Skin Cancer Risks Avoided by the Montreal Protocol—Worldwide Modeling Integrating Coupled Climate‐Chemistry Models with a Risk Model for UV

The assessment model for ultraviolet radiation and risk “AMOUR” is applied to output from two chemistry‐climate models (CCMs). Results from the UK Chemistry and Aerosols CCM are used to quantify the worldwide skin cancer risk avoided by the Montreal Protocol and its amendments: by the year 2030, two million cases of skin cancer have been prevented yearly, which is 14% fewer skin cancer cases per year. In the “World Avoided,” excess skin cancer incidence will continue to grow dramatically after 2030. Results from the CCM E39C‐A are used to estimate skin cancer risk that had already been inevitably committed once ozone depletion was recognized: excess incidence will peak mid 21st century and then recover or even super‐recover at the end of the century. When compared with a “No Depletion” scenario, with ozone undepleted and cloud characteristics as in the 1960s throughout, excess incidence (extra yearly cases skin cancer per million people) of the “Full Compliance with Montreal Protocol” scenario is in the ranges: New Zealand: 100–150, Congo: ?10–0, Patagonia: 20–50, Western Europe: 30–40, China: 90–120, South‐West USA: 80–110, Mediterranean: 90–100 and North‐East Australia: 170–200. This is up to 4% of total local incidence in the Full Compliance scenario in the peak year.     

Exclusive deuteron electrodisintegration at high neutron recoil momentum

We have determined the ²H(e, e′p)n cross section for neutron recoil momenta between 295 and 500 MeV/c. In this region the ³D₁ state contribution is predominant in the deuteron wave function. The high excitation energy (E_cm^np = 179 MeV) and the small momentum transferred (|;q_cm|;² = 1.66 fm^?) emphasize the influence of isobar configurations (IC). Experimental data are compared with calculations including isobar contributions, mesonic exchange currents and final state interactions.     

Deep inelastic electron scattering on light nuclei

Czechoslovak Journal of Physics -     

High-resolution diode-laser spectroscopy of calcium

Saturated-absorption signals on the calcium 657 nm transition are observed by direct absorption using diode lasers and a high flux atomic-beam cell. Line-widths as narrow as 65 kHz are observed with a high signal-to-noise ratio. Prospects for using this system as a compact wavelength/frequency reference are considered.     

Temperature dependence of self-broadening in molecular-oxygen spectrum

Summary The ^p P(k=9) magnetic-dipole transition of the oxygen 0-0 vibrational band of the red systemb ¹Σ _g ⁺ ←X ³Σ _g ⁻ was observed with absorption spectroscopy using a tunable CW diode laser. A systematic investigation of the self-collisional broadening was performed for different gas pressures and temperatures. The temperature dependence of the self-broadening coefficient was determined to beT ^{−(1.02±0.05)}. Our results are of interest for collisional theory and as reference data in atmospheric monitoring applications. The authors of this paper have agreed to not receive the proofs for correction.     

How boron incorporation during Si1−xGex chemical vapor deposition degrades the Ge profile

The effect of boron incorporation during chemical vapor deposition of SiGe thin films from silane, germane, diborane, and hydrogen gas mixtures is investigated. It is shown that boron incorporation during SiGe thin-film growth degrades the Ge profile under certain growth conditions when the boron concentration is high enough (>10¹⁹ cm⁻³). In single-wafer atmospheric-pressure processes we find that no Ge concentration depression occurs at deposition temperatures above 675 °C. In multi-wafer atmospheric-pressure processes we find an increasingly occurring depression of the Ge concentration along the wafer stack, even at temperatures above 675 °C. In low-pressure processes, high-level in-situ doping of SiGe with boron is possible at temperatures as low as 550 °C without any degradation of the Ge profile. Thus LPCVD is superior to APCVD with respect to high-level in situ doping of SiGe with boron. The presence or absence of Ge profile degradation in boron-doped SiGe thin films is explained by the discussion of growth rate enhancement phenomena. Received: 15 September 1997 / Accepted: 7 November 1997     

Polarization and velocity dependence of associative ionization in Na(3p)+Na(3p) collisions

We have excited Na atoms of two counterrunning thermal beams by means of linearly polarized laser light and have investigated associative ionization processes. To this end we measured the total ionization signal as a function of the angle ? between light polarization and the relative collision velocity. Velocities of the excited atoms were selected by exploiting the Doppler effect. We found an increasing polarization dependence at increasing collision velocities. At all velocities the preparation of the collision partners in the |M _j |=1/2 sublevel of the Na² P _3/2 state is most efficient in producing ionization.     

Studies on the reaction of 2-aminoacetophenone with thiophosgene

The reaction of 3- and 4-aminoacetophenone with thiophosgene in a chloroform-water-calcium carbonate mixture at room temperature results in good yields of the related, known isothiocyanates. At first, however, we failed in all our attempts to produce 2-isothiocyanatoacetophenones with this reaction. Closer inspection of the reaction showed, that the product distribution depends upon the concentration of hydrogen ions pro-ducted and on the reaction time. When the reaction was followed with thin-layer chromatography, it was observed that the isothiocyanates formed first. In the further course of the reaction, they were converted to the 4-methylene-2-oxo-3,1-benzothiazines by the action of protons. The final products of the reaction were the 4-(3,1-benzothiazin-4-yl)-methylene-3,1-benzothiazines, formed from the monomer in a dimerization process. Depending upon the time the protons were removed from the reaction mixture, different products could be isolated.