Visual Analytics este știința rațiunii analitice, facilitată de interfețele vizuale interactive;este de a investiga și de a promova colaborarea în domeniul extragerii de cunoștințe și a stocării datelor, pentru a oferi o conștiință situațională în timp util pentru luarea unor decizii eficiente
Obiectivele SET-233 continuă cu îmbunătățiri în detectarea acustică tranzitorie a evenimentelor, localizarea, clasificarea, atenuarea efectelor de propagare și fuziunea senzorilor multimodali
Aprecierea Apărării a fost cu adevărat impresionată de cele două unități pe care le-am văzut la SHOT și ne-ar plăcea să obținem o unitate pentru următoarea dinamică CQB / CQC forțată-for-force (aproape Quarters Battle / Close Quarters Combat) curs de luptă ușoară
au construit primul laser cu cascadă cuantică pe siliciu. Progresul poate avea aplicații care se întind de la spectroscopia de legături chimice și de detectarea gazelor, până la astronomia și comunicațiile spațiului liber.construirea acestor dispozitive fotonice cu siliciu pentru lungimi de undă mai lungi în mijlocul infraroșiei, pentru o gamă de aplicații de detectare și detectare, cum ar fi spectroscopia de legături chimice, senzația de gaz, astronomia, senzorizarea oceanografică, imagistica termică, spațiul liber de comunicații.
| Posted: Apr 20, 2016 | |
Team builds first quantum cascade laser on silicon(Nanowerk News) A team of researchers from across the country, led by Alexander Spott, University of California, Santa Barbara, USA, have built the first quantum cascade laser on silicon. The advance may have applications that span from chemical bond spectroscopy and gas sensing, to astronomy and free-space communications. |
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| 3-D artistic depiction of multiple Quantum Cascade Lasers integrated above silicon waveguides. (Image: Alexander Spott) | |
| Integrating lasers directly on silicon chips is challenging, but it is much more efficient and compact than coupling external laser light to the chips. The indirect bandgap of silicon makes it difficult to build a laser out of silicon, but diode lasers can be built with III-V materials such as InP or GaAs. By directly bonding an III-V layer on top of the silicon wafer and then using the III-V layers to generate gain for the laser, this same group has integrated a multiple quantum well laser on silicon that operates at 2 µm. Limitations in diode lasers prevent going to longer wavelengths where there are many more applications, so the group turned their attention to using quantum cascade lasers instead. | |
| Building a quantum cascade laser on silicon was a challenging task made more difficult by the fact that silicon dioxide becomes heavily absorptive at longer wavelengths in the mid-infrared. | |
| „This meant that not only did we have to build a different type of laser on silicon, we had to build a different silicon waveguide too,” Spott explained. „We built a type of waveguide called a SONOI waveguide [silicon-on-nitride-on-insulator], which uses a layer of silicon nitride [SiN] underneath the silicon waveguide, rather than just SiO2.” | |
| The breakthrough could lead to several applications, Spott explained. Traditionally, silicon photonic devices operate at near-infrared wavelengths, with applications in data transmission and telecommunications. However, there is emerging research interest in building these silicon photonic devices for longer mid-infrared wavelengths, for a range of sensing and detection applications, such as chemical bond spectroscopy, gas sensing, astronomy, oceanographic sensing, thermal imaging, explosive detection, and free-space communications. | |
| The next step for the team is to improve the heat dissipation to improve the performance of these QCLs and to allow them to make continuous-wave QCLs on silicon. „We generally hope to improve the design to get higher powers and efficiency,” Spott said. „This brings us closer to building fully integrated mid-infrared devices on a silicon chip, such as spectrometers or gas sensors. Silicon is inexpensive, the fabrication can be scaled up to significantly reduce the cost of individual chips, and many small devices can be built on the same silicon chip for example multiple different types of sensors operating at different mid-infrared wavelengths.” | |
| About the Presentation | |
| The presentation „Quantum Cascade Laser on Silicon at 4.8 µm,” by Alexander Spott, Jon Peters, Michael Davenport, Eric Stanton, Charles Merritt, William Bewley, Igor Vurgaftman, Jerry Meyer, Jeremy Kirch, Luke Mawst, Dan Botez, John Bowers, will take place from 14:00 – 16:00, Thursday, 09 June 2016, San Jose Convention Center, San Jose, California, USA. |
| Source: The Optical Society |
Sistem bazat pe laser pentru a ajuta la detectarea armelor chimice, a explozivilor, a narcoticelor și multe altele
Brățările din silicon simulează modul în care organismul absoarbe compuși toxici
Sistem de laser pentru detectia armelor chimice, explozibile , narcotice ,etc
sistem de dectie al armelor chimice , explozive, narcotice ,etc . Proiect de dezvoltare-cercetare al fortelor aeriene
fizicienii sunt interesați de o generație de materiale artificiale, ale căror proprietăți pot fi controlate. Cercetătorii de la Universitatea din Geneva (UNIGE), Elveția, în colaborare cu echipele franceze și engleze, au reușit să manipuleze proprietățile a doi oxizi care alcătuiesc materialul artificial, mai exact au reușit să modifice proprietățile magnetice care pot fi fie feromagnetice sau antiferomagnetic; adică, cu sau fără moment magnetic net.
