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31.
K. Lou D. V. Balin V. N. Baturin P. Baumann W. H. Breunlich T. Case K. M. Crowe H. Daniel Yu. S. Grigoriev F. J. Hartmann A. I. Ilyin M. Jeitler P. Kammel B. Lauss J. Marton M. Mühlbauer C. Petitjean G. E. Petrov W. Prymas W. Schott G. G. Semenchuk Yu. V. Smirenin A. A. Vorobyov P. Wojciechowski J. Zmeskal 《Hyperfine Interactions》1993,82(1-4):313-325
A new direct measurement of the final dt sticking probability s using a special data analysis called the survived muon method is presented. The data were obtained at PSI using a high pressure ionization chamber with H/D/T gas mixtures. The method can provide information on final sticking dt +n independent of theoretical models of stripping and initial sticking. It was found:
s=(0.57±0.07±0.02)%. The experiment and the analysis method are discussed in detail. 相似文献
32.
C. Petitjean D. V. Balin V. N. Baturin P. Baumann W. H. Breunlich T. Case K. M. Crowe H. Daniel Yu. S. Grigoriev F. J. Hartmann A. I. Ilyin M. Jeitler P. Kammel B. Lauss K. Lou E. M. Maev J. Marton M. Mühlbauer G. E. Petrov W. Prymas W. Schott G. G. Semenchuk Yu. V. Smirenin A. A. Vorobyov N. I. Voropaev P. Wojciechowski J. Zmeskal 《Hyperfine Interactions》1993,82(1-4):273-293
The sticking process dt + n, which constitutes the most severe limit to the number of fusions which a muon can catalyze, is reviewed. Many attempts were made to determine by calculations and measurements the probability for initial sticking
s
0
(immediately after dt fusion) and for final sticking
s (after the came to rest). Previous results based on neutron disappearance rates and on the observation of -X-rays were controversial and also in some disagreement with theory. New data are reported from PSI on direct observation of final sticking, using a setup with the St. Petersburg ionization chamber. These data mark a significant improvement in reliability and may clarify questions concerning previous discrepancies. The new results is
s(0.56±0.04)%, lower than the theory prediction
s=(0.65±0.03)%, at medium density. 相似文献
33.
Synthetically Tuning the 2‐Position of Halogenated Quinolines: Optimizing Antibacterial and Biofilm Eradication Activities via Alkylation and Reductive Amination Pathways
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Akash Basak Yasmeen Abouelhassan Verrill M. Norwood IV Dr. Fang Bai Minh Thu Nguyen Prof. Shouguang Jin Prof. Robert W. Huigens III 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(27):9181-9189
Agents capable of eradicating bacterial biofilms are of great importance to human health as biofilm‐associated infections are tolerant to our current antibiotic therapies. We have recently discovered that halogenated quinoline (HQ) small molecules are: 1) capable of eradicating methicillin‐resistant Staphylococcus aureus (MRSA), methicillin‐resistant Staphylococcus epidermidis (MRSE) and vancomycin‐resistant Enterococcus faecium (VRE) biofilms, and 2) synthetic tuning of the 2‐position of the HQ scaffold has a significant impact on antibacterial and antibiofilm activities. Here, we report the chemical synthesis and biological evaluation of 39 HQ analogues that have a high degree of structural diversity at the 2‐position. We identified diverse analogues that are alkylated and aminated at the 2‐position of the HQ scaffold and demonstrate potent antibacterial (MIC≤0.39 μm ) and biofilm eradication (MBEC 1.0–93.8 μm ) activities against drug‐resistant Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecium strains while demonstrating <5 % haemolysis activity against human red blood cells (RBCs) at 200 μm . In addition, these HQs demonstrated low cytotoxicity against HeLa cells. Halogenated quinolines are a promising class of antibiofilm agents against Gram‐positive pathogens that could lead to useful treatments against persistent bacterial infections. 相似文献
34.
John S. Caughman IV 《Journal of Algebraic Combinatorics》2002,15(3):223-229
Let denote a bipartite distance-regular graph with diameter D 3 and valency k 3. Suppose 0, 1, ...,
D
is a Q-polynomial ordering of the eigenvalues of . This sequence is known to satisfy the recurrence
i – 1 –
i
+
i + 1 = 0 (0 > i > D), for some real scalar . Let q denote a complex scalar such that q + q
–1 = . Bannai and Ito have conjectured that q is real if the diameter D is sufficiently large.We settle this conjecture in the bipartite case by showing that q is real if the diameter D 4. Moreover, if D = 3, then q is not real if and only if 1 is the second largest eigenvalue and the pair (, k) is one of the following: (1, 3), (1, 4), (1, 5), (1, 6), (2, 4), or (2, 5). We observe that each of these pairs has a unique realization by a known bipartite distance-regular graph of diameter 3. 相似文献
35.
