2,917 research outputs found

    Measurement of the entanglement spectrum of a symmetry-protected topological state using the IBM quantum computer

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    Entanglement properties are routinely used to characterize phases of quantum matter in theoretical computations. For example the spectrum of the reduced density matrix, or so-called "entanglement spectrum", has become a widely used diagnostic for universal topological properties of quantum phases. However, while being convenient to calculate theoretically, it is notoriously hard to measure in experiments. Here we use the IBM quantum computer to make the first ever measurement of the entanglement spectrum of a symmetry-protected topological state. We are able to distinguish its entanglement spectrum from those we measure for trivial and long-range ordered states.Comment: 8 pages, 4 figure

    Order-disorder transition and alignment dynamics of a block copolymer under high magnetic fields by in situ x-ray scattering

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    We present results of temperature resolved scattering studies of a liquid crystalline block copolymer undergoing an order-disorder transition (ODT) in the presence of magnetic fields and time-resolved measurements during isothermal field annealing at sub-ODT temperatures. In each case, field interactions produced strongly textured mesophases with the cylindrical microdomains aligned parallel to the field. We find there is no measurable field-induced shift in the ODT temperature (TODTT_{ODT}) which suggests that selective melting does not play a role in mesophase alignment during isothermal experiments. Our data indicate instead that sub-ODT alignment occurs by slow, large scale grain rotation whereas alignment during cooling from the disordered melt is rapid and driven by the nucleation of weakly ordered but preferentially aligned material. We identify an optimum sub-cooling that maximizes alignment during isothermal field annealing. This is corroborated by a simple model incorporating the competing effects of an exponentially decreasing mobility and divergent, increasing magnetic anisotropy on cooling below TODTT_{ODT}. The absence of measurable field-effects on TODTT_{ODT} is consistent with rough estimates derived from the relative magnitudes of the free energy due to field interaction and the enthalpy of the isotropic-LC transition.Comment: 5 figures; To appear in Physical Review Letter

    Targeted Therapy in Hepatocellular Carcinoma

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    Hepatocellular carcinoma (HCC) is one of the commonest cancers worldwide, as well as a common cause of cancer-related death. HCC frequently occurs in the setting of a diseased cirrhotic liver and many patients present at an advanced stage of disease. Together with a poor functional status, this often precludes the use of systemic therapy, especially conventional cytotoxic drugs. Moreover, HCC is known to be a relatively chemo-refractory tumor. There have been many targeted drugs that have shown potential in the treatment of HCC. Many clinical trials have been carried out with many more in progress. They include trials evaluating a single targeted therapy alone, two or more targeted therapy in tandem or a combination of targeted therapy and conventional chemotherapy. In this article, we seek to review some of the more important trials examining the use of targeted therapy in HCC and to look into what the future holds in terms of targeted treatment of HCC

    CHEMISTRY OF VIRAL INFECTED CELLS *

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73699/1/j.1749-6632.1960.tb20121.x.pd

    NASA Workshop on future directions in surface modeling and grid generation

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    Given here is a summary of the paper sessions and panel discussions of the NASA Workshop on Future Directions in Surface Modeling and Grid Generation held a NASA Ames Research Center, Moffett Field, California, December 5-7, 1989. The purpose was to assess U.S. capabilities in surface modeling and grid generation and take steps to improve the focus and pace of these disciplines within NASA. The organization of the workshop centered around overviews from NASA centers and expert presentations from U.S. corporations and universities. Small discussion groups were held and summarized by group leaders. Brief overviews and a panel discussion by representatives from the DoD were held, and a NASA-only session concluded the meeting. In the NASA Program Planning Session summary there are five recommended steps for NASA to take to improve the development and application of surface modeling and grid generation

    An educational durian? Issues in teacher education in international collaboration

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    This paper looks at an international collaborative project in teacher education between Malaysian Institutes of teacher training and an Australian university from the perspectives of four of the participants. Two of the stories are from participants who are co-ordinating aspects of the collaboration, and two stories come from participants who were involved closely in the curriculum and teaching aspects of the program. These personal stories reveal that international collaborative projects are indeed like the durian: there are both good and bad aspects. Our differing roles in the program allow us to provide rich insights into such an international collaboration that we believe will be of benefit to others attempting similar projects.<br /

    Lico: A Lightweight Access Control Model for Inter-Networking Linkages

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    © 2013 IEEE. Processes in operating systems are assigned different privileges to access different resources. A process may invoke other processes whose privileges are different; thus, its privileges are expanded (or escalated) due to such improper 'inheritance.' Inter-networking can also occur between processes, either transitively or iteratively. This complicates the monitoring of inappropriate privilege assignment/escalation, which can result in information leakage. Such information leakage occurs due to privilege transitivity and inheritance and can be defined as a general access control problem for inter-networking linkages. This is also a topic that is generally less studied in existing access control models. Specifically, in this paper, we propose a lightweight directed graph-based model, LiCo, which is designed to facilitate the authorization of privileges among inter-networking processes. To the best of our knowledge, this is the first general access control model for inter-invoking processes and general inter-networking linkages

    Thermophysical and elastic properties of Cu50Zr50 and (Cu50Zr50)95Al5 bulk-metallic-glass-forming alloys

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    By employing a containerless high-temperature high-vacuum electrostatic levitation technique, the thermophysical properties, including the ratio between the specific heat capacity and the hemispherical total emissivity, the specific volume, and the viscosity, of Cu50Zr50 and (Cu50Zr50)95Al5 bulk-metallic-glass (BMG)-forming liquids have been measured. Compared with Cu50Zr50, the improved glass-forming ability of (Cu50Zr50)95Al5 can be attributed to its dense liquid structure and its high value of viscosity. Additionally, the relationship between the viscosity of various BMG forming liquids at the melting temperature and the elastic properties of the corresponding glasses at room temperature will be compared
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