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排序方式: 共有167条查询结果,搜索用时 31 毫秒
131.
Libby J Martin L Powell A Wilkinson G Ecklund KM Love W Savinov V Mendez H Ge JY Miller DH Shipsey IP Xin B Adams GS Anderson M Cummings JP Danko I Hu D Moziak B Napolitano J He Q Insler J Muramatsu H Park CS Thorndike EH Yang F Artuso M Blusk S Khalil S Li J Mountain R Nisar S Randrianarivony K Sultana N Skwarnicki T Stone S Wang JC Zhang LM Bonvicini G Cinabro D Dubrovin M Lincoln A Naik P Rademacker J Asner DM Edwards KW Reed J Briere RA Ferguson T Tatishvili G Vogel H Watkins ME Rosner JL 《Physical review letters》2008,101(18):182002
We measure the mass of the eta;{'} meson using psi(2S)-->pi;{+}pi;{-}J/psi, J/psi-->gammaeta;{'} events acquired with the CLEO-c detector operating at the CESR e;{+}e;{-} collider. Using three decay modes, eta;{'}-->rho;{0}gamma, eta;{'}-->pi;{+}pi;{-}eta with eta-->gammagamma, and eta;{'}-->pi;{+}pi;{-}eta with eta-->pi;{+}pi;{-}pi;{0}, we find M_{eta;{'}}=957.793+/-0.054+/-0.036 MeV, in which the uncertainties are statistical and systematic, respectively. This result is consistent with but substantially more precise than the current world average. 相似文献
132.
Florent Bridier David L. McDowell Patrick Villechaise José Mendez 《International Journal of Plasticity》2009
Deformation micromechanisms of a Ti–6Al–4V alloy under fatigue loading at room temperature are studied using a three-dimensional crystal plasticity constitutive model. The model employs a minimum set of fitting parameters based on experimental data for Ti–6Al–4V. Single slip is strongly favored through a softening law that affects mainly the driving force for slip on the first activated slip system. Cyclic deformation behavior at the macroscopic scale and at the local scale of grains is analyzed through the simulation of 20 cycles of fatigue on a polycrystalline structure of 900 randomly oriented grains. The progressive activation of slip (basal, prismatic, and pyramidal) is analyzed and compared to experimental observations. 相似文献
133.
Florent Duchaine Simon Mendez Franck Nicoud Alban Corpron Vincent Moureau Thierry Poinsot 《Comptes Rendus Mecanique》2009,337(6-7):550-561
CHT (Conjugate Heat Transfer) is a main design constraint for GT (gas turbines). Most existing CHT tools are developed for chained, steady phenomena. A fully parallel environment for CHT has been developed and applied to two configurations of interest for the design of GT. A reactive Large Eddy Simulations code and a solid conduction solver exchange data via a supervisor. A flame/wall interaction is used to assess the precision and the order of the coupled solutions. A film-cooled turbine vane is then studied. Thermal conduction in the blade implies lower wall temperature than adiabatic results and CHT reproduces the experimental cooling efficiency. To cite this article: F. Duchaine et al., C. R. Mecanique 337 (2009). 相似文献
134.
Iris Trosien Enrique Mendez‐Vega Tobias Thomanek Wolfram Sander 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(42):14997-15001
The control of the spin states of molecules opens the path to tuning selectivity in chemical reactions and to developing novel magnetically switchable materials. 3‐Methoxy‐9‐fluorenylidene is a carbene that is generated in cryogenic matrices both in its lowest energy singlet and triplet states, and the ratio of these states can be shifted by selective irradiation. The interconversion of the nearly degenerate spin states is induced by a conformational change of the methoxy group: switching the methoxy group into the “up” position results in the singlet state and switching into the “down” position in the triplet state. The spin control via a remote functional group makes this carbene unique for the study of spin‐specific reactions, which is demonstrated for the hydrogenation reaction. Spin switching by switching the conformation of a remote functional group is a novel phenomenon with potential applications in the design of functional materials. 相似文献
135.
Zi-Yuan Li Carlos Jose Delgado Mendez Francesca Giovacchini Sadakazu Haino Julia Hoffman 《中国物理C(英文版)》2017,41(5):056001-056001
The Alpha Magnetic Spectrometer(AMS-02),which is installed on the International Space Station(ISS),has been collecting data successfully since May 2011.The main goals of AMS-02 are the search for cosmic anti-matter,dark matter and the precise measurement of the relative abundance of elements and isotopes in galactic cosmic rays.In order to identify particle properties,AMS-02 includes several specialized sub-detectors.Among these,the AMS-02 Ring Imaging Cherenkov detector(RICH) is designed to provide a very precise measurement of the velocity and electric charge of particles.We describe a method to reject the dominant electron background in antiproton identification with the use of the AMS-02 RICH detector as a veto for rigidities below 3 GV.A ray tracing integration method is used to maximize the statistics of with the lowest possible e background,providing 4 times rejection power gain for e background with respect to only 3% of signal efficiency loss.By using the collected cosmic-ray data,e contamination can be well suppressed within 3% with β≈ 1,while keeping 76% efficiency for below the threshold. 相似文献
136.
