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HAPPY-SYNTHSIS铜虫 (小有名气)
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求助两段英文文献翻译（要专业一点）
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5.2.5. Long monolithic columns Since monolithic columns are known to exhibit a much higher permeability than packed columns having a similar separation power, their use to prepare long, highly efficient columns seems very attactive. Unfortunately, monolithic silica rods shrink during their preparation. This shrinking generates considerable internal stress in the material and at the interface between the rod and the silica tube in which it could be prepared. The interface does not stand the stress and snaps, causing leaks between the rod and the wall, letting the mobile phase bypass the monolithic bed and resulting in a large loss of retention and efficiency. Large monolith are prepared in a mold, in such a way that they do not stick to a wall, are dried, and then are encapsulated in a plastic (e.g., PEEK) tubing providing an excellent column. However, the rods are brittle. They cannot be prepared straight, so only relatively short columns are prepared in this way. Although they can be connected into longer columns, it does not seem practical to prepare long, highly efficient columns by connecting dozens of 10 cm long columns, especially due to the limited pressure that a PEEK tube can withstand. If the monolith is prepared in a capillary tube, however, the stress becomes insufficient to break the interface between the tube wall and the monolith and long capillary columns can be prepared [12,29]. Columns of various lengths and having 50– 100m i.d. were prepared. Their permeability is far higher than that of conventional columns packed with 5m particles but their efficiency is comparable with that of these columns. This would make possible the preparation and the use with conventional pumps of columns having lengths of several meters and very high efficiencies. |
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HAPPY-SYNTHSIS
铜虫 (小有名气)
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5.2.5 。长整体柱众所周知，由于整体柱和填充柱相比，有相似的分离能力，但展现出更高的渗透性，它们被用来准备更长更高效的柱子看起来非常地有吸引力。不幸的是，整体硅胶棒柱在制作过程中会产生收缩，这种收缩主要是由于制作材料以及棒柱和硅胶管接触面的内应力产生的。由于分界面不能承受应力而断裂，导致棒柱和壁间产生渗漏，使流动相从整体柱床旁流过从而使流动相的保持力和效率降低。大的整体制品是在模子里制作的，用这种方法就不会黏在壁上，干燥后被压缩到塑料管就形成了一根性能良好的柱子。但是，棒柱是易碎的，不能被制备太长，所以只有相对较短的柱子才用这种方法制备。虽然这些短柱能被连接形成更长的柱子，但是用几十个10cm长的连接起来形成更长，更高效的长整体住却是不实际的，尤其是PEEK管所承受的压力有限的情况下。 但是，当用毛细管作为整体柱的情况下，它的渗透压不足以打破管壁和整体柱之间的表面张力，从而可以制得长柱整体柱，包括50-100平方微米的各种长度的整体柱。这些整体柱的渗透压远远高于5平方微米的传统柱的，而效果却能与传统柱的相媲美。这使得不同长度的高效的传统柱泵的制备和应用成为可能。 |
2楼2009-01-12 15:21:09
HAPPY-SYNTHSIS
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3楼2009-01-12 20:08:05