1,121 research outputs found
First Documented Record of \u3ci\u3eOarisma Powesheik\u3c/i\u3e (Lepidoptera: Hesperiidae) in Canada
During a brief survey of the prairie areas near Vita, Manitoba, July 1985, Oarisma powesheik Parker was found to be abundant, although often local. Specimens collected constitute the first documented record for the species in Canada
On the Equivalence Problem for Toric Contact Structures on S^3-bundles over S^2$
We study the contact equivalence problem for toric contact structures on
-bundles over . That is, given two toric contact structures, one can
ask the question: when are they equivalent as contact structures while
inequivalent as toric contact structures? In general this appears to be a
difficult problem. To find inequivalent toric contact structures that are
contact equivalent, we show that the corresponding 3-tori belong to distinct
conjugacy classes in the contactomorphism group. To show that two toric contact
structures with the same first Chern class are contact inequivalent, we use
Morse-Bott contact homology. We treat a subclass of contact structures which
include the Sasaki-Einstein contact structures studied by physicists.
In this subcase we give a complete solution to the contact equivalence problem
by showing that and are inequivalent as contact structures
if and only if .Comment: 61 page
Ground state of the Kagome-like S=1/2 antiferromagnet, Volborthite Cu3V2O7(OH)2.2H2O
Volborthite compound is one of the very few realizations of S=1/2 quantum
spins on a highly frustrated kagome-like lattice. Low-T SQUID measurements
reveal a broad magnetic transition below 2K which is further confirmed by a
peak in the 51V nuclear spin relaxation rate (1/T1) at 1.4K0.2K. Through
51V NMR, the ground state (GS) appears to be a mixture of different spin
configurations, among which 20% correspond to a well defined short range order,
possibly of the type. While the freezing involve all
the Cu spins, only 40% of the copper moment is actually frozen which
suggests that quantum fluctuations strongly renormalize the GS.Comment: 4 pages, 4 figures, to appear in PR
Assay, Purification, and Partial Characterization of Choline Monooxygenase from Spinach
Studie der optimalen Zone der unabhängigen Parameter eines Orgel-Reaktors in einem 250 MWe-Kraftwerk. EUR 466. = Study of the optimal zone of the independent parameters of an organ reactor in a 250 MWe power plant. EUR 466.
NanoWalker: a fully autonomous highly integrated miniature robot for nanoscale measurements
The aim of this project is to develop the smallest and most sophisticated wireless fully autonomous instrumented robot capable of subatomic movements. The robot named 'NanoWalker' should bring a new paradigm in the way instruments are built while providing a sophisticated platform for a new range of applications. The project involves primarily the investigation of a new legged locomotion based on piezo-actuators with advanced micro-assembly techniques applied to complex embedded electronic systems; the development of new miniature instruments, micro-manipulators, integrated behavior for controlling, searching and scanning at the atomic scale; and the development of a subatomic navigation system. Besides all the new technologies and techniques that we intend to develop and which will be applicable to many areas and systems, the NanoWalker should provide a suitable yet more flexible and powerful platform compared to traditional macro-scaled instruments. It is anticipated that this new form of highly integrated autonomous microsystem will be used as the main building block for a new generation of measurement and inspection systems. In this paper, the main components of the NanoWalker are briefly described.Seaver Institut
Vesignieite BaCu3V2O8(OH)2 as a Candidate Spin-1/2 Kagome Antiferromagnet
A polycrystalline sample of vesignieite BaCu3V2O8(OH)2 comprising a nearly
ideal kagome lattice composed of Cu2+ ions carrying spin 1/2 has been
synthesized and studied by magnetization and heat capacity measurements.
Magnetic susceptibility shows a neither long range order, a spin glass
transition nor a spin gap down to 2 K, in spite of a moderately strong
antiferromagnetic interaction of J/kB = 53 K between nearest-neighbor spins. A
broad peak observed at a temperature corresponding to 0.4J in intrinsic
magnetic susceptibility indicates a marked development of the short-range
order. The ground state of vesignieite is probably a gapless spin liquid or is
accompanied by a very small gap less than J/30.Comment: 4 pages, 5 figure
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