Tang Yulan

Factors Analysis for Simultaneous Biological Removal of Iron, Manganese and Ammonia from the Micro-Contaminants Groundwater

In this study a orthogonal text was performed, in order to investigate the main factor for simultaneous biological removal of iron, manganese and ammonium, and offer theoretical support for simultaneous biological removal of iron, manganese and ammonium from the micro-contaminants groundwater. Under the condition of static text, the concentration of iron, manganese, ammonia and dissolved oxygen content were put as affecting factors. The analysis of removal efficiency of iron, manganese and ammonia by SPSS analysis software shows the concentration of dissolved oxygen is the main factor affecting the simultaneous removal by the method of orthogonal text. Under the process of biological removal of iron, manganese and ammonium, appropriate dissolved oxygen content can achieve the best removal efficiency.

An Improved Molecular Dynamics Algorithm for Large Scale Simulation in Nano-Engineering

Focusing on the special need of nano-engineering, an improved neighbor list algorithm for the ultra-large scale molecular dynamics (MD) simulation is proposed. The new algorithm is attempting to fully combine the advantages of both Verlet table and cell-linked list algorithms to accelerate the speed of neighbor list construction and update. In order to meet the requirement of nano-engineering that often requires the frequent update of the cell-linked lists and neighbor lists, the program employs the pointer link data structure so that both reliability and accuracy of the simulation can be ensured. The performance of molecular dynamics simulation is evaluated using the proposed algorithm and compared with those using conventional Verlet table and cell-linked list algorithms. Results show that the new algorithm outperforms the conventional cell-linked list algorithm by 2¿3 times for systems of 104 ~ 106 atoms per single CPU.