222,501 research outputs found
Progress of research on water vapor lidar
Research is summarized on applications of stimulated Raman scattering (SRS) of laser light into near infrared wavelengths suitable for atmospheric monitoring. Issues addressed are conversion efficiency, spectral purity, optimization of operating conditions, and amplification techniques. A Raman cell was developed and built for the laboratory program, and is now available to NASA-Langley, either as a design or as a completed cell for laboratory or flight applications. The Raman cell has been approved for flight in NASA's DC-8 aircraft. The self-seeding SRS technique developed here is suggested as an essential improvement for tunable near-IR DIAL applications at wavelengths of order 1 micrometer or greater
From Doubled Chern-Simons-Maxwell Lattice Gauge Theory to Extensions of the Toric Code
We regularize compact and non-compact Abelian Chern-Simons-Maxwell theories
on a spatial lattice using the Hamiltonian formulation. We consider a doubled
theory with gauge fields living on a lattice and its dual lattice. The Hilbert
space of the theory is a product of local Hilbert spaces, each associated with
a link and the corresponding dual link. The two electric field operators
associated with the link-pair do not commute. In the non-compact case with
gauge group , each local Hilbert space is analogous to the one of a
charged "particle" moving in the link-pair group space in a
constant "magnetic" background field. In the compact case, the link-pair group
space is a torus threaded by units of quantized "magnetic" flux,
with being the level of the Chern-Simons theory. The holonomies of the
torus give rise to two self-adjoint extension parameters, which form
two non-dynamical background lattice gauge fields that explicitly break the
manifest gauge symmetry from to . The local Hilbert space
of a link-pair then decomposes into representations of a magnetic translation
group. In the pure Chern-Simons limit of a large "photon" mass, this results in
a -symmetric variant of Kitaev's toric code, self-adjointly
extended by the two non-dynamical background lattice gauge fields. Electric
charges on the original lattice and on the dual lattice obey mutually anyonic
statistics with the statistics angle . Non-Abelian
Berry gauge fields that arise from the self-adjoint extension parameters may be
interesting in the context of quantum information processing.Comment: 38 pages, 4 figure
A methodological approach to developing the model of correlation between economic development and environmental efficiency on the basis of company's non-financial reports
Having reviewed the most widely used international non-financial reporting standards, GRI was identified as the optimal standard for the Russian context. The environmental component of the GRI G4 guidelines and the contribution of each aspect to the overall sustainability picture were analysed. Over time, the value of biological resources increases, and therefore, a company’s economic development cannot continue in isolation. To determine the degree of harmony between economic development and ecological condition of the territories involved, new approaches and methods are required. Based on statistical methods, a model of correlation between economic development and environmental efficiency was developed that uses non-financial reporting data. The model can be used by oil and gas companies, and its general principles — by other industries. The results may interest stakeholders and serve as a platform for forecasting and making administrative decisions aimed at achieving harmony between economic development and environmental efficiency. The model was tested on the largest oil and gas Russian company “Surgutneftegaz” data. A positive correlation was shown between the two systems of its sustainable development: economy and ecology. The results obtained demonstrate the company’s strong commitment to conservation. Further research may yield more profound results, contributing to broader sustainable development
Noise In Nonohmic Regimes Of Disordered Systems
We present here a short review of mainly experimental properties of noise as
disordered systems are driven into non-ohmic regimes by applying voltages of
few volts only. It is found that the noise does not simply follow the
resistance in that the direction of change of noise could be opposite to that
of resistance. It is discussed how this and other properties make the noise a
complementary and incisive tool for studying complex systems, particularly its
dynamic properties. Study of noise in non-ohmic regimes in physical systems is
rather in a nascent stage. Some of the open issues are highlighted.Comment: 9 Pages, 7 figures. Reported in Unsolved Problems of Noise and
Fluctuations: UPoN 2005, Gallipoli, Italy, June 6-10, 200
Fundamental constants and tests of theory in Rydberg states of one-electron ions
The nature of the theory of circular Rydberg states of hydrogenlike ions
allows highly-accurate predictions to be made for energy levels. In particular,
uncertainties arising from the problematic nuclear size correction which beset
low angular-momentum states are negligibly small for the high angular-momentum
states. The largest remaining source of uncertainty can be addressed with the
help of quantum electrodynamics (QED) calculations, including a new
nonperturbative result reported here. More stringent tests of theory and an
improved determination of the Rydberg constant may be possible if predictions
can be compared with precision frequency measurements in this regime. The
diversity of information can be increased by utilizing a variety of
combinations of ions and Ryberg states to determine fundamental constants and
test theory.Comment: 10 pages; LaTe
Graphical Tensor Product Reduction Scheme for the Lie Algebras so(5) = sp(2), su(3), and g(2)
We develop in detail a graphical tensor product reduction scheme, first
described by Antoine and Speiser, for the simple rank 2 Lie algebras so(5) =
sp(2), su(3), and g(2). This leads to an efficient practical method to reduce
tensor products of irreducible representations into sums of such
representations. For this purpose, the 2-dimensional weight diagram of a given
representation is placed in a "landscape" of irreducible representations. We
provide both the landscapes and the weight diagrams for a large number of
representations for the three simple rank 2 Lie algebras. We also apply the
algebraic "girdle" method, which is much less efficient for calculations by
hand for moderately large representations. Computer code for reducing tensor
products, based on the graphical method, has been developed as well and is
available from the authors upon request.Comment: 43 pages, 18 figure
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