1,973 research outputs found
Electron-Hole Asymmetry in Single-Walled Carbon Nanotubes Probed by Direct Observation of Transverse Quasi-Dark Excitons
We studied the asymmetry between valence and conduction bands in
single-walled carbon nanotubes (SWNTs) through the direct observation of
spin-singlet transverse dark excitons using polarized photoluminescence
excitation spectroscopy. The intrinsic electron-hole (e-h) asymmetry lifts the
degeneracy of the transverse exciton wavefunctions at two equivalent K and K'
valleys in momentum space, which gives finite oscillator strength to transverse
dark exciton states. Chirality-dependent spectral weight transfer to transverse
dark states was clearly observed, indicating that the degree of the e-h
asymmetry depends on the specific nanotube structure. Based on comparison
between theoretical and experimental results, we evaluated the band asymmetry
parameters in graphene and various carbon nanotube structures.Comment: 11 pages, 4 figure
Suppression of cell-spreading and phagocytic activity on nano-pillared surface: in vitro experiment using hemocytes of the colonial ascidian Botryllus schlosseri.
Nano-scale nipple array on the body surface has been described from various invertebrates including endoparasitic and mesoparasitic copepods, but the functions of the nipple array is not well understood. Using the hydrophilized nanopillar sheets made of polystyrene as a mimetic material of the nipple arrays on the parasites\u2019 body surface, we assayed the cell spreading and phagocytosis of the hemocytes of the colonial ascidian Botryllus schlosseri. On the pillared surface, the number of spreading amebocytes and the number of phagocytizing hemocytes per unit area were always smaller than those on the flat surface (Mann-Whitney test, p < 0.05 - 0.001), probably because the effective area for the cell attachment on the pillared surface is much smaller than the area on the flat sheet. The present results supports the idea that the nipple array on the parasites' body surface reduces the innate immune reaction from the host hemocytes
Financial Assessment Considered Weighting Factor Scenarios for the Optimal Combination of Power Plants on the Power System Operation
This paper presents an application of the novel evolutionary algorithm for assessing financially an economic power system operation throughout a combined economic and emission dispatch problem required by various technical limitations. In detail, this problem considers two dispatches for fuel and environmental aspects as a constrained objective function associated with weighting factor scenarios. Running out simulations show that minimum costs are depended on weighting factors, which implemented on the combination of the problem. Reducing the total fuel cost focused on the dispatching priority and the pollutant target based on the emission production have difference implications as its contribution to the economic operation, the increasing load demand leads to generated powers, costs and emission discharges associated with its parameters and power schedules
The Penetration of Pollutant Productions on Dynamic Generated Power Operations Optimized Using a Novel Evolutionary Algorithm
At Present, the environmental protection penetrates public awareness to decrease atmospheric emissions as important efforts for increasing living quality in air from various gaseous effects. Technically, it has forced industrial sectors to control pollutant productions while operating machineries of engineering processes to keep all materials for final products. It has also forced the power system operation to modify operational strategies of thermal power plants considered pollutant productions from combustions of fossil fuels for reducing emissions. Moreover, reasonable decisions are needed to schedule combinations of generating units for providing electric energy with less pollutant discharges and more economically operation. In particular, these strategies are required by operational conditions and technical constraints for optimizing the operating cost included decreasing pollutant productions. This paper demonstrates new approaches for measuring pollutant penetrations embedded in single priority function. Results obtained show that the computation has different performances for 24 hours of the operation. Moreover, emission discharges are dominated gradually by higher contributors associated with scheduled power plants as emission requirements
Formation of hydrogen peroxide and water from the reaction of cold hydrogen atoms with solid oxygen at 10K
The reactions of cold H atoms with solid O2 molecules were investigated at 10
K. The formation of H2O2 and H2O has been confirmed by in-situ infrared
spectroscopy. We found that the reaction proceeds very efficiently and obtained
the effective reaction rates. This is the first clear experimental evidence of
the formation of water molecules under conditions mimicking those found in cold
interstellar molecular clouds. Based on the experimental results, we discuss
the reaction mechanism and astrophysical implications.Comment: 12 pages, 3 Postscript figures, use package amsmath, amssymb,
graphic
The Study of Hydrogen Retention and Existence States in Boron Thin Film Exposed to Hydrogen Glow Discharge
Predictors of Gastric Neoplasia in Cases Negative for Helicobacter pylori Antibody and with Normal Pepsinogen
Photometric Properties of Kiso Ultraviolet-Excess Galaxies in the Lynx-Ursa Major Region
We have performed a systematic study of several regions in the sky where the
number of galaxies exhibiting star formation (SF) activity is greater than
average. We used Kiso ultraviolet-excess galaxies (KUGs) as our SF-enhanced
sample. By statistically comparing the KUG and non-KUG distributions, we
discovered four KUG-rich regions with a size of . One of these regions corresponds spatially to a filament of length
Mpc in the Lynx-Ursa Major region (). We call this ``the Lynx-Ursa
Major (LUM) filament''. We obtained surface photometry of 11 of
the KUGs in the LUM filament and used these to investigate the integrated
colors, distribution of SF regions, morphologies, and local environments. We
found that these KUGs consist of distorted spiral galaxies and compact galaxies
with blue colors. Their star formation occurs in the entire disk, and is not
confined to just the central regions. The colors of the SF regions imply that
active star formation in the spiral galaxies occurred yr ago,
while that of the compact objects occurred yr ago. Though the
photometric characteristics of these KUGs are similar to those of interacting
galaxies or mergers, most of these KUGs do not show direct evidence of merger
processes.Comment: 39 pages LaTeX, using aasms4.sty, 20 figures, ApJS accepted. The
Title of the previous one was truncated by the author's mistake, and is
corrected. Main body of the paper is unchange
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