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11.
J. Hladký M. Novák A. Prokeš J. Votruba V. I. Genchev V. D. Kekelidze V. G. Krivokhizhin V. V. Kukhtin M. F. Likhachev I. Manno I. A. Savin L. V. Silvestrov G. Vesztergombi K. -F. Albrecht A. Meyer H. -E. Ryseck M. Sachwitz F. Deak 《Czechoslovak Journal of Physics》1976,26(11):1290-1293
New experimental results on the coherentK
L
0
C K
S
0
C regeneration in the momentum range 10p30 GeV/c are presented. For the quantity (f
0–¯f
0/k (where f0 and¯f
0 are theKC and¯K
0C forward scattering amplitudes andk is the wave number) we have obtained: arg (f
0–¯f
0)/k=–126±14 and ¦(f
0–¯f
0/k¦ p
–0.62±0.14 These results are well described by a simple Regge pole model including only the (-trajectory exchange in thet-channel with the intercept (0) close to 0.4.Presented at the IV International Symposium on High Energy and Elementary Particle Physics, Warszaw, September 1975. 相似文献
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Laser ablation generation of clusters from As‐Te mixtures,As‐Te glass nano‐layers and from Au‐As‐Te nano‐composites. Quadrupole ion trap time‐of‐flight mass spectrometry
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15.
Lothar Heinrich Michaela Prokešová 《Methodology and Computing in Applied Probability》2010,12(3):451-471
We investigate a class of kernel estimators $\widehat{\sigma}^2_n$ of the asymptotic variance σ 2 of a d-dimensional stationary point process $\Psi = \sum_{i\ge 1}\delta_{X_i}$ which can be observed in a cubic sampling window $W_n = [-n,n]^d\,$ . σ 2 is defined by the asymptotic relation $Var(\Psi(W_n)) \sim \sigma^2 \,(2n)^d$ (as n →? ∞) and its existence is guaranteed whenever the corresponding reduced covariance measure $\gamma^{(2)}_{red}(\cdot)$ has finite total variation. Depending on the rate of decay (polynomially or exponentially) of the total variation of $\gamma^{(2)}_{red}(\cdot)$ outside of an expanding ball centered at the origin, we determine optimal bandwidths b n (up to a constant) minimizing the mean squared error of $\widehat{\sigma}^2_n$ . The case when $\gamma^{(2)}_{red}(\cdot)$ has bounded support is of particular interest. Further we suggest an isotropised estimator $\widetilde{\sigma}^2_n$ suitable for motion-invariant point processes and compare its properties with $\widehat{\sigma}^2_n$ . Our theoretical results are illustrated and supported by a simulation study which compares the (relative) mean squared errors of $\widehat{\sigma}^2_n$ for planar Poisson, Poisson cluster, and hard-core point processes and for various values of n b n . 相似文献
16.
Green polyaniline microparticles of variable density were prepared by the dispersion polymerization of aniline in the presence
of a mixture of steric stabilizers. A water-soluble polymer stabilizer, polyacrylamide, and a particulate one, colloidal silica,
were jointly used for this purpose. Silica was preferentially incorporated into the dispersion particles. The size of the
particles was determined by dynamic light scattering. The colour of the polyaniline colloids was characterized by the absorption
spectra. The density of the particles increased with increasing silica content, while the conductivity of the composites prepared
from dispersions was reduced at the same time.
Received: 19 November 1999/Accepted: 15 February 2000 相似文献
17.
V. Sechovský O. Syshchenko K. Prokeš A.V. Andreev M.I. Bartachevich T. Goto Y. Homma Y. Shiokawa 《Czechoslovak Journal of Physics》2002,52(2):271-274
We present a comparative study of magnetism in UCoAl and UNi2/3Rh1/3Al single crystals. UCoAl is commonly believed to be an itinerant 5 f-electron metamagnet with B
c < 1 T with uniaxial anisotropy. Pressure and alloying effects on the ground state point to competing ferromagnetic and antiferromagnetic interactions to be responsible for the non-magnetic ground state. UNi2/3Rh1/3Al is a solid solution between an antiferromagnet (UNiAl) and a ferromagnet (URhAl) and may have a similar underlying microscopic mechanism of the non-magnetic ground state. Possible analogies between the two compounds are discussed. 相似文献
18.
Laser Ablation Synthesis of Gold Selenides by using a Mass Spectrometer as a Synthesizer: Laser Desorption Ionization Time‐of‐Flight Mass Spectrometry
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Dr. Lubomír Prokeš Prof. Pavel Kubáček Prof. Eladia Maria Peña‐Méndez Dr. Filippo Amato Prof. José Elias Conde Dr. Milan Alberti Prof. Josef Havel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11261-11268
Methods for the rapid construction of new chemical motifs have the potential to accelerate the development of nanoscience. The synthesis of new chemical entities by laser ablation has been systematically demonstrated by using mixtures of gold and selenium. The compounds generated are detected by time‐of‐flight mass spectrometry and, for selected compounds, the structure is investigated by using density functional theory optimization. In total, 67 new gold selenide clusters have been synthesized, demonstrating an unsuspected richness in gold chemistry. Chemical species generated in the gas phase might inspire new routes for the synthesis of novel compounds in the solid state. 相似文献
19.
Effect of oxidant on electronic transport in polypyrrole nanotubes synthesized in the presence of methyl orange
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Martin Varga Jitka Kopecká Zuzana Morávková Ivo Křivka Miroslava Trchová Jaroslav Stejskal Jan Prokeš 《Journal of Polymer Science.Polymer Physics》2015,53(16):1147-1159
Polypyrrole nanotubes with diameter 60–400 nm are synthesized with methyl orange as template and various oxidants, iron(III) chloride hexahydrate, iron(III) sulfate hydrate, and ammonium peroxydisulfate. The highest electrical conductivity of compressed pellets, 66 S cm?1, is found for iron(III) chloride. Regions with 3D variable range hopping in series with ordered regions near metal–insulator transition govern the charge transport. Other oxidants and globular morphology provide less conducting samples, <10 S cm?1. The transport mechanism is identified with the heterogeneous model of tunneling between (bi)polaronic clusters with parallel contribution of Arrhenius‐like activated conductivity. The results of conductivity are correlated with the protonation level reflected in the infrared spectra and with the ratio of bipolaron/polaron bands revealed by Raman spectroscopy. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1147–1159 相似文献
20.