Trapped Electrons and Radicals in γ-Irradiated Propylene Carbonate Glasses

1972 ◽  
Vol 50 (6) ◽  
pp. 782-791 ◽  
Author(s):  
Eric A. Shaede
Keyword(s):  
New Species ◽  
Absorption Band ◽  
Propylene Carbonate ◽  
Radical Anion ◽  
The Other ◽  
Γ Irradiation ◽  
Absorption Bands ◽  
Trapped Electrons ◽  
Optical Absorption Band ◽  
Positive Ions

Radicals formed by γ-irradiation of propylene carbonate (PC) glasses at 77 °K were studied by e.s.r. and optical spectroscopy. Trapped electrons were identified by their narrow (ΔHms = 4.5 G) Gaussian e.s.r. line at g = 2.0028 which was completely resolved from the radical spectrum. The trapped electrons were unstable at 77 °K. They decayed fairly rapidly via a process exhibiting non-homogeneous kinetics believed to be reaction with positive ions. The temperature dependence of the e.s.r. spectra of the other radicals formed is discussed although conclusive assignment of the lines could not be made.Ultraviolet photolysis of the radicals in the irradiated PC glasses produced new species identified as HCO, CO3−, and CH3 by their characteristic e.s.r. spectra. In addition, a complex optical absorption band in the 500–750 nm region was assigned to a combination of the absorption bands of the CO3− radical anion and the HCO radical.

scholarly journals A Photoelectric Hygrometer*

1947 ◽  
Vol 28 (7) ◽  
pp. 330-334 ◽  
Author(s):  
Bernard Hamermesh ◽  
Frederick Reines ◽  
Serge A. Korff
Keyword(s):  
Water Vapor ◽  
Absorption Band ◽  
Absolute Humidity ◽  
Precipitable Water ◽  
The Other ◽  
Water Vapor Absorption ◽  
Absorption Bands ◽  
Vapor Absorption ◽  
Dispersing System ◽  
Humidity Range

An instrument that measures small absolute humidity changes by the photoelectric examination of the 9,440 Ångstrom-units absorption band of water vapor is described. The instrument consists of a small source of light which sends its radiation over an air path of less than one and a half meters to a dispersing system. The resulting spectrum then is allowed to fall on two vacuum phototubes; one centered in the 9,400 Ångstrom-units absorption band of water vapor, the other located at 8,000 ngstrom units where no water vapor absorption bands exist. As the absolute humidity in the air path is varied, the phototube in the region of the band is affected; whereas the reference phototube is not. The phototubes are arranged in an amplifying circuit so as to magnify the effect of varying humidity. The instrument uses a portable microammeter instead of the sensitive galvanometer of all previous spectral hygrometers. Humidity changes of 2 to 8 × 10−5 centimeter of precipitable water path over 143 centimeters of air path can be measured. An investigation of the small sensitive range of the instrument was carried out and the results indicate that the device is confined to use over a small humidity range with equipment available at the present time.

The Optical Properties of ION Implanted Silica

1997 ◽  
Vol 504 ◽  
Author(s):  
C. C. Smith ◽  
D. Ila ◽  
E. K. Williams ◽  
D. B. Poker ◽  
D. K. Hensley
Keyword(s):  
Optical Properties ◽  
Absorption Band ◽  
Optical Absorption ◽  
Electron Microscopic ◽  
Absorption Bands ◽  
Optical Absorption Band ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Before And After ◽  
Microscopic Techniques

ABSTRACTWe present the results of our investigation of the change in the optical properties of silica, "suprasil", after keV through MeV implantation of copper, tin, silver and gold and after annealing. Suprasil, name brand of silica glass produced by Hereaus Amersil, which is chemically highly pure with well known optical properties. Both linear and nonlinear optical properties of the implanted silica were investigated before and after thermal annealing. All implants showed strong optical absorption bands in agreement with Mie theory. For implants with a measurable optical absorption band we used Doyle's theory and the full width half maximum of the absorption band to calculate the predicted size of the formed nanoclusters at various heat treatment temperatures. These results are compared with those obtained from direct observation using transmission electron microscopic techniques.

