Liu Yun, Chen Wei-Ren, Chen Sow-Hsin
Department of Nuclear Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
J Chem Phys. 2005 Jan 22;122(4):44507. doi: 10.1063/1.1830433.
We present a different and efficient method for implementing the analytical solution of Ornstein-Zernike equation for two-Yukawa fluids in the mean spherical approximation. We investigate, in particular, the conditions for the formation of an extra low-Q peak in the structure factor, which we interpret as due to cluster formation in the two-Yukawa fluid when the interparticle potential is composed of a short-range attraction and a long-range repulsion. We then apply this model to interpret the small angle neutron scattering data for protein solutions at moderate concentrations and find out that the presence of a peak centered at Q=0 (zero-Q peak) besides the regular interaction peak due to charged proteins implies an existence of long-range attractive interactions besides the charge repulsion.
我们提出了一种不同且高效的方法，用于在平均球近似下实现双 Yukawa 流体的 Ornstein-Zernike 方程的解析解。我们特别研究了结构因子中形成超低 Q 峰的条件，我们将其解释为当粒子间势由短程吸引和长程排斥组成时，双 Yukawa 流体中形成团簇的结果。然后我们应用该模型来解释中等浓度蛋白质溶液的小角中子散射数据，发现除了带电蛋白质产生的常规相互作用峰外，在 Q = 0 处有一个峰（零 Q 峰），这意味着除了电荷排斥外还存在长程吸引相互作用。
