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11.
采用纳米化学技术制备了新型的纳米复合固体超强酸催化剂SO42-/ZrO2-Fe2O3,并用XRD、TEM进行了表征.结果表明:所研制的SO42-/ZrO2-Fe2O3催化剂为晶态纳米粒子,平均粒径为30 nm,分散性较好;当活化温度为580℃,反应温度为75℃,n(硝酸)/n(苯)=2,m(苯)/m(催化剂)=20,催化反应时间5 h时,硝基苯收率可达89.6%. 相似文献
12.
XI Jingyu QIU Xinping ZHU Wentao & CHEN Liquan Department of Chemistry Tsinghua University Beijing China 《中国科学B辑(英文版)》2005,48(6)
All solid-state lithium polymer batteries may be one of the best choices for the future electrochemical power source, characterized by high energy densities, good cyclability, reliability and safety[1,2]. Owing to its potential capability to replace the t… 相似文献
13.
The effect of polystyrene sulfonic acid (PSSA) macromolecules on the polymerization of acrylamide (AM) has been studied. It was found that the rates of polymerization of AM were greatly increased in the presence of PSSA in the polymerization system.The maximum value of the rate of polymerization of AM was obtained when the ratio of [—SO_3H]: [AM] reached 3:1. When the insoluble crosslinked PSSA was used instead of the soluble one, this effect decreased considerably. The interaction between molecules of PSSA and AM was determined by infrared spectroscopy, elementary analysis and X-ray photoelectron spectroscopy. The combination form, —SO_3-NH_3~ CO—, formed between sulfonic group and amide group was found to be existed since the infrared absorption band of —NH_2 shifted from 3400cm~(-1) to 3150 cm~(-1), the binding energy of electron N_(18) changed from 399.7 eV to 401.3 eV, and the atomic ratio of N to S of the products was similar to the ratio of reagents. Based on these experimental results, the mechanism of AM polymerization in the presence of PSSA is proposed. The initial step is the combination of AM with sulfonic group to form —CONH_3~ , then followed by polymerization on the PSSA macromolecule. The role of PSSA on the polymerization of AM is discussed. 相似文献
14.
The organic nanoparticles of a blue-light-emitting molecule, 1,3-diphenyl-5-(9-anthryl)-2-pyrazuline, were prepared by reprecipitation method using acetonitrile as the solvent for the molecular precursor. Three morphologies, spherical, doughnut-shaped and cubic, could be observed on the silicon substrate forthe nanoparfides by the volume-controlled addition of acetonitrile. The evolution of particle morphology as a function of acetonitrile addition was attributed to the variation of the growth habits of the particles in the different environment. The nanoparticles exhibit the novel photoluminescence spectra as compared to those of monomer and the bulk crystals. 相似文献
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在pH 4.10的Britton-Robinson缓冲溶液中,肝素与碱性吩噻嗪染料硫堇形成离子缔合物时,染料发生明显的褪色。体系吸光度的降低与肝素钠浓度成正比,肝素的质量浓度在0~60μg/25 mL范围内符合比耳定律,摩尔吸光系数为3.58×106L.mol-1.cm-1。研究了表面活性剂和共存物质的影响,表明方法选择性好。用于肝素钠注射液效价的测定,相对标准偏差小于3%,回收率为96.5%~101.9%。 相似文献
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The superstructure and properties of polymers might be improved and enhanced througl intermolecular complexation. In this paper, the preparation, structure and properties of P(MMA-MAA)/PEO intermolecular complex through hydrogen bonding are studied. By acid hydrolysis of PMMA, a series of P(MMA-MAA) copolymers have been prepared, the MAA content of which depends on the temperature and time of hydrolyzation. In case the MAA content in P(MMA-MAA) is beyond 0.4 mole fraction, the hydrogen bonding between P(MMA-MAA) and PEO is strong enough to form intermolecular complex. The supermolecular structure of the complex is quite different from that of its constituent, which was observed by an X-ray diffraction and transmission electron microscope. The crystallization of PEO is confined owing to complexation. The complex exhibits quite a lot of good properties in thermal stability, gas permeability as well as mechanical strength, and could be used in many fields. 相似文献
19.
CuO/γ-Al2O3 catalysts were prepared by plasma treatment and conventional impregnation methods. The catalytic combustion of two kinds of volatile organic compounds (VOCs), toluene and benzene, were carried out over these CuO/γ-Al2O3 catalysts. The surface properties of these catalysts were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The experimental results showed that in catalytic combustion the activity of the CuO/γ-Al2O3 catalyst prepared via plasma was much higher than that of the CuO/γ-Al2O3 catalyst prepared by conventional impregnation method. XRD results showed that an enhanced dispersion had been achieved with the plasma treatment. SEM results indicated that the size became much smaller and the surface became more uniform with the plasma treatment. 相似文献
20.
Ning GUO Guang Fu ZENG Shi Quan XI Changchun Institute of Applied Chemistry Academia Sinica.Changchun 《中国化学快报》1993,(3)
The perovskite type of compound [n-C_(11)H_(23)N_3]_2ZnCl_4(abr.C_(11)Zn)exhibits two solid-solid phasetransitions at T_(c1)=298.7 K and T_(c2)=360.1 K.A temperature dependence study of Raman spectra of C_(11)Znprovides the evidence of occurence of the structural phase transition related to the dynamics of thealkylammonium ions.The room temperature phase is ordered and contains the all-trans alkyl chains.Theintermediate temperature phase presents a partial conformational disorder and liquidlike state of allconformational disorder occurs at high-temperature phase. 相似文献