Rana boylii

Number of Pages: 2Integrative BiologyGeological Science

Eleutherodactylus augusti

Number of Pages: 4Integrative BiologyGeological Science

Rana muscosa

Number of Pages: 2Integrative BiologyGeological Science

Lampropeltis zonata

Number of Pages: 4Integrative BiologyGeological Science

Relationships among Generalized Phase‐Space Distributions

The generalized phase‐space distributions, including the Wigner distribution, are presented in terms of expected values of generating operators. A generalization of the Weyl correspondence is obtained to provide expressions for generalized Wigner equivalents. Finally, rather simple relationships are obtained connecting the generalized phase‐space distributions to the Wigner distribution; and similar relationships are obtained for the generalized Wigner equivalents. In particular, it appears that, among the class considered, there is no reason to use any distribution other than the Wigner for performing any calculations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69967/2/JMAPAQ-10-2-233-1.pd

Systematics of Microhylid Frogs, Genus Oreophryne, from the North Coast Region of New Guinea

Fig. 4. Regression of internarial span on snout­vent length in two samples of Oreophryne biroi from Papua New Guinea. Squares, specimens from Madang Prov.; crosses, specimens from East Sepik Prov.Published as part of <i>ZWEIFEL, RICHARD G., MENZIES, JAMES I. & PRICE, DAVID, 2003, Systematics of Microhylid Frogs, Genus Oreophryne, from the North Coast Region of New Guinea, pp. 1-32 in American Museum Novitates 3415</i> on page 10, DOI: 10.1206/0003-0082(2003)415<0001:SOMFGO>2.0.CO;2, <a href="http://zenodo.org/record/10111440">http://zenodo.org/record/10111440</a&gt

Quantum Statistics and Slow Neutron Scattering by Gases

A surprisingly simple expression in ``closed form'' for the cross section d2σ/dΩdϵ for the scattering of thermal neutrons (including polarized neutrons) from an ideal quantum gas is derived. This result extends the work of Van Hove on the quantum gas. An expansion is obtained for dσ/dϵ. The case of elastic scattering is treated separately. From these expressions is obtained a criterion for ignoring the statistics of the scatterer in favor of classical (Boltzmann) statistics. This criterion should have some validity for weakly interacting systems. It is shown that the effects of statistics on the neutron cross section for a helium‐4 gas range from 5% or less for the noninteracting gas up to as much as 40% for the interacting system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70882/2/JCPSA6-47-12-4923-1.pd

The [4+2]‐Cycloaddition of α‐Nitrosoalkenes with Thiochalcones as a Prototype of Periselective Hetero‐Diels–Alder Reactions—Experimental and Computational Studies

The [4+2]‐cycloadditions of α‐nitrosoalkenes with thiochalcones occur with high selectivity at the thioketone moiety of the dienophile providing styryl‐substituted 4H‐1,5,2‐oxathiazines in moderate to good yields. Of the eight conceivable hetero‐Diels–Alder adducts only this isomer was observed, thus a prototype of a highly periselective and regioselective cycloaddition has been identified. Analysis of crude product mixtures revealed that the α‐nitrosoalkene also adds competitively to the thioketone moiety of the thiochalcone dimer affording bis‐heterocyclic [4+2]‐cycloadducts. The experiments are supported by high‐level DFT calculations that were also extended to related hetero‐Diels–Alder reactions of other nitroso compounds and thioketones. These calculations reveal that the title cycloadditions are kinetically controlled processes confirming the role of thioketones as superdienophiles. The computational study was also applied to the experimentally studied thiochalcone dimerization, and showed that the 1,2‐dithiin and 2H‐thiopyran isomers are in equilibrium with the monomer. Again, the DFT calculations indicate kinetic control of this process