Enhancing quantum entropy in vacuum-based quantum random number generator

Information-theoretically provable unique true random numbers, which cannot be correlated or controlled by an attacker, can be generated based on quantum measurement of vacuum state and universal-hashing randomness extraction. Quantum entropy in the measurements decides the quality and security of the random number generator. At the same time, it directly determine the extraction ratio of true randomness from the raw data, in other words, it affects quantum random numbers generating rate obviously. In this work, considering the effects of classical noise, the best way to enhance quantum entropy in the vacuum-based quantum random number generator is explored in the optimum dynamical analog-digital converter (ADC) range scenario. The influence of classical noise excursion, which may be intrinsic to a system or deliberately induced by an eavesdropper, on the quantum entropy is derived. We propose enhancing local oscillator intensity rather than electrical gain for noise-independent amplification of quadrature fluctuation of vacuum state. Abundant quantum entropy is extractable from the raw data even when classical noise excursion is large. Experimentally, an extraction ratio of true randomness of 85.3% is achieved by finite enhancement of the local oscillator power when classical noise excursions of the raw data is obvious.Comment: 12 pages,8 figure

Effects of Al addition on the structure and mechanical properties of Zn alloys

The noticeable improvement of hardness, elongation and yield stress in the cast zinc alloys was achieved using aluminium inoculation. Through varying the addition level of this eutectic-forming solute (aluminium), the mechanism of such property improvement of cast Zn alloys was investigated. The increase of hardness, elongation and yield stress was very sensitive to the aluminium content due to grain-refinement and solid-solution strengthening. Beyond the maximum solubility of aluminium in zinc, a three-dimensional eutectic network was developed to form a “eutectic-skeleton”, which produced further reinforcement in yield stress and elongation, but only marginal enhancement in hardness. These improved mechanical properties are found to be closely associated with significant microstructural refinement. The microstructural refinement, i.e. the columnar-to-equiaxed transition and the reduction in grain sizes, was mainly elucidated in terms of the Interdependence theory

Crystallography of phase transformation in the self-inclined InAs nanowires grown on GaAs(111)

During growth of InAs nanowires (NWs) on GaAs(111), the self-inclined InAs NWs were reproducibly observed. At the self-inclined interface, the h.c.p. InAs phase was transformed into another f.c.c. InAs phase. In order to investigate the crystallography of phase transformation, a recently-developed model, edge-to-edge matching (E2EM), was applied in such self-inclined NWs for crystallographic investigation. The orientation relationships (ORs), between f.c.c. InAs and h.c.p. InAs, were predicted using the E2EM model, which agrees well with experimental results. The results indicate the importance of crystallographic study in design and construction of nanostructured semiconductors with improved physical properties

Erratum: Corrigendum to “Crystallography of phase transformation in the self-inclined InAs nanowires grown on GaAs{111}” (Scripta Materialia (2016) 121 (79–83) (S1359646216301671) (10.1016/j.scriptamat.2016.04.039))

The authors regret “Au thin film” and caption of Fig. 1 were printed incorrectly; “Au thin film” should be deleted from Fig. 1. The correct version of Fig. 1 is shown below: 2. The sentence, “The ZB lattice parameters [35] are a\ua0=\ua00.40494\ua0nm with space group F4−3m. The WZ lattice parameters [35] are a\ua0=\ua00.2665\ua0nm and c\ua0=\ua00.4947\ua0nm with space groupP6/mmc.”, was also printed incorrectly. However, the calculation results are still right. The correct version is indicated as follows: “The ZB lattice parameters [35] are a\ua0=\ua00.606\ua0nm with space group F4−3m. The WZ lattice parameters [35] are a\ua0=\ua00.427\ua0nm, c\ua0=\ua00.703\ua0nm with space group P6mc.” The authors would like to apologise for any inconvenience caused

Spatiotemporal Change Patterns of Coastlines in Zhejiang Province, China, Over the Last Twenty-Five Years

Spatiotemporal analysis of coastline land utilization is important for strengthening coastline resource management and promoting sustainable development in coastal zones. In this study, basic spatiotemporal characteristics of coastline land utilization in Zhejiang Province, China, were analyzed using remote sensing (RS) and GIS techniques. For this case, Landsat Thematic Mapper and Operational Land Imager remote-sensing image data acquired from 1990 to 2015 were collected and processed. Several indices and metrics used for quantifying and analyzing the coastline utilization in Zhejiang Province were defined and calculated through processing remote sensing data and using GIS tools. They included the intensity index of coastline change, fractal dimension of the coastline, subjectivity of coastline utilization, and the integrated coastline utilization index. The analysis results demonstrated that (1) significant coastline changes took place in Zhejiang Province, and the coastline moved seaward, while the total coastline length decreased continuously; (2) the average fractal dimension of the coastlines was 1.0922, and it was relatively stable before 2000, but declined continuously after 2000, reduced to 1.086 in 2015; (3) the artificialization index of the coastlines kept rising; (4) there were single, binary, and other multi-land use types in different coastline sections in the study area; and (5) the coastline land use intensity increased continuously from 0.25 to 0.38, and the coastline in the Xiangshan Harbour had the highest land use intensity index, reaching 0.53 in 2015, throughout the study period, and in the study area