羧侧基聚芳醚砜醚酮酮的合成及其吸附性能

聚芳醚砜醚酮酮;羧基侧基;合成;表征;离子交换;吸附     

斜拉桥中斜拉索的面内外耦合内共振分析

研究了桥面侧振引起的斜拉索非线性振动问题。基于Hamilton原理建立了拉索的非线性振动控制方程,并利用多尺度法得到了斜拉索振动方程的二阶近似解。通过具体算例分析了斜拉索面内一阶模态与面外一阶模态相互耦合发生内共振的可能性,讨论了拉索倾斜角对拉索振动的影响,比较了在零初始条件和非零初始条件下拉索振动响应的区别。研究发现:拉索内共振发生在一定的激励频率和激励幅值区域内;改变倾斜角度,会影响拉索发生内共振时激励频率区域的大小;初始条件的不同,拉索的振动形式会相差很大。     

基于Box-Behnken法的合肥湖积软土固化配方优化的试验研究

选择CaO和纯碱作为激发剂掺入GGBS(粒化高炉矿渣微粉)制备GGBS+CaO+纯碱固化合肥湖积软土,通过无侧限抗压强度试验研究固化黏土的强度变化规律。以GGBS、CaO和纯碱的掺量作为影响因子,以7d和28d固化土的无侧限抗压强度作为响应值,基于Box-Behnken法确定3种外添剂的最佳配合比。研究表明:GGBS掺量的变化对强度响应影响最大,且其敏感程度随龄期的增大而增大;而对于CaO和纯碱,情况则相反。养护7d后,各因素对强度的线性效应和曲面效应均显著,CaO与纯碱的交互作用显著;养护28d后,GGBS与纯碱的交互作用显著。最终得出:GGBS、CaO和纯碱三掺量固化黏土最佳配比分别为13.08%、4.89%和1.25%;在最佳配合比下,7d和28d的预测强度分别达到550.904kPa和665.953kPa。最后对实测值与预测值进行了对比分析。研究成果可为在合肥滨湖地区应用矿渣类软土固化剂提供理论依据。     

三种低聚肽的物理化学性质的密度泛函研究

运用密度泛函理论对三种由不同氨基酸组成的低聚肽进行结构优化,并对其平均结合能和振动红外光谱进行分析,三种低聚肽分别为甘氨酸低聚肽、甘-丙氨酸低聚肽和甘-色氨酸低聚肽.本文主要研究,在肽链骨架相同而侧链基团不同的情况下,低聚肽的物理化学性质变化.结果表明,随着氨基酸残基数量的增加,三种低聚肽的结构稳定性都会增强,同时三种低聚肽也存在着尺寸效应,即官能团的振动都存在红移和奇偶振荡现象.侧链基团的引入会对低聚肽骨架的几何结构产生影响,在肽链生长过程中,侧链基团空间位阻大的分子优先自组装.本研究对应用红外光谱测定肽链基团和合成低聚肽等方面有一定指导意义.     

Homogeneous modification of carbon nanotubes with cellulose acetate

An efficient strategy that comprised shorten,chain extension,active groups introducing and homogeneous reaction tactics,was adopted to modify multiwalled carbon nanotubes(MWNTs) with cellulose acetate(CA).Specially,by utilizing 2,4,6-trichloro- 1,3,5-triazine,a reactive intermediate of the MWNTs(MWNT-triazine) was obtained.Suitable solubility of the MWNT-triazine helps make the homogeneous modification become reality.Detailed characterizations further verified that reaction between chloride atoms in the ...     

Synthesis of new chiral 1,2,3,4-tertrahydroisoquinoline β-amino alcohol for asymmetric diethylzinc addition to aryl aldehydes(Ⅰ)

Four new chiral 1,2,3,4-tetrahydroisoquinoline-derived β-amino alcohols were synthesized from commercially available L-DOPA. These ligands were evaluated in the asymmetric addition of diethylzinc to benzaldehydes and showed different catalytic activities(up to 86%ee).The solvent played an important role in the enantioselective process.The transition state models were proposed to explain the reversion of the product configuration.     

聚合物侧基NMR弛豫相关函数

本文导出了聚合物为链段运动时,侧基进行非等价二位置和三位置跃迁内旋转、随机自由扩散内旋转以及受阻内旋转时的NMR弛豫相关函数,同时给出了相应的谱密度函数,并讨论了两个应用实例。     

普通话轻声音节特性分析

本文讨论普通话轻声音节在音强、音长、音高和音色各方面的特性。声学分析结果表明:1.轻声音节的音强不一定弱;2.轻声音节的音长一般短于正常重读音节,大约为正常重读音节长度的五分之三左右,但内部差异很大;3.轻声音节的音高特点最为明显:失去原来的单字调型,在上声音节之后读中平调,在阴平、阳平和去声音节之后读中降调;4.轻声音节里的不带音辅音很容易浊化为带音辅音,元音普遍读得较松,但无论单元音还是复合元音,其原有音色仍可分辨。     

氧化物表面的侧表面原子成象——Ⅰ.Eu_2O_2晶体由位错滑移形成表面台阶的动态原位观察

通过高分辨电子显微术获得了Eu_2O_3晶体分子清洁的表面侧面原子成象,观察到了由表面附近位错滑移出表面而形成表面原子台阶的动态变化过程,同时还观察到了此种表面台阶的形核生长。     

Two novel fluorescent calix[4]arene derivatives with benzoazole units in 1,3-alternate conformation for selective recognition to Fe~(3+) and Cr~(3+)

Two novel fluorescent calix[4]arene derivatives 1a and 1b with benzoxazole or benzothiazole units in 1,3-alternate conformation have been synthesized and characterized by IR,~1H NMR,~(13)C NMR and MS.Their complexation properties to different heavy and transition metal ions have been studied by UV-vis spectroscopy and fluorescence spectrometer.Compounds 1a and 1b show selective recognition to Fe~(3+) and Cr~(3+).