First Nano-Infrared Spectroscopy and Imaging Measurements of Single Phospholipid Bilayers

2018 ◽  
Author(s):  
Adrian Cernescu ◽  
Michał Szuwarzyński ◽  
Urszula Kwolek ◽  
Karol Wolski ◽  
Paweł Wydro ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Ir Spectroscopy ◽  
Absorption Band ◽  
Spectral Region ◽  
Near Field ◽  
Phospholipid Bilayers ◽  
Model Systems ◽  
Absorption Bands ◽  
Protein Complement ◽  
20 Nm

<div><div>Scattering-mode Scanning Near-Field Optical Microscopy (sSNOM) allows one to obtain absorption spectra in the mid-IR region for samples as small as 20 nm in size. This configuration has made it possible to measure FTIR spectra of the protein complement of membranes. (Amenabar 2013) We now show that mid-IR sSNOM has the sensitivity required to measure spectra of phospholipids in individual bilayers in the spectral range 800 cm<sup>-1</sup>–1400 cm<sup>-1</sup>. We have observed the main absorption bands of the dipalmitoylphosphatidylcholine headgroups in this spectral region above noise level. We have also mapped the phosphate absorption band at 1070 cm<sup>-1</sup> simultaneously with the AFM topography. We have shown that we could achieve sufficient contrast to discriminate between single and multiple phospholipid bilayers and other structures, such as liposomes. This work opens the way to further research that uses nano-IR spectroscopy to describe the biochemistry of cell membranes and model systems.</div></div><div></div>

Problems of species and the features of geographical distribution in colonial volvocine algae (Chlorophyta)

2020 ◽  
Vol 54 (2) ◽  
pp. 299-311
Author(s):  
A. G. Desnitskiy
Keyword(s):  
New Species ◽  
Geographical Distribution ◽  
World Literature ◽  
The Other ◽  
Disjunct Distribution ◽  
Published Data ◽  
Species Problem ◽  
Comprehensive Review ◽  
Volvocine Algae ◽  
Cryptic Taxa

More than ten new species of colonial volvocine algae were described in world literature during recent years. In present review, the published data on taxonomy, geographical distribution and the species problem in this group of algae, mainly from the genera Gonium, Pandorina, Eudorina, and Volvox, are critically discussed. There are both cosmopolitan volvocalean species and species with local or disjunct distribution. On the other hand, the description of new cryptic taxa in some genera of the colonial family Volvocaceae, such as Pandorina and Volvox, complicates the preparation of a comprehensive review on their geography.

scholarly journals Discovery of the Smallest Lace Bug from Mid-Cretaceous of Northern Myanmar Supports the Hypothesis of a Miniaturization Phenomenon of Insects in Kachin Amber (Hemiptera: Heteroptera: Tingidae)

Taxonomy ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 60-68
Author(s):  
Jun Souma ◽  
Shûhei Yamamoto ◽  
Yui Takahashi
Keyword(s):  
New Species ◽  
New Genus ◽  
The Other ◽  
Diagnostic Characters ◽  
Lace Bug ◽  
New Finding ◽  
A New Species

A total of 14 species in seven tingid genera have been described from the mid-Cretaceous Burmese (Kachin) amber from northern Myanmar, with very distinct paleofauna. Here, a new species of a new genus, Burmavianaida anomalocapitata gen. et sp. nov., is described from Kachin amber. This new species can be readily distinguished from the other described tingid taxa by the apparently smaller body and the structures of the pronotum and hemelytron. Burmavianaida gen. nov. shares the diagnostic characters with two clades composed of three extant subfamilies (Cantacaderinae + Tinginae) and Vianaidinae and may represent an extinct clade distinct from them. To the best of our knowledge, B. anomalocapitata sp. nov. is the smallest species of Tingidae among over 2600 described species. Our new finding supports the hypothesis of the miniaturization phenomenon of insects in Kachin amber, as suggested by previous studies.

scholarly journals Camelina neglecta (Brassicaceae, Camelineae), a new diploid species from Europe

PhytoKeys ◽  
2019 ◽  
Vol 115 ◽  
pp. 51-57 ◽  
Author(s):  
Jordan R. Brock ◽  
Terezie Mandáková ◽  
Martin A. Lysak ◽  
Ihsan A. Al-Shehbaz
Keyword(s):  
New Species ◽  
Diploid Species ◽  
The Other

Camelinaneglecta is described as a new diploid species and its relationship to the other diploids of the genus and to the somewhat superficially similar tetraploid C.rumelica and hexaploid C.microcarpa, are discussed. SEM of seed and stem trichomes of the new species are presented.

