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91.
92.
Paramagnetic pyrroline and 1,2,3,6-tetrahydropyridine derivatives of BODIPY and their diamagnetic analogs have been synthesized and characterized as novel redox double sensor and cation sensitive reagents. 相似文献
93.
94.
In this paper, space adaptivity is introduced to control the error in the numerical solution of hyperbolic systems of conservation laws. The reference numerical scheme is a new version of the discontinuous Galerkin method, which uses an implicit diffusive term in the direction of the streamlines, for stability purposes. The decision whether to refine or to unrefine the grid in a certain location is taken according to the magnitude of wavelet coefficients, which are indicators of local smoothness of the numerical solution. Numerical solutions of the nonlinear Euler equations illustrate the efficiency of the method. 相似文献
95.
V. Petržílka 《Czechoslovak Journal of Physics》1997,47(2):183-196
Test particle motion and acceleration has been explored in strong radio frequency (RF) fields, for which quasilinear ponderomotive force approximation is not valid. By nonlinear acceleration in spatially varying wave amplitude of RF travelling wave, electrons may be accelerated to time averaged velocities significantly larger than the RF wave phase velocity, and than the boundary plasma thermal velocity, in RF fields of several Volts per centimeter at wave frequency of 7 MHz. It is also demonstrated that even weak spatial gradients, much weaker than those expected in experiments, of the RF wave field amplitude, have significant consequences for the particle motion. Estimates are presented of the total energy transferred from the near antenna RF field to the plasma due to the nonlinear electron acceleration effects. 相似文献
96.
We study condensation of ethanol-hexanol vapour by numerical solution of kinetic equations. The number of droplets formed
in unit volume is computed within self-consistent classical model. It is shown that formation of ethanol-rich droplets prevails
at the initial stage of nucleation process, but in the stationary state formation of droplets near the saddle point (on cluster
formation energy surface) plays the dominant role.
Presented at the 6th Joint Seminar “Development of Materials Science in Research and Education”, Karlštejn, Czech Republic,
17–19 September 1996.
This work was supported by Grant No. A1010615 of the Grant Agency of the Academy of Sciences of the Czech Republic. 相似文献
97.
S. Pumplün 《manuscripta mathematica》1998,97(1):93-108
For a Brauer–Severi variety X over a field k of characteristic not two, every symmetric bilinear space over X up to Witt equivalence is defined over k.
Received: 2 February 1998 相似文献
98.
P. González D. Fernández J. Pou E. García J. Serra B. León M. Pérez-Amor T. Szörényi 《Applied Physics A: Materials Science & Processing》1993,57(2):181-185
A study of the gas-phase parameters involved in ArF laser induced chemical vapour deposition of silicon-oxide thin films is presented. A complete set of experiments has been performed showing the influence of the concentration of the precursor gases, N2O and SiH4, and their influence on total and partial pressures on film growth and properties. In this paper we demonstrate the ability of this LCVD method to deposit silicon oxide films of different compositions and densities by appropriate control of gas composition and total pressure. Moreover, a material specific calibration plot comprising data obtained using different preparation techniques is presented, allowing determination of the stoichiometry of SiO
x
films by using FTIR spectroscopy independently of the deposition method. For the range of processing conditions examined, the experimental results suggest that chemical processes governing deposition take place mainly in the gas phase. 相似文献
99.
Impact of the internucleotide linkage modification by inserting a methylene group to the P-O bond (—O—PO
2
—
—O— chain changed for —O—PO
2
—
—CH2—O—), on the modified oligonucleotide binding ability to the natural DNA strand was studied by molecular dynamics simulation. Complex of (dT)11 with a deoxyadenosine undecamer containing alternating modified and natural internucleotide linkage was studied as a model system. The Amber force field was completed by a set of new parameters needed to model the modified part of the nucleotide. The simulations confirmed existence of a double-helical complex the melting point of which is considerably higher than 300 K. While the thymidine (unmodified) strand possesses a B-type secondary structure, the conformation of the adenosine (modified) strand is not stable at 300 K. The -ggt conformation of the modified linkages is highly preferred, temporary jumps to the -g-gt and ggt conformations were, however, observed. 相似文献
100.
V.I. Fernández A. Iucci C.M. Naón 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,30(1):53-56
We present an extension of the Tomonaga-Luttinger model in which left and right-moving particles have different Fermi velocities.
We derive expressions for one-particle Green's functions, momentum-distributions, density of states, charge compressibility
and conductivity as functions of both the velocity difference ε and the strength of the interaction β. This allows us to identify
a novel restricted region in the parameter space in which the system keeps the main features of a Luttinger liquid but with
an unusual behavior of the density of states and the static charge compressibility κ. In particular κ diverges on the boundary
of the restricted region, indicating the occurrence of a phase transition.
Received 20 May 2002 / Received in final form 23 August 2002 Published online 19 November 2002 相似文献