Zingsheim H P
J Microsc. 1984 Mar;133(Pt 3):307-12. doi: 10.1111/j.1365-2818.1984.tb00495.x.
Sublimation rates of ice in the nitrogen-filled cryochamber of an ultramicrotome have been measured. The values are four to five orders of magnitude smaller than vacuum sublimation rates at the same temperature. This is a consequence of the much shorter mean free path length of water molecules in nitrogen at atmospheric pressure, as compared to freeze drying under vacuum. The partial pressure at the phase boundary and gas diffusion and convection determine the rate of freeze drying. This has implications for section handling and the design of transfer equipment. Generally, it means that the danger of even partial dehydration of semithick (0.5-1 micrometer) sections used mainly for X-ray microanalysis is less serious than commonly assumed.
已测量了超薄切片机氮气填充冷冻室中冰的升华速率。该值比相同温度下的真空升华速率小4至5个数量级。这是由于与真空冷冻干燥相比，在大气压下氮气中水分子的平均自由程要短得多。相界面处的分压以及气体扩散和对流决定了冷冻干燥的速率。这对切片处理和转移设备的设计有影响。一般来说，这意味着主要用于X射线微分析的半厚（0.5 - 1微米）切片即使出现部分脱水的危险也没有通常认为的那么严重。
