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Abstract SERS has been used as a state-resolving probe to study the adsorption states. in the case of pyridine (Py) adsorbed on the Ag electrode surface, the equilibrium and transition between two adsorbed states, i.e., the perpendicular mode adsorbed through the nitrogen lone-pair electrons and the flat mode through the π electrons of the aromatic ring, were studied. It was found that in the low pyridine concentration or the initial stage of adsorption, the flat mode was favored. While the concentration became higher and the adsorption tended to equilibrium, the adsorbed molecules would transit to the perpendicular mode. The similar phenomenon was also observed when changing the applied electric potential and the pH value of the solution. In the case of the adsorption of Methylene Blue (MB) on the HNO3-etched silver surface, the influence of Cl? ions on the adsorption states of MB was investigated. It showed that MB molecules adsorbed on the silver surface tended to transform from the “lying-down” state to the “end-on” state while adding Cl? ions. 相似文献
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The structure effects of polymers on the relationship between sol fraction and radiation dose arediscussed in detail. In consideration of the deviation of experimental results from Charlesby-Pin-ner's and Chen-Liu-Tang's expressions relating sol fraction to radiation dose, we introduced an ex-ponent βconcerned with the structure and property parameters of a polymer (glass transition tem-perature T_g and molecular internal rotating steric factor δ) and assumed that the fracture density isproportional to R~β(R is radiation dose). Thus, a general expression, formula (9), relating solfraction to radiation dose is derived. When β=1 andβ=0.5, this expression is reduced to the above-said two expressions. Us-ing this general expression, the experimental data of a number of polymers are treated. It is shownthat the expression is in good agreement with the experimental results, βvalue is in the range of 0. 5 to1.0. 相似文献
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In the present work, radiation crosslinking of different branched poly (vinyl acetate) have beemstudied and the validity of the relationship between sol fraction and radiation dose: R(S+S~(1/2)=1/U_(1qo)+p′_o/q_oR~βto branched poly(vinyl acetate) have been assured. 相似文献
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CHARACTERIZATIONOFRADIATIONGRAFTCOPOLYMEROFINORGANICCOMPOUNDONTOALKENEZhangWanxi;CheJitai;YanMeilan(ChangchuninstituteofAppli... 相似文献
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交联聚丙烯酰胺吸水凝胶的强度 总被引:1,自引:0,他引:1
高吸水材料是一类新型的功能高分子材料,已有广泛开发和应用。本文讨论了含大量无机填料膨润土的阴离子型交联聚丙烯酰胺(JSWAM)吸水凝胶的强度及其形态结构。 吸水材料JSWAM的制备:将填料搅拌分散于丙烯酰胺水溶液中,同时加入规定量的甲叉基双丙烯酰胺、过硫酸铵、碱,而后聚合并水解。将聚合物胶块造粒、烘干、粉碎。凝胶强度 相似文献
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In this paper, calculating the molecular internal rotating steric factor of polymers by the radiation crosslinking method is studied and a relationship between the molecular internal rotating steric factor (σ) and crosslinking parameter βis established~([1]) by taking account of the effect of polymer chain flexibility on βvalue, σvalue of polymer obtained by this method is in agreement with that given with other method. 相似文献
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富勒烯化聚环氧丙基咔唑的合成与表征 总被引:1,自引:0,他引:1
通过Friedel-Crrafts反应制备了富勒烯化的聚环氧丙基咔唑,聚合物中C60的含量最高可达7.6wt%。通过凝胶渗透色谱法测定了聚合物分子量,并采用^上H和^13C-NMR,IR,热分析及光谱等手段对其结构进行了分析与表征。 相似文献
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Yiguo Zhu Dan Zhao Liang Ying Ping Hu Ying Chang Wanxi Zhang 《Acta Mechanica Solida Sinica》2014,27(6):579-587
The effects of strain, strain rate and temperature on the mechanical behavior of 22MnB5 boron steel deformed isothermally under uniaxial tension tests and the experimental characterization of 22MnB5 boron steel in the austenitic region have been investigated. Based on the crystal plasticity theory and thermal kinematics, an improved integration model is presented. In this model, the elastic deformation gradient is the integration variable of the governing equation, which contains not only the elastic deformation but also the thermal effects. In the coupled thermo- mechanical process, this model can reveal the evolution of microstructures such as the rotation of a single crystal and the slip systems in each of them. The plastic behavior of the boron steel can be well described by the presented model. 相似文献