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1.
K. O. Zell H. -G. Friederichs B. Heits D. Hippe H. W. Schuh P. von Brentano C. Protop 《Zeitschrift für Physik A Hadrons and Nuclei》1976,3(3):371-380
77Se has been investigated by the reaction74Ge(,n) at 14 MeV. Gamma singles spectra, gamma angular distributions and gamma-gamma coincidences have been taken. A level scheme has been established, spins and parities have been assigned. States of a rotational band on the 1/2– ground state, a rotational band on the 5/2– 249.7 keV state and an anormal band have been identified.
Nuclear Reaction
74Ge(,n )E
=14 MeV; measuredE
,I
,--Coin.,-ang. distr.77Se deduced levels,J, . Enriched target, Ge (Li). 相似文献
2.
3.
Busico V Cipullo R Cutillo F Friederichs N Ronca S Wang B 《Journal of the American Chemical Society》2003,125(41):12402-12403
The presence of "free" trimethylaluminum (TMA) in methylalumoxane (MAO) solutions can be highly detrimental to the performance of metallocene and "post-metallocene" olefin polymerization catalysts. The most used strategy to remove "free" TMA is to evaporate MAO solutions to dryness, until a free-flowing white powder ("solid MAO") is left. This procedure is tedious and potentially hazardous, because in some cases the distillate is a concentrated hydrocarbon solution of TMA. Moreover, "solid MAO" is poorly soluble in common polymerization media, and once in solution it can regenerate TMA to some extent. This communication reports on a facile alternative, which consists in the controlled addition of a sterically hindered phenol, such as 2,6-di-tert-butylphenol, effectively trapping "free" TMA. We show here that 2,6-di-tert-butylphenol/MAO solutions activate equally well the dichloro-precursors of well-known zirconocene and bis(phenoxyimine)Ti catalysts, and that their use in propene polymerization results in a substantially higher productivity, polymer stereoregularity, and/or average molecular mass compared with activation by MAO alone. 相似文献
4.
R. Geiger P. von Brentano H. G. Friederichs B. Heits W. Schuh K. O. Zell H. Weigmann A. Berinde 《Zeitschrift für Physik A Hadrons and Nuclei》1974,271(2):129-137
The decay scheme of112Cd has been studied by γ-ray spectroscopy with the110Pd(α, 2nγ) reaction. Spin and parity assignments were made on the basis of coincidence measurements, angular distributions and excitation functions. Twelve new energy levels were established. A vibrational-like positive-parity band up to spin 8+ and a negativeparity side band 5?, (7?), (9?) were found. For the negative-parity states a (vj, vh11/2) configuration is suggested. Nuclear Reactions:110Pd(α,2nγ),E α =15–22.5 MeV; measuredE γ ,E γ , (E,E γ ),E γ (θ),γ-γ- coincidence;112Cd deduced levels,J; enriched target. 相似文献
5.
D. Hippe B. Heits H. -W. Schuh K. O. Zell H. -G. Friederichs P. von Brentano 《Zeitschrift für Physik A Hadrons and Nuclei》1975,273(4):349-357
The93Nb(α, 2nγ)95Tc reaction has been studied at a bombarding energy of 22.5 MeV using Ge(Li)-detectors. Gamma singles spectra, gamma-gamma coincidences, excitation functions and gamma angular distribution have been obtained. A level scheme has been constructed. Spin and parity assignments up to 29/2+ are given. 相似文献
6.
K. O. Zell H. -G. Friederichs B. Heits D. Hippe H. W. Schuh P. von Brentano C. Protop 《Zeitschrift für Physik A Hadrons and Nuclei》1976,276(4):371-380
77Se has been investigated by the reaction74Ge(α,nγ) at 14 MeV. Gamma singles spectra, gamma angular distributions and gamma-gamma coincidences have been taken. A level scheme has been established, spins and parities have been assigned. States of a rotational band on the 1/2? ground state, a rotational band on the 5/2? 249.7 keV state and an anormal band have been identified. Nuclear Reaction 74Ge(α,n γ)E α=14 MeV; measuredE γ ,I γ ,γ-γ-Coin.,γ-ang. distr.77Se deduced levels,J, π. Enriched target, Ge (Li). 相似文献
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To improve the forecasts of weather extremes, we propose a joint spatial model for the observations and the forecasts, based on a bivariate Brown-Resnick process. As the class of stationary bivariate Brown-Resnick processes is fully characterized by the class of pseudo cross-variograms, we contribute to the theorical understanding of pseudo cross-variograms refining the knowledge of the asymptotic behaviour of all their components and introducing a parsimonious, but flexible parametric model. Both findings are of interest in classical geostatistics on their own. The proposed model is applied to real observation and forecast data for extreme wind gusts at 119 stations in Northern Germany. 相似文献
9.
This paper describes an interactive decision support system called Opti-Link which has been developed for a company operating
in the area of waste and raw material management. Built around a specific transportation problem, the system is used to maximize
the revenue generated by selling waste paper to paper mills. Furthermore, the dual variables of the linear program allow the
planner to identify upper bounds for setting bid prices to buy waste paper from waste collection companies. First operational
results indicate a significant increase in profit while at the same time the duration of the planning process could be cut
by more than half. 相似文献
10.
C. Protop B. Heits H. G. Friederichs K. O. Zell P. von Brentano 《Zeitschrift für Physik A Hadrons and Nuclei》1974,271(1):65-68
Using the (α, 2nγ) reaction we have established a partial decay scheme of73As. A positive parity band built on the 428 keV 9/2+ level is interpreted as a decoupled band. 相似文献