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51.
在钼(Ⅵ),钒(Ⅴ)和钛(Ⅳ)等化合物存在下,丙烯与烷基过氧化氢的环氧化反应比传统的氯醇法有很多优点,其中以钼催化剂的性能最优,但目前报道的催化剂在反应过程中因易分解而降低了活性,并且丙烯与烷基过氧化氢的投料比过大(>3:1),丙烯循环次数过多。前文报道了钼烷基醇胺化合物对环已烯的环氧化反应,本文考察了钼烷基醇胺化合物对丙烯与叔丁基过氧化氢环氧化反应的催化性能。 相似文献
52.
Polyvinyl alcohol (PVA)-capped CdSe nanoparticles were successfully prepared by a one-step solution growth technique at room temperature and ambient pressure. X-ray diffraction, transmission electron microscopy, infrared spectra, and X-ray photoelectron spectra were used to characterize the final product. The as-prepared CdSe nanocrystals were well dispersed and uniform in shape and the diameter of the particles was confined within 8 nm. Ultraviolet-visible absorption spectra were used to study the confined growth process of PVA-capped CdSe nanoparticles. Photoluminescence measurement showed the near band-edge luminescence of the final product. 相似文献
53.
Xue-qiang Yin 《Tetrahedron》2005,61(7):1839-1843
A straightforward synthesis of (1S,2R,3R,4R)-4-(6-aminopurin-9-yl)-2-hydroxymethylcyclopentane-1,3-diol (2), an isomer of aristeromycin, and its 2′-deoxy derivative 3 from readily available disubstituted cyclopentenes is presented. An antiviral analysis of 2 showed it to have significant activity versus Epstein-Barr virus (IC50 0.62 μg/mL in the Elisa assay) and to be free of cytotoxicity effects against the host cells. In a much less comprehensive antiviral analysis, 3 also was active towards Epstein-Barr (IC50 7.58 μg/mL in the Elisa assay) but this was accompanied by cellular toxicity. 相似文献
54.
Chunfu Zhang Yongxian Wang Haibin Tian Duanzhi Yin 《Journal of Radioanalytical and Nuclear Chemistry》2002,253(2):313-316
A method for 103Pd molecular plating onto the surface of the copper rod is reported. The optimal composition of the plating bath was: palladium chloride 2 g/l, ammonium hydroxide (28%) 150 ml/l, sodium hypophosphite 12 g/l, and ammonium chloride 37 g/l. The whole procedure of 103Pd molecular plating will last 50 minutes at 40 °C. This article provides valuable experience for the preparation of 103Pd seeds. 相似文献
55.
56.
Terephthalamide derivatives as mimetics of helical peptides: disruption of the Bcl-x(L)/Bak interaction 总被引:4,自引:0,他引:4
Yin H Lee GI Sedey KA Rodriguez JM Wang HG Sebti SM Hamilton AD 《Journal of the American Chemical Society》2005,127(15):5463-5468
A series of Bcl-x(L)/Bak antagonists, based on a terephthalamide scaffold, was designed to mimic the alpha-helical region of the Bak peptide. These molecules showed favorable in vitro activities in disrupting the Bcl-x(L)/Bak BH3 domain complex (terephthalamides 9 and 26, K(i) = 0.78 +/- 0.07 and 1.85 +/- 0.32 microM, respectively). Extensive structure-affinity studies demonstrated a correlation between the ability of terephthalamide derivatives to disrupt Bcl-x(L)/Bak complex formation and the size of variable side chains on these molecules. Treatment of human HEK293 cells with the terephthalamide derivative 26 resulted in disruption of the Bcl-x(L)/Bax interaction in whole cells with an IC(50) of 35.0 microM. Computational docking simulations and NMR experiments suggested that the binding cleft for the BH3 domain of the Bak peptide on the surface of Bcl-x(L) is the target area for these synthetic inhibitors. 相似文献
57.
Changzheng Wu Qing Yang Chao Huang Ping Yin Yi Xie 《Journal of solid state chemistry》2004,177(10):3522-3528
Pure hexagonal aluminum nitride (AlN) nanowhiskers have been successfully synthesized by directly reacting AlCl3 with NaN3 in non-solvent system at the low temperature of 450 °C for 24 h. The obtained products are characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and selected area electron diffraction, which show that the obtained products are hexagonal phase AlN nanowhiskers with width from 10 to 80 nm and length up to several micrometers. The influencing factors of the formation of AlN nanowhiskers were discussed and a possible growth mechanism for AlN nanowhiskers was proposed. Additionally, the study on the corresponding optical properties and catalytic properties is also carried out. 相似文献
58.
The gold nanoprisms (GNPs) have exhibited special plasmonic properties for biomedical applications because of their unique shapes and dimensions. Based on their optical performance, the NIR dye IR780 not only enabled the GNPs-based nanosystem as SERRS nanoparticles for Raman-encoded molecular imaging, but also enhanced the plasmonic photothermal property by laser irradiation. Meanwhile, the GNPs/IR780-Lyp-1 by introduction of tumor-homing peptide segment LyP-1, which presents high affinity to p32 protein, demonstrated the increased enrichment in tumor region and enhanced photothermal therapy efficacy. 相似文献
59.
本文分析了等压实验中温度因素的影响和各种单独过程的平衡方程,理论研究得到了实验设备中的温度差和测定的平衡浓度误差的关系以及平衡方程,平衡方程也表明了各单独过程的平衡速度大小顺序为气相中的水蒸气扩散过程<气相中的水蒸气循环流动过程<试样溶液中热传导过程<热传导体中的热传导过程和试样溶液中由搅拌产生的热传递过程<溶质在溶液中的扩散过程<气液相之间的平衡过程和由压强差产生的气相的水蒸气对流过程.同时,研究表明总的平衡方程可以近似由dln|△me,b/m0|/dt=-k·mb2/(ma·wa)描述.此外研究也表明排除等压实验设备中的空气成分可以有效的加快总的平衡速度.并且实验容器与热传导体之间的接触也非常重要. 相似文献
60.
Redl FX Black CT Papaefthymiou GC Sandstrom RL Yin M Zeng H Murray CB O'Brien SP 《Journal of the American Chemical Society》2004,126(44):14583-14599
We have investigated the structural, magnetic, and electronic properties of nonstoichiometric iron oxide nanocrystals prepared by decomposition of iron(II) and iron(0) precursors in the presence of organic solvents and capping groups. The highly uniform, crystalline, and monodisperse nanocrystals that were produced enabled a full structural and compositional survey by electron microscopy and X-ray diffraction. The complex and metastable behavior of nonstoichiometric iron oxide (wüstite) at the nanoscale was studied by a combination of Mossbauer spectroscopy and magnetic characterization. Deposition from hydrocarbon solvents with subsequent self-assembly of iron oxide nanocrystals into superlattices allowed the preparation of continuous thin films suitable for electronic transport measurements. 相似文献