Spatial and Electronic Structure of the Pyrene Molecule, Tripaflavin Cation and Eosin Anions As a Prerequisite for Interpreting Their Solid-phase Fluorescence

2016 ◽  
Vol 16 (4) ◽  
pp. 393-398
Author(s):  
A. N. Pankratov ◽  
◽  
I. M. Uchaeva ◽  
S. M. Rogacheva ◽  
E. V. Volkova ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Solid Phase ◽  
Pyrene Molecule

Computational studies of energetics, electronic structure, and vibrational spectra of PETN nanoparticles

2021 ◽  
Vol 99 (1) ◽  
pp. 63-71
Author(s):  
Qiannan Ma ◽  
Weihua Zhu
Keyword(s):  
Electronic Structure ◽  
Vibrational Spectra ◽  
Density Functional ◽  
Solid Phase ◽  
Tight Binding ◽  
High Energy ◽  
Pentaerythritol Tetranitrate ◽  
Energy Bands ◽  
Extra Energy ◽  
The Stability

The density functional tight binding method was used to explore the energetics, electronic structure, and vibrational spectra of pentaerythritol tetranitrate (PETN) nanoparticles (NPs). The surface energy of the PETN NP is anisotropic and its extra energy decreases with the increase of size. The energy bands of the NPs are significantly expanded and the band gaps are narrowed, thus reducing the stability due to nanometer size effect. The surface of the NP is mainly covered by the NO2 group. The high-energy surface may play a role in triggering chemical decomposition. The vibration frequencies of the PETN NPs present a wider distribution than those of the gas and solid phase PETN, which will increase the probability of energy transfer to the molecules in the system and promote the decomposition of PETN. Our results provide a basic understanding from a molecular perspective to the energy properties of nano explosives.

Electronic structure of titanium(III) and titanium(IV) halides studied by solid-phase x-ray photoelectron spectroscopy

1987 ◽  
Vol 26 (8) ◽  
pp. 1212-1217 ◽  
Author(s):  
Christine Mousty-Desbuquoit ◽  
Joseph Riga ◽  
Jacques J. Verbist
Keyword(s):  
Electronic Structure ◽  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
X Ray

Solid-phase immunoelectron microscopy for rapid diagnosis of enteroviruses

1984 ◽  
Vol 42 ◽  
pp. 226-227 ◽  
Author(s):  
K. Pegg-Feige ◽  
F. W. Doane
Keyword(s):  
Electron Microscopy ◽  
Cell Culture ◽  
Immunoelectron Microscopy ◽  
Detection Method ◽  
Solid Phase ◽  
Protein A ◽  
Plant Viruses ◽  
Rapid Diagnosis ◽  
Virus Diagnosis ◽  
Antiviral Antibody

Immunoelectron microscopy (IEM) applied to rapid virus diagnosis offers a more sensitive detection method than direct electron microscopy (DEM), and can also be used to serotype viruses. One of several IEM techniques is that introduced by Derrick in 1972, in which antiviral antibody is attached to the support film of an EM specimen grid. Originally developed for plant viruses, it has recently been applied to several animal viruses, especially rotaviruses. We have investigated the use of this solid phase IEM technique (SPIEM) in detecting and identifying enteroviruses (in the form of crude cell culture isolates), and have compared it with a modified “SPIEM-SPA” method in which grids are coated with protein A from Staphylococcus aureus prior to exposure to antiserum.

Application of solid-phase immune electron microscopy to study physical and stability characteristics of enterically transmitted non-a, non-b hepatitis virus

1988 ◽  
Vol 46 ◽  
pp. 80-81
Author(s):  
Charles D. Humphrey ◽  
E. H. Cook ◽  
Karen A. McCaustland ◽  
Daniel W. Bradley
Keyword(s):  
Electron Microscopy ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Etiologic Agent ◽  
World Health ◽  
Health Concern ◽  
Morphological Identification ◽  
Immune Electron Microscopy

Enterically transmitted non-A, non-B hepatitis (ET-NANBH) is a type of hepatitis which is increasingly becoming a significant world health concern. As with hepatitis A virus (HAV), spread is by the fecal-oral mode of transmission. Until recently, the etiologic agent had not been isolated and identified. We have succeeded in the isolation and preliminary characterization of this virus and demonstrating that this agent can cause hepatic disease and seroconversion in experimental primates. Our characterization of this virus was facilitated by immune (IEM) and solid phase immune electron microscopic (SPIEM) methodologies.Many immune electron microscopy methodologies have been used for morphological identification and characterization of viruses. We have previously reported a highly effective solid phase immune electron microscopy procedure which facilitated identification of hepatitis A virus (HAV) in crude cell culture extracts. More recently we have reported utilization of the method for identification of an etiologic agent responsible for (ET-NANBH).

