81,233 research outputs found
Skyrme-force time-dependent Hartree-Fock calculations with axial symmetry
We discuss axially symmetric time-dependent Hartree-Fock calculations using a finite-range modification of the Skyrme energy functional. The finite-difference forms of the coordinate-space time-dependent Hartree-Fock equations, the method of time evolution, and other numerical aspects are presented. Detailed results for (^84)Kr-induced deep-inelastic collisions with (^208)Pb at E_(lab) = 494 MeV and with (^209)Bi at E_(lab) = 600 MeV and 714 MeV are compared with experiment.
[NUCLEAR REACTIONS (^84)Kr + (^208)Pb at E_lab = 494 MeV and (^84)Kr + (^209)Bi at E_1ab=600 and 714 MeV, in the time-dependent Hartree-Fock approximation. Strongy
damped collisions. Details of Skyrme force calculations with axial symmetry.
Spectroscopy from Lattice QCD
We present first results for spectroscopy using Lattice
Non-Relativistic QCD (NRQCD). For the NRQCD action the leading order
spin-dependent and next to leading order spin-independent interactions have
been included with tadpole-improved coefficients. We use multi-exponential fits
to multiple correlation functions to extract ground and excited states and
give accurate values for the state hyperfine splitting and the P state
() fine structure, including the effects of mixing.Comment: 12 pages uuencoded latex file + 1 postscript figur
Recovering the lost Moravian history of William Blake's family
This paper seeks to amend and extend Keri Davies’s essay on Blake’s mother published in Blake/An Illustrated Quarterly in 1999. There, he established that Blake’s mother Catherine’s true maiden name was Wright, and that Thomas Armitage, her first husband, was born in Royston, Yorkshire in 1722, the son of Richard Armitage of Cudworth. Davies also produced evidence that contradicted E.P. Thompson’s Muggletonian hypothesis, and speculated upon the identity of Blake’s maternal grandparents. We now link Blake’s mother to a very different religious community, providing further evidence about her first marriage, and correcting the assumptions Davies made in identifying Blake’s grandparents. These latest discoveries about Blake’s mother disclose her place of birth (Walkeringham, Nottinghamshire), the names of her parents and siblings, and her association with the Moravian sect. Documentary and autographic records in the archive of the distinctive and exceptional eighteenth-century Moravian church, some dating from many years before the poet was born, are a vivid indicator of how much of our thinking about Blake’s life and early influences might need to be revised and rewritten in the future
Probation training: the experience of teachers and learners
Original article can be found at: http://www.informaworld.com/ Copyright Informa / Taylor and Francis GroupQualifying training in probation is under review and likely to be substantially changed. This article draws on a small scale study of current training arrangements designed to explore the views of trainee probation officers, practice development assessors and university tutors regarding which elements of the current Diploma in Probation Studies framework most support learning. Their comments focus on the organisational ownership of training, time and learning, the teacher-learner relationship, teaching methods and equality of access. It is argued that probation training is best supported by a series of linked qualifications across grades, integrating practice-based and academic learning delivered through a 'blended learning' model.Peer reviewe
Autonomous Locomotion Mode Transition Simulation of a Track-legged Quadruped Robot Step Negotiation
Multi-modal locomotion (e.g. terrestrial, aerial, and aquatic) is gaining
increasing interest in robotics research as it improves the robots
environmental adaptability, locomotion versatility, and operational
flexibility. Within the terrestrial multiple locomotion robots, the advantage
of hybrid robots stems from their multiple (two or more) locomotion modes,
among which robots can select from depending on the encountering terrain
conditions. However, there are many challenges in improving the autonomy of the
locomotion mode transition between their multiple locomotion modes. This work
proposed a method to realize an autonomous locomotion mode transition of a
track-legged quadruped robot steps negotiation. The autonomy of the
decision-making process was realized by the proposed criterion to comparing
energy performances of the rolling and walking locomotion modes. Two climbing
gaits were proposed to achieve smooth steps negotiation behaviours for energy
evaluation purposes. Simulations showed autonomous locomotion mode transitions
were realized for negotiations of steps with different height. The proposed
method is generic enough to be utilized to other hybrid robots after some
pre-studies of their locomotion energy performances
Construction and Calibration of a Streaked Optical Spectrometer for Shock Temperature
Here we describe the implementation and calibration of a streaked visible
spectrometer (SVS) for optical pyrometry and emission/absorption spectroscopy
on light gas gun platforms in the UC Davis Shock Compression Laboratory. The
diagnostic consists of an optical streak camera coupled to a spectrometer to
provide temporally and spectrally-resolved records of visible emission from
dynamically-compressed materials. Fiber optic coupling to the sample enables a
small diagnostic footprint on the target face and flexibility of operation on
multiple launch systems without the need for open optics. We present the
details of calibration (time, wavelength and spectral radiance) for absolute
temperature determination and present benchmark measurements of system
performance.Comment: 6 pages, 3 figures Davies, E., et al. (accepted). In J. Lane, T.
Germann, and M. Armstrong (Eds.), 21st Biennial APS Conference on Shock
Compression of Condensed Matter (SCCM19). AIP Publishin
A simulated investigation on the machining instability and dynamic surface generation
In this paper, the authors propose the generic concept of machining instability based on the analysis of all kinds of machining instable behaviors and their features. The investigation covers all aspects of the machining process, including the machine tool structural response, cutting process variables, tooling geometry and workpiece material property in a full dynamic scenario. The paper presents a novel approach for coping with the sophisticated machining instability and enabling better understanding of its effect on the surface generation through a combination of the numerical method with the characteristic equations and using block diagrams/functions to represent implicit equations and nonlinear factors. It therefore avoids the lengthy algebraic manipulations in deriving the outcome and the solution scheme is thus simple, robust and intuitive. Several machining case studies and their simulation results demonstrate the proposed approach is feasible for shop floor CNC machining optimisation in particular. The results also indicate the proposed approach is useful to monitor the machining instability and surface topography and to be potentially applied in adaptive control of the instability in real time
- …
