20,559 research outputs found
On Seismic Waves (Third Paper)
In two previous papers under the present title 1) 2) the authors have presented data on bodily waves. The present paper contains the corresponding data on surface waves (including seismic sea waves), the magnitude and energy of earthquakes, and miscellaneous topics.
The seismograms used were those studied in the previously published investigations; the numbers assigned to individual shocks are as given in the previous papers
On Seismic Waves (Second Paper)
In a first paper under the present title the authors have presented a body of data on travel times. The present paper contains the
corresponding data on amplitudes, periods, velocities, etc., for bodily
waves. It is intended to present data on surface waves in a third paper
Field-Effect Devices Utilizing LaAlO-SrTiO Interfaces
Using LaAlO-SrTiO bilayers, we have fabricated field-effect devices
that utilize the two-dimensional electron liquid generated at the bilayers'
{\textit n}-type interfaces as drain-source channels and the LaAlO layers
as gate dielectrics. With gate voltages well below 1\,V, the devices are
characterized by voltage gain and current gain. The devices were operated at
temperatures up to 100\,{\deg}C.Comment: to be published in Applied Physics Letter
MEASURING PRODUCTION EFFICIENCY USING AGGREGATE DATA
This paper develops a measure of efficiency when data have been aggregated. Unlike the most commonly used efficiency measures, our estimator handles the heteroskedasticity created by aggregation appropriately. Our estimator is compared to estimators currently used to measure school efficiency. Theoretical results are supported by a Monte Carlo experiment. Results show that for samples containing small schools (sample average may be about 100 students per school but sample includes several schools with about 30 students), the proposed aggregate data estimator performs better than the commonly used OLS and only slightly worse than the multilevel estimator. Thus, when school officials are unable to gather multilevel or disaggregate data, the aggregate data estimator proposed here should be used. When disaggregate data is available, standardizing the value-added estimator should be considered.Productivity Analysis,
Experimental Studies of the NaCs 53Π0 and a3Σ+ States
We report high resolution measurements of 372 NaCs 53Π0(v, J) ro-vibrational level energies in the range 0 ≤ v ≤ 22. The data have been used to construct NaCs 53Π0 potential energy curves using the Rydberg–Klein-Rees and inverted perturbation approximation methods. Bound-free 53Π0(v, J) → 1(a)3Σ+ emission has also been measured, and is used to determine the repulsive wall of the 1(a)3Σ+ state and the 53Π0 → 1(a)3Σ+ relative transition dipole moment function. Hyperfine structure in the 53Π0 state has not been observed in this experiment. This null result is explained using a simple vector coupling model
On The Violation Of Marshall-Peierls Sign Rule In The Frustrated Heisenberg Antiferromagnet
We present a number of arguments in favor of the suggestion that the
Marshall-Peierls sign rule survives the frustration in the square-lattice
Heisenberg antiferromagnet with frustrating next-nearest-neighbor (diagonal)
bonds ( model) for relatively large values of the parameter
. Both the spin-wave analysis and the exact-diagonalization data
concerning the weight of Marshall states support the above suggestion.Comment: 8 pages, LaTex, 2 figurs on reques
Pseudoseisms Caused by Abnormal Audibility of Gunfire in California
During the last ten years the Pacific fleet of the United States Navy has occasionally engaged in target practice off the coast of southern California. The sound of this gunfire has often been heard tar inland, especially at night and in the winter season as in Europe on the continent.
The distance between the source and the points of observation was often so great that abnormal audibility is clearly indicated
Induced Time-Reversal Symmetry Breaking Observed in Microwave Billiards
Using reciprocity, we investigate the breaking of time-reversal (T) symmetry
due to a ferrite embedded in a flat microwave billiard. Transmission spectra of
isolated single resonances are not sensitive to T-violation whereas those of
pairs of nearly degenerate resonances do depend on the direction of time. For
their theoretical description a scattering matrix model from nuclear physics is
used. The T-violating matrix elements of the effective Hamiltonian for the
microwave billiard with the embedded ferrite are determined experimentally as
functions of the magnetization of the ferrite.Comment: 4 pages, 4 figure
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