81 research outputs found

    N_pN_n dependence of empirical formula for the lowest excitation energy of the 2^+ states in even-even nuclei

    Full text link
    We examine the effects of the additional term of the type eλNpNn\sim e^{- \lambda' N_pN_n} on the recently proposed empirical formula for the lowest excitation energy of the 2+2^+ states in even-even nuclei. This study is motivated by the fact that this term carries the favorable dependence of the valence nucleon numbers dictated by the NpNnN_pN_n scheme. We show explicitly that there is not any improvement in reproducing Ex(21+)E_x(2_1^+) by including the extra NpNnN_pN_n term. However, our study also reveals that the excitation energies Ex(21+)E_x(2_1^+), when calculated by the NpNnN_pN_n term alone (with the mass number AA dependent term), are quite comparable to those calculated by the original empirical formula.Comment: 14 pages, 5 figure

    Intense pulsed helium droplet beams

    Full text link
    Pulsed (30 - 100 microseconds) nozzle beams have been used to generate helium droplets ( = 10^4-10^5). The dependence of the beam intensity and the mean droplet size on the source stagnation pressure and temperature are studied via mass spectroscopy and laser induced fluorescence of embedded phthalocyanine molecules. In comparison to a cw beam the pulsed source for the same pressure and temperature has a factor of 100 higher flux and the droplet sizes are an order of a magnitude larger.Comment: Accepted by Review of Scientific Instrument

    Findings of the WMT'22 Shared Task on Large-Scale Machine Translation Evaluation for African Languages

    Get PDF
    We present the results of the WMT'22 Shared Task on Large-Scale Machine Translation Evaluation for African Languages. The shared task included both a data and a systems track, along with additional innovations, such as a focus on African languages and extensive human evaluation of submitted systems. We received 14 system submissions from 8 teams, as well as 6 data track contributions. We report a large progress in the quality of translation for African languages since the last iteration of this shared task: there is an increase of about 7.5 BLEU points across 72 language pairs, and the average BLEU scores went from 15.09 to 22.60

    Therapeutic targets and microenvironment in sequential biopsies of classical Hodgkin lymphoma at diagnosis and relapse

    Get PDF
    Classical Hodgkin lymphoma is dominated by the non-neoplastic microenvironment, while the neoplastic Hodgkin-Reed-Sternberg cells compose only a minority of cells in the lymphoma tissue. Both the Hodgkin-Reed-Sternberg cells due to their expression of CD30 and PD-L1 and the microenvironment with abundant T cells and expression of PD1 are specifically targeted by new treatment concepts. We aimed to understand the dynamics of therapeutic targets in patients treated with conventional chemotherapy. We analyzed sequential biopsy specimens obtained at diagnosis and at relapse from the same patient for morphology, immunophenotype, and microenvironmental components. The morphological subtype changed between primary and relapse biopsy in 20% of cases. The immunophenotype was stable with respect to CD30, CD3, and LMP1 but variable with respect to CD15 and CD20 expression. Gene expression revealed 8 upregulated and 20 downregulated genes at relapse (p <= 0.05) with a consistent logarithmic fold change direction in at least 75% of all cases. For PD1, we found discrepant results between gene expression analysis (decrease at relapse) and number of PD1-positive cells assessed by immunohistochemistry (unchanged at relapse). PD-L1 in the neoplastic cells appeared unchanged between primary diagnosis and relapse. The expression of the therapeutic targets CD30, PD1, and PD-L1 can reliably be assessed in tumor specimen at first diagnosis and is unchanged under conventional chemotherapy

    Allogeneic hematopoietic stem cell transplantation in China: where we are and where to go

    Get PDF
    Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective and sometimes the only curative therapy for patients with certain hematological diseases. Allo-HSCT has been practiced in China for approximately 30 years, and great improvements have been made within the past decade, particularly in fields such as the haploidentical HSCT system, strategies to overcome relapse and GVHD, and modified HSCT for elderly patients. This review will describe the current situation and provide a prospective of these unique aspects of Allo-HSCT in China

    Core Level Photelectron and X-Ray Absorption Spectroscopy of Free Argon Clusters: Size-Dependent Energy Shifts and Determination of Surface Atom Coordination

    No full text
    Core level photoelectron and x-ray absorption spectra for free argon clusters from 〈N〉≈5 to 〈N〉≈4000 are presented. Spectral features originating from surface and bulk sites of the clusters are identified. These are seen to shift with cluster size. From the development of the spectra from the isolated atom to the largest clusters, information about both the size-dependent cluster-specific electronic structure and that of the “infinite” solid is obtained. Using a simple model for the core level binding energy shifts, effective surface coordination numbers are derived. These range from 5.3 for 〈N〉≈10 to 8.5 for the solid

    RF Loads for Energy Recovery

    No full text
    Different conceptional designs for RF high power loads are presented. One concept implies the use of solid state rectifier modules for direct RF to DC conversion with efficiencies beyond 80%. In addition, robust metallic low-Q resonant structures, capable of operating at high temperatures (>150 ◦C) are discussed. Another design deals with a very high temperature (up to 800 ◦C) air cooled load using a ceramic foam block inside a metal enclosure. This porous ceramic block is the microwave absorber and is not brazed to the metallic enclosure

    Measurements of electron cloud density in the CERN Super Proton Synchrotron with the microwave transmission method

    No full text
    The electron cloud effect can pose severe performance limitations in high-energy particle accelerators as the CERN Super Proton Synchrotron (SPS). Mitigation techniques such as vacuum chamber thin film coatings with low secondary electron yields (SEY < 1.3) aim to reduce or even suppress this effect. The microwave transmission method, developed and first applied in 2003 at the SPS, measures the integrated electron cloud density over a long section of an accelerator. This paper summarizes the theory and measurement principle and describes the new SPS microwave transmission setup used to study the electron cloud mitigation of amorphous carbon coated SPS dipole vacuum chambers. Comparative results of carbon coated and bare stainless steel dipole vacuum chambers are given for the beam with nominal LHC 25 ns bunch-to-bunch spacing in the SPS and the electron cloud density is derived
    corecore