On the observation of the fine structure effect in non-relativistic (e, 2e) processes

The spin asymmetry arising in an (e,2e) process using spin-polarized incoming electrons with non-relativistic energies is shown to be dominated by the fine structure effect if a suitable kinematical regime is chosen. Calculations in the distorted wave Born approximation (DWBA) for both the triple differential cross-section and the spin asymmetry are presented for the inner shell ionization of argon. This process would provide an accessible target for existing experimental set-ups.     

N=82 shell quenching of the classical r-process "waiting-point" nucleus 130Cd

First beta- and gamma-spectroscopic decay studies of the N=82 r-process "waiting-point" nuclide 130Cd have been performed at CERN/ISOLDE using the highest achievable isotopic selectivity. Several nuclear-physics surprises have been discovered. The first one is the unanticipatedly high energy of 2.12 MeV for the [pi g(9/2) multiply sign in circle nu g(7/2)] 1(+) level in 130In, which is fed by the main Gamow-Teller transition. The second surprise is the rather high Q(beta) value of 8.34 MeV, which is in agreement only with recent mass models that include the phenomenon of N=82 shell quenching. Possible implications of these new results on the formation of the A approximately 130 r-process abundance peak are presented.     

Study of the Heterocyclic-Substituted Platinum-1,2-Enedithiolate 3ILCT Excited States by Transient Absorption Spectroscopy

The photoluminescent 1,2-enedithiolate complexes, (dppe)Pt{S₂C₂(2-quinoxaline)(H)}, [L₂Pt{S₂C₂(2-pyridinium)(H)}]⁺ where L₂ = dppm and dppe, [L₂Pt{S₂C₂(4-pyridinium)(H)}]⁺, [L₂Pt{₂C₂(N-Methyl-4-pyridinium)(H)}]⁺ and [L₂Pt{S₂C₂(CH₂CH₂-N-2-pyridinium)}]⁺ where L₂ = dppm, dppe, and dppp are room temperature dual emitters where the emissions have thiolate to heterocycle * intraligand charge transfer character (ILCT) singlet and triplet character. The pyridinium complexes have strong triplet-triplet absorption bands at approximately 400, 520 and 630 nm with a weaker band at 800 nm while (dppe)Pt{S₂C₂(2-quinoxaline)(H)} has strong triplet-triplet absorption bands at 385 and 550 nm with weaker bands at 610 and 805 nm. By fitting the decay of the transients to single exponential kinetics, the ³ILCT* lifetimes of the pyridinium complexes where determined to be 0.7 to 15.9 s (DMSO) while the ₃ILCT* lifetime of (dppe)Pt{S₂C₂(2-quinoxaline)(H)} was determined to be 2.8 s (CH₃CN). The transient absorption spectra of the complexes is affected by the appended heterocycle rather than the bulk of ancillary phosphine ligand or whether the heterocycle is protonated or alkylated.     

Crossover between thermally assisted and pure quantum tunneling in molecular magnet Mn12-acetate

The crossover between thermally assisted and pure quantum tunneling has been studied in single crystals of high spin (S = 10) uniaxial molecular magnet Mn12 using micro-Hall-effect magnetometry. Magnetic hysteresis and relaxation experiments have been used to investigate the energy levels that determine the magnetization reversal as a function of magnetic field and temperature. These experiments demonstrate that the crossover occurs in a narrow ( approximately 0. 1 K) or broad ( approximately 1 K) temperature interval depending on the magnitude of the field transverse to the anisotropy axis.     

First On-line beta-NMR on oriented nuclei: magnetic dipole moments of the (nup(1/2))(-1) 1/2(-) ground state in 67Ni and (pip(3/2))(+1) 3/2(-) ground state in 69Cu

The first fully on-line use of the angular distribution of beta emission in detection of NMR of nuclei oriented at low temperatures is reported. The magnetic moments of the single valence particle, intermediate mass, isotopes 67Ni(nup(-1)(1/2);1/2(-)) and 69Cu(pip(1)(3/2);3/2(-)) are measured to be +0.601(5) &mgr;(N) and +2.84(1) &mgr;(N), respectively, revealing only a small deviation from the neutron p(1/2) single-particle value in the former and a large deviation from the proton p(3/2) single-particle value in the latter. Quantitative interpretation is given in terms of core polarization and meson-exchange currents.     

Recovery of embryos of Zizania palustris following exposure to liquid nitrogen

Factors affecting survival of embryos of Zizania palustris after exposure to liquid nitrogen were investigated. Moisture content was the most critical factor. Embryos desiccated to a moisture content between 0.36 and 0.56 g water per g dry weight had highest survival after liquid nitrogen exposure (56 +/- 4% and 52 +/- 9% respectively). The recovery of embryos in the light following liquid nitrogen exposure also influenced survival. Survival increased from 35 +/- 4% to 56 +/- 4% when embryos containing 0.36 g water per g dry weight were recovered in the dark compared to light. Embryos exposed to desiccation and freezing stresses were subject to increased levels of lipid peroxidation. Light exacerbated lipid peroxidation in recovering embryos. Furthermore, catalase and peroxidase, enzymes involved in reducing reactive oxygen species, increased in activity in response to stress, and were further up-regulated in tissues recovered in the light. This study suggests that there are a number of factors influencing the survival of tissues exposed to liquid nitrogen and recovery procedures that reduce oxidative stress should be employed.     

High-performance affinity chromatography: a powerful separation technique

Analyses of complex biochemical samples can be performed within one minute using a method which combines the selectivity of affinity chromatography with the speed of high-performance liquid chromatography.     

Software Reviews

Alcohol Discovery Lab Voltage Plotter USA Social and Geographical Database Hometown—A Local Area Study Heat and Light Drug Alert     

Glaspunkte von textilen Polyamidfasern. II. Beziehungen zwischen Glaspunkt und Anf?rbbarkeit

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