高压差热分析方法（HP-DTA）研究钙蒙脱石-氯化钙-水体系中的脱水作用

在开放（P_水806 * (1000/T) (11.26M) 20%: 1np = 14.580 - 5.831 * (1000/T) (16.9M) 30%: 1np = 14.412 - 5.519 * (1000/T)根据这些等式求出了在不同压力、温度下各种浓度的CaCl_2-H_2O流体的水逸度系数（￡）。由于至目前为止在文献中还没有这方面的实验研究报道，因而无法评价这一新方法所获得的数据的准确性。利用求得的￡值，在本篇论文中建立起了不同浓度的CaCl_2-H_2O流体影响钙蒙脱石脱水温度的热力学模式：TD' = [T_1*T_D*(ΔH_(tw) + ΔH_(sv)~盐）/[T_1*(ΔG + ΔH_(dn)~水）-T_D~* (ΔH_(av)~水-ΔH_(sv)~盐）在0-1M浓度范围内，可以认为ΔH_(dh)~水≈H_(dh)~盐，等式变为：TD' = (TD*ΔH_(dh))/(ΔG + ΔH_(dh)）根据这个模式，能推导出在实验浓度范围内，钙蒙脱石在盐水体系中的脱水温度。通过本次论文的实验研究知道在一般沉积盆地的埋芷条件下，钙蒙脱石矿物不会发生简单的脱水作用。在缺乏K~+和低盐度的环境中，含水相蒙脱石可稳定地存在在一定深度的地壳中因而不可忽略蒙脱石在海洋化学和俯冲带水来源中的作用。在选择处理簇射性废料的回填料（backfill）时，如其它条件相同，则应优先选择钙蒙脱石，而不是蛭石。在石油采矿和勘探工程中，因压力释放所造成的蒙脱石的脱水作用可能是使钻井变大和塌方的可能性原因之一。

Electrophoretic migration behavior of DNA fragments in polymer solution

A newly developed polymer coil shrinking theory is described and compared with the existing entangled solution theory to explain electrophoretic migration behaviour of DNA in hydroxypropylmethylcellulose (HPMC) polymer solution in buffer containing 100 mM tris(hydroxymethyl)aminomethane 100 mM boric acid, 2 mm ethylenediaminetetraacetic acid at pH 8.3. The polymer coil shrinking theory gave a better model to explain the results obtained. The polymer coil shrinking concentration, C-s, was found to be 0.305% and the uniform entangled concentration, C+, 0.806%. The existence of three regions (the dilute, semidilute, and concentrated solution) at different polymer concentrations enables a better understanding of the system to guide the selection of the best conditions to separate DNA fragments. For separating large fragments (700/800 bp), dilute solutions (HPMC < 0.3%) should be used to achieve a short migration time (10 min). For small fragments (200/300 bp), concentrated solutions are preferred to obtain constant resolution and uniform separation. The best resolution is 0.6% HPMC due to a combined interaction of the polymer coils and the entangled structure. The possibility of DNA separation in semidilute solution is often neglected and the present results indicate that this region has a promising potential for analytical separation of DNA fragments.