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961.
Effect of low-molecular-weight organic anions on electrokinetic properties of variable charge soils 总被引:1,自引:0,他引:1
It is known that some inorganic anions can be adsorbed by variable-charge soils specifically, resulting in the lowering of the zeta potential of the clay particle. Reasoning similarly, organic anions should also have such an effect. In this article, the effect of the anions of five low-molecular-weight (LMW) organic acids existing widely in soils on the zeta potentials of two variable-charge soils was examined. The results showed that the presence of organic anions led to a decrease in zeta potential. The effect of different anions on zeta potential followed the order oxalate>citrate>malate>maleate>acetate. The effect increased with the increase in anion concentration and decreased with the increase in pH. The extent of the effect on different soils was apparently related to their iron oxide content. The presence of organic anions also led to a decrease in the isoelectric point (IEP) of the soil. The IEPs of two soils in organic anion systems followed the order acetate>maleate>malate>citrate. No IEP was detected for the oxalate system. 相似文献
962.
Incineration methods are becoming increasingly important from the view point of the need to minimize the environmental impact of waste tyre disposal. Combustion of waste tyre, one high ash coal and tyre-coal blends with 10, 30 and 50% waste tyre were investigated by means of thermogravimetric analysis (TGA) carried out at 20 K min−1 in the temperature range from ambient temperature to 1273 K. And effects of the mixed proportion between coal and waste tyre on the combustion process, ignition and burnout characteristics were also studied. The results indicate that the combustion of waste tyre is controlled by the emission of volatile matter, the regions are more complex for waste tyre (three or more peaks) than for coal (one peak). Also as compared with the case of burning only high ash coal, the incorporation of waste tyre can improve the combustion characteristics of high ash coal, especially the ignition performance and the peak weight loss compared with the separate burning of waste tyre and coal. Moreover, comparisons of the TG-DTG profiles between experimental and calculational results, it is indicate that there is a comparatively important difference, the co-combustion characteristics is the coupling effect between waste tyre and coal. The data resulting also showed that the co-combustion of waste tyre and low quanlitied coal as fuel is feasible. 相似文献
963.
Two-dimensional infrared (2D IR) correlation spectroscopy was applied to study the structural changes occurring in the decomposition of PHEA-co-MMA/SiO2. Complicated absorption spectral changes were observed in the heating process. 2D IR analysis indicates that during heating, covalent bonds, (Si-O-C), between the polymer and the inorganic moiety were formed, which was the main factor in the improvement in thermal properties of the hybrids such as the decomposition temperatures (Td). The thermal stability of the hybrids was also studied by solid-state 29Si MAS NMR spectroscopy and TGA tests. Their results complemented each other well. 相似文献
964.
Low-energy coherent charge-density wave excitations are investigated in blue bronze (K(0.3)MoO(3)) and red bronze (K(0.33)MoO(3)) by femtosecond pump-probe spectroscopy. A linear gapless, acousticlike dispersion relation is observed for the transverse phasons with a pronounced anisotropy in K(0.33)MoO(3). The amplitude mode exhibits a weak (opticlike) dispersion relation with a frequency of 1.67 THz at 30 K. Our results show for the first time that the time-resolved optical technique provides momentum resolution of collective excitations in strongly correlated electron systems. 相似文献
965.
Jing Xu Yibao Li Lejia Wang Xiaoyang Zhu Xunwen Xiao Yanfang Geng Ke Deng Qingdao Zeng 《中国化学快报》2019,30(3):767-770
Because of the effect of pyridine on the substituent position on the TTF group, TTF derivatives exhibit different assembly structures at the interface, which will be of great significance to the construction of functional nanostructures from the molecular design point of view. 相似文献
966.
流动分析法同时测定铬(Ⅵ)及铬(Ⅲ)过程中铈(Ⅳ)氧化剂的影响 总被引:3,自引:0,他引:3
以Ce(Ⅳ)为氧化剂,采用流动分析在线氧化技术,实现了对Cr(Ⅵ)和Cr(Ⅲ)的同时在线分析,发现Ce(Ⅳ)氧化剂在测定过程中产生负干扰,在而Cr(Ⅲ)存在时会使Cr(Ⅵ)的测定结果偏高,本文提出了一个校正模型,通过数学方法消除上述干扰,所建立的分析方法对Cr(Ⅵ)和Cr(Ⅲ)分析的平均相对误差不大于6.5%。 相似文献
967.
We have developed a method that makes use of dual isosbestic points in a dual ligand, single metal system that allows the determination of the equilibrium constants of complexes in which two ligands compete for the same metal ion, and one complex is colourless. The competition of methyl thymol blue and citrate was used to test the model. 相似文献
968.
969.
用中国计量科学院提供的量热基准苯甲酸标定了本实验室建立的精密静弹燃烧热量计,测定了四邻甲氧基苯基卟啉(T_(o—OCH_3)PP)和四对二甲氨基苯基卟啉(T_(p—N(CH_3)_2)PP)的标准燃烧能,并计算出标准生成焓。实验仪器等温环境潜水式静弹燃烧热量计,量热环境主要包括恒温水槽和量热筒外套两部分,水槽中的两个泵式搅拌器能使水槽中的水充分搅动。量热体系包括量热筒、筒内定量的水、氧弹、内加热器、内搅拌器、热敏电阻测温探头以及一支辅助检测温度计。量热 相似文献
970.
采用INDO方法计算了{Fe[P(OMe)_3]_3(C_8H_(13))}~+的简化离子[Fe(PH_3)_3(C_8H_(13))]~+,将正则分子轨道用Edmiston-Ruedenberg定域化方法变换为定域分子轨道,结果表明:在对应C_1-H_(1A)键的定域分子轨道中,明显包含有铁原子轨道成分(7.8%),Fe-H_(1A)和Fe—C_1键级分别为0.190和0.302。指出C_1-H_(1A)键是以一对成键σ电子配位到铁原子上的。C_8H_(13)环以包含三个碳原子的η~4—共轭体系与铁原子相互作用。铁以二价(d~6-Fe(Ⅱ)的形式存在于该离子中。C_1-H_(1A)键的配位满足了文献[15]提出的Fe(Ⅱ)的共价12价。 相似文献