Solution of the Królikowski-Rzewuski equation for distinguished component of a state-vector describing an unstable system

Equation for distinguished component of a state-vector describing unstable system is solved by means of iterative procedure. Zeroth order of approximation yields the probability amplitude for surviving a given state up to some time t.     

s-channel discontinuities of reggeon diagrams with planar vertices

The mutual relations between s-channel discontinuities of reggeon diagrams with planar triple-Regge vertices are discussed. It is shown that, in general, contributions coming from different cuttings are not simply related to each other as certain vertices acquire non-trivial phase factors depending on the nature of the cutting. For diagrams with only triple-Regge vertices this phase may be related to the triple-Regge phase. The complete four-reggeon vertices are not known in general. An approximation is considered which amounts to preserving only the absorptive part of triple- or four-reggeon amplitudes in certain parts of the diagrams. This approximation turns out to be equivalent to a simple absorbed multiperipheral model. The problem of exchange degeneracy breaking within the dual unitarisation Scheme is briefly discussed as an example.     

Thiomercurimetric determination of carbon disulphide, carbonyl sulphide, thiols and hydrogen sulphide by use of 1,3-diaminopropane and tributyltin chloride

A new approach to the determination of carbon disulphide and carbonyl sulphide in the presence of each other is based on the reaction with 1,3-diaminopropane (DAP), and titration with o-hydroxymercurybenzoie acid (HMB) before and after the selective decomposition of the COS-derivative at pH 4. Determination of hydrogen sulphide, thiols, carbon disulphide and carbonyl sulphide in the presence of each other in hydrocarbon solvents involves four titrations with HMB, viz. of all compounds after conversion of CS(2) and COS with DAP, of thiols plus H(2)S, of the thiols alone after removal of H(2)S by extraction, and of CS(2) alone after removal of other compounds by shaking with aqueous alkali. For selective trapping of H(2)S, HCN, RSH, CO(2) and CS(2) + COS, the sample gas is passed successively through a potassium antimonyl tartrate filter, a nickel carbonate filter, a tributyltin chloride filter, a bubbler containing 40% potassium hydroxide solution and a bubbler containing a benzene solution of DAP. The analysis is completed by titration with HMB with dithizone or dithiofluorescein as indicator.     

Simple methods for dead-time and pile-up corrections in analytical gamma-ray spectrometry

In the paper the mathematical methods for dead-time and pile-up corrections are discussed. The dead-time correction formulae for a system of two short-lived isotopes and constant component (background) are reported which mathematical problem has not been solved so far. The new electronic circuit for simultaneous measurements of clock- and live- (or dead-) times is described. It is shown that using this circuit one can correct the counting loss for both effects simultaneously. Finally, the advantages and disadvantages of mathematical methods for dead-time and pile-up corrections are discussed based on the authors' several-year laboratory practice.     

The limiting nuclear target fragmentation and the thermodynamical model

The fragmentation of nuclear targets is considered in the frame of the thermodynamical model. The scaling properties of experimental data concerning backward particles are described.     

High efficient system for studying multiphoton absorption

An optical arrangement for studying two-photon absorption in liquids is presented. The main feature of this new arrangement is fuller utilization of fluorescence light. This makes possible application of very low power cw laser in such experiments.     

Diffraction of light by adjacent fundamental and second or fourth harmonic ultrasound beams: Comparison of exact and simplified formulae with experiment

Theoretical expressions and their approximate formulae for the intensities of light diffracted by two adjacent ultrasonic beams are discussed and compared with experimental data for the case when the second beam is an even harmonic of the first (fundamental). In the special case of the fundamental and its second or fourth harmonic, relatively simple formulae are found for the first and second diffraction orders describing the variation of light intensity with phase shift and intensity ratio.The approximate formulae describe the experiments satisfactorily only for small values of ζ₁ and α_n. For higher values the exact formulae give better agreement. Only the Raman-Nath region is considered.     

Summation to infinity of the virial expansions for two-dimensional systems

A new physical relationship, the Two-Dimensional Unit Compressibility Law, is postulated, and verified by using theoretical, two-dimensional virial coefficients. According to this law, under conditions when the two-dimensional compressibility factor is equal to unity, the density of the two-dimensional mobile phase is a linear function of the absolute temperature. This relationship makes the summation possible, of the virial expansion for the spreading factor.     

Optimum Q-value in multinucleon transfer reactions

The kinematics of multinucleon transfer reactions are examined under the assumption that the optimum Q-value is equal to the sum of the separation energies of the transferred nucleons. Very good agreement with experimental data is obtained.