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101.
102.
PTC特性的复合导电体系中炭粒子分布的逾渗模型与电阻率的计算 总被引:17,自引:0,他引:17
综述了炭黑填充型导电高分子复合体系的几种导电理论;讨论了导电载流子分布的各种假说及模型;比较了不同模型的理论预测与实验结果的差异性。 相似文献
103.
Recent developments in quantitative surface analysis by Auger (AES) and x-ray photoelectron (XPS) spectroscopies are reviewed and problems relating to a more accurate quantitative interpretation of AES/XPS experimental data are discussed. Special attention is paid to consideration of elementary physical processes involved and influence of multiple scattering effects on signal line intensities. In particular, the major features of core-shell ionization by electron impact, Auger transitions and photoionization are considered qualitatively and rigorous approaches used to calculate the respective transition probabilities are analysed. It is shown that, in amorphous and polycrystalline targets, incoherent scattering of primary and signal Auger and photoelectrons can be described by solving analytically a kinetic equation with appropriate boundary conditions. The analytical results for the angular and energy distribution, the mean escape depth, and the escape probability as a function of depth of origin of signal electrons as well as that for the backscattering factor in AES are in good agreement with the corresponding Mote Carlo simulation data. Methods for inelastic background subtraction, surface composition determination and depth-profile reconstructions by angle-resolved AES/XPS are discussed. Examples of novel techniques based on x-ray induced photoemission are considered. 相似文献
104.
Effect of conditions of deposition of palladium onto a composite polymeric film Nafion—polyaniline on the properties of the system thus obtained is studied. It is shown that the effect of the said conditions on the character of distribution of palladium in a polymer may be used when estimating electrocatalytic potentialities of such composites.Translated from Elektrokhimiya, Vol. 41, No. 2, 2005, pp. 213–218.Original Russian Text Copyright © 2005 by Andreev, Zolotarevskii.This revised version was published online in April 2005 with corrections to the article note and article title and cover date. 相似文献
105.
106.
四苯硼钠-甲苯胺蓝缔合物纳米微粒体系减色效应研究 总被引:2,自引:2,他引:2
在PH4.0醋酸-醋酸钠介质中,甲苯胺蓝在600nm处有一个吸收峰,随着四苯硼钠浓度的增大甲苯胺蓝在600nm处吸收峰降低,颜色减弱,这是由于甲苯胺蓝-四苯硼钠缔合物分子间存在较强的疏水作用及分子间作用力,聚集形成纳米微粒所致,甲苯胺蓝-四苯硼钠纳米微粒体系亦在600mm处有1个吸收峰,在400mm、470mm和580mm处产生3共振散射峰,其中400mm和580mm为甲苯胺蓝-四苯硼钠复合纳米微粒产生的特征共振散射峰,这也表明有纳米微粒存在,丙酮浓度的影响实验结果等表明,纳米微粒的形成是产生其减色效应的原因。 相似文献
107.
用浸渍法制备了掺杂不同质量分数的La0.8Sr0.2Ga0.8Mg0.15Co0.05O3-δ (LSGMC5)粉末的Ni8-Fe2-LSGMC5复合阳极, 并采用交流阻抗和直流极化技术考察了以氢气和二甲醚为燃气时该复合阳极的电化学性能及相应电池的功率输出特性. 结果表明, 在电极中掺入LSGMC5 粉末, 能显著地改善电极的形貌和电极/电解质界面结构, 减小欧姆电阻和极化电阻. 电极中LSGMC5 粉末含量对于氢气及二甲醚电化学氧化性能的影响显著不同. 以二甲醚为燃气时, 电极极化电阻随LSGMC5 粉末含量的增加而减小, 其中LSGMC5 掺杂量为30%的复合阳极具有最高的电化学性能, 相应电池在1073、1023、973 K 时的输出功率分别为1.00、0.61、0.40 W·cm-2; 以氢气为燃气时, LSGMC5 掺杂量为20%的复合阳极具有最好的电化学性能, 随着LSGMC5 掺杂量的进一步增加, 电极极化电阻显著增大. 相似文献
108.
由原位缩聚制备了刚性高分子聚酰亚胺(PI)和柔性基体聚N-乙烯吡咯烷附(PVP)的分子复合物,并由实验证明了中间体聚酰胺酸(PA)和聚乙烯吡咯烷酮大分子之间存在的酸一碱相互作用.这种相互作用促进了混容性,使聚酰亚胺能以分子水平或接近分子水平分散在聚毗咯烷酮的基体之中.聚酰亚胺/聚N-乙烯吡咯烷团分子复合物的薄膜呈透明性,在整个组成范围内只有一个Tg,显示单相行为。当PI含量<20%时,SEM相片呈现均相形貌,看不到PI微晶.广角X-ray衍射图表明PI特征结晶峰消失,和无定形的PVP完全混容.当PI含量>40%,SEM显示有均匀分布的、棒状PI微晶存在.通过分子复合,即使PI含量为10%,聚N-乙烯吡咯烷酮不再溶于乙醇,耐热性也有提高. 相似文献
109.
LiNi0.8Co0.2O2 / MWNTs复合物超级电容器电极材料的研究 总被引:2,自引:0,他引:2
Multiwalled carbon nanotubes (MWNTs) were used as the conductive additive in the electrode materials. The electrochemical properties of supercapacitors based on LiNi0.8Co0.2O2 / MWNTs composite and LiNi0.8Co0.2O2/acetylene black composite and MWNTs in 1.0 mol·L-1 LiClO4 / EC+DEC [V(EC)∶V(DEC)=1∶1] electrolyte were investigated by means of constant charge/discharge current tests, respectively. The experimental results show that the LiNi0.8Co0.2O2 / MWNTs composite has better performance than that of others, and the maximum specific capacitance of the supercapacitor can reach 271.6 F·g-1, while the energy density is up to 339.5 Wh·kg-1. Furthermore, it is remarkable that the performance of MWNTs is better than that of acetylene black as the conductive additive. 相似文献
110.
Luis C. Mendes Andrea D. Tedesco Mauro S. Miranda Marcia R. Benzi Beatriz S. Chagas 《Polymer Testing》2005,24(8):963-968
In this third work, we evaluated the degree of conversion (DC) versus depth of dental filling composite named Prodigy Condensable™ using infrared spectroscopy. Confirming previous results, there was a gradual reduction of DC with increasing depth but the composite exhibited extreme values of DC, an upper value (45.9%) on the surface and a lower one (6.1%) at a depth of 5 mm. The composite presented the worst performance among materials studied. The composite formulation was 80% of inorganic fillers and BisfenolA/dimethacrylate (BisGMA) (18%)/triethyleneglycoldimethacrylate (TEGDMA) (2.0%) as monomers. As stated before, type/ratio/viscosity of monomers and type, amount, size and size distribution of fillers all together had an important role in the cure reaction contributing to the final performance of the composite. 相似文献