Evans Robert, Timmel Christiane R, Hore P J, Britton Melanie M
Department of Chemistry, University of Oxford, Inorganic, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, UK.
J Am Chem Soc. 2006 Jun 7;128(22):7309-14. doi: 10.1021/ja0608287.
The effects of applied magnetic fields on the traveling wave formed by the reaction of (ethylenediaminetetraacetato)cobalt(II) (Co(II)EDTA2-) and hydrogen peroxide have been studied using magnetic resonance imaging (MRI) . It was found that the wave could be manipulated by applying pulsed magnetic field gradients to a sample contained in a vertical cylindrical tube in the 7.0 T magnetic field of the spectrometer. Transverse field gradients decelerated the propagation of the wave down the high-field side of the tube and accelerated it down the low-field side. This control of the wave propagation eventually promoted the formation of a finger on the low-field side of the tube and allowed the wave to be maneuvered within the sample tube. The origin of these effects is rationalized by considering the Maxwell stress arising from the combined homogeneous and inhomogeneous magnetic fields and the magnetic susceptibility gradient across the wave front.
利用磁共振成像（MRI）研究了外加磁场对由（乙二胺四乙酸）钴（II）（Co（II）EDTA2-）与过氧化氢反应形成的行波的影响。研究发现，在光谱仪7.0 T磁场中，通过对垂直圆柱管中包含的样品施加脉冲磁场梯度，可以操纵该波。横向场梯度使波在管的高场侧向下传播减速，而在低场侧向下传播加速。这种对波传播的控制最终促使在管的低场侧形成一个指状物，并使波能够在样品管内进行操控。通过考虑由均匀和非均匀磁场组合产生的麦克斯韦应力以及波前的磁化率梯度，对这些效应的起源进行了合理的解释。
