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991.
贫水电解质体系制备多孔阳极氧化铝模板的研究 总被引:3,自引:0,他引:3
在有机溶剂为主的含草酸电解质中,研究了大孔径有序度高的阳极氧化铝(AAO)的一步法电化学制备.实验证实,电解质中水含量的降低能够有效抑制铝的电氧化速率和溶解速率,使得其氧化膜孔道的生长能够稳定进行,所得到的六方孔道排列有序度明显高于纯水溶剂制备的电解质体系下的产物.考察了水含量、有机溶剂种类以及电解质浓度对AAO模板孔道形貌的影响.结果表明,有机溶剂贫水电解质体系使得电氧化电压的选取范围比水溶液电解质体系更宽,孔径连续可调,反应条件温和.该方法适合于制备均匀大孔径的AAO模板. 相似文献
992.
富勒烯化聚环氧丙基咔唑的合成与表征 总被引:1,自引:0,他引:1
通过Friedel-Crrafts反应制备了富勒烯化的聚环氧丙基咔唑,聚合物中C60的含量最高可达7.6wt%。通过凝胶渗透色谱法测定了聚合物分子量,并采用^上H和^13C-NMR,IR,热分析及光谱等手段对其结构进行了分析与表征。 相似文献
993.
Mosstafa Kazemi 《合成通讯》2020,50(13):1899-1935
AbstractCatalysis research under magnetically recoverable nanocatalysts is a well-known topic in organic synthesis. In recent times, catalysis research has clearly experienced a renaissance in the area of utility of ferrite nanoparticles based on their ability to recovery and reusability. In this review, the focus is on the fabrication, characterization and of application the MFe2O4 (M=Co, Cu, and Ni) nanocatalysts in synthesis of heterocyclic structural scaffolds. 相似文献
994.
A simple, sensitive and rapid derivative spectrophotometric method using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) has been developed for simultaneous determination of Co(II), Ni(II) and Fe(II) which have very similar chemical behavior and appear together in many real samples. The complexes of all these metal ions with 5-Br-PADAP were formed immediately at pH 7.0 ammonium acetate buffered solution and were stable for at least 24 h. Second derivative spectra were selected for evaluation, because working wavelength determination was more precise and spectral overlap was less than in the ordinary and first derivative spectra. Three wavelengths at which the complexes exhibit extremum 2D values for Co(II), Ni(II) and Fe(II) were selected as analytical wavelengths, i.e., 640, 600 and 740 nm, respectively. Calibration curves drawn with zero-to-peak values at mentioned wavelengths were linear between 80 and 2000 ng ml−1 for each metal ion. Concentrations of Co(II) and Ni(II) were calculated from the total 2D values and the sum of the linear equations for these three cations at 640 and 600 nm, after Fe(II) assay by making use of the 2D value at 740 nm. Limits of detection (LOD) for Co(II), Ni(II) and Fe(II) were 2.7, 13.9 and 3.0 ng ml−1, respectively. The method has been applied to tool steel and heater resistance wire samples successfully. 相似文献
995.
Facile synthesis of 6(E)-geranylgeraniol-19-oic acid 1,a naturally occurring alicyclic diterpene acid, by a Horner-Wadsworth-Emmons olefination of two readily available fragments 2 and 3,is described. 相似文献
996.
SUN Ying LIU Shi-chun LIU Xia SONG Da-qian BI Shu-yun ZHANG Han-qi 《高等学校化学研究》2006,22(3):324-327
Introduction Humanserumalbumin(HSA)isawell known transportproteinforavarietyofmoleculesandions[1].Thebindingofadrugtoserumalbuminhasimportant pharmacokineticconsequencesbecauseitinfluences distribution,excretionandpharmacologicaleffectsof thedruginthebody… 相似文献
997.
Immobilized copper(Ⅱ) in organic-inorganic hybrid materials catalyzed Ar-N coupling of arylboronic acids with imidazoles has been developed. Arylboronic acids reacted with imidazoles smoothly in the presence of a 3-(2-aminoethylamino)propyl functionalized silica gel immobilized copper(Ⅱ) catalyst (10 mol%) in methanol without any additives and bases. The reactions generated the corresponding cross-coupling products in good yields. Furthermore, silica-supported copper can be recovered and recycled by a simple filtration procedure and used for five consecutive trials without decreases in activity. 相似文献
998.
A solid state extrusion technique is applied as to produce oriented block copoly(ether ester) under various physical conditions. The morphology of the extruded samples is characterized in relation to the extrusion parameters and hard segment compositions of the polymer, using thermal analysis and X-ray methods. The lateral dimensions of the crystalline domains are found to be approximately 150 Å depending on the extrusion conditions. The statistics of the long range periodicity of the structure along the extrusion direction is in agreement with a one-dimensional two phase model, the crystalline portion of which does not vary much in thickness (35 – 45 Å). The unexpected increase in the long period and the thermal shrinkage suggest the existence of strained interlamellar amorphous chains (tie molecules). The observed variations in tensile properties are interpreted under the assumption that both the number of such tie molecules and their fully extended lengths are determined by the hard segment composition and the extrusion conditions. It is also argued that the increase in the glass transition temperature is not only a function of the composition of hard segments in the amorphous phase but also of the number of strained tie molecules.Herrn Dr. Dr. h. c. H. Hellmann zum 70. Geburtstag gewidmet.Part 3 cf. lit [11] 相似文献
999.
1000.