| Posted: Apr 15, 2016 | |
Generation of tailored magnetic materials(Nanowerk News) Every day, new technologies require more precision in the intrinsic properties of the materials used. To meet increasingly specific requirements, physicists are interested in a generation of artificial materials, the properties of which can be controlled. Researchers at the University of Geneva (UNIGE), Switzerland, in collaboration with French and English teams, have succeed in manipulating the properties of two oxides which make up the artificial material, more exactly they managed to modify the magnetic properties which can be either ferromagnetic or antiferromagnetic; that is, with or without net magnetic moment. |
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| The scientists have demonstrated, in their study published in Nature Communications („Interlayer coupling through a dimensionality-induced magnetic state”), that they are able now to control the magnetism in this type of materials and that they could, in the near future, offer tailored materials for the devices of tomorrow. | |
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| Artist view of the manipulation of the magnetic properties achieved in the oxide materials LaNiO3and LaMnO3 when few atomic layers of each material are grown one on top of the other successively. In this case, LaNiO3, which initially was conducting and non-magnetic, is found to become insulating and magnetic when in contact with LaMnO3. (Image: Marta Gibert Gutierrez – UNIGE) | |
| When two materials are in contact, they interact in different ways and, sometimes, exchange electrons. But what happens when one stacks up ultrathin layers, of the order of one nanometer? «We have combined two materials, LaNiO3, a metallic paramagnet (without magnetic order), and LaMnO3, an insulating antiferromagnet, by alternating a layer of the first, then of the second, etc. We then observed what the influence of interactions at the interfaces was and we noticed a profound change in the intrinsic properties of the two materials», said a statement from Jean-Marc Triscone, professor at the Department of quantum matter physics in the Faculty of Science of UNIGE. | |
| LaNiO3 and LaMnO3 have the same cubic crystalline structure, and thus the researchers can stack the elemental unit cells of these compounds, that is the small „cubes” made of just a few atoms, by using state-of-the-art technology. They then manage to create an artificial structure with a perfect alignment of the unit cells. To do this, the physicists deposit one unit cell after the other on a substrate; that is a small heated crystal tile. The layers are very thin and their thickness of about a nanometer is controlled precisely at the unit cell. | |
| Goldsmith precision | |
| «In order to realise a perfect structure on the crystal tile, we had to find the exact temperature and pressure conditions required to grow the materials one on top of the other. Then we investigated the properties of the interfaces depending on the number of layers stacked», explain Marta Gibert, researcher in physics at UNIGE and first author of the study. «Measurements of the physical properties then revealed that the properties of LaNiO3 are very different when in contact with LaMnO3. From being a metal without magnetic order, it becomes not only magnetic but also insulating. Moreover, the overall properties of the artificial material depend on the individual thickness of the layer of each material and they can also change as a function of the chosen thickness», added the physicist. | |
| Thanks to this discovery, the researchers are therefore able to control the magnetic state of these materials – a track to build artificial tailored materials according to specific needs in the future. Such control of the magnetic interactions could especially be used to develop future magnetic memories, allowing the high dissipation energy of current processors to be reduced. | |
| This research is not limited to magnetic materials, but it is also of interest for materials that are simultaneously magnetic and ferroelectric, another way to new memories or even to superconducting materials working at higher temperatures – a dream which may be not so distant. |
| Source: Université de Genève |
Cureaua TNVC / Unity Tactical CLUTCH este concepută special pentru transportul ascuns / ascuns pentru operatorii implicați în misiuni de operațiuni ascunse, dar se poate dubla ca o centură de combatere rapidă / reacție de urgență / tactică / luptă pentru operațiuni shooter activ / contraterorism
au dezvoltat un senzor pe bază de grafen și un comutator care poate detecta poluarea dăunătoare a aerului în casă cu o consumare de energie foarte scăzută
