Results 71 to 80 of about 1,347 (193)
Magnetic Resonance in Medicine, EarlyView.ABSTRACT Purpose The design of radiofrequency (RF) coils tailored for the target anatomy is necessary to overcome the transmit field homogeneity and penetration issues at Ultra‐High‐Field (UHF). For the spinal cord, the optimal design has not yet been determined. This work intends to demonstrate the added value of a pair of passive dipoles placed under
Hugo Amat +10 more
wiley +1 more source
Finite-Difference Time-Domain Simulation Of Low-F# Fresnel Zone Plates Coupled To Ir Antennas [PDF]
, 2004 Fresnel Zone Plate Lenses (FZPLs) have been successfully coupled to infrared (IR) antennas producing a responsivity enhancement of about two orders of magnitude.
Boreman, Glenn +7 more
core +2 more sources
Nature Communications, 2023 Planar diffractive lenses (PDLs) with optimized but disordered structures can focus light beyond the diffraction limit. However, these disordered structures have inevitably destroyed wide-field imaging capability, limiting their applications in ...
Jun He +5 more
doaj +1 more source
Near Surface Geophysics, EarlyView.Abstract The United Kingdom's shallow aquifers offer significant but underdeveloped geothermal energy resource. Seismic methods can help address this by improving the understanding of aquifer heterogeneity and potentially allowing long‐term monitoring of thermal plumes.
Adam D. Booth +10 more
wiley +1 more source
Fabrication of Fresnel zone plates for hard X-rays [PDF]
A method to fabricate gold structures with high aspect ratio is presented. Fresnel zone plates with an outermost zone width of 100nm and structures of 1μm height are fabricated.
Grolimund, D. +5 more
core +1 more source
MRI Compatible Fresnel Zone Plates made of Polylactic Acid [PDF]
, 2018 Zone Plates (ZPs) are used in many areas of physics where planar fabrication is advantageous in comparison with conventional curved lenses. There are several types of ZPs, such as the well-known Fresnel ZPs or the more recent Fractal ZPs and Fibonacci ...
Pilar Candelas +4 more
core +1 more source
Small, EarlyView.ABSTRACT Scanning transmission x‐ray microscopy (STXM) is a nanoscale imaging technique that can utilize several powerful contrast mechanisms for the quantitative mapping of chemical and physical materials properties. Spatial resolutions down to 7 nm at the soft x‐ray energy range have been demonstrated.
Simone Finizio +6 more
wiley +1 more source
Material optimization for hard x-ray Fresnel zone plates [PDF]
, 1993 Fresnel zone plates have recently been used as the focusing optic for hard x-ray (5--11 keV) microscopy techniques. Fresnel zone plates used in the hard x-ray regime focus by constructive interference effects based on the phase modulation of the incident
Chrzas, J. +4 more
core
Influence of random zone positioning errors on the resolving power of Fresnel zone plates [PDF]
, 2014 Fresnel zone plates produced by electron beam lithography and planar etching techniques provide a resolving power of about 10 nm. An alternative zone plate fabrication approach is based on alternately coating a micro wire with two different materials.
Rehbein, S. +3 more
core +1 more source
The Generation of Equal-Intensity and Multi-Focus Optical Vortices by a Composite Spiral Zone Plate
PhotonicsWe propose a new vortex lens for producing multiple focused coaxial vortices with approximately equal intensities along the optical axis, termed equal-intensity multi-focus composite spiral zone plates (EMCSZPs).
Huaping Zang +9 more
doaj +1 more source