Please forward books for review to the Book Review Editor: Magdolna Hargittai, Structural Chemistry Research Group of the Hungarian Academy of Sciences, Eötvös University, H-1431 Budapest, Pf. 117, Hungary. 相似文献
Electrical conductivity and fundamental absorption spectra of monocrystalline Cu7GeS5I were measured in the temperature ranges 95-370 and 77-373 K, respectively. A rather high electrical conductivity (σt=6.98×10−3Ω−1 cm−1 at 300 K) and low activation energy (ΔEa=0.183 eV) was found. The influence of different types of disordering on the Urbach absorption edge and electron-phonon interaction parameters were calculated, discussed and compared with the same parameters in Cu7GeS5I, Cu6PX5I (X=S,Se) and Ag7GeX5I (X=S,Se) compounds. We have concluded that the P→Ge and Cu→Ag cation substitution results in an increase of the electrical conductivity and a decrease of the activation energy. Besides, P→Ge substitution, results in complete smearing and disappearance of the exciton absorption bands and in blue shift of the Urbach absorption edge, an increase of the edge energy width and an electron-phonon-interaction enhancement. 相似文献
We analyze relations between various forms of energies (reciprocal capacities), the transfinite diameter, various Chebyshev
constants and the so-called rendezvous or average number. The latter is originally defined for compact connected metric spaces
(X,d) as the (in this case unique) nonnegative real number r with the property that for arbitrary finite point systems {x1, …, xn} ⊂ X, there exists some point x ∈ X with the average of the distances d(x,xj) being exactly r. Existence of such a miraculous number has fascinated many people; its normalized version was even named “the magic number”
of the metric space. Exploring related notions of general potential theory, as set up, e.g., in the fundamental works of Fuglede
and Ohtsuka, we present an alternative, potential theoretic approach to rendezvous numbers. 相似文献
A computer controlled automatic calibration apparatus for the dynamic generation of organic vapors was developed. A calibration loop was filled by diffusion with organic compounds and diluted using nitrogen as a carrier gas. The compound holder pipe was thermostated at 40°?C. Fittings were made of PTFE and the valves were constructed of stainless steel. Moisture interferences were reduced using a Nafion membrane filter. The vapor generator was validated by a gas chromatographic method. The measured and calculated values were compared and good correlation (r = 0.9903) was found. 相似文献
Summary We show that an existence and uniqueness and a comparison theorem hold if we add a space time white noise to a quasi-linear parabolic equation in one space dimension, even if the nonlinearity is only measurable and not even locally bounded.Research supported by the Hungarian National Foundation of Scientific Research No. 2290. Université de Provence (Aix-Marseille I), Mathématiques Case 64, Place Victor Hugo, 13331 Marseille, Cedex 3 (for the academic year 1991/92)Partially supported by DRET under contract 901636/A000/DS/SR 相似文献
Reaction of a series of P-amino and P-cycloalkoxy dibenzo[c.e][1,2]oxaphosphorines (1), (3) and (5) with cis-bis(benzonitrile)dichloroplatinum(II) afforded the title bis(dibenzooxaphosphorino) complexes (2), (4) and (6), respectively. In the case of chiral P-substituents, the complexes (4) and (6) were obtained in homo and heterochiral forms. Stereospecific 1J(195Pt–P) couplings found in the 31P-n.m.r. spectra of the products (2), (4) and (6) suggested the cis orientation of the identical substituents. 相似文献
In this work potato genotypes originated from an intensive resistance breeding programme that includes unique combination of resistance to several pathogens and consumer response were analysed for glycoalcaloid content by reversed phase high performance liquid chromatographic method. The glycoalcaloids were concentrated from potato samples by solid-phase extraction with a disposable C18 cartridge column. Nucleosil 100-5 C-18-AB column was used with 50% acetonitrile in phosphate buffer as the mobile phase. The method was validated according to calibration curve, precision and recovery tests, limit of detection and quantitation. The results indicated that as low as 0.27 µg mL−1 can be quantitatively determined by this method with 94–98% and 99% for recovery and precision, respectively. Hungarian potatoes were analysed by the adapted procedure for their glycoalcaloid content. The result showed that the tested Hungarian potato varieties contain glycoalcaloids between 0.09 and 15 mg 100 g−1. The content of glycoalcaloids in the new varieties of potato was lower than the limit of the Official Food Regulations.
Summary We prove an approximation theorem for stochastic differential equations, under rather weak smoothness conditions on the coefficients, when the driving semimartingales are approximated by continuous semimartingales, in probability, and the solutions are considered in several Banach spaces, defined in terms of different types of the modulus of continuity. Hence Stroock-Varadhan's support theorem is obtained in these spaces, in particular, in appropriate Besov and Hölder spaces.Partially supported by the Foundation of National Research n° 2290Partially supported by the DGICYT grant no PB 90-0452 相似文献