William F. Doran IV 《Journal of Algebraic Combinatorics》1998,8(3):253-272
This paper gives a new formula for the plethysm of power-sum symmetric functions and Schur symmetric functions with one part. The form of the main result is that for b,
where the sum is over semistandard tableaux T of weight a
b
,
is a root of unity, and maj(T) is a major index like statistic on semistandard tableaux.An Sb-representation, denoted S,b, is defined. In the special case when b, S,b is the Specht module corresponding to . It is shown that the character of S,b on elements of cycle type is
where the sum is over semistandard tableaux T of shape and weight ab. Moreover, the eigenvalues of the action of an element of cycle type acting on S,b are {
}. This generalizes J. Stembridge's result [11] on the eigenvalues of elements of the symmetric group acting on the Specht modules. 相似文献
36.
Albuquerque IF Bondar NF Carrigan R Chen D Cooper PS Dai Lisheng Denisov AS Dobrovolsky AV Dubbs T Endler AM Escobar CO Foucher M Golovtsov VL Gottschalk H Gouffon P Grachev VT Khanzadeev AV Kubantsev MA Kuropatkin NP Lach J Lang Pengfei Li Chengze Li Yunshan Luksys M Mahon JR McCliment E Morelos A Newsom C Maia MC Samsonov VM Schegelsky VA Shi Huanzhang Smith VJ Tang Fukun Terentyev NK Timm S Tkatch II Uvarov LN Vorobyov AA Yan Jie Zhao Wenheng Zheng Shuchen Zhong Yuanyuan 《Physical review D: Particles and fields》1994,50(1):R18-R20
37.
38.
Richard P. Kent IV 《Proceedings of the American Mathematical Society》2005,133(12):3735-3744
Given a compact orientable -manifold whose boundary is a hyperbolic surface and a simple closed curve in its boundary, every knot in is homotopic to one whose complement admits a complete hyperbolic structure with totally geodesic boundary in which the geodesic representative of is as small as you like.
39.
G.D. Alkhazov S.L. Belostotsky O.A. Domchenkov Yu.V. Dotsenko N.P. Kuropatkin M.A. Schuvaev A.A. Vorobyov 《Physics letters. [Part B]》1975,57(1):47-50
Differential cross sections for 1 GeV proton elastic scattering from 40,48Ca and 32,34S have been measured. The parameters of the nucleon distributions were obtained from an analysis of the experimental data. The difference between the neutron distributions in 40Ca and 48Ca is discussed in particular. 相似文献
40.
P. Egelhof G.D. Alkhazov M.N. Andronenko A. Bauchet A.V. Dobrovolsky S. Fritz G.E. Gavrilov H. Geissel C. Gross A.V. Khanzadeev G.A. Korolev G. Kraus A.A. Lobodenko G. Münzenberg M. Mutterer S.R. Neumaier T. Schäfer C. Scheidenberger D.M. Seliverstov N.A. Timofeev A.A. Vorobyov V.I. Yatsoura 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):27-33
Proton-nucleus elastic scattering at intermediate energies, a well-established method for probing nuclear-matter density distributions
of stable nuclei, was applied for the first time to exotic nuclei. This method is demonstrated to be an effective means for
obtaining accurate and detailed information on the size and radial shape of halo nuclei. Absolute differential cross-sections
for small-angle scattering were measured at energies near 700 MeV/u for the neutron-rich helium isotopes 6He and 8He, and more recently for the lithium isotopes 6Li, 8Li, 9Li and 11Li, using He and Li beams provided by the fragment separator FRS at GSI Darmstadt. Experiments were performed in inverse kinematics
using the hydrogen-filled ionization chamber IKAR which served simultaneously as target and recoil-proton detector. For deducing
nuclear-matter distributions, differential cross-sections calculated with the aid of the Glauber multiple-scattering theory,
using various parametrizations for the nucleon density distributions as input, were fitted to the experimental cross-sections.
The results on nuclear-matter radii and matter distributions are presented, and the significance of the data for a halo structure
is discussed. Nuclear-matter distributions obtained for 6He and 8He conform with the concept that both nuclei compose of α-particle like cores and significant neutron halos. The matter distribution
in 11Li exhibits, as expected from previous reaction cross-section studies with nuclear targets, the by far most extended halo
component of all nuclei being investigated. In addition the present data allow a quantitative comparison of the structure
of the He and Li isobares of either the mass number A = 6 or A = 8. The measured differential cross-sections have also been used for probing density distributions as predicted from various
microscopic calculations. A few examples are presented.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: p.egelhof@gsi.de 相似文献