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21.
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   
22.
气固吸附等温线的研究进展   总被引:39,自引:0,他引:39  
综述了近些年来在气固吸附理论研究领域对吸附等温线的研究进展。论述了从早期的BDDT的5种类型吸附等温线,到IUPAC的6种类型吸附等温线,再到基于Ono-kondo晶格模型的Gibbs吸附分类的5种类型吸附等温线.讨论了与各种类型吸附等温线类型相对应的吸附机理,并对滞留回环现象进行了解释和分析。  相似文献   
23.
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   
24.
甲基丙烯酸三苯墓甲酯和甲基丙烯酸酯类的共聚物在溶液中的螺旋诱导和解旋作用陈传福,刘卫宏,陈永明,任长玉,习复(中国科学院化学研究所北京100080)关键词甲基丙烯酸三苯基甲酯,甲基丙烯酸甲酯,光学活性,螺旋诱导,解旋在手性阴离子复合引发剂存在下,甲基...  相似文献   
25.
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   
26.
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   
27.
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   
28.
从核磁共振氢谱推导的重质油氢碳原子摩尔比计算式   总被引:2,自引:1,他引:2  
通过对炼油厂的催化油浆、重催油浆和催化重焦蜡油核磁共振氢谱中质子归属和重质油结构的假设,推导出计算这3种重质油的氢碳原子摩尔比计算式;结果表明,氢碳原子摩尔比的计算值与实测值非常接近,平均误差仅为3.1%。  相似文献   
29.
Organic nanocrystals of 1,3,5-triphenyl-2-pyrazoline(TPP) with a series of sizes were synthesized by reprecipitation method.The luminescence quantum efficiency of TPP nanocrystals increases from 24.2% for the nanocrystals with an average size of 300nm to 34.6% for those with an average size of 20nm.Surface capping by polyvinyl pyrrolidone(PVP) will improve the quantum efficiency of TPP nanocrystals.The size-dependence and capping-induced variation of the luminescence quantum efficiency was elucidated in viewpoint of aggregation quenching and the equilibrium between the TPP monomers and the aggregates in TPP nanocrystals.  相似文献   
30.
The components of the rock, the pigments, the gold foils and the adhesive of One Thousand Hand Buddha in Dazu stone sculptures, Chongqing, China, have been analyzed by X-ray diffraction (XRD), X-ray fluorescence (XRF), infrared spectroscopy (IR), energy dispersive X-ray analysis (EDX) and fiber optics reflectance spectroscopy (FORS). Furthermore, the weathering and degeneration of One Thousand Hand Buddha have been discussed and the protective methods have been provided. In this work some useful information to study on conservation of stone relics is given.  相似文献   
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