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11.
H. G. Bohlen W. von Oertzen R. Kalpakchieva B. Gebauer S. M. Grimes A. Lenz T. N. Massey M. Milin Ch. Schulz Tz. Kokalova S. Torilov S. Thummerer 《Physics of Atomic Nuclei》2003,66(8):1494-1500
The structure of neutron-rich beryllium isotopes has been investigated using different heavy-ion-induced transfer reactions. In neutron transfer reactions, the population of final states shows a strong sensitivity to the chosen core nucleus, i.e., the target nuclei 9Be or 10Be, respectively. Molecular rotational bands up to high excitation energies are observed with 9Be as the core due to its pronounced 2α-cluster structure, whereas only a few states at low excitation energies are populated with 10Be as the core. For 11Be, a detailed investigation has been performed for the three states at 3.41, 3.89, and 3.96 MeV, which resulted in the most probable spin-parity assignments 3/2+, 5/2?, and 3/2?, respectively. Furthermore, we have studied particle-hole states of 16C using the 13C(12C, 9C)16C reaction and found 14 previously unknown states. Using the 12C(12C, 9C)15C reaction, five new states were observed for 15C. 相似文献
12.
We study the duality of reconstruction systems, which are g-frames in a finite dimensional setting. These systems allow redundant linear encoding-decoding schemes implemented by the so-called dual reconstruction systems. We are particularly interested in the projective reconstruction systems that are the analogue of fusion frames in this context. Thus, we focus on dual systems of a fixed projective system that are optimal with respect to erasures of the reconstruction system coefficients involved in the decoding process. We consider two different measures of the reconstruction error in a blind reconstruction algorithm. We also study the projective reconstruction system that best approximate an arbitrary reconstruction system, based on some well known results in matrix theory. Finally, we present a family of examples in which the problem of existence of a dual projective system of a reconstruction system of this type is considered. 相似文献
13.
Pedro G. Massey Mariano A. Ruiz Demetrio Stojanoff 《Linear algebra and its applications》2012,436(3):447-464
We consider reconstruction systems (RS’s), which are G-frames in a finite dimensional setting, and that includes the fusion frames as projective RS’s. We describe the spectral picture of the set of RS operators for the projective systems with fixed weights. We also introduce a functional defined on dual pairs of RS’s, called the joint potential, and study the structure of the minimizers of this functional. In the case of irreducible RS’s the minimizers are characterize as the tight systems. In the general case we give spectral and geometric characterizations of the minimizers of the joint potential. At the end of the paper we show several examples that illustrate our results. 相似文献
14.
Sridhar Ravi Simon Watkins Jon Watmuff Kevin Massey Phred Petersen Matthew Marino Anuradha Ravi 《Experiments in fluids》2012,53(3):637-653
Micro Air Vehicles (MAVs) can be difficult to control in the outdoor environment as they fly at relatively low speeds and are of low mass, yet exposed to high levels of freestream turbulence present within the Atmospheric Boundary Layer. In order to examine transient flow phenomena, two turbulence conditions of nominally the same longitudinal integral length scale (Lxx/c?=?1) but with significantly different intensities (Ti?=?7.2?% and 12.3?%) were generated within a wind tunnel; time-varying surface pressure measurements, smoke flow visualization, and wake velocity measurements were made on a thin flat plate airfoil. Rapid changes in oncoming flow pitch angle resulted in the shear layer to separate from the leading edge of the airfoil even at lower geometric angles of attack. At higher geometric angles of attack, massive flow separation occurred at the leading edge followed by enhanced roll up of the shear layer. This lead to the formation of large Leading Edge Vortices (LEVs) that advected at a rate much lower than the mean flow speed while imparting high pressure fluctuations over the airfoil. The rate of LEV formation was dependent on the angle of attack until 10° and it was independent of the turbulence properties tested. The fluctuations in surface pressures and consequently aerodynamic loads were considerably limited on the airfoil bottom surface due to the favorable pressure gradient. 相似文献
15.
Higgins EM Sherwood JA Lindsay AG Armstrong J Massey RS Alder RW O'Donoghue AC 《Chemical communications (Cambridge, England)》2011,47(5):1559-1561
pK(a) values of 19.8-28.2 are reported for the conjugate acids of a large series of NHCs in water. The effects of ring size, N-substituent and C(4)-C(5) saturation on pK(a) are discussed. 相似文献
16.
17.
Summary The paper describes tests for liquid chromatographs to assess the autosampler and pump flow rate precision; suitability of
the instrument for normal phase chromatography; UV detector performance; and external band broadening characteristics. Tests
for mixing and proportioning characteristics of solvent pumps and performance of diode array detectors are also considered.
These tests are designed to evaluate the performance of both newly released liquid chromatography equipment and equipment
already in operation. Data from evaluations carried out by instrument manufacturer’s and suppliers is reported and discussed.
This data offers specifications to a common format for initial selection of instruments prior to purchase. 相似文献
18.
19.
Matthew C. Ball David S. Brown Alan G. Massey Denys A. Wickens 《Journal of organometallic chemistry》1981,206(3):265-277
Perfluorotribenzo[b,e,h][1,4,7]trimercuronin forms adducts of 1 : 1, 1 : 2 and 1 : 3 stoicheiometry with a variety of polar organic molecules. The structure of the 1 : 1 adduct with 4-phenylpyridine was solved by X-ray methods to an R factor of 7.4% for 3528 observed reflections. 相似文献
20.
Campbell Massey 《Experimental Mechanics》1967,7(3):124-126
This paper shows how an electrical-resistance analog based on the “conjugate-beam” concept and developed to simulate the elastic behavior of beams in the plane of loading may be used to examine the lateral buckling behavior of beams. 相似文献