5,627 research outputs found
Regularizing effect and local existence for non-cutoff Boltzmann equation
The Boltzmann equation without Grad's angular cutoff assumption is believed
to have regularizing effect on the solution because of the non-integrable
angular singularity of the cross-section. However, even though so far this has
been justified satisfactorily for the spatially homogeneous Boltzmann equation,
it is still basically unsolved for the spatially inhomogeneous Boltzmann
equation. In this paper, by sharpening the coercivity and upper bound estimates
for the collision operator, establishing the hypo-ellipticity of the Boltzmann
operator based on a generalized version of the uncertainty principle, and
analyzing the commutators between the collision operator and some weighted
pseudo differential operators, we prove the regularizing effect in all (time,
space and velocity) variables on solutions when some mild regularity is imposed
on these solutions. For completeness, we also show that when the initial data
has this mild regularity and Maxwellian type decay in velocity variable, there
exists a unique local solution with the same regularity, so that this solution
enjoys the regularity for positive time
Magnetic ordering and fluctuation in kagome lattice antiferromagnets, Fe and Cr jarosites
Jarosite family compounds, KFe_3(OH)_6(SO_4)_2, (abbreviate Fe jarosite), and
KCr_3(OH)_6(SO_4)_2, (Cr jarosite), are typical examples of the Heisenberg
antiferromagnet on the kagome lattice and have been investigated by means of
magnetization and NMR experiments. The susceptibility of Cr jarosite deviates
from Curie-Weiss law due to the short-range spin correlation below about 150 K
and shows the magnetic transition at 4.2 K, while Fe jarosite has the
transition at 65 K. The susceptibility data fit well with the calculated one on
the high temperature expansion for the Heisenberg antiferromagnet on the kagome
lattice. The values of exchange interaction of Cr jarosite and Fe jarosite are
derived to be J_Cr = 4.9 K and J_Fe = 23 K, respectively. The 1H-NMR spectra of
Fe jarosite suggest that the ordered spin structure is the q = 0 type with
positive chirality of the 120 degrees configuration. The transition is caused
by a weak single-ion type anisotropy. The spin-lattice relaxation rate, 1/T_1,
of Fe jarosite in the ordered phase decreases sharply with lowering the
temperature and can be well explained by the two-magnon process of spin wave
with the anisotropy.Comment: REVTeX, 14 pages with 5 figures. Submitted to Canadian Journal of
Physic
The Rise of Gay Culture and Why Portland is Different
This paper serves as a short history of the gay movement in Portland, as well as the reasons why Portland’s movement was inherently dissimilar to the movements of other major cities. It begins by providing historical context on the movements of some of Americas biggest cities, focusing primarily on the 1969 events of the Stonewall Riots in New York, the election and assassination of Harvey Milk in San Francisco, and Seattle’s movement for the purpose of comparison. A brief history on homosexuality in Portland’s recent past follows, going on then to the influence of “Darcelle’s” for the growing gay movement in the late 1970s and 1980s. The election of Portland’s first gay mayor, Sam Adams, in 2008 concludes the paper
The Rise of Gay Culture and Why Portland is Different
This paper serves as a short history of the gay movement in Portland, as well as the reasons why Portland’s movement was inherently dissimilar to the movements of other major cities. It begins by providing historical context on the movements of some of Americas biggest cities, focusing primarily on the 1969 events of the Stonewall Riots in New York, the election and assassination of Harvey Milk in San Francisco, and Seattle’s movement for the purpose of comparison. A brief history on homosexuality in Portland’s recent past follows, going on then to the influence of “Darcelle’s” for the growing gay movement in the late 1970s and 1980s. The election of Portland’s first gay mayor, Sam Adams, in 2008 concludes the paper
Epigenomes in Cardiovascular Disease.
If unifying principles could be revealed for how the same genome encodes different eukaryotic cells and for how genetic variability and environmental input are integrated to impact cardiovascular health, grand challenges in basic cell biology and translational medicine may succumb to experimental dissection. A rich body of work in model systems has implicated chromatin-modifying enzymes, DNA methylation, noncoding RNAs, and other transcriptome-shaping factors in adult health and in the development, progression, and mitigation of cardiovascular disease. Meanwhile, deployment of epigenomic tools, powered by next-generation sequencing technologies in cardiovascular models and human populations, has enabled description of epigenomic landscapes underpinning cellular function in the cardiovascular system. This essay aims to unpack the conceptual framework in which epigenomes are studied and to stimulate discussion on how principles of chromatin function may inform investigations of cardiovascular disease and the development of new therapies
Bending and springback prediction method based on multi-scale finite element analyses for high bendability and low springback sheet generation
In this study, a sheet bendability and springback property evaluation technology through bending test simulations is newly developed using our multi-scale finite element analysis code, which is based on the crystallographic homogenization method
Mobilizing agro-biodiversity and social networks to cope with adverse effects of climate and social changes: experiences from Kitui, Kenya
Poster presented at 13th Congress of the International Society of Ethnobiology. Montpellier (France), 20-25 May 201
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