Combined High Resolution UV and Microwave Results: Structure of the Benzonitrile•Water Complex

1997 ◽  
Vol 52 (8-9) ◽  
pp. 655-664 ◽  
Author(s):  
R. M. Helm ◽  
H.-P. Vogel ◽  
H. J. Neusser ◽  
V. Storm ◽  
D. Consalvo ◽  
...  
Keyword(s):  
High Resolution ◽  
Uv Spectra ◽  
Line Broadening ◽  
Additional Information ◽  
Two Photon ◽  
Structure Changes ◽  
Quadrupole Coupling ◽  
Photon Ionization ◽  
Nuclear Quadrupole ◽  
First Time

Abstract High resolution ultraviolet (UV) and molecular beam Fourier transform microwave (MB FTMW) spectroscopy of the benzonitrile·water (BZNW) cluster were performed to measure cluster structures in the S0 and S1 states. The MW experiments provide additional information on the structure and the 14N-nuclear quadrupole coupling in the ground state So, the UV experiments on the dynamics in Si. The rotationally resolved sub-Doppler UV spectra of BZNW were measured by mass-selective resonance-enhanced two-photon ionization. For the first time this UV technique has been applied to hydrogen-bonded clusters. From the UV spectra the rotational constants are obtained by Correlation Automated Rotational Fitting. The MW spectra were analyzed with the model of a centrifugally distorted rotor including nuclear quadrupole coupling. A r0 -fit of the water position within the cluster is performed. The water is found to be located with its oxygen nearly in the plane of benzonitrile (BZN). For S0 (S1), the distance of the oxygen to the ortho hydrogen is r0 = 2.477(4) Å (2.457(2) Å) and the angle to the ortho carbon-hydrogen bond 143.34(2)° (141.91(3)°). The structure differences in S1 and S0 can be explained by the structure changes of the BZN molecule. A line broadening, which points to a faster decay in Si upon clustering with the polar solvent, is observed for the BZNW cluster.

scholarly journals Deuterium Quadrupole Coupling Constants of Deuterohalogenoacetylens

1988 ◽  
Vol 43 (8-9) ◽  
pp. 755-757 ◽  
Author(s):  
N. Heineking ◽  
M. Andolfatto ◽  
C. Kruse ◽  
W. Eberstein ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Fourier Transform Spectroscopy ◽  
Spin Rotation ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Rotational Transitions

Abstract Employing the high resolution of microwave Fourier transform spectroscopy, we investigated the lowest rotational transitions of fluoro-, bromo-, and iodoacetylene-d. Along with the rotational, centrifugal distortion, halogen nuclear quadrupole, and halogen spin-rotation coupling constants, we determined the deuterium quadrupole coupling constants of bromo-and iodoacetylene-d. For fluoroacetylene-d, we redetermined the deuterium nuclear quadrupole coupling constants with higher accuracy.

Stonehenge, Wiltshire, UK: High Resolution Geophysical Surveys in the Surrounding Landscape, 2011

2013 ◽  
Vol 16 (1) ◽  
pp. 63-93 ◽  
Author(s):  
Timothy Darvill ◽  
Friedrich Lüth ◽  
Knut Rassmann ◽  
Andreas Fischer ◽  
Kay Winkelmann
Keyword(s):  
High Resolution ◽  
East Side ◽  
The West ◽  
Additional Information ◽  
The North ◽  
Geophysical Surveys ◽  
Surrounding Landscape ◽  
First Time ◽  
Southern Section ◽  
Management Issues

An extensive high-resolution geophysical survey covering 2 km2was undertaken to the north of Stonehenge in June and October 2011. The survey is important in providing, for the first time, abundant detail on the form and structure of the Stonehenge Cursus, including the recognition of entrances in both of the long sides. Much additional information about the internal form of round barrows in the Cursus Round Barrow Cemetery, the course of the Avenue, the course of the so-called Gate Ditch, and numerous tracks and early roads crossing the landscape was recorded. A series of previously unrecognized features were identified: a pit-arc or cove below a barrow on the west side of King Barrow Ridge, a square-shaped feature surrounded by pits on the east side of Stonehenge Bottom, and a linear ditch on the same solstical axis, and parallel to, the southern section of the Stonehenge Avenue. An extensive scatter of small metallic anomalies marking the position of camping grounds associated with the Stonehenge Free Festival in the late 1970s and early 1980s raise interesting conservation and management issues.

