Anwendung von Photozellen beim Titrieren

Ohne Zusammenfassung     

Theoretical study of the AlO blue-green (B2∑+−X2∑+ band system

Two independent, extensive theoretical calculations are reported for the relative band strengths of the AlO (B²∑⁺?X²∑⁺) blue-green system and for the radiative lifetimes of the lowest few vibrational levels of the B²∑⁺ state. The theoretical lifetimes, which include a small (<0.5%) contribution from bound-bound transitions into the A²Π state, are in excellent agreement with laser fluorescence studies. The theoretical lifetimes increase monotonically and very slowly with increasing vibrational quantum number. The relative band strengths for the blue-green system derived from the two theoretical calculations are in excellent agreement, but differ systematically from the relative band strengths of Linton and Nicholls. Our results suggest that their self-absorption corrections are not large enough, resulting in relative intensities that are too large, especially for the weak bands with r centroids less than 1.5Å.     

The Theory of the Firm

Journal of the Operational Research Society -     

Strategies for vectorizing the sparse matrix vector product on the CRAY XMP,CRAY 2, and CYBER 205

Large randomly sparse matrix vector products are important in a number of applications in computational chemistry, such as matrix diagonalization and the solution of simultaneous equations. Vectorization of this process is considered for the CRAY XMP, CRAY 2, and CYBER 205, using a matrix of dimension of 20 000 with from 1% to 6% nonzeros. Efficient SCATTER/GATHER capabilities add coding flexibility and yield significant improvements in performance. For the CYBER 205, it is shown that minor changes in the IO can reduce the CPU time by a factor of 50. Similar changes in the CRAY codes make a far smaller improvement.     

A ballon-borne experiment for observations of the near-infrared cosmological background

Summary We present here a ballon-borne experiment to measure the near-infrared cosmological background in the (1÷5) μm range. The instrument, a liquid helium cooled telescope (250 mm,F/2), was built in the infrared laboratory of Istituto TE.S.R.E./C.N.R.-Bologna (Italy) collaboration with the Haverford College (PA-U.S.A.). It will be launched from the NSBF base of Palestine (Texas-U.S.A.) in May 1989. To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee.