The driven translocation kinetics of a single strand polynucleotide chain through a nanopore is studied using off-lattice Monte Carlo simulations, by which the authors demonstrate a novel method in controlling the driven polymer transport through a nanopore by a rotating electric field. The recorded time series of blockade current from the driven polynucleotide transport are used to determine the sequence of polynucleotides by implementing a modified Monte Carlo algorithm, in which the energy landscape paving technique is incorporated to avoid trapping at deep local minima. It is found that only six-time series of block current are required to completely determine the polynucleotide sequence if the average missing rate (AMR) of current signals in these time series is smaller than 20%. For those time series with AMR greater than 20%, the error rate in sequencing an unknown polynucleotide decreases rapidly by increasing the number of time series. To find the most appropriate experimental conditions, the authors have investigated the dependence of AMR of current signals and qualified rate of measured time series of blockade current on various controllable experimental variables.

Using atomic force microscopy and scanning electron microscopy (SEM), we investigate the correlations between the microstructural defects and the electrical characteristics of the bicrystal grain-boundary Josephson junctions and dc superconducting quantum inference devices (SQUIDs). The structural defects are shown to correlate qualitatively with the characteristics of grain-boundary Josephson junctions patterned on the YBa2Cu3O7−x film. SEM images show that these defects grown on the grain boundary were a few submicron depth of the groove. The low flux noise characteristics were observed when the groove depth was smaller than 18nm in the junctions of the SQUID. The existence of these defects is expected to affect the supercurrent and the motion of the magnetic flux in the films, which dominate the excess noise in the SQUID with bicrystal junctions.

No abstract

Organic small molecule and polymer materials are being considered as solar cell material in place of silicon wafer. Organic solar cells are now a popular subject in international research. This study uses ZnPc and C 60 as respectively the donor material and acceptor material of Organic Solar Cells (OSC) and examines the effects of different blocking layers and structures (P-N junction and P-IN structure) on open-circuit voltage (V OC), short-circuit current (I SC), fill factor (FF) and efficiency of solar cell. It is found under the same thickness of 15nm, the short-circuit current generated by the BCP and BAlq 3 blocking layers is respectively 1.36 and 1.19 mA/cm 2. This is because the BCP has higher energy gap and Highest Occupied Molecular Orbital (HOMO) than BAlq 3 , which enables BCP to block excitons and holes better. When the P-IN structure is ZnPc(30 nm)/C 60 (40 nm) and ZnPc(30 nm)/ZnPc:C 60 (20 nm)/C 60 (40 nm), the short-circuit current produced could be increased to 2.67 mA/cm 2 respectively. This is because the intrinsic layer increases the contact area of P-N junction, enabling more excitons to dissociate into free charges.

No abstract