4,699 research outputs found
The Chinese New Middle Class and Green NGOs in South China: Vanguards of Guanxi (Connections)-Seeking, Laggards in Promoting Social Causes?
By examining the emerging Chinese new middle class as well as green non-governmental organisations, this study finds that while the emergence of the Chinese new middle class facilitates the growth of green NGOs, the Chinese new class is not activists or agitators working against the government. Based on in-depth interviews with leaders of green NGOs founded by the Chinese new middle class in Guangdong province, this research examines why green NGOs do not call for or advocate environmental protection It concludes that contrary to conventional wisdom, the Chinese new middle class is a vanguard of guanxi (connections)-seeking, but a laggard in promoting environmental protection and civil-society activism. Green NGOs are principally used as a tool to cultivate social capital in the form of guanxi in order to promote personal material interests
Hydrodynamic Description of Granular Convection
We present a hydrodynamic model that captures the essence of granular
dynamics in a vibrating bed. We carry out the linear stability analysis and
uncover the instability mechanism that leads to the appearance of the
convective rolls via a supercritical bifurcation of a bouncing solution. We
also explicitly determine the onset of convection as a function of control
parameters and confirm our picture by numerical simulations of the continuum
equations.Comment: 14 pages, RevTex 11pages + 3 pages figures (Type csh
Azimuthal anisotropy: transition from hydrodynamic flow to jet suppression
Measured 2nd and 4th azimuthal anisotropy coefficients v_{2,4}(N_{part}),
p_T) are scaled with the initial eccentricity \varepsilon_{2,4}(N_{part}) of
the collision zone and studied as a function of the number of participants
N_{part} and the transverse momenta p_T. Scaling violations are observed for
p_T \alt 3 GeV/c, consistent with a dependence of viscous corrections
and a linear increase of the relaxation time with . These empirical
viscous corrections to flow and the thermal distribution function at freeze-out
constrain estimates of the specific viscosity and the freeze-out temperature
for two different models for the initial collision geometry. The apparent
viscous corrections exhibit a sharp maximum for p_T \agt 3 GeV/c, suggesting
a breakdown of the hydrodynamic ansatz and the onset of a change from
flow-driven to suppression-driven anisotropy.Comment: 5 pages, 4 figs; submitted for publicatio
Topology in Physics - A Perspective
This article, written in honor of Fritz Rohrlich, briefly surveys the role of
topology in physics.Comment: 16pp, 2 figures included (encapsulated postscript
Unparticle physics in top pair signals at the LHC and ILC
We study the effects of unparticle physics in the pair productions of top
quarks at the LHC and ILC. By considering vector, tensor and scalar unparticle
operators, as appropriate, we compute the total cross sections for pair
production processes depending on scale dimension d_{\U}. We find that the
existence of unparticles would lead to measurable enhancements on the SM
predictions at the LHC. In the case of ILC this may become two orders of
magnitude larger than that of SM, for smaller values of d_\U, a very striking
signal for unparticles.Comment: 19 pages, 9 figures, analysis for ILC has been adde
Fluctuations of the number of participants and binary collisions in AA interactions at fixed centrality in the Glauber approach
In the framework of the classical Glauber approach, the analytical
expressions for the variance of the number of wounded nucleons and binary
collisions in AA interactions at a given centrality are presented. Along with
the optical approximation term, they contain additional contact terms arising
only in the case of nucleus-nucleus collisions. The magnitude of the additional
contributions, e.g., for PbPb collisions at SPS energies, is larger than the
contribution of the optical approximation at some values of the impact
parameter. The sum of the additional contributions is in good agreement with
the results of independent Monte Carlo simulations of this process. Due to
these additional terms, the variance of the total number of participants for
peripheral PbPb collisions and the variance of the number of collisions at all
values of the impact parameter exceed several multiples of the Poisson
variances. The correlator between the numbers of participants in colliding
nuclei at fixed centrality is also analytically calculated.Comment: updated version; as published by Phys. Rev.
Coulomb effects on growth of instabilities in asymmetric nuclear matter
We study the effects of the Coulomb interaction on the growth of unstable
modes in asymmetric nuclear matter. In order to compare with previous
calculations we use a semiclassical approach based on the linearized Vlasov
equation. Moreover, a quantum calculation is performed within the R.P.A.. The
Coulomb effects are a slowing down of the growth and the occurrence of a
minimal wave vector for the onset of the instabilities. The quantum corrections
cause a further decrease of the growth rates.Comment: 10 pages, revtex, 4 ps figures, to appear in Phys. Rev. C e-mail:
[email protected], [email protected]
Traffic Equations and Granular Convection
We investigate both numerically and analytically the convective instability
of granular materials by two dimensional traffic equations. In the absence of
vibrations the traffic equations assume two distinctive classes of fixed bed
solutions with either a spatially uniform or nonuniform density profile. The
former one exists only when the function V(\rho) that monitors the relaxation
of grains assumes a cut off at the closed packed density, \rho_c, with
V(\rho_c)=0, while the latter one exists for any form of V. Since there is
little difference between the uniform and nonuniform solution deep inside the
bed, the convective instability of the bulk may be studied by focusing on the
stability of the uniform solution. In the presence of vibrations, we find that
the uniform solution bifurcates into a bouncing solution, which then undergoes
a supercritical bifurcation to the convective instability. We determine the
onset of convection as a function of control parameters and confirm this
picture by solving the traffic equations numerically, which reveals bouncing
solutions, two convective rolls, and four convective rolls. Further, convective
patterns change as the aspect ratio changes: in a vertically long container,
the rolls move toward the surface, and in a horizontally long container, the
rolls move toward the walls. We compare these results with those reported
previously with a different continuum model by Hayakawa, Yue and Hong[Phys.
Rev. Lett. 75,2328, 1995]. Finally, we also present a derivation of the traffic
equations from Enskoq equation.Comment: 34 pages, 10 figure
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