نتایج جستجو برای: ideal radius

تعداد نتایج: 133402  

1997
Jian Ping Lu

Elastic properties of carbon nanotubes and nanoropes are investigated using an empirical force-constant model. For single and multi-wall nanotubes the elastic moduli are shown to be insensitive to details of the structure such as the helicity, the tube radius and the number of layers. The tensile Young’s modulus and the torsion shear modulus calculated are comparable to that of the diamond, whi...

2011
Simon Rutishauser Irene Zanette Timm Weitkamp Tilman Donath Christian David

We report on the application of a two-dimensional hard x-ray grating interferometer to x-ray optics metrology. The interferometer is sensitive to refraction angles in two perpendicular directions with a precision of 10 nrad. It is used to observe the wavefront changes induced by a single parabolic beryllium focusing lens of large radius of curvature. The lens shape is reconstructed and its resi...

Journal: :Physical review letters 2014
S Le Pape L Divol L Berzak Hopkins A Mackinnon N B Meezan D Casey J Frenje H Herrmann J McNaney T Ma K Widmann A Pak G Grimm J Knauer R Petrasso A Zylstra H Rinderknecht M Rosenberg M Gatu-Johnson J D Kilkenny

A 200  μm radius hot spot at more than 2 keV temperature, 1  g/cm^{3} density has been achieved on the National Ignition Facility using a near vacuum hohlraum. The implosion exhibits ideal one-dimensional behavior and 99% laser-to-hohlraum coupling. The low opacity of the remaining shell at bang time allows for a measurement of the x-ray emission of the reflected central shock in a deuterium pl...

Journal: :Optics express 2010
Mona Mihailescu

A naturally-inspired phase-only diffractive optical element with a circular symmetry given by a quasi-periodic structure of the phyllotaxis type is presented in this paper. It is generated starting with the characteristic parametric equations which are optimal for the golden angle interval. For some ideal geometrical parameters, the diffracted intensity distribution in near-field has a central ...

2014
Emad Abu Osba Salah Al-Addasi Omar Abughneim

Let R be a commutative finite principal ideal ring with unity, and letG(R) be the simple graph consisting of nontrivial proper ideals of R as vertices such that two vertices I and J are adjacent if they have nonzero intersection. In this paper we continue the work done by Abu Osba. We calculate the radius, eccentricity, domination number, independence number, geodetic number, and the hull numbe...

Journal: :Adv. Operations Research 2009
Jafar Fathali Mehdi Zaferanieh Ahmad Nezakati

Let n weighted points be given in the plane R2. For each point a radius is given which is the expected ideal distance from this point to a new facility. We want to find the location of a new facility such that the sum of the weighted errors between the existing points and this new facility is minimized. This is in fact a nonconvex optimization problem. We show that the optimal solution lies in ...

2002
OGUZ C. DURUMERIC

Relatively extremal knots are the relative minima of the ropelength functional in the C1 topology. They are the relative maxima of the thickness (normal injectivity radius) functional on the set of curves of …xed length, and they include the ideal knots. We prove that a C1;1 relatively extremal knot in Rn either has constant maximal (generalized) curvature, or its thickness is equal to half of ...

H Seyyedhasani, M Sarvandi M.M Najafizadeh

Nanocomposites provide new properties and exploit unique synergism between materials. Polyvinylidene fluoride (PVDF) is an ideal piezoelectric matrix applicable in nanocomposites in a broad range of industries from oil and gas to electronics and automotive. And boron nitride nanotubes (BNNTs) show high mechanical, electrical and chemical properties. In this paper, the critical torsional load of...

2004
Frithjof Karsch

We present recent lattice results on QCD thermodynamics at nonvanishing baryon number density obtained from a 6th order Taylor expansion in the chemical potential. Results for bulk thermodynamic observables, in particular for fluctuations in the baryon number density, are found to be well described by a hadron resonance gas model at low temperature and an ideal quark gluon gas at high temperatu...

2008
Jan Geršl

The Bousso entropy bound is investigated in a static spherically symmetric spacetime filled with an ideal gas of massless bosons or fermions. Especially lightsheets generated by spheres are considered. A statistical description of the gas is given. Conditions under which the Bousso bound can be violated are discussed and it is shown that a possible violating region cannot be arbitrarily large a...

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