薄层色谱展开机理的探讨

It is found by experiment that the mobile phase at the front of plate moves faster than that at the back ofplate at the same moment.So,a new explanation can be put forward as follows:Upon the thin layer plate sur-face,tliere is an attachment layer of mobiie phase,formed due to wetting force and surface tension。The at-tachment layer is not equithickness everywhere, but the aheader,the thiner.     

Y-Ba-Cu(Cr)氧化物超导体

我们在Y-Ba-Cu-O系中得到零电阻温度Tcf为94.1K,中点转变温度Tc为95K,起始转变温度Tci为100K,转变宽度△Tc为1K的超导体。低温X光衍射结构分析结果表明,多相超导体在低温区(123—173K)有相变。因此,我们认为Y-Ba-Cu-O系中多相超导体的高Tet是低温相变引起的,并不完全是超导转变点。在该系氧化物中以Cr取代1/3的Cu,仍然得到Tcf=82.8K、Tc=83.5K、Tci=92K、△Tc=1K的超导体。