An Absorption Band of Formaldoxime at lambda9572

The third harmonic of the O [Single Bond] H band in formaldoxime vapor has been found to lie at lambda9572 (10,444.1 cm^—1) and under high dispersion has been resolved and found to resemble a parallel band of a symmetric rotator. Owing to the weakness of the lines near the center of the band a definitely unique rotational analysis could not be made but the harmonic mean of the two larger moments of inertia appears to lie between the limits 73.3 and 76.6×10^—40 g cm^2. The hydroxyl hydrogen does not rotate freely and indeed its torsional oscillation appears not to have a very low frequency. It is not possible to locate this hydrogen uniquely until other parameters of the molecule have been determined by electron diffraction. The possible effect of resonance on the O [Single Bond] H frequency is discussed

Structure of the O[Single Bond]H Bands in the Vapors of Halogen Substituted Alcohols

In the study of the infra-red absorption of organic substances containing hydroxyl groups it has been found that the O-H bands sometimes occur as multiplets even though only one such group is present per molecule. This has been observed both in the spectra of vapors (1) and of solutions (2,3) though in the latter case less structure is resolvable in some instances. The phenomenon has been explained by saying that the hydroxyl hydrogen is not free to rotate around the C-O bond, but may be found in more than one position of potential minimum in which the O-H frequency may be somewhat different (1,4). Though this explanation appears plausible it has seemed desirable to investigate the matter further by a quantitative study of some relatively simple substances in the vapor phase. Consequently a series of halogen substituted alcohols has been investigated with interesting results

The Separation of the Two Types of Iodine Molecule and the Photochemical Reaction of Gaseous Iodine with Hexene

Soon after Dennison had deduced from the specific-heat curve that ordinary hydrogen gas consists of a mixture of two types of molecule, the so called ortho and para hydrogen, a similar state of affairs in the case of iodine gas was demonstrated by direct experiment by R. W. Wood and F. W. Loomis (1). In brief, these experimenters found that the iodine bands observed in fluorescence stimulated by white light differ from those in the fluorescence excited by the green mercury line λ 5461, which happens to coincide with one of the iodine absorption lines. Half of the lines are missing in the latter case, only those being present which are due to transitions in which the rotational quantum number of the upper state is an even integer. In other words, in the fluorescence spectrum excited by λ 5461 only those lines appear which are due to what we may provisionally call the "ortho" type of iodine molecule. It is evident than that by irradiating iodine gas with the green mercury line it is possible to selectively activate molecules of the "ortho" type. Furthermore, as shown by these experiments, a molecule of the "ortho" type has an average life time in this form longer than the time it remains in the activated condition before emitting radiation. It occurred to one of us that these facts might be made use of in effecting a separation of the two molecular types. If some substance is added to the iodine gas with which only the activated molecules will react, one should be able to get rid of them, leaving only the other type of molecule which does not absorb the mercury line

The N[Single Bond]H Harmonic Bands of Pyrrole at lambda9900, and the Structure of the Pyrrole Molecule

In their study of the infra-red absorption of organic substances in carbon tetrachloride solution Wulf and Liddell (1) found that the strong second harmonic N-H band of pyrrole is accompanied by a weak satellite which lies approximately 50 cm^-1 to the long wave side and has roughly one-twentieth the intensity of the main band. The main band has been attributed by Pauling (2) to a planar pyrrole molecule and the weak satellite to a second molecular species in which the imino hydrogen lies out of the plane of the other atoms

QCD corrections to the hadronic production of a heavy quark pair and a W-boson including decay correlations

We perform an analytic calculation of the one-loop amplitude for the W-boson mediated process 0 \to d u-bar Q Q-bar l-bar l, retaining the mass for the quark Q. The momentum of each of the massive quarks is expressed as the sum of two massless momenta and the corresponding heavy quark spinor is expressed as a sum of two massless spinors. Using a special choice for the heavy quark spinors we obtain analytic expressions for the one-loop amplitudes which are amenable to fast numerical evaluation. The full next-to-leading order (NLO) calculation of hadron+hadron \to W(\to e nu) b b-bar with massive b-quarks is included in the program MCFM. A comparison is performed with previous published work.Comment: 45 pages, 17 figure

A Predictive Algorithm For Wetlands In Deep Time Paleoclimate Models

Methane is a powerful greenhouse gas produced in wetland environments via microbial action in anaerobic conditions. If the location and extent of wetlands are unknown, such as for the Earth many millions of years in the past, a model of wetland fraction is required in order to calculate methane emissions and thus help reduce uncertainty in the understanding of past warm greenhouse climates. Here we present an algorithm for predicting inundated wetland fraction for use in calculating wetland methane emission fluxes in deep time paleoclimate simulations. The algorithm determines, for each grid cell in a given paleoclimate simulation, the wetland fraction predicted by a nearest neighbours search of modern day data in a space described by a set of environmental, climate and vegetation variables. To explore this approach, we first test it for a modern day climate with variables obtained from observations and then for an Eocene climate with variables derived from a fully coupled global climate model (HadCM3BL-M2.2). Two independent dynamic vegetation models were used to provide two sets of equivalent vegetation variables which yielded two different wetland predictions. As a first test the method, using both vegetation models, satisfactorily reproduces modern data wetland fraction at a course grid resolution, similar to those used in paleoclimate simulations. We then applied the method to an early Eocene climate, testing its outputs against the locations of Eocene coal deposits. We predict global mean monthly wetland fraction area for the early Eocene of 8 to 10 × 106km2 with corresponding total annual methane flux of 656 to 909 Tg, depending on which of two different dynamic global vegetation models are used to model wetland fraction and methane emission rates. Both values are significantly higher than estimates for the modern-day of 4 × 106km2 and around 190Tg (Poulter et. al. 2017, Melton et. al., 2013

A Reinvestigation of the Vibration Spectrum of Ozone

Several analyses of the vibration spectrum of ozone have been proposed in recent years, all of which have been open to serious objection. Either they have failed to account for the observed structure of all the infrared bands, or if consistent with this structure have required an acute angled molecular model which is not in accord with the structure determination by electron diffraction. These difficulties appear to have resulted in part from some misconceptions regarding the relative intensities of the ozone bands, but chiefly from the previous failure to recognize the fundamental band of the vibration v_1

The Band Envelopes of Unsymmetrical Rotator Molecules. I. Calculation of the Theoretical Envelopes

Since the majority of molecules of chemical interest are too heavy to permit resolution of the rotational structure of the infra-red bands, it is of interest to find what information can be derived from a study of the band envelopes. Considerations of the type which Gerhard and Dennison have made for symmetrical molecules have been extended to the unsymmetrical rotator. By the use of an approximation method the envelopes of the three elementary types of band have been calculated for nine different sets of molecular parameters

The Photochemical Decomposition of Nitric Oxide by Absorption in the (0,0) and (1,0) γ Bands

The abnormally large pressure broadening observed in the γ bands of NO was interpreted by Wulf as indicating a pressure-induced predissociation of the upper electronic state (A^2 Σ)