高中化学"问题解决"课堂教学模式的研究与实践

"问题解决"教学模式是在新课程理论学习和对课堂教学实践深入思考的基础上提出来的,它把化学教学作为一个整体的研究对象,站在学生和教师共同发展的角度,以"问题解决"的思维模式进行教与学的双重研究.在实际教学中进行有目的、有意识的"问题解决"课堂教学设计与教学实践的初步尝试的基础上,提出了一些值得思考、又有困惑的问题.     

N-二氯乙酰基噁唑烷合成反应的薄层色谱法研究

用薄层色谱法监测了用二氯乙酰氯、醇胺和酮合成的除草剂的安全剂N 二氯乙酰基 口恶唑烷的反应过程。方法操作简便、快速、准确。     

松香基功能高分子吸附分离盐酸小檗碱研究

探索了聚马来松香己二醇酯(PMHE 树脂)和马来松香乙二醇丙烯酯-丙烯酸共聚物poly(MGAE-AA)对盐酸小檗碱的分离提纯.实验结果表明,马来松香乙二醇丙烯酯-丙烯酸共聚物吸附分离盐酸小檗碱的效果较好,最佳条件是T=80℃,pH=6.00,振荡频率为150r/min;静态吸附量为62.47mg/g,动态吸附量为3.54mg/g.使用马来松香乙二醇丙烯酯-丙烯酸共聚物吸附盐酸小檗碱,初产品中盐酸小檗碱固含量由37.53%上升到68.91%;聚马来松香己二醇酯对盐酸小檗碱的静态吸附量为8.59mg/g,动态吸附量为0.68mg/g.     

Peroxide-mediated efficient addition of cycloalkanes to imines

A novel direct addition of cycloalkanes to imines mediated by peroxide was developed. The reaction tolerates a wide range of functionalities as well as aqueous conditions.     

非晶态NdxT1-x(T=Fe,Co,Ni)薄膜的低温磁性

本文讨论了非晶态Nd_xT_1-x(T=Fe,Co,Ni)薄膜为滋结构,以及在低温下磁化强度随温度变化的反常特性,在20K附近观测到磁化强度有陡降现象,并且在较大的成份范围内所对应的温度基本不变,我们认为,在这类非晶态合金中,当Nd含量超过一定值后,其磁中性态(通称基态)可能同时是散反铁磁性和散铁磁性的共存态,在20K附近的磁化强度发生陡降,是散反铁磁性←→顺磁性相转变的反映,这两种磁结构共存的临界成份相应约为:Nd-Fe情况x≥0.45;Nd-Co,x≥0.20;Nd-Ni,x≥0.08。 关键词：     

A facile strategy to modify TiO2 nanoparticles via surface‐initiated ATRP of styrene

A core‐shell hybrid nanocomposites, possessing a hard core of nano titanium dioxide (n‐TiO₂) and a soft shell of brushlike polystyrene (PS), were successfully prepared by surface‐initiated atom transfer radical polymerization (ATRP) at 90 °C in anisole solution using CuBr/PMDETA as the catalyst, in the presence of sacrificial initiator. FTIR, ¹H NMR, XPS, TEM, SEM, TGA, and DSC were used to determine the chemical structure, morphology, thermal properties, and the grafted PS quantities of the resulting products. TEM images of the samples provided direct evidence for the formation of a core‐shell structure. The thermal stabilities of the grafted polymers were dramatically elevated relative to that of pristine PS according to TGA results. DSC results demonstrated that the TiO₂‐PS nanocomposites exhibited higher glass transition temperature (T_g) compared with pristine PS. The molecular weights of the free polymers formed by sacrificial initiator, which were similar to that of surface‐attached polymers were measured by GPC instrument which showed that the molecular weights of PS were well controlled with a relatively narrow polydispersity index (PDI < 1.2). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1782–1790, 2010     

电感耦合等离子体质谱法测定中低合金钢中痕量铝

应用电感耦合等离子体质谱法测定了中、低合金钢中痕量铝,并对质谱仪的工作条件作了优化.用微波加热消解技术对样品进行前处理,用混合比例为3比1比1的浓硝酸、浓盐酸及浓氢氟酸的混合酸作为溶解酸.对微波炉的操作程序及参数作出详细叙述.此方法的检出限为ω(Al)1.9×10-6%,对浓度水平为ω(Al)1.4×10-4%的试样进行精密度试验,其结果的标准偏差值均小于6.0%.     

赝标介子的唯象模型(Ⅱ)——电磁形状因子

本文直接以平底势计算得到的赝标介子波函数,在欧氏空间中计算出物理的0^-介子的类空电磁形状因子。数值结果表明,在适当选择参数下,理论计算的结果能和实验相符合。 关键词：     

LiF晶体中F3^＋—F2混合色心激光器

本文报道了室温下LiF晶体中F_3~+-F_2混合色心激光器.利用一块晶体和单一泵光,输出激光波长范围从510～580nm、640～710nm.总带宽140nm.     

不分明拓扑学的若干研究方向

自1968年C.L,Chang提出不分明拓扑空间的概念以来,不分明拓扑学得到了迅速的发展。从近年来发表的有关论文来看,不仅所涉及问题的面在不断扩大。而且对问题的分析讨论也在逐步深化。各个不同方向的研究都得出了一些比较深刻的结果,可以说是各有千秋。本文试图从这些纷繁的研究课题中整理出几个研究方向来,并对各方面的研究工作作一概略的分析。