21 research outputs found
Scalable microstructured semiconductor THz pulse sources
In recent years several microstructured lithium niobate THz pulse source were suggested for high-energy applications. Two types of those, the reflective and the transmissive
nonlinear slab are adopted here for semiconductors. These new sources are scalable both in THz energy and size. Furthermore, they can outperform the already demonstrated contact grating source in diffraction and THz generation efficiency. Compared to the lithium niobate sources,
they are more feasible, thanks to the easier manufacturing and the longer pump wavelength.
They can produce intense, nearly single-cycle THz pulses at higher frequencies. With 20 mJ pumping at 1.8 ÎĽm wavelength, 45 ÎĽJ THz energy, and 17 MV/cm focused peak electric field can be expected at 3 THz phase matching frequency from the transmissive nonlinear echelon slab setup consisting of a 4 mm thick structured plan-parallel gallium phosphide crystal
Genome of the pitcher plant <i>Cephalotus </i>reveals genetic changes associated with carnivory
Carnivorous plants exploit animals as a nutritional source and have inspired long-standing questions about the origin and evolution of carnivory-related traits. To investigate the molecular bases of carnivory, we sequenced the genome of the heterophyllous pitcher plant Cephalotus follicularis, in which we succeeded in regulating the developmental switch between carnivorous and non-carnivorous leaves. Transcriptome comparison of the two leaf types and gene repertoire analysis identified genetic changes associated with prey attraction, capture, digestion and nutrient absorption. Analysis of digestive fluid proteins from C. follicularis and three other carnivorous plants with independent carnivorous origins revealed repeated co-options of stress-responsive protein lineages coupled with convergent amino acid substitutions to acquire digestive physiology. These results imply constraints on the available routes to evolve plant carnivory
Yoga in the dimension of physical activity
A fizikai aktivitás és az egészség közötti kapcsolat vitathatatlan. A társadalom nagy része nem végez megfelelő mennyiségű testmozgást, ennek következtében gyakori a megbetegedés, és a korai halálozás. Az utóbbi években a nyugati civilizációkban, ahogy hazánkban is egyre nagyobb szerepet kap a jóga az egészségmegőrzésben, szabadidős tevékenységként, illetve a test és a lélek összhangja kapcsán.
A jĂłga egy olyan mozgásforma amely kortĂłl, nemtĹ‘l Ă©s sĂşlytĂłl fĂĽggetlenĂĽl is vĂ©gezhetĹ‘. IgĂ©nytĹ‘l fĂĽggĹ‘en szinte bármekkora intenzitási szint elĂ©rhetĹ‘ jĂłgázás közben, emellett nagyon sokfĂ©le pozitĂv egĂ©szsĂ©gĂĽgyi hatás társulhat hozzá. Fontosnak tartottam, hogy a jĂłgát a fizikai aktivitás dimenziĂłjában megvizsgáljam Ă©s összegyűjtsem a holisztikus egĂ©szsĂ©gre gyakorolt hatását. A kutatĂłmunka elvĂ©gzĂ©se után választ kaptam a felmerĂĽlt kĂ©rdĂ©seimre, Ă©s messze menĹ‘ következtetĂ©seket tudtam levonni a tĂ©ma kapcsán.BSc/BASportszervezĹ‘K
Demonstration of a tilted-pulse-front pumped planparallel slab terahertz source
THz pulse generation in a nonlinear optical slab with an entrance surface having an echelon structure is demonstrated. The setup uses a transmission grating and a planeparallel lithium-niobate crystal slab, and ensures a good-quality, symmetric THz beam and enables scalability to high pulse energies