Research progress in synthesis and catalysis of polyoxometalates

Polyoxometalates (POMs) form a large class ofmetal oxide cluster type compounds. Their wealthytopology, physical and chemical properties have at tracted increasing interests. In this paper, based onour group’s research, we review the latest progress inthe synthetic chemistry and catalysis of POMs and in troduce some POMs with novel structure and theirderivatives that emerged in 2002—2004. Most of thecited references come from those published in 2003.Due to POMs’superio…     

Nonlinear Bubbling and Micro-Convection at a Submerged Orifice

IntroductionThe behavior of bubbles,especially theirformation,interaction and coalescence,are of keyimportance in such fields as gas- liquid contact,gas- liquid separation,bubble absorption,bubblecolumns,fermentation,cavitations,etc. Theinduced fluid moti…     

Establishment and cryopreservation of liver, heart and muscle cell lines derived from the Chinese alligator （Alligator sinensis）

The Chinese alligator, Alligator sinensis, is a critically endangered species. A conservation project of gene resources for an endangered species first involves the preservation of organs, tissues, gametes, genomic DNA libraries and cell lines. The present study is the first to establish and cryopreserve cell lines of liver, heart and muscle tissues from the Chinese alligator. The study revealed that there was a large discrepancy in cell migration time in primary cultures among liver (11-12 d), heart (13-14 d) and muscle (17-18 d) tissue pieces. The differences in time in primary cell culture suggested that it was relatively easy to build visceral-derived cell lines for reptiles. Biological analysis showed that the population doubling time for thawed cells was approxi- mately 36 h. Karyotyping revealed that the frequency of Chinese alligator cells showing chromosome number as 2n=32 was 88.6%-93.4%. Chinese alligator cell lines established here provide a vital resource for research and are likely to be useful for protection of this rare and critically endangered species. Furthermore, the establishment of these methods may supply technical and theoretical support for preserving genetic resources at the cellular level for other reptile species.     

可消半模范畴中的完全可减内射分解

利用内射模与内射维数的理论,引进了可消半模上的完全可减内射分解和完全可减内射维数的概念,并给出了k-投射半模的等价刻画.     

一类亚纯系数高阶线性微分方程解的增长性

运用Nevanlinna值分布的理论和方法,研究了微分方程f(k)1Ak-1f(k-1)+…+A1f'+Af=0(k≥2)解的增长性,其中Aj(1≤j≤K-1),A为亚纯函数,假设A是以∞为亏值的超越亚纯函数,通过给定Aj(1≤j≤k-1)的不同条件,证明了齐次线性微分方程的任一非零解均为无穷级.     

配位滴定法测定汽油抗爆剂MMT中的Mn含量

阐述了配位滴定法测定汽油抗爆剂甲基环戊二烯三羰基锰(简称 MMT)的 Mn含量的原理,并对滴定条件进行了论证. MMT溶于氯仿中,然后加入溴溶液和HCl溶液进行处理以分解有机锰化合物,加热蒸去溶液中残留的溴,残渣以水胶状的酸分离出来.溶液的 pH 值可以通过 NH4Cl 和 NH3…H2O 进行调节.利用钙镁指示剂为指示剂,用 EDTA 溶液测定锰的含量,滴定终点颜色变化敏锐.该方法的 RSD 为0.11;~0.15;(n=3),平均回收率为99.56;~100.10;,方法准确、简便,可用于MMT中Mn含量的测定.     

新型薁并[1,2-f]苯并[1,4]二氮卓类衍生物的合成与表征

以1-甲酰基-2-甲氧基薁-3-甲酸甲酯为反应底物,通过与邻苯二胺缩合、烷基化、脱羧等过程,成功地制备了新型薁并[1,2-f]苯并[1,4]二氮卓类衍生物.反应收率良好、操作简单、条件温和.产物结构通过红外光谱、核磁共振谱、质谱及元素分析证实.     

1,2-二甲基-3-丁基咪唑硫酸氢盐离子液体的合成及其性质研究

介绍了在室温下设计合成的一种功能化离子液体1,2-二甲基-3-丁基咪唑硫酸氢盐离子液体[mmBim][HSO4]均为在不同温度下测定了该离子液体的密度、表面张力、粘度和电导率等性质,并根据特定的经验方程,估算了该离子液体的热膨胀系数、标准熵和晶格能等性质参数,为该离子液体的预期应用提供了重要的数据参考.     

再生骨料混凝土在新疆地区的效益分析

本文总结国内外建筑垃圾处理现状和再生骨料的应用情况;结合新疆地区的实际情况,采用对比的方法,分析新疆地区普通混凝土和再生骨料混凝土的生产成本。研究得出再生骨料混凝土具有很好的经济效益、社会效益、环保效益以及很好的市场应用前景。     

变系数 mKdV 方程的精确解

利用李群方法研究以时间为变系数的 mKdV 方程,找到了变系数方程的李代数、优化系统、相似约化、精确解.通过优化系统得到变系数 mKdV 方程的精确解.另外,借助假设的孤立波方法得到了变系数的 mKdV 方程的一个精确孤立子解