49 research outputs found
Comparison of Structural Development and Biochemical Accumulation of Waxy and Non-waxy Wheat Caryopses
This study was conducted to compare structural development and biochemical accumulation of waxy and non-waxy wheat (NW) caryopses. The caryopses’ microstructure of the waxy wheat (WW) and NW cultivars at different developmental stages were observed under light, fluorescence, and scanning electron microscope. The results were as follows: Compared with NW,WWhad a shorter maturation duration, which was reflected in several following characteristics. Programmed cell death of the pericarp began earlier, and the chlorophyll-containing layer in the pericarp was smaller. Vacuoles in chalazal cells accumulated more tannins at different developmental stages. Starch granules and protein bodies in the endosperm showed a higher accumulation level in developing caryopses, and aleurone cells were larger in size with larger numbers of aleurone grains. An analysis of the element content indicated that the mineral elements Mg, P, K, and Ca exhibited a higher content, while the heavy elements Cr, Cd, and Pb exhibited a lower content in the aleurone layer
Relativistic mean-field study of neutron-rich nuclei
A relativistic mean-field model is used to study the ground-state properties
of neutron-rich nuclei. Nonlinear isoscalar-isovector terms, unconstrained by
present day phenomenology, are added to the model Lagrangian in order to modify
the poorly known density dependence of the symmetry energy. These new terms
soften the symmetry energy and reshape the theoretical neutron drip line
without compromising the agreement with existing ground-state information. A
strong correlation between the neutron radius of 208Pb and the binding energy
of valence orbitals is found: the smaller the neutron radius of 208Pb, the
weaker the binding energy of the last occupied neutron orbital. Thus, models
with the softest symmetry energy are the first ones to drip neutrons. Further,
in anticipation of the upcoming one-percent measurement of the neutron radius
of 208Pb at the Thomas Jefferson Laboratory, a close relationship between the
neutron radius of 208Pb and neutron radii of elements of relevance to atomic
parity-violating experiments is established.Comment: 14 pages, 5 figure
Fabrication of smooth silicon optical devices using proton beam writing
10.1016/j.nimb.2011.02.015Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms269202448-2451NIMB
Directed transport in deformable ratchets
Transport of overdamped Brownian particles in deformable potentials is investigated in
the presence of asymmetrically unbiased fluctuations. It is found that the deformation of
the potential can strongly affect the directed transport. For small noise strength, the
current is not always monotonic function of deformable parameter. For large noise
strength, there exists a value of deformable parameter at which the current takes its
maximum. Therefore, it is possible to obtain the optimal transport by changing the
deformation of the potential
A silicon-based technology for the fabrication of smooth optical devices
10.1109/PGC.2010.57059402010 Photonics Global Conference, PGC 2010
Use of a line focus of a quadrupole multiplet for irradiating millimeter length lines
10.1016/j.nimb.2011.02.002Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms2698729-732NIMB
Effects of oxide formation around core circumference of silicon-on-oxidized-porous-silicon strip waveguides
10.1364/OL.34.003142Optics Letters34203142-3144OPLE
Novel types of silicon waveguides fabricated using proton beam irradiation
10.1117/12.841536Proceedings of SPIE - The International Society for Optical Engineering7606-PSIS
Fabrication of low-loss silicon-on-oxidized-porous-silicon strip waveguide using focused proton-beam irradiation
We have successfully fabricated low-loss silicon-on-oxidized-porous-silicon (SOPS) strip waveguides with high-index contrast using focused proton-beam irradiation and electrochemical etching. Smooth surface quality with rms roughness of 3.1 nm is achieved for a fluence of 1x1015/cm2 after postoxidation treatment. Optical characterization at a wavelength of 1550 nm shows a loss of 1.1±0.4 dB/cm and 1.2±0.4 dB/cm in TE and TM polarization respectively, which we believe is the lowest reported loss for SOPS waveguides. This opens up new opportunities for all-silicon-based optoelectronics applications