27,892 research outputs found

    Dr. Yang Zhong: an explorer on the road forever

    Get PDF
    On the morning of September 25th 2017, grievous news spread from the remote Ordos region of Inner Mongolia to Fudan University campus in Shanghai. Professor Yang Zhong, a famous botanist and the Dean of Fudan University’s graduate school, passed away in a tragic car accident while on a business trip

    Beam energy dependence of Hanbury-Brown-Twiss radii from a blast-wave model

    Get PDF
    The beam energy dependence of correlation lengths (the Hanbury-Brown-Twiss radii) is calculated by using a blast-wave model and the results are comparable with those from RHIC-STAR beam energy scan data as well as the LHC-ALICE measurements. A set of parameter for the blast-wave model as a function of beam energy under study are obtained by fit to the HBT radii at each energy point. The transverse momentum dependence of HBT radii is presented with the extracted parameters for Au + Au collision at sNN=\sqrt{s_{NN}} = 200 GeV and for Pb+Pb collisions at 2.76 TeV. From our study one can learn that particle emission duration can not be ignored while calculating the HBT radii with the same parameters. And tuning kinetic freeze-out temperature in a range will result in system lifetime changing in the reverse direction as it is found in RHIC-STAR experiment measurements.Comment: 9 pages, 9 figure

    Requirement of Akt to mediate long-term synaptic depression in Drosophila

    Get PDF
    Drosophila larval neuromuscular junction (NMJ) is a well established preparation enabling quantitative analyses of synaptic physiology at identifiable synapses. Here, we report the first characterization of synaptic long-term depression (LTD) at the Drosophila NMJ. LTD can be reliably induced by specific patterns of tetanic stimulation, and the level of LTD depends on both stimulus frequency and Ca2+ concentration. We provide evidence that LTD is likely a result of presynaptic changes. Through screening of targeted mutants with defects in memory or signal transduction pathways, we found that LTD is strongly reduced in the akt mutants. This defect can be rescued by acutely induced expression of the normal akt transgene, suggesting that altered LTD is not attributable to developmental abnormalities and that Akt is critical for the induction of LTD. Our study also indicates that the molecular mechanisms of LTD are distinct from that of short-term synaptic plasticity, because akt mutants showed normal short-term facilitation and posttetanic potentiation, whereas LTD was unaffected in mutants that exhibit defective short-term synaptic plasticity, such as dunce and rutabaga. The characterization of LTD allows genetic analysis of the molecular mechanisms of long-term synaptic plasticity in Drosophila and provides an additional assay for studying functions of genes pertaining to synaptic and behavioral plasticity

    Deregulation of power systems in Asia: Special consideration in developing countries

    Get PDF
    Power industry is undergoing restructuring throughout the world. The traditional vertically monopolistic structure has been deregulated and replaced by gencos, transcos and discos with competition introduced to gencos and discos in order to reach higher efficiency in electricity production and utilization. A lot of power markets have been established for the purpose. However for different countries, the principal objectives and considerations of power system deregulation are different. In this paper special considerations on power system deregulation of developing countries in Asia are discussed. Two regional power markets in China are used as examples. It is shown that for developing countries, the main objectives of power system deregulation are to attract various investments to power industry in order to meet the fast growth of electric demand caused by blooming economy and in the meantime to reduce government commitment and functions in power industry. Only this way, the power industry, as a significant infrastructure, can realize sustainable development at high efficiency. It is also shown that in the market environment, how to realize optimal system planning and reliable operation at acceptable electricity prices with qualifies service and how to transit to the market environment smoothly at lowest costs and lowest risks should be considered thoroughly. © 2005 IEEE.published_or_final_versio
    corecore