The Leptobrachium (Anura: Megophryidae) of the Langbian Plateau, southern Vietnam, with description of a new species

Zootaxa ◽  
2011 ◽  
Vol 2804 (1) ◽  
pp. 25 ◽  
Author(s):  
BRYAN L. STUART ◽  
JODI J. L. ROWLEY ◽  
DAO THI ANH TRAN ◽  
DUONG THI THUY LE ◽  
HUY DUC HOANG
Keyword(s):  
Mitochondrial Dna ◽  
New Species ◽  
Small Body ◽  
Original Description ◽  
The Other ◽  
Sexually Active ◽  
Small Body Size ◽  
Upper Lip ◽  
Southern Vietnam ◽  
A New Species

We sampled two forms of Leptobrachium in syntopy at the type locality of L. pullum at upper elevations on the Langbian Plateau, southern Vietnam. The two forms differed in morphology (primarily in coloration), mitochondrial DNA, and male advertisement calls. One form closely agrees with the type series of L. pullum (but not to its original description due to error), and the other is described as new. Leptobrachium leucops sp. nov. is distinguished from its congeners by having small body size (males with SVL 38.8–45.2), the upper one-third to one-half of iris white, a blue scleral arc, a dark venter, and sexually active males without spines on the upper lip. Leptobrachium pullum and L. mouhoti, a recently described species from low-elevation slopes of the Langbian Plateau in eastern Cambodia, are morphologically divergent but genetically similar, warranting further investigation into geographic variation in the red-eyed Leptobrachium of southern Indochina.

Two new species of Terebrasabella (Annelida: Sabellidae: Sabellinae) from Australia

Zootaxa ◽  
2007 ◽  
Vol 1434 (1) ◽  
pp. 51 ◽  
Author(s):  
ANNA MURRAY ◽  
GREG W. ROUSE
Keyword(s):  
New Species ◽  
The Other ◽  
Barrier Reef ◽  
Lizard Island ◽  
Eastern Australia ◽  
Two New Species ◽  
Coral Rock

Two new species of Terebrasabella Fitzhugh & Rouse, 1999 are described from eastern Australia. Terebrasabella hutchingsae sp. nov., was found from preserved coral rock debris collected in 1977 on the outer Barrier Reef near Lizard Island, Queensland. Terebrasabella fitzhughi sp. nov., was found alive in burrows in and among spirorbin serpulid tubes on intertidal rocks in Tasmania in 1996. Both species were found in mucoid tubes, and brood their young in a manner similar to the only other described species of Terebrasabella, T. heterouncinata Fitzhugh & Rouse, 1999. Terebrasabella hutchingsae sp. nov., is exceptional as it possesses a type of thoracic neurochaetal uncinus different from the other two species, and which is similar to the notochaetal acicular “palmate hook” seen in Caobangia. Descriptions of both species are given, and the diagnosis for Terebrasabella is emended. Larval and chaetal morphology and relationships among of the three known Terebrasabella spp. are discussed.

Upretia squamulosa, a new lichen species from the arid valley of Jinsha-jiang River, China

Phytotaxa ◽  
2019 ◽  
Vol 402 (6) ◽  
pp. 288
Author(s):  
YAN YUN ZHANG ◽  
XIN YU WANG ◽  
LI JUAN LI ◽  
ULRIK SØCHTING ◽  
AN CHENG YIN ◽  
...  
Keyword(s):  
New Species ◽  
Phylogenetic Tree ◽  
Lichen Species ◽  
The Other

Upretia squamulosa is described as new to science from the arid valley of Jinsha-jiang River, China. It is characterized by a squamulose thallus, greyish green to brown upper surface, lecanorine apothecia, and by containing gyrophoric and lecanoric acids. The other species in the genus, U. amarkantakana, differs from the new species by the crustose to subsquamulose thallus with lobate margin and the absence of gyrophoric and lecanoric acids. A phylogenetic tree based on nrITS for Upretia and related genera in the subfamily Caloplacoideae is established to assess the affinities of the new species.

TWO NEW SPECIES OF ORTHEZIA

1898 ◽  
Vol 30 (1) ◽  
pp. 12-14 ◽  
Author(s):  
J. D. Tinsley
Keyword(s):  
New Species ◽  
The Other ◽  
Lateral Margin ◽  
Two New Species ◽  
Marginal Plates ◽  
Lateral Plates

Orthezia cheilanthi, n. sp.—Adult ♀ Length, 3.5 mm. Width, 3-3.5 mm. Length + ovisac, 6-8 mm. Width of Ovisac 3-4 mm. Body above covered with whtie secretion, which forms lateral and sub. dorsal longitudinal keels. A well-defined subdorsal furrow between the keels and the lateral margin formed by 3 or more rows of paltes; these are smaller than the projecting marginal plates, which are flattened; caudal plate and the 3 or 4 plates on each side of it very little longer than the lateral plates. The structure of the secretion is compact; in most of the other species of Orthezia it is fluffy.

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