A liquid lubricated head disk system is introduced. Subjected to high shear rate the rheology of the ultra thin film is different from that of the bulk continuum theory. The shear thinning effect is considered in setting up the mathematical model of the ultra thin film rheology. The Reynolds equation and the perturbation theory are employed to set up the static pressure distribution model and to deduce the dynamic pressure equation. The static and dynamic equations are solved by finite difference method. Based on the dynamic analysis the dynamic response of the slider is simulated and some valuable results are obtained about the static and dynamic characteristics of the liquid lubricated head disk systems.
The control method of highly redundant robot manipulators is introduced. A decentralized autonomous control scheme is used to guide the movement of robot manipulators so that the work done by manipulators is minimized. The method of computing pseudoinverse which needs too many complicated calculation can be avoided. Then the calculation and control of robots are simplified. At the same time system robustness/fault tolerance is achieved.
Experiments of poly（dT）20 electrophoresis throughα-hemolysin nanopores were performed to unveil the electrophoretic transport mechanism of DNA through nanopores in high concentration potassium chloride solution. It is found that there are two obvious current blockades induced by poly（dT）20 translocation and collision events. Both blockade currents increase linearly with the applied bias voltage. However, the normalized blockade currents are almost kept the same although variable bias voltages are applied. The collision time of poly（dT）20 in the luminal site of the pore remains constant for different voltages. The translocation speed of poly（dT）20through the nanopore decreases with the increase of bias voltage. It is because as the potential increases, the drag force on the homopolymer helps it to crumple into a cluster much easier due to the poor stacking of thymine residues compared with homopolymers consisting of other nucleotides. Molecular dynamics simulations further confirm the experimental results. Increasing the applied bias voltage can slowdown the translocation velocity of the flexible poly（dT）20, which favors increasing the precision of single molecule detection by using nanopores.
