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901.
We reported in this paper FTIR linear diehroic spectroscopy and anisotropic properties of the nanoparticulate α-Fe_2O_3-stearate alternating Langmuir-Blodgett films (Fe_2O_3-St LB films) a new inorganic-organic quantum superlattice system. A new method fitted to inorganic-organic alternating films is used to study the molecular orientation and discuss the order arrangement of the nanopartieles in the films. The the results show that a configuration of stearate ions bound to the surface of the nano-particles: COO~- group are spherically bound to the surface of the nanoparticles; the hydrocarbon chains are almost perpendicular (31°±5°) to the substrate (7 nm-Fe_2O_3-St LB films). The orientation of hydrocarbon chains and CH_2 scissors vibration show the existence of trans-zigzag planar structure for C—C broken bone of the hy7drocarbon chains, which is related to high-order structure of the alternate films. 相似文献
902.
以ZnO纳米柱阵列为模板, 采用溶胶-凝胶法制备出TiO2/ZnO和N掺杂TiO2/ZnO的复合纳米管阵列. 扫描电镜(SEM)、X射线光电子能谱(XPS)和紫外-可见漫反射吸收光谱(UV-Vis)的结果表明: 两种阵列的纳米管均为六角形结构, 直径约为100 nm, 壁厚约为20 nm; 在N-TiO2/ZnO复合纳米管阵列中, 掺入的N离子主要是以N-Ox、N-C和N-N的形式化学吸附在纳米管表面, 仅有少量的N离子以取代式掺杂的方式占据TiO2晶格O的位置; 表面N物种形成的表面态能级和取代式掺杂导致带隙的窄化, 增强了纳米管阵列的光吸收效率, 促进了光生载流子的分离. 光催化实验结果表明, N离子的掺杂有利于N-TiO2/ZnO复合纳米管阵列光催化活性的提高. 相似文献
903.
V. A. Dorokhov L. S. Vasil'ev N. Kyu Khoa N. Kong Hao V. S. Bogdanov 《Russian Chemical Bulletin》1997,46(11):1967-1969
A method for the synthesis of 2,2′-bipyridin-4-one from 4-amino-4-(2-pyridyl)-but-3-en-2-onevia its diphenylboron, chelates was proposed.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2071–2073, November, 1997. 相似文献
904.
Yuh-Wern Wu 《中国化学会会志》1996,43(6):507-509
The relative rates for the addition reactions of tert-butyl radical to 2-substituted ally chlorides I have een determined. The correlation of log k/k0, vs. σm gives a ρ mvalue of 3.59 with correlation coefficient of 0.930. When the substituent CH2Cl is excluded, correlation coefficient raises to 0.990 and ρ value becomes 3.39. The large p value and the deviation of relative rate of substituent CH2C1 are discussed. 相似文献
905.
Poly(4-methyl-1-pentene) (PMP) hollow fiber membranes were prepared by the melt-spun and cold-stretch(MSCS) method. Scanning electronic microscopy (SEM) was used to characterize the section and surface structures of themembranes with special asymmetric structure. The preliminary results of gas permeation measurements indicated that the resultant hollow fiber membranes have the potential ability for oxygen/nitrogen separation. 相似文献
906.
Zhiming Liu Jiming Hao Lixin Fu Tianle Zhu Junhua Li Xiangyu Cui 《Reaction Kinetics and Catalysis Letters》2003,80(1):45-52
SnO2/Al2O3 catalyst prepared by sol-gel method showed higher activity than those prepared by impregnation method, and their activity
was significantly improved by pre-treatment in the reaction gas. The increased activity is closely related to the agglomeration
of SnO2 species and the re-exposure of Al2O3, which was previously covered by dispersed SnO2 species.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
907.
以硫酸盐为原料,添加NaOH和NaHCO3以制备出碱式碳酸盐前驱体,合成出新型的纳米固体超强酸催化剂SO42-/ZnFe2O4,经XRD、BET、IR等检测,粒径为35nm,比表面积很大(137m2-1),粒度均匀。首次以该固体酸为催化剂,癸二酸和无水乙醇为原料合成癸二酸二乙酯,考察了影响反应的因素。结果表明,醇酸摩尔比为4.0∶1,催化剂用量为1.0g(癸二酸0.1mol),带水剂苯15mL,反应时间2.5h是最佳反应条件,酯化率可达91%,并推断出该催化剂的酸强度-16.02< Ho< -14.52. 相似文献
908.
首先以2-溴-1-(2,3,4-三甲氧基)苯乙酮,四丁基铵-1H-1,2,4-三唑或咪唑为原料,分别合成了2-(1H-1,2,4-三唑-1-基)-1-(2,3,4-三甲氧基)苯乙酮(Ia)和2-(1H-咪唑0-1-基)-1-(2,3,4-三甲氧基)苯乙酮(Ib)与盐酸羟胺反应生成2-(1H-1,2,4-三唑-1-基)-1-(2,3,4-三甲氧基)苯乙酮肟和1-(1H-咪唑-1-基)-1-(2,3,4三甲氧基)苯乙酮肟,产率为63%-72%,并经元素分析,IR和1H NMR进行了表征。 相似文献
909.
Jijun Qiu Weidong Yu Xiangdong Gao Xiaomin Li 《Journal of Sol-Gel Science and Technology》2007,44(3):235-239
Ordered porous TiO2 films, including TiO2 nanotube arrays, are fabricated by a sol-gel dip-coating approach via ZnO nanorod templates obtained from aqueous solution
approach. The results indicate that the morphologies of ordered porous TiO2 films have been great affected by the sol-gel dip-coating cycle number. Open-ended TiO2 nanotube arrays can be obtained in optimum dip-coating cycle numbers. The TiO2 nanotubes with the inner diameter matching well with the diameters of ZnO nanorods, are well assembled and separate each
other. When the cycle number is less than this optimum value, no intact porous TiO2 film can be obtained. As the cycle number is larger than this optimum value, an ordered porous TiO2 film with many throughout holes is formed. The evolutive mechanism of ordered porous TiO2 films is proposed. 相似文献
910.
Xiucheng Zheng Xiaoli Zhang Shuping Wang Xiangyu Wang Shihua Wu 《天然气化学杂志》2007,16(2):179-185
In this work, we have reported the influence of the addition of base (KOH) on the physicochemical property of ceria synthesized by alcohothermal process, and the alcohothermal mechanism was also put forward. Furthermore, the prepared CeO2 was used as the support to prepare CuO/CeO2 catalysts via the wet impregnation method. The samples were characterized by N2 adsorption-desorption, X-ray powder diffraction (XRD), high resolution transmission electron microscopy (HRTEM), and temperature-programmed reduction by H2 (H2-TPR). The catalytic properties of the CuO/CeO2 catalysts for low-temperature CO oxidation were studied using a microreactor-GC system. The crystal size of CeO2-A was much smaller than that of CeO2-B, and the corresponding copper oxide catalysts exhibited higher catalytic activity than that of the CeO2-B-supported catalysts under the same reaction conditions. The alcohothermal mechanism indicated that KOH plays a key role in determining the physicochemical and catalytic properties of ceria-based materials. 相似文献