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1.
2.
Luke Pebody 《Journal of Combinatorial Theory, Series A》2006,113(3):551-555
Answering a question of Körner and Simonyi, this paper gives a strongly consecutive repeat-free code of maximal size in [b]n. 相似文献
3.
G. M. Luke L. P. Le B. J. Sternlieb Y. J. Uemura J. H. Brewer R. Kadono R. F. Kiefl S. R. Kreitzman T. M. Riseman C. E. Stronach M. Davis S. Uchida H. Takagi Y. Tokura Y. Hidaka T. Murakami E. A. Early J. T. Markert M. B. Maple C. L. Seaman 《Hyperfine Interactions》1991,63(1-4):311-317
We report muon spin relaxation/rotation measurements on sintered powder samples of Nd2−x
Ce
x
CuO4−y
and a large single crystal of Nd2CuO4−y
. We find an electronic phase diagram which is quite similar to that of hole-doped superconductors such as La2−x
Sr
x
CuO4−y
, although the doping of electrons into the system is less efficient in destroying the static moments on the copper spins.
Static magnetic order in Nd2CuO4−y
appears below about 250 K, and two spin reorientations are seen atT=75 K andT=35 K. Measurements of the magnetic field penetration depth have been unsuccessful due to the rare-earth paramagnetism of
these materials. 相似文献
4.
G. M. Luke L. P. Le B. J. Sternlieb Y. J. Uemura J. H. Brewer R. Kadono R. F. Kiefl S. R. Kreitzman T. M. Riseman C. L. Seaman Y. Dalichaouch M. B. Maple J. D. Garrett 《Hyperfine Interactions》1991,64(1-4):517-522
We have performed both zero field and high transverse field measurements at dilution refrigerator temperatures on a number of heavy electron systems, examining the superconducting and magnetic properties of these interesting materials. Among the materials studied to date are UBe13, URu2Si2 and U6Fe. The magnetic field penetration depth in the superconducting state of UBe13 is greater than 10000 Å, as no increase in the transverse field relaxation rate is observed belowT c . A sharp increase in the precession frequency is seen, starting atT c . This frequency shift shows little temperature dependence at low temperature; we found no clear evidence for unconventional superconductivity in this material. Zero field measurements in URu2Si2 show the weak antiferromagnetic transition at 17.5 K. Finally, we we found no clear evidence for unconventional superconductivity in this material. Zero field measurements in URu2Si2 show the weak antiferromagnetic transition at 17.5 K. Finally, we have observed relaxation in high transverse field due to the formation of a flux lattice in U6Fe, a material where the electron effective mass is rather lighter than in other heavy fermion systems. The relaxation exhibits a sharp onset atT c=3.9 K, and is flat at low temperatures as expected for a conventional superconductor. 相似文献
5.
Luke O'Connor 《Journal of Cryptology》1994,7(3):133-151
We analyze a very general class of algorithms for constructingm-bit invertible S-boxes called bit-by-bit methods. The method builds an S-box one entry at a time, and has been proposed by
Adams and Tavares [2] and Forre [11] to construct S-boxes that satisfy certain cryptographic properties such as nonlinearity
and the strict avalanche criterion. We prove, both theoretically and empirically, that the bit-by-bit method is infeasible
form>6.
The author is currently employed by the Distributed System Technology Center (DSTC), Brisbane, Australia. Correspondence should
be sent to ISRC, QUT Gardens Point, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001, Australia. 相似文献
6.
The communication infrastructure of a mobile computing environment can be based on the structure of a cellular/microcellular telephone system or a PCS network. In such a system, the occurrence of handoffs cannot be avoided and when handoffs occur, wireless links held by mobile computers crossing cell boundaries may be forced to terminate. The probability that a handoff access request will result in forced termination has a significant effect on the performance of a mobile computing environment, as does the probability that an initial access request will be blocked. Although some research has been done on initial and handoff accesses in cellular/microcellular telephone systems and PCS networks, the analytical models used in this research are not appropriate for mobile computing, since unlike a telephone, a mobile computer may use several channels at once. In this paper, we develop an analytical model to study initial and handoff accesses in a mobile computing environment. The model is based on a multi-dimensional continuous time Markov chain. The accuracy of the model is verified by comparison with simulation results. We then use the model to find a practical approach to balancing the initial access blocking probability and avarage forced termination probability of a connection in a mobile computing network.This research was supported by the National Science Council, ROC, under grant NSC 85-2213-E-009-063. 相似文献
7.
R. Kadono R. F. Kiefl J. H. Brewer G. M. Luke T. Pfiz T. M. Riseman B. J. Sternlieb 《Hyperfine Interactions》1991,64(1-4):635-640
The diffusion rate of muonium in the III–V compound semiconductor GaAs has been determined from measurements of muon spinT
1 relaxation induced by motion in the presence of nuclear hyperfine interactions. It is shown for the first time in a semiconductor
that (a) there is a crossover of the transport mechanism at about 90 K from stochastic to zero-phonon hopping, as evidenced
by a steep rise in the hop rate at lower temperatures, and that (b) the muonium diffuses at the hop rate of 1010 s−1 (corresponding diffusion constantD≈10−6 cm2s−1) at lower temperatures as well as at room temperature. 相似文献
8.
John J. Porter Joel Luke Murray Kenneth B. Takvorian 《Journal of heterocyclic chemistry》1973,10(1):43-46
The complexing ability of derivatives of azobenzene (I) is well known (I) and responsible for the production of a wide variety of dyestuffs and analytical chemicals. While the azo group generally participates in the coordination, the determination of the degree of its interaction is complicated by other functional groups which are also coordinated with the transition metal. In a previous publication (2), we reported the preparation of the silver and palladium complexes of benzo[c]cinnoline (II) and proposed that these results might be used to explain the electron donor properties of azobenzene. We are now reporting the preparation of some additional complexes with ligands containing the azo group. 相似文献
9.
A new spectrophotometric method for the determination of traces of tin in steel is presented. The tin is isolated by an acid sulfide separation and a double carbamate-chloroform extraction and then determined by a phenylfluorone method in which the selectivity is increased by the use of peroxide and oxalate as masking agents and the sensitivity is increased by extracting the colored tin compound into a small volume of MIBK for the spectrophotometric analysis. 相似文献
10.
A total internal reflection (TIR)-based biochip utilizing a polymer-filled cavity with a micromirror sidewall has been designed and fabricated. The implementation of the micromirror sidewall cavity facilitates precise alignment of the excitation light beam into the system. The incident angle of illumination can be easily modified by selecting polymers of different indices of refraction while optical losses are minimized. The design enables the hybrid, vertical integration of a laser diode and a CCD camera, resulting in a compact optical system. Brownian motion of fluorescent microspheres and real-time photobleaching of rhodamine 6G molecules is demonstrated. The proposed TIR-based chip simplifies current TIR optical configurations and could potentially be used as an optical-microfluidic platform for an integrated lab-on-a-chip microsystem. 相似文献