The effects of electric dipole moment, the number of dipolar particles, and system temperature on the structures and dynamics of a dipolar dust particle system are studied by molecular dynamics simulations. The results show that the larger electric dipole moment is favorable for the formation of a long-chain structure, the larger number of dipolar dust particles promotes the formation of the multi-chain structure, and the higher system temperature can cause higher rotation frequency. The trajectories, mean square displacement (MSD), and the corresponding spectrum functions of the MSDs are also calculated to illustrate the dynamics of the dipolar dust particle system, which is also closely related to the growth of dust particles. Some simulations are qualitatively in agreement with our experiments and can provide a guide for the study on dust growth, especially on the large-sized particles.

Linear polyubiquitin chains regulate diverse signaling proteins, in which the chains adopt various conformations to recognize different target proteins. Thus, the structural plasticity of the chains plays an important role in controlling the binding events. Herein, paramagnetic NMR spectroscopy is employed to explore the conformational space sampled by linear diubiquitin, a minimal unit of linear polyubiquitin, in its free state. Rigorous analysis of the data suggests that, regarding the relative positions of the ubiquitin units, particular regions of conformational space are preferentially sampled by the molecule. By combining these results with further data collected for chargereversal derivatives of linear diubiquitin, structural insights into the factors underlying the binding events of linear diubiquitin are obtained.

Effects of radial electric field on the structures and dynamics of dust dipoles are studied by molecular dynamics simulations. The dipoles' configuration and mean distance to the system center are used to illustrate the structures of the whole system. It is shown that the dipole particles can arrange themselves into ring-like structures in the absence of external electric field, which can gradually transform to vortex, and then to radial arrangement with the increase of the strength of electric field. The trajectories, mean square displacement, and the mean speed in radial and tangential directions of dipoles are investigated to depict the effects of the radial electric filed on the collective motion of dust dipolar particles, which are closely associated with the growth of dust particle, especially for the formation of rod-like and some other complex fractal dust particles.

The coagulation and growth process of dust particles is investigated through laboratory experiment in a plasma system. A large number of dust particles with different sizes and shapes are formed. The growth process is characterized by the scattering laser intensity and fractal dimension. The comparisons of dust particles and scattering laser intensity obtained at different rf powers are presented. The three-dimensional distribution of dust particles is also given. These results provide an experimental basis for dust growth investigation.