818 research outputs found
Experiments on the generation of long wavelength edge radiation along directions nearly coincident with the axis of a straight section of the "Pakhra" synchrotron
Generation of long wavelength edge radiation along directions nearly
coincident with the axes of straight sections of storage rings and synchrotrons
is discussed. The removal of destructive interference from the superimposed
edge radiation patterns of a straight section on the synchrotron "Pakhra" has
been observed experimentally.Comment: 8 pages, LaTeX, Presented to Proc. IV Int. Symp. Radiation from
Relativistic Electrons in periodic Structures, (RREPS'99) September 13-16,
1999, Lake Baikal, Russia (Proc. will be published in Nucl. Instr. Meth.).
Figures were replace
PrEP and HIV prevention decision-making among social network members of women who have experienced incarceration: a qualitative study
Incarceration and HIV are a syndemic for US women, yet very few women who have experienced incarceration use pre-exposure prophylaxis (PrEP) for HIV. We conducted semi-structured interviews with 32 participants recruited by women who have experienced incarceration from their social networks, informed by the modified social ecological model for PrEP. Emergent themes from the interviews included individual-level (low personal HIV risk assessment, personal responsibility for HIV prevention, and decisions in addiction versus recovery), network-level (influential sex partners and the importance of trust, supportive treatment peers, and high-risk but indifferent drug use networks), community-level (stigma, and mitigation of stigma in supportive substance use disorder treatment environments), and public policy-level (incarceration and PrEP cost and access) determinants. PrEP interventions for women who have experienced incarceration and their networks will need to incorporate contingency planning into HIV risk assessment, navigate complex network dynamics, and be situated in trusted contexts to address structural barriers
Applying ASP to UML model validation
We apply ASP to model validation in a CASE setting, where models are UML class diagrams and object diagrams are called \u201csnapshots\u201d. We present the design and implementation of MSG, a snapshot generator for UML models that employs DLV-Complex as a generator engine, the answer sets representing the legal snapshots
Cold Plasma Dispersion Relations in the Vicinity of a Schwarzschild Black Hole Horizon
We apply the ADM 3+1 formalism to derive the general relativistic
magnetohydrodynamic equations for cold plasma in spatially flat Schwarzschild
metric. Respective perturbed equations are linearized for non-magnetized and
magnetized plasmas both in non-rotating and rotating backgrounds. These are
then Fourier analyzed and the corresponding dispersion relations are obtained.
These relations are discussed for the existence of waves with positive angular
frequency in the region near the horizon. Our results support the fact that no
information can be extracted from the Schwarzschild black hole. It is concluded
that negative phase velocity propagates in the rotating background whether the
black hole is rotating or non-rotating.Comment: 27 pages, 11 figures accepted for publication in Gen. Relat. & Gravi
A Gravitational Aharonov-Bohm Effect, and its Connection to Parametric Oscillators and Gravitational Radiation
A thought experiment is proposed to demonstrate the existence of a
gravitational, vector Aharonov-Bohm effect. A connection is made between the
gravitational, vector Aharonov-Bohm effect and the principle of local gauge
invariance for nonrelativistic quantum matter interacting with weak
gravitational fields. The compensating vector fields that are necessitated by
this local gauge principle are shown to be incorporated by the DeWitt minimal
coupling rule. The nonrelativistic Hamiltonian for weak, time-independent
fields interacting with quantum matter is then extended to time-dependent
fields, and applied to problem of the interaction of radiation with
macroscopically coherent quantum systems, including the problem of
gravitational radiation interacting with superconductors. But first we examine
the interaction of EM radiation with superconductors in a parametric oscillator
consisting of a superconducting wire placed at the center of a high Q
superconducting cavity driven by pump microwaves. We find that the threshold
for parametric oscillation for EM microwave generation is much lower for the
separated configuration than the unseparated one, which then leads to an
observable dynamical Casimir effect. We speculate that a separated parametric
oscillator for generating coherent GR microwaves could also be built.Comment: 25 pages, 5 figures, YA80 conference (Chapman University, 2012
Tritium Beta Decay, Neutrino Mass Matrices and Interactions Beyond the Standard Model
The interference of charge-changing interactions, weaker than the V-A
Standard Model (SM) interaction and having a different Lorentz structure, with
that SM interaction, can, in principle, produce effects near the end point of
the Tritium beta decay spectrum which are of a different character from those
produced by the purely kinematic effect of neutrino mass expected in the
simplest extension of the SM. We show that the existence of more than one mass
eigenstate can lead to interference effects at the end point that are stronger
than those occurring over the entire spectrum. We discuss these effects both
for the special case of Dirac neutrinos and the more general case of Majorana
neutrinos and show that, for the present precision of the experiments, one
formula should suffice to express the interference effects in all cases.
