Structural competition between the G-quadruplex, the I-motif, and the Watson-Crick duplex has been implicated for repetitive DNA sequences, but the competitive mechanism of these multistranded structures still needs to be elucidated. We investigated the effects of sequence context, cation species, and pH on duplex formation by the G-quadruplex of dG3 (T2AG3) 3 and its complement the I-motif of d (C3TA2) 3C3, using ITC, DSC, PAGE, CD, UV, and CD stopped-flow kinetic techniques. ITC and PAGE experiments confirmed Watson-Crick duplex formation by the complementary strands. The binding constant of the two DNA strands in the presence of 10mM Mg2+ at pH 7.0 was shown to be 5.28 107 M-1 at 20℃, about 400 times larger than that in the presence of 100 mM Na+ at pH 5.5. The dynamic transition traces of the duplex formation from the equimolar mixture of G-/C-rich complementary sequences were obtained at both pH 7.0 and pH 5.5. Fitting to a single-exponential function gave an observed rate of 8.06 10-3 s-1 at 20℃ in 10mM Mg2+ buffer at pH 7.0, which was about 10 times the observed rate at pH 5.5 under the same conditions. Both of the observed rates increased as temperature rose, implying that the dissociation of the single-stranded structured DNAs is the rate-limiting step for the WC duplex formation. The difference between the apparent activation energy at pH 7.0 and that at pH 5.5 reflects the fact that pH significantly influences the structural competition between the G-quadruplex, the I-motif, and the Watson-Crick duplex, which also implies a possible biological role for I-motifs in biological regulation.

The mesoporous silica/alumina membrane was prepared by the template-tailored sol-gel method, using the surfactant of cetyltrimethyl ammonium bromide (CTAB) as the template. Further a novel procedurewas explored to synthesize free-standing mesoporous silica oriented by the self-assembles of surfactants. Characterization of SEM and BET indicated that this free-standing silica films had good development of mesoporosity and a special asymmetric structure, which make it not only an attractive materials for preparing new types of catalysts, medical carriers and chemical sensors, etc. but also has promising applications in manufacturing asymmetric mesoporous membranes.

包括表面活性剂在内的大分子在溶液中可以形成聚集体的特性，使其在工业和生活领域得到广泛的应用。研究其自组装特性对生命体内两亲大分子的聚集行为以及生物矿化和仿生合成的研究均具有重要意义。本文分别从分子热力学和分子动力学的角度，对以表面活性剂为主的大分子自组装特性计算机模拟的研究进展进行了综述，分析并展望了对大分子溶液体系理论模拟研究的发展前景。

本文综述了自组装单层膜制备及应用技术的最新发展，分别对有机硅烷/羟基化表面和硫醇/金两种重要的自组装单层膜体系的制备新技术以及在制膜技术和分子电子学等领域的最新应用进行了总结。

Performances of BaTi1-xNixO3 perovskites, prepared using sol-gel method, as catalysts for partial oxidation of methane to syngas have been studied. The catalysts were characterized by XRD, BETand TEM. The experimental studies showed the calcination temperature and Ni content exhibited a significant influence on catalytic activity. Among catalysts tested, the catalyst BaTi0.8Ni0.2O3 exhibited the best activity and excellent stability.