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121.
Given a ribbon graph \(\Gamma \) with some extra structure, we define, using constructible sheaves, a dg category \(\mathrm {CPM}(\Gamma )\) meant to model the Fukaya category of a Riemann surface in the cell of Teichmüller space described by \(\Gamma .\) When \(\Gamma \) is appropriately decorated and admits a combinatorial “torus fibration with section,” we construct from \(\Gamma \) a one-dimensional algebraic stack \(\widetilde{X}_\Gamma \) with toric components. We prove that our model is equivalent to \(\mathcal {P}\mathrm {erf}(\widetilde{X}_\Gamma )\) , the dg category of perfect complexes on \(\widetilde{X}_\Gamma \) . 相似文献
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Tiziana Benincori Prof. Valentina Bonometti Dr. Filippo De Angelis Dr. Luigi Falciola Dr. Michele Muccini Dr. Patrizia R. Mussini Prof. Tullio Pilati Dr. Giovanni Rampinini Dr. Simona Rizzo Dr. Stefano Toffanin Dr. Francesco Sannicolò Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(30):9086-9098
The introduction of branching in multi‐thiophene semiconductors, although granting the required solubility for processing, results in an increased molecular fluxionality and a higher level of distortion, thus hampering π conjugation. Accordingly, branched oligothiophenes require rationalization of their structure–reactivity relationships for target‐oriented design and optimization of the synthetic effort. Our current research on spiderlike oligothiophenes affords deep insight into the subject, and introduces new, easily accessible molecules with attractive functional properties. In particular, a regular series, T′X Y , of five new multi‐thiophene systems, T′53 , T′84 , T′115 , T′146 , and T′177 , constituted by five, eight, 11, 14, and 17 thiophene units, respectively, their longest α‐conjugated chain consisting of tri‐, tetra‐, penta‐, hexa‐, and heptathiophene moieties, respectively, has been synthesized and fully characterized from the structural, spectroscopic, and electrochemical point of view. The electronic properties of the monomers and their electropolymerization ability are discussed and rationalized as a function of their molecular structure, particularly in comparison with the series of 5‐(2,2′‐dithiophene)yl‐persubstituted α‐oligothiophenes ( TX Y ) previously reported by us. These oligothiophenes are easily accessible materials, with promising properties for applications as active layers in multifunctional organic devices including solar cells. 相似文献
124.
Finazzi M Brambilla A Biagioni P Graf J Gweon GH Scholl A Lanzara A Duò L 《Physical review letters》2006,97(9):097202
We report experimental evidence for a transition in the interface coupling between an antiferromagnetic film and a ferromagnetic substrate. The transition is observed in a thin epitaxial NiO film grown on top of Fe(001) as the film thickness is increased. Photoemission electron microscopy excited with linearly polarized x rays shows that the NiO film is antiferromagnetic at room temperature with in-plane uniaxial magnetic anisotropy. The anisotropy axis is perpendicular to the Fe substrate magnetization when the NiO thickness is less than about 15 A, but rapidly becomes parallel to the Fe magnetization for a NiO coverage higher than 25 A. 相似文献
125.
Abraham J Abreu P Aglietta M Aguirre C Allard D Allekotte I Allen J Allison P Alvarez-Muñiz J Ambrosio M Anchordoqui L Andringa S Anzalone A Aramo C Argirò S Arisaka K Armengaud E Arneodo F Arqueros F Asch T Asorey H Assis P Atulugama BS Aublin J Ave M Avila G Bäcker T Badagnani D Barbosa AF Barnhill D Barroso SL Bauleo P Beatty JJ Beau T Becker BR Becker KH Bellido JA BenZvi S Berat C Bergmann T Bernardini P Bertou X Biermann PL Billoir P Blanch-Bigas O Blanco F Blasi P Bleve C Blümer H 《Physical review letters》2008,100(21):211101
The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV. 相似文献
126.
Abraham J Abreu P Aglietta M Aguirre C Allard D Allekotte I Allen J Allison P Alvarez-Muñiz J Ambrosio M Anchordoqui L Andringa S Anzalone A Aramo C Argirò S Arisaka K Armengaud E Arneodo F Arqueros F Asch T Asorey H Assis P Atulugama BS Aublin J Ave M Avila G Bäcker T Badagnani D Barbosa AF Barnhill D Barroso SL Baughman B Bauleo P Beatty JJ Beau T Becker BR Becker KH Bellido JA Benzvi S Berat C Bergmann T Bernardini P Bertou X Biermann PL Billoir P Blanch-Bigas O Blanco F Blasi P Bleve C 《Physical review letters》2008,101(6):061101
The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min. 相似文献
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Cannavò S Curtò L Lania A Saccomanno K Salpietro FM Trimarchi F 《Magnetic resonance imaging》1999,17(4):633-636
The simultaneous occurrence of multiple adenomas in the pituitary gland is a rare event. We report the coexistence of three non functioning pituitary microadenomas in a 37-year-old woman, referred to us for oligomenorrhea and headache. Biochemical evaluation revealed prolactin (131 U/liters), follicle-stimulating hormone (4.1 U/liters), luteinizing hormone (3.9 U/liters), 17beta-estradiol (74 pg/mL), free (2.0 pg/mL) and total testosterone (0.5 ng/mL), dehydroepiandrosterone-sulfate (3.5 microg/mL), 17OH-progesterone (0.8 ng/mL), cortisol (13.1 microg/dL), free triiodothyronine (4.8 pmol/L), free thyroxine (18.5 pmol/liters), thyrotropin (1.6 mU/L), and growth hormone (0.2 ng/mL) levels in the normal range, as for as the response to dynamic endocrine tests. MRI showed an enlarged sella turcica, occupied by three distinct hypointense areas that measured less than 5 mm in diameter in the left, medium and right side of the pituitary, respectively. This finding was confirmed 6 months later by a second MRI that revealed also a light increase in microadenomas dimensions. The patient, therefore, underwent neurosurgery by transfenoidal approach. Histologic examination showed no morphologic differences between the specimens obtained from the different microadenomas. Immunohistochemistry evaluation revealed a positive staining for the common alpha-subunit of glycoproteic hormones and negative for the other pituitary hormones tested, while electron microscopy showed cells with a poor secretory apparatus and a variable grade of cell differentiation. In conclusion, we report the fifth case described with multiple pituitary adenomas diagnosed in vivo and the first with three coexisting tumors revealed by MRI before neurosurgery. The occurrence of multiple pituitary tumors emphasizes the role of pituitary and extrahypophiseal factors in the clonal expansion of genetically altered cells. 相似文献
130.
Serventi S Allodi G De Renzi R Guidi G Romanò L Manfrinetti P Palenzona A Niedermayer Ch Amato A Baines Ch 《Physical review letters》2004,93(21):217003
We have measured the transverse field muon spin precession in the flux-lattice (FL) state of the two-gap superconductor MgB2 and of the electron doped compounds Mg(1-x)AlxB2 in magnetic fields up to 2.8 T. We show the effect of the two gaps on the internal field distribution in the FL, from which we determine two coherence length parameters and the doping dependence of the London penetration depth. This is an independent determination of the complex vortex structure already suggested by the STM observation of large vortices in a MgB2 single crystal. Our data agree quantitatively with STM and we thus validate a new phenomenological model for the internal fields. 相似文献