With the aid of the critical size of colloidal cluster, the critical volume fraction of phase transition of colloidal system is determined by the principle of entropy maximum and Carnahan-Starling （CS） state equation in this paper. In our discussion, no parameter is introduced externally, and our results are in good agreement with the experimental results.
The description of complex configuration is a difficult issue.We present a powerful technique for cluster identification and characterization.The scheme is designed to treat and analyze the experimental and/or simulation data from various methods.The main steps are as follows.We first divide the space using face or volume elements from discrete points.Then,we combine the elements with the same and/or similar properties to construct clusters with special physical characterizations.In the algorithm,we adopt an administrative structure of a hierarchy-tree for spatial bodies such as points,lines,faces,blocks,and clusters.Two fast search algorithms with the complexity lnN are generated.The establishment of the hierarchy-tree and the fast searching of spatial bodies are general,which are independent of spatial dimensions.Therefore,it is easy to extend the method to other fields.As a verification and validation,we applied this method and analyzed some two-dimensional and three-dimensional random data.
ZHANG GuangCai,XU AiGuo,LU Guo & MO ZeYao National Key Laboratory of Computational Physics,Institute of Applied Physics and Computational Mathematics,Beijing 100088,China
In a colloidal system confined by a small cylindric pipeline, the depletion interaction between two large spheres is different to the system confined by two plates, and the influence on depletion interaction from the pipeline is related to both the size and shape of it. In this paper, the depletion interactions in the systems confined by pipelines of different sizes or different shapes are studied by Monte Carlo simulations. The numerical results show that the influence on depletion force from the cylindric pipeline is stronger than that from two parallel plates, and the depletion force will be strengthened when the diameter of the cylinder is decreased. In addition, we also find that the depletion interaction is rather affected if the shape change of the pipeline is slightly changed, and the influence on depletion force from the shape change is stronger than that from the size change.
A method of studying a non-equilibrium x-ray laser plasma is developed by extending the existing one-dimensional similarity equations to the case of two-dimensional plasma study in the directions perpendicular to the slab and along a focal line. With this method the characteristics of pre-plasma are optimized for transient neon-like Cr x-ray laser. It is found that when the duration and the intensity of 1.053μm pre-pulse are 1.2 ns and 6.5 TW/cm^2 respectively with a delay time of 1.5 ns, the temperature and the temperature discrepancy each approach a proper state, which will provide a uniform distribution of properly ionized neon-like Cr ions before the arrival of pumping pulse.
