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941.
YoungJu Choie Olav K. Richter 《Proceedings of the American Mathematical Society》2007,135(8):2309-2315
We determine a class of functions spanned by theta series of higher degree. We give two applications: A simple proof of the inversion formula of such theta series and a classification of skew-holomorphic Jacobi forms.
942.
B. D. Kabulov K. A. Akhundzhanov F. U. Yunusov O. A. Shpigun S. S. Negmatov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2007,81(3):354-356
The hydrolytic polycondensation of tetraethoxysilane in the presence of various polymers (polyacrylonitrile, polycaproamide, and chitosan) as templates was performed with the use of the sol-gel technology to obtain nanohybrid composite polymer-silica sorbents-nanofractals. 相似文献
943.
944.
In recent years there has emerged significant interest in low pressure radio frequency (rf) glow discharges which are used widely particulary in IC fabrication. Various parameters of the rf glow discharge have been found to be useful for its electrical characterization; however, there is no uniformity and agreement. Extensive experimental investigations on various discharge systems have shown, that the self-bias on the rf driven electrode, the complex conductivity and the breakdown characteristic are preferable parameters of rf discharges. Advantageously the self-bias and the complex conductivity should be presented in dependence on the pressure and the applied rf voltage. The discharge current cannot be measured quite accurately due to currents via leaky capacitors and the deviations from a sinusoidal form of the current due to nonlinearities. 相似文献
945.
Consider the problem of three point vortices (also called Helmholtz’ vortices) on a plane, with arbitrarily given vorticities.
The interaction between vortices is proportional to 1/r, where r is the distance between two vortices. The problem has 2 equilateral and at most 3 collinear normalized relative equilibria.
This 3 is the optimal upper bound. Our main result is that the above standard statements remain unchanged if we consider an
interaction proportional to r
b, for any b < 0. For 0 < b < 1, the optimal upper bound becomes 5. For positive vorticities and any b < 1, there are exactly 3 collinear normalized relative equilibria. The case b = −2 of this last statement is the well-known theorem due to Euler: in the Newtonian 3-body problem, for any choice of the
3 masses, there are 3 Euler configurations (also known as the 3 Euler points). These small upper bounds strengthen the belief
of Kushnirenko and Khovanskii [18]: real varieties defined by simple systems should have a simple topology. We indicate some
hard conjectures about the configurations of relative equilibrium and suggest they could be attacked within the quasi-polynomial
framework. 相似文献
946.
J.T. Elizalde Galindo A.H. Adair C.E. Botez V. Corral Flores D. Bueno Baques L. Fuentes Cobas J.A. Matutes-Aquino 《Applied Physics A: Materials Science & Processing》2007,87(4):743-747
Measurements of ac-susceptibility and dc-magnetization were carried out on samples of Ni1-xZnxFe2O4 nanoparticles (x=0, 0.25, 0.5, 0.75) with average diameters 〈D〉≈7 nm. Values of the superparamagnetic blocking temperature
T̄B were obtained from the characteristic temperature behavior of the imaginary susceptibility χimag. An Arrhenius-type law, which accurately describes the relationship between the observation time τobs and the blocking temperature, was used to determine the effective energy barrier to magnetization reversal Ueff. A Zn-content dependence of the energy barrier is observed, where Ueff changes little for 0≤x≤0.25, it peaks at x=0.5, and decreases back upon further Zn-doping. The large increase of Ueff at x=0.5 is attributed to an enhanced magnetic anisotropy induced by the crossover between two spatial arrangements of spins
in the A and B sub-lattices of the ferrimagnetic inverse spinel.
PACS 75.50.Bb; 75.50.Gg; 75.30.Et 相似文献
947.
D.L. Mills 《Applied Physics A: Materials Science & Processing》2007,87(3):427-431
This paper begins with some historical remarks regarding the author’s early interest in the use of electron energy loss spectroscopy
to probe dynamical phenomena on crystal surfaces. We then discuss the physical nature of the interactions responsible for
vibrational and spin waves losses, with attention to their role in related phenomena.
PACS 61.14.-x; 68.35.Ja; 68.49.Jk; 68.49.Uv 相似文献
948.
Y.-Q. Peng J.-H. Yang F.-P. Lu Q.-S. Yang H.-W. Xing X.-S. Li C.-A. Song 《Applied Physics A: Materials Science & Processing》2007,86(2):225-229
Based on the assumption of Gaussian energy distributions of the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO), analytical expressions of generalized Einstein relation in chemically doped organic semiconductor are developed, by approximation of Coulomb traps with a rectangle potential well. Numerical calculations show that traditional Einstein relations do not hold for chemically doped organic semiconductors. Similar to physical doping, the dependence of diffusion coefficient to mobility D/μ ratio on the carrier concentration has a maximum. An essential difference between chemical doping and physical doping is that, the D/μ ratio in chemically doped organic semiconductors depends not only on carrier concentration and doping concentration, but also on the applied electric field. PACS 71.20.Rv; 72.90.+y; 73.50.-h 相似文献
949.
Within the perturbative-recombination model, the charge asymmetries in the D* +–D* ?, D* 0–D* 0, and D + s –D ? s yields are estimated under the kinematical conditions of the COMPASS experiment. Corrections that arise owing to the mass of a light quark in a charmed meson are taken into account. The yield of D + s meaons is predicted to be large in relation to the yield of D ? s mesons. 相似文献
950.
Yu. A. Shishov 《Physics of Particles and Nuclei》2006,37(3):444-473
This is a retrospective review of superconducting magnets for spectrometers of high-energy particles. The magnets are grouped according to the purpose of the spectrometers and the shape of coils. Data on the thermostatting and electrical protection of the coils are presented. Design features of various-type magnets are described. The first large superconducting solenoids were constructed for hydrogen bubble chambers. Further progress was related to the construction of spectrometers that were designed for experiments at colliders and included solenoids with radiation-transparent walls. Along with solenoids, dipole and toroidal magnets were used in spectrometers; some designs of such magnets are also discussed in the review. A special type of polarizing solenoid is used in polarized targets. Spectrometers with magnets of various coil shapes were created for astrophysical research. As an instance, the original radiation-transparent solenoid and the dipole magnet with a cryocooler are represented. Prospects for the future development of magnets are connected with the use of high-temperature superconductors (HTS). Information on the present situation in engineering the HTS ribbon and solenoids is given. 相似文献