The molecular structure of the N-chloroimine product of rearrangement of N,N-dichloroperfluoroaniline: A study by gas-phase electron diffraction

A gas-phase electron-diffraction study of the product of rearrangement of N,N-dichloro-perfluoroaniline has assisted in establishing it to be the N-chloroimine, I, rather than the azepine, II. The molecule is found to be planar apart from atoms Cl13 and F14. The detailed dimensions shown in Fig. 2 were obtained by least-squares refinements in which several structural constraints were applied to reduce the total number of independent parameters. Of particular interest is the evidence for overcrowding around the CN bond: ∠N7C1C2 = 128°, ∠C18N7C1 = 126°, ∠N7C1C6 = 118° ; the distance C18 β F9 is 2.73 Å.     

General cases of the pseudoquadrupole interaction in169Tm

Clauser and Mössbauer [1] showed that the second order (in perturbation theory) magnetic hyperfine interaction, the so called pseudoquadrupole inter-action, in the¹⁶⁹Tm Mössbauer effect can produce apparent isomer shifts. While they assumed two isolated singlets and simplified the coupling, we will show that the second order magnetic hyperfine coupling can be observed in general for any kind of crystalline electric field (CEF) wavefunctions, and that the coupling between many states must often be considered in calculating it. Furthermore since the first order magnetic coupling of the excited CEF states is important, the interaction is best accounted for by diagonalization of the full magnetic hyperfine and CEF Hamiltonian. Examples of the effects that may occur are presented.Work supported by the U. S. Department of Energy.     

Einstein. a centenary volume

“At a meeting early in 1976, the International Commission on Physics Education took note of the fact that 14 March 1979 would be the centenary of the birth of Albert Einstein.…This book is the result. We hope that, in the spirit of our intentions, the book will appeal to a wide range of readers. In planning it, however, we had especially in mind both teachers and students of physics at secondary and undergraduate (tertiary) levels. Our main purpose has been to provide something of a picture of Einstein the man, of his scientific work and its subsequent significance, and of his role as a humanitarian and a World statesman.”     

Visual spatial memory is enhanced in female rats (but inhibited in males) by dietary soy phytoestrogens

Background  

In learning and memory tasks, requiring visual spatial memory (VSM), males exhibit superior performance to females (a difference attributed to the hormonal influence of estrogen). This study examined the influence of phytoestrogens (estrogen-like plant compounds) on VSM, utilizing radial arm-maze methods to examine varying aspects of memory. Additionally, brain phytoestrogen, calbindin (CALB), and cyclooxygenase-2 (COX-2) levels were determined.     

The structure formed by the deposition of a sub-monolayer quantity of platinum onto Cu(110) investigated using medium energy ion scattering

The structure of 0.35 monolayers of platinum deposited onto Cu(110) has been investigated using medium energy ion scattering. Quantitative analysis of the data has been performed using the VEGAS routine. It was found that platinum atoms mostly occupy the second layer with a first interlayer distance of d₁₂ = 123 ± 4 pm and a separation of first and third layers of d₁₃= 142_? 10^+ 4 pm. These represent a contraction of 4% and an expansion of 11% respectively from the ideal termination of the Cu(110) surface. There is clear evidence of the presence of some platinum in the third layer.