Square lamellar structure having phase-separated microdomain in H-shaped block copolymer thin film

The morphology of a H-shaped block copolymer (poly(ethylene glycol) backbone and polystyrene branches (PS)(2)PEG(PS)(2)) in a thin film has been investigated. A peculiar square lamella that has a phase-separated microdomain at its surface is obtained after spin coating. The experimental temperature plays a critical role in the lamellar formation. The copolymer first self-assembles into square lamellar micelles with an incomplete crystalline core due to the crystallizability of PEG.

稀土化学修饰电极的研究——铕(Ⅲ)的电化学行为

本文研究了铕(Ⅲ)在Nafion聚合物薄膜化学修饰电极上的电化学行为。研究结果表明,在pH5.8的醋酸缓冲溶液中,铕(Ⅲ)的氧化还原非常接近可逆过程。利用二甲酚橙的络合作用和Nafion的阳离子交换作用,在选定条件下,铕(Ⅲ)的导数波高度与其浓度在2.0×10~(-7)～1.0×10~(-5)mol/L范围内成线性关系,检出限为1.0×10~(-7)mol/L。当富集时间为10min时,检出限可达2.0×10~(-8)mol/L,Sm(Ⅲ)、Yb(Ⅲ)及其他稀土元素基本不干扰,可用于铕(Ⅲ)的分析测定。同时避免了使用汞(Ⅱ)的问题。

东太平洋海隆13°N附近沉积物中的热液活动记录

本文以东太平洋海隆13ºN附近E53沉积物岩芯为研究对象，进行了矿物学、全岩化学分析及连续提取分析，探讨了沉积物中的热液活动记录及元素存在形式，并结合已有的测年数据，对研究区域的热液活动过程进行了初步讨论。 E53岩芯分为三层，上层为红褐色沉积层，中层为棕黄色沉积层，下层为灰绿色沉积层。沉积物岩芯的X射线衍射结果显示，E53岩芯上层非晶质的铁锰氧化物含量较高，中下段方解石含量较高。根据元素在岩芯全岩及各相态间的存在状况，将常量及微量元素分组讨论。Fe、Mn元素以铁锰氧化物相为最重要的赋存相，且与全岩样品一致，呈现随深度下降趋势。Al、Ti、Ba主要存在于残留相中；K、Na、Mg主要赋存相为碳酸盐相；Ca、Sr同样主要存在于碳酸盐相中。微量元素Mo、Co、V、Cu、Zn、Ni、Y和Pb元素主要存在于铁锰氧化物相，且含量均随深度增加而下降。Th、Sc、Li和Zr的主要存在于残留相中；Cd、U主要存在于碳酸盐相中。稀土元素存在形式有以下三个特点：1、主要存在于铁锰氧化物相中，并且呈现出随深度增加含量下降的趋势；2、次要存在形式为碳酸盐相，随深度增加含量上升并一度超过残留相中的含量；3、在有机结合相和残留相中含量很低，且变化幅度不大。 根据本文讨论结果，结合前人年代数据，认为E53岩芯中记录的为程度逐步加强且在近期保持稳定的热液活动。

Genetic variation within and among populations of Rhodiola alsia (Crassulaceae) native to the Tibetan Plateau as detected by ISSR markers

Genetic variation of 10 Rhodiola alsia ( Crassulaceae) populations from the Qinghai - Tibet Plateau of China was investigated using intersimple sequence repeat (ISSR) markers. R. alsia is an endemic species of the Qinghai - Tibet Plateau. Of the 100 primers screened, 13 were highly polymorphic. Using these primers, 140 discernible DNA fragments were generated with 112 (80%) being polymorphic, indicating pronounced genetic variation at the species level. Also there were high levels of polymorphism at the population level with the percentage of polymorphic bands (PPB) ranging from 63.4 to 88.6%. Analysis of molecular variance (AMOVA) showed that the genetic variation was mainly found among populations (70.3%) and variance within populations was 29.7%. The main factors responsible for the high level of differentiation among populations are probably the isolation from other populations and clonal propagation of this species. Occasional sexual reproduction might occur in order to maintain high levels of variation within populations. Environmental conditions could also influence population genetic structure as they occur in severe habitats. The strong genetic differentiation among populations in our study indicates that the conservation of genetic variability in R. alsia requires maintenance of as many populations as possible.

南海北部陆缘深水区构造－热演化与烃源岩成熟度史研究

Abstract In order to provide basic data for evaluation of the petroleum potential in the deep water area of the northern margin of the South China Sea (SCS), present-day thermal regime and basin tectonothermal evolution are reconstructed and the maturation history of the Cenozoic major source rocks in the study area is derived. The present-day geothermal regime in the deep water area of the northern margin of SCS is defined according to the geothermal gradient, thermal properties and heat flow data. Tectonic subsidence history is reconstructed based on borehole and seismic data, and accordingly the stretching episodes are determined from the subsidence pattern. Heat flow history in the deep water area of the northern margin of SCS is estimated on a finite time, laterally non-uniform and multi-episode stretching model. Maturation history of the main source rocks in the study area is estimated through EASYRo% kinetic model and thermal history, and the potential of petroleum in the deep water area of the northern margin of SCS is evaluated based on the data above. The results show that the present-day geothermal regime in the deep water area of the northern margin of SCS is characterized by “hot basin” with high geothermal gradient (39.1±7.4℃/km) and high heat flow (77.5±14.8 mW/m2), and that the Qiongdongnan Basin (QDNB) underwent three stretching episodes and consequently suffered three heating episodes (Eocene, Oligocene and Pliocene time) with highest paleo-heat flow of 65～90 mW/m2 at the end of the Pliocene, that the Pearl River Mouth Basin (PRMB) two stretching and two heating episodes (Eocene, Oligocene time) with highest paleo-heat flow of 60～70 mW/m2 at the end of the Oligocene, and that the source rocks matured drastically responding to the heating episodes. There are four hydrocarbon generation kitchens in the deep water area of the northern margin of SCS which are favor of its bright petroleum perspective. Tectonothermal analysis indicates that the present-day geothermal regime which is characterized with “hot basin” in the deep water area of the PRMB resulted mainly from the Cenozoic stretching as well as faulting and magmatic activities during the Neotectonic period, and that the Pliocene heating episode of the QDNB is coupled with the transition from sinistral to dextral gliding of the Red Rive fault, and that the deep water basins in the northern margin of SCS are typical of multiple rifting which caused multi-episode heating process.