[en] Short communication. 3 refs., 1 fig

No abstract available

[en] In this paper, we investigate the generalized seniority scheme and the validity of Generalized Seniority Schmidt Model in and around the $Z=82$ semi-magic region. A consistently same multi-j configuration is used to explain all the nuclear spectroscopic properties such as g−factors, Q−moments and $B(E2)$ trends for the $13/2^{+}$, ${12}^{+}$ and $33/2^{+}$ isomers in all the three Hg, Pb and Po isotopic chains. The inverted parabolic $B(E2)$ trends for the first $2^{+}$ states in Hg, Pb and Po isotopes are also explained using the generalized seniority scheme. A comparison with the experimental data is presented, wherever possible, and future possibilities are suggested.

[en] New experimental results on photo-excitation of the Cd and In spin isomers by real and virtual photons (electrons) in the threshold energy region are presented. Measurements have been performed using the INR electron linac LUE—8 MeV and, in parallel, the femtosecond laser facility of the Moscow State University. A detailed description of experimental methods based on the GEANT-4 simulation is done. The obtained data are discussed in frame of the phenomenological model which allows the theoretical evaluation of the isomeric ratio in this energy region. Contribution of the dipole and quadrupole mode excitations in Cd and In nuclei from measurements with real and virtual photons is discussed. (paper)

[en] The analogy between the isomeric of molecules and the shape isomeric of nuclei is shown and the main features of the fission isomers as halflives, probabilities of spontaneous fission and spins are discussed. Possible explanation of the nature of fission isomers, based on the Strutinsky model, is given. Subsequently, systematics of the halflives of fission isomers and their dependence on the neutron number for U - Cm isomers and on Z²/A for odd-odd, odd-proton, odd-neutron and even-even isomers is shown. Quite new approach to the problem, which is made possible by the existence of negative muons is considered. For some heavy elements e.g. ²³⁹Pu 25% of 2P-IS transitions are not accompanied by X-ray emission but the total energy of 2P-IS orbit is transferred immediately into the nucleus, the latter being excited to 6.5 MeV. These radiationless transitions considered as transitions of negative muons can be accompanied by formation of fission isomers. The isomeric level in the presence of a muon is expected to be shifted and the halflife will be changed. It is concluded that the search for gamma decay of shape isomers is still one of the most important problems as well as the U search for the new region of shape isomeric which is predicted by the Strutinsky model. (S.B.)

[en] A ¹¹⁹Sn Moessbauer study was carried out of tin(IV) complexes with 2-benzoylpyridine thiosemicarbazone (H2Bz4DH) and its N(4)-methyl (H2Bz4M) and N(4)-phenyl (H2Bz4Ph) derivatives: [Sn(2Bz4DH)Cl₃] (1), [Sn(2Bz4DH)PhCl₂] (2), [Sn(2Bz4M)Cl₃] (3), [H₂2Bz4M]₂[Ph₂SnCl₄] (4), [Sn(2Bz4Ph)PhCl₂] (5), [Sn(2Bz4Ph)Ph₂Cl] (6), in which H2Bz4R stands for the neutral ligand and 2Bz4R stands for the anionic thiosemicarbazone. In addition, ¹¹⁹Sn Moessbauer studies of the tin(IV) complexes [Sn(H4Bz4DH)₂Cl₄H₂O] (7), [Sn(H4BzPS)₂Cl₄H₂O] (8) with 4-benzoylpyridine thiosemicarbazone (H4Bz4DH) and the correspondent semicarbazone (H4BzPS) were performed. The isomer shifts decrease upon coordination due to the variation in the percentage of s character as tin changes from approximately sp³ hybridization in the tin salts to sp³d² in the octahedral or sp³d³ in the heptahedral complexes. The Moessbauer parameters of compound (4) showed the existence of two tin(IV) sites, which have been attributed to the presence of the cis and trans isomers.

[en] Moessbauer parameters like isomer shift, quadrupole splitting and line width measured at liquid helium temperature for six isomer pairs of cis-trans Ir(III) complexes are reported. An ¹⁰²Os/Nb source was used. The data obtained suggest that although the appearance of the two β picoline complexes was very different, the trans product being red and macrocrystal-line while the cis was a yellow powder, it is improbable that these are cis and trans isomers. The quadrupole splitting of the red product suggests both are trans species. (T.I.)

[en] We characterize Cesàro–Orlicz function spaces $Ce{s}_{\mathrm{\phi <!--\; ??\; -->}}$ containing order isomorphically isometric copy of $l^{\mathrm{\infty <!--\; ???\; -->}}$ under some mild assumption imposed on the Orlicz function $\mathrm{\phi <!--\; ??\; -->}$. We discuss also some useful applicable sufficient conditions for the existence of such a copy.

[en] It is well known that polyamines induce a folding transition from an elongated coil to a compact globule state for giant DNA larger than several tens of kbp (kilo base pairs). Here, we studied the interaction between compact DNA molecules in the presence of linear and branched-chain isomers of polyamines. We compared the stability of the assembly among plural number of compact DNA molecules generated by laser trapping. As a result, the assembly of compact DNAs with a linear-chain polyamine is stable even after the laser is switched off. On the other hand, the assembly of DNAs with a branched-chain polyamine disperses into individual compact DNAs when the laser is switched off. Thus, compact DNAs with linear- and branched-chain polyamines attract and repel each other, respectively. This difference in the effects of linear and branched polyamines is discussed in terms of the steric interaction between negatively charged double-strand DNA and cationic polyamines.

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[en] Isocyanic acid (HNCO) is a well-known interstellar molecule. Evidence also exists for the presence of two of its metastable isomers in the interstellar medium: HCNO (fulminic acid) and HOCN (cyanic acid). Fulminic acid has been detected toward cold and lukewarm sources, while cyanic acid has been detected both in these sources and in warm sources in the Galactic Center. Gas-phase models can reproduce the abundances of the isomers in cold sources, but overproduce HCNO in the Galactic Center. Here we present a detailed study of a gas-grain model that contains these three isomers, plus a fourth isomer, isofulminic acid (HONC), for four types of sources: hot cores, the warm envelopes of hot cores, lukewarm corinos, and cold cores. The current model is partially able to rationalize the abundances of HNCO, HOCN, and HCNO in cold and warm sources. Predictions for HONC in all environments are also made.