The beta decay of176m Lu

The shape factors of the 1^?→2⁺ and 1^?→0⁺ beta transitions and theβ-γ directional correlation of^176m Lu have been measured. An analysis in terms of nuclear matrix elements is given.     

Electronic surface properties of uhv-cleaved III–V compounds

Combined CPD and photoemission measurements were performed on uhv-cleaved surfaces of the III–V compounds InAs, GaSb, GaAs and GaP with moderate p-type and n-type dopings. Except for n-type GaP these materials show practically no band bending. N-type GaP exhibits surface Fermi level stabilization at 0.55 eV below the conduction band edge. This is ascribed to an intrinsic empty surface state band in the forbidden zone. On the basis of our experiments together with available data from literature we propose an empirical model for the (110) plane of III–V compounds containing In or Ga as metal and Sb, As or P as non-metal atoms from which the lower edge of the empty surface state band can be predicted. The model indicates that for any of these compounds except for GaP no empty surface state band exist in the band gap on the (110) surface.     

13C?1H spin–spin couplings in cyclic α,β-unsaturated enones and their protonated derivatives. Measurements and quantum chemical calculations

Direct and long-range ¹³C? ¹H coupling constants are presented for the enone moieties of cyclopent-2-enone, cyclohex-2-enone and their protonated derivatives. A correlation is given between the experimental values and the results of quantum chemical calculations (CNDO/2, INDO). The existing calculations are modified in order to improve the relationship between the calculated and experimental results.     

BIOLOGISCHE WIRKUNGEN PHOTOCHEMISCHER WASSERSTOFFPEROXYDBILDUNG:

Abstract— As previously demonstrated, there is a considerable increase in the photodynamic activity of anthraquinone-sulphonic acid on the addition of ethylene glycol, glycerol and sugars in concentrations of the order of 0.4 M . This system exhibits cytostatic activity. With H₂O₂ at higher concentrations there is also formation of aldehydes in approximately equivalent yields as follows:
R.CH₂OH+Q → QH₂+R.CHO
QH₂+O₂→ Q+H₂O₂
In accordance with the recent results of Warburg this accounts for the fundamental importance of glyceraldehyde in cancer research.
Our results on the irradiation of Proteus vulgaris SG2 in buffered medium with the addition of glycerin to anthraquinone-sulphonic acid show the existence of a similar cytostatic effect. One hour's irradiation with visible light reduces the cell count by about 50 per cent.     

Monte Carlo calculation of angular transmission functions for small angle scattering

We define an angular transmission function η in the center of mass system. The convolution of the differential cross section σ with η yields the signal in the laboratory system. For the case of elastic small angle scattering by spherically symmetric potentials we calculate η by a Monte Carlo method. Random positions are taken in the beam defining collimators, resulting in a trajectory with a deflection angle at the scattering centre. These deflection angles are transformed to the c.m. system with the small angle tranformation formulae. From the distribution we calculate η as a histogram and the central moments of η. The function η depends on the velocity ratio and on the mass ratio of the scattering partners. We store the results in such a way that the central moments can be calculated afterwards for all mass and velocity ratios. By using the central moments the convolution integral can be reduced to a simple weighted sum of σ-values at different scattering angles. The r.m.s. deviations of the central moments scale with N^{$\text{1}\text{2}$}, with N the number of Monte Carlo trajectories. A typical deviation is 1% in the second order moment for N = 2 × 10⁴, increasing slightly with increasing order of the moments. This method of calculation gives a large degree of freedom for optimisation of the collimation geometry. The use of an angular transmission function defined in the center of mass system gives a good insight in the experimental reflection of the physical events. As an example we apply the method to the case of small angle scattering of Ar as a primary beam by Kr as a secondary beam and the inverse configuration of Kr by Ar.     

There is no continuous projection from the measurable functions on the square onto the measurable functions on the interval

It is proved that the space of functions constant on vertical lines is not complemented in the space of all measurable functions on the unit square (with the topology of convergence in measure). The analogous results is proved for the space of all measurable functions on the product of two probability spaces, one of which is atomless. This research was partially supported by National Science Foundation grant N.S.F. GP 28577.     

An improved power supply for the magnet in a.c. modulated Zeeman atomic absorption spectrometry

This note describes a simple power supply for a magnet to be used in a.c. ZAA spectrometry. The modified sine wave shape of the 50 Hz 10 kG magnetic field allows a 0.5 ms period at zero field to perform the zero field intensity measurement. At lower maximum field strength, the zero field period can be extended.