14N Nuclear Quadrupole Hyperfine Structure in the Microwave Spectrum of Methyl Azide, CH3N3

1989 ◽  
Vol 44 (7) ◽  
pp. 669-674 ◽  
Author(s):  
N. Heineking ◽  
M.C.L. Gerry
Keyword(s):  
Hyperfine Structure ◽  
Ab Initio Calculation ◽  
Structural Information ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
First Time

Abstract The 14N nuclear quadrupole hyperfine structure in the rotational spectra of three isotopic species of methyl azide, CH3 14N3, CH3 15N14N2, and CH3 14N2 15N, has been resolved using microwave Fourier transform spectroscopy. The quadrupole coupling constants of 14N at all three positions have been evaluated and are compared with those from an ab initio calculation in the literature.Since the spectra of the substituted species have been obtained for the first time, they have provided new structural information: the rotational constants are consistent with a structure in which the NNN chain is slightly bent.

scholarly journals Automated quantification of synaptic boutons reveals their 3D distribution in the honey bee mushroom body

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Amélie Cabirol ◽  
Albrecht Haase
Keyword(s):  
Mushroom Body ◽  
Automated Analysis ◽  
Average Density ◽  
Additional Information ◽  
Two Photon ◽  
Automated Method ◽  
Automated Quantification ◽  
Multiple Threshold ◽  
Synaptic Boutons ◽  
First Time

AbstractSynaptic boutons are highly plastic structures undergoing experience-dependent changes in their number, volume, and shape. Their plasticity has been intensively studied in the insect mushroom bodies by manually counting the number of boutons in small regions of interest and extrapolating this number to the volume of the mushroom body neuropil. Here we extend this analysis to the synaptic bouton distribution within a larger subregion of the mushroom body olfactory neuropil of honey bees (Apis mellifera). This required the development of an automated method combining two-photon imaging with advanced image post-processing and multiple threshold segmentation. The method was first validated in subregions of the mushroom body olfactory and visual neuropils. Further analyses in the olfactory neuropil suggested that previous studies overestimated the number of synaptic boutons. As a reason for that, we identified boundaries effects in the small volume samples. The application of the automated analysis to larger volumes of the mushroom body olfactory neuropil revealed a corrected average density of synaptic boutons and, for the first time, their 3D spatial distribution. This distribution exhibited a considerable heterogeneity. This additional information on the synaptic bouton distribution provides the basis for future studies on brain development, symmetry, and plasticity.

High-resolution UV spectroscopy of vibronic bands in p-difluorobenzene and p-difluorobenzene–Ar: The role of Herzberg–Teller coupling

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1179-1186 ◽  
Author(s):  
R. Sussmann ◽  
R. Neuhauser ◽  
H. J. Neusser
Keyword(s):  
High Resolution ◽  
Electronic Excitation ◽  
Uv Spectroscopy ◽  
Van Der Waals ◽  
Rotational Structure ◽  
Moments Of Inertia ◽  
Van Der Waals Complex ◽  
Two Photon ◽  
Photon Ionization

Rotationally resolved spectra of two bands in the S1 → S0 transition of the p-difluorobenzene molecule and its van der Waals complex with Ar have been measured by mass-selective resonance-enhanced two-photon ionization. The rotational structure of the 000 and the 2710 bands in the monomer as well as in the complex differ from each other. They can be theoretically reproduced assuming a transition moment oriented along the short in-plane axis of the molecule in the case of the 000 transition and the long in-plane axis in the case of the 2710 transition. Since the magnitude of the moments of inertia is changed in the complex by adding an Ar atom, complexation leads to a change of rotational structures of the same band. The analysis of the rotational structure points to Herzberg–Teller coupling by vibronic interaction with the S2 (1B1u) state as the mechanism responsible for the appearance of the 2710 band. The rotational constants determined from a fit of the spectra yield an effective van der Waals distance of 3.55 (2) Å (1 Å = 10−10 m) of the Ar atom from the p-difluorobenzene plane, which decreases by 0.06 Å on electronic excitation to the S1 state.

