7,328 research outputs found

    Secoviridae: a proposed family of plant viruses within the order Picornavirales that combines the families Sequiviridae and Comoviridae, the unassigned genera Cheravirus and Sadwavirus, and the proposed genus Torradovirus

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    The order Picornavirales includes several plant viruses that are currently classified into the families Comoviridae (genera Comovirus, Fabavirus and Nepovirus) and Sequiviridae (genera Sequivirus and Waikavirus) and into the unassigned genera Cheravirus and Sadwavirus. These viruses share properties in common with other picornavirales (particle structure, positive-strand RNA genome with a polyprotein expression strategy, a common replication block including type III helicase, a 3C-like cysteine proteinase and type I RNA-dependent RNA polymerase). However, they also share unique properties that distinguish them from other picornavirales. They infect plants and use specialized proteins or protein domains to move through their host. In phylogenetic analysis based on their replication proteins, these viruses form a separate distinct lineage within the picornavirales branch. To recognize these common properties at the taxonomic level, we propose to create a new family termed “Secoviridae” to include the genera Comovirus, Fabavirus, Nepovirus, Cheravirus, Sadwavirus, Sequivirus and Waikavirus. Two newly discovered plant viruses share common properties with members of the proposed family Secoviridae but have distinct specific genomic organizations. In phylogenetic reconstructions, they form a separate sub-branch within the Secoviridae lineage. We propose to create a new genus termed Torradovirus (type species, Tomato torrado virus) and to assign this genus to the proposed family Secoviridae

    Pulsed Quantum Frequency Combs from an Actively Mode-locked Intra-cavity Generation Scheme

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    We introduce an intra-cavity actively mode-locked excitation scheme for nonlinear microring resonators that removes the need for external laser excitation in the generation of pulsed two-photon frequency combs. We found a heralded anti-bunching dip of 0.245 and maximum coincidence-to-accidental ratio of 110 for the generated photon pairs

    On-chip Quantum State Generation by Means of Integrated Frequency Combs

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    Summary form only given. This paper investigates different approaches to generate optical quantum states by means of integrated optical frequency combs. These include the generation of multiplexed heralded single-photons, the first realization of cross-polarized photon-pairs on a photonic chip, the first generation of multiple two-photon entangled states, and the first realizations of multi-photon entangled quantum states on a photonic chip

    Generation of Complex Quantum States Via Integrated Frequency Combs

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    The generation of optical quantum states on an integrated platform will enable low cost and accessible advances for quantum technologies such as secure communications and quantum computation. We demonstrate that integrated quantum frequency combs (based on high-Q microring resonators made from a CMOS-compatible, high refractive-index glass platform) can enable, among others, the generation of heralded single photons, cross-polarized photon pairs, as well as bi- and multi-photon entangled qubit states over a broad frequency comb covering the S, C, L telecommunications band, constituting an important cornerstone for future practical implementations of photonic quantum information processing

    Using Lorentz forces to control the distribution of bubbles in a vertical tube filled with liquid metal

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    In this work, a method to increase the residence time of bubbles in tubes or pipes filled with liquid metal is investigated. Imposing a horizontal electric current and a perpendicular horizontal magnetic field generates an upward-directed Lorentz force. This force can counteract gravity and cause floating of bubbles. Even with homogeneous electric fields these float in the mean but fluctuate randomly within the swarm due to mutual interactions. In the present case the cylindrical shape of the container furthermore creates inhomogeneous electric currents and an inhomogeneous force distribution resulting in a macroscopic convection pattern stirring the bubbles and further homogenising the spatial distribution of the bubbles.LIMTECHDFG/HE 7529/1-

    A Passively Mode-locked Nanosecond Laser with an Ultra-narrow Spectral Width

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    Many different mode-locking techniques have been realized in the past [1, 2], but mainly focused on increasing the spectral bandwidth to achieve ultra-short coherent light pulses with well below picosecond duration. In contrast, no mode-locked laser scheme has managed to generate Fourier-limited nanosecond long pulses, which feature narrow spectral bandwidths (~MHz regime) instrumental to applications in spectroscopy, efficient excitation of molecules, sensing, and quantum optics. The related limitations are mainly caused by the adverse operation timescales of saturable absorbers, as well as by the low strength of the nonlinear effects typically reachable through nanosecond pulses with manageable energies
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