Dr Benabid’s team has not only made an important step in applied physics, but has contributed to the theory of photonics too. The effectiveness of photonic crystal fibre has lain so far in its exploitation of what is called photonic band gap, which stops photons of light from “existing” in the fibre cladding and enabled them to be trapped in the inside core of the fibre.
Instead, the team makes use of the fact that light can exist in different ‘modes’ without strongly interacting. This creates a situation whereby light can be trapped inside the fibre core without the need of photonic bandgap. Physicists call these modes bound states within a continuum.
The existence of these bound states between photons was predicted at the beginning of quantum mechanics in the 1930s, but this is the first time it has been noted in reality, and marks a theoretical breakthrough.
...."One immediate purpose of these experiments is to obtain large crystals of sufficient size and quality to compare with corresponding crystals grown in Earth-based laboratories. An ongoing objective is to determine the best mixtures to use in flash-frozen batch and liquid-liquid diffusion techniques for growing protein and virus crystals on long-duration space missions."
so corresponding crystals were grown in labs as well, but they are smaller?
protein crystal growth (PCG) outer space vs those grown in labs/ wonder which labs?
Synthesis of High-Yield Gold Nanoplates: Fast Growth Assistant with Binary Surfactants
For anisotropic Au and Ag nanostructures, various shapes, such as nanorods, nanowires, nanoplates, nanorings, polyhedron, nanoprisms, and nanocubes [10–25], can be synthesized by seed-mediated synthesis [15, 19], template-directed synthesis , polymer-assisted synthesis , microwave heating , and chemical approach (electrochemistry, photochemistry, and sonochemistry) [24, 25].
Among these anisotropic nanoparticals, the monodispersity of two-dimensional nanoplates with flat surfaces and regular shapes has attracted great attention due to their promising applications in distinctive optical properties associated with the collective oscillations of conduction electrons [21, 26]. In the case of Au platelets, the crystal was usually synthesized via the modified polyol procedure (ethylene glycol in most cases) with the presence of capping agents. Among the capping agents, Poly(vinylpyrrolidone) (PVP) was extensively used in preparing many types of colloidal nanocrystals, because it not only has a reducing effect on metal ions and but also can prevent the product from agglomeration . Another cationic surfactant, cetyltrimethylammonium bromide (CTAB), was also used to control the morphology of nanoparticles (Au nanorods in most cases) [28–30]. Recently, one group reported a wet-chemical process for the seed-mediated growth of Au nanoplates on an indium tin oxide surface with binary surfactants PVP and CTAB . At present, the clear action of surfactants during the fabrication of nanoparticles is still a challenge.
Zhi-Yuan Jiang, Qin Kuang, Zhao-Xiong Xie, Lan-Sun Zheng Syntheses and Properties of Micro/Nanostructured Crystallites with High-Energy Surfaces [Feature Article] adfm201001243.jpg
Micro/nanostructured crystallites with high-energy surfaces have attracted increasing attention owing to their fascinating surface-dependent properties and promising applications. This feature article provides a brief account of these efforts, especially on several typical crystal structures, including the wurtzite structure (ZnO), rocksalt structure (MgO), anatase structure (TiO2), rutile structure (SnO2), and face-centered cubic (Au) structure.
tash: Hi skizit, I have watched all your videos on youtube and cant thank you enough for all you have educated me on. I cry for you alot and a bit for me. I was wanting to send you photos of what is raining down everyday here in Australia in hope you can tell me
Dec 11, 2019 23:28:22 GMT -5
tash: not sure where to send them as hush mail and rocket mail bounced back
Dec 11, 2019 23:30:03 GMT -5