3,237 research outputs found

    In situ measurement of the dynamic structure factor in ultracold quantum gases

    Full text link
    We propose an experimental setup to efficiently measure the dynamic structure factor of ultracold quantum gases. Our method uses the interaction of the trapped atomic system with two different cavity modes, which are driven by external laser fields. By measuring the output fields of the cavity the dynamic structure factor of the atomic system can be determined. Contrary to previous approaches the atomic system is not destroyed during the measurement process.Comment: 5 pages, 3 figure

    Die neue Architektur der internationalen Finanzwelt

    Full text link
    Statements von Georg Fahrenschon, Axel A. Weber, Theodor Weime

    Draft Genome Sequences of Campylobacter jejuni Strains That Cause Abortion in Livestock.

    Get PDF
    Campylobacter jejuni is an intestinal bacterium that can cause abortion in livestock. This publication announces the public release of 15 Campylobacter jejuni genome sequences from isolates linked to abortion in livestock. These isolates are part of the 100K Pathogen Genome Project and are from clinical cases at the University of California (UC) Davis

    Spectroscopic Temperature Measurements for a Direct Current Arcjet Diamond Chemical Vapor Deposition Reactor

    Get PDF
    The diamond thin filmcommercial market isprojected to exceed one billion dollars by the year 2000. Potential applications of diamond thin films range from cutting tools to electronics tomedical devices. The explosion ofinterest in this fieldresults from the extreme properties diamond possesses: itis the hardest material known toman and yet, has a coefficient of friction similar to Teflon;its ability to conduct heat is five times that of copper; and diamond is completely inert. However, despite the tremendous economic incentive, there are still several technological barriers preventing diamond filmscale-up to commercial production. Included among these are a fundamental understanding of the gas phase chemistry leading to diamond filmformation and the lack of a reliable insitu, on-line Chemical Vapor Deposition (CVD)monitoring capability. Here we describe the use of optical emission spectroscopy (OES) as a possible direct current CVD plasma jet on-line monitor. Specifically, OES spectra from the C2 radical, an intermediate species in the diamond CVD process, is utilized to obtain plasma gas temperatures insitu. Additionally, the reliability of a plasma gas temperature determined fromOES is examined withLaser-Induced-Fluorescence (LIF)

    Draft Genome Sequence of Multidrug-Resistant Abortive Campylobacter jejuni from Northern California.

    Get PDF
    Campylobacter jejuni is an enteric bacterium that can cause abortion in livestock. This is the release of a multidrug-resistant Campylobacter jejuni genome from an isolate that caused an abortion in a cow in northern California. This isolate is part of the 100K Pathogen Genome Project

    Neural Attentive Session-based Recommendation

    Full text link
    Given e-commerce scenarios that user profiles are invisible, session-based recommendation is proposed to generate recommendation results from short sessions. Previous work only considers the user's sequential behavior in the current session, whereas the user's main purpose in the current session is not emphasized. In this paper, we propose a novel neural networks framework, i.e., Neural Attentive Recommendation Machine (NARM), to tackle this problem. Specifically, we explore a hybrid encoder with an attention mechanism to model the user's sequential behavior and capture the user's main purpose in the current session, which are combined as a unified session representation later. We then compute the recommendation scores for each candidate item with a bi-linear matching scheme based on this unified session representation. We train NARM by jointly learning the item and session representations as well as their matchings. We carried out extensive experiments on two benchmark datasets. Our experimental results show that NARM outperforms state-of-the-art baselines on both datasets. Furthermore, we also find that NARM achieves a significant improvement on long sessions, which demonstrates its advantages in modeling the user's sequential behavior and main purpose simultaneously.Comment: Proceedings of the 2017 ACM on Conference on Information and Knowledge Management. arXiv admin note: text overlap with arXiv:1511.06939, arXiv:1606.08117 by other author

    Heat flux operator, current conservation and the formal Fourier's law

    Full text link
    By revisiting previous definitions of the heat current operator, we show that one can define a heat current operator that satisfies the continuity equation for a general Hamiltonian in one dimension. This expression is useful for studying electronic, phononic and photonic energy flow in linear systems and in hybrid structures. The definition allows us to deduce the necessary conditions that result in current conservation for general-statistics systems. The discrete form of the Fourier's Law of heat conduction naturally emerges in the present definition

    Effective thermodynamics of strongly coupled qubits

    Full text link
    Interactions between a quantum system and its environment at low temperatures can lead to violations of thermal laws for the system. The source of these violations is the entanglement between system and environment, which prevents the system from entering into a thermal state. On the other hand, for two-state systems, we show that one can define an effective temperature, placing the system into a `pseudo-thermal' state where effective thermal laws are upheld. We then numerically explore these assertions for an n-state system inspired by the spin-boson environment.Comment: 9 pages, 3 figure
    corecore