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31.
Abramowski A Acero F Aharonian F Akhperjanian AG Anton G Barnacka A de Almeida UB Bazer-Bachi AR Becherini Y Becker J Behera B Bernlöhr K Bochow A Boisson C Bolmont J Bordas P Borrel V Brucker J Brun F Brun P Bulik T Büsching I Carrigan S Casanova S Cerruti M Chadwick PM Charbonnier A Chaves RC Cheesebrough A Chounet LM Clapson AC Coignet G Conrad J Dalton M Daniel MK Davids ID Degrange B Deil C Dickinson HJ Djannati-Ataï A Domainko W Drury LO Dubois F Dubus G Dyks J Dyrda M Egberts K Eger P 《Physical review letters》2011,106(16):161301
A search for a very-high-energy (VHE; ≥100 GeV) γ-ray signal from self-annihilating particle dark matter (DM) is performed towards a region of projected distance r~45-150 pc from the Galactic center. The background-subtracted γ-ray spectrum measured with the High Energy Stereoscopic System (H.E.S.S.) γ-ray instrument in the energy range between 300 GeV and 30 TeV shows no hint of a residual γ-ray flux. Assuming conventional Navarro-Frenk-White and Einasto density profiles, limits are derived on the velocity-weighted annihilation cross section (σv) as a function of the DM particle mass. These are among the best reported so far for this energy range and in particular differ only little between the chosen density profile parametrizations. In particular, for the DM particle mass of ~1 TeV, values for (σv) above 3×10(-25) cm(3)?s(-1) are excluded for the Einasto density profile. 相似文献
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Calvo F Lépine F Baguenard B Pagliarulo F Concina B Bordas C Parneix P 《The Journal of chemical physics》2007,127(20):204312
Experimental kinetic energy release distributions obtained for the thermionic emission from C(n) (-) clusters, 10< or =n< or =20, exhibit significant non-Boltzmann variations. Using phase space theory, these different features are analyzed and interpreted as the consequence of contrasting shapes in the daughter clusters; linear and nonlinear isomers have clearly distinct signatures. These results provide a novel indirect structural probe for atomic clusters associated with their thermionic emission spectra. 相似文献
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Traditional grain size determination in materials characterization involves microscopy images and a laborious process requiring significant manual input and human expertise. In recent years, the development of computer vision (CV) has provided an alternative approach to microstructural characterization with preliminary implementations greatly simplifying the grain size determination process. Here, an end-to-end workflow to measure grain size in microscopy images without any manual input is presented. Following the ASTM standards for grain size determination, results from the line intercept (Heyn’s method) and planimetric (Saltykov’s method) approaches are used as the baseline. A pre-trained holistically nested edge detection (HED) model is used for CV-based edge detection, and the results are further compared to the classic Canny edge detection method. Post-processing was performed using open-source image processing packages to extract the grain size. In optical microscope images, the pre-trained HED model achieves much higher accuracy than the Canny edge detection method while reducing the image processing time by one to two orders of magnitude compared to traditional methods. The effects of morphological operations on the predicted grain size accuracy are also explored. Overall, the proposed end-to-end convolutional neural network (CNN)-based workflow can significantly reduce the processing time while maintaining the same accuracy as the traditional manual method. 相似文献
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Bordas und F. Touplain 《Fresenius' Journal of Analytical Chemistry》1914,53(6):393-394
Ohne Zusammenfassung 相似文献
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E. Walter und F. Bordas 《Fresenius' Journal of Analytical Chemistry》1912,51(9):597-598
Ohne Zusammenfassung 相似文献
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Eva Čadková Michael Komárek Jean Debord Loïc Della Puppa François Bordas Jean-Claude Bollinger 《Journal of solution chemistry》2013,42(5):1075-1082
We determined the acidity constants of tebuconazole and penconazole, two fungicides from the group of 1,2,4-triazoles. Potentiometric titrations were performed in a 20 % (v/v) acetonitrile/water mixture at 25 °C and at a fixed ionic strength (KNO3, 0.1 mol·dm?3). The pK a values (representing thermodynamic constants) were determined to be 5.0 ± 0.1 and 5.2 ± 0.1 for tebuconazole and penconazole, respectively. These values could be used in pure water solutions to consider the protonated or deprotonated forms when studying the field behavior of these fungicides. Molecular modeling calculations allowed identifying the N4 atom as the protonation site. 相似文献
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An annular neutron source offers the possibility of positioning a large sample, surrounded by a paraffin thermalizing shield, inside the central tube. The optimal shield/sample ratio is determined experimentally. The absolute value of the thermal neutron flux is determined by irradiating NaHCO3 and evaluating the induced24Na-activity by the sumpeak method. Average fluxes over the seven irradiation capsules are presented. Some current applications are discussed. 相似文献