Uniform State Distribution Research Articles

Progress of intense heavy ion beam driven high energy density physics

Intense ion beams can quasi-isometrically heat any high-density sample and generate warm dense matter (WDM) with large scale, uniform state distribution without any shock wave inside. This kind of driver provides a new opportunity for the laboratory high energy density physics (HEDP) research. The typical intense ion beam accelerators around the world, as well as their critical parameters and research plans of HEDP study are introduced.The progress of ion driven WDM generation and evolution using PIC and hydrodynamic simulations is shown. The high energy electron beam radiography technique with high spatial resolution, high temporal evolution, and high penetrating ability is also introduced. The collisional and charge transfer processes of the interaction between low-to-medium energy ion and plasma are analyzed. The nonlinear effect during the intense ion beam stopping and transportation process are presented.

On the number of driver nodes for controlling a Boolean network when the targets are restricted to attractors

It is known that many driver nodes are required to control complex biological networks. Previous studies imply that O(N) driver nodes are required in both linear complex network and Boolean network models with N nodes if an arbitrary state is specified as the target. In order to cope with this intrinsic difficulty, we consider a special case of the control problem in which the targets are restricted to attractors. For this special case, we mathematically prove under the uniform distribution of states in basins that the expected number of driver nodes is only O(log2N+log2M) for controlling Boolean networks, where M is the number of attractors. Since it is expected that M is not very large in many practical networks, the new model requires a much smaller number of driver nodes. This result is based on discovery of novel relationships between control problems on Boolean networks and the coupon collector’s problem, a well-known concept in combinatorics. We also provide lower bounds of the number of driver nodes as well as simulation results using artificial and realistic network data, which support our theoretical findings.

Trajectory studies of energy transfer: CH 3NC with He, Xe, H 2 and N 2

A trajectory program was used to simulate the collisions of CH 3NC with He, Xe, H 2 and N 2. Calculated energy transfer is in accord with experiment. The pattern of CH 3NC vibrational mode energization is found to be noticeably non-random. The approximate sampling methods used in thermal unimolecular trajectory studies produce a more uniform state distribution.