Identification of hepatitis a virus in cell cultures by solid phase immune electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 238-239
Author(s):  
C.D. Humphrey ◽  
T.L. Cromeans ◽  
E.H. Cook ◽  
D.W. Bradley
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Cell Cultures ◽  
Rapid Detection ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Immune Electron Microscopy ◽  
Detection And Identification

There is a variety of methods available for the rapid detection and identification of viruses by electron microscopy as described in several reviews. The predominant techniques are classified as direct electron microscopy (DEM), immune electron microscopy (IEM), liquid phase immune electron microscopy (LPIEM) and solid phase immune electron microscopy (SPIEM). Each technique has inherent strengths and weaknesses. However, in recent years, the most progress for identifying viruses has been realized by the utilization of SPIEM.

Dynamic studies of silicide-mediated crystallization of amorphous silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1352-1353
Author(s):  
C. Hayzelden ◽  
J. L. Batstone
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Metallic Phase ◽  
Single Crystal Substrate ◽  
Free Electrons ◽  
Melt Temperature ◽  
Transmission Electron ◽  
Crystal Substrate ◽  
High Resolution Tem

Epitaxial reordering of amorphous Si(a-Si) on an underlying single-crystal substrate occurs well below the melt temperature by the process of solid phase epitaxial growth (SPEG). Growth of crystalline Si(c-Si) is known to be enhanced by the presence of small amounts of a metallic phase, presumably due to an interaction of the free electrons of the metal with the covalent Si bonds near the growing interface. Ion implantation of Ni was shown to lower the crystallization temperature of an a-Si thin film by approximately 200°C. Using in situ transmission electron microscopy (TEM), precipitates of NiSi2 formed within the a-Si film during annealing, were observed to migrate, leaving a trail of epitaxial c-Si. High resolution TEM revealed an epitaxial NiSi2/Si(l11) interface which was Type A. We discuss here the enhanced nucleation of c-Si and subsequent silicide-mediated SPEG of Ni-implanted a-Si.Thin films of a-Si, 950 Å thick, were deposited onto Si(100) wafers capped with 1000Å of a-SiO2. Ion implantation produced sharply peaked Ni concentrations of 4×l020 and 2×l021 ions cm−3, in the center of the films.

EELS Measurement of the Local Electronic Structure of Copper Atoms Segregated to Aluminum Grain Boundaries

1996 ◽  
Vol 54 ◽  
pp. 342-343
Author(s):  
S.J. Splinter ◽  
J. Bruley ◽  
P.E. Batson ◽  
D.A. Smith ◽  
R. Rosenberg
Keyword(s):  
Electronic Structure ◽  
Grain Boundaries ◽  
Boundary Segregation ◽  
Thin Layers ◽  
Nominal Composition ◽  
Spatially Resolved ◽  
Service Lifetime ◽  
Heat Treated ◽  
Probe Size ◽  
Local Electronic Structure

It has long been known that the addition of Cu to Al interconnects improves the resistance to electromigration failure. It is generally accepted that this improvement is the result of Cu segregation to Al grain boundaries. The exact mechanism by which segregated Cu increases service lifetime is not understood, although it has been suggested that the formation of thin layers of θ-CuA12 (or some metastable substoichiometric precursor, θ’ or θ”) at the boundaries may be necessary. This paper reports measurements of the local electronic structure of Cu atoms segregated to Al grain boundaries using spatially resolved EELS in a UHV STEM. It is shown that segregated Cu exists in a chemical environment similar to that of Cu atoms in bulk θ-phase precipitates.Films of 100 nm thickness and nominal composition Al-2.5wt%Cu were deposited by sputtering from alloy targets onto NaCl substrates. The samples were solution heat treated at 748K for 30 min and aged at 523K for 4 h to promote equilibrium grain boundary segregation. EELS measurements were made using a Gatan 666 PEELS spectrometer interfaced to a VG HB501 STEM operating at 100 keV. The probe size was estimated to be 1 nm FWHM. Grain boundaries with the narrowest projected width were chosen for analysis. EDX measurements of Cu segregation were made using a VG HB603 STEM.

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