New neutron-rich isotopes in the scandium-to-nickel region,produced by fragmentation of a 500 MeV/u86Kr beam

We have measured production cross-sections of the new neutron-rich isotopes⁵⁸Ti,⁶¹V,⁶³Cr,⁶⁶Mn,⁶⁹Fe,⁷¹Co and neighbouring isotopes that have been identified as projectile fragments from reactions between a 500 MeV/u⁸⁶Kr beam and a beryllium target. The isotope identification was performed with the zero-degree magnetic spectrometer FRS at GSI, using in addition time-of-flight and energy-loss measurements. The experimental production cross-sections for the new nuclides and neighbouring isotopes are compared with an empirical parametrization. The resulting prospects for reaching even more neutron-rich isotopes, such as the doubly-magic nuclide⁷⁸Ni, are discussed.This work is part of the Ph.D. Thesis of M. Weber     

Baryon sum rules and chiral symmetry breaking

In an SVZ-type approach sum rules for baryonic currents have been investigated, without radiative QCD corrections but with the inclusion of non-perturbative terms due to the non-vanishing vacuum expectation value of the quark-antiquark condensate. We give upper bounds for baryon masses, which allow a choice of optimal interpolating operators for low-lying baryon states. The results show that the mentioned vacuum expectation value not only sets the scale for parity splitting but also for the masses of the baryons directly. The alternative way of explicit symmetry breaking by quark masses has also been investigated in the same technical framework.     

Results from the mainz neutrino mass experiment

The presently lowest limit for the mass of the electron neutrino is m _ν<2.2 eV/c ² 95% C.L.) derived from measurements at Mainz up to 1999. The data taken in 2000 are not fully analyzed yet, but limits of possible distortions as reported by the Troitsk group can be given.     

Computer-aided design (CAD) of Mn(II) complexes: superoxide dismutase mimetics with catalytic activity exceeding the native enzyme

New Mn(II) macrocyclic pentaamine complexes derived from the biscyclohexyl-pyridine complex, M40403 ([manganese(II)dichloro[(4R,9R,14R,19R)-3,10,13,20,26-pentaazatetracyclo[20.3.1.0.(4,9)0(14,19)]hexacosa-1(26),-22(23),24-triene]]), are described here. The complex M40403 was previously shown to be a superoxide dismutase (SOD) catalyst with rates for the catalytic dismutation of superoxide to oxygen and hydrogen peroxide at pH = 7.4 of 1.2 x 10(+7) M(-1) s(-1).(1) The use of the computer-aided design paradigm reported previously for this class of Mn(II) complexes(2,3) led to the prediction that the 2S,21S-dimethyl derivative of M40403 should possess superior catalytic SOD activity. The synthesis of this new macrocyclic Mn(II) complex, [manganese(II)dichloro[2S, 21S-dimethyl-(4R,9R,14R,19R)-3,10,13,20,26-pentaazatetracyclo[20.3.1.0.(4,9)0(14,19)]hexacosa-1(26),22(23),24-triene]], 5, was accomplished via a high yield template condensation utilizing the linear tetraamine, N,N'-Bis[(1R,2R)-[2-(amino)]cyclohexyl]-1,2-diaminoethane, 1, 2,6-diacetylpyridine, and MnCl(2) to form the macrocyclic diimine complex, 2, which then is reduced. The two other possible dimethyl diastereomers of 5 (2R,21R-dimethyl,3, and 2R,21S-dimethyl, 6) were also prepared via reduction of the diimine complex 2. Two of these complexes, 3 and 5, were characterized by X-ray structure determination confirming their absolute stereochemistry as 2R,21R-dimethyl and 2S,21S-dimethyl, respectively. The results of the MM calculations which predict that the 2S,21S-dimethyl complex, 5, should be a high activity catalyst and that the 2R,21R-dimethyl complex, 3, should have little or no catalytic activity are presented. The catalytic SOD rates for these complexes are reported for each of these complexes and a correlation with the modeling predictions is established showing that 2R,21R-complex, 3, has no measurable catalytic rate, while the 2R,21S complex, 6, is identical to M40403, and the 2S,21S- complex, 5, possesses a very fast rate at pH = 7.4 of 1.6 x 10(+9) M(-1) s(-1) exceeding that of the native mitochondrial MnSOD enzymes.     

DELAYED PLATING RECOVERY OF DIPLOID YEAST EXPOSED TO ULTRAVIOLET LIGHT BETWEEN 254 AND 313 nm WAVELENGTH

Abstract— Diploid yeast cells exposed to UV-light of different wavelengths in the region between 254 and 313 nm were assessed for their ability of delayed plating recovery. They were either held in non-nutrient suspension ('liquid holding') or on non-nutrient agar before final plating. Thus it was possible to distinguish between real and apparent recovery due to cell multiplication. The experiments showed that no delayed plating recovery was found beyond 295 nm wavelength UV.     

非结构网格上一种新型的高分辨率高精度无波动的有限元格式

在非结构网格上构造出无波动无自由参数耗散性有限元格式 ,即NND有限元格式 .通过若干个典型二维跨音速和超音速可压缩无粘定常流动的算例证明这确是一个高精度的 ,对激波具有高分辨率的无波动的新型有限元格式 .特别与网格自适应相结合 ,可得到十分满意的结果     

Renormalization of the inverse square potential

The quantum-mechanical D-dimensional inverse square potential is analyzed using field-theoretic renormalization techniques. A solution is presented for both the bound-state and scattering sectors of the theory using cutoff and dimensional regularization. In the renormalized version of the theory, there is a strong-coupling regime where quantum-mechanical breaking of scale symmetry takes place through dimensional transmutation, with the creation of a single bound state and of an energy-dependent s-wave scattering matrix element.