31,612 research outputs found

    Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV

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    The prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region

    C*-algebras have a quantitative version of Pełczyński's property (V)

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    summary:A Banach space XX has Pełczyński's property (V) if for every Banach space YY every unconditionally converging operator T ⁣:XYT\colon X\to Y is weakly compact. H. Pfitzner proved that CC^*-algebras have Pełczyński's property (V). In the preprint (Krulišová, (2015)) the author explores possible quantifications of the property (V) and shows that C(K)C(K) spaces for a compact Hausdorff space KK enjoy a quantitative version of the property (V). In this paper we generalize this result by quantifying Pfitzner's theorem. Moreover, we prove that in dual Banach spaces a quantitative version of the property (V) implies a quantitative version of the Grothendieck property

    Illuminaçao Apologetica do retrato de Morteçor en que aparecem com mais vivas côres os erros do author do novo Methodo, e seu Apologista ...

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    Fecha sacada de la pág.2 y 159Sign.: A-V\p4\sError tipográfico de signatura : a B\b2\s llama B\b3\

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    A ± 12-A High-Side Current Sensor With 25 V Input CM Range and 0.35% Gain Error From −40 °C to 85 °C

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    This letter presents the most accurate shunt-based high-side current sensor ever reported. It achieves a 25 V input common-mode range from a single 1.8-V supply by using a beyond-the-rails ADC. A hybrid analog/digital temperature compensation scheme is proposed to simplify the circuit implementation while maintaining the state-of-the-art accuracy. Over a ±12-A current range, the sensor exhibits 0.35% gain error from -40 °C to 85 °C with 3× better power efficiency.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic

    Sexual signaling pattern correlates with habitat pattern in visually ornamented fishes

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    Article Open Access Published: 22 May 2020 Sexual signaling pattern correlates with habitat pattern in visually ornamented fishes Samuel V. Hulse, Julien P. Renoult & Tamra C. Mendelson Nature Communications volume 11, Article number: 2561 (2020) Cite this article 1064 Accesses 73 Altmetric Metricsdetails Abstract Sexual signal design is an evolutionary puzzle that has been partially solved by the hypothesis of sensory drive. Framed in signal detection theory, sensory drive posits that the attractiveness of a signal depends on its detectability, measured as contrast with the background. Yet, cognitive scientists have shown that humans prefer images that match the spatial statistics of natural scenes. The explanation is framed in information theory, whereby attractiveness is determined by the efficiency of information processing. Here, we apply this framework to animals, using Fourier analysis to compare the spatial statistics of body patterning in ten species of darters (Etheostoma spp.) with those of their respective habitats. We find a significant correlation between the spatial statistics of darter patterns and those of their habitats for males, but not for females. Our results support a sensory drive hypothesis that recognizes efficient information processing as a driving force in signal evolution.We would like to thank Dr. Thomas Cronin for help with camera calibrations, Matthew Dugas, Natalie Roberts, and Rickesh Patel for assistance with field collections, and the Hancock Biological Station for providing a home base for field work and photography. This work was supported by National Science Foundation grant IOS-1708543 and by the CNRS (PICS project n°08302).https://www.nature.com/articles/s41467-020-16389-

    A 16 MHz CMOS RC Frequency Reference With ±90 ppm Inaccuracy From -45 °C to 85 °C

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    This article presents a 16-MHz RC frequency reference implemented in a standard 180-nm CMOS process. It consists of a frequency-locked loop (FLL) in which the output frequency of a digitally controlled oscillator (DCO) is locked to the frequency-phase characteristic of a Wien bridge RC filter. Since it is made from on-chip resistors and capacitors, the filter's characteristic is temperature dependent. To compensate for this, the control signal of the DCO is derived by digitizing the filter's output phase and combining it with the digital output of a Wheatstone bridge temperature sensor. After a two-point trim, this digital temperature compensation scheme achieves an inaccuracy of ±90 ppm from -45 °C to 85 °C. The frequency reference draws 220 μA\mu \text{A} from a 1.8-V supply, with a supply sensitivity of 0.12%/V and a 320-ppb Allan Deviation floor for a 10-s stride.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic

    A CMOS Dual- RC Frequency Reference With ±200-ppm Inaccuracy From -45 °C to 85 °C

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    This paper presents a 7-MHz CMOS RC frequency reference. It consists of a frequency-locked loop in which the output frequency of a digitally controlled oscillator (DCO) is locked to the combined phase shifts of two independent RC (Wien bridge) filters, each employing resistors with complementary temperature coefficients. The filters are driven by the DCO's output frequency and the resulting phase shifts are digitized by high-resolution phase-to-digital converters. Their outputs are then combined in the digital domain to realize a temperature-independent frequency error signal. This digitally assisted temperature compensation scheme achieves an inaccuracy of ±200 ppm from -45 °C to 85 °C after a two-point trim. The frequency reference draws 430 μA from a 1.8-V supply, while achieving a supply sensitivity of 0.18%/V and a 330-ppb Allan deviation floor in 3 s of measurement time.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronics(OLD)Applied Quantum Architecture

    Dynamics of finite-sized light spheres in turbulence

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    We report experimental results on the Lagrangian dynamics of finite-size light particles in turbulence. Using an orthogonal camera setup and 3D particle tracking, we study the velocity and acceleration statistics of rigid light spheres in a water tunnel with nearly homogeneous and isotropic turbulence. The Reynolds number (ReY) is varied from 180 to 300, and the study covers a range of size ratios (4 < D/η < 16) for marginally light spheres. We find that the normalised acceleration PDF decreases in intermittency with increasing size ratio - in qualitative agreement with the predictions of the Faxén corrected model. We also present preliminary results on the rotational dynamics of large light spheres in turbulence

    C. V. Roman, Faculty Member

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    C. V. Roman, Faculty Member at Tennessee Agricultural and Industrial College Now Tennessee State University. He Is Also the Author of Meharry Medial College; a Historyhttps://digitalscholarship.tnstate.edu/library-digital-collections/1152/thumbnail.jp
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