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61.
Synthesis of 1,3-Bis(trialkylammonio)-2-propanol Dihalides Exhibiting Retardant Activity toward Rape
Merkis A. I. Novickiene L. L. Daukšas V. K. Šaltite Z. A. Miliuviene L. I. Gaveliene V. A. 《Russian Journal of Applied Chemistry》2003,76(1):160-161
1,3-Bis(trialkylammonio)-2-propanol dihalides were prepared, and their retardant activity was studied in relation to the chemical structure. 相似文献
62.
R. Strašek 《Acta Mathematica Hungarica》2003,101(1-2):63-68
We consider the class of Euclidean algebras associated to Minkowski light cones and called Lorentz algebras. We prove that in Lorentz algebras the estimate ∥P(a,b) ∥∞≥(√2-1) ∥a∥∞ ∥b∥∞ is valid for the spectral norm and is therefore independent of the dimension of the Lorentz algebra. 相似文献
63.
64.
Miroslav Menšík 《Czechoslovak Journal of Physics》1998,48(4):469-475
A time solution of the excimer-ion pair system is presented here with a special attention to the time asymptote.
Presented at the Czech-Israeli-German Symposium “Dynamical Processes in Condensed Molecular Systems”, Prague, Czech Republic,
26–30 May 1997.
This work was supported by the grant No. C 1050601 of the Grant Agency of the Academy of Sciences of the Czech Republic. 相似文献
65.
Time-resolved pulsed spectroscopy was used to measure the luminescence spectra of calcium fluoride. Characteristic features
of the luminescence of self-trapped excitons are discussed. It is shown that various configurations of self-trapped excitons
incorporating hole nuclei of a more complex structure, may be formed in CaF2 crystals.
Fiz. Tverd. Tela (St. Petersburg) 40, 1226–1227 (July 1998) 相似文献
66.
A special two-sided condition for the incremental magnetic reluctivity is introduced which guarantees the unique existence of both the weak and the approximate solutions of the nonlinear stationary magnetic field distributed on a region composed of different media, as well as a certain estimate of the error between the two solutions. The condition, being discussed from the physical as well as the mathematical point of view, can be easily verified and is fulfilled for various magnetic reluctivity models used in electrotechnical practice. 相似文献
67.
The antioxidative effect of two non-steroidal anti-inflammatory drugs was studied in vitro by measuring the kinetics of degradation of high-molecular weight hyaluronan (HA) in a system comprising hypochlorous acid + CuCl2 + ascorbic acid using a Brookfield rotational viscometer equipped with a Teflon cup and spindle of coaxial cylindrical geometry. The changes in HA chemical structure were investigated by chemiluminometry. When sodium naproxen was added to the system during a running degradative process its inhibitory effect was clearly shown. The inhibition was dependent on the drug concentration. However, when this drug was added to the system before the initiation of HA degradation, no inhibition was seen even at the highest drug concentration tested. The inhibitory effect of acetylsalicylic acid was achieved with a relatively low concentration of the drug and was independent of the experimental model used. 相似文献
68.
Jozef Bicerano 《Journal of Polymer Science.Polymer Physics》1991,29(11):1329-1343
A new model for the dynamic relaxations occurring below the glass transition temperature in amorphous polymers is introduced. This model combines ideas from theoretical solidstate physics, thermodynamics, and statistical mechanics. Formal analogies are made between the dynamic relaxations and phase transitions. The concepts of percolation theory are briefly discussed. The molecular level motions which might be giving rise to each dynamic relaxation are incorporated within this framework. The simplest version of the model is then formally implemented within the context of bisphenol-A polycarbonate (BPAPC) and its poly (ester carbonates) (PEC). The following results are calculated: (1) Characteristic temperatures (Tc) for BPAPC, similar to γ1, and γ2 relaxation temperatures observed by dynamic mechanical spectroscopy (DMS) at commonly used measurement frequencies. (2) Tc for the β2 relaxation in tetrabromo-BPAPC much higher than the Tc in BPAPC. (3) A slow and monotonic increase in both the intensity and the Tcof the γ2 relaxation with an increasing fraction of terephthalate comonomer in PEC copolymers. It is hoped that this model, which is admittedly tentative at this time, will be useful as a working hypothesis. The next paper of this series will provide extensions and generalizations of the model, and its application to the poly (alkyl methacrylates). 相似文献
69.
A.V. Andreev B. Janoušová V. Sechovský Y. Homma Y. Shiokawa 《Czechoslovak Journal of Physics》2002,52(2):275-278
We present the first single-crystal study of Fe and Ni doped U(Co1-x
T
x
)Al compounds in comparison to the parent compound, the itinerant 5f-electron metamagnet UCoAl. Magnetization and specific-heat data measured in the temperature range of (1.8-300) K and in fields up to 10 T are analyzed and discussed. Both compounds exhibit a strong uniaxial anisotropy with the dominating magnetic response along the c-axis of the hexagonal ZrNiAl-type structure. Ni substitution yields an increase of the critical field for metamagnetism; UCo0.95Fe0.05Al is ferromagnetic below 30 K. Temperature evolution of the entropy change between 0 and 10 T points to involvement of magnetic correlations or spin fluctuations in the paramagnetic compounds UCoAl and UCo0.95Ni0.05Al. 相似文献
70.
I. M. Shmyt’ko A. N. Izotov N. S. Afonikova S. Vieira G. Rubio 《Physics of the Solid State》1998,40(4):687-690
The formation of polytypic modifications is observed in dislocation-free silicon single crystals under directional plastic
deformation. It is shown that the deformation-stimulated phase appears on the surface of the sample in the form of small grains
ranging from several hundred to several thousand angstroms in size. A twin structure in the individual grains is observed.
Fiz. Tverd. Tela (St. Petersburg) 40, 746–749 (April 1998) 相似文献