nano-Particle Resonance Imaging

这是对化学工程过程（例如制药或核燃料工业中的沉淀或结晶过程）中的粒度和浓度分布的在线表征的强烈工业需求。目前可用的技术主要是取样和离线分析。没有用于纳米颗粒表征的在线设备。这些成像系统的另一个共同特征是它们测量与激发类型相同的能量形式。因此，在频域分析中，激励变量和响应变量的分离可能存在困难。这类成像方法的分辨率也受到其物理限制的限制，例如光学成像方法中激发信号的波长和强度。颗粒的大小和密度通常不同于胶体中的离子。离子携带的电荷分布随离粒子表面的距离呈指数衰减。在外力作用下，它们将以不同的加速度和终端速度运动，或者在交变力的情况下以不同的振幅和相位滞后振动。加速度和终端速度的差异，或振幅和相位滞后反映了粒子的zeta电位，大小和密度的属性。拟议的研究是利用胶体中颗粒的独特特征来间接成像纳米颗粒的特征分布。间接成像方法基于以下概念：a）由外力激励的胶体中的带电粒子的振动; B）由于带电粒子的振动而引起的能量转换; c）用于使信号强度最大化的共振原理; d）用于定位振动的断层摄影重建。该方法在分离激发变量和响应变量、关联颗粒尺寸和密度、反映颗粒间相互作用、反映颗粒间相互作用等方面具有独特的优势。d）基于激励场或响应场的分辨率选择。通过所述方法，提出的粒子共振成像（PRI）可能导致一种新的间接成像方法，并提供高度期望的和强大的在线颗粒分析工具，以满足制药，核等广泛行业的紧急需求。

This is a strong industrial demand for on-line characterisation of particle size and concentration distribution in chemical engineering processes, e.g. the precipitation or crystallisation process in pharmaceutical or nuclear fuel industries. The currently available techniques are mostly in the type of sampling and off-line analysis. There is no on-line device for nano-particle characterisation. Another common features of these imaging systems is that they measure the same form of energy as the type of the excitation. Therefore, it may have difficulties in the separation of the excitation and responding variables in the use of the frequency domain analysis. The resolution of this type imaging methods is also constrained by their physical limitation, e.g. the wavelength and intensity of the excitation signal in optical imaging methods.The size and density of particles are normally different from those of ions in colloids. The distribution of charges carried by ions is in exponential decay with the distance from the particle surface. Under an external force, they will move with different acceleration and terminal speeds, or vibrate with different amplitudes and phase lags in the case of an alternating force. The differences in the acceleration and terminal speeds, or the amplitudes and phase lags reflect the properties of particles' zeta-potential, size and density. The research proposed is to utilise the unique features of particles in colloids for indirect imaging of characteristic distribution of nano-particles. The indirect imaging method is based on the concepts ofa)the vibration of electric charged particles in colloids energized by an external force;b)the energy conversion due to the vibration of charged particles;c)the resonance principle for maximising the signal strength;d)the tomographic reconstruction to position the vibration. The proposed PRI method has unique advantages at a)the separation of excitation and responding variables;b)the correlation of particle size and density;c)the reflection of particle-particle interaction;d)the resolution selective based on either excitation or responding field.Through the appreciated approach, the proposed Particle Resonance Imaging (PRI) may lead to a new indirect imaging method and provide a highly desirable and powerful on-line particle analysis tool to meet the emergent requirement from pharmaceutical, nuclear and other wide range industries.