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61.
In this paper, the authors studied certain properties of the estimate of Liang and Krishnaiah (1985, J. Multivariate Anal. 16, 162–172) for multivariate binary density. An alternative shrinkage estimate is also obtained. The above results are generalized to general orthonormal systems. 相似文献
62.
Gauss periods give an exponentiation algorithm that is fast for many finite fields but slow for many other fields. The current paper presents a different method for construction of elements that yield a fast exponentiation algorithm for finite fields where the Gauss period method is slow or does not work. The basic idea is to use elements of low multiplicative order and search for primitive elements that are binomial or trinomial of these elements. Computational experiments indicate that such primitive elements exist, and it is shown that they can be exponentiated fast. 相似文献
63.
Neodymium-substituted Bi4Ti3O12 (BNdT) thin films were prepared by a chemical solution deposition technique on platinum- coated silicon substrates. All of
the samples were annealed at the relatively low temperature of 600 °C by a rapid thermal annealing process in different atmospheres,
such as O2, air, and nitrogen, and vacuum. Irrespective of different annealing atmospheres, all of the BNdT thin films exhibit good
ferroelectric properties, such as a saturated hysteresis loop, good fatigue endurance, and low leakage current density. A
large remanent polarization (Pr) of ∼48 μC/cm2 with an electric field of 240 kV/cm was observed from the BNdT thin film annealed in O2 atmosphere. The BNdT thin films annealed in nitrogen and vacuum, at reduced oxygen partial pressures, exhibit smaller Pr than that annealed in oxygen. The difference of Pr of the BNdT thin films annealed in different atmospheres may originate from differences in the grain sizes and the number
of oxygen vacancies.
PACS 77.55.+f; 77.80.-e; 77.80.Fm; 81.15.-z 相似文献
64.
Thin Ca films were evaporated on Si(1 1 1) under UHV conditions and subsequently annealed in the temperature range 200–650 °C. The interdiffusion of Ca and Si was examined by ex situ Auger depth profiling. In situ monitoring of the Si 2p core-level shift by X-ray photoemission spectroscopy (XPS) was employed to study the silicide formation process. The formation temperature of CaSi2 films on Si(1 1 1) was found to be about 350 °C. Epitaxial growth takes place at T≥400 °C. The morphology of the films, measured by atomic force microscopy (AFM), was correlated with their crystallinity as analyzed by X-ray diffraction (XRD). According to measurements of temperature-dependent I–V characteristics and internal photoemission the Schottky-barrier height of CaSi2 on Si(1 1 1) amounts to qΦBn=0.25 eV on n-type and to qΦBp=0.82 eV on p-type silicon. 相似文献
65.
Many operators in Banach spaces occur as the integration operator of a suitable vector measure; their compactness is completely described in [19]. However, many important spaces X in analysis (and integration operators in such spaces) do not fall into this scheme because X is not normable. Characterizing the compactness of integration operators in this setting is the aim of this note. The methods and techniques employed are quite different to the Banach space arguments used in [19]. 相似文献
66.
W.-H. Chen 《Archiv der Mathematik》2002,79(5):396-400
Consider the class of closed Riemannian manifolds M of dimension dim(M) \geqq 3 \dim(M) \geqq 3 , Ricci curvature Ric(M) \geqq -(n - 1) \textrm{Ric}(M) \geqq -(n - 1) , diameter diam(M) < D and almost maximal volume. We show that the isomorphism types of fundamental groups characterize the diffeomorphism types of manifolds in such a class. In particular, it can be viewed as a generalization of the well-known Mostows rigidity theorem and a finiteness theorem. 相似文献
67.
I. L. Davies K. E. Markides M. L. Lee M. W. Raynor K. D. Bartle 《Journal of separation science》1989,12(4):193-207
Although coupled liquid chromatographygas chromatography (LC-GC) was first demonstrated ten years ago, only in the last few years has there been a sudden surge of interest in the technique. Approximately 70% of the total number of LC-GC applications have been published in the last two years (1987–88) alone. This review categorizes LC-GC publications into four main application areas: fossil fuels, foods, environmental samples, biologiical/pharmaceutical samples, and miscellaneous samples. Multidimensional separations carried out using other coupled-column chromatographic techniques (such as supercritical fluid chromatography (SFC) with GC, and on-line trace enrichment-GC) have also been included in this review. 相似文献
68.
Jun-tao Chang Joerg Evers Marian O. Scully M. Suhail Zubairy 《量子光学学报》2006,12(B08):77-77
We propose a scheme to obtain the distance of two identical atoms placed inside the standing wave field by monitoring the collective resonance fluorescence spectrum emitted by the two particles. We find three different parameter ranges, depending on the distance of the atoms as compared to the transition wavelength. For large interparticle distances, dipole-dipole coupling is negligible, and the main system evolution arises from the interaction with the standing wave field. In the small-distance limit, the dynamics is dominated by the dipole-dipole interaction. Finally, in the intermediate region, a rich interplay of the various couplings arises, which however is lifted for strong driving laser fields. The present measurement procedure allows us to distinguish the three cases. In each of the cases, we show how to determine the distance of the two particles and their respective positions relative to the nodes of the standing wave field with fractional-wavelength precision. 相似文献
69.
Critical problems of the present approach of electrolytes for Solid Oxide Fuel Cells (SOFCs) for commercialization are discussed.
Major progress is expected from the development of materials based on the “SEA (Single Element Arrangement)” concept. The
galvanic cell consists in this case basically of a single chemically homogeneous compound, which functions as electrodes at
high and low activity and as electrolyte at intermediate activities of the electroactive component.
In view of the large structural flexibility of the chemical nature of the constitutents, we explored perovskite (ABO3)-type compounds to be used as SEAs for SOFCs. Results of studies on Pr-substituted LSGM and Fe-substituted SrSnO3 perovskite-type oxides are presented. For instance, SrSn1-xFexO3-δ with x=0.1 exhibits p and n-type electronic conduction at the cathode and anode sides of the SOFC, respectively, while oxide
ion conduction prevails at intermediate oxygen partial pressures. The SEA concept is also applicable for other devices in
the field of Ionics. 相似文献
70.
S.-Y. Sheu D.-Y. Yang H.L. Selzle E.W. Schlag 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,20(3):557-563
Charge transport is one important example of signal transduction in a protein which is responsible for action at a distance,
and is a fundamental process in biochemical action. A model is presented in which electronic effects interact with motional
processes to combine into a bifunctional model. This model is investigated with new detailed molecular dynamics calculations
and successfully explains such action at a distance.
Received 1st February 2002 / Received in final form 26 May 2002 Published online 13 September 2002 相似文献