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91.
本文提出用α,β,γ,δ-四-(4-吡啶)卟啉为显色剂,分光光度法测定瓷餐具铜的溶出量,该方法灵敏度高,选择性好,可以不经分离,直接对试样进行测定,操作简便,结果满意。 相似文献
92.
93.
Guo-Qiang Chen 《Journal of Polymer Research》2003,10(4):289-290
Volume Contents
Contents Volume 10 (2003) 相似文献94.
Wenjun Zhang Fangqing Zhang Yafei Zhang Guanghua Chen Xiangliu Jiang 《Diamond and Related Materials》1994,3(11-12)
Highly purified polycrystalline wafers of Zr and Hf were chosen as substrates for diamond deposition by means of the d.c. arc discharge plasma CVD method. Polycrystalline diamond films were formed on both substrates. Scanning electron microscopy and high resolution X-ray diffraction were used to investigate the surface morphology of the diamond films and the composition of the interface layers between the diamond films and substrates. The experiments showed that the transition layer between the diamond films and Zr substrates was ZrC, ZrH and ZrC0.32H1.2. For Hf substrates, in addition to HfC, it is supposed that there were also some hydrides or carbohydrides in the transition layer, because several X-ray reflections appeared which could not be assigned to Hf, HfC or diamond. 相似文献
95.
为了保证电厂的生产效率,必须要分析电气的运行特征,确定电气故障发生的原因,综合考虑多方面因素,选择切实可行的措施解决问题。简要分析了电厂电气运行常见故障发生原因,并提出了相应的解决措施。 相似文献
96.
本文由无限稀释活度系数求取混合物MH-81状态方程的二元相互作用参数,预测了二元混合物的汽液平衡,获得了较满意的结果。 相似文献
97.
Show-An Chen 《应用聚合物科学杂志》1971,15(5):1247-1266
From thermodynamic considerations based on associated solution models and from the Hansen's three-dimensional solubility parameter concept, it is found that the solvent power of an organic liquid for a given polymer can be characterized by two parameters, δh and χH, where δh is the hydrogen-bonding solubility parameter of the liquid, and χH is a term which takes account of the dispersion and polar interactions between the liquid and the polymer and of the effects due to temperature and molecular size of the liquid. It is also found that Hansen's solubility sphere for the polymer can be represented as a solubility circle in the proposed χH?δh plane. The proposed approach is applied successfully to polymer–plasticizer systems. 相似文献
98.
The effect of relative humidity on the photoin-duced curing kinetics of cyclohexyl epoxide and epoxide/polyol coating formulations
was investigated in real-time using FTIR spectroscopy. In total, five formulations were used in this study, including a cyclohexyl
epoxide without polyol, and four with polyols. The polyol formulations were varied with respect to ratio of epoxide to polyol,
and molar functionality of the hydroxyl group. The formulations were exposed to a maximum of seven different relative humidities
(6, 16, 20, 30, 51, 62, 75 RH). The curing speed and overall conversion of the epoxy group passed through a maxima for all
the formulations. The polyol had an effect on the hydrophilicity of the overall formulation. It was also found that water
and polyols had a synergistic effect on the UV-curing kinetics, in effect lowering the relative humidity to achieve a maxima.
A model for UV-curing mechanisms at low, medium, and high relative humidity was proposed for both systems with and without
the polyols.
Part of this work was done at the Polymers and Coatings Dept., North Dakota State University, Fargo, ND 58105.
Presented at the 80th Annual Meeting of the Federation of Societies for Coatings Technology, Oct. 30–Nov. 1, 2002, in New
Orelans, LA.
Dept. of Polymer Engineering, Akron, OH 44325-0301. 相似文献
99.
100.
A novel and simple growth mark method was developed to make marks during the growth process of carbon nanotube arrays. These marks can be read out under scanning electron microscope or optical microscope. Based on this method, the growth rates at different temperatures and under different acetylene partial pressures were measured, from which the activation energy and the order of reaction were determined. Based on our experimental results, the growth of carbon nanotube arrays in our experimental condition could not be diffusion-limited. The measured activation energy could possibly be attributed to the heterogeneous decomposition of acetylene over the catalyst particle. Furthermore the marked array with special segmental structure may be found some applications in the future. 相似文献