302,658 research outputs found

### Dynamic Model and Phase Transitions for Liquid Helium

This article presents a phenomenological dynamic phase transition theory --
modeling and analysis -- for superfluids. As we know, although the
time-dependent Ginzburg-Landau model has been successfully used in
superconductivity, and the classical Ginzburg-Landau free energy is still
poorly applicable to liquid helium in a quantitative sense. The study in this
article is based on 1) a new dynamic classification scheme of phase
transitions, 2) new time-dependent Ginzburg-Landau models for general
equilibrium transitions, and 3) the general dynamic transition theory. The
results in this article predict the existence of a unstable region H, where
both solid and liquid He II states appear randomly depending on fluctuations
and the existence of a switch point M on the lambda-curve, where the
transitions changes types

### Utility of a Special Second Scalar Doublet

This Brief Review deals with the recent resurgence of interest in adding a
second scalar doublet (eta^+,eta^0) to the Standard Model of particle
interactions. In most studies, it is taken for granted that eta^0 should have a
nonzero vacuum expectation value, even if it may be very small. What if there
is an exactly conserved symmetry which ensures =0? The phenomenological
ramifications of this idea include dark matter, radiative neutrino mass,
leptogenesis, and grand unification.Comment: 9 pages, 1 figur

### Supersymmetric U(1) Gauge Realization of the Dark Scalar Doublet Model of Radiative Neutrino Mass

Adding a second scalar doublet (eta^+,eta^0) and three neutral singlet
fermions N_{1,2,3} to the Standard Model of particle interactions with a new
Z_2 symmetry, it has been shown that Re(eta^0) or Im(eta^0) is a good
dark-matter candidate and seesaw neutrino masses are generated radiatively. A
supersymmetric U(1) gauge extension of this new idea is proposed, which
enforces the usual R parity of the Minimal Supersymmetric Standard Model, and
allows this new Z_2 symmetry to emerge as a discrete remnant.Comment: 8 pages, 3 figure

### A Remark on Soliton Equation of Mean Curvature Flow

In this short note, we consider self-similar immersions $F: \mathbb{R}^n \to
\mathbb{R}^{n+k}$ of the Graphic Mean Curvature Flow of higher co-dimension. We
show that the following is true: Let $F(x) = (x,f(x)), x \in \mathbb{R}^{n}$ be
a graph solution to the soliton equation $\bar{H}(x) + F^{\bot}(x) = 0.$
Assume $\sup_{\mathbb{R}^{n}}|Df(x)| \le C_{0} < + \infty$. Then there exists a
unique smooth function $f_{\infty}: \mathbb{R}^{n}\to \mathbb{R}^k$ such that
$f_{\infty}(x) = \lim_{\lambda \to \infty}f_{\lambda}(x)$ and $f_{\infty}(r x)=r f_{\infty}(x)$ for any real number $r\not= 0$, where $f_{\lambda}(x) = \lambda^{-1}f(\lambda x).$Comment: 6 page

### Muscle Fatigue Analysis Using OpenSim

In this research, attempts are made to conduct concrete muscle fatigue
analysis of arbitrary motions on OpenSim, a digital human modeling platform. A
plug-in is written on the base of a muscle fatigue model, which makes it
possible to calculate the decline of force-output capability of each muscle
along time. The plug-in is tested on a three-dimensional, 29 degree-of-freedom
human model. Motion data is obtained by motion capturing during an arbitrary
running at a speed of 3.96 m/s. Ten muscles are selected for concrete analysis.
As a result, the force-output capability of these muscles reduced to 60%-70%
after 10 minutes' running, on a general basis. Erector spinae, which loses
39.2% of its maximal capability, is found to be more fatigue-exposed than the
others. The influence of subject attributes (fatigability) is evaluated and
discussed

### Osgood-Hartogs type properties of power series and smooth functions

We study the convergence of a formal power series of two variables if its
restrictions on curves belonging to a certain family are convergent. Also
analyticity of a given $C^\infty$ function $f$ is proved when the restriction
of $f$ on analytic curves belonging to some family is analytic. Our results
generalize two known statements: a theorem of P. Lelong and the Bochnak-Siciak
Theorem. The questions we study fall into the category of "Osgood-Hartogs-type"
problems.Comment: 13 page

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