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991.
Starting with the unification hypothesis of mixings of quarks and leptons and small quark-like mixings at the see-saw scale,
we find that two large mixings for νe —νx03BC; andv
μ—v
τ at the weak scale are obtained as a result of renormalization group evolution and radiative magnification if the three neutrinos
are quasi degenerate in masses and possess the same CP parity. We also find thatU
e3
remains small and well within the CHOOZ-Palo Verde bound since the correspondingV
ub
for CKM mixing is very small. Several testable pedictions are pointed out. 相似文献
992.
A. Schaufuß P. Roßbach I. Uhlig R. Szargan 《Analytical and bioanalytical chemistry》1997,358(1-2):262-265
The systems galena/2-mercaptobenzothiazole (MBT) and pyrite/MBT have been studied using synchrotron radiation excited photoelectron spectroscopy (SRXPS). The chemisorption of MBT and the multilayer formation of 2,2′-dithiobis(benzothiazole) (BBTD) are evidenced by additional structures, observed beside the substrate signals, in the S2p-spectra of cleaved mineral surfaces after adsorption of MBT. The amount of the complex remains constant at concentrations as high as 10–5 mol/L whereas the amount of BBTD increases. From the dependence of the adsorbate intensities on the excitation energy the conclusion can be drawn that an overlayer of BBTD on a chemisorbed layer of MBT is formed. The very weak adsorption of MBT on pyrite in alkaline solutions may explain the selective flotation of galena from pyrite in alkaline media. 相似文献
993.
Contingent epiderivatives and set-valued optimization 总被引:24,自引:0,他引:24
In this paper we introduce the concept of the contingent epiderivative for a set-valued map which modifies a notion introduced by Aubin [2] as upper contingent derivative. It is shown that this kind of a derivative has important properties and is one possible generalization of directional derivatives in the single-valued convex case. For optimization problems with a set-valued objective function optimality conditions based on the concept of the contingent epiderivative are proved which are necessary and sufficient under suitable assumptions. 相似文献
994.
G. G. Bondarenko A. I. Bazhin A. P. Korzhavyi V. I. Kristya R. D. Aitov 《Technical Physics》1998,43(9):1121-1122
The electric field at the surface of a charge spot created by an ion beam on a dielectric coating of a target is calculated.
An expression is obtained which relates the surface potential of the insulator to the potential of the collector corresponding
to saturation of the collector secondary-electron current. It permits determination of the potential drop across the oxide
layer of a cold cathode without introducing complications in the construction of the experimental apparatus.
Zh. Tekh. Fiz. 68, 126–128 (September 1998) 相似文献
995.
R. F. Bilyalov 《Russian Physics Journal》1998,41(11):1134-1138
A covariant spinor derivative is constructed in arbitrary reference frames and also in coordinates, with specified arbitrary
linear connectedness.
Kazan State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 78–83, November, 1998. 相似文献
996.
We report on first experiments combining quasi-digital highly selective etching and atomic force microscopy (AFM) to examine the interior interfaces of semiconductor heterostructures. Lattice matched (GaIn)As/InP heterostructures grown by metalorganic vapour-phase epitaxy (MOVPE) are taken as a model system to check the capabilities of this new method. Standard selective etchants for different material systems have been optimized in selectivity and etch rate to achieve a quasi-digital etching behaviour. In this way, the real structure of interior interfaces can be determined by AFM. We find a significant difference between the surface of the heterostructure and the interior interfaces. 相似文献
997.
For a real Enriques surface Y we prove that every homology class in H1(Y (R), Z/2) can be represented by a real algebraic curve if and only if all connected components of Y(R) are orientable. Furthermore, we give a characterization of real Enriques surfaces which are Galois-Maximal and/or Z-Galois-Maximal and we determine the Brauer group of any real Enriques surface Y. 相似文献
998.
The magnetization and paramagnetic susceptibility of the system of compounds Zn1−x
CuxCr2S4 (0<x⩽1) are investigated at low temperatures. It is shown that as the content of Cu increases the system exhibits a transition
from an antiferromagnetic to a ferromagnetic state.
Fiz. Tverd. Tela (St. Petersburg) 40, 278–279 (February 1998) 相似文献
999.
J.M. Chatterjee S. Basu-Roy S.S. Ghugre S. Chattopadhyay R.P. Singh G.O. Rodrigues R.K. Chattopadhyay R.K. Bhowmik 《The European Physical Journal A - Hadrons and Nuclei》1998,1(1):55-59
A search for new isomers of nanosecond lifetimes were carried out in 153Eu via the 150Nd(7Li,xnγ) reaction. The single particle angular momentum alignment and dynamical moment of inertia estimated from the experimental
data indicate a configuration change at rotational energy ħω∼ 0.30 MeV. A decrease of B(E2) values is also observed at the
same frequency. An isomeric level is identified at an excitation energy of 3100 keV (Jπ=35/2−) which corresponds to this frequency. The lifetime of the level is found to be 8.6 ± 1.3 nanosecond.
Received: 22 April 1997 / Revised version: 26 September 1997 相似文献
1000.
B. Dubrulle F.-M. Bréon F. Graner A. Pocheau 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,4(1):89-94
We consider fields which take random values over several decades. Starting from physical examples, we postulate that scale is not an absolute quantity. We then establish the equivalence between two existing approaches based on scale symmetry arguments as general as possible.
This yields a classification of log-infinitely divisible laws, possibly universal. The physical significance of the parameters
entering in the classification is discussed.
Received: 7 November 1997 / Received in final form: 26 March 1998 / Accepted: 30 March 1998 相似文献