Determination of spherulite size distribution by small-angle light scattering

The theoretical backgrounds of the method of spherulite size distribution determination, on the basis of the small-angle light scattering technique, are presented. Special corrections of experimental data are introduced to achieve great accuracy of the determination of scattered light intensity distribution. Experiments have been done on low-density polyethylene samples obtained in various crystallization conditions. For these samples, the stepwise distributions of spherulite size have been determined.     

HYDRATED ELECTRON FORMATION IN NANOSECOND and PICOSECOND LASER FLASH PHOTOLYSIS OF HEMATOPORPHYRIN IN AQUEOUS SOLUTION

Nanosecond (lambda exc = 266, 355 and 532 nm) and picosecond (lambda exc = 355 nm) laser flash photolysis of hematoporphyrin (Hp) was performed in neutral (pH 7.4) and alkaline (pH 12) aqueous solution, as well as in the presence of 0.1% Triton X-100. The dependence of the yield of photoproduced hydrated electrons (e-aq) on laser pulse energy was studied over a wide range of energies (0.2 to greater than 1000 mJ cm-2). The results show that e-aq are predominantly formed in a two-photon process at lambda exc = 266 and 355 nm. One-photon quantum yields are higher at lambda exc = 266 nm than at lambda exc = 355 nm. Both one-photon and two-photon pathways are less efficient at higher Hp concentration, reflecting the influence of Hp self-aggregation. Two-photon e-aq formation is more efficient when 30 ps pulses are used for excitation, as compared to 10 ns pulses. No e-aq could be detected at lambda exc = 532 nm. Nanosecond pulse-induced transient spectra obtained at pH 7.4 are also discussed.     

Analysis of elastic scattering of 0.8 GeV polarized protons from 116Sn and 124Sn

Differential cross section and analyzing power data for elastic scattering of 0.8 GeV polarized protons from ¹¹⁶Sn and ¹²⁴Sn are analyzed in terms of a spin-dependent Kerman-McManus-Thaler formalism. Neutron matter densities and rms radii are deduced with careful attention to sources of error, and found to be in good agreement with Hartree-Fock predictions.     

TheA-scaling of the multiplicity distributions ofπ ′,K − and\bar P interactions with nuclei at 40 GeV/c

The multiplicity distributions of charged particles produced from π^?,K ^? and \(\bar p\) interactions with the nuclei Li, C, S, Cu, CsI, Pb at 40 GeV/c were studied. It was found that the linear relationD=a〈n〉+b is satisfied for the distributions of different kinds of secondary particles including knocked out protons. Consequently, the use of the scaling variablez′=(an+b)/(a〈n〉+b) ensures the scaling of the distributions with respect to the mass numberA at least up to the second moment.     

On c+-chromatic graphs with small bounded subgraphs

It is shown that if ZF is consistent then so is ZFC+2 is as large as you wish + there is a graph with cardinality and chromatic number (2) + such that every subgraph of cardinality 2 has chromatic number .The preparation of this paper was supported by Hungarian National Foundation for Scientific Research (OTKA), grant no. 1805.     

Neutral strange particle production in high transverse momentum π− nucleus interactions at ∼40 GeV/c

Measurements ofK _s ⁰ , Λ and \(\bar \Lambda \) production in π^? nucleus (C, Cu, Pb) interactions are presented. The experiment was carried out with the streamer chamber spectrometer RISK using a π^? beam of ～40 GeV/c and a trigger requiring a secondary charged particle with transverse momentum above 1.1 GeV/c. Production cross sections, relative production rates and distributions of Feynmanx and transverse momentum squared as well as correlations between theV ⁰ and the trigger particle are presented. The results are compared and found to be in agreement withK _s ⁰ , Λ and \(\bar \Lambda \) data from untriggered π^? p and π^? C interactions, except for the relative production rate of antilambdas which is about to times larger in high-p _t collisions. Our results can be well interpreted within the dual topological unitarization model.     

Fast degradation of fullerenes by ultraviolet laser radiation

The first observation of fullerene C₆₀ ultraviolet photolysis in hexane solution was published two years ago [1]. Similar further experiments realized with an ultraviolet lamp and solar light gave inconsistent results with ambiguous interpretations. We report the unexpectedly fast and efficient degradation of the fullerenes in n-hexane solutions, induced by an XeCl-excimer laser. Well-defined experimental conditions and good reproducibility in these experiments allow us to estimate the minimal value of the quantum yield of fullerene photolysis.     

Kinetik und Mechanismus des Ligandentausches zwischen Thallium(III)oxinat und Eisen(III) in Propylencarbonat

The transfer of oxinate ions from thallium (III)oxinate to trivalent Fe(DMF) ₆ ³⁺ in propylenecarbonate takes place via rearrangements within a rapidly formed binuclear thallium(III)—iron(III) complex. In a last rapid step this rearranged complex reacts with excess reactants to the final products whose composition accordingly depends on the ratio of the reactant concentrations.

     

Synthese von (+)-Abscisinsäure

Synthesis of (+)-Abscisic Acid . Starting from (4S)-4-hydroxy-2,6,6-trimethylcyclohex-2-enone ( 2 ), a short synthesis of the natural (+)-abscisic acid ((+)- 1 ) has been accomplished.