Implications for "sterile" neutrinos are noted.Comment: 32 pages, LaTeX, 6 figures, PostScript; full discussion and changes
in notation from Phys. Lett. B440 (1998) 89, nucl-th/9807057; submitted to
Phys. Rev.
QCD condensates and hadron parameters in nuclear matter: self-consistent treatment, sum rules and all that
We review various approaches to the calculation of QCD condensates and of the
nucleon characteristics in nuclear matter. We show the importance of their
self-consistent treatment. The first steps in such treatment appeared to be
very instructive. It is shown that the alleged pion condensation anyway can not
take place earlier than the restoration of the chiral symmetry. We demonstrate
how the finite density QCD sum rules for nucleons work and advocate their
possible role in providing an additional bridge between the condensate and
hadron physics.Comment: 67 pages, LaTeX, 15 figures, epsfig.sty; to be published in "Progress
in Particle and Nuclear Physics", vol.47, is.
On the Nature of the party statute
国内学者对于“党内法规”的研究相对完善,在不同角度分别给出了不同的定义,综合的来看我们可以将“党内法规”这一个宏观概念诠释为包含了法律、纪律、行政规范以及制度建设等多个方面。在本文的研究中我们应该严谨地来探讨“党内法规”的本意,并从中找到我们是在什么意义上或什么层面上使用这个概念。这样便于我们有效地进行有关的科学探讨。 在当前理论研究中,学术界对于“党内法规”这个提法是有一定争议的。有学者认为,“由于‘党内法规’这一提法不能准确地将党的规章制度与国家法律法规相区别,建议用‘党的纪律’代替‘党内法规’的相关定义,此种提法是相对准确的。同时,部分研究人员从法学的角度给出了不同的定义,其认为法规与..." Party regulations," the word as a concept , there are many inherent meanings , including party discipline , party system , the party's legal . From the party's history, " the party regulations," often from a different angle or significance used up . As an academic discussion , we should rigorously to explore the "inner regulations," the intention , and find meaning in what we are or what level t...学位:法律硕士院系专业:法学院法律系_法律硕士(JM)学号:X200812014
Dynamical stability of infinite homogeneous self-gravitating systems: application of the Nyquist method
We complete classical investigations concerning the dynamical stability of an
infinite homogeneous gaseous medium described by the Euler-Poisson system or an
infinite homogeneous stellar system described by the Vlasov-Poisson system
(Jeans problem). To determine the stability of an infinite homogeneous stellar
system with respect to a perturbation of wavenumber k, we apply the Nyquist
method. We first consider the case of single-humped distributions and show
that, for infinite homogeneous systems, the onset of instability is the same in
a stellar system and in the corresponding barotropic gas, contrary to the case
of inhomogeneous systems. We show that this result is true for any symmetric
single-humped velocity distribution, not only for the Maxwellian. If we
specialize on isothermal and polytropic distributions, analytical expressions
for the growth rate, damping rate and pulsation period of the perturbation can
be given. Then, we consider the Vlasov stability of symmetric and asymmetric
double-humped distributions (two-stream stellar systems) and determine the
stability diagrams depending on the degree of asymmetry. We compare these
results with the Euler stability of two self-gravitating gaseous streams.
Finally, we determine the corresponding stability diagrams in the case of
plasmas and compare the results with self-gravitating systems
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