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61.
Yu. M. Tairov N. S. Peev N. A. Smirnova A. A. Kalnin 《Crystal Research and Technology》1986,21(12):1503-1507
In the paper which is divided into three parts the liquid phase epitaxy of SiC by temperature gradient zone melting with the solvent Si Tb is discussed. In the first part the solubility of SiC at different initial compositions of the Si Tb solvent is studied in the temperature range 2000–2500 K. 相似文献
62.
63.
C. Pacher M. Peev 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,59(4):519-525
Integral identities for particular Bloch functions in finite periodic systems are derived. All following statements are proven for a finite domain consisting of an integer number of
unit cells. It is shown that matrix elements of particular Bloch functions with respect to periodic differential operators
vanish identically.
The real valuedness, the time-independence and a summation property of the expectation values of periodic differential
operators applied to superpositions of specific Bloch functions are derived. 相似文献
64.
I. M. Herbauts S. Bettelli H. Hübel M. Peev 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(2):395-406
Some MIT researchers [Phys. Rev. A
75, 042327 (2007)] have recently claimed that
their implementation of the Slutsky-Brandt attack [Phys. Rev. A
57, 2383 (1998); Phys. Rev. A 71, 042312 (2005)] to
the BB84 quantum-key-distribution (QKD) protocol puts the security of this
protocol “to the test” by simulating “the most powerful
individual-photon attack” [Phys. Rev. A 73, 012315
(2006)].
A related unfortunate news feature by a
scientific journal [G. Brumfiel, Quantum cryptography is hacked, News @ Nature (april 2007); Nature 447, 372 (2007)]
has spurred some concern in the QKD community and among the general public
by misinterpreting the implications of this work. The present article
proves the existence of a stronger individual attack on QKD protocols with
encrypted error correction, for which tight bounds are shown, and clarifies
why the claims of the news feature incorrectly suggest a contradiction with
the established “old-style” theory of BB84 individual attacks.
The full implementation of a quantum cryptographic protocol includes a
reconciliation and a privacy-amplification stage, whose choice alters in
general both the maximum extractable secret and the optimal eavesdropping
attack. The authors of [Phys. Rev. A
75, 042327 (2007)] are concerned only with the error-free
part of the so-called sifted string, and do not consider faulty bits,
which, in the version of their protocol, are discarded. When using the
provably superior reconciliation approach of encrypted error correction
(instead of error discard), the Slutsky-Brandt attack is no more optimal
and does not “threaten” the security bound derived by Lütkenhaus [Phys. Rev. A 59, 3301 (1999)].
It is shown that the method of Slutsky and collaborators [Phys. Rev. A
57, 2383 (1998)] can
be adapted to reconciliation with error correction, and that the optimal
entangling probe can be explicitly found. Moreover, this attack fills
Lütkenhaus bound, proving that it is tight (a fact which was not
previously known). 相似文献
65.
Stepanyan S Hicks K Carman DS Pasyuk E Schumacher RA Smith ES Tedeschi DJ Todor L Adams G Ambrozewicz P Anciant E Anghinolfi M Asavapibhop B Audit G Avakian H Bagdasaryan H Ball JP Barrow SP Battaglieri M Beard K Bektasoglu M Bellis M Berman BL Bianchi N Biselli AS Boiarinov S Bouchigny S Bradford R Branford D Briscoe WJ Brooks WK Burkert VD Butuceanu C Calarco JR Carnahan B Chen S Ciciani L Cole PL Coleman A Cords D Corvisiero P Crabb D Crannell H Cummings JP De Sanctis E Degtyarenko PV 《Physical review letters》2003,91(25):252001
In an exclusive measurement of the reaction gammad-->K(+)K(-)pn, a narrow peak that can be attributed to an exotic baryon with strangeness S=+1 is seen in the K(+)n invariant mass spectrum. The peak is at 1.542+/-0.005 GeV/c(2) with a measured width of 0.021 GeV/c(2) FWHM, which is largely determined by experimental mass resolution. The statistical significance of the peak is (5.2+/-0.6)sigma. The mass and width of the observed peak are consistent with recent reports of a narrow S=+1 baryon by other experimental groups. 相似文献
66.
67.
68.
Hentschel S Alzeer J Angelov T Schärer OD Luedtke NW 《Angewandte Chemie (International ed. in English)》2012,51(14):3466-3469
The missing linking: BCNU is a chemotherapy drug that generates an ethylene bridge between N(1) of deoxyguanosine and N(3) of deoxycytidine. No synthesis of a DNA containing this moiety has been reported until now. A new strategy uses a photocaged nucleobase that, when released, generates a highly reactive intermediate which cross-links the opposing DNA strand in a manner analogous to BCNU (see scheme, NBOC=ortho-nitrobenzyloxycarbonyl). 相似文献
69.
Todor Baramov Karlijn Keijzer Dr. Elisabeth Irran Eva Mösker Prof. Dr. Mu‐Hyun Baik Prof. Dr. Roderich Süssmuth 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(32):10536-10542
The E. coli siderophore enterobactin, one of the strongest FeIII chelators known to date, is also capable of binding SiIV under physiological conditions. We report on the synthesis and structural characterization of the tris(catecholate) SiIV–enterobactin complex and its GeIV and TiIV analogues. Comparative structural analysis, supported by quantum‐chemical calculations, reveals the correlation between the ionic radius and the structural changes in enterobactin upon complexation. 相似文献
70.
Order - We show that the poset of copies $\mathbb {P} (\mathbb {Q}_{n} )=\langle \{ f[X]: f\in \text {Emb} (\mathbb {Q}_{n} ) \},\subset \rangle $ of the countable homogeneous universal n-labeled... 相似文献