聚甲基丙烯酸甲酯单分子膜的原子力学显微镜研究

报道了利用原子力显微镜（ＡＦＭ）技术对聚甲基丙烯酸甲酯（ＰＭＭＡ）单分子膜进行分子结构水平的观察研究．由ＡＰＭ图像中得到的ＰＭＭＡ单体所占面积与用π－Ａ曲线中换算出液面上ＰＭＭＡＬａｕｇｍｕｉｒ膜中单体的面积符合得很好．从ＡＦＭ图像中可见ＰＭＭＡＬＢ膜中ＰＭＭＡ的线型碳链是与档板（ｂａｒｒｉｅｒ）平行的紧密排列，与ＬＢ提膜方向相垂直．并由此对ＰＭＭＡＬＢ膜的形成过程进行分析．此外，还观察到了在Ｓｉ基底上ＰＭＭＡ直链的卷绕伸直排列形态，初步分析了其形成原因．     

LiAgSO4-Al2O3复合电解质的导电性研究

研究了分散第二相α－Ａｌ２Ｏ３对ＬｉＡｇＳＯ４的离子导电性的影响，发现ＬｉＡｇＳＯ４－Ａｌ２Ｏ３的电导率随ａ－Ａｌ２Ｏ３含量的增加而升高，在３００－５００℃间电导率高于纯ＬｉＡｇＳＯ４，ａ－Ａｌ２Ｏ３含量摩尔比约为４０时最高。ＴＧ－ＤＴＡ和ＸＲＤ分析表明，在高温稳定的体立心ＬｉＡｇＳＯ４降温后以Ａｇ２ＳＯ４的正交β相形式存在，但在Ｈ２Ｏ存在下，生成Ｌｉ２ＳＯ４．Ｈ２Ｏ和Ａｇ２ＳＯ４．ＦＴ－ＩＲ分析     

Separation of ephedrine stereoisomers by molecularly imprinted polymers--influence of synthetic conditions and mobile phase compositions on the chromatographic performance

Separation of ephedrine stereoisomers by molecularly imprinted polymers was performed to study the factors that affect the selectivity and column efficiency. The polymer synthesized with pentaerythritol triacrylate as the cross-linker and chloroform as the porogen was found to have the best overall separation performance. Investigation of the recognition mechanism by NMR and chromatographic analysis revealed that the major binding forces between the polymer stationary phase and ephedrine are the ionic and hydrogen bonding interactions. Studies of the influence of mobile phase compositions on the HPLC analysis have shown that a methanol-aqueous buffer was the suitable mobile phase for the separation in which pH, ionic strength and water content can be adjusted to optimize the chromatographic analysis.     

聚（甲基丙烯酸甲酯—二甲基二烯丙基氯化铵）的合成及表征

以水和乙醇作混合溶剂，用逐步滴加甲基丙烯酸甲酯的方法，通过自由基聚合，由溶解性和共聚活性差异较大的两种单体ＭＭＡ和二甲基二烯丙基氯化铵合成了新型含阳离子共聚物聚，并用ＩＲ和＾１Ｈ－ＮＭＲ进行了分析表征。该共聚物溶于丙酮和水组成的二元溶剂，并与Ｐ（ＭＭＡ－ＭＡＡ）有较强的分子复合能力。     

Oxidative entry to α-oxy N-acyl aminals and hemiaminals: efficient formation of 2-(N-acylaminal) substituted tetrahydropyrans

An efficient new method to synthesize α-oxy N-acyl aminals and hemiaminals in a single step from readily synthesized N-acyl enamines has been developed using PhI(OAc)₂ as the oxidant. The reaction conditions are very mild and the products are obtained in good yields (65-92%). A possible mechanistic pathway is laid out.     

The Purification of Glucose Type Glycosyl Nitrate and the Synthesis of Spacer—armed N—Acetyllactosamines and Their Dimers

Our previous paper1,2reported the results of selective synthesis of mannose type glycosides and their dimers in our attempt to synthesize derivatives of N-acetyllacto- samine, which could have potential activity of anti-metastasis3. Further studies on the glycosylation of the accepters exploiting glycosyl nitrate instead of the acetate as donor showed interesting chemoselectivity between the two kinds of donor, namely, the glucose type and the mannose type. The reactivity difference of the t…     

四氯合锌酸二（正十二烷基铵）晶体相变机理的付里叶变换红外光谱研究

采用变温红外光谱研究了层结构标题配合物的固。固相变机理；相变主要与烷烃链和－ＮＨ＿３极性端基结构变化有关，主要来源于烷烃链的堆积结构和构象的有序。无序变化，同时伴有Ｎ－Ｈ…Ｃｌ氢键强度的降低，由于在高温烃链产生ＧＴＧ＋ＧＴＧ＇和临近端基的ＴＧ构象以及ＧＧ链段，链大量扭曲，形成了烷烃链的“熔化”态，发现同相和异相Ｃ－Ｃ伸缩振动频率对烷烃“链熔化”相变很敏感，可用于表征烷烃链的链长变化。     

Carbon anode materials from polysiloxanes for lithium ion batteries

Three kinds of silicon-containing disordered carbons have been prepared by pyrolysis of polysiloxanes with different amounts of phenyl side groups. X-ray powder diffraction, X-ray photoelectron spectroscopy and electrochemical capacity measurements were performed to study their behaviors. Graphite crystallites, micropores, and silicon species affect their electrochemical performances. All of them present high reversible capacities, >372 mAh/g. Since the graphite crystallites are very small, they contribute very little to reversible capacity. The number of micropores produced by gas emission during the heat-treatment process decides whether they exhibit reversible capacity. Si mainly exists in the form C–Si–O and influences the irreversible capacity. There is no evident capacity fading in the first ten cycles, indicating promising properties for these disordered carbons.     

Quinazolines and 1,4-benzodiazepines. XLVI. Photochemistry of nitrones and oxaziridines

The cyclic nitrones 7-chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one 4-oxide ( 5a ) and 1,3-dihydro-7-methylthio-5-phenyl-2H-1,4-benzodiazepin-2-one 4-oxide ( 5b ) are photoisomerized to readily isolable oxaziridines, 7-chloro-4,5-epoxy-5-phenyl-1,3,4–5-tetrahydro-2H-1,4-benzodiazepin-2-one ( 6a ) and 4,5-epoxy-5-phenyl-1,3,4,5-tetrahydro-7-methylthio-2H-1,4-benzo-diazepin-2-one ( 6b ). Oxaziridine 6b upon further irradiation gave ring expansion and ring contraction products, 4,6-dihydro-2-phenyl-9-methylthio-5H-1,3,6-benzoxadiazocin-5-one ( 7b ) and 4-benzoyl-3,4-dihydro-6-methylthioquinoxalin-2(1H)-one ( 8b ) respectively. The ring contraction product, 4-benzoyl-6-chloro-3,4-dihydroquinoxalin-2(1H)-one ( 8a ), was obtained from irradiation of oxaziridine 6a .     

Recognition of single nucleotide polymorphisms using scanning potential hairpin denaturation

Conventional single nucleotide polymorphism (SNP) assays, which based their detection on the stringency or temperature of the washing buffers, have encountered difficulties to distinguish a single base pair mismatch from a perfect match. In this study, scanning potential hairpin denaturation (SPHD) has been developed to detect SNP in a sensitive and reliable manner. Combined with hairpin oligonucleotide probes, scanning surface electric potential was used to induce a dissociation of double-stranded DNA around a unique "melting potential" (Vm), and it generated a high-contrast SNP recognition signal. A 21 base pair p53 gene segment was used to test this novel method. A single nucleotide mismatch to the hairpin probes caused an average of 400-800 mV difference in melting potential against the perfect match, while the error of this assay was lower than 20 mV. Experiments demonstrated that the hairpin stem was critical to the method. The concept of scanning potential hairpin denaturation could also be used extensively in different areas of nucleotide hybridization based assays.