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1.
2.
It is long known that the Fokker-Planck equation with prescribed constant coefficients of diffusion and linear friction describes
the ensemble average of the stochastic evolutions in velocity space of a Brownian test particle immersed in a heat bath of
fixed temperature. Apparently, it is not so well known that the same partial differential equation, but now with constant
coefficients which are functionals of the solution itself rather than being prescribed, describes the kinetic evolution (in
the N→∞ limit) of an
isolated
N-particle system with certain stochastic interactions. Here we discuss in detail this recently discovered interpretation.
An erratum to this article can be found at 相似文献
3.
Bajdik J. Pintye-Hódi K. Novák Cs. Kelemen A. Regdon G. Erős I. 《Journal of Thermal Analysis and Calorimetry》2002,68(2):613-627
The extents of the protective effects of coating films on the surface of crystals were determined. Three different samples
were made with different quantities of coating fluid (Sepifilm LP 010 in 10% aqueous solution). Since the atomizing rate was
constant, the coating time increased in parallel with the volume of coating fluid applied. The direct measurement of film
thickness and smoothness is very difficult, and therefore indirect methods were used. Dimenhydrinate was chosen as model drug;
this is a heat-sensitive antihistamine with a low melting point. This temperature can be reached during the tableting process.
The behaviour of samples on exposure to heat was examined by differential scanning calorimetry. The water uptakes of the samples
were determined with an Enslin apparatus. Plasticity was studied with an instrumented tablet machine. These indirect methods
(thermal conductivity, water uptake and plasticity measurements) revealed connections between the results of the various experiments.
An overlong coating time decreased the protective effect of the coating film.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
4.
Guido Wauters Jacques Dewaele Carlo Vandecasteele Richard Dams 《Mikrochimica acta》1989,98(4-6):157-162
Proton activation analysis was used for the determination of cadmium and lead in three sediment reference materials. The method is based on the111,112Cd(p, xn)111 In and the206,207,208Pb(p, xn)206Bi reactions.111In and206Bi were chemically separated by anion exchange. The results obtained were taken into account for the certification of the materials and are in the excellent agreement with the certified values. 相似文献
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6.
R. Pizzoferrato L. Lagonigro T. Ziller A. Di Carlo R. Paolesse F. Mandoj A. Ricci C. Lo Sterzo 《Chemical physics》2004,300(1-3):217-225
We study the infrared emission at 1.54 μm of an organolanthanide complex, Er(III)-tetraphenylporphyrin [Er(TPP)acac], both as a result of direct optical excitation and via energy transfer from host π-conjugate polymers of type poly(arylene–ethynylene) [PAE]. In the first case, the emission of the neat complex is characterized in inert transparent materials and a value of the quantum yield at 1.54 μm φIR=4×10−4 is measured. Then, fluorescence resonance transfer is investigated in blends of Er(TPP)acac with PAEs by monitoring the quenching of the polymer fluorescence along with the enhancement of both the visible emission of the ligand and the near-infrared band of Er3+. These different procedures allow a detailed analysis of the transfer efficiency within a specific implementation of the Förster model for polymeric donors. The experimental values of the critical radius R0, ranging from 1.3 to 2.5 nm for the different blends, are in good agreement with theory for a wide interval of the physical and spectroscopic parameters. This suggests that other mechanisms for excitation transfer do not play a significant role in these materials. 相似文献
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Peptidic aminopeptidase inhibitors, bestatin, phebestin and probestin have been prepared by stereo- and regiocontrolled reactions from a common α,β-epoxy ester precursor. 相似文献
10.