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981.
The probability measure of X = (x0,…, xr), where x0,…, xr are independent isotropic random points in n (1 ≤ r ≤ n ? 1) with absolutely continuous distributions is, for a certain class of distributions of X, expressed as a product measure involving as factors the joint probability measure of (ω, ?), the probability measure of p, and the probability measure of . Here ω is the r-subspace parallel to the r-flat η determined by X, ? is a unit vector in ω⊥ with ‘initial’ point at the origin [ω⊥ is the (n ? r)-subspace orthocomplementary to ω], p is the norm of the vector z from the origin to the orthogonal projection of the origin on η, and , where α is a scale factor determined by p. The probability measure for ω is the unique probability measure on the Grassmann manifold of r-subspaces in n invariant under the group of rotations in n, while the conditional probability measure of ? given ω is uniform on the boundary of the unit (n ? r)-ball in ω⊥ with centre at the origin. The decomposition allows the evaluation of the moments, for a suitable class of distributions of X, of the r-volume of the simplicial convex hull of {x0,…, xr} for 1 ≤ r ≤ n. 相似文献
982.
Harold Kadin 《Microchemical Journal》1975,20(2):236-241
Reaction of Δ1,4-3-keto steroids with zinc and acid produces a characteristic fluorescence. Estrogenic, 3-keto and Δ4-3-keto steroids did not yield this fluorescence. Stabilization of the dienone fluorescence by extraction into butyl ether allowed quantitation of triamcinolone acetonide in liquid formulations in which this dienone was present at the 0.01% level. A mechanism for the reaction is proposed. 相似文献
983.
An elementary proof of the prime number theorem in the form $$\psi (x) - x = O(x exp\{ - (\log x)^{\tfrac{1}{7}} (log log x)^{ - 2} \} )$$ is given. The proof uses a generalization of Selberg's formula and a tauberian argument. 相似文献
984.
985.
Robin S. McDowell Martin J. Reisfeld Harold W. Galbraith Burton J. Krohn Herbert Flicker R.Craig Kennedy Jack P. Aldridge Norris G. Nereson 《Journal of Molecular Spectroscopy》1980,83(2):440-450
The 16-μm bending fundamentals (ν4) of 12CF4, 13CF4, and 14CF4 have been observed at Doppler-limited resolution using a tunable PbSnSe semiconductor diode laser. The tetrahedral splittings of the rotational manifolds have been observed in all three branches, and in particular the dense and partially overlapping transitions in the Q branches have been resolved and assigned. A least-squares fit of the Hamiltonian, including off-diagonal terms, yielded five scalar and three tensor spectroscopic constants for each of the three isotopes. From these constants the upper-state rotational constant B4 and the Coriolis constant ζ4 have been calculated, together with some of the other molecular constants. An absorption feature at about 0.18 cm?1 to the red of the main Q branch of each isotopic species has been identified as the Q branch of (ν2 + ν4) ? ν2, which is the transition that lases when CF4 is pumped by a CO2 laser at 9.4 μm (i.e., in ν2 + ν4). 相似文献
986.
987.
Oncel N Hallback AS Zandvliet HJ Speets EA Ravoo BJ Reinhoudt DN Poelsema B 《The Journal of chemical physics》2005,123(4):044703
Single-electron tunneling through Au substrate-alkanethiol-Pd cluster-tip junctions is investigated with scanning tunneling spectroscopy. The measured I(V) curves reveal several characteristic features of the Coulomb blockade, namely, the presence of a Coulomb gap and a Coulomb staircase. By using the orthodox theory of single-electron tunneling, the capacitances and resistances of the double junction system as well as the fractional charge are extracted from the experimental data. 相似文献
988.
989.
990.
Hwaling Harold Szu 《Optics Communications》1980,32(2):229-234
Simultaneous multiple-path looks at a moving object (MO) of low signal to noise ratio (SNR) is proposed using an array of telescopes without using either interferometric or adaptive optics techniques. Instead, proper Affine overlays, of all looks through nonisoplanatic regions, give a better SNR and a better turning view in the real time and image plane, and can be furthermore integrated temporally using Affine transformation to yield new templates of a MO. Thereby a scheme of open, self-taught and therefore smart pattern recognition of MO's becomes possible. The system performance of a multi-opto-sensor-Affine (MOSA) system is generally derived in terms of system parameters and field conditions. Geometric constructions of Affine transformations are shown to be either area-ration preserving among three control picture elements (pixels), which are proved to be sufficient using Euler's theorem of solid body motion, or the first order moment of area-ratio preserving, when more than three pixels are needed due to poor SNR. 相似文献