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51.
52.
We present a locally superconformal invariant theory of supergravity which is gauge equivalent to the usual, Poincaré, supergravity. This is achieved by means of a compensating scalar supermultiplet. This shows that local superconformal symmetry can be made compatible with gravitational phenomenology. 相似文献
53.
Sugita M Yamaguchi A Yamagiwa N Handa S Matsunaga S Shibasaki M 《Organic letters》2005,7(23):5339-5342
[reaction, structure: see text] Chiral Y{N(SiMe3)2}3/linked-BINOL catalyst generated Y-enolate in situ from various hydroxyketones (R2 = aryl, heteroaryl). Beta-amino-alpha-hydroxy ketones (R1 = aryl, heteroaryl, alkenyl) were obtained syn-selectively (up to 96/4) in high ee (up to 98%) and good yield (up to 98% yield). 相似文献
54.
We report the first experimental demonstration of an optical quantum controlled-NOT gate without any path interference, where the two interacting path interferometers of the original proposals have been replaced by three partially polarizing beam splitters with suitable polarization dependent transmittance and reflectance. The performance of the device is evaluated using a recently proposed method, by which the quantum process fidelity and the entanglement capability can be estimated from the 32 measurement results of two classical truth tables, significantly less than the 256 measurement results required for full quantum tomography. 相似文献
55.
Let T = T(A, D) be a self-affine attractor in
defined by an integral expanding matrix A and
a digit set D. In the
first part of this paper, in connection with canonical number systems,
we study connectedness of T when
D corresponds to the set of
consecutive integers
. It is shown that in
and
, for any integral expanding matrix A, T(A, D) is connected.
In the second part, we study connectedness of Pisot dual tiles, which
play an important role in the study of
-expansions, substitutions and
symbolic dynamical systems. It is shown that each tile of the dual
tiling generated by a Pisot unit of degree 3 is arcwise connected. This
is naturally expected since the digit set consists of consecutive
integers as above. However surprisingly, we found families of
disconnected Pisot dual tiles of degree 4. We even give a simple
necessary and sufficient condition of connectedness of the Pisot dual
tiles of degree 4. Detailed proofs will be given in [4].
Received: 2 March 2003 相似文献
56.
In the present paper we give an overview of topological properties of self-affine tiles. After reviewing some basic results on self-affine tiles and their boundary we give criteria for their local connectivity and connectivity. Furthermore, we study the connectivity of the interior of a family of tiles associated to quadratic number systems and give results on their fundamental group. If a self-affine tile tessellates the space the structure of the set of its ‘neighbors’ is discussed. 相似文献
57.
Takada K Uehara T Nakao Y Matsunaga S van Soest RW Fusetani N 《Journal of the American Chemical Society》2004,126(1):187-193
Three new alpha-glucosidase inhibitors, schulzeines A-C (1-3), were isolated from the marine sponge Penares schulzei. Their structures were elucidated by spectral analysis and chemical degradations to be the isoquinoline alkaloids, encompassing two amino acids, and C(28) fatty acid, the last of which was sulfated. Absolute stereochemistry of schulzeines was determined by application of the modified Mosher analysis to fragments obtained by chemical degradation. Schulzeines A-C inhibit alpha-glucosidase with IC(50) values of 48-170 nM. 相似文献
58.
Electric polarization in insulators is represented by the transferred charge through a shift of the Bloch wave functions induced by an adiabatic change of external parameters Q-->. It is found that this covalent/quantum contribution is determined nonlocally by the topological structure in the Q--> space. The condition for the charge pumping for a cyclic change of Q--> is also obtained. Applications of this picture to various organic ferroelectrics and BaTiO3 are discussed. 相似文献
59.
60.
We observed a small-signal gain of Ar2* emission at 126 nm by use of a hollow fiber to guide the high-intensity laser propagation in high-pressure Ar. The small-signal gain coefficient was measured to be 0.05 cm(-1) at 126 nm. Kinetic analysis revealed that the electrons produced by the high-intensity laser through an optical-field-induced ionization process initiated the Ar2* production processes. The increase in the emission intensity was measured to be exp(2.5), with an increase in the fiber length. 相似文献