7,739 research outputs found

    Fermi Coordinates for Weak Gravitational Fields

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    A Reference is corrected. (We derive the Fermi coordinate system of an observer in arbitrary motion in an arbitrary weak gravitational field valid to all orders in the geodesic distance from the worldline of the observer. In flat space-time this leads to a generalization of Rindler space for arbitrary acceleration and rotation. The general approach is applied to the special case of an observer resting with respect to the weak gravitational field of a static mass distribution. This allows to make the correspondence between general relativity and Newtonian gravity more precise.)Comment: 7 Pages, Preprint KONS-RGKU-94-04, LaTe

    Bibliometric review on the volatile organic compounds in meat

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    Meat flavor is an important aspect of meat quality that also influences consumer demand, and is therefore very important for the meat industry. Volatile organic compounds (VOCs) contribute in large part to the flavor of meat, and while increasing numbers of articles are published on this topic, reviews of these articles are very scarce. Therefore, our aim was to perform a bibliometric analysis of the scientific publications on VOCs in meat over the period 2000–2020. We selected 611 scientific sources from the Scopus database related to VOCs in meat (seafood excluded). The bibliometric information retrieved included journals, authors, countries, institutions, keywords, and citations. From this analysis, we drew up a list of the most important journals, authors, countries, and institutions, and the trends in VOC research on meat. We conducted a social network analysis (SNA) to identify the collaborations among the many authors and countries, and a keyword analysis to generate a network map of the authors’ keywords. We also determined which meat species were most frequently chosen as research subjects, traced the evolution of the various methods/instruments used, and explored the research tendencies. Finally, we point out the need for further research in defining meat quality, improving meat flavor, identifying adulterants, and certifying the authenticity of meat

    Measurements of a fast nuclear spin dynamics in a single InAs quantum dot with positively charged exciton

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    By using highly time-resolved spectroscopy with an alternative {\sigma}+/{\sigma} - laser pulse modulation technique, we are able to measure the fast buildup and decay times of the dynamical nuclear spin polarization (DNSP) at 5 K for a single InAs quantum dot (QD) with positively charged exciton. It is shown that the nuclear dipole-dipole interaction can efficiently depolarize DNSP with a typical time constant of 500 {\mu}s in the absence of external magnetic field. By using an external field of 8 mT to suppress the nuclear dipolar interaction, the decay time turns to be mainly induced by interaction with unpaired electron and extends to about 5 ms. In addition, it is found that the time constant of hole-induced depolarization of nuclear spin is about 112 ms.Comment: 5 pages, 3 figure

    Increasing Precipitation Decreases Water Use Efficiency of Alfalfa (\u3ci\u3eMedicago sativa\u3c/i\u3e L.) in a Semiarid Region

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    Alfalfa (Medicago sativa L.) plays an important role within the integrated farming systems in Northwestern Loess Plateau of China, because of its traits on a high productivity, prolonged growing season, and excellent nutritive value. However, water use efficiency (WUE) is a crucial indicator for forage production under different water conditions in the semiarid regions. To explore the responses of alfalfa growth and water use to precipitation variability, we set precipitation shelters to manipulate precipitation scenario as 30% precipitation increased (P+30), normal precipitation (CK), and 30% precipitation decreased (P-30) with the measurement of dry matter yield and soil water content. An alfalfa variety Zhongmu No.1 was sown in autumn of 2018 and harvested at flowering. Soil water was sampled in the depth of 0-2.0 m by a soil auger in 2019. The results showed that the total biomass yield for three cuts among the precipitation treatments had significant difference (P\u3c 0.05), with 12125.5, 11685.3, and 11167.2 kg ha-1 under treatment P+30, CK and P-30, respectively. The WUE of dry matter yield in P-30 treatment had the highest value, higher 25.5% and 10.3% than that in P+30 and CK treatment, respectively (P\u3c 0.05). We conclude that increasing precipitation could not improve the WUE of alfalfa, which indicates the wide adaptability of alfalfa in variable rainfall conditions in semiarid region

    Monotonicity results and bounds for the inverse hyperbolic sine

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    In this note, we present monotonicity results of a function involving to the inverse hyperbolic sine. From these, we derive some inequalities for bounding the inverse hyperbolic sine.Comment: 3 page

    Coherent versus Incoherent Light Scattering from a Quantum Dot

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    We analyze the light scattered by a single InAs quantum dot interacting with a resonant continuous-wave laser. High resolution spectra reveal clear distinctions between coherent and incoherent scattering, with the laser intensity spanning over four orders of magnitude. We find that the fraction of coherently scattered photons can approach unity under sufficiently weak or detuned excitation, ruling out pure dephasing as a relevant decoherence mechanism. We show how spectral diffusion shapes spectra, correlation functions, and phase-coherence, concealing the ideal radiatively-broadened two-level system described by Mollow.Comment: to appear in PRB 85, 23531
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