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实验方法的翻译！很急！
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2.7. Zeta potential measurements Zeta potential measurements were conducted by laser doppler electrophoresis using the Nano-S Zetasizer equipped with a 2mW helium neon laser with an output of 633nm. Zeta potential is a measure of the net charge on a particle and depends on the charge on the particle plus the charge of associated with any ions that move along with the particle in an electric field (Surh, Decker, &McClements, 2006). An applied potential of 150V and a modulation frequency of 250 Hz were used. The instrument was calibrated with a standard carboxyl modified polystyrene latex solution, with a surface potential of 55 mV, provided by Malvern Instruments. Zeta potential was calculated from the Helmholtz–Smoluchski equation: zeta potential d ¼ m4pZ/E, where m is the electrophoretic mobility or velocity at unit potential gradient, Z is the viscosity of the liquid, and E is the dielectric constant. The dielectric constant of water at 22 1C was taken as applicable while sample viscosities were measured at 22 1C as described in Section 2.7. Samples were measured 20 times. The sample count rate was generally 2000 times higher than the background count for distilled and deionised water (filtered). For zeta potential determination, the results were expressed in absolute values (mV). |
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qqglory
铁杆木虫 (正式写手)
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落花往事(金币+20,VIP+0):非常感谢！你英语很棒，如果可以能留个QQ吗，想多向你请教一下！ 12-29 08:46
落花往事(金币+20,VIP+0):非常感谢！你英语很棒，如果可以能留个QQ吗，想多向你请教一下！ 12-29 08:46
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电动电势的测量： 电动电势是通过利用激光多普勒电泳法来测量的，要用到装备有2mw的633nmd 氦激光的纳米级的粒径分析仪。电动电势是测量颗粒净电荷的一种方法，它测量的是颗粒电荷加上在电流作用下流经颗粒的离子电荷。目前用到的是电压150V，频率250Hz.仪器通过羧基改性聚苯乙烯溶液进行校准（溶液表面电势为55mv，由莫尔文仪器提供）。电动电势通过亥姆霍兹等式来计算：电动电势d ¼ m4pZ/E，其中m是单位势梯度下的电泳淌度或速率，E为介电常数。当溶液的粘度如2.7章所讲的那样在221C下测量的，那么221C下的介电常数可以在实验中采用。试样经过了20次测量。样品计数率要比用于蒸馏过滤水溶液的本底计数率大2000备。在电动电势的测量中，最终结果要用绝对值表示（MV）。 |
2楼2009-12-28 22:01:59
qqglory
铁杆木虫 (正式写手)
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3楼2009-12-29 08:50:01