2,222 research outputs found
Exact soliton solution and inelastic two-soliton collision in spin chain driven by a time-dependent magnetic field
We investigate dynamics of exact N-soliton trains in spin chain driven by a
time-dependent magnetic field by means of an inverse scattering transformation.
The one-soliton solution indicates obviously the spin precession around the
magnetic field and periodic shape-variation induced by the time varying field
as well. In terms of the general soliton solutions N-soliton interaction and
particularly various two-soliton collisions are analyzed. The inelastic
collision by which we mean the soliton shape change before and after collision
appears generally due to the time varying field. We, moreover, show that
complete inelastic collisions can be achieved by adjusting spectrum and field
parameters. This may lead a potential technique of shape control of soliton.Comment: 5 pages, 5 figure
Quantum phase transition of condensed bosons in optical lattices
In this paper we study the superfluid-Mott-insulator phase transition of
ultracold dilute gas of bosonic atoms in an optical lattice by means of Green
function method and Bogliubov transformation as well. The superfluid-
Mott-insulator phase transition condition is determined by the energy-band
structure with an obvious interpretation of the transition mechanism. Moreover
the superfluid phase is explained explicitly from the energy spectrum derived
in terms of Bogliubov approach.Comment: 13 pages, 1 figure
The signal of in nucleon-antinucleon scattering
We study the production of at a nucleon-antinucleon scattering
experiment. Considering the PANDA experiment to be an ideal platform to explore
the production of the charmonium and charmonim-like states, we suggest the
forthcoming PANDA experiment to pay attention to the production of
.Comment: 6 pages, 15 figures. Published version in EPJ
Microheated substrates for patterning cells and controlling development
Here, we seek to control cellular development by devising a means through which cells can be subjected to a microheated environment in standard culture conditions. Numerous techniques have been devised for controlling cellular function and development via manipulation of surface environmental cues at the micro- and nanoscale. It is well understood that temperature plays a significant role in the rate of cellular activities, migratory behavior (thermotaxis), and in some cases, protein expression. Yet, the effects and possible utilization of micrometer-scale temperature fields in cell cultures have not been explored. Toward this end, two types of thermally isolated microheated substrates were designed and fabricated, one with standard backside etching beneath a dielectric film and another with a combination of surface and bulk micromachining and backside etching. The substrates were characterized with infrared microscopy, finite element modeling, scanning electron microscopy, stylus profilometry, and electrothermal calibrations. Neuron culture studies were conducted on these substrates to 1) examine the feasibility of using a microheated environment to achieve patterned cell growth and 2) selectively accelerate neural development on regions less than 100wide. Results show that attached neurons, grown on microheated regions set at 37, extended processes substantially faster than those incubated at 25on the same substrate. Further, unattached neurons were positioned precisely along the length of the heater filament (operating at 45) using free convection currents. These preliminary findings indicate that microheated substrates may be used to direct cellular development spatially in a practical manner.$hfillhbox[1414]
Enhancing commitment through work empowerment
Purpose – The research objectives are to investigate the perception of work empowerment of quantity
surveyors and to determine whether perceived work empowerment is an antecedent of commitment.
Design/methodology/approach – An exploratory study amongst quantity surveyors in four
different types of construction industry organisations in Hong Kong is conducted. Data are collected
by use of established questionnaires, yielding 136 valid responses.
Findings – Organisational commitment comprises dimensions of effectiveness and continuance. It is
found that when the perception of work empowerment increases, organisational commitment
increases accordingly. Work empowerment is related to affective commitment rather than continuance
commitment. Professional qualification and nationality are positively correlated with both dimensions
of organisational commitment. Chinese chartered quantity surveyors show more commitment to their
organisations. Generally, male QS shows less continuance commitment and the longer the QS has
worked for the organisation (particularly in consultancy firms), the less continuance commitment one
has.
Originality/value – The regression analysis supports the relationship of commitment and work
empowerment. Work empowerment enhances self-efficacy and, through motivation and commitment,
leads to increased performance and effectiveness
A failure study of the railway rail serviced for heavy cargo trains
AbstractIn this case study, a failed railway rail which was used for heavy cargo trains was investigated in order to find out its root cause. The macroscopic beach marks and microscopic fatigue striations were not observed by macro and microscopic observations. The chevron patterns were observed by macro observations. The crack origin was at the tip of chevron patterns. The fan-shaped patterns, cleavage step and the river patterns were observed at the crack origin, which demonstrated the feature of cleavage fracture. The metallurgical structures at the crack origin were pearlite and ferrite networks. The crack is supposed to be initiated from the weaker ferrite networks. Given all of that, the failed railway rail is considered to be caused by overload. It is of great importance to improve the welding technology, and control the load of train in order to prevent similar failure in future
corrections to polarized top decay into a charged Higgs
We calculate the radiative corrections to polarized top quark
decay into a charged Higgs boson and a massive bottom quark in two variants of
the two-Higgs-doublet model. The radiative corrections to the polarization
asymmetry of the decay may become as large as . We provide analytical
formulae for the unpolarized and polarized rates for and for . For our closed-form expressions for the unpolarized and
polarized rates become rather compact.Comment: 24 pages, 5 figures in the text, content modified, comments added,
appendices added, references updated, replaced with published versio
Nitrogen enrichment lowers Betula pendula green and yellow leaf stoichiometry irrespective of effects of elevated carbon dioxide.
Elevated carbon dioxide (C
Magnetoresistance of 2D and 3D Electron Gas in LaAlO3/SrTiO3 Heterostructures: Influence of Magnetic Ordering, Interface Scattering and Dimensionality
Magnetoresistance (MR) anisotropy in LaAlO3/SrTiO3 (LAO/STO) interfaces is
compared between samples prepared in high oxygen partial pressure (PO2) of 10-4
mbar exhibiting quasi-two-dimensional (quasi-2D) electron gas and low PO2 of
10-6 mbar exhibiting 3D conductivity. While MR of an order of magnitude larger
was observed in low PO2 samples compared to those of high PO2 samples, large MR
anisotropies were observed in both cases. The MR with the out-of-plane field is
always larger compared to the MR with in-plane field suggesting lower
dissipation of electrons from interface versus defect scattering. The quasi-2D
interfaces show a negative MR at low temperatures while the 3D interfaces show
positive MR for all temperatures. Furthermore, the angle relationship of MR
anisotropy for these two different cases and temperature dependence of in-plane
MR are also presented. Our study demonstrates that MR can be used to
distinguish the dimensionality of the charge transport and various (defect,
magnetic center, and interface boundary) scattering processes in this system.Comment: 14 pages, 5 figure
- …