ABSORPTION-LINE BROADENING IN BORON-DOPED SILICON

1967 ◽  
Vol 45 (8) ◽  
pp. 2797-2804 ◽  
Author(s):  
J. J. White
Keyword(s):  
Absorption Line ◽  
Excited States ◽  
Half Width ◽  
Line Broadening ◽  
Additional Information ◽  
Boron Doped ◽  
Doped Silicon ◽  
Time Part ◽  
Width Measurements ◽  
First Time

In boron-doped silicon, the excitation of bound holes from the acceptor ground state to the excited states leads to an infrared absorption-line spectrum. In a recent half-width study of the boron absorption lines, Colbow (1963) separated the various line-broadening contributions for the first time. Part of Colbow's half-widths is now found to be due to external strains introduced by the sample mounting. New half-width measurements of "strain-free" mounted boron-doped silicon are presented, Colbow's work is corrected, and additional information regarding the various broadening contributions is given.

scholarly journals A FUSE View of Winds from the Central Stars of Planetary Nebulae

2010 ◽  
Vol 27 (2) ◽  
pp. 210-213 ◽  
Author(s):  
Martín A. Guerrero ◽  
Gerardo Ramos-Larios ◽  
Derck Massa
Keyword(s):  
High Resolution ◽  
Systematic Study ◽  
Spectral Resolution ◽  
Preliminary Analysis ◽  
Planetary Nebulae ◽  
Uv Spectra ◽  
High Spectral Resolution ◽  
Stellar Winds ◽  
First Time ◽  
Central Stars

AbstractSince the IUE satellite produced a vast collection of high-resolution UV spectra of the central stars of planetary nebulae (CSPNe), there has not been any further systematic study of the stellar winds of these stars. The high spectral resolution, sensitivity and large number of archival observations in the FUSE archive allow the study of the stellar winds of CSPNe in the far-UV domain where lines of species spanning a wide excitation range can be observed. We present here a preliminary analysis of the P Cygni profiles of a sample of ∼60 CSPNe observed by FUSE. P Cygni profiles providing evidence for fast stellar winds with velocities between 200 and 4300 km s−1 have been found in 40 CSPNe. In many cases, this is the first time that fast stellar winds have been reported for these planetary nebulae (PNe). A detailed study of these far-UV spectra is on-going.

scholarly journals Automated quantification of synaptic boutons reveals their 3D distribution in the honey bee mushroom body

2019 ◽  
Author(s):  
Amélie Cabirol ◽  
Albrecht Haase
Keyword(s):  
Mushroom Body ◽  
Automated Analysis ◽  
Average Density ◽  
Additional Information ◽  
Two Photon ◽  
Automated Method ◽  
Automated Quantification ◽  
Multiple Threshold ◽  
Synaptic Boutons ◽  
First Time

AbstractSynaptic boutons are highly plastic structures undergoing experience-dependent changes in their number, volume, and shape. Their plasticity has been intensively studied in the insect mushroom bodies by manually counting the number of boutons in small regions of interest and extrapolating this number to the volume of the mushroom body neuropil.Here we extend this analysis to the synaptic bouton distribution within a larger subregion of the mushroom body olfactory neuropil of honey bees (Apis mellifera). This required the development of an automated method combining two-photon imaging with advanced image post-processing and multiple threshold segmentation. The method was first validated in subregions of the mushroom body olfactory and visual neuropils. Further analyses in the olfactory neuropil suggested that previous studies overestimated the number of synaptic boutons. As a reason for that, we identified boundaries effects in the small volume samples. The application of the automated analysis to larger volumes of the mushroom body olfactory neuropil revealed a corrected average density of synaptic boutons and, for the first time, their 3D spatial distribution. This distribution exhibited a considerable heterogeneity.This additional information on the synaptic bouton distribution provides the basis for future studies on brain development, symmetry, and plasticity.

The sulfur dioxide-hydrogen fluoride complex. Additional information to the experiment from ab initiocalculations

1988 ◽  
Vol 53 (9) ◽  
pp. 1989-1994 ◽  
Author(s):  
Stefan Gerber ◽  
Hanspeter Huber
Keyword(s):  
Experimental Data ◽  
Sulfur Dioxide ◽  
Hydrogen Fluoride ◽  
Quadrupole Coupling Constant ◽  
Title Complex ◽  
Coupling Constant ◽  
Additional Information ◽  
Nuclear Quadrupole Coupling Constant ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

The structure and D-nuclear quadrupole coupling constant of the title complex are calculated by ab initio SCF methods. The results are compared with recently published experimental data. The calculations yield additional information not amenable to the experiment.

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