Results from Super-Kamiokande and K2K

Results from Super-Kamiokande-I’s entire 1496 live days of solar neutrino data are presented, including the absolute flux, energy spectrum, zenith angle (day/night) and seasonal variation. The possibility of MSW and vacuum oscillations is discussed in light of these results. Results from the first 1289 days of Super-K-I’s atmospheric neutrino analysis are also presented, including the evidence for ν_μ →ν _τ oscillations, against ν_μ → ν_sterile oscillations, and the current limits on proton decay. Finally, results based on 56 × 10¹⁹ protons on target are given for the K2K long-baseline neutrino oscillation experiment.     

Crystal structure of dicyclohexano-18-crown-6 potassium 2-nitrophenoxide

The first crystal structure of a potassium cation complex with dicyclohexano-18-crown-6 is reported. The potassium 2-nitrophenoxide complex ofsyn-cis-syn dicyclohexano-18-crown-6 crystallizes in the triclinic space group P with cell constantsa=8.604(2),b=10.772(4),C=16.123(5)Å, =73.86(3)°,=77.61(3)°, =82.68(3)° andZ=2 forD _c =1.31 g cm^–3. Least-squares refinement based on 2742 observed reflections led to a final conventionalR value of 0.040. Dicyclohexano-18-crown-6 has the shape of a saddle with the potassium cation sitting at the saddlepoint. The structure of the 2-nitrophenoxide anion is dominanted by the quinoid resonance contributor. Because the complex is devoid of significant intercomplex interactions, it is a prototypical 1:1:1 complex. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82043 (26 pages).Now Mrs. K. M. Balo.     

Cyclic imides III. A study of the hydroxy- and methoxyphthalimidoacetic acids and the methyl methoxyphthalimidoacetates

The hydroxy- and methoxyphthalimidoacetic acids and the methyl methoxyphthalimidoacetates have been synthesized. The ultraviolet absorption spectra of these compounds in 95% ethanol, aqueous acid, and aqueous base are discussed. Structures are suggested for the hydroxy- and methoxyphthalamate ions which are formed in basic solution. The Gabriel-Colman rearrangements of methyl 3- and 4 - methoxyphthalimidoacetate give, respectively, 8-methoxy-4-hydroxy-3 - carbomethoxy-1(2H)-isoquinolone (VII) and 6-methoxy-4-hydroxy-3-carbomethoxy-1(2H)-isoquinolone (VIII).     

Divergence of the Bethe-Salpeter wave function at the origin

We point out an error in the proof of Nishijima et al. that the Bethe-Salpeter wave function for composite particles, lying on Regge trajectories, is finite. We describe a simple counter-example drawn from non-relativistic quantum mechanics and cite others from field theory.     

Determining the optimum wavelength pairs to use for molecular absorption thermometry based on the continuous-spectral lower-state energy

A novel technique for selecting wavelengths that optimize the temperature precision of absorption-based thermometry is developed. A single universal objective function considering continuous spectral lower-state energy , spectral absorbance intensities and an experimental noise level is derived and applied in a brute-force approach to analyze two-wavelength, Doppler-broadened H₂O vapor-absorbance thermometry in the 1.33-1.37 μm range. The results reveal the top wavelength pairs and their temperature precisions over a wide temperature range from 280 to 2800 K. Although the spectral database used includes over thousands of transitions in this spectral range, the top pairs are composed of only 12 unique wavelengths. This wavelength selection technique is able to help researchers choose key wavelengths that will perform well in practical applications.     

Cyclic imides. XII(i). Absorption and fluorescence spectra of 3-benzamidophthalimides

The ultraviolet absorption, fluorescence, and infrared absorption spectra of fifteen 3-benz-amidophthalimides are described. In general, the nature or position of the substituents on the benzamide moiety has little effect on the ultraviolet absorption and fluorescence spectra of these, compounds. The absorption baud at 271 nm is more sensitive to substituent variations than the other two bands (at 227 nm and 341 nm), indicating this band is a composite of bands observed in the spectra of 3-aminophthalimide and the substituted benzamide. The fluorescence of 3-amino-phthalirnide and the 3-benzamidophthalimides is due to the same transitions. The infrared absorption wavenumbers for the amide and imide vibrations of the 3-benzamidophthalimides are characterized.     

Crown ether complexes of potassium and thallium(I) 2- and 4-nitrophenoxides

18-Crown-6 and dicyclohexano-18-crown-6 complexes of potassium 2- and 4-nitrophenoxide, and 18-crown-6 complexes of thallium(I) 2- and 4-nitrophenoxide have been synthesized. Solvent effects on the visible spectra of the nitrophenoxide anions are independent of the nature of the cation and the nature of the complexing agent. The 18-crown-6 complex of thallium(I) 2-nitrophenoxide is a 1:2 complex. All the other complexes are 1:1. X-ray crystallographic examination of the potassium dicyclohexano-18-crown-6 complexes showed the potassium ion is octacoordinated in the 2-nitrophenoxide and heptacoordinated in the 4-nitrophenoxide.     

Sensitivity analysis of discrete Markov chains via matrix calculus

Markov chains are often used as mathematical models of natural phenomena, with transition probabilities defined in terms of parameters that are of interest in the scientific question at hand. Sensitivity analysis is an important way to quantify the effects of changes in these parameters on the behavior of the chain. Many properties of Markov chains can be written as simple matrix expressions, and hence matrix calculus is a powerful approach to sensitivity analysis. Using matrix calculus, we derive the sensitivity and elasticity of a variety of properties of absorbing and ergodic finite-state chains. For absorbing chains, we present the sensitivities of the moments of the number of visits to each transient state, the moments of the time to absorption, the mean number of states visited before absorption, the quasistationary distribution, and the probabilities of absorption in each of several absorbing states. For ergodic chains, we present the sensitivity of the stationary distribution, the mean first passage time matrix, the fundamental matrix, and the Kemeny constant. We include two examples of application of the results to demographic and ecological problems.