A recyclable fluorous organocatalyst for Diels-Alder reactions

Chiral fluorous imidazolidinone catalyst 2 provides consistently high enantioselectivities in Diels–Alder reactions of dienes and ,β-unsaturated aldehydes. The catalyst can be readily separated from the reaction products by fluorous solid-phase extraction, and recovered in excellent purity for direct reuse.     

水相中乙醇对胶体泡沫性质的影响

用不同比例的水-乙醇混合物作水相制备了胶体泡沫（CLA）,实验观察并测定了CLA的形态、粒径分布、半衰期、Zeta电位、水相溶液的粘度和水相/油相之间的界面张力等性质.结果表明，水相中加入乙醇会影响CLA的稳定性和粒径大小,但对CLA的Zeta电位影响不大.乙醇对CLA稳定性的影响主要是由于乙醇分子嵌入到界面膜中导致膜的强度变化以及水相粘度发生变化导致CLA粒子间隙的排液过程发生变化.     

星状四芳胺类空穴传输材料的合成

有机电致发光器件 (ＯＥＬＤ)是继阴极射线管平板显示器 (ＣＲＴ)和液晶显示器 (ＬＣＤ)之后的第三代平板显示器。它具有主动发光、驱动电压低(2伏左右 )、发光亮度高 (1 3 0 0 0ｃｄ ｍ2 以上 ) ,无软Ｘ 射线污染 ,响应速度快 (1 0 -6 ～ 1 0 -8秒 )等优点。从 1 987年美藉华人邓清云等提出多层结构的ＯＥＬＤ的器件结构以来的十多年间 ,ＯＥＬＤ以及其材料的研究已成为显示技术以及显示材料等方面的研究热点 ,发展很快[1～ 3] 。在 1 999年日本先锋公司已开发出了单色的汽车用ＯＥＬ平板显示器商品 ,今年东芝公司又开发出了 2 .7英寸的彩…     

Cell detection based on protein array using modified glass slides

A protein array for cell detection was fabricated by spotting different antibodies on modified glass slides. Glass slides were modified to allow antibodies to be immobilized on it and to selectively bind antigens. Antibodies were specially selected with the cells to be detected as targets, which permitted target cells in samples to bind specifically to the array with little nonspecific binding. Results can be obtained by directly putting the samples onto the array for 1 h or a little longer to let the cells specifically interact with the antibodies. After washing the unbound samples away, images were observed with a microscope and captured with a CCD camera. The assessment of antibody-cell binding was evaluated by capturing red blood cells (RBCs) in human blood with blood group antibodies (anti-A and anti-B). Blood group antibodies were spotted on the modified glass slide and kept at 4<.deg> degrees C overnight for immobilization. Human blood samples diluted to different concentrations were used to examine the sensitivity and specificity of the method.     

New selective O-debenzylation of phenol with Mg/MeOH

Carboxylate-benzyl and nitro-benzyl groups used in phenols protection were selectively debenzylated with 3-25 equiv of Mg in methanol at room temperature. Good yields of the desired phenols were obtained within 3-10 h from a wide variety of O-(carboxylate-benzyl)- or O-(nitro-benzyl)-phenols. Selective O-debenzylation was possible in the presence of O-(carboxylate-benzyl)- or O-(nitro-benzyl)-phenols with Mg/MeOH.     

Studies on the Physicochemical Properties, Structure and Antitumor Activity of an Oligosaccharide Homologue SnS-2 from the Root of Scrophularia ningpoensis Hemsh

An oligosaccharide homologue named SnS-2 was isolated from the root of Scrophularia ningpoensis Hemsl.SnS-2 was purified by means of gel-permeation chromatography and ion-exchange chromatography. Its physicochemical properties, including carbohydrate content and molecular weight were determined. The structure of SnS-2 was elucidated by chemical methods along with ^1H and ^13C NMR spectroscopy, including two-dimensional DQCOSY and H-detected ^1H, ^13C HMQC experiments. These results show that SnS-2 possesses a backbone consisting of terminal α-Galp-(1→, α-Galp-(1→6), α-Glcp-(1→6) and nonreducing end β-Fruf-(2→. The bioactive assay showed that it could inhibit the growth of Lewis pulmonary carcinoma implanted in mice.     

On the copolymerization of acrylates in the modified microemulsion process

Copolymerization of methyl methacrylate, methyl acrylate, butyl methacrylate, and butyl acrylate in turn was performed in the modified microemulsion polymerization process, i.e., continuous addition of monomer to a preemulsified system. It was found that the particle size of the copolymer microlatex did not change distinctly with the monomer composition. The estimation of emulsifier coverage on the microlatex particles indicated that the process switched from a traditional microemulsion to a normal seeded emulsion polymerization very soon after monomer dropping began. Therefore, a longer dropping time is needed to produce a microlatex with narrow dispersed particle size. Besides, in the modified microemulsion polymerization less emulsifier is needed to produce a stable microlatex. This behavior is related to the mechanism of normal seeded emulsion polymerization during monomer dropping.     

直流放电制备CN自由基及其LIF探测

CN自由基是研究化学反应动力学的典型自由基，CN的动力学行为，如CN＋O2的反应已成为研究自由基－自由基反应的模型体系[1]，同时也在许多实际过程如燃烧过程，星际气体的形成过程中起着重要的作用[2，3]．利用含有CN的化合物进行光解、放电、与亚稳态原子分子进行传能反应是目     

负载型非晶态Cu/SiO2催化剂的非晶性质

以超细ＳｉＯ２为载体，用ＫＢＨ４还原Ｃｕ＾２＋盐溶液制备了非负载型Ｃｕ和负载型Ｃｕ／ＳｉＯ２催化剂，ＸＲＤ，ＴＥＭ和电子衍射分析结果表明，负载型Ｃｕ／ＳｉＯ２为完全非晶态，而非负载型Ｃｕ中存在着少量晶态Ｃｕ，ＤＳＣ结果表明，非晶态Ｃｕ／ＳｉＯ２的热稳定性明显高于非负载型Ｃｕ，说明超细ＳｉＯ２具有稳定非晶结构的作用，ＸＰＳ结果表明，还原产物中的铜原子呈Ｃｕ状态，ＩＣＰ分析结果表明，样品中的Ｂ含量均低     

基于离子液体的炭材料制备、改性及应用

离子液体因其熔点低、液态温域宽、蒸气压低、热稳定性高、电导率高、电化学窗口宽、结构可设计及对许多化合物的亲和性等系列性能而引起人们广泛关注。离子液体在炭材料制备、改性领域展示出了良好的前景及巨大的应用潜力,可直接作为碳源,经过高温炭化实现杂原子掺杂制备多孔炭材料;离子液体也可充当反应介质和致孔剂,将生物质转化为多孔炭材料;此外,由于离子液体与炭材料相容性较好,可以用于多孔炭材料改性制备炭复合材料。基于离子液体的炭材料在电催化、超级电容器、吸附分离及生物医学等领域具有潜在的应用价值。本文总结了基于离子液体炭材料的制备、改性及应用最新研究进展,并着重介绍了其在能源和环境相关领域的应用。