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The current-voltage characteristics of a silicon nanochain is investigated. The nanochain is viewed as a superlattice structure of quantum dots (QDs), where silicon cores in a chain act as QDs while silicon dioxides covering the cores act as potential barriers. It is found that the whole nanochain structure can display the negative differential conductance (NDC) feature as the tunneling current through each barrier has the NDC property individually. Importantly, large peak-to-valley ratios of the current are observed and tunable by the number of QDs involved. This feature will be useful in device design. [ABSTRACT FROM AUTHOR]

We present a basis selection method for truncated shell-model calculations. In this method, the correlated basis is constructed with the eigenvectors of the Hamiltonian that is diagonalized in each partition of the shell model. A truncation scheme is established by naturally taking the low-lying correlated-basis vectors in different partitions, which is equivalent to the j j -coupling scheme of the shell model when all the correlated-basis vectors are considered. The results are compared with standard shell-model calculations. The convergence properties of the correlated-basis method are discussed. [ABSTRACT FROM AUTHOR]

The recombination kinetics of Te isoelectronic centers in ZnS1-xTex (0.0065≤x≤0.85) alloys is studied by time-resolved photoluminescence (TRPL) at low temperature. The measured radiative recombination lifetimes of different Te bound exciton states are quite different, varying from a few nanoseconds to tens of nanosecond. As the bound exciton state evolves from a single Te impurity (Te1) to larger Te clusters (Ten,n=2,3,4), the recombination lifetime increases. It reaches maximum (∼40 ns) for the Te4 bound states at x=0.155. The increase of the exciton lifetime is attributed to the increasing exciton localization effect caused by larger localization potential. In the large Te composition range (x>0.155), the exciton recombination lifetime decreases monotonically with Te composition. It is mainly due to the hybridization between the Te localized states and the host valence band states. The composition dependences of the exciton binding energy and the photoluminescence (PL) line width show the similar tendency that further support the localization picture obtained from the TRPL measurement. [ABSTRACT FROM AUTHOR]

Collisions involving 112Sn and 124Sn nuclei have been calculated with the ImQMD transport model in order to place constraints on the density dependences of the nuclear symmetry energy. Consistent constraints on the symmetry energy at sub-saturation density have been obtained by comparing these transport calculations to measurements of isospin diffusion and to the ratios of neutron and proton spectra. New isospin diffusion results from E/A = 35 MeV are also presented. [ABSTRACT FROM AUTHOR]

HIRFL is an accelerator complex consisting of 3 accelerators, 2 radioactive beams lines, 1 storage rings and a number of experimental setups. The research activities at HIRFL cover the fields of radio-biology, material science, atomic physics, and nuclear physics. This report mainly concentrates on the experiments of nuclear physics with the existing and planned experimental setups such as SHANS, RIBLL1, ETF, CSRe, PISA and HPLUS at HIRFL. [ABSTRACT FROM AUTHOR]

Abstract: The ATLAS barrel toroid warm structure supports the barrel toroid and the muon detectors. The warm structure is about 26 meters long with an outer diameter of 20 meters. In order to ensure the physics performance of the muon detectors, the deformation of the warm structure is minimised during the design phase. The barrel toroid assembly has been carried out in the cavern of the ATLAS experiment since end of 2004. In September 2005, the warm structure has been completely released. The release has been followed-up in real time using optical alignment sensors. Good agreement has been found within 1mm, between the alignment system measurement, the geometer survey and the predicted values according to the finite element analyses results. [Copyright &y& Elsevier]

The longitudinal momentum (p//) distributions of fragments after one-proton removal and reaction cross sections (σR) for several N = 10 isotones at intermediate energy (~ 70A MeV) have been measured simultaneously at the RIken Projectile fragment Separator (RIPS). p// was measured using a direct time-of-flight (TOF) technique, while σR was determined using a transmission method. An enhanced σR is observed for 23Al comparing with its neighbors. The p// distribution for 22Mg fragments from 23Al one-proton removal reaction has been obtained for the first time. The experimental data are discussed within a Few Body Glauber (FBG) framework. Analysis of p// indicates a dominant d-wave component in the ground state of 23Al. This agrees with recent experimental results. We also suggest the possibility of an enlarged 22Mg core for proton-rich nucleus 23Al. [ABSTRACT FROM AUTHOR]