174,263 research outputs found
Laboratory glassware rack for seismic safety
A rack for laboratory bottles and jars for chemicals and medicines has been designed to provide the maximum strength and security to the glassware in the event of a significant earthquake. The rack preferably is rectangular and may be made of a variety of chemically resistant materials including polypropylene, polycarbonate, and stainless steel. It comprises a first plurality of parallel vertical walls, and a second plurality of parallel vertical walls, perpendicular to the first. These intersecting vertical walls comprise a self-supporting structure without a bottom which sits on four legs. The top surface of the rack is formed by the top edges of all the vertical walls, which are not parallel but are skewed in three dimensions. These top edges form a grid matrix having a number of intersections of the vertical walls which define a number of rectangular compartments having varying widths and lengths and varying heights
The conductance of a multi-mode ballistic ring: beyond Landauer and Kubo
The Landauer conductance of a two terminal device equals to the number of
open modes in the weak scattering limit. What is the corresponding result if we
close the system into a ring? Is it still bounded by the number of open modes?
Or is it unbounded as in the semi-classical (Drude) analysis? It turns out that
the calculation of the mesoscopic conductance is similar to solving a
percolation problem. The "percolation" is in energy space rather than in real
space. The non-universal structures and the sparsity of the perturbation matrix
cannot be ignored.Comment: 7 pages, 8 figures, with the correct version of Figs.6-
The bulge luminosity functions in the MSX infrared bands
We use an inversion technique to derive the luminosity functions of the
Galactic bulge from point source counts extracted from the Midcourse Space
Experiment's Point Source Catalog (version 1.2).Comment: 5 pages, 2 figures, to be published in A&
Elevated waterproof access floor system and method of making the same
An elevated waterproof access floor system having subfloor channels or compartments for power lines, gas lines or the like is adapted such that it can be opened and subsequently resealed without destroying the waterproofing and without destroying its aesthetic appearance. A multiplicity of tiles are supported on a support grid, and a flooring sheet is supported on the tiles. Attachment means are provided to prevent lateral but not vertical movement of the flooring sheet with respect to the tiles so that the flooring sheet can be lifted off the tiles, but when the flooring sheet is supported on the tiles, no lateral slipping will occur. The flooring sheet is made of a heat resealable material, so that it can be cut away in sections, and the tiles therebelow lifted off, to provide access to subfloor compartments
A class of unambiguous state discrimination problems achievable by separable measurements but impossible by local operations and classical communication
We consider an infinite class of unambiguous quantum state discrimination
problems on multipartite systems, described by Hilbert space , of any
number of parties. Restricting consideration to measurements that act only on
, we find the optimal global measurement for each element of this
class, achieving the maximum possible success probability of in all
cases. This measurement turns out to be both separable and unique, and by our
recently discovered necessary condition for local quantum operations and
classical communication (LOCC), it is easily shown to be impossible by any
finite-round LOCC protocol. We also show that, quite generally, if the input
state is restricted to lie in , then any LOCC measurement on an
enlarged Hilbert space is effectively identical to an LOCC measurement on
. Therefore, our necessary condition for LOCC demonstrates directly
that a higher success probability is attainable for each of these problems
using general separable measurements as compared to that which is possible with
any finite-round LOCC protocol.Comment: Version 2 has new title along with an added discussion about using an
enlarged Hilbert space and why this is not helpfu
Thematic Knight\u27s Tour Quotes
Knight\u27s Tour Quotes (KTQs), also called Knight\u27s Tour Crypts, are a word puzzle enjoying a new vogue in the National Puzzlers\u27 League since David Silverman reintroduced them in 1973. Dmitri Borgmann presented some examples in Chesswords in the May 1974 Word Ways. A KTQ is a quote written out along a knight\u27s tour. It is a form, usually rectangular, with each square containing a single letter or punctuation mark. Stepping from letter to letter by knight\u27s moves (two squares horizontally or vertically, then one square perpendicular to that), visiting all letters once, one can spell out a message. To reduce the task from drudgery to pleasure, the starting letter is underlined and the word lengths and punctuation of the message are given
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