The ground state and persistent current of mesoscopic Aharonov-Bohm ring embedded with a quantum dot

An interacting quantum dot inserted in an Aharonov-Bohm ring is investigated.The explicit expression of the ground-state energy and the persistent current of the system are obtained by a second-order variational perturbation approximation method.The numerical results of the Kondo temperature and the ground-state persistent current of the system are also given under the condition that the Coulomb repulsion is infinite.</jats:p

Influential factors and analysis of detecting buried trash in scattering media

Detection of buried trash in scattering media is a very important research project. Detection efficiency is influenced by several imaging parameters, such as incident light intensity, trash buried depth, medium refractivity, medium scattering coefficient and medium anisotropic factor. Firstly, current Monte Carlo algorithm is revised. Secondly, influential laws of those parameters are researched by simulating a great number of photons propagating in a scattering medium. The results indicate that light intensity, trash buried depth and medium refractivity greatly affect both reflection and transmission imaging results; and their influential laws are similar. Detection efficiency of reflection imaging can be improved by increasing light intensity, reducing trash buried depth or medium refractivity. Detection efficiency of transmission imaging can be improved by increasing light intensity, reducing medium refractivity and scattering coefficient, or increasing anisotropic factor. These conclusions have universal significance of guidance in the detection of buried trash in scattering media.</jats:p

Network model with synchronously increasing nodes and edges based on Web 2.0

We investigate the growing process and topological features of Web 2.0 networks. By analyzing the network’s degree distribution, average degree and time evolution of the node degree of an actual blog on portal website, we found these properties are different from those of the former scale-free network models. According to the growth characteristics of actual networks, we put forward a new type of network with synchronously increasing nodes and edges, including construction algorithms of randomly linking and connection between close neighbours. The simulation results show that the networks generated from our model have power-law degree distribution in case of absence of the preferential attachment process, and the clustering coefficient increases and the connectivity correlations are assortative.</jats:p