Rafaela Sponchiado Julia Medeiros Sorrentino Natlia Olegrio Sendy Sales Oliveira Leticia Malgarim Cordenonsi Gustavo Pozza Silveira Alexandre M. Fuentefria Andreas S. L. Mendez Martin Steppe Cssia V. Garcia 《Biomedical chromatography : BMC》2019,33(6)
The purpose of this paper is to describe the glycosylation of ambrisentan (AMB) by cultures of Cunninghamella elegans ATCC 9245. AMB is an endothelin receptor antagonist, which is used to treat pulmonary arterial hypertension. Filamentous fungi are morphologically complex and may exhibit different forms depending on the species and the nature of the culture medium. A biotransformation study was conducted to investigate the ability of C. elegans to metabolize AMB. Parameters were optimized by testing on different culture media and concentrations, pH, drug concentration, static and shaking conditions. Ambrisentan's metabolite, obtained after 240 h of incubation as a result of glycosylation pathway, was separated by HPLC and determined by high‐resolution mass spectrometry. The method showed linearity over 300–1000 μg mL?1 (r = 0.998). Accuracy, precision, robustness and stability studies agree with international guidelines. Results are consistent in accordance with the principles of green chemistry as the experimental conditions had a low environmental impact, and used little solvent. 相似文献
137.
Tailoring poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) microstructure and physicochemical properties by exploring its binary phase diagram with dimethylformamide
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Carlos. M. Costa Ana V. Machado Maria M. Silva Senentxu Lanceros‐Mendez 《Journal of Polymer Science.Polymer Physics》2015,53(11):761-773
Poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) (PVDF‐CTFE) membranes were prepared by solvent casting from dimethylformamide (DMF). The preparation conditions involved a systematic variation of polymer/solvent ratio and solvent evaporation temperature. The microstructural variations of the PVDF‐CTFE membranes depend on the different regions of the PVDF‐CTFE/DMF phase diagram, explained by the Flory‐Huggins theory. The effect of the polymer/solvent ratio and solvent evaporation temperature on the morphology, degree of porosity, β phase content, degree of crystallinity, mechanical, dielectric, and piezoelectric properties of the PVDF‐CTFE polymer were evaluated. In this binary system, the porous microstructure is attributed to a spinodal decomposition of the liquid‐liquid phase separation. For a given polymer/solvent ratio, 20 wt % , and higher evaporation solvent temperature, the β phase content is around 82% and the piezoelectric coefficient, d33, is ? 4 pC/N © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 761–773 相似文献
138.
Segundo Moran Irazu Gallardo-Wong Gustavo Rodriguez-Leal Paulina Mccollough Jorge Mendez Beatriz Castañeda 《Isotopes in environmental and health studies》2013,49(3):192-197
The aim of this study was to compare the oxidation of l-[1-13C]phenylalanine (13C-PheOx) in patients with chronic liver failure due to different etiologies using l-[1-13C]phenylalanine breath test. Breath samples were collected before the administration of 100 mg l-[1-13C]phenylalanine, and every 10 min thereafter until completion of 1 h. Control subjects (n=9) presented a larger cumulative percentage of 13C dose recovery (CPDR) than patients (n=124) with chronic liver disease, regardless of the etiology (7.5±0.7 vs. 4.2±0.2, p=0.001). No differences in CPDR were found considering the Child-Pugh (CP) class or etiology: alcoholic (CP A=7.7±0.7, CP B=4.1±0.5, CP C=2.0±0.3), hepatitis C virus (CP A=5.4±0.5, CP B=4.0±0.2, CP C=2.2±0.3), hepatocellular carcinoma (CP A=5.5±1.6, CP B=3.6±1.8, CP C=2.2±1.0); or cryptogenic cirrhotic patients (CP A=7.4±1.5, CP B=4.4±0.4, CP C=2.1±0.7). Results confirm that 13C-PheOx decreases in patients with cirrhosis with respect to controls, notwithstanding the etiology. 相似文献
139.
140.
Different areas of discrete mathematics lead to instrinsically different characterizations of planar graphs. Planarity is expressed in terms of topology, combinatorics, algebra or search trees. More recently, Schnyder's work has related planarity to partial order theory. Acyclic orientations and associated edge partial orders lead to a new characterization of planar graphs, which also describes all of the possible planar embeddings. We prove here that there is a bijection between bipolar plane digraphs and 2-dimensionalN-free partial orders. We give also a characterization of planarity in terms of 2-colorability of a graph and provide a short proof of a previous result on planar lattices. 相似文献