or being transported over different distances) caused indirectly by diffusion (in the radial direction) is the physical interpretation of dispersion. Surprisingly, the amount of dispersion reduces with increasing diffusion coefficient. This is because, then, the molecules will just be hopping from one streamline to another constantly and will not get "enough" time to be transported far from each other. The above physical model of dispersion is explained beautifully in the book "Analysis of Transport Phenomena" by William M. Deen. You should have a look, if possible!